passage 405 is admitted through ports 189 @and 190 of pressure boost valve 180 to line drop si.-nal passage 406. Pressure drop valve 290 wi-@@i vary the pressure delivered to lin.- drop passage 409 inversely @with th,-ottle valve pressure actin.- on the end cf land 291 of valve 290. At heavy throttle, the pressure iTi pass,age 408 will drop off to permit the line pr--ssure to ris-- to 163 pounds. At Eght throttle the pressure in passage 499 will r-ise and cause the pr,-ssure regulator va'@Ne 55 to drop the li-@ie pressure to 115 po,,inds. !be pressure in passage 400 in r--vers-- are the s-,une as in low gear drive ra@Lio in order to provide adequate cipacity of the brakes for the high torque t-liey must resist. Fluid pressure j'rom passage 409 is admitted through restriction 1156 to passa,--. 410 and t@xough ports 211 and 210 of coupling timing valve 200 to couplin.- feed passaae 411 to fill t,ic coupling 11 with fluid. NVith reverse bralze 33 enga-,ed and couplin- 11 filled with flaid the transmission is conditioned for reverse operation. There has thus been provided a transmission cotitrol system wherein the line pressure is varied to different ran.-es of pressure in different drive ratios and one in which the coupling feed limit valve 220 is used particularly to accomplish a fast fill of coupling 11 duripg a heavy throttle shift from second to first gear or @from second to third gear. Band release accumulator 390 is controlled in accordance with chan.-es in throttle valve pressure to vary the tirr@e of release of th-- band 35 durin.- a shift from second to tl:iird. Part throttle valve 95 will be effective at part throttle openin.- to by-pass restr,'ction @131 to qdickly apply tle band, and effective at small throttle openin, to render restriction 131 efiective to delay application of band 35. Front clutch accumulator 315 is controlled by con-lpensator pressure to vary the clutch application in accordance with changes in engine developed torque. Band release valve 365 is controlled by compensator pressure and coupli@ig feed pressure to control th,-- release of band 35 in accordance with changes in engine developed torque and coupling pressure. In addition the accumulator 392 is provided with chamber 395 and a control chamber 393. First and second accumulator control valves 375 and 365 control the admission of fluid pressure to control chamber 393. In accomplishin.- a shift from seco-.id to th;rd drive ratio at closed throttle, valve 375 will del-iier fluid pressure to chamber 393 through ports 382 and 381 and v,,ill block off port 380. With a slightly advanced throttle, pressure in passage 4G7 Nvill position valve 375 to block oiT port 3S2 and connect port 381 to port 330. Passage 421 will initially be cor;-nected to exhaust tnrough ports 372 and 373 of accumulator control valve 365, passage 4ZO, and ports 2@12 and 213 of valve 209. As pressure in unit 11 and passage 411 rises, valve 365 will adnlit pressure from passage 41,8 to passage 419 through ports 371 and 372. Compensator pressure in passage 425 acting on land 367 4c@4t valve 365 assists pressure from passage 411 to position valve 365 to deliver pressure to passa.@e 419. Passage 419 is connected to passa,-e 421 through ports 38a, and 381 of vz@ve 375. It will b.- apparent that the action of accumi,.Iator 390 is varied with throttle openini,-. At closed throttle, @the accumulator is unable to stroke due to pressure in control chamber 3.93. At seght throttle openin.-I the accumulator Nvill stroke until such time that valve 365 delivers pressure to @chamber 393. Valve 3VI5 is controlled by pressure in passage 41]L and comi)e@isator pressure in passa,-e 425 so that t-he valve @will deliver pressure to chamb-.r 393 more quickly at heavy throttle opfning than is true at relatively Eght throttle opening. We c'iaim: 1. In a transmission havin@ planetary i earing and a plug rality of fluid pressure responsive drive establishing devices, said devices includir@g a hydrodynamic torque transmitting device, a clutch -and a brake, and fluid motors for 3,110,198 22 actuating said clutch and brake, respectively, a fluid pressure source, control valvin.- connected to said source and to said drive establishing devices @for controring the trapsmission drive ratio, said control val'ving being effective in a frst positio-.i thereof to deliver fluid pressure to said hydrodynamic torque transfer device and to said brake motor to establish a iirst transmission drive ratio, means for positioning said control valving in said first position, said control valvin@g being effective in a second 10 position to connect said hydrodynamic torque transmitting dev@'ce to exhaust and to direct Ruid pressure to said clu@ch motor and said brale motor to engage said clutch and brilce to establish a second transmission drive ratio, means for moving said control valving to said 15 second position, a chamber in said brake motor conn,-cted to sa,d valving and adapted to receive fluid under pressure to releas-. said brake, said valving being effective in a thl:rd position to direct fluid to said hydrodynaniic torque transriitting device to @fill said device, 20 to direct fluid to said clutch motor to en@.a.@e said clutch, a-id to direct fluid to said brake motor charib-.r to release sa-d brak-e, and means for moving said control valvin,- to said third position. 2. In a transmission having planetary gearing and a 25 plurality of fluid pressure responsive drive establishing d,-vices includip.@ a clutch, a brake, a hydrodynamic torqie tiansmitting unit and fluid motors for actuating sa:Ld clutch Pnd brale, respectively, a fluid pressure source, cotitrol valvin.- connected to s@aid sourc-., said hydro30 dynamic torwie transmitting unit, and said fluid motors for controll-'ng the transmission drive ratio, said brake motor incltiding an apply chamber adapted to receive fluid to en -age said brake and a release chamber adapted to receive fluid to release said brake, said control valv35 ing bein.- effective in a first position to deliver fluid pr.-ssdre to said clutch motor and said brake n-lotor apply chamb--r to establish one transmission drive ratio, means yieldably biasin.- said control valving to said first posiion, said control valving being effective in a second 40 position to deliver fluid press!ure to said clutch motor, said brake @apply and release chair-bers and said hydrodynamic torque transmitting unit to establish a second drive rat-o, said brake being released by fluid pressure supplied to said release chamber when said valving is 4,5 eifect-1ve to deliver fluid pressure to said clutch motor and to said hydrodypamic torque 'transmitting unit, and mear@s for moving said control valving from said first to said second position. 3. In a transmiss;on having planetary gearing and a 50 pliirality of i9u,Ld pressure responsive drive establishin.@ dc,,,ices for estabhshing - first, second and third drive ratios includ@ng a clutch, a brake and a hydrodynamic torque trari-smittin.a unit and fluid motors are actuating sa:ld c'@utcn and brake, respectively, a fluid pressure source 55 control valving connected to said source, said hydrodynan-iie torque transm;tting unit and said fluid motors f-or conlrolling the transmission drive ratio, said control valving bein,- effective in a first position to deliver fluid pressiire to said hydrodyn@amic torque transmittiing unit 60 and said brake motor to engage said brake to establish a first tralismision drive ratio, means yieldably biasin.said control valving to sa;d first position, said control valvin.- being effective in a second position to connect said hydrody@iainic torque transmitting unit to exhaust 65 and to deliver fILlid pres.-ure to said clutch motor and said brak-e motor to ep@,a,- P- the same to establish !a second drive ratio, meais for moving said control valving to said second position, said control valving being effective in a third positior, to deliver fluid pressure to said 70 hydrodynamic torque transriaittin@g unit and to said c'iutch motor to render said unit and clutch effective to establish dri-,,e t'@,erethrough and to deliver fluid pressure to said bra@ke motor to release said brake to establish a third transmission drive ratio, and @means for positioning 75 said control vilving in said third position.

23 4. In a transniiss,'@on havin.- planetary gearin,@ and a plurality Gf drive establishing devices including a hydrodyna@@mic torque tra-@isn-litting unit, a cl-Utch and a brake, a ffuid pressure responsive brake motor for actuating said brake, a fl-aid press,,lre responsive clutch motor for actuating said clutch, said brake mo,or h-aving a first control chamb.-r adapted to receive Itluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release said brake, a fluid pressure source, control valvir..- conn-.cted to said source, said hydrodynamic torq-Lie trar,.sfer un-it and said fluid motors for controlling the transmission drive ratio, said control valvin,,- being effective in a first condition of operation to deliver fl-d-id to saild hydrodynaniic torque transfer unit and to said first coiltrol charibp-r of sa-ld brak-e motor to engage said brake to establish f.rst gear drive, means for positioning sa;d cor,.trol valvin,,- to establish said first condition of on@ration, said control valving bein,- effective in a second condit@'.on of operation @to co.@mect said hydrodynamic torque trans@fer -unit to exhaust and to deliver fluid prcssure to said clutch motor,and said brake motor to en.-a.@e said clutch and brak-e to establish second igear drive, means for positionin,- said control valv-in.@ to establish said second condit,@on of operation, said control valv;ng being effective in @a third condition oll oli-,ration to deliver ffuid pressure to said hydrodynamic torque transfer unit, to said clutclh motor and to said see-ond fluid che-,riber of said brake -notor to establish drive throlgh sa-id clutch and said I-lydrodynamic torque transf--r uiiit and to release sa-.d brake, and means for positioring sai-d control valvitig to establish said third condition of op--ration. 5. In a tpansm;ssion having planetary gearing and havin- a plurality of drive establishing devices includ;ng a lhydrodynamic torque tra.-.sf.-r unit, a clutch and a brake fluid pressure responsive motors for actuating said clutch and brake, respectively, said brake motor having a iirst control chamber adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release said brake, ;a fluid pressure source, control valving connected to said source, to said clutch motor, and to both of said chambers of said brake riotor for controllin.- the transn-iission drive ratio, said control va@lving being effective in one condition of operation to deliv--r fluid pressure to said hydrodynarrdc torque trans,.Ier unit and to said first bra'@,C control chamber to establish idrive through said hydrodynamic unit and to engage said brake, nieans for positioning said control val@.,in.- in a first position to establ-ish said on-- condition of operation, said control valving bein.- effective in a seco-@id condit:on of operat@'.on to deliver fluid pressure to said Ilutch @riotor, to said first brake control chamber, and to connect said hydro,dynamic torqlie transfer unit to exhaust to establish drive through said clutch, Treans for moving said control valving to a second position to establish said second condition of operation, said contrl valving beirg effective in a third condition of operation to deliver fluid press-ure to said hydrodynamic torque transfer unit, said clutch motor and to said second brake control chamber to establish drive through said hydrodynamic torque trans'ier unit and said clutch, and means for moviii.- said control valving to a third position to establish said third condition of operation. 6. In a transmission having planetary gearin.@ and a plurality of drive establishing devices including a hydrodynarnic torque transfer unit, a clutch :and a brake, a clutch- servo adapted to receive fluid presslire to engage said clutch, a brake servo -'Lor en.-aging and releasing said brake, said brake s-@rvo having a first control chamber adap,ed to receive fluid pressilre to apply said brake and a second control chamber -adapted to receive fluid pressure to release said brake, a fluid pressure source, control valving connected to said source, to said hydrodynamic torqt,.e transier un:lt, to said clutch servo, @,,nd 24 to both oj' said control chambers of said bral-e servo for controlling the transmissiori drive ratio, said control valvinl- b@-in,- effective in one condition of operation to de-iver fliiid pressure to said hydrodynamic torque transfer u,n@t and to said first brake control chamber to establish drive through said hydrodynamic torque transfer unit a-,id to en.-a.-e said brake, means for positioninl- said control valving to establish said one conditioil of operation, said control valving being effective 10 in a seco@ld co-D-dition of operation to deliver fluid press,,,.re to sa;d cl,,it-,h servo and said first brake control charpb--r and to connect said hydrodynam,.c torque tr@ansfer -u-Aiit to eyhaust to establish drive throu.-Ii said clutoh, m@--,ns for positioning said control valving to establish 15 said seco-@id condition of operation, said control valving bein-- e@'1-.ct-ive in a third position to direct fluid pressure to sa,.d clutch servo, said hydrodynamic torque transfer tin:it and to sa;d s-,cond bral@e control chamber to establish drive through sa-ld hydrodynatnic torque transfer 20 uri,@t and sa@;d clutch, means for movin.- said control valvin.- to said th@rd position, and manually controlled means for controlling the pr.-ssure value of fl,,iid pressure effective in second brake control cha-mber to vary the release of said bra-ke. 25 7. In a trapsrriission having planetary gearing and a pl@uralily of drive establ;shii,,a, devices including a hydrodyn2-.-i-iie torque traisfer unit, a clutch and a brake, a clutch servo adai)ted to receive fluid pressure to engage said clutch, a brake servo for actuating said brake, 30 said brake servo havinig a ilrst co@itrol chamber adapted to r6ceive fl-,,-Id pressure to apply said brake and,a second control chamber adap,cd to r=ive fluid pressure to re',-.ase said brake, a fltiid pressure source, control valving con-tiected to said source, to said hydrodynamic torque 35 transfer unit, to said cutch servo and to both of said bral-e servo co-Titrol chambers for controlling the transrnission d.-ive ratio, said control valv;ng being effective in ope cond,.tion of op-.ration to deliver fluid pressure to said hydrodynamic torque transfer unit and to said4( first bra,',e servo control ciia-mb,-r to establish drive t.arough sa-ld hydrodynam;C torque transfer unit and to engage said brake, sa;d control valving being effective in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control 45 chamber and toconr@ect saidhydrodynamic torqtie transfer unit to exhaust to establish drive througli said cl-utch, said control valvirg b-,ing effectiie in a third position to direct fiuid pressure @,0 said clutch servo, said hydrodynamic torque transfer unit and to said second brake 50 control chamber to establish drive through said hydrodynam;.c torque transfer unit and said clutch, an accuiliulator hydraulically connected to said se,-ond brake control chamber for controllin.- the, pressure in said chamber, manually operable valve means for varying 55 th.- act-'@on oll said accumulator, means for posit-.onin.@ said control valving in a first position to establish said one conditioi-i of operatio-@il and means for moving said control valv,.ng to a second position and to said third position to establish said second and third condition of 60 operation, resp,-ctively. 8. In a transm;ssion having planetary gearing and a plurality of drive establishing devices 'Mcluding a hydrodynamic torque transfer unit, a clutch and a brake, a clutch servo for ac@Uating said clutch and,a brake servo 65 for actuatin.- said brnke, said brake servo having a first con,rol chainber adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive iluid pressure to rel.-ase said brake, a flti,d pressure source, control valv;ng connected to said source, to said 70 hydrodyna-inic torque transfer unit, to said clu'Lch servo and to both of said brake servo control chambers for controli-iig ',he trarsi-iiission drive ratio, said control valvi-ii.a being eff--ctive iTi one condition of op@-ration to deliver ipuid pressure to said hydrodynamic torque transfer unit 75 Ind to said first bra-Lce control chamber to establish drive

