US1862882A - Grinding machinery - Google Patents

Description

June 14, 1932. J. E. cAsTER GMNDING MACHINERY s sheets-sheet 1 Filed sept. 2s. 192e GRlNl/vo JNDEXER-MUY/NG BACK *BACK-E AL L 6 June 14, 1932. J. E. cAsTER GRINDING MACHINERY Filed Sept. 23. 1926 5 Sheets-Sheet 2 anoz "eq J. E. cAsTER 1,862,882

GRIHDING MACHINERY Filed Sept. 23. 1926 3 Sheets-Sheet 3 UNITED STATES I AUI IIIIIUI PATENT OFFICE JOHN E. CASTER, OF CINCINNATI, OHIO, ASSIGNOR TO THE CINCINNATI GRINDERS, INCORPORATED, OF CINCINNATI, OHIO, A CORPORATION OF OHIO GRINDING MACHINERY Application led September 23, 1926. Serial No. 137,205.

This invention relates to improvements in grinding machinery and has particular reterence to a novel and improved mechanism especially designed for use in the grinding of spherical articles such as balls for ball bearings.

Prior to the present invention it has been customary to produce balls by a lapping type of mechanism in which the balls Were fed for example between a pair of high speed members intended to jointly eii'ect slight abrasion of the several surface portions of the ball, coupled with a high spinning action tending to produce the spherical form thereof. This apparatus in commercial use has been elaborate ot structure and slow in operation.

As distinguished from such mechanisms ot the prior art. it is the purpose ot the present invention to provide a novel and improved structure for rapidly producing spherical articles b v a true grinding process, capable of receiving rough forged or molded balls for example and by maximum grinding and stock removal in minimum time to' reduce these rough globules to true spherical form of desired accuracy Within limits of less than a thousandth part of an inch.

A further object ot the invention is the provision of a mechanism for the grinding of balls which Will positively and definitely regulate and control the rotative action of the blanks during grinding.

A further object of the invention is the provision of a mechanism which Will overcome diiiiculties due to dependence on a single grinding surface tor reducingr the initial stock the prescribed amount and which will consecutively present a plurality of formed surfaces to the blank to gradually reduce same to its final accurate dimensions, thus prolonging the lift of the grinding surface as a Whole.

Another object of the invention is the provision of a mechanism Which shall balance and distribute the Wear on the several portions of a formed grinding Wheel to aid in the maintenance of the proper operative surface thereon.

An additional object of the present invention is the provision of a grinding machine in which the progress of the work through the machine shall be ositively controlled and the Work itselt` detpinitely supported in predetermined position Within the machine at all times during operation thereon.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification taken in connection with the accompanying drawings and it will be understood that any modiications may be made in the specific structural details here illustrated Within the scope of the appended claims Without departing from or exceeding the spirit of the invention.

Figure 1 is an elevation of a machine embodying the invention.

Figure 2 is a vertical section through the Work controlling mechanism taken on line 2 2 of Figure 1.

Figure 3 is a diagrammatic view of the movement of the work controlling member.

Figure 4 is a fragmentary view similar to Figure 2, illustrating the shifting member in raised position.

Figure 5 is a detail of the cam and drive mechanism with cover plate removed.

Figure 6 is a sectional View on the line 6-6 of Figure 5, parts being shown in elevation.

Figure 7 is a vertical sectional vieW on the line 7--7 of Figure 2.

Figure 8 is a fragmentary transverse section on the line 8-8 of Figure 2.

Figure 9 is a detail of the Work delivery chute, and,

Figure 10 is a fragmentary view illustrating the regulating Wheel oscillating mechanism.

In carrying out the present invention as illustrated in the drawings, use has been made of a commercial type centerless grinder including'fa bed or base A having mounted thereon a grinding wheel B and a slide C. The in and out position of slide C is controlled through screw D and associate mechanism hereinafter described. Transverscly movable on slide C is a second slide E which bears the angularly adjustable regulating wheel F. Transverse sliding movement may be imparted to the regulating wheel as by forming its spindle 15 with an extension bearing cam 16 in engagement with roller 1T on bracket- 18 of slide C. As a result it will be understood that as the regulating wheel F is rotated the interengagement of cam and roller will cause a transverse reciprocating movement of the wheel for a purpose to be hereinafter described.

