GB584339A - Finishing gear teeth by shaving process - Google Patents

Abstract

584,339. Gear-cutting. McLEOD, R. J. Oct. 17, 1944, No. 20070. [Class 83 (iii)] An attachment to a gear hobbing, shaping or planing machine to enable a roughed out gear to be finished by a shaving intermeshing generator cutter at the same setting comprises a base 1 for attachment to the machine 1a in place of the roughing cutter and carrying bearings for the finishing cutter 11. The latter has involute teeth conjugate to' those of the work and provided with cutting edges on the flanks, and the helical angle of the teeth may be the same as that on the work or different. The cutter is mounted on a freely running spindle 10 supported in journal bearings 7, 8 on a head 3 which is angularly adjustable on a slide 2 movable on guides 5 on the base 1. Axial movement of the spindle 10 in the head is prevented by a double thrust bearing 9. After feeding the cutter 11 into full mesh with the work, the latter is rotated and the cutter is fed along the work axis at a speed of from 0.0005 to 0.01 inch per revolution of the work to traverse the whole length of the teeth on the work. During this traverse the cutter and head 2 are reciprocated with an amplitude equal to or slightly more or less than the axial feed by means of a shaft 4 journalled at 12, 13 in the base 1 and having an eccentric portion 14 carrying an eccentric sleeve 15. The sleeve is rotatably adjustable on the shaft 4 through a serrated coupling 17 keyed to the shaft and locked by a nut 18,so that the eccentricity of the sleeve relatively to the axis of the shaft may be varied from zero to a maximum equal to the sum of the two eccentricities. The sleeve engages a block 19 stidable between horns 20 on the slide 2 so that the latter will be reciprocated when the shaft 4 is rotated by the cutter drive of the machine or by a separate motor. Alternatively the cutter may be reciprocated by an adjustable throw crank. The axis of spindle 10 may be set parallel to the axis of the work or in a crossed axis relation thereto, a graduated angular scale on the head 3 facilitating the setting, and the helical angle of the teeth on the cutter 11 may be equal to or less than that of-the teeth on the work. The direction of reciprocation of the cutter may be parallel to the teeth on the work or may be inclined at 15 to 20 degrees thereto by swivelling the hob saddle of the gear cutting machine on which the base 1 is mounted.