25 through said hydrodynamic torque transfer unit and to en,@age said brake, means for positioning said control valvin-- to establish said on,3 condition of operation, said contr@l' valving being effective in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to connect sa@.d hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for moving said control valvin-. to a second position to establish said second condition of operat:@on, said control valving bein@ effective in a third position to direct fluid pressure to said clutch servo, said hydrodynamic torque transfer unit and to sa;d s--cond brake control chamber to establish drive through said hydrodynamic torque transfer unit and said clutch, means for moving said control valving to said third position, an accurr@il-lator hydraulically connected to said second brake control chamber for con,Lrolling the pressilre in said chamber, an additional valve for controlling said accumulator, and a manuary operable valve for co-.ltrolling the action of said additional valve. 9. In a transmission having planetary gearing and a plurality of drive establishing devices including a hydrodynar.iie torque transfer unit, a clutch aid a brake, a fluid pressure responsive clutch servo for actuatin- said clutch, a fluid pressure responsive brake servo for actuating said brake, said brake s-.rvo baving a first control chamber adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release sa;d brake, a fluid pressure source, control valving connected to source, to said hydrodynamic torque transfer unit, to said clutch servo, and to both of said brake servo control chambers for controlling the transmission drive ratio, said control valvin.- being efiective in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake con'trol chamber to establish drive through said hydrodynamic torque transfer unit and to en.- age said brake, means for positioning said control valving in a first position to establish said one condition of operat;on, said conlrol valving bein.- effective in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to connect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for positionin.- said control valvin.- in a second position to establish sa@d second condition of operation, said control valving being effective in a third position to direct fluid pressure to said clutch servo, said hydrodynamic torque transi:er unit and to said second brake control chamber to establish drive throu.-h said hydrodynamic torque transfer unit and said clutch, means for positionin.- said control valving in said third position, an accumulator having a chamber hydraulicahy connected to said second brake control chamber, an accumulator control chamber, and a manlially controuable valve for controlling the admission of fluid pressure to and exhaiist of pressure from said accumulator control chamber to vary the action of said accumulator. 10. L-1 a transmiss-lon havin.- planetary gearing and a plurality of drive establishing devices includin.- a hydrodynamic torque transfer unit, a clutch and a brake, a fluid pressure responsive clutch servo for actuatin,@ sa;d clutch, a brake servo for actuating said brake, said brake ser-vo having a first control cnamber adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release said brake, a fluid pressure source, control valving connected to said source, to said hydrodynamic torque transfer unit, to said clutch servo and to both of said brake servo control chambers for controlling the transmission drive ratio, said control vqlvin.- being effective in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drive through said hydrodynamic torque transfer un;t and to enga@,e said brake, means for posi3,110,198 26 tiotiing said control valving in a first position to establish sa;d o-@ie condition of operation, said control valving be;ng effective in a second condition of operation to deliver flu@@d pressure to said clutch servo and said first brake control chamber and to connect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for posit-onin.- said control valving in a second position to establish said second condition of operation, said control valving being effective in a 10 third position to direct fluid pressure to said clutch servo, said h,,,drodynamic torque transfer unit and to said second brake control chamber to establish drive through said hydrodynamic torque transfer unit and said clutch, means for posilioning said control valving in said third position 15 to establish a third transmission drive ralio, an accumulator having a cliamber hydrail-lically connected to said second brake control chamber, an accumulator control chamber, a valve for controlling the admission of fluid pressure to and exhaust of pressure from said accumu20 lator control chamber, said valve being effective in one position to connect said accumulator conrol chamber to exlaaust and movable in response to fluid pressure in said hydrodynam;c torque transfer utlit to deliver fluid pressure to said accumulator control chamber. 25 1 1. In a transmission havin.- planetary geaxing and a plural,' ty of drive establishin@- devices including a hydrodyna-@n-ic +,Orque transfer unit, a clutch and a brake, a fluid pressure responsi-,,e clutch servo for actuating said clutch and a fluid pressure respo-@isive brake servo for 30 actua@,ing said brake, said brake servo havin.- a first control cbamber adapted to receive fluid pressure to apply said brale and a second control chamber adapted to recei-ve fluid pressure to release said brake, a fluid pressure sourc@-, control valving connected to said source, 35 said hydrodynamic torque transfer unit, said clutch servo and to both of said bral,-e servo control chambers for controllin.- the transmission dri-,@e ratio, said control valvin.- being eff-@ctive in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit 40 and to said first brake control chamber to establish drive through said hydrodynamic torque transfer unit and to engage said brake, means for positioning said control valving in a first posit;on to establish said one condition of op@-ration, sa- @d control valving being effective in a 45 second condition of operation to deliver fluid pressure to said clutch s@-rvo and said first brake coitrol chamber and to connect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for mov;ng sa-.d control valvin.- to a second position to 50 establish said s@-cond condition of operation, said control valving bein- effective in a third position to direct fluid pressure to said c'jutch servo, said hydrodynamic torque transfer unit and to said second brake control chamber to establish drive throu,@h said hydrodynamic torque 55 transfer unit and said clutch, means for moving said control valvin,@ to said third positio-@i, an accumulator having a chamber hydraul,'@cally connected to said second brake control cbamber, an accumulator control chamber, means for controllin.- the admission of fluid pressure to and ex60 haust of pressure from sa;d accumulator control chamber includin.- an accurrulator control valve, means yieldably biasing said accumulator control valve ',o connect said accumulator control chamber to exhaust, said accumulator control valve being mov@ble in response to fluid 65 pressure in said hydrodynamic torque transfer unit to connect said accumulator control chamber to said fluid pressure source, and additional manually op@,rable means for controlling said accumulator control valve. 12. In a transmission having planetary gearing and a 70 plurality of dr-.'ve establishing devices including a hydrodynamic torque transfer unit, a clutch and a brake, a flu-id pr@-ssure responsivc clutch servo for actuating said clutch and a fluid pressure responsive brake servo for actua,ing said brake, said brake servo having a first con75 trol chamber adapted to receive fluid pressure to apply

said brake and a second control char@iber adapted to rec.-ive fluid pressure to reease said brake, -,t fluid presslre source, control valvina connected to said source, said hydrodynamic torque trans.'Ler unit, said clutch servo, and to both of said brake servo control chamb@-rs for controlling the transinission drive ratio, said control valving beineffective in one condition of operation to deliver flu., pressure to said hydrodynam@c torqu@- transfer id unit and to said first brake control chariber to establish drive throu,@h said hydrodynamic torque trailsfer unit and to en-.a.-e said brake, means for pos@' tion-@'r.,g said control valving in a firs' position to establish said one condition of operation, said control valvin.- being effectiie in a second condition of operation to deliver fluid pressure to sa;d clutch servo and said 4!rst brake control chamber and to com-iect said hydrodynam;.c torque traiisfer un;t to exhaust to establish drive through sa,.d --Iutch, means for moving said control valvin.- to a second pos@'tion to establish said second condition of operation, said control valving being e.,Tective in a third posi@ion to direct fluid pressure to said clutch servo, sa;d hydrodynamic tor,,lue transf--r unit and to said second brake control chamb-.r to establish dr-i,,re throu,-'n said hydrodynamic torque transfer unit and said ciu+ch, mear@s for moving said control valvin- to said third posifion, an accumulator having a ciianiber hydraulically connected to said second brak-. contrbl chamber, an accumu'@ator control chamber, means for controlling 'Lhe admiss-icii of flu-id pressure to and exiiaust of pressur-. from said second accumulator confrol chamber including first and s--cond valves, said first vaIN,-bein.- effectiie in one operative position to dire,-t ffuid p,-cssure to said accumulator con@rol chamber, manually operable m--ans for controlling the position of sa-id -,9rst valve, said second valve being eff-,ctive in one position to deliver fluid pressure to said accum-ulator control chamber through said first valve and effeefive in a second position to connect said accui-nulator control chamber to exhaust, and means including manually operable means for controllin,- the position of said second valve. 13. In a transmission having plan-@tary gearing and a plural:ty of drive establishing devices including a hydrodynamic torque transfer unit, a clutch and a brake, a fluid pressare respo,-isive clutch servo for actuating said clutc'n, a fluid pressure resp-onsive brake servo for actuating sa;d brake, said brake servo having a first conlrol chamber adap@ed to receive f-luid 1)ressure to apply said brake and a s-- cond control cham@er adapted to receive flu;d presslre to release said brake, a fluid pressure source, control vaiving connected to said source, to said hydrodynamic torque transfer ulit, to said clutch servo and to both of said brake servo control chamb-.rs for controlling the transmissio-ri drive ratio, said control valving be;ng effective in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drive through said hydrodynam;c torque transfer unit and to enga.-e said brakc, means for positioning said control valving in a first positio@l to establish said one condit-ion of operation, said control valving being effec,live in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to connect said hydrodynainic torque transfer unit to exhaust to establish dr;v@, through said clutch, means for moving said control valvina. to a second position to establish said se@ond conditio-@i of operation, said control valvin.- being effective in a third position to direct fluid pressur-- to said clutch servo, said hydrodynamic torque transfer unit and to said second brake control chamber to estabiish drive througn said hydrodynamic torque transt'er unit and said cluten, means for moving said control valvin.- to said third position, an accumulator havin.- a chamber hydraulically connected to sa:ld second brake control ch-amber, an accumulator control chaniber, means for controlling the adm;ssion of fluid pressure to said accumulator conlrol chamber including first and second accumulator cor.,trol valves, means yieldably biasing said first accumulator control valve to a first position to connect said accumulator control chamber to said fluid pressure solrce and to block off said accumulator control cha-nber from said second accumulator control valve, maiually operable means for positioning said fust accumul,-ttor control valve i-.i a second position to connect sa@d ac--umulator control chamber to said second accumulator control valve, means yieldably biasing said second 10 accumulator control valve to connect said acclimulator corirol chamber to exhaust vihen said first control valve is disnosed in said second positio.,i, said second accumulator conllrol valve bein.- movable in response to pressiare in said hydrodynamic torque transfer unit to deliver pres15 su-re to said accumulator conlroi cbamber through said iirst a-,cumulator control valve when said first accumulator control valve is disposed in said second position. 14. In a transmission having planetary gearing and a pl,-lrality of drive establishina devices including a hydro20 dynamic torque transfer unit, a clutch and a brake, a fluid pressure responsive clutch servo for actuating said clutch, a fluid pressure responsive brake servo for actuating said brake, said brake servo having a first control chamber adi.,,oted to receive fluid pressure to apply said brake and 25 a second control chamber adapted to receive fluid pressure to release said brake, a fluid pressure source, control valving connected to said source, to said hydrodynamic torque trarsfer unit, to said clutch servo and to both of said brake servo control chambers for controlling the transmission 30 dri-,,e rat@'@o, said control valving being effective in one condition of o-Deration to deliver-fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drine through said hydrodynamic torque transfer unit and to en.aage said brake, means for 35 pbsilioning said control val-,7ing in a first position to establish said o-.i@- condition of operation, said control valving being effective in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to connect said hydrodynanii@ torque 40 transfer unit to exhaust to establish drive through said clutch, means for moving said control valving to a second position to establish said second condition of operation, said control valving being effective in a third position to direct flu-'@d pressure to said clutch servo, said hydro45 dynamic torque transfer unit and to said second brake control chamber to establish drive through said hydrodynamic torque trans,Ler unit and said clutch, means for moving said control valving to said third position, an acclimulator having a chamber hydraulically connected 5o to said second brake control chamber, an accumulator control chamber, means for controuing the admission of fluid pressure to said accumulator control chamber including first and second accumulator control valves means yieldably biasing said first accumulator control @alve to a first 55 position to connect said accumulator control chamber to said flu;d pressure source and to block off said accumulator control chamber from said-second accumulator control valve, manually operable means for positioning said first accumu ator contro v m a second pos to connect 60 said accumulator control chamber to said second accumulator control valve, means yieldably biasing said second accumulator control valve to connect said accumulator control chamber to exhaust when said first control valve is disposed in said second position, said second accumula65 tor control valve being movable in response to pressure in said hydrodynamic torque transfer unit to deliver pressure to said accumulator control. chamber through said first accumulator control valve when said first accumulator control valve is disposed in said second position, and addi7o tional manually operable means for assisting tne pressure in said hydrodyiiamic torque transmitting unit to position said second accumulator control valve to deliver fluid pressure to said accumulator control chamber. 15. In a transmission having planetary geari:ng and a 75 plurality of drive establishing devices including a hydro-

