GB787580A - Improvements in or relating to chucks - Google Patents

Abstract

787,580. Chucks; face-plates. BURNERD & CO., Ltd., F. (Gamet, L.). Sept. 1, 1955 [Sept. 2, 1954], No. 25541/54. Class 83 (3). A chuck in which jaw-carriers 6, in radial channels 5, are operated by eccentrics 8 rotated by levers 8a, comprises cavities 7, in the carriers, presenting opposite faces 7a, 7b against which the eccentrics bear, and shafts 9 supporting the eccentrics and journalled in the body of the chuck which has an axial-bore accommodating a member 13 operating the levels. The channels 5 are of T-section, and similar channels 20 are formed in the carriers to receive blocks 21 to which the jaws 22 are fixed by screws 24. The jaws, of tempered steel when gripping- teeth are provided, and of non-tempered steel when they conform to the shape of the work and have no teeth, bear against serrations on the front face of the carriers. A draw-bar 14 is connected by nuts 15-17 to the operating- member 13, which receives the ends of the levers in recesses 13a and is guided by a pin 18 riding in a slot 19 in the bore of the chuck. A dividedring 29a, 29b, in a groove in the bore of the chuck and the jaw-carriers 6, seals against the escape of lubricant from the interior of the chuck, the eccentrics being lubricated from the exterior of the chuck through passages 10 in their shafts 9. The front face of the jawcarriers is set back from the front face of the chuck in order that the latter may be used as a face-plate after removal of the jaws, radial grooves 26 and holes 28 being formed in the face of the chuck between the jaw-carriers to facilitate the clamping of work. Friction between the eccentric 8 and the faces 7a, 7b prevents the eccentric from sliding and releasing the clamping-pressure if the force on the draw-bar is released. In a modification, the member 13 may be operated by a nut 42, Fig. 5, or a screw rotated by bevel-gearing 44,45.