GB381310A - Improvements in and relating to transmission mechanism for motor cycles - Google Patents

Abstract

381,310. Motor cycles. BUTT, E. E. W., 3, Orme Court, London. Sept. 9, 1931, No. 25342. [Classes 79 (ii), 79 (iii), and 136 (iii).] In a light motor cycle having provision for alternative pedal propulsion and comprising the combination with a large-ratio worm reduction gear of ratchet or free-wheel mechanism which permits the cycle to overrun when engine speed is exceeded, the worm wheel of the reduction gear is concentric with a pedal shaft connected to the driving sprocket wheel through free-wheel mechanism. The crank bracket may be enlarged to constitute a gear casing, as described in Specification 381,309. The engine shaft 4 is coupled by a dog-clutch 5 to a shaft 10 provided with a worm 9 gearing with a worm wheel 14, which is mounted on ball bearings 15, 16 and drives a sleeve 21 through a one-way clutch comprising an internal ratchet 31 engaged by spring-pressed pawls 32 on the sleeve 21, which is secured to a sprocket wheel 20 driving the rear wheel through the usual chain. The concentric shaft 17 of the pedal cranks 18, 19 drives the sleeve 21 through a one-way clutch comprising ratchet teeth 28 engaged by spring-pressed pawls 29 also carried by the sleeve 21. The end thrust of the worm shaft 10 is taken by a ball bearing 38. A friction clutch may be provided between the shafts 4, 10, and may be actuated by hand or automatically by the end thrust of the worm shaft. 10. Means for starting the engine by rotating the pedal shaft 17 comprises a skewtoothed pinion 41 slidable on the worm shaft 10 so as to be brought into driving connection with a clutch member 43 on the shaft 10. In this position, the pinion 41 meshes with a crown wheel 44 keyed to the pedal shaft 17, the teeth 45 of the crown wheel passing obliquely across those of the pinion 41.