4 1,840,718 ,ilso formed on the are of a eirel h,,tving the pivotal axis of tl-ie holder as its cenier. In Fig. 9 a series of individ-Li,,tl ibrading L,,,trs Ill 112, 113 are shown, wliieh are ol! ii-regtilar cross-sectional form and have spacin- strips 114 tberebetweeii. These individu abridi-ng b,,trs comp@rise slanting abrading eclges 11 1 5. This nest o' ii-idividual abr--dIn b,,irs also has its abrading end on a, simi9 10 lar are to the oth--r forms shov,,n. The nest ol-L'- individlial abradiiig ba@-s are clamped in the holder in rjaaniier simil,,ir to the other ,9,brading btrs shown and @iescribed. Fi-. 10 rel,)i-esei-its a nes'@- of ind;.vid-aal 15 ,tbrp@ding b,,trs 118 rectangi-il,,tr in cross-seetion, s-,)-.teed apart by spacing strips 119, and preseiitecl flq tNv-1 --e to the grindin surface of the griiidin- \iheel. The nest of individual abrading bars is elfti-nped iii the holcler in 20 manner siiiiila'r to the ot-@@er abi,adino- b,,irs sl-ioin,n and described. The abrading end of this nest of abradina bgrs is also shonvn on 11 Silililar are. 25 The individual abrading bars of the res;pective foriiis may be ac.Ijusted lenvthwise ,,Iop.g the s aciii e p _g strips ,ind. in th holder to tal@:e iip wcar ,tnd to maiiitctiii the ircuate forli-i o-'L' the abi-,,tdiug end. O-Lir iinproved device is S;-mple in coiisf'ruetion, provides an economical abrading means for 'Uhe grinding ivheel, ,t--qd is exceptiona,lly e,ffective in trlii-ng and @Lres-,- .,,ag grinding wheels.. HaiTin(y thiis fully described our invention A-Vhat we claim a,s new, and desir@e to sectire by Letters P-,ttent ' is: Iii iiieciiinism for triiing and clressing composite @,yr.-IidiD.(y inheels, the coinbiiiati(n witl@ t,he @rindin@ wheel.' of a con-iposite 40 !Z abr,iding bar liaving a tex' Ure harder and u coarser thaii the texttire of s-,tid grincling ivheel, iiieans for pivotally supporting said abradinv bar for presentin" its end to sai(-I@ .rindii-i@7 -\i,heel, said presented end being of arcuate form, and -iiieans whereby t6 6scill.ite saicl abracling bar on its pivot for moving the areti,,ite end of said ,tbrading tool ,i,cross tl-ie grindina -wheel Avhile iii contact wit.h t.he uriiading wheel calisino, it to trav50 el erse the @rindin(y surface of saicl o-rinOLin .9 wheel in cpposite directions in arcu,,tte paths to tl-iereby cle,,Ln and sharpen said grirlding surface. 2. In n-iechap-;.sm for trtiin- and dressing 55 co,uposite grincling wheels, the combinauion tl-ie grincling -wheel, of a composite al)r,.i(lin@ bar having@ ,i texture harder and cog.rser than tlie texture of said ffrinding Avlieel, iaea-tis for piiotally su-p orting s,,iid 60 p ,ib,-adiii,2@ bar for presi@,ntiiip, its end to said,,rindiiio@ -wheel, sa.id pr sented end being of fo,7m, alnd autom,,ttic means whereby 4-o aiitomatic,, . illi, oscill-,tte s,,ticl ,ibrading b,,tr oil its pi,vot f or moving the arcuate end of said abrading tool across the griiiding wheel 1 n in co-ntact w'th the gri ding wlieel for causino@ it to traverse the grinding surf ace of said grindin(r wheel in opposite direc'ions in ,ireua,te pa@hs to tliereby clean ancl sh,,trpen said griiidinsurf ace. 3. In mechanism for truin- an(I dressin(, composite o-rinding wheels, tfie combillation -,vith the g-rinding wheel, of a composite -,br,,idino- bar h,,tving an arc7Liate abrading end 1-@ and having a texture harder