Document peYZn3OeomkYe0x8GDdokoXBX

Feb. 14, 1956 Filed Jan. 21, 1953 H. R- BILLETER GRINDING DEVICE 2,734,319 4 Sheets-Sheet 1 a L__ 1-- \$D. s -L.___ INVENTOR. HeriryJioberb-BiUete:^ BY Feb. 14, 1956 riled Jan, 21, 1953 H. R. BILLETER GRINDING DEVICE 2,734,319 4 Sheets-Sheet 2 Feb. 14, 1956 Filed Jan. 21, 1953 h. R. billeter GRINDING DEVICE 2,734,319 4 Sheets-Sheet 3 Feb. 14, 1956 Filed Jan. 21, 1953 H. R. B1LLETER GRINDING DEVICE 2,734,319 4 Sheets-Sheet 4 \ United States Patent O ce 2,734,319 Patented Feb. 14, 1956 positions, in which the adjusting means is of novel con struction facilitating its setting to aero position. 2,734,319 Still another object is to provide a device of the fore going character having novel means for stably mounting GRINDING DEVICE 5 Henry Robert Billelcr, Highland Park, Ii!., assignor to Ammco Tools, Inc., North Chicago, HI., a corporation of Illinois the' brake shoe holder on the carriage in such a way as to effectively withstand tendency to displacement of the holder relative to the grinding element so as to preserve proper alignment of the brake shoe held in the holder rela tive to the grinding element. Application January 21, 1953, Serial No. 332,319 10 Another object is to provide in a brake shoe grinder, a 7 Claims. (Cl. 51--96) grinding element of novel construction including a cylin drical abrasive sleeve, and means for retaining the sleeve in accurate, predetermined dimensions. A further object is to provide a brake shoe grinder hav The present invention relates to a grinding device and 15 ing a grinding element including a flexible, cylindrical has to do particularly with improvements in a grinding abrasive sleeve, and means for supporting the flexible device of the character disclosed and claimed in my prior sleeve in the form of an inner sleeve yieldably expansible application, Serial No. 180,425, filed August 19, 1950. in directions for increasing its diameter but capable of The grinding device to which the present invention being rigidly held against deflection from substantially relates is particularly adapted for grinding arcuate con- 20 cylindrical shape. tours and especially well adapted for dressing down the Another object is to provide a brake shoe grinder having exposed arcuate surfaces of automotive brake shoe linings a rotatable grinding element and a housing at least par to produce a true cylindrical face of proper radius to fit tially surrounding the grinding element, and means for the brake drum with which the brake shoe is to be used. collecting dust from the housing generated by a grinding In processing lined automotive brake shoes it is usually 25 operation, in which novel means is provided for sealing necessary to dress down a new lining so that the radius the portion of the housing in which the grinding element of curvature is the same as that of the brake drum with rotates against the emission of dust therefrom. which the brake shoe is to be used in order that the entire Other objects and advantages of the invention will be braking surface of the shoe will engage the brake drum apparent from the following detail description taken in when the brakes are applied. When a brake drum be conjunction with the accompanying drawings in which-- comes worn, it is usually bored out to insure that its Fig. 1 is a side elevational view of a brake shoe grind braking surface is truly cylindrical and as a result its ing apparatus constructed in accordance with the princi radius is greater than the radius of the brake shoe with ples of the present invention, certain of the parts being which it is associated. When an oversize brake lining is _ shown as broken away and others sectioned to more applied to such brake shoe it is usually necessary to dress 3o clearly reveal the nature of the invention; down the surface of the brake lining until its exposed Fig. 2 is a top plan view of the apparatus; curved surface is truly cylindrical, if it was not theretofore Fig. 3 is a front elevational view thereof; cylindrical, and of a proper radius to accurately fit the Fig. 4 is an enlarged, fragmentary cross-sectional view inside surface of the brake drum. taken approximately on the line 4--4 of Fig. 1; The present invention includes improvements in a Fig. 5 is an enlarged fragmentary view taken substan device for grinding brake shoes according to the above tially on line 5---5 of Fig. 1; considerations, having a rotatable grinding element, a car Fig. 6 is an enlarged fragmentary sectional view taken riage mounting a brake shoe holder for oscillation relative substantially on line 6--6 of Fig. 2; to the grinding element, means for adjustably moving the Fig. 7 is a cross-sectional view taken on line 7--7 of carriage toward and from the grinding element for cor- 45 Fig. 6; respondingly adjustably positioning the axis of oscillation Fig. 8 is a top plan view of the lower brake shoe clamp, of the brake shoe holder in spaced relation to the grinding with broken lines showing somewhat diagrammaticaUy the element, and means for adjustably moving the brake shoe relative positions taken by two brake shoes of different holder relative to the carriage in directions toward and sizes when in position in the clamp; and from the grinding element whereby the brake shoe holder 50 Fig. 9 is a Side elevational view of the lower brake shoe may be adjustably so moved relative to an axis of oscilla clamp and showing also a portion of the npper clamp and tion fixed relative to the grinding element. somewhat diagrammaticaUy a brake shoe in position in An object of the invention is to provide in a device the clamps. of the foregoing genera! character novel means for releas- The grinding device of the present invention is espe ably securing the carriage in adjusted positions. cially well adapted for grinding to true cylindrical con Another object is to provide a device of character noted tour the surfaces of linings attached to automotive brake having novel locking means for releasably securing the shoes and the device is described herein in connection carriage in any of a number of predetermined spaced posi with such use for the purpose of illustration. It will be tions and novel means for releasably retaining the locking understood that the invention is not thus limited and that means in disabled position. the principles may be applied to other uses where gener Still another object is to provide a device of the charac ally similar results are desired. ter referred to, having novel locking means for releasably Referring now to the drawings in detail and in par securing the carriage in any of a number of predetermined ticular to Fig. 1, the grinding device includes a base or spaced positions, means for releasably retaining the lock- _ frame 10 in the form of an elongated rectilinear casing ing means iD disabled position, and means serving to indi- 65 like member having a base flange 12 extending there- cate to the operator the positioning of the carriage in any around from which there extends upwardly and inwardly, of the predetermined positions, facilitating movement of preferably at a slight taper, a pair of side walls 14 and the locking means to locking position. 