GB665783A - Machine key extractor for keys with or without gib heads - Google Patents

Abstract

665,783. Extracting keys from shafts. HARRISON, F. March 1, 1950 [Aug. 3, 1949], No. 20161/49. Class 61 (iii). Relates to a device for extracting machine keys used to attach fly wheels to crankshafts of internal combustion and steam engines and to attach pulleys and gears to shafting &c., and relates more particularly to the kind of tool including a body provided with inclined surfaces and a pair of jaws slidable thereon arranged to grip the key by relative displacement of body and jaws, and a drawbolt and nut by which withdrawal pressure is applied to the body, the invention consisting in a tool comprising a withdrawal device of said kind in combination with a drawbar for taking the reactive pressure applied by the nut to the drawbolt. As described the withdrawal device comprises a recessed body A, Fig. 2, providing inclined surfaces P<SP>1</SP>, P' along which jaws J<SP>1</SP>, J' are adapted to slide so as to grip the key, screws S', S' being provided to urge the jaws positively into engagement therewith, the body being formed to receive a drawbolt B<SP>1</SP> and nut N' by which means the withdrawal pressure is applied. A number of drawbolts of different lengths are provided so that one suitable to the length of shaft protruding beyond the key being extracted may be selected. A drawbar and drawbar mounting described but not claimed consists in a drawbar D', Fig. 4, formed from a pair of spaced side members and finding reactive abutment at one end upon the end of the shaft S<SP>3</SP> and at another point, adjustable along the drawbar, through a longitudinally adjustable tubular strut T which rests against the wheel, pulley or other member keyed to the shaft. The drawbolt B<SP>1</SP> passes between the side members of the drawbar and the nut N' bears against the outer edge. A plurality of struts T of different length may be provided.