Patent GB-1141092-A (GB)
Title: Improvements in processes and apparatus for making gears
IPC: B23F19/00
Filed: 1966-02-04
Abstract: 1,141,092. Making gears; forging; rolling. E. J. FLOWERS, and T. E. JOSLIN. 4 Feb., 1966 [5 Feb., 1965], No. 4921/66. Headings B3A, B3H and B3M. Apparatus for making gears comprises a forming tool which is oscillated relative to a workpiece blank or roughformed gear as the workpiece is rotated relative to the tool so that the tool contacts the workpiece with impact to form and/or finish the surface of gear teeth on the periphery of the workpiece. In one embodiment the workpiece 140 is positioned between master gears 80-82. The gear 80 acts as the forming tool and is rotationally mounted on an oscillating head 67. The head 67 is slidably mounted in a channel 66 and is connected through a pair of toggle links 68, 69 to the block 55. The central pivot 70 of the toggle links is connected to a crank-shaft 74 on a wheel driven through a belt 77 from a motor 76. Rotation of the wheel results in the slide 67 oscillating in the channel 66. The block 55 is mounted on a slide 54 and is reciprocable by means of a further pair of toggle links 56, 57 connected to an adjustably positioned block 52. Activation of a cylinder 61 causes a piston 60 to pull the toggle lines downwards resulting in retraction of the block 50. In operation, the block 55 is withdrawn, causing the gear 80 to retract to allow the workpiece 140 to be positioned and held against the gears 81, 82 and the gear 80 is returned to its original position. A drive assembly drives the gears 80-82 at the same angular speed to rotate the workpiece.. The slide 54 is moved progressively towards the workpiece and the oscillating means activated. The slide 54 moves forward until it abuts a stop 64. A time switch is provided to prevent over-working. The period of oscillation of the master gear 80 is such that 'it contacts the workpiece 140 as it rotates, causing the peripheral material of the workpiece to be moved away from the impact zones to form gear teeth. The number of teeth on the master gear 80 is preferably not equal to or a multiple of the number of teeth to be formed on the workpiece in order that any deformities of the master gear are not transferred to the workpiece. In a further embodiment, Fig. 7, an oscillating head 111 is slidably mounted between guides 112 and carries a master hypoid gear 120. A spindle 114 is supported in a sleeve 115 in alignment with the head and carries a hypoid gear 121. Bevel gear workpiece blanks 122, Fig. 6 (not shown), are positioned between the master gears 120, 121 and the head oscillated as the pinion gears (122) are rotated by the master gears. Alternatively, the pinion gears may act as the forming tool and either of the hypoid gears may be workpieces. If desired, a workpiece (130), Fig. 8 (not shown), may be rotationally mounted on a mandrel (131) and have a master gear forming tool (132). In this embodiment the tool is fed to the workpiece by rack-and-pinion means. The oscillations of the forming tools in the above embodiment may be attained by a fluid-actuated hammer (135), pulsating fluid columns, vibrating beams or hammers or other pneumatic, hydraulic, electric or mechanical means. The oscillations may be harmonic. Examples of the frequency of the oscillations, and sizes of the workpieces are given.