29 dynamic torque transfer unit, a clutch and a brake, a fluid pressure respons@.ve clutch servo for actuatin-, said clutch, a fluid pressure responsive brake sei-vo for actuating said brak-e, said brake servo having a first control chamber adapted to receive fluid pressure to apply said brale and a second control chamber adapted to receive ffuid pressure to release said brake, a fluid pressure source, control valving connected to said source, to said hydrodynamic torque tratisier unit, to said clutch servo and to both of said brake servo control chambers for controllin.- the transmission drive ratio, said control valving being effective in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drive through said hydrodynamic torque transfer unit and to er.ga.-e said brake, means for positioning said control valvin.- in a first position to establish said one condition of operation, said control valving being effective in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to coinect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for moving said control valving to a second position to establish said second condition of operation, said control valving being effective in a third posilion to direct fluid pressure to said clu' ch servo, said hydrodynamic torque transfer unit and to said second brake control chamber to establish drive through said hydrodynamic torcue transfer unii and said clutch, means for moving saia coiatrol valving to said third position, an accumulator having a chamber hydraulicafly connected to said second brake control chamber, an accumulator control chamber, riieans for controllin,-,the adn-tission of fluid pressure to and exhaust of pressure from said accumulator control chamber includin.- first and second accumula-tor control valves rr@eans yieldably biasing said first accumulator controi valve to a first position to connect said accumulator control chamber to said fluid pressure source -and to block off said accumulator control chamber from said second accumllator control valve, means ipcluding a manually controlled valve for positioning said first accu-mulator control valve in a second position to block off said accumulator control chamber from said fluid pressure source and to connect said accumulator control chamber to said second accumulator control valve, means yieldably biasing said second accumulator control valve to connect said accumlilator control chamber to exhaust when said first accumulator control valve is dn said second position, said second -accumulator control valve bei3a@ rr@,ovable in res@ronse to rise in pressure in said hydrodynam-ic torque transmittin@ unit to -a second position to deliver fluidpressure to said accumulator con@trol chamber through said first accumulator control valve when said first accumulator control valve is in its second position. 16. In a transmission ha7ving planetary gearing and a pli-irality of drive establishin.- devices includin.-. a hydrodynar.qic torque transfer unit, a clutch and a brake, a fluid pressure responsive clutch ser-vo for actuating said clutch, a fluid pressure responsive brak-e servo for actuating said brake, said brake servo having a first control chamber adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release said brake, a iluid pressure source, control valving connected to said source, to said hydrodynamic torque transfer unit, to said clutch servo and to both of said brake servo control chambers for coTitrolling the transmission drive ratio, said control valving bein.- effective in one condition of op--ration to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drive throu.-h said hydrodynamic torque transfer unit and to en-.age said brake, means for positionin.- said cor@trol valvin.- in a first position to establish said one condition of operation, said control valving being effective 3,110,198 30 in a second condition of operation to deliver fluid pressure to said clutch servo and said first brake control chamber and to co-inect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for moving said control valving to a second position to establish said second condition of operation, said control valving being effective in a third position to direct fluid pressure to said clil-tch servo, said hydrodynamic torque transfer unit and to said second brake control 10 chamber to establish drive through said hydrodynamic torque transfer unit and said clutch, means for moving said control valvina, to said third position, an accumulator having a chamber hydraulicafly connected to said second brake control chamber, an accumulator control chamber, 15 means for controuin.- the admission of fluid pressure to and exhaust of pressure from said accumulator control chamber including first and second accumulator control valves, means yieldably biasin.- said first accumulator control valve to a first position to connect said accumu20 lator control chamber to said fluid pressure source and to block off said acelmulator control chamber from said second accumulator control valve, means including a manually controlled valve for positioning said first accumulator co-.ltrol valve in a second position to block 25 off said accumtilator control chamber from said fluid pressure source and to connect said acci-imulator control chamber to said second accumulator control valve, means yieldably biasing said second accumulator control valve to connect said accumulator control chamber to 30 exhaust -,vhen sa@'@d first accumulator control valve is in said second position, said second accumulator control valve being movable in response to rise in pressure in said hydrodynamic torque transmitting unit to a second position to deliver fluid pressure to said accumulator 35 control chamber through said -first accumulator control valve when said first accumulator control valve is in its second position, and means including a further manually controlled valve for delivering variable pressure to said second accumi,-Iator control valve, said variable pressure 40 acting in assistance to said pressure in said hydrodynamic toreue transmitting un;t to pbsition sa;d second accumulator control valve to deliver fluid pressure to said acc@.imulator control chamber. 17. In a transmission having planetary gearing and a 45 pl@arality of dr;.ve establish,.ng devices including a hydrodynamic torque transfer unit, a clutch and a brake, a fluid pressure responsive clutch servo for actuating said clutch, a fluid pressure responsive brake ser-vo for actuating said brake, said brake servo having a 'first control chamber 50 adapted to receive fluid pressure to apply said brake and a second control chamber adapted to receive fluid pressure to release said brake, a fluid pressure source, control valvin.a connected to said source, to said hydrodynamic torque transfer unit, to said clutch servo and 55 to both of said brak-- servo control chambers for controlling the transmission drive ratio, said control valving being effective in one condition of operation to deliver fluid pressure to said hydrodynamic torque transfer unit and to said first brake control chamber to establish drive 60 throu.-h said hydrodynamic torque transfer unit and to en.-a-,e said brake, means positioning said control valving in a first position to establish said one condition of operatiol,, said control valvin-, being effective in a second condition of operation to del;ver fluid pressure to 65 said clutch servo and said first brake control chamber and to connect said hydrodynamic torque transfer unit to exhaust to establish drive through said clutch, means for moving sa;d control valving to a second position to establish said second condition of operation, said control 7o valving being effective in a third position to direct fluid pressure to said clil-tch servo, said hydrodynamic torque transfer unit apd to said second brake control chamber to establish drive through said hydrodynamic toritie transfer unit and said clutch, means for moving said 75 control valvin.- to said third position, an accumulator

having a chamber hydraulically connected to said second brake cont.@ol chamber, an accum-,ilator control chamber, means for controlling the admission of fluid pressure to and exhaust of pressure from said accumulator control chamber includin-, first and second accumulator control valves, mear@s yieldably biasing sa;d first accumulator co.itrol valve to a first pos,.tion to connect said accumulator control chamber to said fliiid pressure soarce and to block off said accumulator control chamber from said second accumulator control valve, means including a manually controlled valve i'Or positioning said first accumulator control valve in a second position to block off said accumulator control chamber from said fiuid pressur,- source and to connect said accumulator control chamber to said second accumulator control valve, means yieldably b-lasing sa@.d second accumulator control valve to connect said accumulator control chamber to exhaust when said first accum-alator control valve is in said second position, said second accumulator control valve bein,@ movable in response to ris-. in pressure in said hydrodynarp-ic torque transmitting unit to a second position to deliver fluid pressure to said accumulator control chamber through said first accumulator control valve when said first accuniiilator control valve is in its second position, and means includip-, a further valve controll.-d by said mani-lally controlled valve for delivering variable pressure to said second accumulator control valve, said variable pressure acting in assistance to said press,-,re in said hydrodynamic torque transfer urit to position said second accumulator control valve to deliver fluid pressure to said accumulator control chamber through said first accumulator cor@trol valve. 18. In a transmiss;on having planetary gearing and a plurality of drive establishing devices including a hydrodynamic torque transmitting unit, a clutch and a brake, a fluid pressure responsive clutch servo for actuatin- said clutch, a fluid pressure responsive brake servo for actuating said brake, said brake servo having a first control chamber adapted to receive fluid t)ressure to apply said ambrake and a second control ch ber adapted to receive fluid pressure to release said brake, a fluid pressure source, control valving connected to said source, to said hydrodynamic torque transfer unit, to said clutch servo and to both of said brake servo control chambers for controlling the transmission drive ratio, said control valving being effective to deliver ffuid presusre to said hydrodynamic torque transmitting unit and to said first brake servo control chaniber to establish a first transmission 32 drive ratio, means positioning said control valving in a frst position to establish said first drive ratio, said control valving being effective to deliver fluid pressi-ire to sa,.d clu'Lch servo and to said first brake control chamber and to connect said hydrodynamic torque transmitting unit to exhaust to estabesh a second transmission drive ratio, means for positioning said control valving in a second position to establish said second drive ratio, said control valving bein-. effective to liver i pressure to io said hydrodytiamic torque transm;.tting unit, said clutch s--rvo and sa;d second brake control chamb-.r to establish a third transmission drive ratio, means for positioning said control valvin.- in a third position to estabesh said third transmission drive ratio, an accumulator having 15 a chamber connected to said second brake control chamber ard having an accumulator control chamber, means for controllirg the admission of fluid, pressure to said accumulator control chamber including first and second accumulator control valves, means yieldably biasin.- said 20 first acclimulator control valve to admit fluid pressure to said accumulator control chamber, a manually operable valve for delivering variable pressure, said first accumulator control valve being movable in response to fluid presstire delivered by said manually operable valve to 25 connect said accumulator control chamber to said second accumulator control valve, means yieldably biasing said s,-cond accumulator control valve to con-.icct sa-id accumulator control chamber to exhalist, said second accumulator control valve being movable in response to 30 press-Lire in said hydrodynamic torql-ie trar,.smitting unit to direct fluid pressure to said accumulator control chamber throu.-h said first accumillator control valve, and an add;tional pressure metering valve controued by the variable pressure delivered by said first pressure metering '3 5 valve adapted to deliver variable pressure to said second accumulator control valve, the variable pressure dehvered by said additional pressure metering valve acting in assistance to the pressure in said hydrodynamic torque transmitting unit to position said second accumulator con40 trol valve to direct fluid pressure to said accumulator control chamber. References Cited Lri the file of this patent 45 UNITED STA.TES PATENTS 2,893,261 Flinn ------------------- July 7, 1959 3,048,055 Borman et al ------------- Aug. 7, 1962

United States Patent Office 3,111-0;,198 3,110,198 TRANSMISSI,DN COINTROL SYSTEM August H. Borman, Jr., Detroit, Charles W. Cline, Lilonia, and Louis M. Fiteny, ABen Park, Mich., assignors to General Motors Corporation, Detroit, IVEch., a corpora5 tion of Delaware Ffled Sept. 20, 1960, Ser. No. 57,321 18 Claims. (Cl. 74-638) This invention relate@s to transmissions, and more par10 ticularly to a control system for controllin@. the drive ratio of a transniission of the step ratio type. An object of this invention to provide a control system for controuing the drive ratio of a step ratio transniission particularly adapted to accomplish chango of drive 15 ratio smoothly and with minimum torque react@'.on bumps. Another object of this invention is to provide i--Li a step ratio transmission having a fluid pressure applied and dluid pressure released brake, a control system for varying the timin@ of r,-I.-ase of the brake. 20 A further object oj-' this inN,--ntion is to provide in a transmission having a fluid pressure released brake an accumulator for controlling release of the braice and accumulator control valving for controlling the ac@'Lion of the accumulator. 25 An add;tional object of this invention is to provide in a transmission having a brake adapted to be released by fluid pressure an accumulator for controllin- release of the brake having a freely mo-vable pis+,on and control valving for controlli-@ig the stroke of the piston to vary the 30 tiniing of release of the brake. Another object is to provide in a transmission having a brak-e adapted to be released by iluid pressure and a hydrodynamic torque transmittin- unit adaptedto be filled with fluid, means for cortrolling the tiniing of release of the 3,5 brake including an accumulator and a pair of accumulator control valves wherein one of th-- control valves is controlled manually and the other of said control valves is controlled both manually and by pressure in the hydrodynamic torque transmittin- unit. 40 These and other objects and advantages of this inven, tion will be apparent from the following description and claims, taken in conjunction with the accompanying drawings in Nvhich: FIGURE 1 is a schematic drawing of a transniission 4,5 adapted to use the control system constituting this invention. FIGURE 2 is a block diaaram illustratin.- proper assembled relationship of F'IGURES 3, 4 and 5. FIGURE 3 is a schematic diagram of a pump and a 50 portion of the control valvin.- incorporated in the transmission control system. FIGURE 4 is a schem-atic diagram of a second portion of the control system includin- control valving, a band sei-vo and a front clutch accumulator. 55 FIGURE 5 is a schematic diagram of the remainder of th,- control system including control valving and a band release accumulator. Referring io FIGURE 1, the transmission, - illustrated schematically, has an engine driven power input shaft 60 10 connected to drive an impeller 12 of a twin turbine hydrodynainic torque transfer device 11 @which may be termed a hydraulic coupll:ng having turbines 13 and 14. A front planetary gear unit 15 includes a planet carrier 16 supporting a plurality of pinio-.q gears 17 in mesh with 65 a ring gear 18 and a sun gear 19. A rear -,ear unit 20 consists of a planet carrier 21 supporting a plurality of planet piinions 22 in m-.sh with a rin.- gear 23 and a sun, gear 24. First turbine 13 is directly connected to sun gear 24 by a shaft 25. Second turbine 14 is directly 70 connected to the planet carriers 16 and 21 by means of a hollow sieeve shaft 26. Planet carrier ZI is directly Paiented Nov. 12, 1963 2 connected to an output shaft 39 and turbine 14, catriet 16, carrier 21, and output shaft 39 all rotate as a unit. As hereafter mor,- @@lully explalied, turbine 14 in low or first gear dri7,re causes the coul@@in- 1-1 to function as a torque con-%,erter capable of multiplying torque. In second and third gear drive ratios, the hydrodynamic device 1-1 functions as ia fltiid coupling without torque multiplicat@.on. Sun -ear 19 is directly connected to ring gear Z3 for rotation there-,vith as a unit by means of a sleeve shaft 27. A front unit clutch 28 includes a set ev,' clutch discs 29 axially slidable on a clutch drum 30 driven by input shaft 10 and a set of clutch discs 31 slidable on ring gear 18 and rotatable -,with the ring a.ear. A piston 32 may receive -iquid pressure to engage the clutch. A cone bral.,e 33 is connected to ring gear 1.8 and mwy be en.-aged by a i9uid pressure responsive piston 3-4 for reverse drive. A brake band 35 may be appl-led to ring gear 23 to brake ring gear 23 apd sun gear 19 a,@ainst either forward or reverse rotation, by means of a fluid pressure controlled band s-.rvo 40, best sho-,vn in FIGURE 4. OPERATI-ON OF GENERAL ARRAiN,,-j-PI\IENT he transmission so far described af-fords neutral, three forward drive ratios, and reverse operatioi-1. For neutral operation, clutch 28, brake 33, and band 35 are ai-I released so that neither the front gear unit 15 nor the rear gear unit 20 has a reaction point and power cannot be transmitted to power output shaft 39. Fluid coupling 11 is of the type adapted to be alternately filled with and emptied of worldng fluid and is 'iHed vfith working flu;d in neutral condition of operatioi. Due to the lbad of the vehic-le on planet carriers 16 and 21 and upon turbine 14, the carriers and turbin.- -.1 4 will not rotate when the engine idles. Turbine 13 may rotate and drive sun gear 24 causin@ ring gear 23 and sun g@-ar 119 to spin. Ring gear 18 will likewise spin freely. For frst gear operation, coupling 11 is fuled with workin@ fluid and brake 35 is engaged. Upon acceleration of impeller 12 by speeding up the enoine, turbine 13 wffl initially begin to rotate sun gear 24 and brake band 35 will prevent rotation of ring gear 23t. At this mitial condition of operation, which may be termed "staH," the planet carrier 21 and turbine,14, Nvill either be he@ld against rotation or rotate slonvly forwardly due to the load of the vehicl@- applied to carrier 21 from shaft 39. Turbine 14 viil@l therefore re-direct fluid discharged from turbine 14 into iinpeller 12 such thaL the fluid entering impeller 12 tends to drive the impeller. Thus, at stall, the unit 11 functions as a hydrodynamic torque converter to multiply engine torqi-ie. Shaft 39 is driven at the torque multiplication of unit 11 and the torque multiplication of gear unit 20. As the output shaft 39 speeds up, tlirbine 14 also speeds up and the torque multiplication through the unit 11 diminishes with increase in speed of rotation of turbine 14 vvhile the torqle multiplication of gear unit 20 remains constant. Unit 11 may reach a condition of op--ration wherein n-linimum torque muiltipl-ication is provided by unit 11 in first gear drive, but the torque multiplication of unit 11 will never drop to zero. Since turb-@'ne 14 can never attain the speed of rotation of impeller 12 in first .@ear drive, turbine 14 will act as a forwardly rotating reaction mp-mber in first a.ear drive. For second speed drive couplin.- uni-t IIL is emptied of working ffuid, front clutch 28 is enga,-ed and brake band 35 is applied. Ring gear 18 is driven at engine si3eed while brake band 35 provents rotation of sun gear, 19 and rin.- g--ar 23 either fornvardly or in reverse. Planet carrier @16 of front gear unit 15 drives outpat shaf-t 39 at the reduction ratio of front gear unit 15. Since coupling 11 is empty, there is no power input to rear gear unit 21,1. In second speed drive ratio no hydrodynamic losses occiir since fie drive is entirely mechanical.

