GB1150059A - Method and apparatus for forming toothed parts - Google Patents

Abstract

1,150,059. Swaging. E. HANNA. 26 July, 1966, No. 33586/66. Heading B3H. In a method of forming a toothed contour on a workpiece, such as a gear-wheel, an unformed blank is passed axially through the central opening 51 of an integral continuous annulus 19, the opening having a tooth-shaped cross-section, each peripheral segment being complementary to a corresponding segment of the contoured workpiece, the height of the teeth 52 increasing axially along the opening to establish a tapered entrance throat, and an inwardly directed force P is alternately applied and released on opposing segments to flex the annulus elastically and displace opposing segments into and out of deforming contact with the blank, so that repeated impact of all sectors of surfaces defining said opening deforms the exterior of the blank as it is fed through the opening, to the shape of the opening. An apparatus for performing the method comprises feed carriage 11 which is driven by a screw 13 along a base 12. A spring-loaded push rod sleeve 16 is mounted in the carriage and engages the end of a blank 18. The forming die 19 has dog-clutch teeth at both ends and is non-rotatably held between a guide bushing 22 and a torque tube 25. A roller head 39 is mounted on a shaft 40 which rotates in bearings 41 about the fixed tube 25. Rollers 47 are mounted in the head 39 on eccentric pivot pins 46, by which the rollers are positioned so that as the head rotates they engage the crests of lobes 48 formed on the outside of the die. Each of the lobes 48 is opposite one of the teeth 52. The amount of deformation produced when the rollers engage the lobes is about À002 inches, and the minimum dimensions of the tapered die throat are larger than the finished dimensions of the workpiece by a similar amount. The work is fed into the die by the push-rod sleeve 16, but when the end of the sleeve engages the guide bushing 22, the feed is continued by a push-rod 33 which passes through the sleeve 16. In a machine for forming helical teeth the push-rod has a squared end which fits a recess in the blank, Fig. 10 (not shown). The rod is connected through changegearing to the lead screw 13 so that the feed and rotation of the blank are correlated.