US2205468A - Centerless grinding machine - Google Patents

Description

June 25, 1940.

R. H. CRAMER CENTERLESS. GRINDING MACHINE Filed Oct. 2, 1939 INVENTOR;

12/4 YMOND H, 0 A Mill HIS ATTO RNVE Y. I

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Patented June 25, 1940 UNl'lED STATES 2,205,468 7 CENTERLESS GRINDING MACHINE Raymond Ill. Cramer, Newark, N. 3., assignor to General Motors Corporation, Detroit, Mich, a

- corporation of Delaware Application October- 2, 1939, Serial No. 297,510

16 Claims.

This invention relates to centerless grinding machines and comprises all of the features and aspects of novelty herein disclosed. An object of the invention is to provide improved mechanism for grinding tapered articles, especially bearing rollers which are conical or have their peripheral surfaces generated by a curved surface of revolution, one end of the roller being larger than the other. Another object is to provide improved mechanism for presenting tapered work to a centerless grinding machine and giving the work a lateral cross feed movement against the grinding wheel without raising or lowering the work with respect to the line of wheel centers. Another object is to provide improved mechanism for feedingtapered work to and ejecting it from a centerless grinding machine.

To these ends and also to improve generally upon machines of this character, the invention consists in the various matters hereinafter described and claimed. In its broader aspects, the invention is notnecessarily limited to the specific constructions selected for illustrative purposes in the accompanying drawing in which I Fig. 1 is a front view, the grinding wheel being removed and the work supply chutes being in 7 section.

Fig. 2 is a right hand side view of Fig. 1.

Fig. 3 is a plan view, the chutes being omitted. Fig. 4 is a plan view of a modification.

Fig. 5 is a front view of parts appearing in Fig. 4.

Fig. 6 is a right hand side view of Fig. 5.

Fig. 7 is a plan view of another modification.

The numeral id indicates a support having a dovetail slideway ii for a slide It which is reciprocated by any suitable mechanism between stopsit and I8 which are preferably thumb screws adjustably mounted in lugs on the support ill. The slide it has an upright portion provided with a pair of work receiving notches or pockets 2t and 2'2, each pocket having bevelled entrance portions 2%, a substantially vertical pushing surface, and a work supporting rest'or blade 26 which is inclined downwardly away from a grinding wheel 28 and towards aregulating wheel 30. Each blade 26 also has a small longitudinal inclination such that a tapered roller R or similar non-cylindrical work-piece will be supported with its axis horizontal or in a plane parallel to the slideway it. Such axisfas will later appear, is not quite parallel to the direction of movement of the slide.

,- surfaces 32 and 34 which are inclined in opposite directions with respect to the active surface of the grinding wheel so that the permanently adjacent surfaces of the wheels form a pair of tapering throats open in opposite directions, the degree of taper depending on the work and being equal to the included angle of the tapered roller R so that the roller will always have that element which is nearest to thegrinding wheel parallel to the active element of the l grinding wheel. Accordingly, when the bottom roller from a supply chute 36 drops into the pocket 20 and is subsequently'carried to the right by the slide M, the roller will also be given a lateral, cross feed movement towards the. grinding surface as such roller rides endwlse along the inclined surface 32. All portions in the length of the roller thus meet the grinding wheel with equal cross feed movement. The crosswise inclination of the blade 25 urges the roller against 33 the regulating wheel surface 32 which controls rotation of the work before and after it meets the grinding wheel.

When the roller R in the pocket 28 has been ground to size, which may be controlled by the adjustable stop It, a left hand stroke of the slide will carry the ground roller past the rollers in the supply chute 36 and into line with an ejector or discharging member 38 which is preferably slidable crosswise of the slide it. The ejector pushes the finished roller out of the pocket 20 into an exit chute till. It will be understood that rollers stacked in a second chute d2 will feed into the second pocket 22 and be ground when the slide moves to the left and that each such finished roller R2 will be pushed by a second ejector or discharge member it into a second exit chute it when the slide completes the next stroke to the right. The upper surface of the slide it acts as a barrier to hold the work in the supply chutes except when an empty pocket arrives under a chute.

It will be noted from Fig. 1 that the tapered rollers in the chute 3% have their larger ends at the left while the rollers in the chutedZ have their larger ends at the right. The work pushing surfaces at the ends of the pockets 20 and 22 are flat and in vertical planes slightly inclined crosswise of the slide to engage the large ends of the respective rollers. Hence these surfaces aid the surfaces 32 and 34 and the blades 26 in locating the rollers as the rollers are shifted towards grinding position. Both blades incline crosswise in the same direction but their lon tudinal inclinations are opposite. One chute, 55

one ejector, one work pocket and one of the surfaces 32 and 34 may of course be omitted.