3 For direct drive, or tfiird gear dr-ije ratio, front clutch 28 is en.-aged, brake 35 is released, and coupling 11 is f .ill@-d with ffuid. Drive is transmitted through clutch 23 to ring gear 18, tlirough turbine 13 to su--@i gear 24, and through turbine 14 to planet carriers 16 and 21. At this time turbines 13 and 14 will rotate at substantially the speed of rotation of impeller 12. It will be apparent t-herefore that ring -ear 18 and planet carrier 16 of the front gear unit 15 will each b-- driven substantially at engine speed and that the @front gear unit viill be locked up in direct drive. Also, sir..-c sun gear 24 a@id pla.,ict carrier 21 of the rear gear unit 20 ar-- each dr-.ven substantially at e@i,-ine speed, the rear gear uriit 20 will be locked up in d-irect drive. To obtain reverse operation, coupeng 11 is filled with fluid and reverse cone brake 33 is en.-aged. Ring gear 18 of front gear upit 15 is held a.-ainst rotation. Turbine 13 drives sun gear 24 forwardly in the direction of rotation of impeller 12. Due to the vehicle load on planet cariiers 21 and 16, the carriers tend to remain stationary. Rin,- -ear 23 and sun gear 19 therefore rotat-- reversely since brake 35 is released. As a consequence, this backward rotation of sun gear 19 will cause carrier 16 to rotate baclcwards at redticed spe.-d. Tiirbine 14 also i_mparts reverse rotation to shaft 26. Load shaft 39 will therefore be driven in reduction drive through gear unit 15 and will have additioral reverse torqiie applied thereto by turbine 14. CONTROL SYSTEM T@he various clutches, brakes, and t'iie coup'iin,@ unit 11 ar.- all operated in th-- proper sequence by 'che hydraulic control system shon,;n schematically in the dravvin.-s. Each drive establishin.- device or servo may be of known constrl,ction employing a piston which by fluid pressure sup,plied to the servo is moved to its en.-a,- ed position. Fluid pressure for the control system is supplied by a pum,p 50, sho,,vn in FIGUPE 3, of the variable capacity type similar in function and detail to that sho@wn in the Herndon patent, U.S. Patent No. 2,875,699. Pump 50 has a slide member 51 adapted to slide up and down, as viewed, in a guideway in the pump body. The volume of flui-d disc@haraed depends upon the position ol' slide 51 in its guide. A suring 52 biases slide 51 to its maximum capacity position. Pump 50 is driven by power input shaft 10 so as to commence operation as soon as the engine is started. Fluid is drawn from a surtion passage 53 and discharged to a main supply passage 400. Pressiire Regilator Valve For controllin.- the pressure dischar,-ed by PUMP 50 i@qto main supply line 4110, a pressure regulator valve 55 is slidable in a bore in a valve body and is furnished with pressure fluid from main supply line 400. Valve 55 is provided witn a plurality of sparedlands 56, 57, 58, 59 ;and .60 and is biased upwardly by a spring 61 towards its maximum against the pressure of fluid delivered by passage 400 to the top end of valve 55. A passage 62 ext,ends from the upper end of valv-- 55 through the center thereof and communicates with a cross passage 63 in the val-ve between lands 58 and 59. In the position shown pressure fliiid from passage 400 acting on the upper fac,,' of land 56 will urge valve 55 downwardly a.@a;nst sp,.ring 61 and I will be transferred by passages 62 and 63 to la passa,@e 64 Nvhich communicates with the bottom Slide 51. A passage 65 communicating with the, top of slide 51 is blocked off by land 59. The pressure fluid at the bottom of slide 51 plus spring 61 ur-,e slide 51 upwardly towards its maxi-mum capacity position. As the fluid pressure in palssage 400 increases, valve 55 will move downwardly so that land 58 will perrnit flow of ffuid from passage, 64 to exhaust port 67 and to align passage 63 with passage 05. Pressure acting on the top of slide 51 wil-I @urge it downwardly to reduce the volume of the pump (i@tPut. Sprin.@ 61 is effective to cause valve 55 to mai,ntain a pressure ot 90 pounds in pass?@ge 3,110,198 4 Iii the fore,-oing manncr, pressure regulator valve 55 will reciprocate belween the above-mentioned positions so as to supply fluid pressure either to the L-ottom side of the slide 51 througii passa,@e 64 or the top side of slide 51 through passage 65. Conseqljently, slide 51 will be positioned so that the volume of fluid pumped is sufficient to produce th-. pressure determined by the action of pressure regulator valve 55. lo MANUAL VA-LVE Main pressure supply passage 400 extends to a manlally ;op--rated drive range selector valve 70 shown in FIGURE 4, having spaced lands 71, 72, :and 73. A pair of flanges 74 and 75 are provided for receiving an actuating 15 pin 76 which may be actuated by suitable linkage (n,ot sho,@vn) operable by the vehicle driver to position valve 70 to select Park, Neutral, Drive Range, Intermediate Rangp-, Low Range, or Reverse conditions iof operation. Valve body 77 is provided with p s 78, 79, 80, 81, 82, 9.0 93, 84 and 85. Ports 84 and 85 are exhaust ports and the remainder of tho ports connect to fluid passages as hereafter more fully explained. THRO=EVALVE 25 Ma-n pr-Issure si,@pply -passa,@e 401"y extends to a throltle val@ve 90 composed of lands 91, 92 and 93 slidable 'm a bore in a valve bcdy 9@', see FIG. 4. A second vat-,,e 95, wmeh may be termed a pa@-t throttle valve, having spaced lands 96 and 97 is slidable in valve body 94. An exten30 sion stem 93 of valve 95 extends outwardly through a seal 99 and is adapted to be acted upon by an actuatiig pin 100 connected to the vehicle accelerator pedal (not shown) by a suitable linka.-e (not shovm). 'fhe arrangement is such that stem 93 wiR be moved to the left into body 94. 35 in resdon.-e to dep.-ession of the accelerator pedal to increas@ the supply of fuel to t-he engine. A spring 101 seats on land 9il of val-ve 90 and @upon land 96 of valve 1,5. , !Pjla seats upon valve body 94 and A secotid sp.-in@ land 96 of valve 95. A U-shaped cali-brating - screw,102 40 bears against the end of land 93 and against a calibrating screw 102a in the end of valve body 94. Parts 103, 104 @and 104a are associatp-d with valve 90. Port 103 connects to line pressure supply passa@ge 40,9. Port 104 connects to a throttle valve pressure delivery passage 407. Port 45 104a is an exhatist port. Bore 94 has por-ts,105, 106, 107 and 108 therein associatcd v/ith piart throttle valve 9@5. Port 105 is supplied @with @quid press,,ire ' rom throttle valve pressure delivery passage 407. It will be noted that land 97 is of greater 50 diameter than stem 93. Throttle valve pressure ac;,dng on land 97 will apply a @thrust to valve 95 tending to move the valve to the le;ft to compress spring 101. Port 106 connects to a line pressure supply passqge 401- controllect by matiual valve 70. Port 107 connects to a band @apply 55 passa,,,e 413. Port 108 is an exhaust port. In o-Deration, assuming the vehicle accelerator pedal is relaxed, -@prin,,@ 101 will position throttle valve 90 to block off port 103 from port 104 and spring 102 wiR positio@l valve 90 to cgri-iect port 104 to ex-haust p--,rt l@4a. 60 SPring 101 NviH positi<)n valve 95 to block off port 106 from 107. As the accelerator pedal is depressed, stem 98 is moved to the left to apply a load to sptin@g 10@l, thereby moviiig valve 90 to the le-ft to co@nnect port 103 to port 104 to deliverp@ressure to @throttle valve pressure delivery 65 passage 407. Pressure from passage 407 is adn-iiitted to a chamber 110 at the end of land 93, this pressure -bein,,@ efiective to move valve 90 to the right to cause land 92 to block off p@ort 104 from port 103. In the event that the accelerator pedal is relaxed, Pressure in chamber 1,10 70 Will MOVE Valve 90 to connect port 104 to exhaust port 104a. The pressure m passaae 407 therefore varies and increases as the accelerator pedal is depressed. Throttle valve 90 is a pressure rneterin@g valve adapted to deliver a variable pressure which increases with engine torque 75 demand.

1. . I 1 3 ,110,198 6 in the initial sta,-es of operation of valve 90, land 96 .4c,f valve 95 bloels off port 106 from port 107. Ho-@vever, after a certain -predetemh-ied pressiire is delinered to throtde valve pressure delivery passage 407, this pressure acting on land 97 of valve 95 will move valve 95 to the 5 left to conne-,t port 106 to port 107 for purposes hereafter more fully explained. DETENT VALVE A detent valve 112 shown in FIG. 5 having lands 113, 10 114, fl!5 @and 116, is acted upon by a piti 117 acting through a collar 118. Pin 118 is controlled by a suilable linkage (not shown) actuated by the vehicle accelerator pedal not enown. Five ports 119, 120, 121, 122 and 123 are associated with dete-nt valve 112. Ports 119 and 120 15 connect to throttle valve pressure passage 407. Port 121 connects to a part throttle pressure delivery passage 426. Port 122 connects to a detent pressure delivery passage 423, and port 123 connects to exhaust. A sprin.- 124 acting on land 113 normally positions detent valve 112 20 to biock off port 120 from ports 121 and 122. In opcration, as the accelerator pedal is @depress,-d to provide a predeternuned degree -of carburetor throttle valve openin,-, land,113 ivill permit flow of throttle valve presslire fluid from passa-2e 407 to passage 426 through 25 ports 120 and 121. At this part throttle opening of the carburetor throttle valve, the throttle valve pressure in passa.-e 407 wifl be substaitial, but not full line pressure. Further depression of the accelerator pedal W'ffl move valve 112 to adnlit pressure from passage 407 to a detent 5( passa,-e 428 thron,-h ports 120 and 122. At this time t@,e Lirottle valve pressure supplied to passage 407 by thrr,ttle valve 90 -,villbefLil.1 line pressure and the. pressure delive.-ed to passages 426 and 428 by detent valve 112 will @likewise be full line pressure. 35 The control functions of the throttle valve pressiire in passa.-e 407, in passa-,e 426 and @in passage 428 wfll hereafter be more fully explained. LINE PRESSURE RELIEF VALVE 40 Main line pressure supply passage 400 extends to a relief valve 125 shown in FIGURE 3 which comprises a ball 126 seated on a seat 127 by a spring 128, the bore of the valve havin.@ an exhaust port @129. Spring 128 se-,its on a pin 130 and ball 126. Valve 125 is pro@,,ided 45 as a safety f@- alure to prevent excess pressures in the system as might occur in the event that either slide 51 of purr,p 50 or the pressure regulator valve 55 should become stuck in an improper position. Valve 125 also pre'vents e.-,cess system pressure when t@e oil is cold. 50 GOVERNOR Main pressure supply passage 400 extends to a bydrai.ilic tgovernor 135 shown in FIGURE 4 arran.-ed to be driven at speeds prc@,cortional to vehicle speed, for example, by po-,@ier deliverv shaft 39. Governor 135 55 may be of the type shown in the Borman et al. patent, U.S. Patent No. 3,048,055. Governor 135 develops two sta,-es of pressure determined by the speed at v,,hich the govei,nor is rotated. A first stage termed G-1 pressure 60 is dehvered to a passage 229 and a second stage termed G-2 pressure is d.-li@iered to a passa.-e 229. These hvo stages are deveioped simultaneously, the G-2 pressure b,-ing developed at a d:lfferent rate than G-11 pressure. Both G-1 and G-2 pressure vary with vehicle speed. 65 Since the operation of the govemor is fully described in the above referred to Borman applica'Lion, further detailed desenption is deemed Lnnecessary herell. The G-1 pressure in passage 228 and G-2 pressure in passage 229 are used for ciantrol purposes as hereafter more 70 f-ally ex@plained. 2-3 SHMT VALVE Main line pressure supply passage 400 extends to a second to third igear shift valve assembly indicated igenerally at 140 in FIGURE 5 and us.@d to control shi-ft of 75 drive ratio b@etween second and tlurd dear. Assemlyly 140 includes a govemor valve 141, a shift valve 142 and a modulator valve 143. Governor valve 141 includes lands 144, 145, 146 and 147, and ports 143, 1491, 150, 151, 152, 153, 154 and 155. A plu,- 156a in the epd o'L the valire bore is connected to exhaust by exhaust port 157. Port jlsg connects to G-il governor pressure delivery passage 228 to admit G-1 governor pressure to the end oi' land 144. Port 149 co-nneels to a third gear cDuplin@.@ feed passage 410. Port 150 connects to line pressure supply passage 400. Port 151 connects to a first gear pressure passage 417. Port 152 -connects to a first @and third igear pressure passage 418. Port 153 connects to line pressure siipply passage 400. Ports 154 and 155 connect to exhaust. It will be noted that line pressure supply passage 400 is continuously conducted to third gear coupliig feed passage 410 through a @restriction 156. When valve 141 is in its downshift. position restriction 156 is effective -and when valve 141 is upshi,'ted restriction 156 is by-passed through ports 150 and @149. Shift valve 142 is provided with three spaced lands 153, 159, 160, the land 160 ,being of greater diarneter than lands 15S and 159. Four ports 161, 162@ 163 and 164 are associated with shift valve 142. Port 161 connects to throttle valve pressure supply passage 407. Port 162 connects to a sluft throttcle valve passage 16,5. Por-t 163 conn,- cts to part thrbttle pressure delivery passa.-e 426. Port 164 -connects to G-2 govemor pressure delivery passa.-C 229. Modulation valve 143 is provided with spaced lands 166 and 167 and a stem extension 168 adapted to at certain times contact the end of land 160. Land 167 is of greater diameter than land 166. Four ports 169, 170, 171 and 172 are associated -,vitii modulator valve 143. Port 169 connects to passage 165. Ports 170 and 172 connect to a modulated throttle valve pressure passage 173. Port 171 connects to a passage 429. A spring 174 seats on land 166;and on land 160 to yieldably bias the modulator valve 143 to the left and sbift valve 142 and govemor valve 141 to the right or to their downshift position. PRESSURE BOOST VALVE Line pressure supply passage 400 extends to a pressure boost valve 180 shown in FIG 5 having four spaced lands 181, 182, 183 and 184. 'Land 184 is of greater diameter than lands 181 through 183. A pin 185 forms a seat for a Plug 186. A spring 187 seated on plug 186 yieldably biases valve 180 outwardly to the left. Seven ports 188, 139, 190, 191, 192, 193 and 194 are asSGeiated with valve 180. Port 188 connects to a drive pressure supply passage 401, toadniit line pressure to the end of land ][81. Port 189 connects to a line drop feed or pressure supply passage 405. Port 190 connects to a line &op signal passa,-e 406. Port 191 connects to main line pressure supply passage 400. Port 192 connects to a line boost pressure delivery passa,@e 416. Port 193 connects to a reverse pressure supply passage 404. Port 194 c-onnects to a front clutch pressure supply passage 427. Line drop feed passage 405 will be p@-ovided Nvith line pressure through manual valve 70 when valve 70 is positioned to select Park, Ne tral, Drive Range and Reverse conditions u of operation. When valve 70 is positioned to select intermediate range or low range condition of operation, passage 405 will be bloOKed off by land 71 of valve 70 from@ line pressure supply passage 400, and will be connected to exhaust through port 84 of valve 70. Line pressure from pressure supply Ene 400 will be admitted to drive passage 401 when valve 70 is positioned to select drive range, intermediate range or loiv range operation. When valve 70 is positioned for reverse operation, line pressure from passaae 400 is admitted to lite drop feed passage 405 and to reverse pressure supply passage 404. Line boost passa.ae 416 connects to a port 299 beneath a piston 300, see FICR. 3, on which spring:61 of line'pres-