15, a front wall 18 and a curved rear wall 20. The top A further object is to provide a device of the above gen wall 22 of the structure constitutes a bed plate upon which eral character having means for effecting fine adjustments is mounted the principal operating elements of the appa of the carriage relative to any of its predetermined spaced ratus. The flange 12 is formed with a plurality of sup- 2,734,319 3 4. porting feet or pads 24 by means of which the base 10 may chamfered surfaces are cylindrical surfaces 63 terminat be secured to a supporting surface such as a work bench, ing in shoulders 64 defined by radial flanges 65 of rela with the flange 12 slightly elevated from the surface there tively small radial dimension. of to permit circulation of air beneath the apparatus for The sleeves 48 and 50 are mounted by placing them purposes that will become apparent presently. 5 in assembled, telescope condition over the upper end of Supported within an opening 25 (Fig. 1) formed in the the shaft into engagement with the lower washer 51, the top wall of the base 10 is an electric motor M which is inner sleeve 48 engaging a chamfered surface 62 on the suitably secured to (lie base as by means of a mounting bracket 27 and bolts 26. Current may be supplied to the lower washer. The upper washer 52 is then fitted over the sleeves and the screw 56 is threaded into the tapped motor by means of a cable 28 and a conventional switch 10 hole in the shaft which forces the upper washer down assembly 30 is provided to control the motor circuit. The motor M serves to drive a grinder 47 of novel construction wardly and the two washers relatively toward each other. The chamfered surfaces 62 on the two washers expand the adapted to dress down the surface of a brake shoe lining sleeves lo the dimension determined by the cylindrical por and hence is provided with a shaft 32 which projects down tions 63, whereupon expansion of the sleeves ceases and wardly in the base 10 and carries a driving pulley 34 15 continued threading of the screw 56 brings the shoulders thereon operatively connected by a driving belt 36 to a 64 into engagement with the ends of the sleeves. The driven pulley 38 mounted on a vertically extending shaft sleeves arc then rigidly mounted in assembly, the tend or spindle 40 which projects through an opening in the ency of the aluminum sleeve 48 to contract acting to es bed plate 22 of the base 10. The shaft 40 is mounted in tablish the desired frictional engagement between that upper and lower antifriction bearings 42 and 44, respec 20. sleeve and the washers for the rotation of the sleeve on tively, carried in a boss 46 formed in the bed plate. The the shaft. The engagement of the shoulders 64 with the shaft 40 projects upwardly above Ihe bed plate and de ahuninum sleeve limits the movement of the washers tu- tachably carries at its upper portion the grinding element ward each other and establishes a firm and solid assembly. 47 referred to above and shown in detail in Figs. 6 and 7. The recess 54 receives Ihe upper end of Ihe shaft and hence The grinding element includes an inner sleeve 48 of sub 25 the upper washer 52 is positioned concentric with the shaft stantially cylindrical form having an axially extending slot for true rotation of the sleeve with the shaft. Tile collar 49 throughout its length. The sleeve 48 is preferably of or projection 53 serves to engage the flange 57 in removing aluminum and, as such, is relatively rigid with respect to the screw 56 from the shaft whereby a positive force is resistance to deflection in localized areas, but due to the provided for removing the upper washer 52 from the shaft provision of slot 49, the sleeve has a limited degree of 30 and thereby from the sleeve assembly, The grinding ele yieldability in that it can be slightly expanded so as to ment 47 when assembled on the shaft as above described increase its diameter beyond its normal diameter. The forms a rigid cylindrical grinding wheel which serves to sleeve contracts and assumes a normal relatively small di accurately grind the brake shoe in conjunction with the ameter when it is dismounted from the shaft in which Ihe accurate positioning of the brake shoe relative to the grind slot 49 may be substantially closed or at least reduced 35 ing element. in dimension in circumferential direction. When the alu minum sleeve is placed on the shaft it is slightly expanded in diameter whereby the slot 49 is slightly widened and the sleeve in the expansion thereof comes into engage A hood 66 having an open front 67 is removably se cured to the base 10 as by means of wing fastening studs 68 (Fig. 2) and substantially encloses the grinding ele ment 47. The interior of the hood 66 communicates ment with the outer abrasive sleeve 50 for frictioaally 40 through a series of openings 69 with the interior of an supporting the abrasive sleeve and maintaining it in true annular suction chamber 70 surrounding the boss 46 be cylindrical form. The outer abrasive sleeve 50 is prefer neath the bed plate 22 and defined between the boss 46 ably made up of a relatively flexible material such as a and a depending circular flange 71 integral with the web with abrasive material on its outer surface. The bed plate. A second circular flange 72 formed on the bed abrasive sleeve may be formed as by wrapping a strip of 45 plate depends therefrom and surrounds the circular flange material on a suitable form and securing the adjacent 71 to define therewith an annular dust-collecting cham convolutions together as by adhesive material, and prefer ber 73. A ring-like cover plate 74 is removably secured ably the abrasive sleeve consists of several layers in super to the flange 72 and encompasses the driven pulley 38 posed relation. The completed abrasive sleeve thus has a and serves as a closure for the dust-collecting chamber normal cylindrical shape of nominal dimensions although it is relatively flexible and may be deformed. 50 73. hub Preferably the cover plate 74 closely approaches ihe of the pulley and above the cover plate is an im The inner sleeve 48 has a normal diameter slightly less peller 75 disposed in the chamber 70 and preferably con than the nominal diameter of the abrasive sleeve and the sists of a sheet metal stamping including a disc-like por means for mounting the aluminum sleeve produces an ex tion 76 and blade elements 77. The impeller may be se pansion of the aluminum sleeve so that it frictionally and 55 cured in place for rotation with the pulley and shaft by tightly engages the abrasive sleeve and maintains it in truly securement between Ihe pulley and bearing 44. The im cylindrical shape and of the desired ultimate dimension. peller 75 serves to draw air and the comminuted products The means for mounting the sleeve assembly made up of abrasion from the hood 6G into the suction chamber of the inner sleeve 48 and outer sleeve 50 includes a lower 70, and to expel the same by the action of centrifugal washer 51 and an upper washer 52, the lower washer be ing secured to the shaft 40 for rotation therewith by suit 60 force into the dust-collecting chamber 73. The chamber 73 communicates with an elbow device 79 (Fig. 2) which able means such as a pin 53 extending diametrically projects through the side of the wall of tire base and to through a hole in the hub of the washer and shaft. The which there 'is removably attached by means of a garter lower washer 51 is adapted to rest on the upper bearing spring a dust-impervious but porous dust-collecting bag 81. 