US1024256A

US1024256A - Work-holder.

Info

Publication number: US1024256A
Application number: US639657A
Authority: US
Inventors: Augustine E Greene
Original assignee: Individual
Current assignee: Individual
Priority date: 1911-02-20
Filing date: 1911-07-20
Publication date: 1912-04-23
Anticipated expiration: 1929-04-23

Description

A. E. GREENE.

WORK- HOLDER. APYLIGATION FILED JULY 20, 1911.

Patented Apr. 23, 1912.

4 SHEETS-SHEET 1.

J Hu -w.

- I JNVENTOR.

ATTORNEY A; E. GREENE. WORK HOLDER.

1 nrmouron FILED JULY 20; 1911.

I Patented Apr-.23, 1912.

LVIVENTOR.

nu-M, BY

4 SHEETS-SHEET 2.

. ATTORNEYJ A. B. GREENE.

WORK HOLDER. Arrnicnmn IvII-ED -TULY20,-1 912 l. 1,024,256,. Patented Apr. 23, I912.

anna-5113MB.

iVJTNESSES; I I 'IIVVENTOR. 1 Q 6*.

A TTORNIIYE.

1 A. E. GREENE.

' WORK HOLDER. nr'mdulon rILnn JULY 20, 1911.

(1,024,25 I Patented Apr. 23, 1912.

4 snnE'rsHmEm: 4.

. ///Y//////////////////////V\' as a7 uz WITNESSES:

A TOR/VEY '1 UNITED strA'rEs PATENT oFFIoE.

AUGUST IKE: E. GREENE, or nnrronn, 'oomvnc'rrcn'r.

WORK-HOLDER.

Specification of Letters Patent.

' Patented Apr. 23, 1912.

Original application filed February 20, 1911, Serial No. 609,562. Divided and this application filed July 20,

1911. Serial no. 639,657.

To all whom it may concern: I

Beit known that I, AUGUSTINE E. GREENE, a citlzen ofthe United States of America,

- residing at Hartford, in the county of Hartdivisional part of an. application filed by me in the United StatesPatent Office February 20, 1911, and serially numbered- 609,562, ofwhich the following is a specification.

My invention relates to improvements. in devices for holding spherical objects while being ground, polished, or otherwise treated or dressed, and especially adapted for ballmaking or -finishingmachines, and resides in certain peculiar mechanical means for utilizing an elemental force to hold and release such objects, as hereinafter set forth.

\Vith' this work holder the member, at the-endof which it is necessary to hold an object so that it can be subjected to the action of an abrading member, has imparted to its axis of rotation a varying conical roaxis about which said first-mentioned axis revolves is. changeable. This is a valuable and important feature for the obvious reason that provision is thus made for abrading the object evenly and uniformly and producing a true sphere.

The object of my invention is, therefore, to provide a coacting andv highly efiicient work holder which is capable of holding an object and imparting a rapid gyratory motion thereto while the same is being ground, polished, or otherwise treated or dressed, and this without impairing, injuring, or changing the properties or inherent characteristics or qualities of the material from which such object. is made, and regardless of the character of the object.

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

I attain these objects by the-mechanism illustrated in the accompanying drawings, in which- Figure 1 is a top plan of so much of a ball-making or finishing machine .as is requisite to show the application of a practical form of my invention; Fig. 2, an enlarged side elevation of one of themagnetic chucks and'associated parts, a portionofthe 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, lookingin the direction of the associated arrow, in Fig. 2; Fig. 5, a front elevation of the part of the machine shown in the first View, Fig. 6,.a

diagram illustrative of the action of the- Work holder; Fig. 7, an enlarged top plan of the clutch which controls the drum; Fig. 8, an enlarged face View of said clutch, looking from the left; Fig. 9, a right-hand ele vation of said machine, without the supporting legs; Fig. 10, a vertical section taken on lines 10-10, looking in the direction of the associated arrow, in Fig. 5; Fig. 11, a front elevation of the machine head equipped with pneumatic work-holding mechanism, instead of electromagnetic work-holding mechanism as in the first in stance; Fig. 12, an. enlarged inner face view of the stationary airor suction-chamber case; Fig. 13, an enlarged face view of the revoluble ring which fits into said case and has the chuck spindles connected therewith, as viewed from the left, one pair of the spindle-holding plates being omitted; Fig. 1 1, an enlarged detail, in partial section,

showing most of the principal parts of the pneumatic head, intermediate portions-of the spindles being broken out, and the sec-' tion through the air-chamber case being taken on lines 14-14, looking in the direction of the associated arrow, in Fig. 12, and,

.Fig. 15, an enlarged fragmentary detail, in

parts of the so-called suction chuck is rotated about one axis and coinci dentally oscillated upon another axis which. is at right-angles to the first, the point of of the finished object coincides.

