claim: )05 1. A poiver coiitroller for use iii -,t - p@-iei-tmatic despatch system haviiig a traiisiiilssion tube, iiieans for creatin- a carrier pi-opellin, air current iii the tub.e"and a valve foicoilntrolliiig carrier propellin(r air flow tliroligli 110 the tu@e, s,,ticl coiitroller ezomprisin,r a iiiotoifor operatin- the valve aiid electro-mal@netic means for colitrolliilg tlle motor, fixecl control meaiis and ,t cont,,tct movable iiito e,.igagement with the fixecl coi-itact to 115 coinplete ai-i electric,,il circuit throiigl-i the electro-magnetic iiieans, ai-id meaiis for moA,iiig the movible coiitact comprisi-n.- a pies@.!ui@e respoiisive elemelit and a coi-le-,l coiiirilig, the sprin(- beiiio, substiii- 120 pi,ession Sp tially collapsed by full moi,.emei-it of the pr@ssure respoiisive element an(,l ther-eby maiiitaini-i- the movable contact in engagemeiit witli t-lie fixed contact mealis i-eaardle,s I 5 of sli glit subsequent Diovemei-its of tl@e pressure i-espoiisive el-,meiit. 2. A p,ower conti-oller for use ii-i a puetimatic despatch systein of the vacuui-ii tvpe having a traiismissioi-i tube, aii exhau@ter connected therewith and a valve for coiitrol- l'O

1,609,123 ling carrier propellitig air flow throij,-h the ti-ibe, sa;d coiitrollei,- coinprisir)o, a iiao'tor for olwt,,iting the i7tilve, ai-i ele@troiiiagliletic de,,vice f6r deteriniiii-iio, operati,oii of the iiiotor a paii@ of pi-ieiimatics of i@elEit,ii,ely different a@ea, eieli pnetimatic li,,iiT"I I'lg a steli-i aiid noi-ii3all@ beii-ify exposed to tri@i-isn-iissioii tube pressuie, a resilieiit circuit closer mov,tble by each stem, and coiiti t i-tie,,iiis -ii2,aff ec 10 able @by the r-espec@ive 6itouit closei-s to close the cl@eiiit tlirouo-b the electro-n-i@,o;lietic device. 3. A poNver controller foi- use iii a pneumati.c despatch systoiii of the v,,tciLil-im t)Tpe 15 hav;n- a ti@aiisiiiission tube, -,iii exhatister a -itrolconnectecl therenvitli aiad v,,tlve for coi ii4(,@ cai,riei- pi@opellili(y aii@ flow throtioli -the ttibe, said coi@t'rbller comprisiiacr a inotor for ol)eratii-ig tle N,aIN,e, an electr@o-n,ia_andtic @le20 iiice @or deteriniiiillo,,opei@atioii o'f the iiiotor, ,i pair,6f pneumiiti@s 6acli iiormally e-@Kposel-I to traisiiiissioi-i tube pressi-ire, one 6T said ]',)ll,etlll)aties beiiig of (yre,,tter effecti,Te area ila, ,ii-i the 6ther, 'each 'pneiimatic haviio, a 25 steiii, ,ti@ aiiiitilar cont,,tet 1)late encire-Iiii(Y eac,li stem, i 9,prin![@ connectecl to e,,tch stem aiid resiliently stipporting the respect;ve coiitact plates, aiid coiitact meaiis ei-ioao-eable by the reqppetive,plates foi- closii-iu the eircui.t tl-ii-ou@h the electro-iii-,iglieti device. 3 c 4,. A po-wer coiitroller for iise in a piieii1-natic de-qpatch s@stem liavirig a transmissioii tiibe, m-oalis for creatiii(y cair@er prope.lliiiair flo-w th-ereiii, and a v,-tlve for cojitrolliii35 carrier.pl'OpelliDg air floiv tliroug',-i the tiibe, s,tid coi-itroller con-iprising a iiiotor f or operating said i,alve, electro-mao-netic meaiis controlling the iiiotor valve a pair Of auxtori-nally exposed to iliary pne'um, aties r -IDres40 sl_lre fllictuatioiis C()i,respondiii- to those 1 the transmission tub.e, one of s,,iid auxi.liary pneun-iatics respondi@g to sligl,it chai@(ye li'l prossiire in tl-ie transm@issioii ttibe diie t c) i i-i troduction of a carrier tl-iereby to close tho 45 eireiiit thro-Lig-h the electi,o-ma@yiietic meai-is, tn the other of said auxilia:ry r pneum,,itics esponding to the relatii,elv gr6ater cliaiige ill pressure in the trinsmission tube du6 to Opeliiiii(y of the iaiaiii valve, -,aid latter aux'@neumati.c there y cut in 0 50 ili,,iry b ' t g off c mnatinication bet@veen tlie transmissioii tul)i,and the first auxiliarv pneumatic.. 5. IV power.cohtrolle@ for use in a p,-ietimatic despatch s),stem 6f the vacu.ufii type -55 halitino, a t-rai ism'ission,tube in exholuster connected therewith and a -N,,ilve for coiitroliii@g car,rier propelling air floii, throu h the 9 tube saicl controller comp,rising a, motor coilnected to the M,,Liii@ i,alve f6i@ op'eratiii(y tiie 60 la-tter, ,tiid meaiis for determiliiiig o@er@t,i6ii of tlle motor coi4prising an el-ectro-i-nagnetic devie,e, a I:kneumatic respoiisive to the sligl-it ch,,ing in pressure in the transmission ttibe e incident to introd-Liction of a car,@,ier to close 05 tll(., reiiit, tb.roii(yli the i,,Iectro-in,,igiieti c clevice, a, second pncl-imatic responsive -tc) the greater chqiige iii ptessi-ire iii'the'tr@ii-isiiiissioji ttibe du@2 to opeiiing of tho valie Lherebv to cut off comi-iiunicatioi-i be't@veeii the first pii@iiiii@It@c aiid the 'ttibe, said secoi-id pneti- 71, matic also,'b@, its i,esponse to stich p,@,essure 6baii(re, actli,,ttiiig c@rcuit closiii,[, iiieaiis @Lo 1'Yl,,tiiitain the ciretilt tliroti-l-i the electi-o@micr11 1. w e r et'c device h n the fi st piieumatic be come's inop-eratii,e. 7 11) 6. A 'po-wer coiitroller for use in @,i j)i-i,eui-iiatic despatel-i s3,stem haitiii(y a t@-,Liisiiii-ssion ttibe, meiiis 'T-or creat-iii6@ c,,trrier impolliii(y air-flow tliei-eiii, aiict a for coiiti-6!liiig cai-.i@er pro])elliiig iir floNv'throii@l-h the tube sf) sa@:d coiitrolle c m 't -lotor for opr o prisiii,o , ii e,.-PAtino- the Illd an e@lect ro-i-iia(yiietic cleitice for det@ei-i-niniiig operatioi-i of 'th-e MO-' tbi,, a pa-iii of ai@tti,,ible eircil'it closers for closiii(,' the 'circuit tl-.rou@),h ille 8,5 eleet,@-o-inagileti.c dev@'cel a:ll@l ,i piieumintic for op.ei-,,itlll(,, each eircllii, lelose@, @,,aid piieu-@ inaties normallv beiiig 0:@cp-os@d 'to 't'ransn-iissi,oii ttibe pressure. olie of aid l@iieiin-ia@i s I es be;ng to presslire 611an g-, tl-iar. 90 the ,ecol'id, the lattei@ -",heii re!3pblid@iio, 'to pressure cl-iaiig,e clitting off 'i,he fii@t. plnetij@i-iatic fpom the ti@,,in.