Patent GB-919227-A (GB)
Title: Improvements relating to gear generating machines
IPC: B23F9/10
Filed: 1961-05-05
Abstract: 919,227. Gear-cutting. GLEASON WORKS. May 5, 1961 [June 17, 1960], No. 16421/61. Class 83 (3). An intermittent indexing gear generator comprises a rotatable cradle 11, Fig. 2, carrying the work or tool spindle, a generating gear train (represented by broken line 30 running from pinion 34 to pinion 55) connecting the cradle and work-spindle 15, a work-indexing drive 81, 79 connectible to the gear train through a differential gear set 45 in the train, a first reversible motor 26 to drive the train and control the cradle rotation, and a second motor 91 to drive the train at a point between the differential set and the work spindle. The cutter spindle 13 is adjustable angularly in the cradle 11. The work spindle 15, Fig. 1, is adjustable vertically on a column 20 adjustable laterally on a slide 21 adjustable on a slide 23 about an axis 24 intersecting the cradle and work-spindle axes. The motor 26, Fig. 2, rotates the cutter spindle 13 through changespeed gear 29. The work-spindle is rotated from a ring gear 33 on the cradle through a ratio-of-roll-change differential 39, ratio-ofroll-change gears 42, the indexing differential 45, telescoping shafts 49, 52, index change gears 54 and the pinion 55. The generating chain is driven by the motor 26 through rateof-feed change gears 59, shafts 62, 64 and gears 67, 68 which rotate a drum cam 57. The drive can be disengaged by a clutch 95. The cam 57, Fig. 3, has a track 58 engaged by a follower 69 which oscillates a sector 70 driving angle-of-roll change gears 74 and gears 75, 34. The indexing drive is obtained from a gear 76 on the shaft 64 which rotates gears 77, the Geneva mechanism 79, 81, gears 82, 83, and the differential 45. The Geneva driver 79 is movable axially to control the indexing movements. To modify the rate-of-roll, a cam 84 is driven from a gear 85, through change gears 86 and a worm 87, to reciprocate a rack 88 and oscillate a gear 90. This oscillation is imparted to the differential 39. The rate-of-roll modifying train may be put out of action by removing one of the gears 86 and clamping the worm 87. The adjustable-speed reversible motor 91 is provided to obviate high gearing-up in the index gears 54 when a pinion having less than four teeth is to be produced. The slide 23 is moved to-and-from the cradle for controlling the position of the workpiece by grooves 96, 97 in the cam 57 co-operating with followers 101, 102 on a lever 98 adjustably connected to a piston-and-cylinder device 108, 109. The follower 101 is engaged for conventional gears and follower 102 for single tooth gearing G, P, Fig. 4, as described in Specification 919,226. This gearing is for automotive steering mechanism and has varying drive ratio and varying backlash. The varying ratio is obtained by using the cam 84 and the cam groove 97 moves the work in and out to give a reduction in pinion slot width. Initially, for generating a pinion with less than four teeth, both followers 101, 102 are disengaged, one of the gears 74 is removed, the Geneva driver 79 is put in permanent engagement with the member 81 so that the gear 83 turns three times for each turn of the cam 57 (or, if the pinion has a single-tooth, the driver 79 is disconnected and the member 81 is locked), the slide 23 is withdrawn, the cradle is at the bottom of a downroll and the lever 98 is clamped fast. The motor 26 is started and a solenoid valve 115 is actuated to operate the piston 109 which advances the slide 23 until the piston abuts an adjustable stop 112. Advance of the slide operates a switch 124 to start the motor 91. The cradle rotates counterclockwise until a switch 126 is operated at the conclusion of the uproll to stop the motor, reverse the valve 115 and withdraw the slide. At the end of the withdrawal, a switch 128 is actuated to engage the clutch 95 and reverse the motor 91 to cause a fast return of the cradle. Engagement of the clutch 95 causes rotation of the cam 57 and actuation of the Geneva mechanism 79, 81 to index the work. When all teeth have been cut, a counter driven in time with the cam 57, stops the machine. When a pinion P is cut, the slide is fed to cutting depth at a reduced speed by allowing fluid to escape from behind the stop piston 112 through a valve 142. For generating conventional gears, a gear 94 is removed to prevent operation of the motor 91 and the clutch 95 is locked.