GB650059A - Improvements in, or relating to, engine-assisted pedal cycles - Google Patents

Abstract

650,059. Engine-assisted pedal cycles. OBRAM, N. Jan. 13, 1948, No. 968. Convention date, Jan. 20, 1947. [Classes 79 (ii) and 79 (iii)] In an engine assisted pedal cycle having an internal combustion engine so mounted upon the rear wheel spindle and outwardly of the rear fork that it is adapted to drive the rear wheel hub through reduction gears enclosed in a casing fixed to the engine, the gear casing is so shaped and so fixed upon the engine that a part of the gear casing enclosing the final reduction gear is accommodated between one arm of the fork and the adjacent end of the wheel hub and the engine is located at the other side of the fork, the hub of the final gear being directly fixed to the wheel hub and the gear and hub being journalled on two bearings, one within the gear hub and the other within the opposite end of the wheel hub. As shown, the single cylinder internal combustion engine 17, having a decompressor valve 40, its petrol tank 27, its magneto 37, its carburettor 38 and the gear casing 31, 32 are mounted on an extension 61 of the rear wheel spindle 7 and by means of a slotted bracket 33 connected to a clamp 35 on the chain stay 42. In a modification (Fig. 3 not shown) the engine cylinder is arranged horizontally and instead of a magneto, the engine has a magneto-flywheel. The drive from the engine 17 is taken from the crank shaft by a driving gear 13 to which can be clutched a gear 11 driving the final gear 2 which is connected to the flanged end 45 of the wheel hub. The clutch mechanism comprises a spindle 10 rotatably carried in the gear casing and to which the gear 13 is secured, and on which the gear 11 is freely mounted. The gear 11 carries a male friction member engageable with a corresponding member on the gear 13. A rod 57 is connected at one end of the gear 11 and at the other end is threadably engaged with the casing, a compression spring 22 normally urges the rod 57 so that the gears 11, 13 are engaged. Connected at the other end of the rod 57 is an arm 20 operated by a cable 60 to disengage the clutch. The gear 2 has a sleeve 48 having a socket engagement with an aperture in the casing part 32 and the sleeve 48 has screw threads on its external periphery so that when the gear 2 is rotated for forward drive the threads tend to prevent oil leakage. The sleeve 48 is secured to the flange 45 by bolts 8. The other end of the hub carries the free wheel for the chain for normal pedal operation of the cycle. This end of the hub is mounted on the bearing 5 carried by the spindle 7 having an abutment 6. The other end of the spindle 7 has an axially adjustable abutment 29 and carries with some play a bush 3 on which is mounted the other bearing 30. A flange on the bush is bolted to the casing part 31 and the spindle is held in position on the cycle frame by nuts 44.