anci coarser than the texture of said grindin(, Nvheel, means f or pivot,,illy supporting said abrading bar f or I)resentin- stid are-Liate end to said griiidin- wheel, aiitornatic metns f or oscillating r catising sai slid Ibrading bir fo 'd ,trcuafle so end to traverse the urinding surface of said grindin- wheel in opposite directions for rotI'Uin.g sai-d are-Liaf'e end of sai-d abr,-Lding bar ccross the grinding f ace of the -@,rrinding whe-.1 in opposite directions in contpc'L-1 with s,,ticl B@ grincl;ng surf ace to thereby clean ,tnd sharpen said o;rindin o- surf ac@e, ,Lnd means whereby to position siid abrading bar out of range with said grinding wheel. 4. li-i mechanism f or truing aiid dress!-ng coiiip6site g-rindin,,(,, ivheels, the coinbin,,ition iiith the -ril-iding wheel of a coinposite abra@.@@in!x b-,ir of subst-,intially 1,,trge cross-seetioii -ncl haiing a textiire harder anci coarser th-.tn the textu,,-e of sai(I crri-,n-diilg -wheel ancl of sueb teiiac,,ty -s to enible a I-)rotr,,Idin- enci 6T. -,aid abradinu b,,tr to unsuT,)I?ortingly -withs'Land tb.e lateral stresses of its abrading action oii said gri-ncling, WI-ioel, means for rele,,tsably suppoi-t-Lng @aicl ,ibradina bar in manper to T)rovicle @uch T,)rotruding abra(lin,o,end apcl comprisin(r me,,tns for end",ise adiiistmenLI of gllicl abrading bar with rel,-,tioii to the grincling surface of stid grinclill(T rn Nvi-ieel, s,,iid @ibr-,,,ding bar provided with an io5 ,trcua+,e eiio, abradinl,7 f,,ice ,trrangecl -,or abrading en-auen-ient -with saict grinclna wlieel, and T@e@'ns for pivotallv supportin'g said s-Lipliortino; i-neaiis whereby to oscill-,).te said -,ircilate etid abrqdin(- face of s,,,-id ,tbrad- 110 ing bqr fo.- ci,iising its a,-,C-Liate encl to traverse said grind; ng surface of said gri--Qding -wheel in opposite dire;--tions for oleanin and sharpenino- saic.1 urinding si-irf ace. r). Tn. meeb,@nism f-or truin,,(@ and dressine, 1composite (Yrindirig wbeels, t]@-e coi--qbidation of a co-mposite ,ibr,,tdin,@z bar h.,@ivinz ,t textlire h,,ircler and coarser than f@he textlire o'L saicl rindit-ig ivhcel aiid being of siibst@,tntiall@l 9 larue cross-sect,.op, t holder f 6rsaid abrldip 120 @),,ir arrgn-ed,, for hol-dinfl@ slid I,bradin- bar ,i(-Ii (-, bar protrudwith tl-ie e-nd of s,,iicl abr, -.q, ing-, therefrom toward spicl !@rinclin,(@ -@vheel. said -bradin@,Y bar bein.(Y o-11 sLibstint;.,Illl, @n 1,,trge cross-section of sueb tenle-ity as to 121e,n,,ibl.e gaid i)rotrticlincr eD-(l of sail abradii (Y 1:),,@r to -Li-nstiT)portino:ly wittistand the laterf-,,l stresses of its abrading@ - tetion on s,,iicl g'rilicling ivbeel, saicl ,tbracling@ bai, T)rovid.-,,,l ",itb an arcuate erid ,tbrading face coacting@with oo 90- -100

1,840,718 aid d' s ' grin mg wheel, a bracket, means for adjustably supporting said bracket on the worksuppo@rting table of the grinding machine, a st-Lib on said bracket mean pi.voting said holder to said stub, means adjustably positioning said stub on said bracke-t for adjustment of said abrading bar with relation to the rindino, surf ace of said grinding wheel a motor on said bracket, a reciprcicating li@i 10 betweeii said motor and @said holder, constructed and arranged for oscillatiiag said ,trcuat e d in an arcuate path across the n grinding face of said --rinding wheel, means releasably connecting@said link with said 15 inotor, and means releasably positioning said li-nk so located as to swing said holder on its piv6t,for positionidff said' abrading bar out of range with said grinding wheel. m In testi ony whereof we have, hereuntb 20 siomed our names FERDIINAND J-. HOHNHORST. FERDINAND J. KROEGEA R. 25 30 35 40 45 to 55 60