42 and thereby serves as a means for supporting the shaft in axial position. The upper washer 52 has a recess 54 65 In order to seal'the suction chamber 70 and the dust collecting chamber 73 against the efflux of dust and com- adapted to snugly receive the upper end cf the shaft and a minuted'materials around the shaft 40, the pulley 33 is smaller diameter aperture 55 for receiving the shank of a provided wifh a seal 82 in the form of a ring of resilient screw 56, the aperture being surrounded by an inturned malerial fitted in an annular groove in the puliev and flange 57. The screw shank is threaded for threading into a tapped hole in the shaft, and is provided with a projec 70 engaging the under surface of the cover plate 74. The resilient sealing ring 32 is of greater diameter than the tion 58 fitted in an enlarged portion 59 of the recess in the central opening in the cover plate 74 and, being in yield shaft, and a knurled head portion 60. ing engagement with- the cover plate, seals the chamber The washers 51 and 52 include central portions 61 hav 70 against the passage of dust around the shaft. ing chamfered edge surfaces 62, and outwardly from the 75 Referring now to Figures 4 and 6, a carriage 83 is siid- 2,734,310 ably disposed on the upper surface of the bed plate 22 response to pressure applied to the pin for that purpose. for adjustable movement toward and away from the grind When the locking pin is in such retracted position its er 47. The carriage 83 is formed with an arcuate upper inner end is clear of the holes 95 enabling sliding move surface S4 (Fig. 4) of relatively long radius of curvature, ment of the guide bar or indexing bar 94 for selectively which surface is formed with a flat circular turntable bed 5 positioning the holes 95 for reception of the pin. or supporting surface SS (Figs. 1 and 6) on which there The rib 92 is also provided with a recess 109 (Figs. 4 is rotatably disposed a circular turntable 86 forming part and 5) opening upwardly through the upper surface bed of a pivoted carriage 7 adapted to support a brake shoe plate. Removably disposed in the recess 109 is a leaf holder 88. The carriage 87 pivots about a pivot axis spring 110 engaging at its ends with pins 111 fixed in established by a pivot pin 170 as explained more in de 10 the floor of the recess and engaging at its central portion tail hereinafter. with a ball 15.2 located in an aperture 113 which opens The carriage 83 is provided with downwardly extend through front the recess 109 to the groove 93, and which ing slide rails S9 (Fig. 4) which rest upon slide rails is in alignment with the locking pin 98. The aperture 90 which project upwardly from and extend longitudinal is of appropriate size to enable free movement of the ly of the bed plate 22. A continuous marginal flange 91 15 ball and the ball is of such a diameter that it enters overlies the edge of the top wall 22 and serves to pro into the tapered portions 97 of the hoLes 95 only to a tect the rails 89 and 90 against tire accumulation of the slight extent (Figs. 4 and 5). The leaf spring biases products of abrasion. the ball toward the indexing bar 94 and when any one The bed plate 22 is formed with an integral longitudinal of the holes 93 is in register with the ball the latter is ly extending depending rib 92 having a longitudinal groove 20 biased so as to enter the hole to a slight amount, whereby 92a formed in its upper surface, and the carriage S3 is in the movement, of the carriage as hereinafter explained, formed with a longitudinally extending, depending rib the operator experinces a "Feel" (hat one of (be holes 93 having a longitudinal groove 93n in its lorver surface 95 is engaged by tire ball and hence is in register with and in register with the groove 92u. An indexing bar 94 the locking pin 98 for receiving the latter. Preferably which is rectangular in cross section is slidably disposed 25 the leaf spring 110 can be removed merely by gripping in and enclosed within the grooves 92a and 93a and serves and lifting it out and it is restrained against longitudinal in the manner of a key or guide rail to align the carriage movement by the end walls of the recess, and normally 83 on the bed plate 22 in proper cooperating relation against upward removal by the adjacent element of the ship with respect thereto, while at the same time per carriage 83. mitting longitudinal adjusting movement of the carriage 30 The retention of the locking pin in retracted position 83 on the bed plate 22 in a direction toward and away from the grinder. The indexing bai 94 constitutes the eliminates chattering of the locking pin in engaging the holes, as when the operator would retract the pin and sole means for guiding the carriage 83 against the lateral release it when the carriage and indexing bar is moved, displacement on the bed plate 22. It also serves as an and consequent wearing of the edge surfaces of the holes. element of the indexing means hereinafter described for 35 The ball 112 is normally effective to retain the indexing selectively positioning the carriage S3 in any one of a bar in the selected posilion by engagement with the plurality of spaced, predetermined positions on the base 19. corresponding hole, but if for any reason the selected The indexing bar 94 has formed therein a series of hole is not accurately aligned with tile locking pin, the longitudinally spaced aligned openings or index holes tapered surface cn the pin will engage the bell-mouth 95, each of which is bell-mouthed at one end as at 96 HO surface on the hole and produce a camming effect on (Fig, 5), and provided with a relatively short bevel or the indexing bar and move it to accurate position. The taper 97 at the other end. The holes 95 are adapted upon movement of the indexing bar 94 to be selectively brought into register with the inner end of an iudexing or locking nip. 98 which is slidably disposed in a bore 99 Formed in ball enters the hole to such a slight extent that only relatively flat camming surfaces are established there between. Any wearing or mutilation that may occur on the edge surfaces of the holes will not affect the desired the rib 92 and opening into the groove 92a and in a bore 110 line contact engagement between the pin and hole, and 100 formed in a side wall 14 of the base IS. A coil spring accurate alignment of the indexing bar is thus obtained. 101 surrounding the pin 98 bears at one end against a In order that the operator may determine which index washer 102 carried by the pin and at the other end against hole 95 is in register with tile end of the locking pin an internal boss 183 to yieldingly urge the pin inwardly of the base so that the inner end thereof may enter and 50 98, a reference mart 113 (Fig. 1) is provided on the carriage S3 and cooperates with the index scale 114 which is yieldingly held in a selected opening 25 of the guide for convenience may be provided on the machine name bar. A handle or knob 184 is provided on the outer end of (he locking pin 98 to facilitate manipulation of the plate 115 which may be attached to the side wall 14. The carriage 83 is operatively connected to the indexing latter, and the inner end of the pin is tapered at IS5. bar 94 so that it is maintained in adjusted position on The taper 105 of the pin and the bell-mouth shape 96 the base 10 as determined by the position of the indexing of the holes are so relatively shaped and proportioned that substantially line contact therebetween is established, bar S4. To this end the indexing bar 94 (Fig. 6) is normally urged toward the forward end of the carriage at a position disposed well inwardly of the ends of the 83 by a compression spring 116 centered on a pin 117 holes, so that accurate alignment of the indexing bar will be effected as will be referred to later. Adjacent its outer GO projecting inwardly from the rear end of the carriage 83 and bearing against the rear end of the indexing bar end, the locking pin 98 is provided with