GB722997A - Improvements in or relating to epicyclic change-speed gears - Google Patents

Abstract

722,997. Change-speed gear. BIRMINGHAM SMALL ARMS CO., Ltd. Sept. 15, 1952 [June 14, 1951], No. 14079/51. Class 80 (2). In a cycle-hub wherein a simple sun-ring train with permanently fixed sun 16, provides reduced-, over-, and direct-drive by axial movement of a single input clutch-dog, instead of forming the clutch-dog as the usual cruciform member slidable between open-ended dogs projecting axially from the input sprocket hub 29, as in Specifications 527,629, 541,332, 591,678 and 644,179, it is formed as a dog-sleeve 17 having external splines 32 slidably and permanently engaging internal splines 31 in the input sprocket hub 29. In the extreme right position of the dog-sleeve 17, a cone 26 thereon lifts the tails of pawls 52, pivoted on the ring-gear shell 49, which pawls otherwise connect the latter to the output wheel-hub 36, whilst dogs 24 on the end of the dog-sleeve 17 mesh dogs 56 in the ring-gear shell which thus imparts reduced drive to the wheel hub 36 through the planetcarrier 39 and further crescent-shaped free pawls 47. In the central position of the dog-sleeve 17 its dogs 24 remain in engagement with the ring- gear dogs 56, but the pawls 52 are now released for direct-drive. In the extreme left position (shown), the dogs 24 of the dog-sleeve 17 release the ring gear dogs 56 and mesh dogs 48 on the planet carrier 39 which overdrives the wheel-hub through the ring-gear and pawls 52, the planetcarrier pawls 47 over-running. The dog-sleeve 17 is shifted through the usual diametral peg 11 in a hardened steel ring 19 formed of two semi-circular parts entered into a groove in the dog-sleeve through end-slots as described in Specification 722,998.