Patented Jan. 12, 1932 1 , 8 4 0 7 1 8 @ UNITED STATES PATENT OFFICE FERDINAND IT. HOHNHORST ANI) PERDINA.ND T. KROEGER, OF COVINGTON, KFNTUCE:Y NECHATISX FOR TRUING AND DRESSING C--RII@TDING WMEELS ApplicationfiledApril2O,l929. Se rialNo.-356,806. Our invention telates to mechanism for trlll'ng ancl dressing grindin-cr -wheels, su6h as ee-iery wheels, c@iilployed ii@ machiner. I f or y, grinding br poli hing surfaces of metal in precision grinding. Aii example of mechanism of this chara6ter is shown and d6scribed in Patent No. 1 544,985, olranted us on July 7, 1925, for I inechani@@for truin(y and dressin-a L@rinding 10 ",heels. The grinding whe6ls em-Dloved in zrinding n 1--qet,ils:and similar hard s@bsia ces, which it is the object of our improved device to opcrate on, are coinposite d'n , -wheels con15 taiiiingc6mmint[ted or ffr (e,@ly'di'vided em ery, carborundlim or other cutting Imedium@ and a suitable b6nd, suitably bound together as a, 0 con,lposite mass, the fineness4 f the -rains of the c,,it@in& i'lledium being determined by the 20 coarseness or fineness of the grinding which is to be done. It is essential in precision grindi@g that the grinding wheels shall be maintained in their true f-orm for instance (,,ylindrical form. 1 25 It is the object of our invention to provide liovel means for truing oi- dressino, the grindino@ surface of the grinding wheel; further, to provide a composite abrading bar aiad means whereby to present the, abrading bai 30 t s-Lirf a6e of th 0 the &rinding,, e grinding n wheel; further, to provide means for traverse between said abrading bar and said - rinding siirface for cleaning, and sharpening said nding siirface by means of said abradiii -gar"; further, to p r provide a corn osite abraling bar having a texture harder and coarset th@in the texturc,, Of the gi-in(ling wheel c,' wli-'eh it aefs,@ and to provide a composite ,ib , rading bat containin-, grains of emery, carborundum @ or other@ cutting - medium, -Nvhich are harder and coarser than the grains o--F the cutting. mediums in the grindina wheel 5 and stitably bound to(yether by a, sui+u,qble bond in suitable mannei. to form th45 coi e of the abrading bar ttle iip6site structur 'L,olld in tiie abradihg bar being more resistent to disttirbance, or to reloase of the grain@s oT cuttingn-iediu,n-ls thereiii than is tl-ip- bond in, ibhe g@indiiig . Nvheel, so as to@ provid-- an --ibrad' ing bar @which is more resistant to wear than ihe grinding wheel @and which has a cutti@g a,et@@on on, the grinding wheel. it I n urth to s the qbject of our inventi6 f er ovide n6vel meciias for supporting the Pr abradi ng bar'for presenting. the s:ime end- ,15 wise 'Lo the (_Yrinding surf ace of the grinding whbel, and@ -novel @meat!s whereby to oscillate said abradin ba @for cau g r sing its end to traverse the grinding surface 6f the grin ino; wheel in opposite directions t6 clean and 60 sha,rpen said gtilidiiig surface. -ie It is tl obj@et of otir inventi6n further to provide a pluralitv of 'abiading bars arr,,tnge d parallel with e,ach otlier in