GB698122A - Improvements relating to helical gears - Google Patents

Abstract

698,122. Rolling. MORRIS COMMERCIAL CARS, Ltd. March 7, 1952 [Jan. 13, 1951], No. 1006/51. Class 83 (iv). [Also in Group XXIV] The acute-angled corners 16, Fig. 6, of a helically-toothed wheel are chamfered to avoid weakness at these corners. The chamber is formed by traversing the worked wheel while it is in mesh with a composite slave gear comprising a main helically-toothed part 1, Fig. 2, held between a pair of mutilated straighttoothed spur gears 2, 3. The pitch of the spur teeth is equal to the transverse pitch of the helical teeth and the spur teeth at each side lag slightly behind the helical teeth so that when the work is traversed in both directions the spur teeth form chamfers parallel to the work axis. The main part 1 has full width helical teeth over the segments 4, 5 where spur teeth are missing so that the spur gears are interlocked with the main part. The full width helical teeth roll on the chamfered teeth of the work to remove the burrs. In a modification each spur gear is formed with two segmental gaps each receiving a group of fullwidth helical teeth. A double helical gear 9, Fig. 5, is chamfered by being traversed while in mesh with two slave gears of opposite hand mounted on a common driving arbor 12 to which one only of the slave gears is keyed. Burrs on the end faces of the worked teeth are removed preferably by traversing a tool slide carrying three cutters, first engaging the ends 14, 15 of the teeth and then being shifted to remove the remaining end burrs.