US1837821A - Centerless grinding machine - Google Patents

Description

Een 229 MBL H. Wv HOLMES CENTERLESS GRINDING MACHINE Filed Oct. 2l 1925 .2 Sheets-Sheet l ILL @EEG

GRE

'ty has been errieneed heretofore in grinding thin cylinc l Work, such. es heli or rolllre shoes7 rings9 discs, end Veendency for such er Deering reces9 or the lilre. has .eeen e.

Work to lLWis during grinding es Well izo fell over owing it unstable condition when Q i il: lies heen dilicul. so l '1 1 'L reed the Work to grinding pcsdion Wien iis eins maintained in L of. '4f-lie erder such grinding Wheel l 'Y n ioriiy ane .sans oi -ns. cylindrical Werl; serbi" `he Work nous?J niei` i ained, duri g :inding, in predeeermined enguler positien will respect io .Lelie f" .riding Wheel airis; otherwise e lepered or irregularly shaped snriece is ground upon llie is accordingly ohjeci the inveniion to provide en improved inecliine for grinding relatively thin work herring e cylindrical surface.

Another objlec; lie invention is l rovision of means perni' g ehe pesseje of plurality of hin c; li--ciri3el work pieces., s c es hell recesa 'hrougn *elle machine in sucmanner that each Work piece bends o snpport and keep adjacent W rk in sueh posilion 'that e cui; when on 'the outside surface by the grinding Wheel will he parallel lo ille Work exis.

ing zone.

oe inedyiseole to wheel for cerryi, and it may he feeding mecha.. i

place ine feeding section of @Elie regulering Whse z l f i .f is iiiereore .rumoer osg-ec venion 'lo provide e oenterless grinding machine with e power driven feeding nieehenism capable el' moving e .plurality of pieces of work enielly zlirongh lie grinding zone and of maintaining die Work pieces in. alignment and properly'posiioned for grinding,

L is enoher object 'of the invention o provide e eenierless grinding machine in which he Wheel snes may he meineined perellel .ind the Worlf iiorced entoinsticeliy llirough the grinding1 sone loy en einernslly applied iorce or in which such 1force i my he employed lo assisi; and supplement the feeding action of *bhe reguleing wheel which nes iis exis slreWed .relative lo 'die exis of' ehe Work..

Fur'her oojeets will he epparen, 'o one skilled in ere.

ln accordance Wifzh ceriein 'features of `he invention, l provide .mechanism operatively associated Wieli the grinding Wheel and he I Work regulating Wheel of e cenerless grinding machine 'for positively moving cylindricel Work 'rowerd e grinding position loeeween the Wheels in e direction parallel so the eins of the Work. This Work may then be forced by such mechanism hrough the grinding zone while axially parallel with the regulating Wheel, but l prefer to shew this Wheel relative to lie Werl; so that the letter will be fed by the acion oi the Wheel after it has come in contese J:herewith end the pushing mechanism may in that easey serve .merely to supply the Work to the Wheels in proper position for grindingor, depending upon .the relative forces employedyto assist the regulating Wheel in moving the work through the grinding sone. My preferred form of pusher mechanism comprises :i Work guiding support and a pusher, operated oye weight or the like o nieve the worlr along the support. For this purpose, l may provide guide rails extending to or heween the Wheels and mounted parallel 'io `che axis or" the grinding Wheel. ll/leensrney he provided for causing e plureliy of Worlr pieces to travel inr conlect with erich einer along the rails oward ihe wheels o e grinding position. ln ac cordance with rny preferred practice, l move le "work along the rails in a practiclly out@ manner, or in 'timed relation to the movement of the work between the wheels during grinding. Preferably, I provide a movable carriage which isheld continuously under a pressure and engages the work to hold the pieces in contact with each other or to force them toward'a grinding position.

The invention accordingly consists-in theV features of construction, combinations of elements, and arrangements of parts, all as will be exemplified in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

The invention will be more clearly understood from the following description in conjunction with the accompanying drawings, in which is shown a preferred form of the various possible embodiments of this invention, and in which-g Fig. 1 is a front elevation of a centerless grinding machine embodying the invention;

Fig. 2 is a sectional view of a portion of the machine taken along the line 2`2 of Fig. 1;

Fig. 3 is a sectional view taken -upon the line 3-3 of Fig. 1;

Fig. 4 is a side elevational view of the machine in partial section and with parts removed or broken away; and

Fig. 5 is a detail view of the outwardly movable ngers on the movable carriage.

