GB531627A - Motorizing unit for bicycles - Google Patents

Abstract

531,627. Motor cycles; driving gearing. DEHN, F. B. July 6, 1939, No. 19756. [Classes 79 (ii) and 79 (iii)] In a motor unit for attachment to a cycle the engine' A is supported above the pedal crank shaft M and drives through belt gearing 27 a roller E mounted in a supporting member 30 which is located below the pedal crank shaft and is manually controlled so as to bring the driving roller into and out of engagement with the rear wheel of the cycle. In the construction shown the engine A is pivoted at 10 by means of a plate 8 to a frame tube K and is slidably supported at 19, 20 by a bar 14 which is pivoted at one end at 16 to the frame tube K and at its other end is slidably supported in a clamp 23 on a frame tube J. The plate 8 is adjustably clamped at 9 to the engine. A lug 19 on the engine is forked downwardly so as to straddle the bar 14, thus permitting relative vertical and horizontal sliding movements between the lug and the bar. The member 20 is a plate clamped to the engine and having a hole through which the bar 14 can slide. The engine shaft carries a pulley 26 connected by a belt 27 to a driving pulley 28 rigid with a friction roller E adapted to engage the rear cycle wheel F, the belt also passing over an adjustable tensioning pulley 29. The pulleys 28, 29 are carried on the ends of a bell-crank member 30 pivoted at 35 to a clamp 33 on the rear wheel fork R, the member 30 being rocked about its pivot 35 by a hand lever 40 and Bowden wire 42 so as to bring the roller E into engagement with the road wheel to drive the latter. The pivot 35 is so situated that as the roller engages the road wheel the belt is tightened. The relative dispositions of the pulleys 26, 28, 29 is such that the belt 27 passes on either side of the pedal crank spindle M and does not interfere with the pedals.