US1757612A - Centerless grinding machinery - Google Patents

Description

vcs. w. BlNNs-ET AL 1,757,612

May 6, 1930.

CENTERLESS GRINDING MACHINERY 3 Sheets-Sheet 1 Filed Aug. 24, 1925 nuenoni May, 1930. f G. Aw. BINNs ET AL 1,757,612

CENTERLESS GRINDNG MACHINERY Filed Aug. 24, 1925, 3 Sheets-Sheet 2 61H0: new

May 6, 1930. G. w. BINNS ET Al- CENTERLESS GRINDING MACHINERY Filed-Aug. 24, 1925 3 Sheets-Sheet 3 glu ucnhwg, Geary@ [l1/" 21 21s Patented May 6, 1930 4UNrrlgzo STATES4 Pzlvrnlsrr OFFICE l GEOReE w. RINNs, or.' CINCINNATI, AND WALTER n. ARCREA, OF NoRwoon, 01110,v

AssIeNoRs, BY'MESNE ASSIGNMENTS, rro CINCINNATI GRINDERS INCORPORATED, or CINCINNATI, OHIO, A CORPORATION or ORIO CENTERLEs's GRINDING iilrAcrrINERv- Application led August 24, 19.25. Serial No. 52,056. i 1)" This invention relates to improvements in centerless grinding'machinery and has paricular reference to' novel and improved mechanism for supplying workpieces to such ma- `chines and assuring proper discharge of the completed workpieces.

One of the ob]- eots of the presentv invention is the provision of improved'mechanism for use in connection with a centerless grinder o which will facilitate the successful supplying of individual workpieces in operative position within' the machine.

A further object of the invention is the provision of a mechanism particularly adapted for the handling of small workpieces which will relieve the machine operator of the difficulties ordinarily attendant upon direct hand feed of the parts into the machine.

, Another object of the invention'is the provision of a structure which will make itpossiblesto insure continuous operation of the fmachine and constant supplying of workpieces thereto while permitting of initial preparation of the pieces at a point distant v from the machine.

An additional object ofthe invention is the provision of novel and improved mechanism for use inthe in-feed method of centerless grinding which will successively position the individual workpieces in operative position inthe grinding throat.

Other objects include the provision in infced grinding mechanism of a novel and improved method of. positioning and handling workpieces during form grinding and a general simplification of the structural details,

while preventing breakage of the parts in event of jamming of the workpieces.

foregoing objects vand 4structure for accom- 4.o plishment thereof should be readily understood by' reference to the following specification taken in connection with the .accompanying drawings, and it will'be understood that We may make .any modifications in the specific structural details shown and described Within the scope of the appended claims Without departing from lor exceeding the spirit of the invention.

L Figure 1 is a side elevation of a machine. embodying the invention.

The

Figure 2 is a vertical sectional view with parts broken away. l

Figure 3 is a horizontal sectional view as on the line3-3 of Figure 2.` l Fi re 4 is a section on the line 4-4 of said gure. s

Figure 5 is a transverse section on the line 5--5 of Figure 2.

vFigure-6 is a similar section on a diii'erent plane to bring out the` action of the lower cam member.`

Figure 7 is a front elevation of the removable magazine.

Figure 8 is a perspectiveview of the maga- Figure 14 is a perspective view of the feed- I controlling double cam member, and y Figurel is a fragmentary perspective view of the workrest..

The present inventiondeals primarily with what islknown as in-feed centerless grinders, which is to say grinders in which the work is introduced within, acted upon and subsequently .discharged from the grinding throat by other than a continuous axial movement of the workpiece. In the present invention these results are intended to be -automatically attained by suitably supplyingindividual workpieces from a magazine, axial y introducing the workpieces into the`grinding throat when the wheels are Ain a separated position, subsequently bringing the wheels together to operate upon the work nand then separating the wheels a suicient amount to allow the workpiece to vdrop down between the'wheelsandbe discharged from the machine. The particular mechanism for caus- V ing this opening and closing movement of the wheels has been specifically illustrated and Claimed in ojo-pending application Serial No. 102,762, filed April 28, 1926, for example, and is not, therefore, particularly described.

In the embodiment of the machine 'chosen for illustration of the invention A desig- ,dle H or by the mechanism indicated at' I as driven by the motor K, Attention is invited to the co-pending application above referred to.

