US1026351A - Method of grinding balls. - Google Patents

Description

A. E. GREENE. METHOD OF GRINDING BALLS.

11 1 110111011 r1121) JULY 20, 1911.

Patented May 14, 1912.

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Patented May 14, 1912.

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METHOD OF GRINDING BALLS.

APPLIOATION nun JULY 20, 1011 1,026,351 Patented May 14, 1912.

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BY I

A TTORNJZ Y3,

AUGUSTINE E. GREENE, OF HARTFORD, CONNECTICUT.

METHOD or GRINDING BALLS.

Original application filed February 20, 1911, Serial No. 609,562.

I Specification of Letters Patent.

Divided and this application filed July 20,

1911. Serial No. 689,656.

To all 1.072 om it may concern Be it known that I, AUGUSTINE E. Gnnnxn, a citizen of the United States of America,residing at Hartford,in the county of Hartford and State of Connecticut, have invented a new and useful Method of Grinding Balls, the same being a divisional part of my ap lication, filed in the United States Patent fiice February 20, 1911, and serially numbered 609,562, of which the following is a specification.

My invention relates to improvements in processes or methods of making balls of various kinds or out of various materials, and consists in imparting a varying conical rotation to a ball while in contact with a revosimilar figures luble grinding or polishing member, the rotation of such ball being around a constant same manner as in the first instance, the mo-.

tion imparted to the ball during the aforesaid grinding or polishing operations being such that the time of contact between the ball and the grinding or polishing member at any given point of contact on the ball is approximately the same as such time of contact at any other given point of contact on the ball, all as hereinafter set forth.

The primary object of my invention is to produce in an economical and expeditious manner balls which are uniform in size, shape and finish, being perfectly spherical, and this without impairing, injuring, or changing the properties or inherent characteristics or qualities of the material from which the balls are made, which material may be of-any suitable character.

Other objects will appear in the course of the following description.

As a means of carrying my invention into effect, so as to be able to attain the objects and secure the advantages of the same, mechanism such as I have herein illustrated may be employed, the method being well exemplified in the operations which said mechanism is capable of producin In the accompanying drawings, in which refer to similar parts throughout the several views, Figure 1 is a top plan of a machine with which my method can be carried out successfully; Fig. 2, an enlarged side elevation of a chuck and associated parts used in said machine, a portion of the drum which carries these members appearing in section; Fig. 3, a similar view to the preceding, as said chuck and associated parts appear from above; Fig. 4, a vertical section taken on lines 4-4, looking in the direction of the associated arrow, in Fig. 2; Fig. 5, a front elevation of said machine; Fig. 6, a diagram illustrative of the action of the ball-holding mechanism and having particular reference to the method; Fig. 7, a right-hand elevation of the machine, and, Fig. 8, a vertical section taken on lines 8-8, looking in the direction of the associated arrow, in Fig. 5.

I will commence by describing the method without relation to the particular or detailed means or mechanism for giving it practical effect and putting it into practical use; after which I will explain such mechanism as is shown in connection herewith.

A ball, in a more or less rough and unsymmetrical condition, is brought under the influence of an attracting or holding elemental force, such as electro-magnetism (as illustated in connection herewith) or socalled suction created by a partial vacuum produced by exhausting air from a container (as set forth in the application of.

which this is a divisional part, also in another divisional application filed on even date with this application), and while in the power or under the dominance of this force said ball is rotated about one axis and coincidentally oscillated upon another axis which is at right-angles to the first, the point of intersection between the two axes being fixed or permanent and with which the true center of the finished ball coin cides.

A finished ball is represented at 1, in Figs. 2, 3 and 6, and the point just mentioned as being that upon which the ball turns in two directions at right-angles to each other, or the point at the intersection of the two axes which are arranged at rightangles to each other, is the exact center of said ball 1. Thus it is clear that the motion of the ball may be described as a spiral, conical rotation of an axis of rotation, in short, as gyratory. \Vhile the ball is thus in motion an abrader, revolved on an axis Patented May 14, 1912.