-,missloh tube. 7. A power controller !or use in 9, pneumat 915 ic dospatch systelia having t traiismlqsion f-Libe. means fcr creafing cari.ier impolling a@ir AOW in sa'id tube gnd a valv6 for controlIiiig carriei, pi@ol-elling air flow ih-rc)ui@h the tube, said contiloller comlitisiiig a mbtor for -rating th6 valve, and an eleot@o-m@gnetic 100 0 p levice for determining operaticn of the' tor, a pair of 'indepena@nily aetu@able @eirel-lit closers @or closliio- the ircuit 'thro-(i-@h c Cy the electro@magnetic (fevico, a pair oT, , I iiiaers@ 6t diiterent diamet-rs, a pigton iii 10,5 each cylin@er, the cyliiider of slmaller Iiiani eter constantly commitnicatiiig . w , ith the trans;'mi8sion ttibe, tbo, lai@.,er c@iinde@ @nor mally commu.i@ic,,itii-i,g witli iho sii@'aller c@liicle@ by means of a port in it i-de v@all a d 110 s s n mo@a ns for transiuitting move @ment fro tli4 m e pistons t6 the respecti-ve eire'u@it @lo the sers, larger piston respoiiding to sli@,,Iit prossiiile ch@iige to - actuate on.e @eircuit ef8set to @elose e el@ectromagii i, e the eiretilt thro-Ligli-th @i@'c 'CT 'e and the,smallor pi8ton iespondiiig to @L v ic relatively gre,@Lter pressure e-hange to close the- i3ort leiding t6 the la@g@r c@-iiiider and t6 h6tuate thie otli6r 6ire " ult el6ser to @keep th 120 e i@irctiit closed throtilh the electro-magn c device. 8. Pnei-imatic d6spatel-i ap I -Ltus ha par, ving a tran xh us c nn smiss ion tube, Aii e ,t ter o epted ihprewiih aiid a ma' ' ,ilve fo 6onirb'fliiig tn v r cetrrier pi-OP61iillg flow of ai@ t-hr6ii4h i@e 125 tube, a motor for oporatin- the main valve, a n electro-maunetic devico o'r detefmii-iifig oporation of the motor, h pair of I cylinaei@ closed at oiie eiid Ind op@en to'the ati-tiosp . h6i@e 13(l ot tlio- oiber, n. pisfon- n6.P.Mqlly - po'sitiotied

Tie-@ir the open oild of each c@,lincl,er, one eilinclei@ constilitlv coiiiiiiiinicatiiiop - witl-i -@ie tran--i-iiissioii tul)e ,incl hai,ing a port iii its ivall lef@d;,ny to the otier c3,linder; eacl-i piston being ol)erative to close a circuit tlirouo-h tl-io ele@ii-o-i-n@igietic d-.vice,, 4ulie pistoi-i "in the eilii-ider whieb constantly c6mrfiLinicates with tl-ie tr,,iiistiaissioi-i tube belig slower to respond to pressure chatige th,@i.n the otlier ani ivhen it does so resj)ond closino- the p-,i-t leadino. to tl-ie otber c)71inder. 9. A po-wer coiitroller f or use in a piietin,iatic despatch h@-ivin.- ,t transmission line aii.,,l a valvpfor coi-.itrollii-i, c-ari-ier propellin.g. P,ir flow in the line, s,,iid controller coi-nprising a pneumatic co,-inectecl to the vilve for operatitig the latter, pressure responsive me,ins for c(,ntrcllinp,, movement of tl-ie pneumatic to open ,tnd close the ancl. autoi-natic regulatino, meaiis for determining the r.inge. of presstire to 'wi-i,-]) ti-ie presq-ure responsive means is subjected. 10. A power coiitroller f or tise in a piaeumatic despateli s-vstei-ii of the vacui-im tv e liavino- ,t transmi@sion line an,,l an exhau'ster coj,iTie@2ted tlierewitli ,ti-id a valve for controlling c,,irrier propc@llin,)@ air flow tl-irough the Iii-ie. said Conti-oller comprisi-@ir meaiis responsive to relq.tii,el.), sligl-it d;fferences iii pressure in the line to cletermine openin(, or closing of the c,ontrollin- i,alve, respective13,, said mealis beiiio, equaily ope-ative Nvitl-iout iiiantial ,icljusti-iient wliether a hioli or lo-w vacuum normally be maint,,ii-@ied.ipn the line. 11. A power controller for -Lise in a pneumatic despatcli sl-steiii of the vaeu-Lim type baving a transmission IL--Libe, @n exh,,,.uster connected there-with, and ,t vnlve for control,ling carrier propelliiag .tir flow tl-iroligl-i the tube, said controller coinprisiiiy means for actuatin,q the i-alve, pressure sensitive means for determin,n- tlle o eration of the v,,Lli-e p ,ictti, g ineans, said pressiire sensitia-e , ttin means being oper,,itive at .i. predeterminecl pressure r,,in2@e sliglitli- I)elow atmosphei,ic pressure, anci-means f'or transiiiittin,@ pressure from the tratismission tube to said pref,sure sensitive means ancl ineai-ig for clian(,- 50 ing saicl tr,,tlismission tube pressure, if ol@ , ,t hi,@.ber or,der of vaeu-Liin, to bring it within saicl predeterillinecl pressure. rang@.- 12. A pom,er eontr6llor f or use in a pneurnatic despatel-i si7stem of the vaciium type ,5 5 hai,ing a trai-ismi'ssioii tube iii -wliieh a relatively higli range of vacuum ipressure norn-ialli, obtii_ns, an exhauster coni'lected to the tube, and a valve for col'itrolling c,,trrier propelling air:fl6-w througl-i the tiine, sai-d 6 controller coixiprising means for actuat " iT'- the valv,e. pressiire sensitive means for determiiiing operation of tl-ie valve act-Liatin(r means, said pressure sensitive means bein,; operative at a lower range of vac,-Lium pres65 sures than obtains in the transii'lission tube, and iilieans for tran,@i-.nittina tr,,insmission tiibe pressure to s,,iid presstire seiisitive iiieaiis ancl fo-r cliingin(-, siieli tr,-nsinittecl pressui@es to brin- thei-ia -witl)in the r,-,r,-e of operation of sai&pressure sensitile meaos. 70 13. A pov%,er controller for use in a p--,i@,Lii-ii,,itc desp@@.tcli systeiii liavin(r -L transiiiission tube, me,,iiis for ei-ettiii(- c,,irrier iml)cllijiu tii- flow in the tlibe, and a 1,,Ilve for coi-itrollino- carrier pi,opel.ling air flonv tlroti(-h the. 7 t-LiLe, said controller con-i,,-)i-I'sin" a presstir(, acti-iated ele-@iient sensitive',y rlespcns@ve Lo press-Lii-e fluctuitions ivitliin a normal r,,tn(ye varying lit@le from atmosl)l-ieric pr,@ssui@(,, iiieans for ti-ansn-iittiii(y trai-isiiiission ti-ibe 811 pressure to said pressiire actuitect elemelit, .9,nOL means fo@,- cliarigin- such tr,,insmitteO, pressure, if difrel-ent from th-, n,)rn-ia'i. radgcfor -%vl-iieh tl-ie pressure actuated eleiiient is designed, to ',,)ririg it ivitliin such range. 1-4. A po\ver coiitroller -for uEe iii t pn(@iiiiatic clespatel) svsteii-i of tl-ie Yaciiiii-i-i type lia-v,ip.