In the drawings, I have illustrated one type of centerless grinding machine embodyingl the invention and comprising a frame 5 in which suitable bearings are mounted for carrying a grinding wheel spindle 6 upon one end of which aY grinding wheel 7 is mounted. A driving pulley 8 is mounted upon the other end of the grinding wheel spindle 6 and isl rotated by means of' a belt 9 passing over a pulley 10 upon a shaft 11, drivenfrom any appropriate source of power. A work regulating Wheel 12 is mounted in any appropriate manner on a shaft 13-fitted in suitable bearings on the vertical arms of a V-shaped support 14 pivotally secured upon the top of the column 15. The water pan 16 surrounds the regulating wheel and is secured to the lcolumn 15 by means of bolts 17, passing' through thefiiange 18 on the column.V The regulating wheel` 12 normally is positioned with its axis skewed relative to the grinding wheel axis, but may be adjusted so that its axis is parallel to the axis of the grinding an arcuate slot 20 in the support 14 and 'into intermeshing bevel gears 28 secured on th`e.

55 shaft 24 and the work regulating wheel shaft wheel by means of a bolt 19-pas'sing throughl 13. The regulating wheel may be adjusted toward or away from the grinding wheel by means of a hand wheel 29 secured 0n one end of a shaft 30 and having an operating handle 31, the shaft 30 having a worm 32 on its other end engaging a worm wheel 33 on a screw shaft 34 passing through a threaded boss 35 on the pillar 21. A

In accordance with certain features of the invention, suitable means are provided for feeding cylindrical work pieces to a grinding position between the grinding wheel and the work regulating wheel in an axial direction and in predetermined relation to the axis of the grinding wheel, in this instance the axis of the work being parallel to the axis of the grinding wheel. This latter relation is preferred where the grinding wheel acts peripherally and is trued to substantially a true cylinder.` This comprises as illustrated blade-like members or work hold-- ing members located to support the work between the wheels and in operative contact therewith during the grinding operation, in combination with further guide rails along which the work is pushed by a pusher mechanism toward the grinding Zone. In the form shown, a plate 36 (Figs. 1 and 2) is secured upon each side 0f the pan 16 by means of bolts 38 within slots 39. The arms 40 are pivotally mounted upon the raised portions 37 of the plate 36 .to swing about a pivot bolt 41, and may be rigidly held inposition by lmeans of a bolt 42 ina slot 43. A pair of guide rails 44 are secured to the upper ends of the arms 40 by means of bolts 45, and pass between the grinding wheel and the work regulating wheel to guide thin cylindrical work to a grinding position. The slots 39 are shown as inclined at a slight angle to the vertical, so that as lthe plate 36 is raised or lowered the axis of the cylindrical work supported upon the rails 44 remains in substantially the same position laterally with respect to a line passing through the centers of the wheels, the preferred position being a short distance from such 'a line.

The portions of the guide rails 44 passing directly between the wheels are bent downwardlyor ground away slightly, as indicated in Fig. 4, so as to permit the work to engage the work regulating wheel 12 without contacting with these guide rails 44 but to contact with the members 46 and 47 (see Fig. 4) provided to hold the work correctly positioned during grinding. The work holdingmembers 46 and 47 are mounted upon the forwardly extending arms 48-secured to an auxiliary sliding frame having the rac-k 49 and may be adjusted up and down by turning the wheel 50 which is appropriately connected to a pinion (not shown) for moving the-rack. lThe arms 40 may be adjusted to move the rails 44 toward or away from each other by means of an adjusting screw 51 enthe rails'.

are adjustably mounted upon the carriageby means of bolts 62 and each carries a flexible or outwardly movable finger 63 (see Fig. 5) held in its innermost position by means of a spring 6d. rlhe end of each linger is adapted to engage the Work 65 upon The lingers are so located that they will exert a pressure at proper points adjacent the edge of the Work, and against the rear surface thereof, tending to keep the Work standing straight. 'lhecarriage 60 is movable toward the Wheels by the action of adjustable Weights 66 (Fig. l) suspended upon one end oi a cord 67 secured on a pin 68 on the carriage and passing over a pulley 69. rlhe carriage may be -inanually moved away from. the wheels by means (Fig. 3) of ahandle 70.

