GB636124A - Improvements in and relating to removable bicycle motorising devices - Google Patents

Abstract

636,124. Motor-assisted cycles. SOC. DITE A.B.G. December 30, 1946, No. 37981. Convention date, November 29. [Classes 79 (ii) and 79 (iii)] A detachable auxiliary engine unit for bicycles of the type having a speed reducing gear driving a ring gear secured to the spokes, the whole being mounted on an extension of the rear wheel spindle, has a friction clutch which is actuated by rotation of a pinion carried by the unit, the pinion being rotated from a hand lever through transmission means adjustably connected to the pinion. The transmission means is preferably connected to a lever which is adjustably clamped to the pinion. The crankcase 2 of the engine 1 has a lug 3 by which the assembly is eccentrically mounted on an extension 16 of the rear spindle 4, Fig. 3. The eccentric bush 15, disposed between the spindle extension and the mounting lug is adjustable and can be locked in various positions by a pin 18 which can be inserted between teeth 17 formed on the bush into the lug 3, and held therein by lock nuts 19. The lug 3 has an extension 6 which is anchored to the chain stay 7 either rigidly, or resiliently as shown. To adjust the tension of the driving chain 10, the bolts securing the arm 6 to the chain stay 7 are slackened off, the nuts 19 removed and locking pin 18 withdrawn whereupon the eccentric bush 15 can be rotated. The carburettor 13 is preferably arranged with its float chamber disposed on the rear wheel axis. The engine may be declutched from the wheel driving sprocket 9, Fig. 4 by the cable control 35 which rocks the lever 34 to displace the plunger 29 against the key 27 working in a slot 28 in the spindle 8, whereby the conical inner clutch member 26 is moved to the right against spring pressure to separate it from the outer clutch member 24, since the outer clutch member has teeth 25 and is engine driven, and the inner clutch member is splined to the spindle 8 to which the driving sprocket 9 is keyed, such operation of the cable control 35 declutches the engine.