(r 11 tiLil)e,, ,in exi),iiistei, coi-iiiected t],@ei@eivith ai-id a for cont-,-olliiiq cirt-ier pr(-pelliii(- ,tir flo@v, tlii-o-c,-Ii the tiibe,.saicl controllei- compi-,,-,ing a c,,Lsiii,r liavino, a 1-@lici-ein, stid el-iimbel-c ommiiiiieatiii- )vitli the traiismi@sion tLiL-c. d.- presstire ,tctiiated eleia-l(,,nt i'ormi@'1,(_ oii(', -ieiit Avall of said sail, eleii seiisitivelv i@espo,.i:-ive, to ,i loiA,(-r of i,ac,,iuii-i pi-esQ-Lii@es tl.,aii tliit o'i@ the i-viission tiil)e, ancl iiieans for :)(Iii-iittiii(y atiiiospliei-ic air t,) s,,a;(l cliiinl)er ivliere'@iAT to I-ectuce the vaciiiii-ii tlierein aiid bring i ivitliih the raiige of pi-ess,,-,.res to ivlilc'ii .@.-Lid eleiiient is respoii-%@ii,e. 1,5. A poiver controller for tise in a pi-@eiiiiatic despate'l-I s,-sten-i lia-v@liig a 'Lr,,iiisiiii@sioii tiibe, i-neans for ei-eatiii(y e-rrier j@Illpellinn- 105 qlr 41ow in the tul,@e. a@cl a v,,ilve for c,)i@'- trollii-t- c,,trrier fioay tllroilcr I the tiif,7e,, Saicl contr'oller coiiil)rj,;iii@-Y a pneiiniatic coi-ii-ic-etecl to the Y,-ili,e 'foil 6ppl@-,,tiiiotlic,, !,,it@ter, t casino- h,,ii7ii-ig a tliere- 110 iii coi-iimtiliic-,Itii-ig %-vitli tli(, tvibe@, ,,. presslire aetuatecl (-,Ielllent 'torillin',T one iv,,d] of F,,.iid chaii-iber, ii-leplis aetti@ll,)Ie s,@iid eleineiit@ for cleteriiiiiing operat'ioii o! the piietiitilitic, sai(I eleiiieiit be;i-ily ilespoll- I 'I,) sive to a r,,tnge of press,,ii-es ne,,irer to i-@tmosPIlei-le pressiire tbaii ol,tains iii the iiiissioil tiibp,, and I i)resstii-e actlitte(l cleviee for opeiii-ug qpid chai-iaber to the ,)tiiioqpliere wlierebv alitomatically to i-naintaiii the pre:- 1'211 stire tli@-rein -witbin the i-piaee @it i7llich saicl presstire seiisitive eleiiiei-it is opei-ative. 16. A power control.le'r T-or -LiFe in ,i I)n(,iiinat,,C clespateli -,)7ste-.),i of the vaciii-..iii t,)71-@,e, F@ (, 1, 12@, h,,,iving ,.t trtiis@-@issioii tiil,)e, qTi coi-inectect tlierewitli, ,iiici -), -vali,-e for coiiti,olline@ carrier propelli.ng ,iir floly tliroll,)@li tlie, til@ei sctid cotitroller coil-iprisiiig ',I plioi-ill'iatic coniiectecl to the vali,e for ol--)(@,ratiliQ@ tlie, latter, an aiixiliary valve for - cleterininiri 9

1,609,123 7' @ietti,itioi.i of tl-ie pneiiii-iatic a cas,,nf,. 1-iaNino-i, cliai-iiber 1). @i-vitli tlic, thereiii coiniiitilii6atin,; ti-ansmission tul)e, @tn eleiiient respolisive to pi-esstire fltictliation iii said cli-,ii@iber to ,5 operate @ tlle Ltixiliai-.)7 valve@. aiid iii-,an3 @espoilsilte to ATactitiin in e.7@cess of ,t predeterii:iined an-iotint ii-i the traiisinissioll- tiibe to admit ati-i-iospheric air to s,@i-id chamber. 1,7. A poaver coiitroller for use ii-. a pneuiiiatic Otesp,@tch systeiii of the vaciiiii.11 ;type having @ tr,,iiisi,.iii-sion t-Libe, aii exh,,,.uster coi,iiiected tliereivitli, and a valve for conti-ollii-ig carrier prol)ell.ino@, air -flo@i, 'LIirougli the ttil)e, sai(I 6oiitroiier c6mpl,i9irig a piietiii-iatic c6nnected to the vaIA7e T-or oi:)eratiiig the litter, said pneiiiiiitic beiiig ex@)oged o@ oj,ie sicl(, to exliiiister pressi-,.re and iiorii-t,,iljv clos(,,d 1'rom tlie atiiiosl)liero at its olu]icr Sid(,, iioriii,,tlly clog6cl til,,iliary valv-- i-.oi, ,L(Irpittin,ttiiiosl)lievic pi@,essiire to tict iipon 'LI e l@,,tter @zide o:f tl-ie pi-ieui,,i,,ttlc, ineai-,,@ f,)i, orer@iting,-. the valie coiiapi,isii-ig all y auxiliary pnoui"n,,ttic formin@g, a. moval)le I,OTI @ Icliaiiiber coll'liiiiinicating ivitli tlie, tr,,itipiiiislion ttibe,, aiid a pi-essuro aetti-ite -1 -%Taii,e, oper@iblo to ,Lcliiiit atiyiogpliei,ic prcssilrf-k to sqicl clianiber' in clirect ratio to tl,e illin itacutim in the traiismiss,"cn, tj-- @be aboa,o, a predetermined poii-.tt. 'LS. k I)ower controller for use i.11 a pneii-, ii)@,,tic despitch sy@,tem liavino- a traiisiii,ssion tube, me s@ foi@ c@re, tting ci@i.,@,,ier iii-ipelling Ilir f@low in saicl ttibe, and a, valve J'or COI'Itrolliiig e,,trrier propelling air floii, tliroligh the ttibe, said controller comprisiiig a pt-ieumatic connected to the valve for operatiii,(,y tlae latter, sai-d piieun-i,,itic beino: exposed 6n oiae sicle to transmission tlibe @resstire ancl, noi@mallv closecl froin the ati-iio@pl-iere @it its 4( other side, a iiorilially closed au,\illlltl-y i-alve for ,I.clmittiil, atiiiospheric press-Lire to -,tet tipon latter side of the pneum@ti.c, @for opei,,,itin,,y the auxiliary v,,ilve coiiiprisin@z in auxiliary piieumatic Torn-iing @t mo-,- ible ivall for a chamber comiiiiinicatipg Nvi tli the traiismission tube, a iiorinally closed ITI,tlVe for ,tclmittin atmospheric air to stid 9 ch,-i ]Der, ,i,iid a pnelimatic ex osed to tritns. I"? p 1','IISS@LOii tiibe pre.-sure foi, opening saicl A,@ilve. I'@). A poiver controllei, for Lise in a piieiiiiia.ti.c despatel-i s@,stem of the Aacut-@m tl,l)e li,)@%,iiig a ti,ai-isi-iiissi6-n tube, aii exlictu,,t@r connected therewitl-i "lild i, valve for controlliiig carrier propelling air flow tliroti,gl-i ti-le t-Libe, said coiitroller comprising @i piaeum,,,.tic connected to the vtlve for operatii-ig %the latter, saicl I)neumatic being exposed on oiie Fide, to exliauster 1:)ressure aDd 1101'Mally CIO-e,(-,l floiii the ati-ii@OS@here at its otl-i(,r sicle, iioi-ii-i.@illy closed atixili,,try valve for tclii-iittinofitn-iospl-iei-ic pressure to act ul)o-,i the lalu-tei- @-,Ide of- the pneumatic, illei,ils for oper,qtipg the atixiliary val-,,e coinprisili-@Y 111 aiixiliary pneumatic formincr a movable'w,-Lll f r a 'cliamber co iu @ea 0 m uni ting witl-i@ the ti-ans,,@.vlission tiibc,,, recipi,ocable sleeve iai,i,-i I @,i -,t port 4'oi, air to said sti,@ld i,,al@@@c, beiii(r closecl, ai-icl, - t. netipi@ atic l'or opoi,in(y said 1 ,,dlve. 20@ A poNA,er coiatrol'Ler for ,ise ii, I a I)netii.,iatie desp-atell svst-,;Cia-i of the t@ypc, ti@11.111slylissioi-i @ tube, an exliau-qter c!oniiected@ tliel-ewit@h iiid a val e for coiiy t rolliiao, c@iri-iel- p,.opelliji:,o;: iii. floiv thi-@ the tube, said controller coi-iiprising a iiiain I)lioi:iii-ia,tic co-nriectcld to the i,-,tlve foi- o,,@eratiii(y the If-ttter 1-iieans for cleteriniiiiiaool)erqti(in of the ,)iietiiiiitic comprisincy ail auxi@l' -ry @,ie,, "Ltic T-orii ig .i iiiov-able la -"n 10-1. -I el m er, coi-RlyitinicatinL(.y ii,;,tli thB ti-,insiiiissi.oii tube, ,ind iyieans for adinittil'IO'- atn-iosl:)heric -,ir to said cli,,tiiiber coiaiprisilig a c)@iiiidi-ical (,I-Iicle,.a sleen.