It will be noted that the grinding wheel B is shown as adapted forl what is known as form grinding, that is tosay .that it has a central plain portion as at 2() with beveled lateral portions as at 21. A wheel of this configuration operatingupon a cylindrical workpiece will produce apiece having a central plain cylindrical portion 22 and cone point i ends 23 as shownin Figure 3. To retain the work against the grinding wheel and to control'the speed of rotation thereof, use 1s made of a regulating wheel E having a .plain work-engaging surface 24 engaging the cylindrical portion`22 of the workpiece it being unnecessary for the regulating wheel to engage the shaped end portion 23. To facilitate axial introduction of the workpiece into the grinding throat theregulating wheel is beveled on the entrant side as at 25. In ordiblank, the workpiece may be pushed between the two wheels, its 4pointed end 23 being guided into. position by contact with the bevj eled portion 25 of the regulating wheel. The

required. separation of the wheels for this purposeis shown in Figure 11.

To support the work within the grinding throat 4between wheels' B and E use'is made of a workrest or support preferably carried by slide.C and including a bracket portion 26 and a shaped work-receiving portion 27 having its surface inclined toward the 'regulating wheel and atop configuration substantially corresponding to the contou'rof the worktorest thereon.V `As the present machine is designed to operate upon-workpieces of quite small diameter the rest or support is made from a heavy piece of material and is centrally cut away or relieved as at 23 and 29 i to receive the grinding and regulating wheels respectively, as should be readily un erstood by reference to the views on sheet 3 of the drawings. The width of the workrest is such that when the wheels are partly separated for introduction of the workpiece the rest will still support the work within the throat, while as the wheelsare brought into operative engagement with the work, the work; piece will ride up on the inclined surface at 27. When the wheels are. subsequentlyseparated a greater distance the work will be discharged dropping down through the channel at 29 as shown in Figure 13.

Machines of the general character here described are designed for automatic productionof workpieces accurate to within a fractional thousandth of an inch and at maximum rate. To attain this speed of production it is desirable that the work be automatically fed into the grinding throat. For this purpose the present invention includes a supporting block 30 carried by bracket 26 andA having inv v its face a work-receiving groove 31 covered by faceplate 32 forming a vertical passage of size to receive a single row of workpieces. In order that a continuous supply of'workpieces may be supplied to said passage and thence to the grinding throat use is made of the removable work-receiving magazines. Such magazines comprise a back plate 33 having the work-groove vor passage 34 and hav- 4inghinged thereto the front or cover plate 35 fastened in closed position as by thumb nut 36. The cover plate has a plurality of sight apertures 37 for observance of the movement of the workpieces inthe magazine.

'It is intended that a plurality of inter changeable magazines be employed. each being provided with a positioning groove or recess 38 on its rear face for interlocking engagement with a tongue 39 on block 30 to accurately position the magazineI for alignment of work-passage 34 with the passage 31 of block 30. To facilitate quick interchange of the magazines, block 30 has lug 40 in which is journaled the rock shaft 41 'provided with 'a manually actuable handle 42 and with the cam portions 43 which as the handle is rocked will force the removable magazme against tongue 39 and lock same in position as best illustrated in Figures 4 and 8.

It will be understood these magazines are filled with the workpieces to be operated upon and then brought into the machine. To 'prevent loss of workpieces from the discharge end of the magazine during handling, use is made of spring-keeper 44 having retainer 45 normally extending transversely of passage 34. This keeper is of greaterlength than 'the magazine so that when the latter placedin position against block 30 and the locking cams tightened, the front face of the block below the magazine receivingfshelf 46 will engage the projecting end of the spring pressing it outward to withdraw stop 45 and allow downward movement of the workpieces as illustrated in Figure 4.

Coupled with the automatic regulating wheel reciprocating mechanism I as at 47 is' rock-shaft 48 having rigidly secured thereon actuating cam 49 adjacent which is loosely mounted rock-arm v50'. .Arm 50 `bears the yieldably mounted plunger 51 engaging cam 49 whereby clock-wise rocking of .shaft 48 will exert pressure against plunger ltending to swing arm 50 to the right but permitting movement of the shaft without movement of the arm in case an oversize workpiece or other obstruction prevents the customary and desired operation of the arm. Tension on the plunger may be varied by adjustment of cap-screw 52.

