US556364A - mcgrath - Google Patents

Description

(No Model.)

P. O. MOGRATH. BALL GRINDING MACHINE.

Patented 17,1896.

UNITED STATES PATENT OFFICE.

PATRICK C. MCGRATH, OF'RUTLANI), VERMONT, ASSIGNOR OF ONEJIALF TO I-IARTIVELL A. DALRYMILE, OF SAME PLACE.

BALL-GRINDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 556,364, dated March 1'7, 1896.

Application filed May 1, 1895. Serial No. 547,786- (No model.)

To all whom it may concern.-

Be it known that I, PATRICK O. MOGRATH, a citizen of the United States, residing at Rutland, in the county of Rutland and State of Vermont, have invented a certain new and useful Improvement in Ball-Grindin g Machines, of which the following is a full, clear, and exact description.

This invention has for its object the production of a simple and easily-operated machine for grinding balls for ball-bearings, casters, and other objects, and for grinding or truing spherical bodies generally.

In the machine selected herein in illustration of the principle of my invention I employ a ball-holder, composed of oppositely rotating disks or plates, in conjunction with subjacent rotary grinders of peculiar c011- struction, and these several main elements of my machine are provided with appropriate means for adjusting them in position and relatively to one another to meet the exigencies of the insertion, grinding and removal of the spheres, all as Iwill proceed now particularly to describe and finally claim.

In the accompanying drawings, illustrating my invention, in the several figures of which like parts are similarly designated, Figure 1 is a vertical sectional elevation, Fig. 2 is a side elevation, Fig. 3 is a top plan view, and Fig. 4 is a cross-section, of a modified form of grinder.

a is a bed-plate upon which is mounted the goose-neck stands 1), these latter being connected by a cross-bar or yoke c, which receives the boxes for the various shafts hereinafter described. The middle shaft or spindle cl is stepped in a foot-step or box d containing the antifriction-blocks d and its upper end is borne in a box 61 on the yoke 0, above which it is provided with the drivingpulley d e is a collar fixed to the spindle d by screws e or otherwise.

f is a disk having its periphery beveled and also having a hub f by which it is mounted upon the spindle d, it being supported upon the collar 6 with interposed antifriction-washersf This hub has a flange at its lower end,

and the said hub serves as a band-pulley through which the disk may be rotated upon thespindle, the band being shown in section, Fig. 1. The collar is adjustable upon the spindle to secure the proper position of the disk f.

g is a disk mounted upon the spindle above 7 disk f and having the flanged periphery g, the inner face of the rim of which is beveled complementally to the beveled periphery of the disk f to form a trough for the reception of the spheres tobe ground.

The disk 9 has a lug g which engages a spline or feather g on the spindle, so as to cause the disk to turn with said spindle and also permit of the movement of the disk up and down upon the spindle and so from and toward the disk f.

The disk 9 is provided with two or more set-screws or other adjusting devices 9 abutting against disk fto raise and lower the said disk, in order, respectively, to separate the disks so as to discharge the ground balls and to close the disks upon the balls with sufficient closeness to allow the weight of the upper disk to rest on the balls and confine the balls between the disks, and yet permit free dom of rotation of the balls within the trough while being ground.

In order to adapt the machine to a variety of sizes of balls, I may add a plate h on its inner side, having an annular flange h arranged over the trough to bear upon the balls and hold them down and in such manner that should there be any unusual projections on the balls the said flange will give and thereby relieve the disks of liability to damage. The upper disk is provided with a slot 9 Fig. 3, to provide for the insertion of the balls between the disks. Good results will be obtained by driving these disks in opposite directions at a slow rate of speed, say disk f at about the rate of twenty revolutions a minute and disk g at about the rate of twelve revolutions a minute, and the action of these oppositelyrevolving disks upon the balls is to turn them over and over upon themselves quite rapidly, thereby to bring all of their parts in contact with the grinders. For convenience I have hereinbefore referred to these disks and will again hereinafter refer to them as a holder. I have shown herein two forms of grinders. As seen in Figs. 1, 2 and 3, the grinders are most economically employed in pairs. Each of these grinders comprises a cup-shaped chuck 2', having a hub 11, by which it is readily mounted upon the spindle j to turn with said spindle. The rim 0? of the chuck is provided with longitudinal slits t and with a beveled portion t, which beveled portion is screw-threaded and receives a screw-threaded ring k, having means, such as holes to receive a wrench or spanner, whereby the said ring may be turned up or down to compress the slitted rim of the chuck or to allow the same to expand relatively to the object contained within the chuck. The grinding device proper may be an annulus or disk Z or any suitable grinding material or composition, and it is arranged within the chuck'and confined therein against displacement by the compression of the rim of the chuck thereabout by means of the ring k. The edge of the grinding device is presented adjacent to the trough in the holder which contains the balls. In order to provide for the adjustment of the grinding device as its surface is worn away by use, I support the said grinding device within the chuck upon set-screws m. The spindle j is stepped in abox n on abracket n, projecting from the stand b, and I prefer to employ antifriction-disks or other devices a for the foot-step. The spindle is adjustable vertically in order to bring the grinder in proper proximity to the holder by means of a hand-whcel screw 0 tapped in a threaded (brass) block 02 in the bottom of the bracket n and held in adjustment, as by a set-screw p. The upper end of the spindle j is provided with a box q applied to the yoke c, and above this yoke the said spindle is provided with a band-pulley '1'. By this construction of grinder it is obvious that the grinding device may be very economically used up.

