GB1347983A - Gear hobbing machine - Google Patents

Abstract

1347983 Gear-hobbing; beds and frames CHURCHILL GEAR MACHINES Ltd 14 Sept 1972 [27 Sept 1971] 44932/71 Headings B3K and B3B A gear-bobbing machine comprises a hob head 13, a worktable 15, a template 22 which causes relative radial movement between head 13 and workpiece 17, so as to produce crowning or taper hobbing, a push rod 27 arranged to move a stylus 23 into contact with the template, and means for automatically reducing the effective length of the push rod after the hob 14 has made a first cut and prior to commencement of a second out. The rotating hob 14 is traversed past the rotating gear blank 17 by vertical movement of a slide 12, and worktable 15 is urged to the left, Fig. 1, by a pneumatic or hydraulic actuator to maintain a stop 19 in contact with a stop 20. Template 22 is in the form of a segment of a right circular cylinder, is supported on a rod extending from a slide 12, and is angularly adjustable and adapted to be locked in the adjusted position by a handle 25. During vertical movement of hob head 13 template 22 is traversed past stylus 23, the transducer 24 of which adjusts the position of stop 20 through a serve system. The tooth depth is changed automatically between cuts by retracting push rod 27. This is done by hydraulic or pneumatic pressure which is applied to a spring urged piston 31 through an inlet 34, Fig. 3. The compression of spring 29 and therefore the depth of tooth, can be varied by a calibrated nut 35.