7 sure regulator valve seats. When valve 180 is moved to the right-hand position against the action of sprin.@ 187 by line presslire adnlitted to the end of land 181, valve 180 admits line pressure from passage 400 to line boost pressure passage 416 throuah ports 191 and 192. This pressure acting on piston 300 will cause the pressure reoulator valve 55 to boost the line pressure to a maxinilim of 164 pounds. COUPLING TIMING VALVE In the same bore Nvlth pressure boost valve 180 is a coupling dmin.- valve 200 having six spaced lands 201, 202, 203, 204, 205 and 206. Ten ports 207, 208, 209, Z10, 211, 2.12, 213, 214, Z15 and 216 are associated with valve 200. Port 207 connects to a second to third gear pressure passage 423. Port 208 connects @Lo a band releasapassage4l4. Port2O9isanexhaustport. Port2@'Oconnects to a coupling feed passage 411. Port 211 connects tlo a third gear coupling feed passa.-e 410. Port 212 connects to third gear accumulator exhaust passage 420. Port 213 is an exhaust port. Port 2.14 connects to coupling signal pressure passage 409. Port 215 connects to line pressure supply passage 400. Port Z16 connects to first and twrd gear coupling fe-@d passage 418. A spring 217 seated on a plu@ 213 and on land 206 yieldably biases valve 200 to the left such that land 201 will contact pin 185. Land 202 is of lesser diamet-,r than land Y'03 so that coupling feed passage 411 will be connected to exhaust port 209 Nvhen valve 200 is moved to its right-hand position wherein spring 217 is compressed. COUPLING FEED LIMIT VAI@:VE Main line pressure supply passage 400 finally extends to a coupling feed limit valve 220 (see F-IG. 3) hwiing spaced lands 221 and 222 and biased to its upper posit - ion by a strong sprin- 223. Four ports 224, 225, 226 and 727 are associated with valve 220. Port 224 admits fluid pressure from fluid coupling signal passa-e 409 to the end of land 221. Port 225 con-@iects to main line pressure supply passage 400. Port 226 connects tO a coupling feed passa,@e 412. Port 227 connects to exhaust. In the event that fluid pressure in coupling si.-nal passage 409 is greater than a predeterm@.ned min,.niurn pressure, couplin.- feed limit valve 220 wiil compress spring tO admit line pressure from main line pressure supply passage 400 to couplin- feed passage 412. In the event that pres sure in coupling signal passage 409 is less -than said predetermined pressure, valve 220 will block off passage 40@B frbm coiipling feed passa@e 412. Valve 220 provide fast fill of couplin.- s @a 11 through passage 412 at heavy throttle opening in shifting from second to third @ear drive ratio. 1-2 ST.-UFT VALNTE A ast to second shi ft valve asserqb'ly 230 (see FIG. 5) includes a governor valve 231, a shift valve 232 aid a modulator valve 233. Governor valve 231 includes four spaced lands 234, 235, 236 and 237, the land 234 being of grea-ter diameter than land 235. Eight ports 233, 239, 240, 241, 247, 243, 244 and 245 are associated with governor valve 231. A plug 246 blocks off the end of the valve bore. Port 238 ad@-iits G-1 governor pressure from passage 428 to the end of land 234. Port 239 connects to low range pressure supply passage 493 adapted to be supplied with line pressure @vhen manual valve 70 is positioned to select IoNv ran,,e operation. Port 240 connects to a second to first gear signal pasgage 4-.15. Por-t 241 connects to a front clutch apply passa,@e 427. Port 242 connects to drive range pressure passa.ac 401. Port 243 connects to a passage. 417 connected to port 151 of governor valvll 141. Port 244 is connected to an exhaust port 245 by a passage 247. First to seegnd gear shift valve 232 is provided v.,,ith spaced lands 250, 251 and 252 and a series of ports Z53, 254, 255, 256 an . d 257. Port 253 connects to second to third gear pressure passage 423. Port 254 connects to I a third gear band release passage 422. Port 255 connec,s to tlu-ottle valve pressure deliveiy passage 407. Port 256 connects to a throttle valve pressure d@livery passage 424. Port 257 connects to a detent Ene pressure delivery passage 428. Modulator valve 233 includes lands 258 and 259 ' the land 259 being of greater diameter than land 253, and four ports 260, 261, 262 and 263. Port 260 connects 10 to a pressure supply passag-- 425. Port 261 is connected to port 263 by a moduiat-ld pressure delivery passage 264. Port 262 co-@inects to a reverse pressure su_Lply passage 40-,I. A plug 265 blocks off the end of the valve bore. A first s'Drin,@ 266 nornially urges valves 232 and 231 to 15 their left-hand or do@,vr@shift position. A second spring 267 seated upo-ii land 259 and la,-id 252 normally biases niodulator valve 233 to the right. A ball check valve 268 is located at the jupcture of throttle valve pressure delivery passage 424, low range pressure supply passage 20 403, and passag-- 425. Nlith manual valve 70 positioned for low range operation line pressure from passa,-e 403 will flow past ball check'valve 263 to passa,@e 425. V@ith the maniial valve positiored for any other drive range cotiditior. of oderation, passage 403 will be connected to 25 exhaust. V,/ith manual valve 70 posit;O-.ied -'Lor any other drive range condition of operatio-@i ot.@er than low range, and with shift valve 232 i-ti its downshift position, throttle valve pressure Lrom passage 407 will flow through ports 255 and 256 of va'ive 232 to passage 424, past ball check 30 valve 263 to passage 425. Ball check valve 268 will theii blo-,k off passage 403 to permit exhaust o@F throttle valve t)ressure through the manual valve 70. ThrotL'e valve pressure acting on the end of land 253 v,,ill move modulator valve 233 to the left, compressing 35 sprin- 267 and permit a modulated throttle valve pressure to enter the chariber containii- spring 267 between valves 232 and 233. This modulated pressure will flow through passage 264 to the spring chamb@-r. Due to the action of q-pring 267 the pressure in the spring chamber 40 will be proport,'@Onal to but Iess than the throttle valale pressure ii passa-.e 425. Th-is mod'alat,-d press-Lire acting or. the er@d of land 252 tends to maintaiii the shift valve 232 and governor valve 231 in their 1-@ft-hand or downSL'ift position. 45 2-1 DOWNSHIFT VALVE It ,vill be noted that front clutch pressure apply passage 427 is connected to exhwdst by a second to first gear signal passage 415 ,vhen -,overnor valve 231 is in its downshift positioti. Front clutch apply passage 427 will be con5o nected to @econd to first gear signal pass-.,@e 415 by way of ports 241 and 240 of the first to second gear shift valve when the assembly is downshifted. Passage 415 is continuously connected to exhaust through a fixed restric55 Lion 269 (see FIG. 4). A second to first do,,vrshift valve 270 shown in FIG. 4 has spaced lands 271 aiid 272, the valve being biased to -its left-hand position by a spring 273 se-,ited i@ron a pin 274 and the end of lalid 272. A plug 275 blocks off the end of the valve bore. I Three ports 276, 277 and 278 are associated with valve 270. 60 Ports 276 and 277 connect to passa,@e 415. Port 273 is an exhaust port. Valve 270 is effective during a second to first - forced downshii@t to provide a means for 'Mitial rap:i'dearreduct;on of clut@-h pressure. 'vvhen the pressure in signal passage 415 is greater than a predeterrr@ined 65 pressure, for example 35 pou-ids, pressure entering port 276 wili. move valve 270 to the right agaiiist s@t),ring 273 to coniiect port 277 to exhaust port 278. When the pressure in passage 415 drops to 35 pounds, spring 273 will position land 272 to block off port 273 from port 277. 70 FRONT CLUTCH EXHAUST VALVE Posit;o-ned in the same bore with second to first gear dowpshift valve 270 is a j'ront clutch exhaust valve 280 having lands 231 and 232 and biased to its righthand 75 position by a sprilig 233 seated upon plil 27,4 and land

@81. F6ur ports 284, 285, 286 and @81 a're associated m,ith valve 280. Port 234 connects to coupling feed passa,@e 411. Port 285 cor,.:iects to second to first @ear si-,- -al pasage 415. Ports 286 and 287 are exha,,ist ports. Valve 280 is controlled by coupling f,-ed pressure to connect passage 415 to exha-tist when the coupling fced pressure rises to a point where the couplin.- is capable of transmitting full engine torqae. When pressure in couplin.- feed passa.ae 411 is sufficiently high, this pressure acting on the end of land 282 ivill move valve 280 to the left against the action of sprin.- 233 to connect passage 415 to exbaust by way of ports 285 and 236. Valves 270 and 280 cooperate to provide a two stage exhaust of front clutch apply passa.-e 427 when making a forced or heavy,throttle downshift from second to first gear. PRE-QSURE D-ROP "VTALVE A pressure drop valve 290 shown in FIG. 4 has spaced 1--Pds 291 and 2@2 and is biased to its left-hand position by a spring 293 seated upon a pin 294 and land 292. Four ports 295, 296, 297 and 293 are associated with valve 290. Port 295 adm;@ts throttle valve pressure from passa.-e 407 to the end of the valve bore. Port 296 connects to a line drop signal passage 406. Port 297 connects to a line drop pressure passage 408, and port 298 is an exhaust port. In operation, valve 290 delivers presure to passage 403 -,vh:ch varies inversely with throttle valve pressure in passage 407. When the throttle valve pressure in passage 407 is low, or zero as -,vith closed throttle with the accelerator pedal re'laxed, spring 293 - @vill position valve 290 to connect ports 296 and 297 and block off exhaust port 298. As the throttle valve pressure in Dassagf-- 407 increases in response to depression of the accelerator pedal, valve 290 will move to the right to crack open exhaust port 293 to reduce the pressure in passac.e 408 at full throttle opening, land 291 will block off port 296 and port 297 Nvill connect port 298 to exhaust. As her.-tofore stated, land 57 of pressure regulator valve 55 is of greater diameter than land 56. The pressure supplied to valve 55 by passage 408 enters between lands 56 and 57 and exerts a downward thrust on valve 55 against spring 61 to reduce the line pressure supplied by valve 55. When passage 408 is exhausted spring 61 will maintain a line pressure of 95 pounds. As the pressure in passa-,e 403 increases, line pressure in passage 400 will progressively droi) to a minimum of 66 pounds when the accelerator pedai is coinpletcly relaxed. COUPLING EXHAUST VALVE A coupling exhaust valve 305 shown in FIGURE 3 comprises a head 306 on a guide ster@i 307. A sprin- 308 yieldably biases valve 305 off ol' a valve seat 309 to permit the fluid coiipling to be exhausted througja an exhaust port 310. When flu;d pressure from coupling s@gnal passage 409 is admitted to head 306 through a port @ll, valve 305 moves downwardly against sprin.- 303 to seat upon valve seat 309 to block off exhaust port 310. FRONT CLUTCH ACCUMULATOR A front clutch accumulator 315 shown in FIGURE 4 is connected to the front clutch apply passage 427 by way of a po,-t 317 in accumulator housing 316. A guide pin 318 flxed to housing 316 slidably supports pistons 319 and 320 thereon. Springs 321 and 322 yieldably bias pistons 319 and 320, respectively, into contact with each other. Pistons 319 and 320 are of different diameter and port 317 admits front clutch ELi)p'IY pressure to a chamber 323 between the pistons. A chamber 324 beneath piston 320 is adapted to receive a var.,able pressure from a compensator valve pressure delivery passage 425 through a port 325. It will be apparent that the accumulator pistons will move to compress st)rings 321 and 322 in response to pressure in chamber 323. Piston 319 is responsive solely to the rate of spring 321 and will stroke before piston 320 @ttbkes. Piston 320 is responsive not only to the rate of spring 322 but also to coir@pensator pressure. admitted to chambers 324. The accumulator, which is used to control the rate of engagement of the front clutch provides a two stage action for smooth clutch engage@ ment and due to the effect of compensator pressure in charr@ber 324. calibrates the clutch engagement very closely to the torque output of the engine. As hereafter more fully explained, compensator pressure delivered to cham10 ber 324 varies closely with changes in engine d--veloped torque so as to calibrate the clutch engagement to engine torque oulput. Compensator pressure is admitted to chamber 324 through a port 325. COMPENSATOR VALVE 1,5 A compensator valve assembly 326 includes a valve 327 and a pair of plungers 328 and 329. Plun-,er 329 is yieldably biased against a pin 330 to block off an exhaust port 332 by a spring 331. Valve 327 is provided with 20 pa,ed lands 333, 334 and 335 and with ports 336, 337, 338, 339 and 340. Port 338 admits throttle valve pressure from throttle valve pressure passage 407 to the space between land 333 and the end of plug 329. When the throttle valve pressure reaches a predetermined value, 25 plug 329 Nvi'll connect port 338 to port 332 to Iiinit the maximum throttle valve pressure effective on the end of land 333. Port 336 connects to drive range pressure supply passage 401. Port 337 connects to compensator pressure delivery passage 425. Ports 339 and 340 connect 30 to exhaust. A sprin- 341 yieldably biases valve 327 to its ri.-ht-hand position wherein port 336 is connected to port 337. Plug 328 is provided with spaced lands 342 and 343, the land 343 being of greater diameter than land 342. A fixed plug 344 closes off the end of the valve bore. 35 Comp--nsator pessure from passage 425 is admitted to the end of land 343 through a pc)rt 345 and to the valve bore between lands 342 and 335 through a port 346. A spring 347 and compensator pressure acting on the end of land 342 oppose movement of plug 328 to the left. 40 Port 348 is an exhaust port ' The compensator pressure in compensator pressure passa.-e 425 is controlled by throttle valve pressure which increases with demand for engine torque but which is not proportional to actual engine delivered torque. The com45 pensator pressure is calibrated to vary wilh changes in en,-ine delivered torque and is arrived at in two stages. In the initial stage, valve 327 does the regulating and plunger 328 is of no effect. Initially, spri-iig 341 and tlirottle valve prcssure acting on the end of land 333 will 50 posicon valve 327 to connect port 336 to port 337 to permit oil flow to compensator pressure passage 425. Pressure from passage 425 is admitted through port 346 and will act in assistance to spring 347 to move plunger 328 to the right and will act on land 335 to rnove valve 327 55 to the 'left. Land 335 is of greater diameter than land 333 so that valve 327 will be moved to the left to block off port 336 from port 337. Pressure in passage 425 varies as the throttle valve pressure varies but at a different rate, the pressure changes in passage 425 being calibrated to 60 change with variation in engine delivered torque. As the pressure in passage 425 reaches a predet--rmined pressure, plunger 328 is rnoved to the left against spring 347 and applies an additional force to valve 327 tending to move valve 327 to the left to initiate the second stage 65 action. The compensator pressure curve developed by valve 327 changes with changes in engine delivered torque as distin,-uished from torque demand. In operation of the front clutch accumulator 315 Nvhen line pressure is admitted to front clutch apply passage 427, 70 piston 319 will initially move against spring 321 as the front c'.Utch discs come into contact. The compensator pressure in chamber 324 varies closely with changes in engine delivered torque. The pressure build up in passage 427 and acting on the front clutch is therefore calibrated 75 to vary closely with changes in engine delivered torque to

