GB913095A - Hub clutch controlled by back-pedalling, for motor-assisted cycles - Google Patents

Abstract

913,095. Friction clutches; ratchet clutches; controlling clutches. ATELIERS DE LA MOTOBECANE. April 11, 1961 [July 15, 1960], No. 13032/61. Class 80 (2). [Also in Groups XXVII and XXXI] A clutch arrangement for a power-assisted pedal cycle comprises a multidisc clutch 24, 25 which is engaged by back-pedalling to turn a sprocket 16 and screw a nut 34 leftwards of the Figure along helical slots 42 in a sleeve 7 fast with the sprocket, thus connecting a hub 10 carrying the rear wheel of the cycle to a sleeve 6 and a sprocket 13 connected by a chain to the cycle motor for starting the motor, the motor when operating driving through the sprocket 13 and the sleeve 6 to a roller ratchet clutch 20 and thence to the wheel hub 10. The clutches are supported upon a non-rotary axle 1 splined at 29 to support an axially slidable clutch control ring 30. A cup-shaped connector 32 carried by the clutch ring 30 has spring tabs 33 frictionally engaging the outside of the nut 34, which has frusto-conical surfaces 35, 37 for engagement with the clutch ring and with a bell-shaped clutch member 39, respectively. A thrust bearing 31 lies between the clutch ring 30 and the end-plate of the multidisc clutch 24, 25, the discs of which are of external polygonal and internal square cross-section for engagement with correspondingly-shaped recesses in the wheel hub 10 and the periphery of an extension of the sleeve 6. The bell-shaped clutch-member 39 is also of external polygonal cross-section, to engage in the correspondingly shaped part of the wheel hub 10. On back-pedalling, the sprocket 16 and the sleeve 7 fast therewith rotate, so that inwardly-projecting lugs 41 on the nut 34 are screwed leftwards along the helical slots 42 in the sleeve, against the light friction drag on the nut of the spring tongues 33. The frusto-conical surface 35 on the nut 34 then engages the clutch ring 30, which slides leftwards along the fixed axle splines 29 and, through the thrust bearing 31, engages the multidisc clutch 25, 27. If the cycle has already been set in motion, the inertia thereof is transmitted from the wheel hub 10 to the sleeve 6 and the cycle motor is started. When the motor has started, and the rider no longer back-pedals, the nut 34 is screwed rightwards to an intermediate position, drive then passing from the motor through the rollers 20 of the ratchet clutch, these rollers being retained in a cage 21. If the cycle is at rest and the rider pedals forwardly, the sprocket 16 and the sleeve 7 rotate in the opposite direction, and the nut 34 is screwed rightwards along the helical slots 42, so that the frusto-conical surface 37 on the nut engages a co-operating friction surface on the bell-shaped clutch member 39, whereby rotation is transmitted thereto and thence to the wheel hub 10. The cycle motor may drive through a single or double centrifugal clutch, or through a centrifugal clutch and ratchet clutch combined. Specifications 753,117 and 862,161 are referred to.