(N 0 Model,) T. H. COSTELL, O, IATHE CHUCKJAW, No. 323,279, Patented July 28, l885, Zzz/

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N. PETERs. Photo-Lithographer, Washington, D.C. UNITED STATES PATENT OFFICE,

THOMAS H. COSTELLO, OF CHICAGO, ILLINOIS, ASSIGNOR TO H. H. GOSS, OF SAMIE PLACE.

LATH E a JAW.

SPECIFICATION forming part of Letters Patent No. 323,279, dated July 28, 1885. Application filed May 8, 1882. (No model.) To all whon, it may concern: placing the ring with its openings e over the Beit known that I, THOMAS H. COSTELLO, projections C on the bottom of the groove; of Chicago, county of Cook, and State of Illi but, on the other hand, when it is desired to nois, have invented certain Improvements in have the ring C held in position in a higher Lathe-Chucks, of which the following is a speci plane the said projections will hold it so upon 55 fication. the ring being moved around so far that the My invention relates to certain improve body of the same will rest upon said projec ments inlathe-chucks generally, and especially tions. These openings and projections are not to Such an one as is shown and described in designed to have any agency in moving the IO the Letters Patent of the United States issued ring C and annular gear C from a higher to a to me for an improvement in lathe-chucks, lower plane, or vice versa, for in my said Let dated the 13th day of June, 1882, No. 259,291; ters Patent I have described and claimed a and my said improvement claimed herein will special device for that very purpose, but mere be fully described hereinafter with reference ly to provide the said openings or recesses into to the accompanying drawings, in which which the projections are to be received and Figurel represents a cross-section of a lathe lkept out of the Way when not in use, to raise chuck embracing my improvement in its con the annular gear C into mesh with the pinions struction, taken as indicated by the broken a upon the screw-shafts a”. line 11 in Fig. 2, in which latter figure is rep Heretofore mere depressions have been used resented an interior view of part B, with an for the same purpose for which my holes or nular gear C and ring C in position in the openings e through the ring C are designed. groove in that part; Fig. 3, a like view of the That construction is objectionable, because same part with the gear and ring removed; such depressions weaken the ring too much, Fig. 4, a face view of the ring C"; Fig. 5, a de unless it be made much thicker and heavier 75 25 tail view of segmental parts of gear Cand ring than usual, and if that were done the case C in position together, and Fig. 6 a perspec would have to be made much deeper and heav tive of one of the jaws (t. ier, and would be more expensive and require A indicates one of the parts of the chuck; more material in its construction; and a still B, the other; C1, the jaws, and a the ridges and more serious objection would be that the said grooves on the portions of the jaws designed to depressions would have to be millied out, which hold against the Work or thing to be operated would be a separate and additional operation upon in the chuck. These grooves and ridges, to the one of casting the ring with the open instead of running in planes parallel to the ings through it, as shown in the drawings, for motion of the chuck, as usual in chucks here the openings would not add to the cost of cast 35 tofore, run at an inclination thereto, so that if ing the ring. the ridges on the jaws should cut into the ma In order to move the ring Caround in the terial of the work held by them such ridges groove back and forth, so that the projections shall, by reason of such inclination, acquire a may be either in or out of the openings, as re faster hold of the work, instead of merely cut quired, I employ the toothed wheel h, and 90 ting circular grooves in the same as they mount it upon shaft v, which turns in an open would do if run in the old way. ing through part B of the case, and have pro The part B is provided with a deep circular vided a part of the inner periphery of the ring groove, as shown, for the reception of the ring C with a series of teeth, t, as shown in Fig. 4, C and the annular gear C, and said groove is corresponding with those on wheel h, so that 95 45 provided on its bottom with three elevations, by turning the shaft v by means of the crank C, as shown in Fig. 3, and the ring C is pro H, or otherwise, the ring may be moved around vided with three corresponding openings, e, in the groove. The said ring C is provided extending entirely through the same, with the with three pins or studs upon its outer periph design that when it is desired to have the face ery, and the part B with three slots, b, for them, IOO SO of the ring C to rest solidly upon the bottom arranged correspondingly and inclining down of the said groove it may be made to do so by i wardly, as indicated by the broken lines in 2 - . 323,279 Figs. 2 and 3; and when the ring is moved back What I claim as my invention, and desire to and forth the studs travel in the slots b, and secure by Letters Patent, is these devices raise and lower the ring C, as The jaws a, having their holding-surfaces, specified in my said Letters Patent, and no by which they grasp the work, provided with 15 5 claim is made herein for the same. The ring inclined grooves and ridges a, substantially as C has to..be turned on both faces to render such and for the purpose described. tofaces be truemade and in onesmooth, of them and byif depressions milling, as hadbe- THOMAS H. COSTELLO. fore stated, the cost of its manufacture would Witnesses: to be materially increased above that of making L. F. MINZESHEIMER, both faces plain. M. M. DUVALL.