GB998001A - Improvements in or relating to drive-transmission devices for rotary tools - Google Patents

Abstract

998,001. Change-speed gear. A. E. R. ARNOT. June 26, 1961 [June 25, 1960], No. 22346/60. Heading F2D. [Also in Division B3] A drive transmission device for rotary tools comprises a gear case 1 which carries an internally splined rotary tool-driving shaft 3, and a rotatable worm-shaft 8, which meshes with a worm-wheel 2 on a shaft 3, the ends of shaft 8 having recesses 12, 17 for coupling to a portable drill or the like. Shaft 8 has a gear 13 keyed thereto which meshes with a pinion 19 carried on a stub shaft 18 having a drill-engaging recess 25 therein. A pipe clamp 27 is secured to one end of casing 1, and comprises a vertically adjustable jaw 28, and a disc 32 having sets of serrations 35. A screw-threading die 54, Fig. 3, is splined into the bore of shaft 3, when screwing a pipe 55, or in a modification die sets or chasers are held in a holder 56, Fig. 7, which is carried in the shaft. A parting-off tool 54, Fig. 4, is held in a slot 60 in holder 56 by a spring 61, Fig. 7. Holder 56 is replaced by an internally and externally-splined member 69, Fig. 8, when drilling, the member co-operating with an externally splined tool-holder 64. A feed nut 70 co-operates with screw threads formed on the externally splined tool-holder 64, to provide a feeding movement for holder 64, the drilling thrust being taken by an abutment 94 when a distance tube 93 is held by clamp 28. Any of the drills 74, 78, 83 may be used in holder 64. Shaft 3 is rotated at selected speeds by applying a handle 52, Fig. 6, to one of the recesses 12, 17 or 25. The handle may be replaced by one of the couplings 37, 42, or 45, driven by a portable drill 39. Coupling 42 comprises a shaft coupled to a square driving peg 44 by a rubber disc 43. Coupling 45 comprises a flexible rotary shaft 46 in a protective shaft 47 which terminates in a square peg 48 and a protective cap 49.