provide smooth clutch engagement and sufficient capacity to ha@-idle the torque load. At light throttle and light torque clutch engagement will b.- slower than at heavy en,-ine delivered torque. It will be apparent that accumulator 315 in combination with compensator valve 327 varies the rate of clutch engagement in accordance with changes in engine delivered torque as distinguished from torque demand. REVERSE BLOC-KER A reverse blocl@-er 350 shown in FIG. 4 is supplied w;tii G-1 governor pressure from governor pressure d,-Iivery passage 228. Blocker 350 comprises a piston 351 slidable in a hoi-ising 352 and is provided w-ith plungcr 353 adapted to extend out of housin.- 352 into the path of linkage (not sho,@vn) connected to iranual valve 70 to prev@ent valv,- 70 from bei-@ig placed in reverse vihen the vehicle speed is higher tla@i a predelcrjrdned spe-@d. A spring 354 actin.- on piston 351 opposes movem-@nt of plunger 353 out of tle hotisin.-. Govp-rnori)ressure actip,,- on piston '-151 will force plun,-er 353 outwardly for its blocking ar-tion Nvhen the vehicle --.pced exceeds the predeterinined speed, f@ar exan-iple eigh@L n-i,:Ies per hoiir. BAND SERVO A brale band servo 40 shown in l-'IG. 4 is adapted to control the en,.-,agement and release of brake ba-ad 35. Servo 40 is provided with a housin-, 353 having an actuating rod 356 ex'Lending therethrough the rod having a spring seat 357 fixed thereto for movement therevvith. A sprin.- 357a, seated upon housing 355 and seat 357, yieldably urges rod 356 to its band release position. A piston 353 is slidably supported on rod 356, there bein@ '., a spring 359 s-,ated upon seat 357 and piston 358. A pair of fluid pressi-ire receiv;la-, chambers 360 and 361 are disposed on oppos;.te sides of piston 358. A restricted passage 362 through piston 358 connects chamber 360 to chawber 36-o-. A passa.-e 363 in rod 356 is connected to a cross passage 364 in rod 356, the passage 364 being i,.neovered by piston 353 when sprina 359 is fully extended. Flui(i pressure may be admitted to chamber 360 from band apply p2,ssage 413 to force rod 356 out,@vardly to engage the band. As piston 353 moves to compress spring 359, passn-ge 364 will be blocked off by piston 353. Fluid pressure may be admitted to chamber 361 to release fne band, from a band release passage 414. Restricted passages 362 and passa.-Cs 363 and 364 delay the inii-lal rate of fluid pressure build up in chamber 360 when fluid pressure is first admitted to chamber 360 to engage the band. Spring 359 additional'iy cushions the band engagement to reduce the shock. These features provide smoo band application by servo 40. The rod 356 may actuate suita'i)le linkage mechanism (not shown) to engage the brake band. BAND RELEASE VALVE A band release timing valve 365 shown in FIG. 5 is provided with sdaced lands 366, 367:and 368,;and the land .366 -being oi' -,maller diam--ter than lands 367 and 368. Five ports 369, 370, 371, 372 and 373 @are jassociated with valve 365. Por-t 369 admits pressure from colpling feed passa.ae 411 to the end of land 366 ' Port 370 admits pressure fror.,i compensator pressure passage 425 to th-, end of land 367. Port 371 conn--cts to a passage 418. Port 372 connecls to a passage 419. Port 373 connects to a passa,-e 420. A spring 374 yieldably biases valve 365 to its ri.-ht-hand position. Valve 365 is controlled by coupling fe--d pressure @and compensator pressi-ire to control the -action of a band release -accumulator 390 as hereafter more fury explained LOW THROTRLE E.KH-A-UST VALVE A low throttle exhaust valve 375 is disposed in the swne bore W;th band -release valve 365. Valve 375 includes spaced lands 376 and 377, there bein.- six i)orts 373, 379, 12 380, 381, o'82 @and 383 associated with the valve. A plu.,384 blocks oif the end of the valve bore. A spring 385 seated upon ja spring seat 386 @and land 377 yieldably biases valve 375 to its left-hand position. Port 378 is an exhaust port. Por-t 379 connects to second to first ge@ar signal passa.-C 415. Port 380 connects to,a passage 419. Port 381 connects toa third gear b,and release accumulator passage 4ZI. Port 382 connects to passage 418. Port 383 @admits throttle valve pressure from passage 407 to the 10 end of land 376. At closed throttle, spring 385 will position valve 375 to connect second to first gear signal passage 415 to exhaust by ivay of ports 379,and 378, @and to connect passaac 421 to passage 418 by way of ports 381 and 382. At heavy throttle, throttle valve pressure will 15 b@- effective to position valve 375 to connect passa,-e 421 to passa-,e 419 throu.-h ports 3SI and 380. At heavy thro,tic iihen throttle valve press-,ire exceeds 25 poands, la--d 377 ivill block oT port 379 to prevent exhaust o pressure through port 378. 20 BAND RELEASE ACCUMULATOR A baid rel.case accumi-,Iatot 390 compri,.zes a free piston 391 positioned for movement ina cylinder 392. A plug 393 blocks off one end of cylinder 392. Cylinder 392 is 25 connected to passage 421 @at one end of the cylinder by a port 394. Cylinder 392 is connected to a passa@e 414 at the opposite end of the cylinder by a port 395. BALL CHECK VALVES In additioi to the ball chec"- valve 268 heretofore de30 scribed, the control system includes four one-way ball check valves 396, 397, 398,and 399. Referrin@ to FIGURE 4, a resistrir-tion 13-t is disposed in drive range passa.-e 40jl;at the juncture of drive rapge 101 and band,apply passa.-c 413. Restriction 131 3 D- passag-. . p,-rmits continuous restricted fluid flow from drive range passage 401 to band apply passage 413. In the event that fluid is attempting to flow from passage 401 to passage 413, ball check valve 396 will,be seated. In the event that 40 iquid is attempting to flow in the opposite direction, baH check valve 396 @will unseat to by-pass restrielion 131. Referring to FIGUIZE 5, ;a one-way b-,tll check valve 39@7 is shown at the juncture of third gear band release passage 422 and band release accumulator passaae 421. 45 In the event that fluid tends to flowfrom passage 422 to passage 421, valve 397 will seat. In the event fluidtends to flow in the opposite -direction, valve 397 wiR unseat. Ball check valve 398 wiU seat to Drevent fluid ffow from third gear band release passige 422 to passage 419 but will 50 p.-rmit fluid flow in the opposite direction. B-all check ' val-ve 399 -kvill seat to prevent fluid flow from third gear b,and release passage 422 to coupling feed passa.-e 411, but will pernut fluid flow from couplingfeed Dassag@ 411 tothird .-ear band release passage 422. 55 An additional one-way ball check valve 132 shovin in 'FIGURE 4 "Vill permit:Puid flow from @intermediate ran.-e pressure passage 402 to b@and apply passage 413 but will, prevent fluid flow from band -apply passage 413 to intermediate range pressure suppiy passage 402. An additional two@way check vajve 133 is provided. 60 Ball check valve 133 shovm in FIGURE 5 will block off detent press@are delivery passa.-e 428 in the event that manual valvc 70 is placed for interr@lediate range operation @and Dermit pressurefrom passage 402 to flow to passage 429. - In the evenl that passage 402 is connected to 65 exhaust, val-ve 133 will block off passage 40,2 and connect passage 428 to passage 429. Ope,ratioizal Slimmary The operation of the hydraulic control system in!con70 junction with the transmission to obtain the various drive conditions Nvil.1 be adparent from the following explat@ation: PARK AT-ID NEUTRAL 75 It is egnterrplatedthat manual valve 70 must be moved