I prefer to rotate the grinding devices in opposite directions to one another, or to 1'0- tate both of them in the same direction, but in a direction opposite to that in which the disk 1" or disk g is rotated.

Instead of the grinding device described I may employ that shown in Fig. 4:, which consists of a disk or wheel or other shaped device s, of grinding material, provided with a metallic hub s, whichmay be mounted upon the spindle in any appropriate manner. The hub 8 may support the grinding device .9, and such grinding device may be clamped thereto by means of a top plate 5 and screws 8 The grinding device may be of stone or emery or other suitable material.

One of the pairs of grinding devices may be of coarse material and the other of fine material, to be used successively, or both may be of the samematerial, in accordance with the work to be done. Obviously, if one grinding device be of coarse material and the other of fine material the same machine may not only do the rough work, but may also be used for finishing, thus economizing in the number of machines to be used in a shop.

I have shown and described my invention as having the shafts arranged vertically; but I do not wish to limit my invention to that arrangement, since it is obvious that for some purposes the shafts may be arranged other than vertically.

I have described the discharge of the balls from the holder as being effected by raising the upper disk by means of the set-screws; but other obvious expedients may be similarly employed and the balls may be otherwise discharged.

What I claim is- 1. A ball-grinding machine, comprising a holder composed of disks mounted upon a spindle common to both and adapted to re ceive the balls to be ground between them and to present them to the grinding device, one of the disks rotating with the spindle and the other being rotated thereupon and in an op posite direction and the two disks being rotated at different speeds, substantially as and for the purpose described.

2. A ball-grinding machine, comprising a holder composed of disks mounted upon a spindle common to both, a flanged plate interposed between them,the said disks and flan ged plate being adapted to receive the balls to be ground between them and to present them to the grinding device, one of the disks rotating with the spindle, and the other being rotated thereupon and in an opposite direction, and the two disks being rotated at different speeds, substantially as and for the purpose described.

3. A ball-grinding machine, comprising a holder composed of disks mounted upon a spindle common to both, set-screws applied to the upper disk and abutting against the lower disk, a flanged plate arranged between the said disks, the said disks having their outer edges constructed to form a trough wherein in connection with the said flanged plate, the balls to be ground are placed, and by which they are presented to the grinding device, one of the disks rotating with the spindle, and the other being rotated thereupon and in an opposite direction andthe two disks being rotated at difierent speeds, sub stantially as and for the purpose described.

at. In a ball-grinding machine, aholdercomposed of two rotary disks, one having its pcriphery beveled, and the other having its periphery flanged, and the inner face of such flange next to the peripheryof the first-named disk complementally beveled to form a trough for the reception of the balls to be ground, the said disks being movable relatively to one another to discharge the ground balls,

and a spindle upon which one of the disks is rotated and with which the. other rotates, combined with set-screws applied to the upper disk and abutting against the lower disk, substantially as and for the purpose described.

5. In a ball-grinding machine, the combination of two or more emery-wheels of the same or different fineness, shafts, and means to drive them independently, upon which shafts the emery-wheels are mounted and by which they are rotated in opposite directions, and a holder carrying the balls at a line tangent to the circumference of the emery-wheels, and means to rotate the said holder, whereby the balls themselves are rotated upon changeable axes and are ground, substantially as described.

6. In a ball-grinding machine, a grinding device mounted upon a spindle, in combination with a stand in which one end of the spindle is boxed so as to be capable of longitudinal movement, a bracket extending from said stand in which the lower end of the shaft is stepped, a threaded block applied to said bracket, a set-screw for holding said block in place and an adj usting-screw connected with said block and operating against the lower 20 end of the spindle in the direction of its length PATRICK O. MoGRATH. VVit-nesses:

M. J. FRANCISCO, D. FRANCISCO.

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