lt Will be understood that the Weight 66 may be adjusted so as to exert a torce against the Work pieces which is more than suilicient than that required to hold the vvorlt pieces against Work being ground. Thus, the

weight G6 may beniade heavy enough to actually push the Work piece being ground through the grinding zone.

l have obtained very satisfactory results in grinding thin cylindrical objects, such as ball races, brake shoes, and. the like, when the Work regulating Wheel 12 is skewed relative to the axis of the grinding Wheel through an angle of about l1/2 degrees. This is accomplished by loosening the bolt 19 4) and moving the regulating Wheel support ldto the required angle. rlhe guide rails le are secured upon the pan 16 so as to be .parallel with the line of contact of the grinding wheel with the work and, Where the grinding Wheel .is trued to a straight cylinder, they vv'ill also be parallel with the axis of the grinding wheel. rlhe position of the regulating Wheel 12 may be adjusted toward or away from the grinding Wheel to accommodate various sizes of Work by turning the hand Wheel 29 by ineens of the handle 3l (Fig. l) which actuates through an appropriate mechanism the screw 34 for raising or lovv'eringthe column l5. For diiie'rent sizes'of Work the position of the guide rails e4 inay be adjusted by turn- -ing the knurled knob 55 to move the adjusting screv:7 51. The position of the lingers 63 may be adjusted by loosening. the bolts 62 and sliding the arms 6l along the outer surface of the carriage 6G.

ln 'the grinding ot thin cylindrical obyects,

such as ball races, a suitable nuinber of Workpieces (indicated at 65 in Figs. l, 2 and 3) are placeduponand bet-Ween the rails ed (see Figs. 2 and 3) and the latter should be ladljusted to support the Worlr at a point, preterably, about one third the diameter of the Work away from the bottoni thereoi1 to steady the Worlt and oppose its tendency to twist. The carriage is moved to the right, as seen in l? ig. 1,'by the handle 70, thus raising the Weights 66, and is thus positioned along the member 56 to bring the fingers 63 in contact with the Vbach or rear end of the end-most Worlcpiece (the right hand end piece of the Workfpieces 65, as see-n in Fig. l) and the carriage 60 released, whence Weights 66 urge the latter to the left to keep the various pieces in contact with each other so that each supports its nent adjacent piece in position axially parallel to thel airis of the grinding wheel., or the Work being ground, and at the same time cause the workrpieces to be pushed along therails ld at"\the saine rate as the Work inoves between thewheels during grinding. The preferred arrangement and action of 'the several parts of the apparatus are Vsuch that the regulating Wheel 12 predetei'inines the rate of axial feeding movement of the Work-pieces 65 as the latter pass through the grinding throat, and that the carriage 60, in moving toward the left, as seen in Fig. l, under the urge of the Weights '66, causes such Work-pieces 65 as arefto the right of the grinding throat to steadily follow up such Work-pieces as are being fed through the grinding throat by the regulating wheel l2, at the saine time preventing the Workpieces 65 that are outside of the grinding throat from tilting, and thus insuring that they are presented to the grinding throat pren cisely and accurately in alineinent with the elementsofthe grinding thro-at. llhile the plurality of thin Worlt pieces are being pushed toward their grinding position between the wheels, additional Work pieces may be loaded upon the rails in back of .the ngersl and between thearnis 6l (Fig. 1).` lhe'se may be pushed against the work previously placed upon the rails by drawing the carriage in a n direction away from the wheels by means of the handle 70 so that the fingers engage the last Work piece. yln so doing, the flexible.`

are pushed forward due to the action of the".`

weightsl 66 tending to move the carriage 60 toward the Wheels. v

Nh'enthe work piece has progressed along the rails'ed until it reaches the bent or ground away portions of the rails, these portionspermit the Work to drop downwardly a short izo distance into engagement with the regulating wheel, which, as may be seen in Figure 1,-has a greater width of operative surface than the grinding wheel, and projects outwardly beyond the grinding wheel toward the advancing work pieces. Assoon as the work pieces leave the rails 44 and engage the regulating wheel surface they start to rotate, and they are thus in rotation when they enter the grip of the two wheels; thereafter, the work pieces, continually rotated by the regulating wheel and being ground by the grinding wheel, move through the grinding zone heldin position by the members 46 and 47. The work does not contact with the rails while being ground but as it continues through the machine and leavesthe regulating wheel it may be and, preferably, is `again supported by the rails, which guide the same to an appropriate, point of discharge, such for example as a discharge trough 7l.