To rock arm 50 in the opposite direction a definite ampunt, an adjustable screw mem` -ing throat as is indicated in Figures 3 and 9 of the drawings. In the feeding action the workpieces may either be allowed to move downward as .an

entirety against the ejector pin so that the lowermostwill be in position to drop in`ad vance of the pin in its retracting movement 1n each instance, or use may be made of the special feed control mechanism here illustrated. This mechanism includes a pair of stop plates alternately projecting into the pat-h of discharge of the workpieces andl cam means for automatically regulating the movement of these stop plates. Secured to bracket 26 is a guide bloc-k 60 within which isslidably mounted the .pair of plunger members 61 and 62 having the double beveled contacts 63 and 64 respectively adapted for engagement with the cam faces 65 and 66 of the upper cam and 67 of the lower cam. Springs 68 and 69 urge the plungers inwardly tending to press their respective stop plates 70 and 71 transversely of the work-passage 31 thus preventing downward movement of the work-pieces therein. As slide 57 is shifted tothe right or in workinjection position, cam 67 will strike contact 64 moving plunger 62 rearwardly and withdrawing stop plate.71 from the path of movement of the workpieces. Ilr this event, 1f

there is a workpiece resting on stop plate 71,

the workpiece can drop down into alignment with the feed plunger- 59 as is shownin- Fig- A ure 4. During thismovement plunger 61`is stationary.` On the withdrawing movement ofthe slide, contact 64 will ride down on cam4 67 allowing stop plate 71. to move into closed position. Subsequent to this movement 'cam 65 will engage plunger 63 rearwardly thereabove moving stop 70 so that a workpiece may drop down and rest upon'stop plate 71.

On the return or feed movement" stroke cam 66 will again move plunger 64 backward but as one workpiece will be resting'upon stop 71 the lowermost workpiece adjacent plate 70 can merely move into a position where it will be clamped between the end of the stop and the side wall'of the passage as shown in Figure 4, being then ready for quick downward movement onto. the lower stop plate on the next return stroke. In this manner the delivery of small diameter workpieces is accurately controlled. and liability' of jamming or piling-up of the workpieces or introduction of more than one workpiece at a time into alignment with the injector is prevented.

From theforegoing description the construction and method of operation of the machine should be readily apparent and it will be seen that there has been provided an improved automatic mechanism by which small individual workpieces may be fed in n continuous stream in proper sequence to thegrinding throat and in which the grinding, ejection, and introduction of new workpieces is performed in proper sequence and satisfactorily formed articles'of desired configuration properly produced at a rapid rate by the in-feed grinding method.

vParticular attention 'is invited to the automatic cyclic operation of themachine in which the regulating wheel is moved back from the grinding wheel and work rest a sufficient distance to allow a completed work lou piece to roll off the work rest and down through the discharge groove 29. Subsequently the wheels are brought together a suiiicient amount to lretain the work piece between regulating wheel and work rest at which time a work piece is forcibly laterally introduced into the grinding throat by the automatic work injector, after which thi` throat is decreased in width to properly.

grind the Work piece and then opened up to permit of discharge thereof.

El.V A centerless grinder including a grinding wheel having a centrally recessed peripheral face with projecting side flangesl and a regulating wheel having a plain portion oppos1n`g the centrally recessed face of the grinding wheel and having a beveled portion adjacentone of the flanges of the grinding wheel as an entrant guide for work introduced between the wheels and means for between-the wheels, means for imparting a relative in and out movement to the wheels to open the grinding throat sufliciently to allow a workpiece to be axially introduced between the iiange of the grinding wheel and the beveled portion of the regulating wheel and means for axially introducing a work piece transversely ofthe opposed faces of the wheels and guided by saidbeveled portion.

3. The combination with a centerless grinder `including opposed grinding and regulating wheels, of a work-receiving magazine supported adjacent the wheels, a plunger carried by the grinder for shifting work from the magazine to the grinding throat between the wheels, means for actuating the plunger and a yieldable safety device in the actuating means. l

4. The combination with a centerless grinder including opposed wheels providing a work-receiving throat, of an ejector plunger carried by the grinder for shifting work into the throat, a positive actuating device for the plun ger, and a yieldable coupling between the plunger and actuating device permitting movement of the actuating device without shifting of the plunger when the path of the i plunger is obstructed.

5. A feed mechanism for a. centerless grinder including a work-feeding plunger, a chute for delivering work to the plunger, a plurality of work stops projectable into the pat-h of movement of workpieces through the chute, means for automatically shifting the stops into and out of said path of movement, said means including independent cam members 4for the several stops, said cam members being movable with the plunger to cause the actuation of the stops to occur in timed relation-with the movements of the plunger.