13 to the Park or Neutral before the engine starting circuit is co..npleted and the engine may ill@,e started. V@ith valve 70 in Park, linka,-e connec"--d to Lie manual valve will cause a do,@, not shonvn, to en.-a,-e locking 'Leeth associated with load shaft 39 to positively prevent rotation thereof and thereby prevent movement of the. vehicle. With the engine started, pump 50 viill supply pr-,ssure to -inain pressu-re supply passa,@e 400. The pressure in passage 409 will be determined by the action of pressure regulator valve 55 and may vary between 66 and 94 pounds @as hereafter explained. With valve 70 in either the Park or Neutral position, drive ran.-e passa,-e 401, interinediate range passage 402 land low ran.-e passag-- 403 are all connected to exhaust throu.-h the ri,-ht-hand end of val-%re 70. Reverse pressure supply passage 404 is connected to exhaust by way of exhaust part 34. Pressure from supply passa.- e 400 is adnlitted to line drop feed passa,-e 405 by way oj' ports 73 and 79. Passa,@e 405 extends to port 1'09 of pressure boost vaINe 130. Sprin.@ 187 positions valve 180 toadmit line pressure from passage 405 toa line drop si,-nal passa,@e4G6tLiroughportsl89andl9Oofvalvel8O. Passage 4C6 extends to port 296 of pressure:drop valve 290. Passage 400 supplies line pressure to port 103 of throt'@le valve 90 @and th@s valve delivers variab,e pressure as heretofore explained to throttle valve pressure delivery passa,@e 407. Throttle valve pressure from passage 407 is adrnitted to the end of land 291 of pressure drop valve 290 throu,-n port 295 to coiitrol the -action of pressure drop valve 290. At closed throttle with relaxed acceleration p,-dal, no throttle valve pressure -,vill exist in passage 407, and spring 293 wiU position valve 290 to admit full line pressiire from line drop signal passage 406 to line drop feed passage 408. This pressure acting on land 57 of pressure retilator valve 55 will force valve 55 a,,ainst sprin61 to its niiniinum pressure position wherein th,valve 55 maintains a line pressure of 66 pouids. As &@e accelerator pedal is depressed, throttle valve pressure in passa.ac 407 increases, movin.@ valve 290 to the ri.-ht a.-ainst sprin.- 293. Valve 290 thereudon regulates the pressure delivered to passage 408 so tl@at the pressure in passage 403 diminishes ivith increase of throttle valve pre,ssure in passage 407. At full throttle, valve 290 wiR block off port 296 and connect passage 408 to exhaust port 293 to p@- rmit normal full ar-tion of spring 61. Pressure in passa,-e 400 will rise to 95 pounds. The action of pre,ssure drop valve 290 is progressive so that the pressure maintained in passag@ 400 by valve 55 may vary with throttle opening between a minimur@i of 66 and a maximum of 95 pounds. This action reduces pump noise and @at the same time permits the charge pressure to the hydraulic coupling to increase as the throttle is opened. In park and n-@utral, co--plin.- 11 is charged with ffi-,id. Line pressure is supplied by main Ene pressure passage 400 to porl 215 of coupling timin.@ valve 200. Spring 217 positions valve 200 to ad--nit line pressure from passa,@e 400 to couplid.@ signal passage 409 through ports 215 and 2' .4. This pressure acting on head 306 of valve 3- 05 positions coupling exhaust valve 305 to block off exha,,ist port 310. Coupling si.-nal passage 499 also e-kte-iids to port 224 of couplin.- feed limit val@Ve 22,9. Line pressure actin.@ on the end of @land 221 of va,lve 220 tends to move valve 220 to connect passage 400 to a branch 412 of a coupling feed passage 411. However, pressure in passage 4P@9 is not sufficient to caus-- this action and v@alve 220 - bloc'As off passa,@e 400 from passage 412. Passa-,e 403 exter@ds to port 150 of valve 'P 4l of the second to third gear shift valve assembly. Vlith valve 141 in its downshift -Dosition pressure is admitted from passage 4DO to a passa,@,e 410 throu_zh a restriction 156, the passage 410 leading to port 211 of coupling timing valve 2.90. Spring 217 posi@tions valve 200 to admit line pressure to passage 411 thro-agh ports 211 and 210, th-- passage 411 supplyin.- oil to fUl the coupli-iig. It will be noted that line prcssure supply passage 14 400 is continuousl y connected to couplin.- fee@ passak& 410 through restriction 156. However, upon an upshift from second to third gear drive ratio valve 141 Nvffl cgnnect passage 410 to passage 400 through parts 150 and .5 149 to bypass restriction 156. Thus, at light throttle openin.- in park and neutral, the initial supply of fluid to couplin.- 11 is restricted for smooth couplin.- action. At heavy throttle opening it is desirable to ffll couplin11 rapidly. At heavy throttle opening coupling 10 signal pressure in passa,@ e 409, actin.- on land 221 of valve 220, will move coup.ing feed limit valve 220 to admit line - pressure from passage 400 to coupling feed branch passa,-e 412 by way of ports 225 and 226 for rapid fiR Gf coupling 11. This action @occurs whenev er 15 the coupling is being fffled with working fluid. Valve 220 is effective at heavy throttle in park, neutral, first or third gear to by-pass restrictio n 156 for rapid. coupling fill. In a shift to third gear, valve 141 will by-pass restriction 156. 20 Coupling feed passage 411 extends to a ball check valve 399 and to port 369 of band release valve 365 for purposes hereafte r explaine d. In park and n,utral, band apply passa,-e 413 is connected to exhaust Itirough drive range presslre passage 25 401 and throu,@ h ports 80 and 85 of valve 70. Ball check valve 396 permits oil flowing from passage 413 to passage 401 to by-pass restrictio n 131 for rapid exhaust of fluid fron chamber 360 of b,and servo 40. Front clutch apply passage 427 is connect ed to a second to first gear 30 signal passage 415 through ports 241 and 240 of first to second govemor valve 231. @passag e 415 connects to port 285 of front clutch exhaust valve 280, to ports 277 and 276 of second to first downshif t valve 270, and to port 379 (>f low throttle exhaust valve 375. With cou35 plin.- 11 filled witli fluid, coupling feed pressure from passage 411 entering port 284 of front clutch exhaust valve 289 will position valve 280 to connect passage 415 to exhaust through ports 285 and 286. With coupling 11 filled Nvith fluid and with the front clutch piston 32 40 and @band servo 40 connect ed to exhaust, the transmis sion is condition ed for neutral operatio n. DP.IVE P.ANGE-LOW GE; A-P. Manual valve 70 may be moved from neutral to drive 45 range to male possible drive of the vehicle' Coupling 11 will remain charged with fluid in the manner horetofo re describe d. With valve 70 positione d for d@-ive range op.-ratio@i, line pressure from passage 400 is admitted to a drive passa.-e 401 through ports 78 and 80 of valve 50 70. Drive oil fro@n passage 401 enters port 188 of pressure boost valve 180 moving valve 180 to the right against spring 187. Valve 180 admits line pressure from passage 400 @o line drop si,@nal passa,@ e 406 through ports 191 and 190 and to line boost passage 416 through 55 @ports 191 and 192 ' Pressure en'Lerin g port 299 of pressure regulato r valve 5.5 actina on piston 300 will boost the strength of sprin.@ 61 to raise the line pressure to a maximu m of 164 pounds. As heretofo re explaine d, pr,- ssure drop valve 290, controlle d by throttle valve 60 pressure , delivers variable pressure to line drop passa,-e 408. At closed throt-tle the pressure mainta' med by valve 55 in first gear operatio n will be 115 pounds. As the throttle is opened, line pressure will rise to a maximu m of 164 pounds. 65 The line pres sure boo s@, pro vide d in first gea r driv e ove r - that pre vaili ng in neut ral op,- rati on is to pro vide ade quat e hold ing cap acit y of ban d serv o 40 to pre vent sli_p pag e of the ban d and to acc omp lish fast cou plin g feed . The high line pres sure acti ng on land 221 of 70 c o u pl in g fe e d li m it v al v e 2 2 0 w ill m o v e v al v e 2 2 0 to a d m it p r e ss u r e fr om p a ss a. -e 4 0 0 to c o u pl in g fe e d p a ss a g e 4 1 2 th r o u g h p o rt s 2 2 5 a n d 2 2 6. - Il u s a ct io n b y p a ss e s r e st ri ct io n 1 5 6 to in s u r e fa st u n r e st ri et e d c o u pl in g fe e d. W it h c o u pl in -. 1 1 fil le d w it h fl ui d, p r e ss u r e m u st 75 b e s u p pl ie d to c h a m b e r 3 6 0 of b a n d s e r v o 4 0 to e n g a g e

15 band 35 to estabh,'Sh first or low -ear drive. Drive range pressure supply passage 401 is connected to band ap-ply passage 413 through restric-tion 131 to smooth the enga,- ement of the band. Part throttle valve 95 -at light throttle openin.- will block off port 106 from port 107. At partially advanced throttle, valve 95 will cor-inect port 106 to 107 to by-pass restriction 131 to admit pressure from passage 401 to band apply passage 413 to more quickly enga,-e the band. This prevents undue band wear as rnight otherwise occur due -to slippage during band enga,-ement at advanced throttle positions. Ball check valve 396 v,,ill prevent flonv of fiuid from passage 401 to passage 413 through the ball cher-k valve. With coupling 11 filled with fluid and band 35 engag ed-, the transmission will be co@nditioned for first gear forward drive. It will be noted that drive oil from passage 401 is admit' ed to a first gear passa.-e 417 through ports 242 an-d 243 of first to s,-cond goverpor valve 23-',', when the valve - ft is ii its first -Car or dowr@sh; position. Pa@sa@-e JI-7 is conr@ec'Led to a passage 413 througa ports 151 ar@d 152 or-' second to third gear -Overnor valve 141 when valve 1,4.1 ;s in its dowr@shift positioi. Passage 418 extends to pbrt 216 of couplin.- timing valve 200 -@nd to po:-t 382 of low throt'Lle exhaust valve 375. Pressure e-Titering port 2i6 ol valve 200 will assist sn ing 217 lo irlai--itain tli c f r co-Lipling timing valve in its lef, @-hand position. Pressure from passa.-C 418 is also co-@iductcd to port 371 of Band relea--e valve 365. Band rel@-ase valv,- 3.55 will ini,ially block off port 371 from port 372 to preve-@it flow of f-luid f.-om passage 418 to passa-e 419 and will co-@i-@iect passae 419 to passage 429 co n@ r. ected to port 212 of couplinl .q co, -ntiming valve 2,OYO, at lig'iit throttle opening wherei pensator pressure acting on land 367 ol@ valve 365 is low. Passa,@e 420 will be con@ected to ex'@@aust through ports 212 and 213 of couplin .- timing va'ive 2v'O. The coiinection from passage 419 to Passage 420 is through porLS 372 and 373 of band re' iease valve 365. A@lso at light throttle openin,@, spring 385 will be effective to posit@On low throttle exhaust valv,- 375 to connect passa@-e 4'a'to passage 421 th.-ou,- h ports 382 and 381. Passage 421 admits oil to the left-hand side of free piston 391 through port 394 causing the p;ston to assume it- righthand position. At heavy thro',tle openin-@ compensator pressure acti-.i.- on land 367 of band release valve 365 pius couplina feed pressure acting upon land 366 of valve 3.55 will cause va'lvc 365 to move to its left-iiand positioq, compressin-. spring 374 and connecti-ng passage 4-148 to passage 419 through ports 371 and 372 and blocking off port 372 from pbrt 373. Pressure in passa.-e 419 will flow through ball check valve 398 to a passage 422. Ball check valve 397 will close to prevent oil @low from passage 422 to passage 421 ar@d ball check valve 399 will close to prevent oil flow fror@l passage 422 to passage 411. At heavy advanced throttle, throttle valve pressure acting on low throttle exhaust valve 375 will position valve 375 to connect passa@@e 419 to passa@-e 421 through ports 380 and 3811 of valve 375. Pressure from passage 422 is blocked off from a passag-- 423 by land 251 of first to second shift valve 232 when valve 232 is in its downshift position. it will be noted that in first gear drive, throttle valve pressure from passa,-e 407 will be admitted throu.-h ports 255 and 276 of shift valve 232 to a passage 424, through ball check valve 263 to a passage 425. Valve 263 will block off passage 493 from passages 424 and @';Z5. Pressure from passage 425 will position modulator valve 233 to admit modulated throttle valve pressure to the chamber containing springs 266 and 267 throu,-Ii port 261, passa-,e 264 and port 263. The throttle valve pressure acting on valve 233 will cause, the valve to compress spring 267 to tend to retain silift valve 232 in its downshift position. Modulated throttle valve pressure acting on land 252 of shift valve 232 and the force of sprin.- 266 ,@vill also tend to maintain the shift valve in its downshift position. At some vehicle speed dependin,@ on which 3,110,198 16 speed, gove.-ror pre.-sure from governor pressure delivery passa-e 228 acting upon land 234 of @overnor valve 231 will ciuse the goverr@or valve 231 and shift valve 232 to upshift to establish second ar drive. g, DRIVE rANGI,-SEI-O:-,-,D GEAP. With first lo second shift valve 232 and governor v-,Ive 231 moved to their unshift position to establish second ,ear drive, coticlin- 11 w-',Il be emptied and front clutch 10 pistoi 32 is pressurized to es'Lablish drive in second gear. Brake band 35 remains engaged. With valve 232 in its upshift position, passa--, 424 is connected to exhaust tbrough ports 256 atid 257 of valve 232, a passage 428, and ports 122 and l'@3 of detent valve 112. Drop in pressure in passage 424 pern-iits ball check valve 263 to 15 seat and connect passaa 425 to exhaust throaah passa-e @e 403 and ports 82 -,Lnd 85 of valve 70. Passage 417 is coinected to ext-iaust through ports 243 and 244, passag.- 247, and port 24,5. Passa@ 418 will b@- exhaiisted througq e e passage 417 to reliev th- ioressure aeing oi the end of 20 land 206 of coupling timin.@ valve 200. Li@-ie pressure f.-om drive p,,issa.-e 401 is admitted to fro-nt clutch apply passage 427 through ports 242 and 241 of val,,,e 231 to enga,,--, the fronl gear unit elti'ch. Front clutch apply pressur-- iii passage 4,27 is admitted throu-h port 194 to the 25 space bet-,veen land 21-)l of col-iplin- . timinl- valve 200 v atid land 134 of pressure boost val c lf,'O. Coupli g tir@ling valve 200 is forced to its right-hand position compressin.- spring 217 and con-tiectin.- coupling sia al passage .-n 409 to exiiaust throu@h ports Z!4 and 213 of valve 200. 30 Sprin.- 303 of coupl'ng dump valve 305 is thereupon efie.t;ve to posit;on valve @103 to connect flu;d coupling 11 to ed passage 411 is connect@-d to exhaust through ports exhaust thro,,i,-q port 310 of dump valve 305. Coi,.pling le 35 2'-@O and 209 of valve 200. Pr--ssur,- boost valve 180 will be moved *o its left-hand posiion by spring 187 and presI suracting o-ii the end o' land 184 and will connect line pressure boost passage 416 to exhaust through ports 192 a-..id 193 o.' valve 130, rev--rse pressure supply passage 404 40 Pr@d porls 83 and 84 of valve 70. Valve 180 will also con-@lect line drop feed passage 405 to Iiii-- drop signal passage dO6 through ports 189 and 190. Pressure drop valve 290 will thereupon be effective 'o vary th6@ line pressure in passage 400 between 95 aiid 66 pounds, depending 45 on t@rottle ope-ning. In second geir drive, band 35 remains engaged. Fluid pressiire from drive passage 401 is supplied to ba-@ld apply passage 413 throurestrict-' n 131. Band release pash io sage 414 is connected to exhaust throu-.h ports 208 and 50 209 of coupl;ng timing valve 200. DRIVE RANGE-TF-IPD GEAR With the vehicle accelerated iii second gear, G-1 governor pressure from passa.-e 223 entering port 148 of valve 141 acting on the end of land 144 of valve 141 plus G-2 00 -overnor pressure from passa- 229 enterin@ port 164 of e valve 142 and atcing ikoon land 160 of valve 142 wifl at some vehicle speed, depending upon throttle opening, cause the second to tnird gear sl-iift valve assembly to upshift to establish third gear or direct drive. In direct 60 drive, coupling 11 is fflled with fluid, front clutch 28 rei-nains engaged, and band 35 is released. AVith valve 141 in its upshift position, line pressure from passag.- 400 is admitted to passa-e 413 thro@,igh ports 153 and 152 of valve 141. This pressure applied to th@- end 65 of land 206 of coupling timin@ valve 200 permits spring 2'@07 to -.love the couplin,@ timing valve 200 to its left-hand pos-ition irrespective of the fact that front clutch apply pressure is actin.- on the end of land 201 of valve 200. Line pressure is therefore admitted from passage 400 to 70 coupling signal passage 409 through por's 215 and 214 of valve 200 to position dump valve 305 to prevent exhaust of fluid froni coupling 11. Valve 141 also admits line pressure from passag-- 400 to passa,,e 410 through ports 150 and 149, the valve 141 by-passing. restriction 75 1.56. Passa,-,,- 410 is cdntiected to coupling f6ed passage