nested -relation for simultaiieous presentation of their 65 @nds to the grinding stirf ace of the grindin@ wheel; and, further, to space the individufil aid ilest of @abifrom each oth6r f 6r ore8entiiig t,hel edo,,es of the abradin end a said @respective . indi-@ 7'0 9 vidtial abradink bars to the grinding wheel for iiidividual @And simultari@ou @ action on said grinding surface. Th4 a inventi6n will be further roadily @ndersto od from the followii,io, description aild 79 claims , q nd fr6ni the dra@wings, in which- latter: F i @o-,. I i s a, side elevaticii of our improved device ,@ MoLinted iii a zriiidiiil)' iliacliine and showi ng p er ' ans for oscillating the ow me 50 abradi no- bar the o-rinding nlachine being shown partly in section a4d partly brolien ,Iwav. Fig. 2 is@@ a plan vielw of @our improved 85 d6vice . Fiu s 9 imp ved 3 i a, ide elevati6n of our r6 device showing manual s for oscill I mean ating the abrading bar. Fig@. 4 i . a cross-section of our. im:)roved - $ l@ 00 dei7ice, taken on the line 4---@4,of Fig. 1. . Fio,. 5 i@ a cross-section of the, same @ taken I n p in the plane of the line li-5 of Fi@. 4. . -Fig. 6 is a perspective view showing an abradino, bar coi-nprisiii s-paced nested, '@n- os 9 dividual abrading bars.. Fiu. 7 is a cros -section of the same taken on the -line 7@7 of Fig. 6; and,, Figs. 8@ 9 and@ 10 are perspective:vie-t-k -iz@@a rading ba rs compri showii b sinl), Dac.,)d loo abradin' o, bars in @ s I I ading b@rs

iies'Lecl ir.-cliv;_dual a-brading bars of other cross-se(@tional forms aiid arraiigements. Tiie o'-pincliii(v machiiie may be of any den sirc,d kl--Licl, and may for i,,lst@tiiee coi,-ipris,fraiiie 11, on Aihich there is a 12, aclju.s"-abl(, in siii-t,---bl-, iiianiier upeii the fr.Liic,, a-,@ic', sui,)I@@oriiii(@ q, griiiding wheel 13 in suitable b@ariii(,s'on the slide. -Lhe wi-ieel is iiistancea' as rota'Llii-ig iii tl-ie directio,.i of the arrow (t. -i prac@ice % The ariji@din- wheel 13 is ,i 0 - iprising c iiildosice Q:rindinu wheel, coii LI i-,@iins OT emery, carl.)orundiii-ii or 6ther cuttliig di@iim oi t@.ie desii,eo, etegree of ecprseiiess or fipeii--ss dependin(y on the coarseness or fi-Tie@iess of tile griiicliiig which i-s to be Derf oriiied the -ra--.iis of cut'@-,,.ng medi-Liin beilll(,I)oLincl together bv @i suitable boiid in suitable m-,nner or bysliit,,tble process for forni,20 'LD,(,, a liard composite grincliiig Nvheel. A saddle 1-1 is slicl,-,ble on -UidewaAs '@5, 16, oi-i the fran-ie, ancl @'s GI)ei,,ible by me,-Liis of ' 'i @ ith which ,t plp,;oii 18, suitabiy a rac,-, 1 , Ni,- @ I clriveii, mesl,.es, for pi@ovi-diiig --,Liitabl.e ei-icl. 2r, Niise -ieed be'Lween the -y@,orl@ oi- the b-,r 19 ,tiici the ariiiding ivheel 13, this endnii-se feecl may be obtainecl b)T eid-",ise iiiovement of the griiiding -v@hee . I Nv i-tl-i relatio-Li to tl-ie work or il-ie. abradino- bar. so Stiel-i clectioii of endwise feed of the work or the griiidiii- ivheel is explaii-.ed iii our afore@ n said patent. The work-suiiportiiig t,,ible 21 is pivoted by a i)ivot 29, on the sa-ddle 14. TI-ils worl@@35 supportino; table h,,is thereoii the heact ce,@iter ard t,,ii.1 center, be',- IVeel-.l Nvhich the NN,ork is supl)orted, as explained i,,i our i--@oresaicl patent. The abraotin ,g bir cont,,tins gr,,ti-ns ol e@-n40 erv, carborui,,diiiti or other c,-Littin al'i ul lie w@ich are hai-cler aD.d co,-,rser ' -i ,rains of cuttip-g i-ne,,Iil-iin iii the emery @vhe,-l oii wliieh the abr,,iclidg b@-.r acts, aii(-l tlio tex'@tire of tl-io, abrading bar is h-,ircler than the tex4l-ur(i 45 of the grindiiig -",heel on ivhich 'the ,ibradi-ao, bar acts. t, 'rl-ie abr,,tding bar is a composi-te bar comprisi-ng such l@,,trder and coa ser grain,-, ancl ,It sllitabl-, boiid bouncl. 