- object, a ballin "t 115 case, is represented at l, in Figs. 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 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 rota tion of an axis of rotation, in short, as gy: ratory. Because of this gyratory motion imparted to the ball by the work'holder, one-half or something more than one-half of the superficial area of the ball can be presented to a rotary member having an axis which if continued would coincide with the principal or main axis of the ball or of said holder, in such a manner that the ball receives uniform treatment from said rotary member, which would not be the case if there were no gyratory mot-ion to cause all parts of the surface presented to receive the same amount of treatment from the aforesaid member, because then those portions of such surface that were at and nearest to the axial center of the rotary member would be subjected to less frictional energy, since the speed'of the rotary member 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 member'is greatest. Thus it is plain that the work holder so manipulates the ball as to equalize the action of'the rotary member thereon.

where said axis may be said to fulcrum, but it is or may beflexible 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 aforesaid five positions of such axis. In this way the axis of rotation becomes an oscillatory-axis of rotation around the pr nclpal or main axis.

The-parts of the machme or, the suction work holders may beemployed, are briefly-described as follows: A

portion'of-a frame is represented at 6, which frame has head bearings 77 and caps 8-8' for horizont'al, rotary, ball-operating drum 9. At 11 appears a supporting stand for a horizontal, abrader-opeliating carriage I herein 'shown, and withwhicheither the electro-magnetic 12 which is reciprocable in a direction- 10m. gitudinally of the machine, theo'perating mechanism therefor being omitted. An upstanding support 13 and a friction member 15 thereon also appear. J ournaled in the frame 6, below but in the rear of the vertical plane of the axis of the drum 9, is a shaft 16. Secured to the outer end of the shaft 16 is a driving pulley 17 which is driven by a belt 18 from a main or ooun'tershaft '(not shown). Secured also to the shaft 16, inside of'the pulley 17, is a gear 19 that meshes with a small gear 20 loose on a stud 21 projecting from the outer end of the frame head and having its axis in line with the axis of the drum 9, Secured on the. inner end of the shaft 16 is a gear 22. Journaled in the longitudinal center of the frame 6 is a-shaft 23 which is driven from the shaft 16 through the medium of the gear 22 and a gear 24 secured to said shaft 23 and meshing with said first-mentioned gear. A short shaft 25 is journaled in the frame head and thls shaft has a gear 26 secured on .its outer protruding terminal to mesh with a large gear 27 on the outer end of the drum '9.

To drive the drum intermittently from the shaft: 23, through the medium of the

gears

27 and 26 and the shaft25, a clutch is provided, which consists of a cam-like clutch proper '28 and a disk 29 secured to the adjacent ends of said shafts, respectively.

These shafts are out of alinement, and the' clutch 28 has a peripheral tooth 30 while the disk 29 has two oppositely-disposed lugs 31 which extend to the left into the path of said tooth. Referring more particularly to vFig. 8, it will be seen how, as the clutch 28 gear 27, the drum 9 is caused to revolve lonefourth of the way around.

The ball-operating 'mechanism comprises the drum 9 and-the other parts and members operated thereby and closely associated therewith which w-ill new be described in de a lv,

kevolubly mount'ed or journaled in :the drum"9 andextendin beyond both ends thereof are 'fourspin les 32,- These spindles are arranged Eat equaldist-anc'es from longitudinal centeriof the drumhnd at'iequ'al" distances frorn-ach othe'r, andhRVeJSe ured on. their outer ends 33 which mesh with the constantly revolving gear 20. Each spindle 32 is provided at its inner terminal with a yoke 34, and slidingly mounted on-suchspindle is a sleeve 35 formed into a '5 cam,36 at the endadjacent to the drum 9.

