GB647500A - Improvements in or relating to tools for use in excavating and other operations - Google Patents

Abstract

647,500. Percussive drills. RICE, C. J. Sept. 22. 1947. Nos. 25730/47 and 11669/48. [Class 124] A chuck for a hand tool comprising a body portion, a chuck for receiving a bit, and a plunger having an extension forming a handle so that the plunger may be moved toward and away from the chuck, is adapted to permit the insertion and removal of the bit without dismantling and to present the inner end of the bit for direct impact by the plunger. As shown a bit 9 having a flange 10 is secured between the pivoted parts 2, 3 of a clutch which is held in the closed position by a slide 4. A plunger 5 which may have a ring 8 at the striking end slides in a tubular body 1 to deliver blows on the end of the bit. Other forms of clutch, e.g. without pivot pins, Fig. 7, (not shown) and with recesses to accommodate lugs on the bit, Figs. 16 and 17, (not shown) are described. The plunger may be locked in its innermost position by a pin 16 engaging in a bayonet slot 15 in a sleeve 7 or the locking device may comprise a rotatable non-sliding sleeve, Fig. 12, (not shown). The body and handle 6 may be covered with electrically insulating substance, e.g. rubber. A rubber washer may be used to cushion idle blows.