'Lo(,Yether as a combo posite mass iii siiitable mat-iiier or by suiil-able process and formi-ng a composite mass h,,Vii-io@ a t6xttir@ harcler and coarser th.-n the texttire of tbe -rinding -wheel. 'I'l-ie abradinr bar is shoia,-n ,)rese-@ited -,vi'ub 55 its end tb-ward tl@e arindin stirfqce of tli(, 9 grindi-ng ivheel. It is preferably (,i' quite h,trge cross-sectiopal area, so that P, i)rotrticl I iiio, ei-id of an abr,,ieling ii-iay successiLil-1. ),@vithst,,ii-id the side stresses to wliieh th,@ 6o abradii-ig b,,ir is subjectod in tb-e t,i--Lii,,-ig oi, dressin('- operation ii o-i th@ griii4irp, ,ihe,-I@ zn p The gi-indin(r -@i,heel diirin(_y cperition be comes iinpreg@-i,,ted Avitli paelicies of diist, dirt or inetal from @l-he ivork being oi)era't-,ed on, and beco@iies comi)aratively gloss , tnd y 1,840,718 thereby loses its (yriiidi)i- effect, its granula,l@ -.triiettire also becomi-nl- dull at the arip-diig f ace, thereby re-juchig its grindinu or po'@@isiizn Lnl- properties. -t"he Pbr,,irj;iig ba.- to remove such I)ar70 t;.eles of- 0,,-List, dirt a.-I,-l metal out of the grincling alid 'ilo roug'iien and shp..rp-n the uu gi-,qii.ulai7 strtic' re of the rincling f ace. 9 The ,ib-,@aclijig bai- f Lirthei: acts upon said gri.ndinc,- face in opposit,- directions by '@nov- 7r, inc, tiierbover iii o-I)p6site directio.-is frict;o-iially actiiig ol-i the clirt ,Lncl par'Llicies of apcl other foreign substances in 'Llhe interst;lces o-I s,,ticl gr,,n-,Ii-ng sui-f,,Lce 1-n oi,-)posi'ile dii-ect'o,,is to @,ig ou-, such foreign siibscaiiees So and to iiiore ef@e,-tivc". @y .harpen the grgiiis of tlip stci:@,,@@ure of saicl grindid(, s-Liriace. The abrgd;-iig 1),,@r is oscill,,iled for the purpose, Tl,.e -,bra(!!- ,nlu b-,tr is shown suppo.-te(i s,5 iii,,i hol-cler 25, Nviiiel-i -is provi-ded with a clia-.1- iiel 2,6, @vhich e,-@-teiiOLs throiio;h the bocly 2i of the holde,. anci ip- i,7hich the abrading b,-,@.@ is ree-,I,,,-ed. A claiiip-p'Late 28 is clamped upon 4 - e 't,lie abi-a(,in,)- i:)a-r I)y means of bols 29, r ceived tlirou@,,Yli liol.es 30 in 'Lhe aiid in4,,o tlircacled holes 31 in the bocly. r@, abr,,t(lin@- b-ii, ,he Pb)!ading et-id 35 of the extends fron-i i@i-ie holder to-,varcl 'ulie (yrin,,Ii.ng wheel ' The abracling bar n-i,,iy a!-so eL- 05 tenct reprwirclly . o,,-it of the 1-iolcler, as i-.qdicotecl by the re,,Lrwarclly extencling end 36 tliereof. The abradi-@ig bar may fron-i ti.me to time be aCij-Listed lengthwise in the holder as the abradiiig end thereof is shortenecl by iou wear. A stub 41 exteiids from a bricket 42, the hol,,Ier bei-.,ig shov.7T-i pivot,,Lll-y -,(nounted o-ii b t@',ie stub. This pivo-al inou-,iting is sho-wia by iiie,,ins of b,,,,Il-be,,tri!lgs 43, 44, receivecl jrii th 1 ih abo-Lit ' (,, stub 'i) a re,-ess 45 in '- e holder. The ball-beai-iii-S are preferab".- oppositely @ - I y clispose(I nidial and onct thrils@-, bell-bearin(-s. The -iiiner rleewiys 46 of the ball-b-,arill(ys are positione.-I in -ep,-t-i.