A spring37 encircling each spindle 32 between its yoke 34 and a washer 38 .which bears against projecting parts'of the sleeve 35' on said spindle, and retains said sleeve opposite that which is pivoted to the supportin'gyoke 43' therefor, and these arms are pivoted at 4747 to the free terminals of the associated yoke 34, inside of the arms or branches of the same. If the pivots 47 are of insufiicient strength and rigidity to prevent the connected chuck, yoke and camsleeve from turningon the supporting splndle, saidsleeve can be keyed to said spindle 30 in the usual manner, or anyother suitable additional 'meansinay be employed to. that end. Each. chuck 45. has a core, 48 which projects from the barrel or spool of such chuck between the arms 46' and constitutes the actual holder for the balls. When the chuck is of the electro-magnetic'type, the core or holder proper 48 is made. of soft iron sothatonly the minimum amount of residual magnetism will be retained by it.

hollowed. or cupped more or less. to fit the balls and form agood and suflicient contact or connection therewith. g.

The roll 39 ineach case is so situated that on its spindle 32 far enou 'h toward the drum 9 to allow the axis 0 the associated chuck 45 to coincide with the axis of said" spindle, and, since said chuck swings at one end on an axis, represented by the pivots 47, the angle of inclination of the chuck axis changes asv the parts revolve with said spindle, because said sleeve is then recipro-l cated by reasonof the contact between 1ts cam 36 and said roll, and through the me-.

dium of the connecting yoke -43.- Thus the point of intersection between the spmdle axis,which is the principal or main axis correspondingwith the line 2 1n Fig. 6, and

revolution 'andthe oscillation of the chuck take lace, and is the center of the perfect The exposed end of this core or holder-isthe contacting cam-sleeve 35 can never slide the secondary axis or the axis upon whichthe chuck oscillates, representedjby the piv-' ots.47,' becomes the point about WlllCll t-hB from such point to the center of the holder 48 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 43 by the lines 5, in Fig. 6, in five different possible positions given them by the cam acting against the roll and moving the" adjacent end of said yoke along the spindle axis. By this means and in this manner aball in the holder receives the motion already very fully described. v v k To retain the ball firmly and securely in any holder 48, either electro-magnetism, or suction which is produced by a partial vacuum, is employed. I'will here explain the means for applying the former, leaving the explanation of the means for utilizing the latter untillater.

The drum 9 is provided with a commutator 49 for each chuck 45 when of the electro-magnetic type, and a brush 50fisprovided for each commutator, such brush depending from an insulated bracket 51 mounted -on the inner cap 8 and extending to the right over the commutators. Screws 52 are provided for the adjustment of the brushes 50, and binding-posts 53, as usual. Wires '54 lead from the binding-posts 53 to a suitable source of electrical energy, indicated at 55, in Fig. 1, and a wire 56 leads from such source to a non-insulated binding-post 57 'on the outer cap 8. Each commutator is connected, in the customary man ner, by a wire. 58 with a binding-post 59 set in an insulated bracket 60. attached to the drum adjacent to one of the spindles 32, and a short wire 61 connects such bindingpost with a brush 62. Each brush '62 is adjustably held in one of the brackets 60 by a screw 63.

, Secured to each spindle 32, with a ring 64 of insulating material between, is a contact ring-65 against which one ofthe brushes 62 bears. A wire 66 leads from each contact ring 65 to a binding-post 67 at the inner end of one of the arms or branches of the yoke 34 which is at the inner terminal, of the, spindle 32 upon which such ring is mounted, said wire passing from said ring through radial openings in the associated insulating ring 64 and spindle to a central longitudi i nal passageway 68 in said spindle,-as shown Fig; 4, thence through such passageway to said'yokc, out through a suitable opening therein, and along the outside of the yoke" arm which supports said bindingrpost to the latter, as best shown in Fig. 3, the afore-v said opening in theyoke being represented by dotted lines at 69. A short wire 70 connects the binding-post with a binding post 71 on the chuck 45 in this combination, and the circuit to the frame is completed.

through a short wire 72 which connects twobinding-posts 73.. and-74also on said chuck,

but the binding-post 74 being non-insulated.

The-binding-

posts

71 and 73 are the terminalsfof the electro-magnet which forms a' part-of each chuck 45 in this instance. Thus the circuit from the source of energy to any chuck 4'5 and back to such source is formed by the proper wire 54,

brush 50and commutator 49, and the wires 58 and 61, brush-'62, ring 65, and the wires and172-inthe combination, the frame Qfthe machine, and the wire 56.