which if continued would coincide with the principal or main axis of the ball or of the ball-holding and operating mechanism, is

brought into engagement with said ball, and one-half or usually something more than one-half of the superficial area of the ball is ground or polished by said abrader, because of the gyratory motion of the hall, moreover, the ball is abraded in a perfectly symmetrical manner, so that a true hemisphere is produced, which would not be the case if there were no gyratory motion to cause all parts of the surface being abraded to receive the same amount of treatment or dressing from the abrader, because then those portions of such surface that were at and nearest the axial center of the abrader would be subjected to less frictional energy or attrition, since the speed of the abrader is less the nearer its axial center is approached, than those portions-of said surface that were farthest from such center, where the speed of said abrader is greatest. It must be plain, therefore, that by the proper manipulation of the ball while being abraded I am able to equalize the action of the abrader thereon. After thus abrading one-half or a little more of the balls surface, the abrading operation is discontinued, the ball is released from the holding forceand rolled over, so to speak, to present the other or undressed half to the abrading action, said force is reapplied, and the abrading operation reestablished, the same result being produced as before. After this the abrading operation is again discontinued and the ball is a second time released from the attracting or holding force. By this method, which comprises the two abradings and the intermediate rolling, a ball which is a true sphere and therefore perfect is theoretically produced, although in practice the ball needs to be put through the process a number of times, unless or until only a slight polishing eifect is all that is required, in order to obtain the thoroughly finished and absolutely symmetrical product.

The intermediate or rolling step in the process preferably and usually consists in frictionally engaging the ball and by reason of such engagement causing said ball to change its position relative to the material or mechanical holding medium therefor. This may be done either by moving the ball while in contact with the friction surface along such surface, or by moving the latter across'the engaging part of the ball, the

.ball having imparted thereto in either case 'a partial rotation in or relative to the aforevolves and oscillates, represented at the cenv thereof.

4 tral standard 13.

ter of the ball 1, in Fig. 6, but there are also represented therein the principal or main axis, at 2, and, as an example merely, five positions of the axis of rotation, at 3, which will assist in the understanding of the above-described method, or that part of it which involves the gyratory motion of the ball. The axis of rotation is fixed at the ball end, where it may be said to fulcrum, but is or may be flexible or jointed so that the other end can be moved longitudinally on the axis 2, as when actuated by a cam, and the lines 5 indicate such complementary parts in the five positions of such axis; shown. In this way the axis of rotation be- 30 comes an oscillatory axis of rotation.revolv-' ing around the principal or main axis. I will now describe in detail the mechanical meansherewith presented for carrying out the foregoing method, but before doing 35 so wish to state that I do not in any sense limit myself or the carrying out of my method to said means, nor do I desire or intend to limit myself or to be limited to the exact details of the herein described method, since more or less departure, change or modification from or in the prescribed course herein laid down and specified may be made without departing from the natureof my invention or violating the spirit Inasmuch as the machine and its several mechanisms are included in the applications above referred to and are not claimed herein, they will be explained as briefly as may be in order to make clear the manner in which the method can be put to practicaluse.

i A frame is represented at 6. This frame has two head bearings 7 provided with the same number of caps 9 at the right-hand end, fora rotary ball-operating drum 10,, stands 11-11, at the left-hand end, for an. abrader-operating carriage 12, and a cen- J ournaled in'th'e frame 6, below but in the" rear of the vertical plane of the axis of the drum 10, is ashaft l4. Secured to the outer end of the shaft 14: is a driving pulley 15 driven by a belt '16. Secured also to the shaft 14, inside of the pulley 15, is a gear 17 that meshes with a loose gear 18 on a stud l9 projecting from the outer end of the frame head and having its axis in line with the axis of the drum 10. Secured on 12 the inner end of the shaft 14 is a gear 20. J ournaled in the center of the frame, longitudinally, is a shaft 21 which is driven from the shaft 14 through the medium of the gear 20 and a gear 22 secured to said '125 shaft 21. A short-shaft 23 is journaled in the frame head and this shaft has a gear- 24 secured on its outer terminal to mesh with a large gear 25 on the outer end of the drum 10. 1311 -holder 49 is made of soft iron. end of this holder is cupped to fit the balls gear 25, the drum 10 is thus caused to make one-fourth of a revolution.

The abrader-operating mechanism is driven independently by means of a belt 27 and a loose pulley 28 on a stud 29 at the left-hand end of the frame 6. The pulley .28 is'rigidly attached to a large pulley 30 which is also loose on the stud 29, a 1d a belt 31 connects said pulley 30 With the aforesaid abrader-operating mechanism in the manner hereinafter explained, an idler 32 being provided for said belt, which idler is mounted on a stud 33 projecting from the frame above said stud 29.