Suitably supported on the "bed A is the work rest bracket 19 having at its upper edge the angle top work rest blade 20. This blade as shown in Figure 8 has a corrugated edge providing the work rest portions 21 which lit into the several grooves 22 annularly disposed on the periphery of grinding wheel B.

In the operation of the machine work pieces are fed downward through tube 23 against the work stop 2l carried by the bracket 19 and thence introduced into the first of the series of grooves 22. When so introduced the work piece 25 lies on top of the work rest blade 2O and projects to a greater or less degree into the adjacent groove 22 of the grinding wheel,

while it is backed up on the opposite side by the regulating wheel F. The wheel B is rotated downwardly toward the rest at a high grinding rate of speed. while the wheel F is slowly rotated upwardly and serves to grip and rotate the work. In this connection the oscillation of the regulating wheel is of particular value. If the regulating Wheel had its axis parallel with that of the grinding wheel the combined action of the grinding and regulating wheels would tend to rotate the ball being operated upon but without a universal spinning movement. Also, if the regulating wheel were merely thrown to a slight angle as is most clearly indicated in Figure 10 for example, there would then be a combined thrust component exerted by the regulating wheel..l tending to rot-ate the ball about a horizontal axis and also exerting a diagonal component tending to twist the ball around. This combined action it has been found will produce satisfactory ball grinding in that the combined thrust component being really that of a spiral insures a constant presentation of fresh points on the ball periphery to the operative portion of the groove of the grinding wheel with the result that a perfectly round ball may be produced. It has, however, the objection that the thrust due to angle is constantly in one direction or against the rear side of the grooves, tending to break down the grooves in the grinding i a wheel. It will be understood that the efficient operation of the machine may be continued r only so long as the grinding wheel grooves retain approximately their proper shape. T o counter-act this uni-lateral breaking down of the grinding wheel the reciprocation of the regulating wheel is contemplated. This causes the lateral thrust component of the regulating wheel to be exerted first toward one side of the grinding wheel groove and then toward the other, thus more evenly distributing the wear and prolonging the operative life of the individual grooves.

In order that the maximum production may be secured from the machine, it is desirable to utilize as wide a grinding wheel as possible, thus providing a. number of grooves for simultaneous action on diderent balls. To enable the balls to be inserted within and removed from the grooves, utilization is made of the principle of varying the width of grinding throat as determined by the grinding and regulating wheels. The mechanism for this includes the link 26 coupled with screw D and the cam 27 driven through worm 28 and motor 29, the timing of the parts being such that the cam gradually shifts the regulating wheel in toward the grinding wheel to first close up the throat on the work, then place work against grinding wheel until desired amount of stock has been removed after which throat is then opened up to disengage the work.

In view of the fact that the work pieces as taken to the machine are frequently quite irregular in form, if the entire grinding operation is performed on the rough blank by a single groove there is a great tendency towards slightly breaking down the surface of the groove, thus causing a variation in size of the finished work. To overcome this difliculty the machine is constructed to automatically advance the work pieces from groove to groove, the first groove taking the heaviest cut and the last the lightest, so that in this way a single truing of the grooved wheel will serve to produce a. maximum number of accurately sized work pieces. To cause the step by step movement of the work pieces along the work rest and at the same time to discharge the completed work nieces and introduce new work pieces at the entrance end of the machine, use is made of a carrier member 30 having a. plurality of notches 31 corresponding in number to the grooves on the grinding wheel. This member has depending arms 32 engaged by guides 33 and 34 which permit of its consecutive cycle shifting in vertical and horizontal directions as diagrammatically indicated in Figure 3. These movements are eifected by the double cam 35-36 on cam shaft 37, driven as by chain 38 and pulley 39 from shaft 40. This shaft is driven through spur gearing 41 and bevel gears 42-43 from shaft 44 of cam 27. The movement of the carrier is thus tied in with the canrcontrolled in and out movement of the regulating wheel, so that it shifts at predetermined variations in the width of grinding throat, taking its initial movement which may be considered a vertical movement downward into engagement with the series of rolls on the work rest and with the front terminal roll which is resting against stop 24. This takes place as the regulating wheel is moving outwardly to open up the grinding throat. The next movement is a transverse sliding moving in which the balls or work pieces are all shifted the amount of width of one groove and separating wall rearwardly along the work rest. At this point there is a pause for the shifting plate to steady the balls until the regulating wheel moves in sufficiently to pass them back into their respective grooves. The parts are then in the position illustrated in Figure 2. From this position continued rotation of the cam 35 causes it to engage pin 41 lifting the carrier slide upward out of engagement with the work pieces as is shown in Figure 4. The regulating wheel has then pressed the balls firmly into the grooves of the grinding wheel for operation thereby. As the grinding continues the carrier slide moves back to the' left in position to be brought downward and again engage and shift the series of balls. As shifted the final completed ball is carried away by discharge trough such as 45.