The arrangement of the commutators 49 and the timing of the drum 9 are such that each chuck .45 or its holder 48 is magnetized and demangentized four times at every l'evolut'ion'of said drum, but all of said holders arenot magnetized and demagnetizedtogether. "When any holder 48 is magnetizedit attracts to itself and holds securely-any ball'that is a good subject for "magnetic-attraction when brought into the of such attraction emanating from such holdey, and releases said ball upon being demagnetizetl.

0f the abrader-operating mechanism with which this machine is provided, only the front-end ,portion of the carriage 12 and the front; end portions of two revoluble spindles 75, together with two abraders7 6 attached to said spindles, are shown. The abraders 76 are cupped in the centers of their working'faces to receive the balls, in much, thesa'me manner as are the holders 48, and when said abraders are in operative position the centers of the cupped portions thereof coincide or approximately coincide with the circular path at the left-hand ends of the horizontal diameters of the finished balls carried by the chucks 45. In other Words, the point of intersection between the oscillatory axis of rotation and the main or pnincipal axis around which such oscillatory axis revolves, of any chuck in grinding position is the same distance from the center'ofthe concavity in a juxtaposed abrader, that is, 'an abrader 76 the axis of which if-continu'ed would coincide with said main or principal axis, as itis from the center ofthe concavity in the holder 48 of said chuck.

. Of the ball-feeding mechanism with which the machine is provided, there are shown only a trough or raceway 77, the upper part of a support 78 for such raceway, and a brace 79 for such support. From its front end,'which is attached to the support 78, the raceway 77 curves rearwardly and slants downwardly to open at its back end toward the orbit of the holders 48 and at a point which is below the advanced position of the working face of the forward abrader 76. This raceway recelves the balls and delivers them to the holders. l The operation of the ball-holding mechasa whole is :as follows, it being asshaft and through the medium of the gear 24, causes the shaft 23 also to revolveconstantly. When the first ball 1 arrives at the discharge end of the raceway 77, said ball comes into contact with an energized holder 48 that is in position to receive it and to pick it from said raceway and securely hold it, the circuit to and through the chuck 45, of which said holder forms a part, being now closed by reason of the fact that the commutator 49 which belongs in said circuit has one of its electric contact segments in contact with its brush 50. Although the spindle 32 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 on such spindle, and the connection afiorded by the brush 62 which bears on said ring. \Vhile thus held by the energizing chuck 45 in question, which for convenience will be called the first chuck, the ball is carried thereby from the receiving position to the first abradingposition in line with the forward abrader 76, and is there acted on by said abrader. The first chuck with the ball is moved into the new position by reason of the fact that the clutch 28 on the constantly revolving shaft 23 engages the lugs 31 and imparts to the disk 29 and the shaft 25 one-half of a revolution, and that said shaft 25 in turn with its gear 26 imparts 'one-fourth ofa revolution to the gear 27 and the drum 9 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 clears said lugs and the movement of said drum ceases. The ball is rotated and oscillated in the peculiar manner previously setforth, and said ball is subjected on one side to the action of the forward abrader until the latter is retracted, when the clutch operates to give the drum another quarter turn.- Meanwhile the second chuck has picked the second ball from '120 the raceway 77 at the receiving position. Upon the second quarter of the revolution of the drum 9 the first ball is caused to traverse the friction member 15, and just after said ball reaches said member the first chuck is demagnetized, so as to enable the ball to roll in its holder on to be rolled therein by frictional contact with said mem= her, and just before said ball leaves said member Said chuck is magnetized again.

The first ball, thus turned half way around so as to present the undressed side to the rear abrader 76, is next left at the second abrading position, when for the second time the clutch 28 trees the disk 29 and the abradrs when advanced operate 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. Thus one side of each ball is dressed by-the forward abrader, and the other side by the rear abrader. The results produced by the third quarter ofthe revolution of the drum are that the first balLis dropped from its now demagnetized chuck, the second ball is carried to the second abrading position and turned half way around on the way, and

. the thirdball, which the third chuck has already picked, is brought into the first abrading position.- VVit-h the completion of ithe revolution of the drum, during the last ized so that it can and does pick the fifth 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 clutch operates at four regular intervals, the abraders are advanced and retracted four times, and each chuck is demagnetized twice, once when it passes the friction member 15, and once again when it drops the ball after the sec ond abrading.