Suitably journaled in the drum 10 and extending beyond both ends thereof are four spindles 34. These spindles are arranged at equal distances from the longitudinal center of the drum and at equal distances from each other, and have secured on their outer ends pinions 35 which mesh with the constantly revolving gear 17. Each spindle 34 is provided at its inner terminal with a yoke 36, and slidingly mounted on such spindle is a cam-sleeve 37. A spring 38 encircles each spindle 34 between its yoke 36 and a washer 39 which bears against projecting parts of the cam-sleeve 37 on said spindle, and retains said sleeve with its camface against an abutment in the form of a roll 40 which is in the path of said camface. There is a roll 4.0 for each cam-sleeve 37, and such roll is mounted on a stud 41 carried by a supporting bracket 42 that is rigidly attached to the drum in proper relation to the adjacent cam-face. Pivotally attached at 43-43 to each cam-sleeve 47 is a yoke 44, and pivotally attached at 45 to the left-hand terminal of said yoke is a chuck 46. Each chuck 46 has two arms 47, at the end opposite that which is pivoted to the supporting yoke 44 therefor, and these arms are pivoted at 4848 to the free terminals of the associated yoke 36, inside of the arms or branches of the same. Each chuck has, furthermore, a core 49 which projects from the barrel or spool of said chuck between the arms 47 and constitutes the actual holder for the balls. The "ore or The exposed and form a good and suflicient contact or connection therewith.

The roll 40 in each case is so situated that the contacting cam-sleeve 37 can never slide on its spindle 34 far enough toward the drum 10 to allow the axis of the associated chuck 46 to coincide with the axis of said spindle, and. since said chuck swings at one end on an axis, represented by the pivots 48, the angle of inclination of the chuck a'xis changes as the parts revolve with said spindle, because said sleeve is then reciprocated by reason of the contact between its cam-face and said roll and through the medium of the connecting yoke 44. Thus the point of intersection between the spindle axis, which is the principal or main axis corresponding to the line 2 in Fig. 6, and the secondary axis or the axis upon which the chuck oscillates, represented by the pivots 48, because the point about and upon which the revolution and the oscillation of the chuck take place, and is the center of the erfect ball, it being understood that the distance from such point to the center of the holder 49 is equal to one-half the diameter of such ball. The axis of the chuck is represented by the lines 3 and the connecting or longitudinal axis of the yoke 44 by the lines 5, in Fig. 6, in the five different possible positions given them by the cam acting against the roll and moving the adjacent end of said yoke axis along the spindle axis. By this means and in this manner a ball in the holder receives the motions already very fully described.

Inasmuch as electro-magnetism is the active natural agent or medium herein represented as being employed for retaining the balls firmly and securely in the holders 49, I will next explain the means for applying the same. The drum 10 is provided with a commutator 50 for each chu'ck' 46, and a brush 51 is provided for each commutator, such brush depending from an insulating .bracket 52 mounted on the inner cap 9. The bracket 52 is provided with adjusting screws 53 for the brushes 51 and the latter with binding-posts 54, as usual. \Vircs 55 lead from the binding posts 54 to a suitable source of electrical energy, indicated at 56,. Fig. 1, and a wire 57 leads from such source to a non-insulated binding post 58 on the outer cap 9. Each commutator is connected, in the customary manner, by a wire 59 with a binding-post 60 set in aninsulated bracket 61 attached to the drum adjacent to me of the spindles 34, and a short wire 62 connects such binding-post with a brush 63. Each brush 63 is adjustably held in one of the brackets 61 by a screw '64. Secured to each spindle 34, with an insulating ring 65 between, is a contact ring 66 against which one of the brushes 63 bears. A wire 67 leads from each contact ring 66 to a binding-post 68 at the inner end of one of the arms or branches of the yoke 36 which is at the inner terminal of the spindle 34 upon which such ring is mounted, said wire passing from such ring through radial openings in the associated insulating ring 65 and spindle to a central longitudinal passageway 69 in said spindle, as shown in Fig. 4, thence through such passageway to said yoke, out through a suitable openingin the yoke, and along the outside of the yoke arm which supports said binding-post to the' latter, as best shown in Fig. 3, the aforesaid opening in the yoke being represented by dotted lines at 70. A short wire 71 connects the binding-post 68 with a binding-post 72 on the chuck 46in this combination, and the circuit to the frame is completed through a short wire 73 which connects two binding-posts 74 and 75 also on said chuck, but the binding-post 75 being non-insulated. The binding-posts 72 and 74 are the terminals of-the electromagnet which forms part of the chuck 46. Thus the circuit from the source of energy at 56 to any chuck 46 and back to such source is formed by the proper wire 55, brush 51 and commutator 50, and the wires 59 and 62, brush 63, ring 66, and the wires 67, 71 and .73 in the combination, the frame of the machine, and the wire 57.