The machine illustrated is particularly adapted for grinding a succession of discs, such as ball races, which are passed through the machine in a practically automat-ie manner and in such away that each disc tends to support and keep its neighbor disc upright so that the cut taken on the outside surface will be at right angles to the sides, or parallel to the work axis. rlhe pressure of the carriage, or the flexible fingers carried thereby, in forcing the discs into a position for grinding, preferably, is just sufficient to keep a constant in-pressure on the discs so that there is no gap between any two discs at the time the control orwork regulating wheel starts to give motion to them and carry them through the machine. I have obtained satisfactory results with the parts of the machine so constructed and arranged that there is no actual pushing of such thin work during grinding and the carriage` does not tend to skid the work across the regulating wheel. a

It is to be understood that this machine will handle relatively long or thick pieces of work and that it is not limited in use `to the grind- 'ing of discs. But it will be seen that many thoroughly practical advantages are achievedwhen the apparatus operates upon workpleces whose axial length is relatively small compared with the diameter thereof. Moreover, in accordance-with the above disclosure, the weight 66 may be increased to such an extent that it will help the skewed regulating wheel force-the work past the grinding'wheel.

If desired, the regulating wheel may be located with its axis parallel 'with that of the work, and in that case the regulating Wheel l2 will not feed the work axially but 'then the weight 66 may be so adjusted that it will serve alone to push the work through the grinding Zone.

It will thus be seen that there has been provided in this invention an apparatus in which the several objects hereinabove noted,

rsaaeai vantages, are successfully achieved, and it will be seen also that the apparatus is well adapted to meet the varying conditions of hard, practical use.

As many possible embodiments may be made of the above invention and a's many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. In a grinding machinein combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed, means for holding between said wheels and in operative relation thereto a succession of thin cylindrical work pieces positioned face to face` the path of travel of the face of said regulating wheel being inclined with respect to the axis of the work thereby to ex- .ert an axial feeding vcomponent upon the work, and means adapted to bear yieldingly in an axial direction against said work pieces to hold their adjacent end faces in Contact whereby said work pieces tend to support each other against twisting.

Q. In a grinding machine,fin combination, a grinding wheel adapted to be rotated at a. relatively high speed, a regulating wheel .adapted to be rotated at a relatively low speed, means for holding work between said wheels and in operative relation thereto, the pat-h of travel of the operative face of the regulating wheel being inclined with respect to the axis of the work to exert an axial feeding component upon the work, and a work presenting mechanism including means for supporting a plurality of pieces of work, and

meansadapted to move said work pieces speed, means for holding Work between saidy wheels and in operative relation thereto, supporting means mounted substantially parallel to the axis of the work being ground for carrying pieces of work toward the wheels,

`and reciprocable means for feeding contacting work pieces along said supporting means to a grinding position, said reciprocable means having a Work-feedmgstroke sutiiclent ireletively liigli speed Les? ' f regiiletinfg;- Wheel being inclined with respect to the exis of the Work to exert enamel feediing component upon the Work, ineens Jfor varying tbe inclination between tbe anis of tbe Work ,en the path of travel of 'lille operative face of the regulating Wheel to very the rete oie exiol feeding movement oi the Work,

ineens for feeding e succession oi Worl pieces toward e. grinding position et substantielly tbe seine retev as tbe vvork being ground is moved axially by tbe regulating Wheel and operating tlius even though the rete ofi feeding movement by the reguletinw wheel is veriecl and for holding tbe oi: the vvorlr being ground against twisting.

5. n grinding machine, in combination., grinding Wlieel adapted to be roteted et e.

vRelatively high speed, e regulating wheel adapted to be rotated et e relatively lon-v speed.s ineens for holding Work between seid Wheels incl in operative relation thereto. Ineens for supporting e.. succession of Work pieces with their aires entencling in substantiel riliineinent with tlie anis oi e Work-piece beingX opereteol upon by seicl Wheels and. 1for entrance axially into e. grincling position be-I tween Wheels, e inoveble carriage operatively associated with seid supporting, ineens,v ene ineens for applying yiel liable- `=ee to seiel carri-ege for moving seio. eerto liolcl the Work pieces in Contact vvbile moving tbe seme along seicl snpgorting ineens to e. position for grinding.

i n e grinding machine, in combination, .grinding Wheel sclepecl to be rotated et e letively liigli epeel9 e regulating Wheel mente@ to be rotated et e reletivelgT low speed. ineensvfor holding vvorlr between seid Wheels :incl in operative relation thereto..

ineens for supporting e succession of Work pieces with their axes extending in substantiel elineinent i ith the airis of e Work-piece being operetecl upon by seid Wheels endl for entrance axially into e griniing position between seicl Wheels, e. carriage for moving the Work pieces along seid supporting ineens, enel ineens for applying en adjustable force to move seicl @ariege enel to' liolcl tlie Work piecee in Contact with ezioli other.

