GB830275A - Improvements relating to driving means for motorised cycles - Google Patents

Abstract

830,275. Variable-speed gear. UHER, E. Nov. 15, 1956 [Nov. 29, 1955], No. 34978/56. Class 80 (2). [Also in Groups XXVII and XXXI] A motorized cycle comprises two groups of gearing components, the first being driven by the engine of the cycle and including components producing an infinitely variable and automatically changing transmission, and the second group including a gear-wheel 33 adapted to be coupled with the first group and having a built-in pedal crank-shaft 32, means being provided by which a driven shaft 42 can be coupled with the second group with a reduction ratio or a step-up ratio as desired, or with both groups coupled together. As shown, the transmission is automatically varied by means of a V-belt drive, comprising a driving pulley 4, 6 and a driven pulley 20, 22 connected by a V-belt 7 and each consisting of a fixed half-pulley and an axially-displaceable half-pulley. The halfpulley 6 carries pivotally-mounted centrifugal weights 8 which are adapted to swing outwardly when the pulley is rotating rapidly and move the half-pulley 6 towards the half-pulley 4. The weights 8 have projections 9 bearing on an axially immovable cover 10. Half-pulleys 20 and 22 are urged together by a spring 23. A centrifugal clutch 12, 16 is arranged between the engine shaft 13 and half-pulley 4. The pulley 20, 22 is mounted on a shaft 19 to which a sprocket 24 can be coupled by means of balls 27 disposed in a transverse bore in the shaft 19 and projectable by means of an actuating key 28 into recesses in the sprocket hub. A chain 55 passes over the sprockets 24, 33, and a sprocket 45 on the shaft 42. A chain 56 connects a second sprocket 34 on the shaft 32 with a sprocket 44 on the shaft 42. A chain 58 connects a sprocket 43 on the shaft 42 with the rear wheel 57. For starting the engine with the cycle stationary, the actuating key 51 is placed in its middle position to uncouple the sprockets 44 and 45 from the shaft 42. Forward rotation of the pedals then rotates the engine shaft 13 through the shaft 32, sprockets 33 and 24, the V-belt 7 and an over-running clutch 17 (Fig. 2, not shown) arranged between the shaft 13 and the hub 3 of the half-pulley 4. To start moving, the actuating key 51 is released so that a spring 52 forces it into its left-hand position to couple the sprocket 44 to the shaft 42. By increasing the engine speed the rear wheel will then be driven through the centrifugal clutch 12, 16. In this position the drive can be assisted by the pedals when necessary. To disconnect the engine from the rear wheel 57 the actuating keys 28, 51 are moved to their right-hand end positions whereby the sprockets 24, 44 are released but the sprocket 45 is engaged. In this manner the shaft 42 and thus the rear wheel are driven with normal cycle transmission through the chain 55 by means of the pedals. A friction-wheel transmission can be used instead of the V-belt drive, and meshing gearwheels instead of chains and sprockets.