an annular groove 106 adapted to receive a detent plunger 107 slidably dis 94. A micrometer adjusting screw 118 of novel con struction is provided at the front end of the carriage posed in the boss 103, radially of the locking pin, for in position to be abutted by forward end of the indexing yieldingly retaining the locking pin in retracted position (to the left, Fig. 4). The detent plunger 107 is biased 05 bar and serves to determine the forward position of the indexing bar relatively lo the carriage. upwardly or toward the locking pin by means of a leaf The indexing holes 95 are so located on the indexing spring 108 solidly anchored at its inner end by suitable bar 94 as to establish spaced predetermined positions means and with its outer end normally biased upwardly of the carriage S3 on the base 10 and accordingly to and engaging the detent plunger. When the locking is 70 establish corresponding predetermined positions of the retracted and the groove 106 is in register with the de pivot axis of the carriage 87 relative to the surface of the tent 107, the latter is biased upwardly into the groove and grinding element 47. In the present illustrative embodi releasably retains the locking pin in retracted position. ment the indexing holes 95 are spaced apart on one-half The groove and detent have interengaging surfaces act inch centers and are so located as to determine positions ing as camming surfaces effective to retract the detent in 75 of the aforesaid pivot axis spaced from the grinding elc- 3,734,319 78 ment 47, ranging from 494 inches lo B inches. The setting of the knob 124 fixes the axial position of the several indexing holes 95 are labeled respectively with adjusting screw and securement of the sleeve on the knob indicia representing diameters corresponding to the re fixes the sleeve and thereby the assembled adjusting spective radii which the holes establish as above ex screw in circumferential or rotational direction with re plained. For example, the hole 95 at the right hand end 5 spect to the zero position. The construction of the ad of the scries (as viewed in Fig. 6) is so located that justing screw 118 eliminates the necessity for justifying when the carriage is in the position in which that hole the threads on the screw and provides a simple and effec is in registry with the locking pin SS and the screw 118 tive means for making the proper initial accurate setting. is in its zero position, the pivot axis of the carriage is Means are provided for securely locking the carriage exactly 4`A inches from the surface of the grinding ele 30 83 to the bed plate 22 in any one of its indexed or ad ment. justed positions. To this end a locking assembly is pro The adjusting screw 118 is made up of relatively ad vided which includes clamp shoe 131 (Figs. 4 and 6) justable elements enabling its setting to an accurate zero tiltably supported on a collar 132 which is supported on indicating position, thereby eliminating the necessity for an adjusting nut 133 threadedly received on the lower extreme accuracy in this respect in the manufacture 13 end of a stud 134, the other end of u'hich is threadedly thereof. The adjusting screw 118 includes a shank 119 received in the carriage S3. A thrust pin 136 has its threaded on its outer end portion and preferably pro lower end seated in a depression I3S provided in the vided with a screw driver slot. The inner end is threaded damp shoe 131 and has a portion 140 thereof threadedly into a bushing 120 suitably secured stationarily in a bore received in the carriage 83. A handle 1-12 is fixedly 121 of tile carriage in longitudinal alignment with the 20 received in the head 144 of the thrust pin 136 and is indexing bar 94. The innermost end portion of the adapted to be swung from the full line position thereof shank is preferably of reduced diameter at 122 and fitted with a sleeve bushing 123 slidable and rotatable rela indicated in Fig. 2, wherein it is in engagement with a limit stop or abutment 146, lo a dotted line position tively to the outer bushing 120. The inner end of the wherein it is in engagement with an abutment 148. In shank engages the indexing bar and serves to provide 2a Inc full line position of the handle 142, the clamp shoe relative movement between the carriage and indexing bar upon appropriate turning of the adjusting screw. The adjusting screw 118 includes a knob 124 having a 131 has its clamping surface 150 in light engagement with the underneath surface of the bed plate 22 while in the dotted line position of ihe handle 142 the clamping radial flange portion and a sleeve portion threaded on surface 150 bears firmly against the underneath surface of the shank and provided with a set screw 125 for en 30 the top wall 22 of the base 16 and serves to lock the car gagement with the shank for adjustably setting the knob riage S3 in its desired position of adjustment. Tile rib relative to the shank. The adjusting screw also includes 92 is provided with a longitudinally extending slot through a sleeve 126 telescoped with the sleeve portion of the which the stud 334 anti pin 136 extend, enabling sliding knob and also provided with a set screw for engagement movement of the carriage. with the knob for releasably securing the two elements 36 A headed pivot pin 170 (Fig. 6j in the form of a together in adjusted relation. The bushing 120 is pro shoulder bolt extends through and is secured to ihe car vided with indicia markings (Fig. 2) including an axial riage S3 centrally of the bed surface 85 thereof as by a line 12S and axially spaced lines 129. The sleeve 126 nut 171 and passes through bosses 172 and 174, provided is provided with circumferentially spaced markings 130 on the carriage 83 and on the turntable 86 respectively, cooperating with the markings 128 and 129 on the bush 40 and serves to center the turntable 36 on the bed 85 while ing. permitting turning movement of the carriage 87 as a For the purpose of making the initial adjustment of the tvhole about the axis of tile bolt 170, which is the pivot adjusting screw 118 so that it accurately indicates the axis above mentioned, in the manufacture of the device, adjustment made thereby, the indexing bar 94 is moved the head of the belt 170 is held to close tolerances and to any arbitrary position, for example, to a 9-incli posi 4a accurate concentricity relative to the shank, so as to pro tion in which the locking pin 98 enters in the 9-inch hole, vide an accurate reference point for the initial setting of i. e., the hole at the far right (Fig. 6). At such posi the device. tion of the indexing bar and at the zero position of the The carriage 87 includes an upstanding portion 176 adjusting screw 118 the axis of the pin 170 is to be exact having a pair of transversely spaced bearings 178 formed ly four and one-half inches from the surface of the abrasive sleeve 51, a measurement in practice obtained by 50 therein each of which may consist of longitudinally spaced portions formed in opposite wail members of the gauging the distance between the axis of the pin 178 portion 176. Tile bearings 178 respectively receive there and the axis of file grinding element. If, however, the in elongated reds or supporting bars IKS for longitu distance between the axes mentioned is not as indicated dinal sliding movement of the rods or supporting bars in the operator threads the adjusting screw 318 to the posi tion in which that distance is as desired. Turning of the 55 the bearings and consequent movement of the brake shoe holder 88 to be later described, toward and