Taking up, finally, the vacuum or suction devices illustrated on the last two sheets of the drawings, it will be seen that means fonhandling the balls with air take the place of electromagnetic means for that purpose, and that the drum 9 without the commutators, the driving mechanism for such om corresponding parts and the other construction.

drum, th'e'spindles 32 and their yokes, the spring-pressed cam-sleeves 35 and the rolls 39 therefor, and the holders 48, of the other construction, are all retained and do not atly differ, whenever they differ at all, members in Pointing out in detail the differences alluded 'to 1n the preceding paragraph, at-

tention is called to-the substitution of a shaft 80 for the stud21,.the narrowing of the intermediate gear 20 thereon, and the presence of an additional intermediate gear 81 secured to said shaft, with said gear 20, to mesh with .the gear 19, Fig. 11; and then to the flange or head 82 at the outer vend of each spindle 32, a rear passage 83,

which, unlike the wire passageway 68 in the firstinstance, extends the entire length of said spindle, branches at the yoke 34. which forms a part of the spindle,'and extends to the openings in the arms of such yoke atthe ends for the pivots 47, and air passages 8484; in said pivots. -Each pair of piv otsi 47 is here prevented from turning by means of two bolts 85 tapped into the free ends of the supporting yoke 34 into engagementwith said pivots. Mounted on the inner terminals of each pair of these pivots,

in practically the same way as the electromagnetic chucks are mounted, is an air orvacuum chuck 86 pivotally connected at 4A with two arms 87, these members being arranged and adapted to operate mechanically in the same way as do the chucks 4:5

and the yokes 43. Like the chucks 45, the.

chucks 86 have ball holders 48, and thereis a'branching air passage 88 in the head of each of said chucks 86, which passage leads from the center of the chuck holder to the openings in the chuck arms for the pivots that there is a clear air passageway from the left-hand open end of the holder of each air chuck, throughsaid chuck and by way of the connecting pivots to and through the supporting yoke 34 and the entire length of the supporting spindle 32. At the-junction of the

passages

83 and 84 such passages must be large enough, of

course, to-. enable the air chucks to rock, when the mechanism is in operation, without closing the same.

The axis of each spindle 32, in the suction or vacuum mechanism, corresponds with the line 2, in Fig. 6, and the chuck 86 and arms 87 assume the same positions while revolving as those indicated by the lines 3 and 5, in said View.

Suitably supported by a bracket 89 from the outer cap 8 is a case 90 having an annular air or suction chamber 91 therein, Figs. 11, 12, 14 and 15. The case 90 is sus-. pended between the gears 20 and 81, and

the shaft extends through the center.

thereof. The inner wall of the case 90 is provided exteriorly with two

annular flanges

92 and 93, the former being smaller than the latter. The flange 93 is an extension laterally of the periphery of the case 90. There is thus formed a circular channel 94. The chamber 91 opens into the.

channel 94: through two

arcuate slots

95 and 96 and a round opening 97 in the wall between. A pipe 98 leads from-the chamber 91, at any convenient point, to a pump (not shown) for exhausting the air from said chamber. Two radial ports '99 and 100are made in the flange 93- to establish commubeing secured in place on the open side of said channel by means of outer and

inner rings

102 and 103 fixed to'the edges of the

flanges

93 and 92, respectively. .Thussaid flanges form a journal for the coupling ring.

Equidistant from each other-in the coupling ring 101 are four recesses 104 formed in the left-hand face of said ring, and these recessed portions are further recessed, in the center of each at 105, to provide journals for the spindle heads 82, and slotted at 106, the slots being concentric with the slots 95and 96 and the hole 97. and opening through the plain right-hand side of said ring and through the recessed side thereof. Each head 82 is held in its recess 106 by means of a pair of abutting segmental plates 107 fastened in the recess 104 vided for their reception. The plates 107 have openings 108 in their abutting edges of a size to accommodate the necks ofthe spindles 32 or the portions of such spindles that are betweenthe heads 82 and the parts of said spindles upon which the pinions 33 are mounted, but not large enough for the passage of said heads. There are four radial ports 109 in the coupling ring, each of which opens at its inner end into one of the slots 106 at one end of the same, and at the other end through the periphery of said ring. The

ports

99, 100 and 109 are all in the same vertical plane in order to enable any one of the latter to be brought into alinement with either of the two former.