The arrangement of the commutators '50 and the timing of the drum 10 are such that each chuck 46 or its holder 49 is magnetized and demagnetized four times at every revoluticn of said drum, but all of said holders are not magnetized and demagnetized together. When any holder 49 is magnetized it attracts to itself and holds securely any ball that is a good subject for magnetic attraction when brought into the field of such attraction emanating from such holder, and releases said ball upon being demagnetized;

For the purpose of impartingtlinecessary independent rolling motion or half revolution to the "ball when it passes from one abrader to the other, as yet to be more fully explained, so that theunabraded portion or side will be presented to the second abrader, a piece of felt or other suitable material to form a friction member 76 is attached to the right-hand face of the stand ard 13 near the top.. The friction member 76 occupies a position such that the center of its exposed or working face approximately coincides with the top of the ver tical diameter of the circle described by the left-hand end of the horizontal diameter of a ball held by any one of the chucks 46, but encro-aches somewhat on the vertical plane of such circle. Such being the case, a ball held by one of the chucks 46, if such chuck were energized, would be carried past although frictionally engaging the member 76 without being affected thereby, but if the energy be cut off from such chuck after it has brought said ball into rubbing contact with said friction member,-the latter will impart an independent rolling motion to said ball, or, in other words, will rotate said ball in its holder, the amount of such rotation depending upon the length of the friction 'member and the length of time the chuck remains unenergized. This is exactly what is done in practice, and, since the ball is held so tightly by the friction member in the cupped end of the operating holder 49 that said ball cannot get out of said holder, the ball rolls or is rolled in the holder, and when it has been turned half over or half way around therein the chuck is energized again and carries the ball wit out further independent movement or moti 11 off of and away from said member 76. Although the chuck does not stop rotating while the ball is being carried past the member 76, the motion of the chuck in no wise interferes with the independent rolling of the ball, but rather facilitates such action.

Passin r to the abrader-operating mechanism which includes the carriage 12, it will be observed that such carriage is reciprocated by means of a cam 100 secured on the shaft 21 between the stands 11. This cam has a cam-groove 77 therein to receive an anti-friction roll 78mounted on a stud 7 9 set in the bottom'of the carriage 12. The form or shape of the cam-groove 77 is such that at.,.eve'iy revolution of the cam 100 the carriage, through the medium of the roll 78 and stud 79, 15 caused to travel from one end of its course to the other and back again. The other members of the abrader-operating mechanism consist of two parallel spindles80 arranged to revolve side by side in two pairs of bearings 81 and under two pairs of caps 82 at the opposite ends of the carriage 12, and of the attached and associated elements described below. The spindles 80 do not rest directly in the lefthand bearings 81 and caps 82, but in collars 83-"83 which are tapped into said bearings and caps. The spindles are not only capab of revolving in their bearings, but they may also be reciprocated therein. Said spindles extend beyond the left-hand bearings 81, and the belt 31 passes under the pulley 30, over these extending portions of the spindles, and

under the idler 32, so that the spindles are.

