Patent GB-692344-A (GB)
Title: Machine for shaping gears
IPC: B23F5/16
Filed: 1949-03-21
Abstract: 692,344. Gear-cutting. FELLOWS GEAR SHAPER CO. March 21, 1949 [March 24, 1948], No. 7669/49. Class 83 (iii). [Also in Group XXIV] A gear-shaping machine comprises a gearshaper cutter supported on a reciprocating spindle 640 whereby the cutter will be rocked on cutting engagement with a work-piece W, the spindle being supported on a head 600 which is adjustable in a direction parallel to the spindle axis and means being provided for locking the head in adjusted position. One or more gear blanks W are carried by a head 800 adjustable along ways 12. The cutter, which is of the flexible double-cutting type described in Specification 655,251, is carried by the head 600 on ways 13. The gear and cutter may both be supported by outboard bearings. The rotation of the gear and cutter and the in-feed of the work-head 800 may be continuous or intermittent. The work-head 800 may also be traversed rapidly to and from cutting-position or be fed by a hand-wheel 220. The workspindle is rotated by an electric motor 15, Fig. 6, the drive including a shaft carrying a flexible coupling and a fly-wheel, change gearing, bevel gearing 27, main shaft 28, worm 37, gears 47c, 49, reversing-gears 51-53, a gear and cutter drive clutch engageable with a bevel gear 60, gearing 68-71, splined coupling 73, worm 835, Fig. 34, and worm-wheel 840, which is adjustable to take up back-lash. The same drive via bevel 60, Fig. 6, also rotates the cutter through bevel 61, splined shafts 30, and 651, Fig. 21, bevel-gears 654, gear 657 and timing gears carried on an adjustable plate 665, worm 661 and worm-wheel 674, which is also adjustable to take up back-lash. For intermittent rotation of the gear and cutter, the gear 47c, Fig. 6, is removed and replaced on a shaft 48 at 47i so that it continues to mesh with the gear 49. The shaft 48 is then intermittently rotated from the main shaft 28 by a bevel gear 40 rotating a cam 83 which actuates a ratchet-drive 89, 90 provided with an adjustable masking device 96. The work-head 800 is fed intermittently by a cam 82 coaxial with cam 83 and actuating a similar ratchet device 123, 124, an adjustable masking-plate 126 being provided which may be released by a solenoid 130 to cut out the ratchet feed. A cam-bar connected to the solenoid 130 moves a toothed clutch for engagement by teeth on the hand-wheel 220 so that the head may then be adjusted manually. The ratchet-wheel 124 rotates the work-head feed-screw 31 through gearing including a friction slipping gear 154. The cams 82 and 83 may have only one lobe if the cutter is required to cut in one direction only such as when cutting shoulder gears. When the masking- plate 126 is in position, the work-head is fed continuously from a worm 38 on the main shaft 28. The worm 38 drives the screw 31 via a friction-type clutch 162, Fig. 14, operated by a yoke controlled by a solenoid. The screw 31 contains a push-rod 200 to engage an abutment in the work-head, the abutment being finely adjusted by screw means and a gauging dial to determine the exact depth of cutting engagement between the work and cutter. Movement of the rod 200 actuates a limit switch LS3 to energize a constant-torque electric motor 210 which holds the work-head in correct position. The work-head is held on the ways 12, Figs. 2 and 34, by hold-down strips 803, 804 and an adjustable gib 802, the way associated with the gib 802 being arranged to take the thrust of the cutting operations. The feed screw 31 is received in a nut 805 secured in the head. The cutter-head 600 is adjustable along the ways 13 by a nut 610, Fig. 26, engaged by a manuallyrotated worm 614, and engaging with a screw fixed to the machine frame 10. The screw and nut are locked by a second nut 611 which is engaged by a metal-washer forced axially towards the nut 610 by a rubber ring engaged by a manually operated plunger 625, Fig. 23 (see Group XXIV). The cutter-head may also be locked in position by adjusting gibs 604. It is then clamped to the bed by holding-down strip 606. Helical gears.-The cutter-spindle carries a splined sleeve 680, Fig. 26, the splines being helical when such gears are required. The sleeve 680 is connected to the driving wormwheel 677 by a conical sleeve 681 which is adjustable longitudinally to compensate for wear. Balancing mechanism.-The cutter-spindle 640 is reciprocated by the motor 15 driving through the splined members 30, Fig. 6, 690, Fig. 23, a vertical shaft 695, and a balanced variable-throw, crank mechanism 710. The crank mechanism oscillates a gear segment 717, Fig. 24, carrying a balancing mass 719 and meshing with the teeth of a sleeve 642, Fig. 26, surrounding the spindle. A similar segment and mass 724 are mounted on the opposite side of the sleeve. Operation.-In operation, a push-button energizes a counting-device and starts the motor 15, a coolant motor 290 (which can be cut out by a hand-switch), and the electric motor 210. The work-head is then traversed rapidly by the motor 210 while the gear and cutter are reciprocated and rotated relatively, a selector switch being set to give continuous or intermittent operation. When cutting position is reached a rod 812, Fig. 36, is moved by a stop on the head to actuate a limit switch LS2. According to the positions of two hand-set selector switches and of the gear 47, the work-head is then advanced either continuously or intermittently with or without continuous or intermittent rotation of the work and cutter. In-feed is stopped by the rod 200 actuating a switch LS3, Fig. 14, to release the clutch 162, or in the case of intermittent feed, to return the masking plate 126. The motor 210 is also actuated to hold the head in position, and, if necessary, the gear and cutter drive clutch is re-engaged. During cutting, a worm 42, Fig. 6, on the main shaft 28 rotates a cam 251 coacting with a push-rod to actuate a limit switch LS1. The limit switch is connected to the counting device which is pre-set manually to stop the motors 15 and 290 and to reverse the rapid traverse motor 210 when cutting is complete. Stop-motions.-The cycle is completed by actuation of the switch LS4 by the rod 812 which stops the machine. The solenoids which actuate the clutches in the machine are associated with time delay mechanism, such that, if there is any mechanical failure, the machine is stopped. Specification 692,410 also is referred to.