3,110,198 17 411 throuoh ports 211 and 210 of coupling timing valve 200. Fluid pressure from passa-,e 411 will flow through check valve 399 to passage 422 leading to port 254 of first to second shift valve 232 ard be admited to passa,-e 423 through ports 254 and 253 of valve 232. Pressure from 5 passao.e 423 wiH be admilted to band release passage 414 through porls 207 and 208 of coupling timing valve 200. Band release pressure in chamber 361 ol@ servo 40 plus the force of spring 358 will be effective to move piston 359 to release band 35 irresp,-cllive o'l the effect of band apply 10 pressure in chamb.-r 360 of sorvo 40. Front clutch apply passage 427 is supplied with fluid through ports 245 and 241 of first to second - governor valve 231 to engage clutch 28. Viith coupling ILI filled with fluid, clutch 28 engaged 15 and band 35 released, the transniission is conditional for third gear or direct drive. TI@,II@;G OF 2-3 SHIFT A shif@t from second to third gear may occur at a very 20 light throttle opening, with the throttle further - advanced to a medium throttle range, or N@iith the throttl-- - fur-ther opened to an advanced or hea,.,y throttle position. Band release accumulator 390 is provided to vary the timing of release of band 35 for different conditions of 25 throttle opening. Considering a Eght throttle shift from second to third, when second to third gear governor valve 141 upshifts, line pressure fror-n passage 400 is admitted to -oassag.- 41,3 through ports 153 and 152 of valve 141. This p,ressure , 00 from passage 418 acting on the end of land 206 - counteracts -the etect of clutch apply pressure acting on land 206 of couplin- tin-iing valve 200 and permits spring 217 to move valve 200 to its left-hand position. Pressure from passage 418 is also admitted to port 332 of low - throttle exhaust valve 375 and to port 371 of band release valve 35 365. Durin- the interval in which coupling 11 is being filled with fluid, band release valve spring 374 will - position valve 365 in its right-hand position. Compensator pres- 40 sure in passage 425 ac@ing on land 367 and couplin.- feed pressure in passage 411 acting on land 366 of valve 365 ivir be relatively lo-@v so that spring 374 may expand to position valve 365 such that land 368@ will block- off port 37J and connect passage 4--g 9 to passage 420 througa ports 372 and 373. Low throttle exhaust valve 375 will be 4,5 placed in its left-hand position by @spring 385 such that passa.-e 418 wiR be connected to passage 421 through por'Ls 332 and 381. Line pressure admitted from passage 400 to passage 418 throu,@h ports 153 and 152 of valve 141 of -the second to third gear shift valve asembly will 50 pass tnrough passage 421 to port 394 of accumulator 390, causin.- piston 391 to move to its ri.-ht-hand position adjacent port 395 of accumulator 390. Line pressute admitted to passa,-e 410 by valve 141 is admitted to - coupling Leed passage 411 throu,-h ports 211 and 210 of valve 200. 55 Pressu-re from passa,-e 411 flows through valve 399 to passage ','-)2, throu.-h ports 254 and 253 of valve 232 to passa-e 423 and through ports '@07 and 203 of valve 200 t, b-and release passage 414. Pressure in passage 414 acts on the right end of piston 391, but since pressure also 60 is acting on the left-hand side of piston 391, the piston is unable to stroke and is of no effect. The pressure in passa.-e 414 will rise rapidly and cause piston 358 of servo 40 to move to release band 35. There wiR th,-refore be a rapid release of band 35 at a li-,ht throttle shift frotn 6,5 second to third. Considering a medium throttle shift from second @to thi.-d ,-ear, throttle valve pressure actin,- oil the end of land 376 of low throt' le exhaust valve 375 will move valve 375 to its ri,@ht-hand positionwhere land 376 blocks off 70 port 382 and passage 419 is cc)nnected to passage 421 through ports 381 and 380. During the interval in which coupling 11 is being filled with fluid, the effec-t of compensator pressure on land 367 and coupling feed pressure on land 366 will not be sufficient to ov--rcome spring 374 7,5 is w-ld spring 374 will position band release valve 365 in its right-hand position wherein passage 419 is connected to passage 420 through ports 372 and 373 of valve 365. Passage 429 is connected to exhaust through ports 212 and 2iL3 of coupling th-ning valve 200. Since passage 421 is connected to exhaust, band release pressure entering port 395 of accumulator 390 will cause piston 39,1 to stroke to the left toward port 394. This stroking of piston 391 delays pressure build up in band release passage 414 to delay release of band 35 untfl the coupling pressure is sufficient to render the coupling capable of carrying the load. Assumin.- a fixed throttle opening and conseque@nt fixed compensator pressure, rise of coupling feed pressure in passage 411 will cause band release valve 365 to move to the left to block off port 373 from port 372 to prevent any further exhaust of fluid through passage 4@20. Fluid remaining in passage 421 and on the left-hand s;de of piston 391 will be @trapped to prevent any further stroking ef piston 391. Pressure in band release passage 414 w@"ii then rapidly rise to release band 35. At he-,i,/y th-rottle shift from second to third gear the action is the same as at medium throttle shift except for the timing of mcvement of band release va.ve 365 to its lefthand position wher@-in land 363 blocks off port 372 trom port 373 to prevent further. exhaust of fluid from passage With a heavy throttle opening, compensator pressure in passage 425 will be relatively high and may approach line pressure. Value 365 wiR therefore shift to ILS left-hand position to block off exhaust passage 420 -,vith a lower COUDlin- feed pressure than is trlie at medium thlottle opening. Band 35 will therefore be released sooner with a heavy throttle than at a medium throttle openin,-. Line pressure maintained in 7)assage 400 by pressure r--,-ulator valve 55 is the same as that existing in drive range second gear operation and may vary between 95 and 66 pounds. PAP.T TH-LZO-LTLE 3-2 DOWNSHIFT It wiR be noted that throttle valve pressure from passa.,e 407 is supplied to ports 119 and 120 of detent valve 1,12. As the accelerator pedal, not shown, is depress@d to suppl.y fuel to the vehicle engine, valve 112 is moved to conpect passa,@e 407 to a part throttle pressure delivery passage 426 through ports 120 and 121 of valve 112. This action occurs before the accelerator pedal is fully depressed and at a time ,vhen throttle valve pressure is less than f-ull line pressure. With the second to third speed shift valve 142 in its upshift position, pressure from passage 426 will be admitted to passage 165 through ports 163 and 162 of valve 142 and to the end of modulator valve 143 through port 169. Valve 143 will move to the left applying force @to spring 174 tendin- to move the 2-3 shift valve to its downshift position. Al@so, modulated throttle valve pressure will be admitted to the chamber containin.- spring 174 through passage 173. This modulated pressurewhich is less than throttle valve pressure in passage 407 acts on land 160 tendinto downshifL shift valve 142. If the vehicl.- speed consequent G-1 and G-2 governor pressure are not too high a forced part throttle downshift @from third to second gear will result. DETP-NT 3-2 DOW-I\TSHIFT In tj'ae event that detent valve 114 is moved to its detent position by depressing the accelerator pedal for full throttle opening, valve 114 wM admit pressure from passa,-e 407 to a passage -428 through ports 120 and 122. This pressure supplied from passage 407 will be fuR line pressure and wiU be admitted through ball check valve 133 to a passa,@e 429 connected to port 1171 of modulator valve 143. Since land 167 of valve 143 is of greater diameter than land 166, valve 143 will move to @right @to admit line pressure from passage 428-429 to passage .173 through ports 171 and 170. This line press7are actin.- on the end of land 160 plus spring 174 will eause the shift

19 valve assembly to move to its downshift or second speed posi-tion irrespective of the effect of G-1 and G-2 governor pressure tendin-. to upshift the assembly. PAR-L THROTTLE 2-1 DOVVNSHIFT In the event that the vehicle iS OpeTating in secord gear, a forced donvnshift from second to first may occur, provided the vehicle speed is not excessive. The action of throttle valve pressure tend.;ng to downshift the first to second shift valve assembly was discussed in connection with the first to second shift valve and need not be repeated here ot@her than to state when G-1 governor pressure is not excessive, the combined effect of spring 266, spring 267, throttle valve pressure arting on land 258 of modulator valve 233 and modulated throttle valve pressure acting on la-.id 252 will overcome -the eftect of G-1 pressure acting on l@and 234 to cause the 1-2 shift valve assembly to assume ilts down-shift or first gear position. In accomplishing a downshift from second to first -ear it will be noted that f@ront clutch apply pressure from passa.-e 427 will be admitted to passage 415 through ports 241 and 240 of first to second goveriior valve 231 v,,hen the valve 231 assumes its downshift position. P-ressure from passage 4@15 entering port 276 of 2-1 downshift valve 270 imill move valve 70 to t@he right against spring 273 to connect passage 415 to exhaust through ports 277 and 278. Valve 270 regulates at a predetermined pressure, for example 30i pounds and vihe-n p-ressure in passage 415 is @reduced to 30 pounds, sprin.- 273 will be effective to position valve 270 to block off exhaust port 278 from port 277. This 30 pound pressure will retain the,front clutch in slippin- engagement durin.- the inter-val in Nvhi@h coupl-ing 1.1 is . being filled with -iquid. When couplin.- 11 is filled with fluid, coupling feed pressure i,n passage 411 rises and causes front clutch exhaust valve 280 to move to @the left against spring 2S3 to connect port 285 to exhaust rdrt 2E@6. T-nis completes the exhaus-t of the front clutch. - The two stage exhaust of the front clutch on a second I to first downshift prevents engine runaway during a forced downshift and provides a smooth tra@nsit@@on of drive ratio. Front clutch pressure is also exhausted through restrictio@n 269. In the event of a close-d thro-ttle downshift from second to first gear, ,vhen throttle valve pressure in passage 407 is less than a predeter@in-ined amount, for example 25 pounds, spring 385, will be effective to pos;tion low throttle exhaust valve 375 in its lefthand position such that passage 415 is reonnected to exhaust through ports 379 and 379 of valve 3-/S. This will provide a fast exhaust of clutch 2,3 at norinal closed throttle downshift from secopd to first. However, during a forced downshift at heavy tbrottle, throttle valve, pressure will position valve 375,to block off port 373 so that the tv,,ostage exh@aust controlled by valves 270 and 280 is obained. liNTilCIZ,IIEDiAT-B r,,iiNGrl, Drive range selector valve 70 may be positioned to select intermediate range operation. When so positioned, valve 70 admits line pressure from passage 400 to intermediateTangepassage4OZthr,oughports78and8l. Line drop feed passage 405 is connected to exbaust through ports 79 and 84. Line pressure from passage 40,2 Rovis through ball check valve 132 to band apply passage 413 to engage brake 35. Pressure in passa,-e 41,3 will also unseat ball check valve 396 to permit line pre-ssure from passage 401 to enter passa.-c 413 thtou.-h the check valve and to bypass restriction 131. Pressure from passage 402 @,vill ffow through ball check valve 133 to passage 429 and will be delivered to the spring chamber containing spring @174 to retain the second to third shift valve assembly in its downshift or second -ear position. The action is the same as that described in connection with the detent forced third to second gearr donvnshift. BaR cheekva'ive 133 will block off passage 428 from passages 402 and 429 and connect passage 420 to passage 429. 3)110;198 20 In intermediate range operation, first to second shift valve assembly functibn in the same man-.ier as that described inconnection with drive ran,-,- operation. Intermediate range opetation is provided to enable the operator to accomplish a closed throttle downshift from thrd to second gear at high vehicle speed. This is particularly usefill for obtaining engine bral-ing in descendi@ng long or steep hills, and may also be -Lsed to delay upshift from second to -third g-,ar for Tapid vehicle ac10 celeration as desired ' When operat,,.ng interm@-diate, ran@,@e, first gear, the line pressure ipaint ained in passage 400 may vary bet,,veen 115 and 164 p<)unds in the samemanner as when operating in drive -range first gear. Line drop fe--d passage 405 15 is connected to exhaust, but lino, pressure passage 400 admits lin-- pressur-- to line drop signal passage 406 throu,@h porls 191 and il9G of pressure boost valve 180 and admits pressure to Ene boost passa.-e 416 through ports 191 and 192 of valve 190. In first gear opera-tion 20 valve 290 functions in i-ts normal -manner heretofore described. Upon an upshift from first to second gear in intermediate Ta-nge the line pressure will be maintained at a constant 95 pounds and will not vaty between 66 and 25 95 pou-@ids as is true v,,hen operating in drive range second gear. F-ront clutch pressure entering port 419 of p-ressure boost valve 180 moves valve 180 to its righthand position, connecti-@ig line drop feed passage 4,9,5 to line drop sig-rial passage 46,6 through pgrts 199 and 190. 30 Land 133 pre@,rents flow of fluid @fto-m passage 400 to line boost passage 416 through ports 191 and 192. Since passage 4C@6 is connected to exhlust throuah passage 405 and si-nee no pressure is admitted to passage 416, spring 61 will maintain a constant 95 pounds line pressure@ 35 Passa.@e 416 is connected to exhaust through ports 192 and 193 and reverse passage 404. Line pressur-. in intermediate range third gear operation is the same as -that in second gear interr@iediate range, or 95 pounds. Valve 180 remains in the same position in third gear as in second 40 gear and the action is, the same as in second geat intermediate range operation. LOW P.A,@GE OPIIRATION In low range operation the low @range passage 403 is 45 supplied wi@th line pressure through ports 78 and 82 of va e 70. This pressure will pass through ball valve 268 to passa,@e 425 and enter inodulator valve 233 through port 260. The action will be the same in low range as with a forced downshift from second to fir.@t in drive 50 ran,@e except that full I.;.ne pressure rather than throttle valve pressure is acting to maintain the shift valve assembly in its first gear position. At moderate vehicle speeds the transmission wfll be maintained 'm first gear with a closed throttle. Line pressure control in low 55 range first gear, second @gear and third gear is the sa@me as that in intermediate range first gear, second gear and third gear, respectively. REVFIRSN @Vith manual valve 70 positioned in reverse, line pres60 slre from passa.@e 400@ is admitted to line drop fe--d passage JOS and tb reverse passa,@e 1,04. Dri@,,e range passage 4-,Ol, interi-nediate range passa.@e 402,and low range passa,@e 403 are all connecled to exhaust throu,@h port 85 of valve 70. Reverse passage 404 adn-iits lin-, pres65 sure to reierse brake p:@ston 34 to apply brake 33, to port 2.-,,@2 of first to second modulator valve 233, and to port 193 of pressure boost valve 185. Pressure enterin.- port 26"1 of modulator valve 233 is conducted throuoh passage 264 to the end of land 252 of shift valve 232 70 to hold valie 232 and valve 231 in t@heir downshift or first -ear positio-n. Pressure from reverse passa,-e 404 is admitted throug'@i ports 193 and 192 of pressure boost valve l'OO to line boost passa,,@e, 416 to cause pressure r@-@,1,.Iator valve 55 to raise t!ip- line pressure to a iraxi75 mum rf 115 pounds. Line pressure from line drop feed