driven in the same direction at a great speed by said belt and rotary members and'by the belt 27 and the pulley 38. These pulleyextensions, as they may be called, shown at 84-84, of the spindles 80, are of sutlicient length to permit of the required amount 01 longitudinal movement without the belt 31 running off. Attached to the inner terminal of each spindle 80 is a head 85 which receives the stem of a suitable holder 86 for an abrader 87, a set-screw 88 being employed in the customary manner to assist in securing said stem to said head and to afford adjustment for said stem. The abraders 87 are made of any suitable grinding or polishing material. A. collar 89 is secured to each of the spindles 80 in position to bear against a .innermost independent positions with a force that may be varied by screwing the collars 83 in or out. The springs 90 are sutliciently strong and stiff to hold the abraders 87 to their work, when the carriage 12 is in its advanced position, yet such springs afford yielding means for the spindles 80 whereby said abraders cannot be forced too hard against the balls, as might otherwise happen occasionally in the event the balls should be too large. As previously intimated, the ball-extensions 84 are long enough to enable the carriage to complete its inward travel without disconnecting the motive power, also, of course, to permit of whatever little independent movement there may be longitudinally on the part of the spindles 80. The base ,of the carriage 12 is flanged at 91 to fit and slide in guide-ways on the stands 11, such guide-ways consisting in part of plates 92. The cam-groove 77 is so shaped that a dwell is produced at each end of the throw of the cam 100, so that, at each revolution of said cam, the carriage 12 is actuated forward and backward and held during parts of such revolution in both of its extreme positions. The abraders 87 are hollowed or recessed in the centers of their working faces to receive the balls, in much.

the same manner as are the holders 49, and when the abrader holders 86 are properly adjusted in the heads 85 and the collars 89 are against the contiguous bearings 81 and caps 82, the cam 100 as it revolves advances the parts, until the centers of the cupped portions of said abradcrs coincide or approximately coincide with the'circular path at the right-hand. ends of the horizontal diameters of the finished balls carried by the chucks 46. In other words, the point of intersection between the oscillatory axis of rotation and the main or principal axis around which such oscillatory axis revolves, of any chuck when juxtaposed to an advanced abrader, that is, of a chuck which is in such position that its main axis it continued would coincide with the axis of said abrader is the same distance fromthe center of the concavity in said abrader as it is from the centerof the concavity of the holder 49 of said chuck.

Although this machine is provided with automatic means for feeding the balls, only a trough or raceway 93 is herein shown, since that is all that is needed for a clear understanding of the subject matter of the present application. The raceway 93 is supported from the floor by a member 94 which is braced from the frame 6, as shown at 95, in Pig. 8. The raceway 93 curves rearwvardly and slantsdownwardly from the member 94, to open at its back end toward the orbit of the holders 49 and at a poliit which is below the advanced position of the forward abrader 87 or of the working face of said abrader. This raceway constitutes part of the almve-menticned ball-feeding means, and is the member that receives the balls an'didelivers them to the ball holders.

'lheoperation of the machine described above, which involves or includes my method, is as follows, said method in the followmg description being set forth in fuller detalls than heretofore. Having connected both ends of the machine with the power, the revolving members are set in motion, rotating in the directions indicated by the arrows associated therewith, andsome of such members revolving constantly and some intermittently, as alreadymade plain, and as about to be further explained. The gear 17 on the shaft 14 with the pulley 15, through the medium of the intermediate gear 18 and the pinions 35, causes the four spindles 34 to revolve constantly; and the gear 20, also on said shaft and through the medium of the gear 22, causes the shaft 21 to revolve constantly with the cam 100 thereon. Coincidentally, the spindles 80 are driven constantly by the belts 31 and 27, but generally in the opposite direction to that of the spindles 84. Assuming, now, thatthere is a ball in the raceway 93 and that balls are being delivered to said raceway, by the time the first ball arrives at the open rear end which is the discharge 01' delivery end of said raceway there is a chuck 46 in position adjacent to such end, with its holder 49 energized, to pick said ball from said raceway and securely hold it, the electric circuit to and through such chuck being closed at this time by reason of the fact that the commutator 50 which belongs in said circuit has one of its electrical contacting segments in contact with its brush 51. Although the spindle 34 with which the aforesaid chuck is connected is revolving the circuit is not interfered with because of the presence of one of the contact rings 66 on such spindle, and the connection afforded by the brush 63 which bears on said rin \Vhile held securely by theenergized chul: 46, which for convenience will be called the first chuck, the ball is carried thereby from the receiving position to the first abrading position in line with the forward abrader 87, which abrader meanwhile is in retracted position. The first chuck with the ball is moved into the new position by reason of the fact that the constantly-revolving shaft 21 imparts to the shaft 23, through the medium of the clutch 26, one-half of a revolution, and said shaft 23 in turn with its gear 24 imparts one-fourth of a revolution to the gear 25 and the drum 10 which carries said chuck; and said chuck with the ball is left in such position because, by the time or at the time it arrives there, said clutch releases said shaft 23 and the movement of said drum ceases. Immediately the cam 100 advances the carriage 12 and thrusts the forward abrader 87 against the ball now held and rotated by the first chuck in the first abrading position, the ball being rotated in the peculiar manner previously set forth at length. One side of the ball is subjected to the action of the forward abrader until the latter is withdrawn, when the clutch operates to give the drum another quarter turn. Meanwhile the second chuck has picked the second ball from the raceway 93 at the receiving position.