It will be understood that the lateral shifting movement is imparted by the interengagement of cam 36 with the two members 33 as should be clear by reference to Figure 2 of the drawings. It will also be understood that a specifically different mechanism may be utilized for imparting the transverse movement to the balls if desired to use the step by step reduction with a single wheel or that the mechanism may be utilized for single simultaneous grinding of a multiplicity of balls` depending on each groove for finishing its individual ball if preferred. In either event, however, the relative transverse movement to cause a diagonal or lateral thrust against first one side of the grinding wheel groove and then the other is particularly desirable and efficient. It is also to be understood that while the manner of obtaining this diagonal thrust has been shown as that of imparting transverse reciprocating movement to the regulating wheel during the grinding operation, that it is possible to obtain a similar result by reciprocating either the grinding wheel or the work rest on which the balls are frictionally held by the pressure of the grinding wheel and that broadly speaking I consider these three as mechanical equivalent structures in that similar results may be obtained by them, although for simplicity of operation in connection with the shifting carrier and other parts I have found reciprocation of the regulating wheel the more desirable.

I claim l. A grinding machine including opposed grinding and regulating wheels and an intermediate work rest, the grinding wheel moving in the direction of the work rest at a high or grinding rate of speed and the regulating wheel having its operative surface moving upwardly adjacent the work rest at a speed to frictionally engage and control the rate of rotation of the work piece, the grinding wheel having a work receiving groove formed annularly in its face and means for reciprocating one of the three work throat forming members to alternately urge the work piece against opposite sides of the grinding wheel groove to equalize the wear on the walls of the groove.

2. A grinding machine including opposed grinding and regulating wheels and an intermediate work rest, the grinding wheel having its operative surface moving toward the Work rest at a high rate of speed and the regulating wheel having its operative surface moving upwardly as respects the work rest at a slow or regulating rate of speed and means for causing one of the first named parts to exert a lateral thrust component on the work piece, producing a twisting movement of the work piece on the Work support, the grinding wheel having work piece engaging grooves preventing lateral displacement of the work pieces under the influence of said thrust component.

3. A grinding machine including opposed grinding and regulating wheels forming a work receiving throat therebetween, the grinding wheel having grooves in its face complementary to those to be produced on a work piece, means for alternately opening and closing the work receiving throat, and means for automatically advancing the work piece in a step by step movement as the throat is alternately opened and closed.

4. A grinding machine including a grinding wheel having a grooved peripheral face, means opposed to the grinding wheel for engaging the work and imparting a twisting movement thereto as respects the grooved face of the grinding wheel and means for supporting the work piece in the throat between the grinding and regulating wheels, said work supporting means being disposed in position to take up the thrust of the rotating grinding wheel whereby the combined effect of the grinding wheel grooves and work rest limit the bodily displacement of the work tended to be imparted thereto by the grinding wheel and its opposed member.