-e valve slidin a v i'n @o: I a i)ort g tlie griiide, said valve h of inverteo V-shape in its ivall-sai'cf poi,t iloi-beii-ig disposed ivitl-iiii ,tnd beloiv the ciid of the guid@, aiid'iiiean8 for inovitig til e sleex,-e to expose the port' beyoncl tl-ie end of I thegu;-cle. 21. A po-"-ei@ coiitroller for use in a pneu-, ",,i,,itic (lesp,-,teli s),-st6iil, of the vaeliuiii type h-,,i@,@iiio, q. traiisitiission tube, an exh'iiustei(,oineeted there-"7ith ,ii-id d valvo foil COl'y7 t-@-olling carric!r propelliny. -w flarougli - @), ir fl6 t-lie tlibe. s,,tid er coilt tt roller compri,qlno-l a mtin ],)ii'euiiiatic cornectecl to th e v-,tlie 'f.6r Opercitii-ig the 1,-.tter, a casin(, havin, o, c-oiiiiiiuiilc,,itin(,, cliaiiab rs, one ,it least of said c chambers coinil@unicatin(- witl-i the -traiismissi6n tube, means responsive to pressui@e flucttiatioii in one of said chambers for deterniiiiing 61)eration of the main pnetimatic, ,Lii a-Lixiliary pneuinatic ii-i ar).other cliambet, s,,,,icl ai-i2zi.liary p,- ielimatic having a stem, ,incl i valve actuable by said: stem for admitting aii@ to said l@itter cli,,tl-iiber. 29,. A poai,er controller for u I se in a pneum,,itic despatch s3TSteln 111,Llling -,L tr ansmisSIOD tube, iiieans for creating carrier impelliner 1-1 air flow tli6reii-i, aiid ,t vali7e for controlling carrier propelling iir flow througl-i the tiibe said coii'urollei, coii-il)rising a iqaiii pnotiiii,,.itic coiinectecl to the i,alve for o,,)eratii-l(y I lattei,, i, casii-ig havin,7 coiiiiiiunica . tin t'le ellimbers one i,t least of said cliai-.qbers colil- 9 13-itinicatino@ -Ni7ith the tr,,tiismi-qs-l-oii ttibe me,,tns respor.@@ive to pressure fluct-Liation i-Ti ol2e of saicl chambei-s for deteri-iii--,il.i-ig opei@- a'uioii of tlie main pneiin-iatic, aii ,iuxiliar y pneun-iatic in @aiiother chamber, slid auxiliarv piieun-iatic havii-ig It stem, @,,nd a ATalve actuable by said steiii for adinit'cing Itliiospheric air to sqid 1,,itter chamber. 23. A po-wer controller for tise in a pneiiiiiatic despatel-i systeiii of the vacuun-i ty pe having a traiisntissioii t-Libe, iii e:@zh,,Luster connected therewith aiid a Aalve for controlling carrier pro ellino-@air flow throuo-h the p s nt inprising ,t tube, aid c6 roller co main

13 pnetilii,,itic connected to the vpli7(,, for operating the latter, a casilig havi,,i(y ooi-niiiuiiicatin,(- eh,,in-ibers, oiie at least of saicl el-iaiiibers coiiiiiiuiiicatin- ivith the transiiiission tlibe, a n-iec-,ns respoiisia-e to ress-Lire fluettiation iii p oiie of siid chai-iibers for cletcrriiining operatiol-L Of the maiii piie-Liiiiatic, aii ,iLixiliary piieilinatic in anotl-ier chai-iiber, said auxili,,ir3; pneti,^ja,(itic hzii7ino; ,i SLeiii, a eylilldi.ic-,tl 10 o-uide extendiiig Lip-w,,irdly from tl-ie latter chamber, ,iiid a sleeve valve sliding in said guide, said valve haviiig a port in its -Lipper end, the, end of the stein of the @tuxiliary piietiiii(itic iioi-iiiaII3, closilig said port. is 24. A power controller,for use iii ,i piieuillatic despatch system of tl-ie vacutim type havino,- a ti@ansiiiission tlibe, an exhauster connected there-with aiad a valve for controlling carriel- propelliiio- air floiv tlirough tl-ie -ig a -naii). 20 tube saict controller coiiaprisii pnel-iniatic coniiected to the valve for oper,itij-io- the latter, a casina h,,tviiio- coini-.iunizn p c,itiit(y clian-ibers, one at least oi said chaiiibers coiiimlii-iicating ii,ith the transillissioii Es tiibe, ineans 1'esponsive to pressure fliictLi,,ttioii in oie of said chambers for coi-itrolliiig operation of the main piieuiii-,tic, an auxili@ti@y :)neuliiatic in aiiother cliamber, saicl allxili@ 'Iry pneuiiittic liaving a stem, a cylinso drical sleeve v,alve iioriiially supported b3, said steiii, said valve liaving a port in 'ts end riormatly closed by the end of the sten-i, and a spring for restoring thle auxiliary, pneuiii,@itic to iorii-ial positioii -ifter being lifteci by dif@'erential pressui-es -,it its opposi@e si(les. 35 9,5. A power coiitroller for iise in -t pneum,,itic despateli svstem of the iacutiiii t-,.ype liaviii(r ,t ti-aiisn-iission t-Libe, an exbaiistep n coniiected tliei-eivith ,tlld a val-ve for coiltrolling c,,ii-rier propelling air 'Lloiv throu('ii the 40 tube. s,@il'd controller comprisiiig a i-iiain pneiiinatic connected to the valve for operatiii(, tlip, 1--ttei- a casincy haviiig comiiiiinicatiiicy chambers, oiie at leas'L of saicl ch,,.mbers coii-imi-i@Llic",Ltin,- IA-itli the traiismissioia t-Libel 45 iiie,,,,ns responsiie to pi-esstire fliletuitioil in one of said chainbers for clcteriiiini.i-ir oper-,itioii of tl@ie maiii pnetilliatic, all alixiliary pi-ieuniatic iii ,inotlier chamber, said auxil1,,iry piieum,-Ltic having a stei-ii, a cylindi-i.cal 50 (YLI'de projecting fi,olii tl-io lqtter ch,,Lliiber, a slee\,e Nalve slidii-ig in soid gtiide, sal(i i,-alve 1-iaving a port in its side -,;@,all norilialiv dispo,,,ed beloiv the end of the gtilde aiid ha@- in -- a secoiid poi@t i.ii its end, the latter port 55 ii.o@-rm,,illy beii-i(y close(I by the end of tlio stem, and a szpn'riiiu for i-estorin the aux9 illarl, pneiiiii,,itic to iiorinal position after beiDg by differential pi-essures upoii its bpposite sides, the sleeve valve bein(,Y re- 60 stored to norriial position by the action of g,,-,,Lii 'ty. Sig@ed bv iiie at SyracLise, N. Y., tllis tiveiity-third d,-Ly of M,,trch, 1925. FRANK B.. PEEBLES.