from the adjusting screw moves the carriage relative to the in grinding element relative to any given fixed position of dexing bar 94 which is located relative to the base and the carriage 83, thereby the carriage is moved relative to the grinding The brake shoe holder or chuck 83 (see Figs. 6, 8 and element. Thereafter the operator applies a screwdriver to the slot in the shank 119 and after loosening the set 60 9) includes a lower ciamp or supporting bracket 192 hav ing transversely spaced portions 193 (Figs. 2 and 8) each screw 125 rotates the knob 124 until the edge of the of which lias a tubular element 194 receiving the rear sleeve 126 registers with the appropriate indicia marking end of one of the supporting bars 138 and secured there 129 and then tightens the set screw 125. If the zero to by means of a set screw 195, so as to be movable marking of the index 139 is not then in register with the line 125 for indicating the zero position, the operator 05 unitarily with the supporting bars. The supporting bracket 192, which may be formed as loosens the set screw i.27 and rotates the sleeve 126 rela a casting, includes a lower, generally T-shaped portion tive to the knob until such zero position is indicated. The 196 (Fig. 8) which lias formed thereon at spaced points set screw 127 is then tightened. The knob 124 and a pair of bosses 198, each having an upstanding rib or sleeve 12G thereafter form an effectively integral part. The inner edge of tile sleeve 126 thus serves as an index 70 pad 235 designed for reception thereon of the arcuate center flange F of a brake shoe BS, the lining L of which ing line or indicia mark. Tt is to be understood, of is lo be ground. A locating pin 199 extends through course, that rotation of the sleeve 126 relative to the knob each boss 198 and is adapted to be adjustably secured does not produce any axial movement of the sleeve rela in position therein as by means of a set screw 201. The tive to the knob, and upon setting of the shank 119, 75 locating pins 199 preferably liavc tapered ends 201 2,734,310 9 adapted to engage the inner surface of the brake shoe any brake shoe within the aforesaid range of sizes at rim R at spaced points thercalong when the brake shoe points which are approximately equidistant from the rim. is placed in the holder to properly position the brake Referring now to Fig. 8 wherein there is shown some shoe therein. what diagrammatically the relative positions of two brake The supporting bracket 192 is provided with an over- 5 shoes in position in the holder, namely, the smallest stand lying portion 200 including a threaded boss 202 which ard brake shoe BS' and the largest standard brake shoe receives therein the threaded end of a clamping stud 204. BS", respectively. It will be noted that the two outer An upper clamp or clamping head 206 slidable on clamp pads 205 are positioned to engage the flanges F' and F" ing stud 204 is provided with an apron 210 which encloses of the respective brake shoes ES' aud BS" at points along the boss 202 and certain other elements hereinafter de- 10 lines C' and C" representing arcs drawn about the centers scribed, and a pair of spaced toes 212 formed at spaced points at its rear end and disposed above and in align of curvature of the rims R' and R" of the brake shoes BS' and BS", respectively, and passing along the flanges ment with the pads 20S for clamping engagement wilh the upper surface of the flange F of the brake shoe to be F' and F" intermediate the rims R' and R" and the inner edges of the flanges F' and F". The center pad 203 is processed. The clamping stud 284 passes through a boss IS positioned to engage the flanges at a point on each flange 214 formed on the head 206 and is provided with a manip respectively between the arcs C' and C". Accordingly, ulating knob 216 by means of which the head 206 may while the center pad 203 does not engage either flange at be moved downwardly to bring the toes 212 into clamping precisely on the arc drawn about the center of curvature engagement with the flange F of tire brake shoe. A spring it does engage each flange at a point sufSciently close to 218 disposed between the apron 210 and overlying por- 20 such arc that the error thus resulting does not seriously tion 200 of the supporting bracket 192 serves to yield affect the proper positioning of the brake shoe in the ingly urge the movable head 206 toward open position holder. relatively to the supporting bracket 192. The portion 196 is also provided with a third upstand While the holder has been described with particular reference to its use in connection with brake shoes having ing rib or pad 203 located intermediate the two outer 25 tapered flanges, it will be apparent that it is aiso suitable pads 295, the upper surface of the pad 203 and the upper surfaces of the pads 205 lying in a common plane per for use with brake shoes having flanges of uniform thick ness. pendicular to the abrasive surface. The pad 203 and the Means are provided for adjustably positioning the sup two pads 295 are disposed generally along the arc of a porting bars 1SS and the holder 88 relatively to the pivoted circle and are so located that when any brake ritoe within 30 carriage 87 and for rocking the latter about its pivot. the range of sizes which the holder is designed to accom Such means includes a tubular socket member or block modate is disposed in position in the holder, the flange 222 of externally square cross-section, tiltably mounted of such brake shoe is engaged by the three pads 293 and upon a rock shaft 208 and provided with a cylindrical 205 at points approximately equidistant from the rim, bore 224 therein adapted to receive one end of an elon which points He in trie aforementioned plane which is per- 35 gated operating rod 226. The rock shaft 203 extends pcndicu'ar to the abrasive surface. Accordingly, and as will appear hereinafter, any brake.shoe within the afore said range of sizes will be supported in position with its between and is supported in a pair of forwardly extend ing side flanges 220 (Figs. 6, 8 and 9) formed on the supporting bracket 192. The rear end of the rod 226 is braking surface extending substantially vertically and provided with an annular groove 223 therearound and therefore substantially parallel to the abrasive surface of ^ the rock shaft 298 passes through the socket member 222 the grinder. in such a manner that it enters the groove 228 and serves In the case of many conventional brake shoes the flange as a locking pin for holding the end of the operating rod extends with its medial plane perpendicular to the exposed 226 within the bore 224 of the socket member 222 against braking surface of the brake shoe lining, but since the longitudinal or axial shifting movement while at the same flange increases in thickness in a direction from the rim A` time permitting free taming movement of the rod 226 toward the inner edge of the flange, the faces of the flange relative to the socket member 222. therefore are not planar and are not parallel to the medial From the above description of parts it will be seen that plane of the flange but are portions of cones and diverge the rock shaft 203 serves the functions of tiltably sup from the rim and are inclined to the medial plane. Ac porting the socket member 222. and of holding the end of cordingly, if the brake shoe were supported in the grinder the operating rod 226 within the bore 224 of the socket of (Iris invention with one face of the flange clamped member 222. against a flat, horizontal surface, or