Patent GB-1161699-A (GB)
Title: Gear Cutting Machine for Generating Hypoid Gears
Inventor: TAKAHASHI RYOSETSU
IPC: B23F9/10
Filed: 1967-05-04
Abstract: 1,161,699. Gear-cutting. YUTAKA SEIMITSU KOGYO K.K. 4 May, 1967 [5 Aug:, 1966], No. 20680/67. Heading B3K. A machine for generating hypoid gears comprises a cradle 19 carrying a continuously rotating face mill cutter 1, a work-spindle 58 connected to the cradle 19 through generating change gears 46, clutch 47, 48 and indexing change gears 55, and a reversing variable-speed motor 34 to oscillate the cradle and work, the work being indexed by operation of the clutch. The cutter 1 is rotated by a motor 30 through gears 31, 32, 23, 20, 15, 7, 8 in eccentric and angularly-related drums enabling it to be set at a predetermined angle and radius in the cradle 19. The cradle is rocked by the motor 34, its speed and direction of rotation being controlled by dogs on a control drum 41 oscillated in time with the cradle by a chain drive 39. A rack-cylinder 102 engaged by a piston 103 can be moved into engagement with a cam 101 on the cradle to cause an oscillating motion of the cylinder to be imparted through a reversing clutch 109, a clutch 43 and a differential 112 to the work-spindle 58. In operation, at the end of a generating roll, a cam 77 actuates a switch 77<SP>1</SP> to withdraw the work slide by an hydraulic means 67 and to change the speed of the motor 34 from low speed to high speed reverse. The dog 76 then moves the clutch 47 out of engagement against a spring 75 and allows it to snap back. Prior to the drive taking-up again, a cam 73 engages a switch 73<SP>1</SP> to slow the motor 34 to an intermediate speed. Indexing having thus been effected, a cam 78 actuates a switch 78<SP>1</SP> to cause the hydraulic means 67 to move the work back into the cut and the motor 34 to be reduced in speed from intermediate to low. The machine is stopped when all the teeth have been cut. In a modified setting of the machine, the clutch 42 is engaged and switches 119<SP>1</SP> and 120<SP>1</SP> are rendered operative so that actuation of the limit switch 77<SP>1</SP> then causes the work-slide 64 to be moved towards the cutter and the switch 78<SP>1</SP> causes withdrawal of the work without alteration in the speed or direction of the motor 34. In operation, a space 121, Fig. 4, is cut in the work from the small to the large end of the space. The work is then moved away and the cylinder 102 is moved into contact with the cam 101 so that, on reverse rotation of the cradle, an increment of rotation is added through the differential 112 to the work. Such reverse rotation with the work in contact with the cutter is caused by actuation of the switch 77<SP>1</SP> by the cam 77 which also causes the motor 34 to rotate at high speed. Thus, on the reverse swing, the effect of the differential is to cause a surface of larger spiral angle to be cut on one side of the tooth space, the amount of modification being adjusted by nuts 106 on the piston rod 103. When a tooth space has been cut, the cam 78 causes withdrawal of the work, the dog 76 indexes the work and a cam 120 changes the rotation of the motor to low speed in reverse and the work to be re-engaged. Operation of the machine can be reversed to cut a decreased spiral angle on the reverse cut.