Patented Nov. 30, 1926. 116:0@9@1123 E" UNIT,.D' S@TATES PATENT OFIFICE. FRANX B. PEEBLF,,S, 0,F OYRAC" CJSE, NEW' YOR;K, A@SIC-NOR TO THE LAX$ON.COMPANY, OF SYRACUSX, :D@EW A COR'@;IORAT'-@01,1 OFTYIASSACIITJSETTS. POWEP. CONTROLLER. Applica-tion filed YLareli This inveiition pertains to powei- co-ntrollers for lineuinitic clespatch systeins aiicl relates ii-ioi-e particularly to automlitically actin(y Conti-ollers of tl-ie,@so-ca@ll,-d iiiiniiiium flow p t3, e of wliieli the patent 7to Libby No. 968,578 August 30, 1910, @fui-nishes ,tn o,,trly example. Controllers of this @type coniprise esseiitiv,llv 9, valve, @hereinaf-,,ter @referred to ;as the ii'lain italve" ;located betnveen the transmi Ssiol'i tiibe and aii @,Iir exhttister or vacuum druiyi sucli %,a,lve iiormally c@tting off cari@ie,r ]@3i,opel,ling a,ir @floNA, ihroug,h tl-io tube whei-i the ttibe is idle, ilthou(,@h tligre is tt il@ll times It cojitinuolis flow of- air of - 1@iuall i!oluia-io thi,ouo-h tl-ic, traiisiiiission ttibe, 11.1-,Iifficient to @p"ropel a c,@trrier and k-iio-@-,ii is til minin-ii@iiil floiv", and a I)neuiiiatic, I-or ex,iinple t piston 01, diaplii@A,gm. wl-iieli responds eit-lier dii-.c@ctly or inclii@ectly to eli,tiiges i,n pi@e,stire in ithe, ttibe due to tl-ie ii-ioli-i6ntary ciittiiao- off oi, cheel@in(y of ;the tn iiiiiiiiiiula-i flow of aii- @incident ;to tRe i.-iserti6i@i of a carrier in tlie ttibe, ancl wh,!,cli by i!c@,ison of slich itsponse ol)@ns wide -tlie i-ii,,,iin i,-ItIN,e to I)ei-iiiit ca.1-rierpi-opcll'no- f-'i(@v I , " tlii@oti(-Ii the ti-ansiiiis.-ion ttibe. Tri the foriii of app,-,i,.ttus -dtse,.@ibecl @i,ii Libby patciit the pei-iod di-ii-ino- ivliieli the "(k i-el-iiiii-is open is :determiiied @solely by the ope-r-ation of a t,,Il'ling device. The prose@it invei@iioii is intended to im rove tlio p oper,,ition of a deirice of this eileral type ID 9 y eliniin(,itin-, tlle tiiiiii-io, deiice, aiicl in pl,,ice tlielieof pi,ovictinc, ilicaiis iili;cll resi)oiids dii.@ectly to tli(, cha;ffe of pi,essui-e ii -i the traiisI-nissioia ittibe iiicideiit to dischargo of tlie last cai-rie,r thei,e@-rom for iiiitiatin closure of 9 the iii, ,tj,n vali,e. Svsten-is of the abovb type axe o@ 4@i @l'ten qtiii-ed to iioitl@ uncler verv aclverz-@e con@clitions. For e.xti@il.)Ie, t ' lie e.@Kh.auster To.r pi-odticin(, the -\,aciiu@li-i jilay slo-"7 down, or by i,eason o-f ao,(,, or lcieli: of a-ttentioi-i intiy I)e coiaic, iiicapLibIc@ of n-ia'ntainii-ig t@lie i,,,i,etiiiiii foll, which the system ivas desio-ne,-Ilt@,-,-@nsli'lissioil ttibe and ot@her ipin@,, as well p ,is teri)-iii-ial valvcs and pipe fittings M,."y dei-elop leaks; -,nd the carriers iiia_), becoi-iie -o ivorn is to fit biit loosely in the tubes. Tli o pi-esent inveiiti on is inteiideci so to iiiil-)rove pow(,r controliells ol' that lk,37pe Aviiiel-i (lel,)o.Tid solely til)oii diffeielnees in -i, @,su,-e for open.in(, aiia closing the ii -i@in 26, -!925. Serial No. 18,468. vtlve as t6 niake tlienl reliable aiid certain 55 ill oper,,ttion ei,ei-i for extonded periods of use when@,appliecl to systeiias iii ivhlch one cause or another the iaciiui-n fiLic'(,Liates irre(yularly, oi- is below norml]. l@ clesi'o,.ui lily . iiiiproved controllei I C) lilite endeai@01-liecl to eliiiiinate coiiiplict,e,.l systeiii s of electrical wiring keepiiio, such electri cal ciretilts as are enlployed as :short ancl siniple as possibl.e, and @ilso to iiial@@e the device of compact ancl rugged coiistrziction 65 well able to sustain prolonged ivear. In the accoiupanying drawings a pref-eired eiiibodin-ient is illustrated @ky ivaly @of examp le: I beino- i dilgrainmitic elev,,ttion, 70 in @section, sl-iowing the in-iproved contro ller insttlled betweel'i one transliiission tube of ,t pneul-ilatic sys,ten-i and @the exh,,iust header thereof; Fi . 2 is a plai-i viciv to lar(lyer scale of the 7,,) 9 iinproved po-",er control-ler, th.e trc-tnsli-lission tvibe being shown in section; Fio -. 3 is a side elovition of the clevice ;as ),iew @d from ttie i-igl)t side of F.ig. -2; Lngles 80 to a side eleaation at riglit ig and,partlv in section oii the @line 4-4 of the litter figure, the par-ts @bei,iioshown iTI their nori-nal I)ositioii i@ith the iiiain valve closed. Fig. 5 is a view siiiiilar to@,Fig. 4- ibut sboi,-- @i5 iiig the main valve open; Fig. 6 is a fraoiiientar.), vertical section substintially on the line 6 of Ficy 2'sliow.. -ing the auxiliary cont,'@olling devices for cletormining oper,@tti6n of the iiliaiii valve Fig. 7 is a diao-i-,ti-iin-i,,ttic vleiv ililistratiiig@ tp the lectrical circuit eii'lployed; r@ig 8 is a view siinil'ar to Fio, 6 blit "Iiie osishowin- the correspondin,(,,r 1:)arts in't .1) tion wtich they assuiiie iiiiiiie,-Iiately aftor 95 insei-tioi-i of a cai-rier in tl-ie transmission tube; Fiy. 9 is a simil,.ir vleia, showin,(,)- tlie' cor-ig p@i ts as they are positi@necl after responclii r the inaiii vllve h,,ts full opeiiedy Fi-s. 10 and 11 are vertictl Section@s, to laruer sc,,tle, illustratij-i cei@tain @g of @the eleinents app-,arin in Fill. 6 blit i@-i .9 difterent operative positions Figl 19- is a side elei,,,iti6n o' ,t sleeve valve @L coiistitlitin@,y an eleinent of the I)i-essiire re(yti1,-, t;@i cl e v i c e a n.d l), is a fr, Lgiiieiitai, horizontal see9 y