The grinding wheel is preferably cylindrical and the regulating wheel preferably has its surfaces 32 and 34 conical but these shapes are not essential. The co-operating and permanently adjacent wheel surfaces define a grinding throat which is divergent; or tapering, the relative inclination of the two surfaces being equal to the included angle of the taper roller. The longitudinal inclination of the blade is half of the included angle to support the axis of the piecein a horizontal plane and is equal to the crosswise inclination of the vertical pushing surface of the pocket with respect to the wheel surfaces, the end faces of the roller being normal to the roller axis. The terms horizontal, vertical" and inclined are relative and are used for convenience in definition, it being obvious, for instance, that the slideway 12 need not be horizontal and that the entire apparatus could be tipped in a selected direction.

Figs. 4, 5 and 6 indicate a mechanism for grinding another kind of tapered roller C which is convex or rounded lengthwise. The grinding wheel comprises a concave surface 50 to'conform to the surface of the roller, the wheel also preferably having a tapered surface 32 leading to the surface 50 and an extended portion 54. The regulating wheel has a concave surface 56 conforming to the work surface and an extended portion 51. A slide 58 is provided with a. pocket 60 for the rollers, the bottom of the pocket forming a work rest on blade conforming to the work surface and having a crosswise inclination downwardly towards the regulating wheel. The blade curvative and longitudinal inclination are such as to support the roller with its axis in a horizontal plane. The rollers are supplied to the pocket from a supply chute 62 in which the stacked rollers are normally held back by the angled top surface of the slide. The vertical end of the pocket pushes the roller into the divergent throat formed by the adjacent wheel surfaces 50 and 55.

To prevent the rollers from dropping down beyond the end of the regulating wheel, a guide bar 84 is arranged along the upper edge of the slide and extends close to the wheel surface 56. The roller tends to roll towards the guide bar 64 and the regulating wheel as the slide advances the roller between the wheels. Thus, rotation is imparted to the roller before the grinding wheel begins to grind. The finished roller is ejected when it is retracted to the left of the chute by the slide. If desired, the axis of the regulating wheel 58 may be slightly inclined in a vertical plane and in a direction to urge the roller backwardly against the locating face provided by the vertical wall of the pocket 60.

In ,Fig. 7, apparatus for grinding concavely rounded rollers 68 is indicated. The apparatus is similar to that of Fig. 4' but the grinding wheel tom. or blade are convex to conform to the rollers. Two-way grinding of the rounded rollers of Fig. 4 or Fig. '7 may be obtained by duplicating the curved surfaces of they wheels to provide a pair of oppositely diverging grinding throats, and suplying a second pocket and a second chute as suggested by Fig. 1.

I claim:

1. In a centerless grinding machine, a grinding wheel,. a regulating wheel, the adjacent surfaces of the wheels being relatively inclined mouse to form a tapering throat, a shiftable work blade adapted to enter between the wheels and having its work engaging surface inclined both lengthwise and crosswise to cause a conical work-piece to be located gravitationally bythe blade and the regulating wheel with an element of the conical work surface parallel to the active surface of the grinding wheel, and a slide for shifting the blade into the throat to carry the workpiece endwise along the regulating wheel and thereby feed the piece laterally against the grinding wheel; substantially as described.

2. In a centerless grinding machine, a grinding wheel, a regulating wheel, the wheels having permanently adjacent surfaces relatively inclined to define a tapering throat, a work carrying slide mounted to reciprocate with respect to the wheels substantially parallel to the active portion of the grinding surface, the slide having a work blade inclined lengthwise and peripherally supporting a tapered work-piece, and the slide also having a pushing surface fitting against one end of the work-piece and inclined crosswise with respect to the active surface of the grinding wheel; substantially as described.

3. In a centerless grinding machine, a grinding wheel,a regulating wheel, thewheels having permanently adjacent surfaces relatively inclined to define a tapering throat, a work carrying slide mounted to reciprocate with respect to the wheels substantially parallel to the active portion of the grinding surface, a work blade carried by and shiftable with the slide, the blade having a lengthwise inclination corresponding to the taper of a work-piece, and such inclination being half the relative inclination of the wheel surfaces; substantially as described.