7. ln e grinfling machine, in combination. e grintiing wheel adapted to be rotated at :i relatively liigli speed, e regulating-Wheel eflep'teil to be ,rote-ted et a relatively low speed. ineens for holding Work between seicl Wheels sind in operative relation thereto.,

- ineens for supporting e. suecession of Work Worlg and ineens for moving seid carriage to l'iolcl tbe Work pieces in Contact on seid snpportingg' ineens While moving tlie seine tov-.feral :L grinding position.

8. ln e grinding ineoliine, in conobnietions L grinding Wheel ecleptefl to be rotated at e,

relatively liigb spee, e regulating Wheel adapted to be rotated at e. relatively low Speed, ineens for holding Worli between said Wheels and in operative relation thereto., ineens ior supporting e succession o1? Work pieces for entrance axially into e grinding position between seid Wlieels7 e oerriege operatively essoeietetl with seid supporting means incl adapted to inove toiveril enel away from szlicl Whe-els and bei projecting iingers adopted to engage tne Work nieces on said. supporting ineens, ineens 'or ecljnsting said linge-rs towarel'end muy from eeob other for engaging Work pieces oi various sizes, anal ineens for moving Carriage to bold tbe Work pieces in cont et While movin the seine along seid supporting ineens tenersi grinding; position. A

9. in grinding; nieebiifie7 in eornbinetion e' grinding vvlieel adapted to be rotated at e relatively bigb speed, e. regulating Wheel positionecl below seid. grinding Wheel and eelepreel to be rotetecl et e relatively lov? speed, ineens for holding vork between sail Wheels end in operative relation thereto, ein?. ineens for iieeoling succession off thin ey- 'linlricel Work nieces toward e grinding position., seiol ineens holding` an end-moet Workpiece with its anis snbstentielly aligned Witli e Work-piece beine; ground enfl inovingwitli seid enel-most Work-piece for maintaining tbe axis 'of the remaining Work-piece .against tilting.

l0'. ln e grinding; niecliine. in combination., e periplierelly operative grinding Wheel efiepted to be rotated at a relatively high speed. e regulating Wheel positioned below seiil grincling Wlieel enel ofleptecl to be rotated et o. ieletively low Specfli Ineens for holding work between sziicl Wheels incl in opeietive reletiontbereto, ineens mounted substantially pere-.Hel to tbe exis of the grinding Wlieel and nrrsngecl to carry cvlinflrioal 'Work pieces onto tlie regulating Wheel to be rotated thereby during` grinding. incl ineens for pushing the worn pieces into Contact enel along' Seial lest ineens toward e grinding position.

' at a relatively high speed, means coactingy cylindrical Work pieces in position :tor movement aXially into operative relation to said Wheel, and poiver-actuated means adapted to feed said Work pieces axially along said Supporting means toward grinding position and movable With said Work-pieces to support said thin pieces against titlting out of proper axial relation to said grinding Wheel as they move into operative engagement with said grinding Wheel and said Work-holding means.

12. In a grinding machine, in combination, a grinding Wheel, means for holding work with itsv periphery in operative relation thereto and adapted to take up the thrust of the grinding Wheel on the Work, means for supporting a succession of thinlcylindrical Work pieces in position Vto: movement axially into operative relation to said Wheel, a carriage movable alongsaidsupporting means,.

meansupon said carriage adapted to bear against I,the end face of the rearmost work piece, and. means -for moving said carriage to force said Work pieces along said supporting means and into operative relationito said wheel and said Work-holding means.

