Patent GB-844659-A (GB)
Title: Improvements relating to gear cutting machines
IPC: B23F23/04
Filed: 1958-03-31
Abstract: 844,659. Gear-cutting. GLEASON WORKS. March 31, 1958 [March 29, 1957], No. 10293/58. Class 83 (3). A bevel gear-cutting machine comprises a work spindle 17 to support a workpiece G so that the periphery of a cutter 14 is substantially tangential to the root of a tooth-space to be cut, the cutter consisting of a number of radial blades 15 with a gap 80 between the first and last blades, to permit indexing of the work and to allow a work-loading device 87 to remove and load workpieces from the work spindle. The cutter 14 rotates about a vertical axis on a slide 12. A slide 23 is movable transversely of the slide 12 by an adjustably-mounted piston 25, and carries a slide 21 on which a workhead 18 is angularly adjustable. The cutter is rotated by a motor 28, Fig. 6, through beltgearing 31, 35, a magnetic clutch and brake unit 37, and bevel gearing 39, 40. The motor 28 also rotates a further gear 41 meshing with the gear 40, the gear 41 being rotated through a back-lash eliminating spring-drive 48 as described in Specification 842,516. The motor 28 further rotates a pinion 53 to drive a shaft 54 carrying a cam-drum 55 which reciprocates a pump piston 57. At each reciprocation of the pump 57, a piston 75 is moved to oscillate a Geneva drive-pin 71 which indexes the work G. The Geneva mechanism may be as described in Specification 818,888. The shaft 54 also carries cams 79 co-operating with rollers 82 to reciprocate the cutter slide 12, and cams 83, 84 actuating switches 85, 86 to control a counting device, the motor 28, the clutch brake unit 37 and a work-loading motor 105. The workloading device 87 has four arms each carrying work-holding jaws 89, Fig. 2, and carries a blank successively from a shoot G 1  to the cutting station G 2  to a gauging position G 3  and then to a position G 4  where it is ejected into a shoot 91, Fig. 1. The jaws are opened against the force of springs 94 by plungers 95 which are permitted to advance under the pressure of springs 97, by an axially movable cam-bar 99. The cam-bar is shaped so that the jaws remain closed at the gauging station G 3  and are only partly opened at the loading station. The work-loading motor 105 rotates a cam-shaft 109 so that the following sequence of operations occurs: the jaws 89 are closed by retraction of the rod 99 by a cam 129, the head 87 is advanced by a cam 117, a pinion 123 engages a gear 125 which is rotated 90 degrees by a Geneva mechanism 128, 127 to index the head 87, the head is withdrawn, and the jaws are opened. A cam 113 then actuates a switch 114 to stop the motor 105 and start the cuttermotor 28. Gripping and release of the work is controlled by an hydraulic valve 112 on the shaft 109. The valve may also control the piston 25 to withdraw the workhead between operations if a gear is too long to be accommodated in the recess 80 of the cutter when the loading head 87 is advanced. The gear blanks are allowed to drop one at a time on to pins 139 at the bottom of a shoot 90, Fig. 7, by release pins 137, 138 controlled by a cam 135 on the shaft 109 through linkage 140, 143, 150. At the ejecting station, as the loading head is retracted., the finished gear engages a lever 155, Fig. 1, and compresses a spring 157. When the jaws are opened, the spring 157 causes ejection of the gear into the shoot 91.