Patent GB-694878-A (GB)
Title: Improvements in the production of straight-toothed gears and the like toothed parts
Inventor: CARLSEN LEONARD OVE
IPC: B23F5/20
Filed: 1950-11-10
Abstract: 694,878. Gear-cutting. GLEASON WORKS. Nov. 10, 1950, No. 27553/50. Class 83 (iii). A machine for cutting straight-tooth gears including bevel gears and face couplings or clutch members comprises two intermeshing milling cutters 10, 11 and means 95, 105 for simultaneously shifting the cutters to cut on opposite sides of a tooth-space. Cutters.-Each cutter has the teeth integral with the body, each tooth having one side 20, Fig. 3, lying in a plane perpendicular to the cutter axis and the other side 21 in a conical surface. If, however, crowned teeth are required, the sides 20 lie on a dished face. The side-cutting edges 20, 21, are straight-sided but may be arcuate or involute. The teeth may have alternate cutting-edges or each may cut on both sides, the angle between the edges being preferably equal to, the included angle between the opposite sides of a tooth space of the work to be cut. The tips and edges are relieved. The cutters are not traversed during cutting and hence are positioned to cut to full depth either at the ends or centre of the worktooth and are inclined according to the taper required in the tooth-space. Cutter-mountings; driving machine spindle; fly-wheels.-The cutters are mounted in a cradle 45 rocked by a worm-wheel 46, the cradle being j ournalled in a slide 41 which is movable to and from the work by a piston 105. The cutters are rotated from a central shaft 60 through bevel-gearing including gears 58 integral with sleeves 55 in which the spindles are slidably mounted. A fly-wheel 90 is interposed in each drive. Each sleeve 55 is rotatably mounted in a head 50 which is angularly adjustable about a shaft 86 which lies in a plane perpendicular to the cradle axis. Each head 50 is further mounted on a slide 92 which is rectilinearly adjustable on a slide 93 which is angularly adjustable about the cradle centre. These two adjustments permit variation of cone distance and taper. Each cutter is movable axially by an adjustable-stroke fluid piston 95, and is initially adjustable by nuts 53, 97. Work-holders.-The work is mounted on an angularly-adjustable slide 136 which, in turn, is mounted on a base 137 movable to-and-from the cutter cradle as in Specification 543,701. The work drive and indexing means may also be as described in that Specification. Operation. The cutters may cut in only one direction of roll of the cradle or in both directions. In the former case, all the teeth are first rough-cut and then finished. In the latter, each tooth is finished in one complete oscillation of the cradle. During a roughing-cut the cutters cut on their conical faces but, on the return roll, they are shifted in the directions of the arrows 32, 30, 301, Fig. 2, to cut on their finishing-edges 20, 201. These movements are made by the simultaneous operation of the pistons 95, 105. The pistons are controlled by a valve 115 actuated at each end of a generating roll by oppositely. directed, adjustable pawls 121 mounted on the cradle 45. During cutting, the cutters are either fed depthwise, or the correct depth is reached in the generating roll. The cutters may be rolled clear for indexing, but, preferably, the work is withdrawn. Form-cutting.-The angular adjustment of each cutter about the axis Y, Fig. 14, of the spindle 86 enables the cutters to represent any basic gear. Not only can it thus represent a nominal or true crown gear, or a mating gear, but, by positioning each cutter as shown and aligning the work axis W with the cradle axis X, gears can be cut having the same tooth form as the cutters, i.e. they are form cut even though a rolling motion takes place. Specification 694,938 also is referred to.