two spaced surfaces, The operating red 226 extends forwardly of the brake extending over a substantial portion of the radial length shoe supporting assembly to overlie the forward end of of the flange, or three surfaces not equidistant from the ^ the machine and is provided with threads 230 through rim, the brake shoe would be positioned with its medial Ji ; out the major portion of its length. A handle 232 (Fig. plane inclined to the abrasive surface aud consequently 1) is secured on the forward end of the rod 226 in order the exposed braking surface would also be inclined to the that an operator may impart turning movements to the abrasive surface. However, in the holder of the present rod as well as to oscillate tile same from side to side. invention the flange of the brake shoe is clamped against The threaded portion 23G of the rod 22-5 is adapted to be three spaced supporting surfaces of relatively narrow ex- " ) received in a "half-nut" structure 234 provided on the tent (measured in a direction radially of the brake shoe) carriage 87 by virtue of a pair of upstanding members and the surfaces are so arranged that they engage the or ears 236 (Figs. 2 and 3) which define therebetween brake shoe at three spaced points approximately equidis a semicircular threaded bore 233, the threads of which tant from the rim. Since, as aforesaid, the three support are designed for cooperation with the threads 230 on ing surfaces lie in a plane normal to the abrasive surface the brake shoe is therefore supported with its exposed 6 the rod 226. The flat sides of the socket 222 cooperate with the side flanges 220 to constitute means for main taining the threaded portion 239 of the rod 226 in vertical braking surface, extending substantially parallel to the alignment with the half-nut 234 so that upon downward abrasive surface, i. e,, in a position that may be, for prac swinging movement of the rod 226 in any position of the tical purposes, considered parallel, because the variation j turntable the threaded portion 230 will fai! into register from parallel arrangement in any particular case would automatically with the half-nut 234. be negligible. In order to permit the holder to accommo Since the rod 226, by virtue of its reception in the date brake shoes of various radii, as for example brake socket member 222 is pivoted for rocking movement shoes for brake drums having diameters' ranging from 9 about the axis of the rock shaft 298 in a vertical plane, lo 16 inches, the pads are disposed so that they engage 1 it will be seen that the operator may at will lift the rod 2,784,316 11 12 226 out of the half-nut structure 234 to disengage die position (as shown in Fig. 2), so that the thrust pin 136 same therefrom and by applying a thrust or a pull to engages the depression 138 provided in the clamp shoe the tod 226, as the case may be, slide the holder 88 and 331 to tilt the shoe in a clockwise direction (as viewed the supporting bars 188 as a unit longitudinally of the in Fig. 6), and thus bind the carriage S3 and base 10 machine toward and away from the grinder 47. Such 5 against relative displacement. sliding movement of the holder 88 by the application of Prior to the grinding operation it is, of course, neces a thrust or a pull to the rod 226 provides a fast or coarse sary to properly position a brake shoe of the desired size adjustment for the purpose of advancing a brake shoe into initial grinding relation with respect to the grinding wheel in the holder 88 and accordingly the knob 216 is manip ulated to back off tbe clumping stud 204 to move clamp 47. When the lining L of the brake shoe has been 18 ing jaws 212 away from the bosses i98 after which time brought into close proximity to the surface of the grind a brake shoe BS is positioned in the holder with the flange ing wheel 47, a fine adjustment may be made by lower F resting on the surfaces of the pads 283 and 285 and ing the operating rod '226 into the half-nut 234 for en with the locating pins 199 engaging the inner surface of gagement between the threads thereof with the threads the rim R at spaced points. Tightening of the knob 216 230 on the rod, after which turning movement of the 15 will serve to move the clamping head 206 downwardly handle 232 in one direction or the ether will feed the and cause the jaws 212 to engage the flange F and clamp bolder 88, together with the brake shoe supported thereon, the same against surfaces of the pads 203 and 205 in toward the cylindrical grinding wheel 47 for grinding proper position for grinding the lining L of the brake purposes. A scale '227, graduated in thousandths shoe. The brake shoe is positioned in the holder by of an inch, is provided on the rod or feed screw 226 20 abutment with the two pins 199 which are so located and cooperates with a reference mark 22? on the socket that the surface, of the brake shoe is concenlric with the member 222 to indicate the extent of the feed just described. pivot axis of the carriage 87 and the surface of the lining L is closely parallel to the abrasive surface of the grind It has been found that the operator when swinging the ing wheel 47. Accordingly when the carriage 37 is rocked rod 226 to rock the carriage 87 about its pivot (as herein 25 about its pivot axis, with a brake shoe positioned in the after explained) often tends to turn the rod 226 unin holder 88, the brake shoe surface moves about such axis tentionally about its axis and thereby advance or retract in a true circular path. the brake shoe holder. Accordingly, I preferably pro With the brake shoe BS thus positioned in proper align vide suitable friction means for inhibiting such turning ment with the grinding wheel 47, the holder 88 may, by movement of the rod 226 relatively to the half-nut 234. 30 a fast adjustment :as previously described, be brought to To this end I preferably form a bore 235 in the end por a position wherein the lining L is brought into dose prox tion of the rod 226 and dispose therein two bearing balls imity with the abrading surface of the grinding wheel 237 which are yieldingly urged into engagement with the 47. To accomplish this the operating rod 226 is man wall of the bore 224 by a coil spring 239 with sufficient ually tilted upwardly about its pivotal axis of support force to provide the desired resistance to turning move 35 on the shaft 208 so that tire threaded portion 230 of the ment of the rod in the socket 222. operating rod is removed from the half-nut structure after The provision of the transversely spaced rods or sup which, by exerting.a manual thrust on the rod 226 holder porting bars IBS provides great stability of the brake 8S is advanced until the surface of the lining L closely shoe holder 88 so that it will not rock or tilt about a approaches the grinding surface of the grinding wheel longitudinal axis. This accurate positioning of the brake 40 47. At this time tbe threaded portion 230 of the oper shoe holder together with the accurate shape and dimen ating rod is lowered into the half-nut structure 234 to sions of the grinding element assure that the brake secure the holder 88 in position. With the brake shoe shoe lining will be ground and finished to a surface of lining L in close proximity to the cylindrical grinding truly cylindrical form. Furthermore, there is no rocking surface of the grinding wheel 47 and with the threaded movement of the brake shoe holder about a transverse axis. 45 portion 230 of the rod 226 located within the half-nut structure 234, the operator may, by rotating the rod 226 To illustrate the