tion showino, details of a bleecler valve foriuing a part of the inltiii motor iiiechanisn-i. Referriiig to the clrawiiigs and particularly 'Lo Fig. 1, the iiui-iieral 1 indicates a portion of -a ceiltral station desk provided with the clespateli terminal 2 foriiiin(, a part of tli(, sc-,ndiii(y transiiii-,sion tube, 3 leading to -,tii otitlyiiig stat;.on. TliB corresponjing reti-irii transiiiissioii tube 4 is provided with the 't) tistial iioriiially closed del'i,ery tei@iflinal 5 aiid ivitli the extens'lon tube 6 ivliich passes down thi-ougli the top of the desl@ I and is @onnected witli the poiver control apparattis indicated generally by the nuineral 7. A @uc'ion ttibe 8 leads Troni the poiier control apparatus to the usual suction druin oilieader 9 in which a vacuum or low pressure is maintaiiied by i-iieans of a suitable exhalister, not slionvn. A contliiuous air p@tssage or conduit is thiis provided extendi-.ig from the tcrminal 2 to the o7@licLuster, th@-@t portion of tl-ie condiiit proa,i.decl by tubes 3 and 4 foriiiing the tralisn-iission line. The impi-oi,ed I)ower control foi-itiiny the immediate subject matter of 'he present iny,eiition pi-efer.@,bly coinprises ,i, 1-iolloAv c@Lsliig 10 desirably of gelierally cylindrical form ancl open at its opposite ends. One end of this casing is closed by a cover 11 se30 cured in positioii in any desired m,-,nner, and the opposite eiid is closed by a cover 12 of concave form, also reiiiovably secured by aiiy suitable ine,,lns, for e-xample, by the bolts 12a. A partition or septem 13 si-ibstantiall ' y inictway the length of the casing 10 divides the latter into an inlet cliamber 14 ,Lnd ,in outlet chamber 15. The partition 13 is furinislied iaith a valve orifice 16 providin(y comiiilinication between the chambers 14 aiid 15. 40 The side wall of tl-ie casiiig 10 is ftirn;.shecl -witli ,t flange 17 defining an openin(y for the recept@lon of the end of the transinission ti-ibe extension 6 whiel-i opens ii-ito the chamber 14. The Avall 6f the cliamber 15 is also fur45 nished -with aii openinp, defiiied by a flan(,e IS aclapted to receive the -Lip@,er @iid of the suction tube 9, so th,,it tl,.c cliai-iiber'15 is alIA'ays iii coiiimunic,.ition with the exhalister. The chqlnber 14 communicates at all times 50 -with tl-ie cliambei, 15 or the pipe 8 by iiie,-tns of a small 1:),-,sgage s-Licli as m,,ty be furnisliecl by a pipe 20 of small di,,imeer or by a small orifice in the p,@rtition 13. The valve orifice 16 is nori-nally closed by 55 lileans of a valve@ 21 herel.nafter referi-ed to as the "main valve, providecl i-vith -, stem '-)2 slidiiag iii .L suitable (,uicle opening in a spidei@ 23 projectin- f-rom the p-,irtition 13 into the ch,.i.mber 15. TI-@e ialve 21 is nor60 ii-ially lield ,t!xaiiist ils -eat by means of ,i coiiipressioii sprin(y 24 beariil" at one end ,-,(Yainst the cover 11 and at its other ,tgainst the valve 21. A flexible diaphi-agm 9,6 is cl,,in-iped at ;-@'s (5 betiveen the etid 'itange 27 of the casincr 1,609,123 10 and a marginal flange 28 provided upon the cover 12. This cliaphragm thus separaes the chaniber 15 from a chamber 29 ivithin the cover 12. The diaphragn-i is connected to the stem 22 by means of clamping plates 30 70 alid t nlit 31 en(,a(-in(- the tbreaded exti-eiiiity of the s'cili. Moveiiient of the diaphragm to the left tb-Lis retracts the valve 21 froni its seat aiid pel-i,i-iits a free flo-%v.of ,Iir fi-om the transniissioii ttibe 6 tlirough tl-ie cliaiiibers 14 75 aiid 15 to the suction tube S. The chamber 29 coiniiiunicates Avitli the cliaiiibei- 15 by iiieans oT a i-esti-icted passa(re 291- preferably controlled by means of a needle valve 29b. The ii,)I)er -%A7all of tl)e chambei- 29 is ftir- 80 i-ii,"hed with ,t valve orifice 32.normally closed b@y a valve 33 hereinafter referred to as the "auxiliary valve" carried by, or forminc, a pai-t of, the core of a solenoid 34. This soleno'd @s sc,,ctircd to the tipper sup'l@ace of tl)(@ 8,5 cover 12 by n-ieans of bolts 35 and 36,,and is furnishecl -",ith suitable binding posts 3,5- and 36a for the i-eception of the terminals of an electrical circuit hereidafter described. Upon the upper part of the casin,,, 10 aii 90 auxiliary control mechanism is mounted. This auxiliary control inechanisin comprises t-NAo n-ieter cylindei-s 38 and 39 and a regulator cylincler 40 respectively, wl-iich iiaay fori-ri integral p@i-ts of the casing 10 or whi@h may 05 be made separately and mounted upon tl@@ latter in any suitable manner. The cylinder 38 is of somewhat larger diameter than either of the others, and preferably somewhat shorter than the others. Each of - these 1(0 cylinders communicates wi4h the external atmosphere at its loaier eild by iiaeans of a s-Llitable passage, for exaiilple, by mealls of tlle channel 41 extendin(Y ti-irougli the uj)i)er AAall of the c,,ising 10 and lvhich com mtinicates 105 with the respective cylinders by means of ports 42, 43 and 44, Figs. 6, 8 and 9. The upper part of the cylinder 38 communicates wiflh the outer atmosphere by me-,ns of a si-iiall bleeder passa(,@e 38a p' refer,ibly co@-i- 110 trolled b@, an adjustable neeclle valve 38 b. The cylinders 38 and 39 comm-Linicate by ii-teans of q port 45 adjacent to the upper end of the cylindei- 38, and cylinders 39 and 40 commuiiicate by means of a port 46 ,tdjacent 115 to their upper ends. A small pipe 47 or other suitable conduit connects t,he upper p,,trt of the cylinder 40 witli the tr,,tnsmission tub-. or with the chaiiiber 14 of the casing 10, as m,,ty be most convenietit. 120 A I)istoii 48 i-, ,ii,rano"ed to slide Aiith;n tlie, cyl;ncle@- 9,8. This I)istoii is furnished A-viii) a steiyi 49 passii-io- til) till-oll,@@li the closecl to]) of tl)e ev'iiTi(Ter, aiid this @@,teiii is fiii@iiislie(I wit'i ,i fi @@e,,l -@biitji-leiit @,0 formin@-,- a S 15 , lippoi-t 2 foi@ the loiver eiicl of ii, conipi-essioll r)l. A cli-eiilar Ni-asher or aniiular I)la'Le 52 rest,-, ilpon the iipper end of the sl)ril-i,, 51, slidin,,--, fi-cely on the stem 49. Tb,- i-ipper pai-t o'L the steni 49 passes tlirougl-i t (,ulcl@, 130