-ated relation by ,I iio coll-,tr 47 ftyed as by p-ins 50, on the stiib. The ou'Ler racewtys 48 of the ball-bearings are seE,,,trated by ti, I)usliing 49 in the recess. The outer r,,tee-xvays wi@Llh the btishit-ig tl-ierebetiyeen ,ire in the recess b3, means ii5 of ,t plug 51, Qcre,,i-ed into E@ 't,',ireaded recos:@ 52 in ti-ie holder, aoainst aii ann-Lilar shoulder 53. The ,ibrading bar is thus pivot-,till,, iiaotinted, ,tyid the liolcler is seclirely helcl erally oD tb.e stilb. 1 2 0 T'jiie stlib is ,tdjustab'le on the, bracket, as by h,-t-,,iiig sh,,tnk 55 receivecl in t,, sl,)t 56 !D the br,,i-!< t,. Viie o,,)pos-' e s'des oy' ti-i-e e t S'i-iarik, Nvhich cogct wi@l-h tfie sides ol' I'@l-le o'L th(, sj',olt-,, ,@re 'It't-e-qecl a,@ at 54. There 125 a collir 5'@ ope cnC@, of the sha-- Qi@, a iiii,@ I I is threadecl: over threaded reduced ei).c@ 59 ,t the other of the shanic, aiicl claml).i Ciie shatik to the brocket betwee'n the co-,.'.Pr and a Nvasher @60 130 clamped by the nut.

1,8401718 The bracket is e6urecl to the table 21. The bracki@t is provided with an arm 61 whieb h,ts a iaw 69, thereon coactinly with a guid(3 63 on tl-ie table 21. The table is provide(] with a rail 64, and the bracket,is pro-@idecl with a clamping face 65. A cltimi)-@i,@ce..66 is loo 61y. connected @with the head., A threaded sttid 67 extends @ fronl @ the, brackelt, thro.ugh a hole, in the clamp-piece tnd has a 10 claml)ing:: nut 68 thrbaded thereover, ior clan-iping the br,,teket to the table at desirable points ,tlang the'rail. The holder of the abrading bar is arrangeci to be oscillated for causing traverse bet@,cen' 15 the end of the abrading bar and the @grin I ding wheel@ The abrading end-face of the abrading bar is shown formed on an are Oe scribed from,the axis' of the stub as@ its center. TI-ietra-versingmovementis@shownas@i,,,l 20 the direction of tl-ie' pj,,tne. of the grindina wheel but.may be@ at any angle thereto. ALitomatic I means !or @se-illafin(y tho abr,,tding bar m-,ty be provided'and an example of same is shown in Figs. I and 2. 25 @ In this form a shank 71 extends from the holder 25 baing showii screw-threaded at '72 totheelam-D-Dlat,e28. Anelectriemotor@73 ig fixed on tho btqoket.-: A worm 74 is o.- ,i the motor shaft, qnd meshes with a wollm30 wheel 75. The worm-wheel is on a shaft 7C) I ournaled in a bearing 77 on the bracket, apd has a crank-wheel 78 thereon, provided wit'@@-i a, crank-pin 79. : One en.d of a. link 80 is arti.6ulated at 81 with the shank 7.1. The. link ic@ idii provided with a fork 82 at its,6tli@r end.: received over the crank-I)iii @9.- The link may be disconnected from its soiirce of power when -it is desired to -place the abrading bar out of iise. This is accom40 plished by pron,iding said fork for permitting r,eady release @between the operating end o@f the link and the crank-pin. The link is provided with a handle 85 b ivhich i.t, inay be raised so is to move the 45 walls of the slot in the. forli: away from the crank-pin, and, for instance, place th6 fork a,bout a pin 86 on a bracket 87 extendin-- from the bearing 77. The holder for the ab@@ding bar is thus swung rearwardly.on its pivot 50 for swin 'n- the abrading end 35 of the 91 abrading bar upwardly out of rolnge with the grinding wheel. If it is desired to a-ain operate the abrad-ing bar the link is released fr6m the pin 86 and again connected with