Patent GB-1398674-A (GB)
Title: Gear making and testing machine
IPC: G01B21/20
Filed: 1973-01-30
Abstract: 1398674 Gear cutting; machine tool control W HOFLER 30 Jan 1973 [8 Feb 1972 (3)] 4599/73 Addition to 1344105 Headings B3K and B3B [Also in Division F2] In a machine for tooth-forming and testing involute spur gears, and of a type similar to that described in the parent Specification 1,344,105, wherein, in use, a gear workpiece is caused to execute both rectilinear and rotary movements combining to roll the workpiece, on its base circle, relative to a tooth-forming tool (e.g. a grinding disc, as shown) or testing tracer, and wherein adjustable cam means is used to determine the relationship between said rectilinear and rotary workpiece movements, the machine is arranged to be driven from a single position over a large range of base circle diameters without producing excessively high forces at the cam means. In Fig. 2, a workpiece support (7, Fig. 1, not shown) is rotatably mounted on a rectilinearly movable table 6 and is connected, via a slider 11 and a direction-changing 45 degree cam and follower 13, 14, to a slider 12 which is mounted on said table for movement normal thereto and is guided by a cam and follower 16, 18. The inclination of the cam 16 is adjustable and determines the relationship between the rectilinear and rotary movement of the workpiece support. Movement of the slider 12 to effect both said rectilinear and rotary workpiece movements is by moving the follower 18 which is connected to said slider 12 and is acted on, via a screw 20, by a motor 19 rotatable with the adjustable cam 16. The latter is releasably retained in an adjusted position by a clamp (17, Fig. 1, not shown), e.g. piston and cylinder operated. The workpiece support (7) may be connected to the slider 11 by a friction bar/disc device, rack-and-pinion or, as shown, straps 10 fixed to a cylinder portion (9) of the workpiece support and to the slider 11. Alternatively, the slider 11 may be omitted and the workpiece support connected directly to the slider 12. The grinding disc 4 shown is supported on a guide 2 which is angularly adjustable to suit gear helix angle. In Fig. 3, the slider movable normally of the rectilinear table is mounted on a stationary part of the machine. This slider, 26, is movable by a motor 27 via a screw 28 and carries cams 29, 31. The cam 29 has a follower 30 connected to the rectilinearly movable table, 22, on which the workpiece support is rotatably mounted, and the cam 31 has a follower 32 connected to a slider 25 which is movable relative to the table in the direction of movement thereof and connected, as in Fig. 2, to the rotatable workpiece support. The cam 29 may be of adjustable or, as shown, fixed inclination, e.g. 45 degrees or, preferably, to provide maximum base circle diameter range, 38 degrees to the table movement direction. The cam 31 is of adjustable inclination. The zero inclination of the cam 31, shown, provides for a base circle diameter equal to the diameter of the strap-engaged workpiece support cylinder portion. Smaller or larger base circles are provided for by adjusting the cam 31 on opposite sides of said zero inclination. When used for tooth-forming, the tool may be reciprocated or, with the tool stationary, the workpiece may be reciprocated, e.g. by piston and cylinder means. When used for testing, the tool is replaced by a stationary tracer.