1,@609,1 3 openii,ig in a bri.clge piece:5,3, iiiouiited upo'n sit])poi-ts 54; This bi@idge piece earl-ies a pair of spacecl contact iilip-iiibers 55 ai-id 56 i-espectii,ell,. -\Nritli whicli itlic washer orpl,,ite s 52 is a@lapi@.d to en@),-aixe wben the pi ton 48 is r,,,,ised. The coiitacts 55 and r)6 ire collii(-cted bir iiieaiis of -Nvires 57 ,iiid 58 to the teri @iial' of @tlic so'@enoid 34, a battery 59 1-1 s (Fig. 7) or otlier stiitable source of elee6ical 10 Leint,, iiiterposed in oiie of these, wires, for ex,@iaiple, the wire 57. A p, @ston 60 is also motinted witliin the cylin(ler 39. This I)istoii is longer tliaii the pistoi-i 48 @ind is relativel.y hetivy, so thit it 15 teiids to retui-n to the loiver pai-t of the c)71.nde.r ivheii il@iised. This piston is provided ii,ith a steiii 61 furiiislied Nvith a ftxed q-1i,otilder-or abuti-iient 62 tipoi-i wliieh a spring 63 rests. An ani-itilar, plate or waslier-64 is sup2U I)orted tipon the up er eiicl of this sprin(y. p The steni or i@od 61 of the piston is guided ii-i ,qn openiiig iii a brido-e piece 65 carried bv s,tiitable s@,ipports 66 ancl 67 aiicl iria,y, if neeessary, be futiiishecl w'jtla an auxiliai-N7 w(,igbt 68 at ts ill)l)er elid. The brid ge piece 65 supl)oi-ts a pair of spaced contacts ('),9 70, respectivelv, witli AAIii.el-i the plate 64 @is ,id@i,ptecl t6 encrage ivheii the piston 60 is 1-aised. The coiitacts 69 and 70 are coiinecte(I by means oi' ),@ires 71 and 72 (Fig. 7) to the -@yij-es ,-)7 in(.1 58 i,esj)cetivelv. A piston 74 is ari-anged to slide wiLIiin the 1.)i,e@@stire regulatoi- cylincler 40. A sprii-i(y ?n 7r) be,,iring at its joiner end ao,ainst the ],)istoll 74 an(i at its encl against the top of the evl'ncler 40 tencls to l(@liaii'l tiie I)iston 74 in tl;@ lo ii@ei- end of the eyliitder. Th(-, eviinder 40 is f-i:trnislied i),itli i cylinclri'c,,il p.tii0@e extelision 76 1,)rojectin@4 from it,,, lip-@O per end, qTid a sleeve v@ili,-e 77 (Fias..10, .Il ,tii(I 12) is -Lri',i,li@zed to slide ivitliin ihis @-riiide extensioi,i. Tliis,sleeve valve,is closed ,it its iii)per end excepL-1 T-or a cent-ral idort or oi-ifice 78, @incl is noi-iiially stipported b), rest45 iii@,y tipon the iil:)per eiid cf the sten-i 7oo of the I.,)iston 74. This slee@i@e valve is @open ,,tt its IoN-@,er end iiicl has a -port 79 in its sicle w,,Lll. Tlii s port is Qf triangtilar or invei!tecl Vs.hal)e, qnd the sleeve valve is iiQitmall)7 SO I)ositione d -th, .tt tllis port is entirely below the upper eiicl 80 of the guicle exteiis;on 76 s slioivi-i ii-i Fi@@- 9. Wlieii the pai!ts ,tre i.ri this position tl@e port 't@ at the end of the sleei7e - N7alve is closed, by the el'.Icl of tlie steiii 73. ,I'Iie oi)ei@,.atio,n of the clevice is @substantial,ly ,is folloias, it beiiig tinclerstoo(I that ii@hen the ti-lipsiiiissio n till)e is idl(, the mai, -\""Ill-e -)I '@S cl(),,,ed. tbe cliaphragm 26 ocetiCJP pies the pg,@ition slio)in in Fi(,. 4 aia(-l tli(,, aiixiliai-y vali,e 3i') is closed. At this ciiiie a jiliiiimlini rloii, of air is entei-,ino@ tl,,e traiisiiii.gsioii terniiiial 2 and passi,@ig tlirou,@4h tile I)i,i-)es 3 ,Liid 4 traverses the 1);!Pe 9-0 on its 05 v @'o the exliatister, When a carrier is insei,ted in the @tr,,tnsiiiiss,@ion tut-,e it obstiticts the IDass,,tae of the iiiinin-iiiin floiv o-'L air, tlius i-esiilting in bilildin@,r u p vaeL,,ui-ii in the cyliiicler 38, and catising 70 the piston 48 to rise'tliereby clos:iig the eir cliit tliro-L@gli the solenoid 34. The ai@ea of the pistoii 48 aiid its Nveight ai,e so cliosen that it tends to rise when subjqet to the ,,ery slightest press,iire Oiecrea,- ,e ii-i the transiliissioii ti-ibe, so that even @thoti!-@li the tiibe leak oi, the cirrier be worii, the piston will rise ivith cei-tain.ty. As sooit as t@he eircu;t throiigli tl-ie solenoicl 34,is con-ipleted tlie coile of the soleiioid rise's, thi-is lifti ng A7alve 3,9) ,ind opeiiiiig the port so 32 to the atli'losphei-e. Atialospheric pi!essure thus lets freely tipo.@l the otiter sicle of the cliaplira@@i-ii 26 aiid as the iniier siae oT the (Ii-pl-ii-a@-in is exposed to the pressure.in @t the stiction ube 8 tlie diapliv@io-iii lI-loVeS 8p i-al)icl'.,v to the left, as i,.iewed in 4. until it igsiiiiies the 1:)osition sliown in Fig. 5 thus ol)eiiiii(v the iiit,,iii valve 21 ai-id perii-litting a ciirrier iii-ipelling iir flo.- kN@ to pass tlirougli ain 09 the transi-iiission ttibe. AlThen @tlie i,alve opeias the vicuuii-i in t-he transi-ii:ssioil ti,it)e ,s ijici,eased ver@ considerably, and as this ITacu,,ii-ii pressulle is ti-,,insn-iitted t'hi-o-Ligli the pi.l)e 4'@, the cyliiidei- 40, ai-id,tlie port 40 to the c,,- Iii-ider 39. t,lie 13iF,,toi.-i 60 rises, clos- 95 ing tlie, port 45,, The pisto,.i 60 is of wei(yht th,,it it cloes not rise iit all Aihe-.-.i the carriei, is first nserted in the ti@ ansli'l'liss,ioi-i t,ul)e aiid before tli,e iiiain i,alie opeiis. ),ITlien the piston 60 rises tiacl closes,the pqrt l'OP 45 it al.so iiioi7es the plate 64 ii-ito eiio-ageiiei-it v;l,tli tl-ie coiitacts (;9 and 70. , , I-ie ii-iovemelit of tlle 1.)iston 60 beiiisi-icli cs to coliapress tlics'pi,ing 63 to @i substaiititl exteii,t. -kfici- the port 45 lias closecl ttie piston 48 105 NV slo Iv cli-ops, since air it atiiiospheric pressure is peri-iitted to bleecl in tl)lloiigli the pqi-t 38@l al'Ld tl-itis the ei-@cu@t tlirouo-li the co,-ntacts r)5 and 56 is br,o,ken, tiltliougli the eircuit tbrotigli ithe solejioi i sti ci . s 'II by ii,o tL-e plate 64 eiig@ging the coiitact.9 69 and.70. The parts i-eii)aiii in this position (Turing tl-,e flig,@it of itlie cari.,- iol, a,,cl, so long ,i s a siiigle caiiriei- iejiia,@ns in tlle transi-Aissloii ttibe. If but o,,io cai-rier be iii,,@er ted ti.ie 115 P a I @LS rem@i iii as clescribed iiiitil this cai,rier -e ei@ier o from the tijbe. AV]ieil this o--ci@,l@s the i)lle@,@sulue @!i-i the tians,-.qissioT) ttibe rises aiicl this 1)(,i@iiiit the -v@eiglited p,is@,@o@ s p@ 0111 60 to cli,o tlius rc-,iiiovii-ig tile,I)Iite 64 fi120 aiid bre 1-1 Cy the coiitacts-69 ,qnd 70 a 'n the eirc,,ilt thi,olig-li the soleiloid. The valle 35 a,,id the @ai.i- is ex, iiausted 'LI!01-11 ro 29a. tiie cliairiber 29 tli ucili the passaoe After a -,,Yery siioi@t ii-iterval tlie pressures 125 i:ipc)n the opl@osite @icles of the diali@liragiii 26 are s6 i-ieai@ly bala@iced tli,@t the sprin(y 24 is il)le to close. the i,ili7e 21 thlis restoril-ig tlle, 1)@,pts to iiiitial ])osition. T 130 -f. duri.,(y the fligl-I,L, Of the first carrier