Just before the first chuck moves-from the first abrading position adjacent to the forward abrader to the second abrading position adjacent to the rear abrader, the cam 100, which retains the forward abrader in advanced position during the abrading op eration, retracts the carriage 12 and so takes the abraders from the field of action, and said cam keeps them out of such field until the first chuck arrives at the second abrading position, when, of course, the second chuck will be in the first abrading position.

Upon the second quarter of the revolution of the drum 10, the first ball is caused to traverse the friction member 76, and just after said ball reaches said member the first chuck is demagnetized, so as to enable the ball to roll in its holder or to be rolled therein by frictional contact with said member, and just before said ball leaves said member said chuck is magnetized again. The first ball, thus turned half way over or around so as to present the undressed side to the rear abrader, is next left at thesecond abrading position, when for a second time the clutch 26 free the shaft 23, and the abraders are advanced and operate this time on two balls, the rear abrader operating on the first ball attached to the first chuck and the forward'abrader operating on the second ball attached to the second chuck. It is thus seen that one side of each ball is dressed by the forward abrader, and that the other side of each ball is dressed by the rear abrader. For the second time the abraders are retracted, and then the drum makes the third quarter of its revolution, with the result that the first ball is dropped from the now demagnetized chuck, the second ball is carried 'to the second abrading position, be-

ing turned half way around on the way, and the third ball, which the third chuck has already picked, is brought to the first abrading position. With the completion of the revolutlon of the drum, during the last quarter of which the second ball is dropped, the

third ball is carried to the second abrading position and the fourth ball held by the fourth chuck to the first abrading position, and the first chuck is again magnetized so that it can pick the fourth ball, one cycle of the machine is complete, provided such cycle" start with the picking of the first ball by the first chuck, in accordance with the foregoing description. During this cycle the drum operates at four regular intervals, the carriage advances and retreats four times, and each chuck is demagnetized twice, once when it passes the friction member 76, and once again when it drops the ball after the second abrading.

The balls may be run through the machine a number of times or until they are reduced to the exact size desired or are finished or polished to the required degree of nicety. With this machine balls of any material that is subject to magnetic attract-ion can be handled, but the same method can be carried out with the aid of a machine equipped with means for handling balls of other materials.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. A method of abrading spherical objects, consisting inv imparting an orbital gyratory motion to an object on its own center while subjected to an abrading action.

2. A method of abrading spherical objects, consisting in imparting a combined rotary and orbital oscillatory motion to an object,on its own cent-er while subjected to an abrading action.

3. A method of abrading spherical objects, consisting in imparting a varying conical orbital rotation to an object on its own center while subjected to an abrading action.

,4. A method of abrading spherical objects, consisting in applying an elemental force to an object to hold the same, in imparting a combined rotary and orbital oscillatory mot-ion to said object on its own center while thus held, and in subjecting the moving object to an abrading action.

5. A method of abrading spherical ob jects, consisting in applying an elemental force to an object to holdthe same, in imparting a combined rotary and oscillatory motion to said object while-thu held, in subjecting the moving object to an abrading action, in releasing and turning said object independently, in reapplying said force and restoring said combined rotary and oscillatory motion to the object, and in again subjecting the moving object to said abrading jects, consisting in g'yrating an object while subjected to an abrading action, and in interinediately partially turning such object on one of its axes.

8. A method of abrading spherical objects, consisting in gyrating an object While subjected to an abrading action on one portion of its surface, and in partially turning said object to present another portion for such action.

AUGUSTINE E. GREENE. \Vitnesscs A. C. FAIRBANKS, F. A. CUTTER.

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