operation of the apparatus in process in a clockwise direction (as viewed in Fig. 3), accu ing the lining L of a standard brake shoe BS in new rately feed the lining L toward the rotating grinding wheel. condition, it may be assumed that a 9 inch brake shoe For any setting (i. e. position of adjustment) of the is to be processed for use with a brake drum which is exactly 9 inches in diameter. Thus for effective process 50 carriage 83 on the base 10, the distance from the center of the pivot pin 170 to the nearest portion of the surface ing of the lining L, grinding operations on a 4V6 inch of the grinding element 47 remains constant. Hence, all radius will have to be performed so that the surface of points on the surface of a brake shoe which are at a the brake shoe lining will have an arcuate contour formed distance from the center of the pivot pin equal to the with a 4V6 inch radius. It is necessary, therefore, that during (he grinding operation the distance from the pivot 55 distance between the center of the pin and the surface of Ihe-grinding element will, when the holder 88 is rocked axis of the carriage 87 (Fig. 6) to the periphery of the about the, pivot pin, move in an arc having a radius of grinding surface of the grinding wheel 47 be 4!A inches. curvature equal to the distance between the center of With the handle 142 in its full line position (as shown the pivot pin and the surface of the grinding element. in Fig. 2), the clamp shoe 131 is free and (he carriage 83 is capable of free sliding movement on the bed plate or 00 When the rod 226 is swung from side to side and rotated to impart feed movement to the holder 88, the surface top wall 22 of the base 10. Inasmuch as the brake shoe of the lining-will be dressed down by the grinding wheel is to be ground to a 4Vi inch radius no adjustments of to a true circular arc having a radius of curvature cor the adjusting screw 118 (Fig. 6) are necessary other responding to the setting of the indexing means. Screw than to ascertain the fact that the scale 130 is at its zero position. 05 feed movement of the rod 226 in a direction toward and away from the grinding element regulates the amount of The end of the indexing locking pin 93 is retracted and material removed. the carriage S3 is moved to an approximate position In certain instances the operator may wish to dress the wherein the opening or hole 95 labeled "9" is brought lining.down a predetermined amount or to determine ex into register with the locking pin 98 (Fig. 5), after which 70 actly to what extent the lining has been dressed down. release of the pin 98 will permit (he spring 101 to urge The distance that the holder is moved by the fine screw tile pin inwardly into the opening 95 to index the carriage feed, and thus the extent the lining has been dressed down, S3 to its proper position for grinding on a 416 inch radius. may be determined by observing the scale 227 on the To lock the carriage 83 securely in this position the handle rod 226 .with reference to the index mark 229 on (he 142 is moved from its full line position to its dotted line 76 socket member 222. 2,734,310 13 .... 14 In processing brakes it is often found that the drum out of locking engagement with said indexing bar in any had been badly scored and that in order to provide a true of a number of positions of the indexing bar, said lock cylindrical braking surface the drum has to be bored ing means having a recess therein detent means, and means out to make its surface truly cylindrical, The brake shoe resiliently urging said detent means into engagement with must be relined and dressed accordingly. If, for exam- 6 said locking means, said detent means registering with pie, a depth of 0.060 inch of metal is removed from a 10 said recess in said locking means in the non-locking posi inch diameter drum thereby increasing the drum diame tion of the latter and operative for releasably retaining ter by twice that amount, it is apparent that the dressing said locking means out of locking position. procedure on an oversize new lining provided on the 2. A grinder comprising a base, a grinding element sup original brake shoe would have to be conducted with 10 ported on said base, a carriage means supported on said the grinding taking place on a radius of 0.060 inch greater base, a holder for an article to be ground supported on than the fine radius of the original standard drum and said carriage means, said carriage means being slidable on brake shoe. In such case it is necessary to adjust the the base toward and from said grinding element and hav sliding carriage 83 so that the pivot axis of the pivoted ing a plurality of locking elements spaced longitudinally carriage 87 assumes a position 5.060 inches from the 15 along tbe line of its movement, locking means mounted in surface of the grinding wheel 47, whereby, upon oscil said base for movement into and out of locking engage lation of the carriage 87 during the grinding operation, ment selectively with said locking elements according to the radius of the path of movement of the dressed surface the adjusted position of said carriage means, spring means of the lining will be 5,060 inches. biasing said locking means toward the position of lock To provide for the grinding of a brake shoe lining L 20 ing engagement, said locking means having a recess there on such an oversize radius of curvaUire as that given in detent means, and means resiliently urging said detent in the example outlined above, it is merely necessary means into engagement with said locking means, said de for the operator to index the carriage S3 by moving it tent means registering with said recess in said locking to the appropriate position wherein the second hole of means in the non-locking position of the latter and opera the series (reading from right to left in Fig. 6) is in regis- 25 tive for retaining said locking means out of locking posi try with the pin 98 and permitting the pin to enter the tion against the action of said spring means, said recess in hole, and to move the adjusting screw 118 to a position said locking means and said detent means including coop wherein the 0.120 index is indicated. This latter adjust erating camming surfaces effective for moving said detent ment is attained by a clockwise movement oE the ad means to releasing position in response to pressure applied justing screw which feeds the adjusting screw inwardly 30 to said locking means in excess of that exerted by said of the carriage. The end of the adjusting screw thus spring means in the direction of locking engagement. bears against the end of the indexing bar 94 and draws 3. Locking means for a device having a base and a the carriage forwardly the desired 0.060 inch distance. member mounted on the base for sliding movement there The grinding of the lining L on the 5.060 inch radius on, comprising a plurality of locking elements on the may then take place in Lite maimer previously described 35 movable member at predetermined spaced locations along by oscillation of the rod 226 from side to side. the line of movement, a plunger mounted in said base Eor From the above description, it will be noted that the indexing bar effectively becomes a part of the carriage sliding movement in directions transverse to the line of movement of the movable member into and out of engage when the bar moves with the carriage in initially adjust ment selectively with said Locking elements for locking ing the carriage according to the positions determined by 40 the movable member in adjusted position, spring