Patent GB-965290-A (GB)
Title: New or improved machine for generating bevel and hypoid gears
Inventor: DEAKIN THOMAS MEYRICK
IPC: B23F23/00
Filed: 1961-11-10
Abstract: 965,290. Gear-cutting. DAVID BROWN INDUSTRIES Ltd. Oct. 31, 1962 [Nov. 10, 1961], No. 40265/61. Headings B3K and B3L. A machine for generating bevel and hypoid gears comprises a tool cradle 11, a work spindle member, means for angularly adjusting the axis of one of the members relative to the axis of the other, a first reciprocable slide 22 coupled in non-slip relation to one of said members for rolling the member about its axis, a second reciprocable slide 25, means enabling one of the slides to reciprocate the other, means 33 for adjusting the angular relationship between the first and second slides to vary the ratio of their amplitudes of reciprocation, and remote control means 62, 67 connected between the second slide and the other member for rolling the other member about its axis. The cutter 49 is rotated by an hydraulic motor 14 and is mounted in the cradle for angular and eccentric adjustment by slideway 20, Fig. 4, in a trunnioned member 17 rotatable about an axis 18 intersecting the cradle axis 12. The trunnions are carried by a slide 16. The slide 22 is attached by steel tapes 24 to a drum 23 on the cradle and carries a member 28 engaged by rollers 27 projecting from a block 36 pivoted on the under surface of the slide 25. The slide 22 is thus reciprocated and the cradle rocked when the slide 25 is traversed by a re-circulating-ball type screw 29 driven by an hydraulic motor 31. The slide 25 and motor are carried on a turret 33 which can be adjusted angularly to adjust the movement of the slide 22 from a maximum, when the slides are parallel, to zero, when the slides are at right-angles to each other. A work-feed slide 36 movable by hydraulic means carries a sub-slide 38 pivoted about an axis 39 intersecting the axis 12. The slide 38 carries a slide 40 on which a work-support 42 moves vertically and carries a reversible hydraulic motor 47 rotating a blank 46. The cutter represents the tooth of an imaginary basic crown wheel 50. The teeth cut may be straightsided or curved, including spherical. The movements of the slide 25 and the work-spindle 44 are co-ordinated by resolvers 52, 53, 55, 58 connected by gearing 56, 59 to the screw 29 and connected through a multi-pole changeover switch 60 and indexing gear 65 to an " Inductosyn " (Registered Trade Mark) 87 and a resolver 90. Valve means 110 control the speed and direction of rotation of the motor 31. The indexing gear includes a solenoid-operated lock 81 and an adjustable crank 75 associated with an operating piston 72 and racks 73, 77. The resolvers 53 and 90 operate over a coarse range and the resolver 52 and the Inductosyn over a fine range of movement. Resolvers 63 and 68 control the fine and coarse indexing movements. The change-over switch 60 is used to prevent unduly long strokes of the slide 25 when gears of small cone angle are being cut. In a modification, the work 119, Fig. 5, is rolled by the slide arrangement 120, 127. The electrical connecting means may be replaced by photo-electric means using the MoirÚ fringe principle, or electronic or hydraulic means. The cutter may be replaced by reciprocating cutters to generate straight teeth or a grinding wheel or wheels may be used. Twin intermeshing cutters may also be used. The tool may represent a non-generated wheel. The steel tapes may be replaced by rack gearing.