GB582738A - Improvements in or relating to chucks for machine tools - Google Patents

Abstract

582,738. Chucks. PATTON, A. M. April 15, 1944, No. 6980. [Class 83 (iii)] [Also in Group XXIII] Chucks and similar work-holders, of the type in which the jaws are attached to a spring back-plate capable of being distorted to apply the grip, have means permitting the application of increased pressure without producing unbalanced forces. As applied to a vice or holder for use in drilling, the chuck body 2 has a shank 1 for insertion in a lathe &c. tailstock and a flange 4 providing a seating for a ground spring-steel, plate 7 secured by screws 6. Two opposed jaw-carriers 8, 9 are attached to the plate by screws 12 and the jaws 14 are secured by screws 20 with concave heads 19 engaging the points of an adjustable screw locked at 17 and a screw provided with a hand-crank 18 for applying the closing pressure. The gripping- surfaces 15 are ground to be cylindrical in the closed position. The screws are carried by a loose ring 13, lateral swinging of which about the axis of the screws is limited by stop screws 22, Fig. 2 (not shown). In a modification for four jaws 29, Fig. 5, balanced pressure is applied by a chain of four pressure-applying links 31 connected by intermediate links 32. Surfaces 30, on the jaws, concentric with the chuck axis are engaged by opposed rollers 33 for one pair of jaws and by a flat-ended abutment screw 34 and a round-ended screw 35 for the other pair provide a pressure-applying device free to float, and are operated by a key applied to the screw 35. A further modification has a ring 38 carrying the spring plate 37 mounted to rotate about an axis Y-Y in a recessed back-plate 36 eccentrically mounted with respect to the machine axis XX. Indexing.-A series of recesses 39 coact with a plunger 40 to effect indexing as in drilling pitched holes.