13. ln a grinding machine, in combination, a grinding Wheel adapted to be rotated therewith for supporting cylindrical Work pieces in operative engagement with said grinding wheel and for rotating said Workpieces, said means including a rotary member adapted to be driven at a relatively low speed and having a portion extended beyond the. operative race of said grinding Wheel, means `for supporting cylindrical Work in position for movement axially into operative engagement 'with saidigrinding Wheel, and means for feeding said Work along said supporting means and into engagement with said extended portion of said rotary member to be rotated thereby preliminarily to 'its entry Yinto operative `relation to saidv grinding Wheel. y

14. lin `a grinding machine, in combina- '.tion, a grinding vvheel adapted to be rotated at a relatively high speed, means for supporti ing a succession or thin Work pieces for entrance axially into operative engagement with said grinding Wheel. means adapted to move said Work pieces along said supporting means and to holdthem againsttilting out of `proper axial position `for grinding, and means adapted to receive said Work pieces from said. supporting means and to support and rotate said Work pieces in operative relation to" said' grinding wheel, said last means including a rotary member adapted to be rot-ated at a relativelylovv speed and having a portion extended beyond the face ot the grinding Wheel in a direction tovvard` the advancing Work pieces whereby said Work piecesare rotated preliminarily to their entrance into operative relation with said grinding Wheel.

:toevoer 15. ln a grinding machine, in combination, a grinding Wheel adapted to be rotated at a relatively high speed, a regulating Wheel adapted to be,rotated at a relatively low speed and positioned beneath said grinding Wheel, and means adapted to support a succession oi cylindrical vvork pieces for en` speed and positioned beneath said grinding t wheel, and means adapted to support a suc' cession of cylindrical 'Work pieces for entrance axially into the grinding zone between said two Wheels and at an elevation slightly higher than the portion of said regulating Wheel which engages the Work, said regulatingwvheel being extended beyond the tace of the grinding Wheel and the extended portion thereof being adapted to receive the Work pieces dropped thereon from said supporting means, and means adapted to hold the work pieces in position for proper engage -ment by the grinding Wheel and the regulating Wheel as they pass through the grinding zone.

17. ln a rinding machine, in combination, a grin ing Wheel adapted to be rotated at a relatively high speed, a regulating Wheel adapted to be rotated at a relatively low speed and positioned beneath said grinding Wheel, said regulating Wheel having a portion extended beyond the face ofthe grinding Wheel, means adapted to deliver cylin drical Work pieces axially to said extended regulating Wheel portion and at an elevation slightly higher than the portion of said reg-` ulating Wheel which engages the Work, and means adapted thereafter to holdsaid Work in position for proper engagement by the grinding Wheel and the regulating Wheel as it passes through the grinding zone.

18. ln a grinding machine, in combination, a grinding Wheel adapted to be rotatedY at a relatively high speed, a regulating' wheel` adapted to be rotated at a relatively low speed, means for holding `Work between said Wheels and in operative relation thereto, and means for feeding a succession of Work pieces for entrance axially into a grinding position between said wheels, I'said last means including an elongated support along which the work pieces are adapted to slide axiallvand a carriage slidable in a directionflengtliwise oi said supporty and adapted to push the work pieces into operative position between said wheels, the carriage being arranged to permit placing additional work pieces on said support rearwardly of the carriage as the cartriage advances. A

19. ln a grinding machine, in combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel tij adapted to be rotated at a relatively low speed, means for holding work between said wheels and in operative relation thereto, and means for feeding asuccession of work pieces for entrance axially into a grinding position between said wheels, said lastineans including an elongated support along which the work pieces are adapted to slide axially and work ieces and ada ted to enoaoe the rear D 1'* end of the work pieces to urge them along said support, said fingers being arranged to swing outwardly and clear the work pieces rearwardly of the carriage as the carriage is moved rearwardly.

@Oi ln a grinding machine, in combination, a grinding wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed,

means forholding work between said wheelsy and in operative relation thereto, means for supporting a succession ot' work pieces 'for entrance axially intoa'grinding position between said wheels comprising two rails spaced apart and adapted to engage the sides of' the work pieces below the axes thereof, means for adjusting the position of saidlrails to accommodate work pieces. of different sizes` and means for forcingl the work pieces along said rails to feed them into grinding position,

2l. ln grinding machine, in combination,

a grinding wheel adapted to be rotated at a' relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed, means for holding work between said wheels and in operative relation thereto, means for supporting a succession lof work pieces for entrance axially intoa grinding position between said wheels, a carriage operatively associated with saidv supporting means and movable lengthwise 'thereof and adapted to hold the work pieces in contact with each other and move the same along the supporting means to a position for grinding, a weight for moving said carriage in a direction to feed said work pieces toward grinding position, and a handle for manually re tracting said carriage.

