GB618220A - Gear finishing - Google Patents

Abstract

618,220. Gear-cutting. NATIONAL BROACH & MACHINE CO. Nov. 4, 1946, No. 32694. Convention date, Feb. 18. [Class 83 (iii)] In a method of finishing a shoulder gear by a gear-like cutter meshing with the gear at crossed axes, the gear and cutter are moved across each other at right angles to the axis of the cutter. As shown in Figs. 1 and 2, the cutter C is moved across the gear G having a shoulder S from the full line position to the dotted line position, so that the centre of the crossed axes moves from a position on the shoulder side of the gear to a position on the opposite side. The machine shown in Fig. 3 comprises stocks 7 for supporting the gear arbor 8 and gear 9 on a vertically-adjustable knee 5, and a saddle 15 which carries a cutter head 16 and is angularly adjustable about a vertical axis to set the crossed-axes relationship of the gear and cutter. The cutter head 16 supports a cutter shaft 17 and cutter 18 driven by an electric motor 19 through a universallyjointed shaft 23 and bevel gearing 25, and is reciprocated horizontally on the saddle by a motor 26 connected by a universally-jointed shaft 28 to a screw 29 in threaded engagement with a bracket 30 on the cutter head. The cutter 18, which is in loose mesh with the gear on one side of its axis, is reciprocated across to the other side to give a cutting stroke, and then returned to the starting position to give a finishing stroke, the reciprocation being controlled by limit switches 31, 32 on the saddle and a dog 33 on the cutter head. Change gearing 20, 27 is provided in the two drives so that, respectively, the speed of rotation of the cutter can be varied according to the diameter and material of the gear, and the speed of reciprocation can be varied inversely to the amount of material to be removed.