GB219434A - Improvements in variable speed mechanism - Google Patents

Abstract

219,434. Siddle, C. W. May 16, 1923. Variable-speed ratchchet gearing has its maximum speed set by arbitrary control and is variable automatically below that speed in accordance with the load. A driving-shaft 3, Fig. 1, has an eccentric sheave 4 adapted to turn upon a fixed eccentric 3', the whole constituting an eccentric of variable throw. A spring 17 tends to keep this eccentric in its position of maximum throw, but yields according to the load, so as to transmit lower speeds. The eccentric acts through a bearing 4<1> upon cams 6, Fig. 2, supported upon cranks 7<1> upon shafts 7, which are thus oscillated. Through one-way clutches 8<1>, shafts 8 are rotated in one direction. The cams 6 and a floating ring 6<1> surrounding them are arranged to make the impulses transmitted to the shafts 8 relatively long. A shaft 9 in line with the shaft 3 is driven alternatively forwards or backwards through two trains of toothed gears 11, 18 brought into action by a sliding double clutch 19. The maximum speed is determined by sliding manually a ring 16 which has a helical connection 14 with a slotted arm 14<1> engaging a projection 4<2> upon the eccentric 4. In this way the maximum throw of the eccentric is set. A one-way clutch 20 may be arranged between the shafts 3, 9 to allow the engine to be used as a brake upon a vehicle. In a modified arrangement, a crank is used in place of the eccentric.