6. A centerless grinding machine including opposed grinding and regulating wheels, the grinding wheel having a recessed formed face and the regulating wheel having a. plane portion opposing a portion of the formed face of the grinding wheel and a bevelled portion in the entrance side to provide a work guide, of

means for automatically opening and closing the throat between the Wheels and work sup.

plying means disposed adjacent the grinding throat in offset relation to the axial position of the work within the throat, whereby a work piece projected therefrom will engage the bevelled entrant surface ofthe regulating wheel and be guided between the wheels thereby and subsequently displaced to engage the contoured portion of the grinding wheel upon closing of the grinding throat and means for automatically transferring a work piece from said off-set work supplying means to the grinding throat in timed relation to the opening and closing of said throat.

7. A c enterless grinder, including a bed, a grinding wheel supported thereon, an opposed regulating wheel mounted for in and out movement relative' to the grinding wheel, a work guiding member mounted on the bed adjacent the grinding throat between the wheels and having a discharge portion axially alined with the regulating wheel when in its retracted position, a plunger member for shifting Work from the guide into the grinding throat, magazine retaining means carried by the work guiding member for securing a magazine inposition to feed work thereto, a plunger for shifting individual work pieces from the work guide to a position within the grinding throat and means coupling the plunger with the regu-lating wheel. iecipro-v eating mechanism to cause injection of a work piece in timed relation to the movement thereof and while said wheel is ina-retracted position.

' 8. 'A eeiiterless grinder, including a bed, a

grindingv Wheel supported thereon, an op-V posed regulating wlieel mounted for in and out movement relative to the grinding wheel, a work guiding member mounted on the bed adjacent the grinding throat between the ywheels and liavmg a discharge portion axially alined with the regulating wheel when in its retracted position, a plunger member for shifting work from the guide into the grinding throat, magazine retaining means carried by the workguiding member for securing a magazine in position to feed Work thereto, a plunger for shifting individual work pieces from the work guide to a position within the grinding throat, and means coupling the plunger with the regulating 'wheelreciprocating mechanism to cause injection of a work piece in timed relation to the Vmovement thereof'and while said wheel is in a retracted position, the plunger havingcam portions controlling step -by step movement of the work pieces in the guide toward the path of the work shifting portion of the plunger in timed relation to the operation thereof. Y

9. An automatic machine for'centei'less grinding, including a bed or support, opposed grinding and regulating wheels carried thereby, said grinding `'Wheel having a recessed contoured surface, a Work rest meniberdisposed adjacent said surface, having a portion of reduced thickness providing a 'work support adjacent the grinding wheel and a discharge trough leading therefrom, means for automatically imparting an in and -out movement to the regulating wheel as respects the grinding wheel by way of said trough, whereby said regulatlng wheel will serve in combination with the restto retain a work piece in position, to press the work piece against the grinding wheel or when Y with-drawn to permit discharge' movement of the work piece through the trough, a

work guiding member disposedadjacent the grinding throat and having adischarge portion aligning with the regulating wheel in its intermediate work retaining position, means for supplying work pieces to said guiding member, and meansffor shifting individual work pieces therefrom into the grinding' throat in timed relation to the movement of the regulating wheelu 10. A. centerless grinder including a bed,

Y a'grinding wheel carried by the bed for op- Yso eration at a high or -grinding rate of speed, an opposed regulating wheel carried by the bed and rotatable at a slow work controlling rate of speed, a work rest projecting into the throat between the grinding and regulating wheels, means for automatically separating the wheels a suicient distance to permit a completed work piece to roll oivthe work rest in the direction o the regulating wheel, for subsequently closing the throat anL amount suicient toprevent such rolling of the work, and means for positively axially introducing a work iece in the throat when the parts are in sai retaining position.

l11. vIn grinding apparatus, in combination,a grinding wheel rotated at grinding speed, a regulating wheel opposed thereto and rotated 'at a relatively low speed and in a direction to present an operative surface traveling in a direction opposite from the direction of travel of the adjacent grinding wheel surface, a work support extending between said wheels, means for approaching and separating one wheel relative to the other, a magazine for-holding a supply of work pieces and .positioned to permit discharge of a work iece therefrom onto'said work support but splaced axially from the position which the work piece is to/'occupy when operated upon by said two wheels, a plunger movable in a direction lengthwise of the axis of the work piece for moving a work piece discharged from said magazine into operative relation to said two wheels,

mechanism for eEecting discharge of work c pieces one by one from said magazine, and means for actuating in predetermined sequence said wheel 4a]g pr`oaching and separating means, said plunger, and sai-d mechanism.

' GEORGE W. BIN NS.

WALTER D.. ARCI-IEA.

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