4. In a centerless grinding machine, a grinding wheel, a regulating wheel, the wheels having permanently adjacent surfaces relatively inclined to define a tapering throat, a work carrying slide mounted to reciprocate with respect to the wheels substantially parallel to the active portion of the grinding surface, a work blade carried by and shiftable with the slide, the blade having a lengthwise inclination corresponding to the taper of a tapered work-piece, such inclination being half the relative inclination of the wheel surfaces, and the slide having a pushing surface at one end of the blade and inclined crosswise with respect to the active surface of the grinding wheel, said inclination being the same as said lengthwise inclination; substantially as described.

5. In a centerless grinding machine, a grinding wheel, a regulating wheel, the wheels having permanently adjacent surfaces relatively inclined to define a tapering throat, a work carrying slide mounted to reciprocate with respect to the wheels, a work blade carried by and shiftable 'w-ith the slide, and a pushing surface at one end of the blade; substantially as described- 10, the regulating wheel 12 and the pocket bot- 6. In a centerless grinding machine, a grinding wheel, a regulating wheel, the wheels having permanently adjacent surfaces relatively inclined to define a tapering throat, a work carrying slide mounted to reciprocate with respect to the wheels, a work blade carried by and shiftable with the slide, a pushing surface at one end of the blade, a work supply chute having an outlet adjacent to one end of the throat, and the slide having a barrier shiftable across said outlet; substantially as described.

7. In a centerless grinding machine, a grindthe other wheel a pair of tapering throats open in opposite directions, and means for thrusting a tapered work-piece into one throat while dis charging another work-piece from the other throat; substantially as described.

8. In a centerless grinding machine, a grind ing wheel, a regulating wheel, one of the wheels having oppositely inclined surfaces to form with the otherwheel a pair of tapering throats open in opposite directions, a work supporting blade arranged to enter each throat, and a slide carrying the blades and reciprocable between the wheels to simultaneously carry a tapered workpiece into one throat and remove another workpiece from the other throat; substantially as described.

9. In a centerless grinding machine, a grinding wheel, a regulating wheel, one of the wheels having oppositely inclined surfaces to form with the other wheel a pair of tapering throats open in opposite directions, a slide reciprocating between the wheels and having a pair of work supporting blades; means for supplying tapered work-pieces alternately to the blades, and means for removing the ground work-pieces from the blades; substantially as described.

10. In a centerless grinding machine, a grinding wheel, a regulating wheel, one of the wheels having oppositely inclined surfaces to form with the other wheel a pair of tapering throats open in opposite directions, a pair of work supply chutes having their outlets adjacent to the open ends of said throats, and a slide having work blades inclined lengthwise in opposite directions and reciprocating between the wheels to carry tapered'work pieces alternately into said throats from said chutes; substantially as described.

11. In a centerless grinding machine, a grinding wheel, a regulating wheel, one of the wheels having oppositely inclined surfaces to form with the other wheel a pair of tapering throats open in opposite directions, a pair of work supply chutes having their outlets adjacent to the open ends of said throats, a slide reciprocating between the wheels and havingv a pair of work supporting blades movable alternately into the grinding throats, and a pair of work discharging members outside 0! said chutes and alternately movable crosswise of the blades; substantially as described.

12. In a centerless grinding machine, a grinding wheel, a regulating .wheel, a pair of work supvporting blades adapted to enter alternately the space between the wheels, means for" supplying work pieces alternately to the blades, and a reciprocating slide supporting the blades; substantially as described. p 13. In a centerless grinding machine, a grinding wheel, a regulating wheel, the adjacent surfaces of the wheels being similarly curved and divergent to receive a curved work piece from one side, a work supporting blade curved to fit the periphery of the work-piece, and a reciprocating slide for shifting the blade and workpiece into and out of the divergent space between the wheels; substantially as described.

14. In a centerless grindingmachine, a grinding wheel, a regulating wheel, the adjacent surfaces of the wheels being divergent to receive a tapered work piece from one side, a work supporting blade to engage the periphery of the work-piece, the blade sloping downwardly towards the regulating wheel,'a guide bar leading to the surface of the regulating wheel, and a slide for reciprocating the blade; substantially as de scribed.

15. Ina centerless grinding machine, a grinding wheel, a regulating wheel, the adjacent surfaces of the wheels being concave anddivergent, a work supporting blade having a concave surface with a curvature similar to that of the whee1s,,and a slide supporting the blade and shiftable to carry the blade and a supported work-piece into the space between the wheels; substantially as described.

16. In a centerless grinding machine, a grinding wheel, a regulating wheel, the adjacent surfaces of the wheels being convex and divergent, a work supporting blade having a curvature similar to that of the wheels, and a slide reciprocating between the wheels and carrying the blade; substantially as described.

RAYMOND .H. CRAMER.

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