Clearly from the above the drum 9 in its rotation carries with it the spindles 32, as before, and rotates the coupling ring 101 which is securely attached to the outer terminals of said spindles by the plates 10?, such ring traveling around in the channel 9*, consequently each slot 106 is brought into open-communication with the

slots

95 and 96 and with the opening 97, one after another, and each port 109 is brought into alinement with the ports 99 and .100, one after the other.

Assuming that there is apartial vacuum in the chamber 91, and that the machine is running and the ring 101 has been turned so as to locate one of the slots 106 in open communication with the slot 96, air is being sucked through into said chamber from the holder 48 which is in communication through the connecting passages with said slot 106, or there is a suction at said holder, and such suction has suflicient force to hold a ball while being abraded. This suction commences as soon as the aforesaid slot 106 passes into open relation with the slot 90, and continues while a ball is picked at the receiving position, taken to the first'abradpro turns and carried said slot 106 into open relation with the slot 95, such relation being established before said slot 106-leaves said slot 96, and finally taken theslot 106 beyond said slot 95, and brought the communicating port 109 into line with the port 99.

The suction is thus cut oil and air admitted at the all'nmg ports or through the alining ports to break the vacuum, and the ball freed in this manner is rolled over or given a half revolution as it is carried past the member 15 and before the slot 106. which is new being followed in its course, arrives at the opening 97. \Vhen said slot does arrive at said opening. which is just as the ball-is about to leave the member 15, the vacuum is reestablished and said ball is advanced to the second abrading position. abraded. -and carried on to discharging position before said slot leaves said opening. Very soon after communication with the chamber 91 is cut off a second time, communication is had with the port 100, as shown in Fig. 15. the vacuum is again broken. and the ball in consequence permitted todrop from its now powerless holder. Bythe time said holder is in position to pick another ball, however,

its associated slot 106 will have once more come into open relationship with the slot 96. The operation of the air or vacuum controlling parts and members is alike in the case of each vacuum chuck. the same being energized twice and twice rendered powerless by the breakingof the vacuum at each complete revolution of the drum and"cou pling ring; and the constant and intermittent rotary and the constant oscillatory motions of the parts, including the drum, spindles and chucks. are the same as has been fully explained in connection with the electro-magnetic chucks and associated parts.

The vacuum chucks 86, as they appear in.

Fig. 1a, while relatively incorrect positions, are not as they would be if in the machine and occupying corresponding positions, because the case 90 is sectioned on lines 1414, Fig. 12.

The top and middle chucks 86 are energized and holding balls,-'and the bottom chuck S6 is dead, in Fig. 14. Werethese three chucks in the. same relative positions in the machine. and in operation, the upper-- most chuck would be without energy and' front end of the drum is represented in Fig.

14 by dot-and-dash lines.

The suction member, including the vacuum chucks, is designed to handle balls of Wood, ivory, and other substances and materials which, unlike balls of steel for eX- ample, cannot be handled successfully or at all by the electromagnetic chucks.

Obviously my invention is susceptible to considerable modification and change without departure from the spirit thereof, hence I do not desire or intend to limit myself to theconstruction set out herein.

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

l. A Work-holder, for spherical objects, comprising rotary object-holding means, and means to impart a conical rotation to the axis of rotation of said first-mentioned means.

2. A Work-holder, for spherical objects, comprising rotary object-holding means, and means to impart a changing conical rotation to the axis of rotation of said firstmentioned means.

A Work-holder, for spherical objects, comprising object-holding means, means to rotate said object-holding means on a principal or main axis, and means to impart an oscillatory rotation around said principal or main axis to said objectholding means.

4. In a machine for acting on spherical objects, an intermittently rotating member, a chuck carried by said member, and means to energize said chuck automatically at predetermined intervals.

5. In a machine for acting on spherical objects, an intermittently rotating member, a chuck carried by said member, means to energize said chuckautomatically at predetermined intervals, and means to impart a gyratorymotion to said chuck.

AUGUSTINE E. GREENE.

Witnesses:

' A. C, FAIRBANKS,

F. A. CUTTER.