means the holes 95; and it effectively becomes a part of the base biasing said plunger toward locking position, said plunger when it is locked by the pin 98 and the carriage is ad having a recess in its periphery, detent means mounted in justed relative to the indexing bar by means of the said base for sliding movement into and out of position adjusting screw 118. engaging (he surface of said recess, and spring means bi The device of the present invention provides conven asing said detent means toward its said position, said de ient means for forming a bevel on each eDd of die brake 45 tent means and two opposite surfaces of said recess having shoe lining by a simple manipulation of the operating rod 226 and without changing the setting of the carriage 87. To form such bevel, the operating rod is raised out of engagement with the half-nut and the carriage 87 swung to a position wherein one end of the brake shoe lining is opposite Lite grinder 47. By appropriate manipu lation of the rod 226, the holder 88 is then moved rear wardly without swinging movement to push the end of the brake shoe lining against the surface of the grinder 47 and thereby grind a bevel on the end of the lining. The holder 83 is then backed off and swung to a posi 50 55 interengageablo camming surfaces operative for moving said detent means out of said recess in response to a force applied to said plunger in either direction in excess of the holding force exerted by the first spring means. 4. A grinder comprising a base, a carriage mounted on the base for sliding movement thereon, an indexing bar slidable on said base and engaging said carriage for posi tioning the latter on said base, said bar having a plurality of holes extending transversely therethrough at predeter mined spaced intervals along the line of movement of the tion to bring the other end of the lining opposite the grinder whereupon the beveling operation is repeated in carriage, said holes having outwardly diverging surfaces on one side of the bar, a pin slidably mounted in said base respect to that end of the lining. on one side of the indexing bar, having a tapered end en- From the foregoing it will be seen that the present 60 gageable selectively with the diverging surfaces of said invention provides a grinding device which is especially holes and operative for locking said carriage against move well adapted for grinding lined brake shoes to true arcu ate contour, which is simple in construction, and which may be made economically. At the same time, however, ment, a ball mounted in said base on the other side of the indexing bar in alignment with said pin for movement into and out of engagement selectively with the edges of said the device is rugged and sturdy and can be used for a long 65 holes and being dimensioned relatively to the holes so as period without likelihood of breakage of parts and with to extend thereinto a slight extent and present surfaces in out the necessity of replacing parts. engagement with the edges of the holes of such inclination I claim: as to enable the ball to be forced out of the holes in re 1. A grinder comprising a base, a grinding element sup spouse to movement of the carriage, and spring means bi ported on the base, a carriage mounted on said base for 71 asing said ball toward the index bar. sliding movement toward and from said grinding element, 5. A device of the character disclosed comprising a a holder for an article to be ground mounted on said car base, a carriage slidably mounted on said base, said car riage, an indexing bar slidable on said base and engaging riage having an element extending along its line of move said carriage, for positioning the latter on said base Lock ment provided with a plurality of holes spaced longitudi ing means mounted in said base for movement into and 7 nally therealong at predetermined intervals, said base hav- 3,734,319 15 16 ing a cavily and an aperture through a wall of the cavity inner ends for engaging the inner sleeve and expanding it adapted to align selectively with said holes according to into direct frictional engagement with the abrasive sleeve the position of the carriage, a ball in said aperture of throughout the length of the latter, cylindrical surfaces greater diameter than the holes, longitudinally spaced pins axially outwardly of said camming surfaces, and radial in the cavity positioned on opposite sides of said aperture, 5 shoulders axially outwardly of said cylindrical surfaces cri- and a leaf spring interposed between saidpins and bail and gageable with the ends of the sleeves, said spindle extend operative for biasing the ball toward the said carriage ele ing through one of said end members, and (he other end ment having said holes. member having a recess receiving an end portion of the 6. A grinding device comprising a base, a grinding ele spindle, and screw means extending through said other end ment mounted on said base, a carriage mounted oh said 10 member and threaded into said end of the spindle, said base for sliding movement toward and from said grinding screw means having a head engaging the outer surface of element, an indexing bar mounted in said.basefor sliding the end member and a shoulder engageable with the in movement relative to said base and to said carriage, means ner surface of the end member for positively removing the mounted in said base for releasably locking said indexing end member from the assembly in response to removal of bar in any of a number of predetermined positions, means 15 the screw means from the spindle. normally retaining said carriage in engagement with said indexing bar for movement therewith, and means for ad References Cited in the file of this patent justably moving said carriage relatively to said indexing UNITED STATES PATENTS bar, said last means comprising an element on said car riage having an axially extending zero indicia mark and axially spaced graduated- indicia marks, a screw threaded ly mounted in said carriage in engagement with said index ing bar, a knob threadedly mounted on said screw and having indicia means with a circumferentially extending indicia mark and circumferentially spaced indicia marks, said knob being adjustable axially of said screw, and said indicia means being adjustable rotationally of the knob in fixed position axially thereof, 7. A grinding element comprising a spindle adapted for rotational mounting, a cylindrical inner sleeve of rela tively rigid, resilient material having a longitudinal slot enabling limited expansion thereof in radial direction and thereby having a normal diameter and an expanded di ameter, a seamless abrasive sleeve surrounding said inner sleeve of a diameter within the limits of diametrical di mensions of the inner sleeve, and a pair of -end .members 282,509 343,478 580,665 599,245 937,480 1,101,171 1.282,030 1,706,644 1,883,747 2,083.793 2,102,915 2,225,806 2,345,161 2,429,752 2,580,865 2,637,145 Fearey . Aug. 7, 1883 McArthur_______ ______ .. June 8, 1886 Goshoin ---------------- Apr. 13, 1897 Merrill _ ____________ . Feb. 15, 1898 Smith et al.__________ - Oct. 19, 1909 Fischer . June 23, 1914 Benemelis ___________ Oct. 22, 2918 Woemle Mar. 26, 1929 Maddox - Oct. 18, 1932 Price__ _______ _ - June 15, 1937 Rishel_ Dec. 21, 1937 Stone__________________ . Dec. 24, 1940 Thomason____________ Mar. 28, 1944 Greulach_____ _ ... Oct. 28, 1947 Wallen . ............. Jan. 1, 1952 Wasley______________ .. May 5, 1953 FOREIGN PATENTS mounted on the spindle having, camming surfaces on their 378,974 Germany ___________ _ Aug. 9, 1923