1,609,123 ?Ile or uiore aclclitional carriers are iiisei-tecl iii the 'Uube, the contact plate 61@' remail'is in eiigagei-iier@t ivith the coiatacts 69 ancl '@O iiiitil 'Uhe last carrier has been eolivered froni the tube. I@s eacli cqrrler einei-(Yes fi,om the tlibe there nia-y- be ,t iyioiiic,,iit@,iy sliglit increase ill pressure Ili the tube, but since the spi@iiig 63 is iiitiall.)T placed iiiider considerable @oliii)ressioii si@eli sli(,@lit fltictuatioii of10 the pi,,@ton C)O as ii-,ay occlir at the delin,ei-y of eaeb carriei-, otlier than the last, is iiisuffici6iit to reiiiove the I)Iate 64 froiii the coiit,tets 69 ai-id 70, ai-id tlius tiie eirci-iit is in,,tillt,,iiiied until the last cayrier is clel:iv15 ered. As above sta'Led LI,@e I)istois -1-8 and 60 are so desigiied a-, to be selisi'L-'Ively i-espoiisive to a rai-i(re of pi-essiii,e-Z sucli as ivould be folind in zn a system iii wliieh a very poor 20 vacuuiii iyas n-iaii-ita;iie@l. Sii-ice t'iiese pistoiis are so seiisitive 'L-o i)resstii-e fllictuation, it is evidei-it that ll;' iiistal',ed ii-i -@ s-- ),steli:i ii-i iA,Iiie-li a high vacuuiti is iii,,tint,,,iined they -\voulcl be ineitectiire for theclesire,-l I)uzl)ose 25 and for tlils reasoii the re(,tilator cyliiicler 40 is provicled. Noriiially the pistoii 74 oceiip,;es the i,--,ositioi-i shoiii-i ii-i Fia. 6 ai-icl the s'leeve valae 77 rests upoii ,i,lid is stil:)ported by the s'Lem 73. 30 Botli poi-ts '@8 ,tiid 79 of the sleeie valve ire thiis closecl. I'L Llie vac-L,.,,im ii-i the system to Avliieh the app,,ir,,)tus is a,,- )l)liecl is gretter - @oi than that T-oi- @vhich the I)is -is 48 anci 60 Nvere desi-iied the pistoi-i '(4 rises in opposi35 tion to the spring 75, thiis liftiiiy the sleeve N,ali,e 77 -Liiitil the upper end of the poit 7() is exi3osed above the top 80 of tl-ic guide i'6. This acii-i-iits aii, to tlie, i-,iterior of the cylinder 40, tlie,,el)y clecrea@.iiig the eitectine 40 A-aciiuiii iii ilie cyl.iiiders 38 aiid 39, al'uhouo-ii fl,,.icti.iatioiis iii I)ressiii@e o-cur iii these cyliridei.@s corr(,spoiidin,,- to the fliietiiations iii t-' pressure iii the ti,ansmiss-"on line, the only difrereiiec beiiio, that the i@aiige of pres@--Lires 45 ill tl-ie cyliii,,Te,,s 38 aiid 39 is lower tliaii that ill the ti-aii9lilissioii tube. if a very hl,u@li -,-aciiiiiiA is maii-itaiiied in the tr,,Lnsmissioi-i ttibe oi@ if ,t large niimber of cti-riers are siiiiult,,ineously inserted, 50 ivliieli hts tlae effect of iiicre,,isin(, the ITacthe sleeve valve 'i'@ iiia@ rise to ,t considerable exteit (Fi(r. 10) ai-id as tl-ie port 79 increases iii inidtli -i'rom its tol.) toavard its bottoli:l, the admissi6ii of air to the cylii-i55 der 40 inerelises i-a-,)icll),, so that the de'siiled presstire ii-i the cylinciers 38 ancl 39 may readily be iiiailitaiiiecl under all coiiditions. I-' diii-ii-io- the ope,.ation of the al)ptratus, 60 the ql(,.eve valATe lias beeii liftecl, the clelivery o-f " the last cari-ier froiici the traiisii-lissioii ttibe ",Ith its conseqiiert iiici-ease ii-i I)Pessijre ii-i the latter tends to I)ei@mit the I)istoii 74 to return rapidlv to its Doi-ii:ial positioii. 65 If the sleeve valv@' 77 -\vere closecl quicl,-Iy UDder stieli eirei-iinE@tai-ices, t-'Lie -@iet result n-iiglit be that the pi-esstire in the cylii-ider 39, insteacl of increasiiig to permit the pistoia 60 to clrop, would actually deci-ease the result that the circuit tlirou--li the soleiioid ivoulcl iiot be brokeii. To ,uvoi(,l this 70 actioii the ])ort 78 is pi-ov'jded aiid -\vlier, the pistoii 14 di@ops siiddeilly, upoil delivei-y ol.' the last carrlei-, tlic, steiii 7'0' of the pistoii iilov, es f i oiii the pol-t i'S (Fig. II) anl tlil,.s perj)iits fi,ee enti-aiiee of air into tlle 75 cylilider 40, so tli,,it inei-ease ir. pi-essiil-(@ iii the 39 is cei-ta;n. the pistoii 'i4 lias returii(,cl to -its jio-,.-iiial I)ositoii the sloe-,-e N,ali,-c, 77 ffi-aclually retuiiis to ii@s i,.oi,- i-,,o@--ittoii 'L)y ti-ie actloii olf' so 80 tliit the p@Li,ts ai@(@ i-estoi-ed to theii- iiiitial positioii. Wllile I 1,@,i,ve slion-vn P"ISLODS Avori@ill(,. in as the auxiliai@y co.-itrollillo, ageiits as as the I)ressure regulatii-ig nieaiis, 1 85 coi'eiripl@,-tte, 'Llia'L olher Torn-iP, oll piieuii:iat@le inotor, sucli for example, as diaplii,agi,.s d@sI)osed in si@tita-ble casiil('s ia-iiy be si-ibstittitecl @@@or the pistoiis here sholvil, ivitil s@och cor-,,espoiidii)g chaiio-es iii details as iniglit be 90 necessary iii i-iiaf@:inci sucli siibstitutiolis. I also conteiiiplate that the iiiain eliapi-ira-iii 26 mav lie replaced by a pistoii or otier fo,--M oi':' motor, aiicl th,,it t'iie various I)ats constitu't,'Ing the col-itrolling apl)aj.,.ttLis .,,s a wl-iole iyiay be difterelitly arrai-iged alicl difTel-eiitly prol)ortiloned ,is eircumstaiices i.-ia-,T i-vai-paiit. It is also to be iii-iderstood tliat the I)i-essure mutilating me,,ins comprisipg the cyl100 irider 40 oi- its eqtiiNTaleiit iii,-Ly be eml)lovel ii-i othe,,, ei-tviro-@iiiier@ts and 'li-i colillec:. u]Oll ivith other 1:)o-,ver coiatrol apl)ai-attis I)ti,L that herein specifically illustral,-ed. I