GB265700A - Improvements in or relating to the braking of vehicles and more especially of electric tramway and other cars - Google Patents

Abstract

265,700. Ireland, W. E. Nov. 17, 1925. Locking by frictional detents.-A device for automatically preventing backward movement of vehicles comprises a pawl-and-ratchet clutch device adapted to couple an axle of the vehicle to the usual hand or other mechanically operated brake the clutch being incapable of assuming an inoperative condition but being reversible in action so that it may be rendered effective for either direction of movement of a reversible vehicle. The ratchet clutch comprises a sleeve 29 secured to the wheel axle 2 and provided with flanges 36, 37 each having one or more oppositely directed teeth for engagement respectively with a pair of pawls 30, 31 keyed to a shaft 44 mounted in a disc 32 which is free to rotate in a bearing disposed between the flanges of the sleeve 29. To bring one pawl or the other into engagement with the corresponding toothed flange 36, 37, the pawl 31 carries a pin 46 engaging between projections 48 on a partly toothed pinion 47 gearing with a toothed ring 33 which can be given the necessary partial rotation by either of two cables 20, 21 attached to the ring and extending respectively to winding apparatus 23 disposed at the ends of the vehicle. The pawls are held in position in which one or the other of them is operative by the engagement of a projection on the pawl 30 with recesses in a spring-urged arm pivoted at 58 on the disc 32. The application of the brakes by the rotation of this disc 32 effected by the ratchet clutch device is effected by a cable 11 attached to the disc and to a drum 13 secured to a transverse rock-shaft which carries also a second drum with a cable 17 connected by a spring 18 to the usual brake lever to which is also attached the cable of the winding gear by which the brakes may be independently applied by hand.