Work-holding drum for lathes

摘要

1,094,491. Work holding drum; machine tool details. WERKZEUGMASCHINENFABRIK GILDEMEISTER & COMP. A.G. Jan. 13, 1966 [Jan. 13, 1965], No. 1680/66. Headings B3B and B3T. In a shaft-mounted work-holding drum for lathes, a plurality of chucking positions are provided, each having a work-holding assembly comprising hydraulically operated actuating means. The work-holding assemblies are in the form of independent and exchangeable units. In an embodiment shown in Figs. 1-6 (Figs. 1, 2, 5, and 6, not shown) the drum comprises hexagonal plates 2 mounted on a central shaft 1, the plates 2 having recesses 21 at the chucking positions. Chucking slides 9 on each plate 2 are operated to grip a work-piece by an hydraulic piston 12 and cylinder 13 operated wedge 10 and clamping bar 11 arrangement. The clamping bars move radially to move the chucking slides and interconnecting pinions 19 acting on rack teeth 111 ensure equal movement of the slides 9. Figs. 3 and 4 indicate a separate piston and cylinder for each slide (9) whereas, in a modification shown in Figs. 5 and 6 (not shown), each piston rod 14 is connected to two clamping bars 11 by a rocker (20). The embodiment of Fig. 7 (not shown) includes a pair of work holding assemblies having three jaw (32) chucks operated by wedges (33) fixed to two pistons (23) that are moved in opposite directions by the hydraulic supply at conduits (6) and (7); the embodiment of Fig. 8 (not shown) includes a pair of work holding assemblies having collet chucks (34) operated by a pair of annular pistons (231) having tapered bores and moved in opposite directions hydraulically; and the embodiment of Fig. 9 (not shown) includes an expanding jaw (37) device for gripping internally hollow workpieces, the jaws (37) being operated by a conical extension (39) on each of a pair of pistons (2311) that are moved in opposite directions hydraulically.