22. ln a grinding machine,in combination,

agriniing wheel adapted to be rotated at a relatively high speed, a regulating wheel adapted to be rotated at a relatively low speed, means for holding work between said wheels and in operative relation thereto, means for supporting a succession of work pieces for entrance axially into a grinding position between said wheels, a support positioned beneath said work supporting means, and a carriage on said last support and movable thereon in a direction lengthwise of said worksupporting means, said carriage having an upwardly projecting part adapted to engage the work pieces and move them along the work supporting means when the carriage is moved.

23. ln a grinding machine. in combination, means forming a grinding throat for simul- Itaneous rotating and grinding action upon work-pieces of round section and including a regulating wheel rotatable at relatively low speed and adapted to control the rotation of ,the work and-a grinding wheel rotatable at grinding speed for performing the grinding operation upon the work; means for guiding work-pieces into said grinding throat; means movable toward and away from said grinding throat and adapted, upon movement toward said grinding throat, to move a workpiece positioned in advance thereof along said guiding means and into operative relation to the grinding throat. said movable means exposing a portion of said guiding means to the rear thereof for the reception of an additional work-piece; and meansv causing said movable means, upon movement in a ,direction away from said grinding throat, to oy-pass said 'additional work-piece.

24. ln a grinding machine, in combination, means forming a grinding throat for simultaneous rotatingand grinding action upon work-pieces of round section and includingr a regulating wheel rotatable atrelatively low speed and adapted to control the rotation of' the work and a grinding wheel rotatable at` grinding speed for performing the grinding operation upon the work; means for guiding work-pieces'into said grinding' throat and adapted to guide a succession of work-pieces: and means movable along said guiding means and in a direction toward and away from said grinding throat and adapted, upon 'pieces, said movabley means being constructed to by-pass said last-mentioned succession of work-pieces when it is moved in a direction away from said V,grinding throat, whereby means *forming a grindingla throat for simulsaid second-mentioned succession of Workpieces becomes positioned in advance of said movable means. y

25. lin agrinding machine, in combination,

means forming a grinding throat for simulvtaneous rotating andgrinding action upon Work-pieces of round section and including a regulating Wheel rotatable at relatively low speed and adapted to control the rotation of the work and a grinding Wheel rotatable at `grinding speed for performing the grinding operation upon the Work; means for' guiding Work-pieces into said grinding throat; means movable toward and away from said grinding throat to move a Work-piece positioned in advance thereof along said guiding means and into operative relation'to the grinding throat, said movable means exposing a portion of said guiding' means to the rear thereof for the reception of an additional Work-piece; and means for yieldingly supporting the Work-engaging portions of said movable means and adapted to permit said portions to clear said additional Work-piece as said movable means is moved away from said grinding throat.

26. In a grinding machine. in combination` taneous rotating and grinding actionv upon work-pieces of round section and including` a regulating wheel rotatable atl relatively low yspeed and adapted to control the rotation ot ,the Work and a grinding` Wheel rotatabie at ,grinding speed for performing the grind-ing operation upon the Work: means er:- tendine; away from said grindingq throat 'and substantiallv inthe direction of the axis ot y the Work-piece operated upon 'for retainine;

a successionot relativelv thin cylindrical Work-pieces and guiding them in an axial direction into said ,qrindinfxy throatzand movable means engaging an end Work-niece of said succession for moving* said lsuccession toward said grinding' throat as the grinding throat performs its operation.

2?.' ln a mindingr machine. in combination., means termina" a grinding: throat for simultaneous rotating and grinding action upon Work-pieces oi'round section and including a regulating: wheel rotatable at relatively low speed and adapted to .control the rotation of the work and a grinding "Wheel rotatable at grinding speed i'or performing the grinding' operation upon the Work; means extending away from said grinding throat and substantially in the direction of the axis of the Workpiece operated upon for retaining a succession of relatively thin cylindrical Work-pieces andfguiding them in an axial direction into said grinding' throat; a device engagginga work-piece in said succession remote from said grinding throat and movable in a direction toward the latter; and means causing movement of said device to eiect movement lof october, 1925.

nsaagsai of said succession of Work-pieces successively into said grinding throat. y

Signed at Detroit, Michigamthis 12th day HAnoLniW. HoLMns.

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