5. A centerless grinding machine including a work rest, a grinding wheel disposed at one side of the work rest and operable at a high grinding rate of speed with its adjaummm( cent surface moving in the direction of the work rest to urge work pieces thereagainst, a regulating wheel disposed on the opposite side ofthe work rest with its operative surface moving upward relative thereto and rotatable at a slow rate of speed to control the rate of rotation of the work, means providingr definite stations for the individual work pieces during grinding, and means for positively shifting the work from station to station.

6. A centerless grinding machine of the character described including a grinding wheel operable at a high grinding rate of speed and an opposed regulating wheel operable at a slow controlling rate of speed to control the peripheral presentation of the work to the grinding wheel, a. work rest disposed intermediate said parts for supporting work for the combined grinding and controlling actions of said wheels thereon, and autO- matic means for positively imparting predetermined increments of movement longitudinally of the work rest to work pieces wherebv the work nieces are intermittently shifted from entrance to discharge termini of the grinding throat between the said wheels.

7. A centerless grinding machine of the cha acter described including a grinding wheel operable at a high grinding rate 0f speed and an opposed regulating wheel operable at a slow controlling rate of speed, a work rest disposed intermediate said parts for supporting work for the combined grinding and controlling actions of said wheels thereon, an automatic means for positively imparting predetermined increments 0f movement longitudinally of the work rest to work pieces whereby the work pieces are intermittently shifted from entrance to discharge termini of the grinding throat between the said wheels, said means having portions for holding individual work pieces in predetermined spaced relation during said shifting movement.

8. A centerless grinding machine for the production of contoured articles including a grinding wheel operable at a high rate of `speed having a contoured surface adapted for simultaneous engagement with a plurality of work pieces, a work rest for supporting said work pieces and an opposed slowly operable regulating wheel for controlling the rate of rotation of the work pieces, and intermittently operable means engageable with the work pieces for transferring the work pieces in predetermined spaced relation from one to another of the contoured work engaging portions of the grinding wheel.

9. A centerless grinding machine for the production of contoured articles including a grinding wheel operable at a high rate of speed having a contoured surface adapted for simultaneous engagement with a plurality of work pieces, a work rest for supporting said work pieces and an opposed slowly ops erable regulating wheel for controlling the;

rate of rotation of the work pieces, intermittently operable means engageable with the work pieces for transferring the work pieces in predetermined spaced relation from one to another of the contoured work engaging portions of the grinding wheel, and means for automatically supplying additional work pieces to the transfer mechanism.

l0. A grinding machine for simultaneous operation on a plurality of contoured work pieces including a grinding wheel having a plurality of distinct contoured work engaging portions, an opposed regulating wheel for controlling the rotation of said work pieces, a work rest intermediate the grinding and regulating wheels in the work engaging throat formed thereby, and a comb member disposed in opposition to the work rest for simultaneous engagement with a plurality of work pieces and means for shifting the comb when in engagement with the work pieces whereby the work pieces may be transferred from one to another of the contoured portions of the grinding wheel in proper spaced relation.

11. A machine for the production of balls 0r other contoured articles including a contoured high speed grinding wheel and an opposed slow speed work controlling wheel forming a grinding throat therebetween, a work support-ing rest projecting within the grinding throat, means for varying the width of grinding throat, and means for shifting individual work pieces transversely of the grinding throat when the same is 0f increased width comprising a work transferring member having portions for engaging and retaining individual work pieces in predetermined spaced relation, and means for laterally shifting the work engaging member while the work pieces are so held.

12. A machine for the production of balls or other contoured articles including a contoured high speed grinding wheel and an 0pposed slow speed work controlling wheel forming a grinding throat therebetween, a work supporting rest projecting within the grinding throat, means for varying the width of grinding throat, and means for shifting individual work pieces transversely of the grinding throat when the same is of increased width comprising a work transferring member having portions for engaging and retaining individual work pieces in predetermined spaced relation, means for laterally shifting the work engaging member while the work pieces are so held` means for disengaging the work shifting member from the work pieces, and for returning same to work re-engaging position.

13. The combination with a centerless grinder including opposed grinding and regulating wheels and an intermediate work JOHN E. CASTER.

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