r .15 the crank-pin 79. When the shank 55 is.adjusted in the slot 56, it is desirabl@ to also adjust the power connection so that the @relation: o@ the abrading end 35ito:the grindin-g wheel @is main60 t,,tined. This is shown accom-Dlisl-ied by adI usting th6 length of the link 80, as by adjusting the fork 82 lengthwise 6f the Iii@k. ltlius the fork is provided : -,@vith I a, sliqiak 88. @ A e'am @b t 89 extends thr6ugh @a Iot 90 iii 65 the lip kc,"and is threaded..in the:shank-1. A pin 95:on the shaiik is sliclable in a; slot 96 'm the link f6r maintaining the link. and sh@,jak,parall@l. Manual ineans are @hown in Fig. 3 for oscillatin@ the: abrading. bar. These@ are io showii consisting of a shank 91 extendin(y froin the holder being secured to tl-ie,ilolder by a threaded conneletion @92 with the clampplat;e 28, the shank having a handle 9.3 exltended therefrom, by means@ of which th @e 75 liolder for the abrading bar may be oscillated for back and forth traverse the abradirig face of'the abrading bar crosswise@of the abrading stirface of the abradinz wheel. If it is desired to pl.ace th6 a5radin bar so 9 oti@L, of -L,,se,:the hoicler 25 is S,wung on its pivot and the handle 93 is connected @'with I a la-t-ch 94 extending from:th6 bracket. , Thi-,latch -@is a resilie-n@l@' vielding latch, and the handle is'yieldingly held therein. 85 Th@ abrading bar may comprise a serlos. of @nested individual abrading bars which extend parallel with each other in n . ested relatioii, and preferably spaced apa,rt, .so as to provide a greater number of abradina edgesfortheabrading),bar. Th6seindividu@l' abrading@ bars may be of various forms ancl tiested in various relations, and we have ii) Figs. 6. to 10 @ inclusive shown. various cro sssectional forms and ar-ra ngements of such iiesto,d. indiyidua,l ab@@clin- bars. ' ReferrfnLy to Figs. .6 anci 7, the @bradin@ bar is @hoT@@ cor@@'osecl of a nest of series of individual iibradino, bars 101, wbich are shown squar i 6r ss- e6tion, the inclivicl-Lial ioo e n o s g separate @-brading bars bein d by se@4rating @trips 102, 103, for spacing saia individual abrading bars @paxt in order -to present aii increased nuinber @ of 'abradiiik edges to the grinding surface of the -arindinly@ wheel. 105 . This series of @ indivi(i@i.%l abr@diiig bqrs; -v@hiel-i compose '@,he abradin4 bar proper,all act oil i@e:abradin(r slirface, and have an end abrading face, @vhicli is collec@uivel@ on the individlial abradiio- bars, ifi the form of an 'Ilo are described fron-i 'Lhe pivot@l. axis of -the hol-der. All these incliiiaual abrading bars act ;-ndi.vidi'- ' and collecti@el3T on the 'y sl, -%vheel. griiid'mg 'r@lace of , the , urinding The individual abradin..g bars are shifted ii5 I.ei@gthvvise j'n tile - hold@i- io tal@e -LIP wear. with their abradid.g elid'i@igi,.itain@ci in I a cU@ ate relation.. The series or nest of i-ndividual abrading bars ai-e @l-,ini@ed in the holcler in the, same 120 manner in wl@ich fl-ie in@eg@al ibrad,@ng,bar !9 i@ cl,,tmped. Fi 9 represents a se-ries of individual I@r, bar 105 wbich are rectangular iii pg S crOss7,9ectiol-I 1 and P,;m- ar@ange(I side by side, '@25 having., sp,,iclrig strii)@ @106 'beiwe@@n t-l-lem. Thlis. series oi individual abrading bai@s is cJ.Pinpc-d:ii, the holder in manne.@ Simto the intearil ahm, ding bar 19. @ The tbradiiag end.of the nest of abradin@, ba-rs is