GB343979A - Improvements relating to the operation of railway signals - Google Patents

Abstract

343,979. Railway signals &c. EDEY, R. M., 2, Godfrey Mansions, Garden Reach, Calcutta, India, and WESTINGHOUSE BRAKE & SAXBY SIGNAL CO., Ltd., 82, York Road, King's Cross, London. Nov. 27, 1929, No. 36356. Convention date, Feb. 5. [Class 105.] Hand - levers and hand gearing ; wire and like compensators ; wires for operating signalling apparatus.- Signal hand-levers are connected to the signal wire by mechanism so arranged that the manual effort required to be exerted on the lever is substantially constant throughout the whole stroke of the lever. The leverage ratio is at first large to take up the slack of the wire rapidly and thereafter diminishes during the actual pulling-off of the signal. The arrangement may comprise a bell crank 3, 4, Fig. 2, in which the effective arm X for the hand-lever connection 9 increases during the stroke while the effective arm Y of the signal wire 5 is at first constant and then decreases. In Fig. 9 is shown an arrangement in which a roller 36, to which the signal wire is connected, is constrained by a link 37 to move inwards on the tail 33 of the handlever 34. Fig. 10 shows an arrangement similar to that of Fig. 2 with the addition of a device for compensating any expansion or contraction of the wire. The signal wire passes over pulleys 43, 46 on a triangular member 39 and is maintained under tension by a weight 47. On actuation of the hand-lever the connection 48 causes a gripper member 45 to engage the wire and thereafter the triangular member 39 moves about its pivot 40 acting in the manner of the bell crank construction. The triangular member 39 normally rests against a stop 52. Other arrangements comprise cam slots in sliding or rotatable members, a spiral cam actuated by a rack connected to the hand-lever, and a bell crank similar to that shown in Fig. 2 arranged in the run of the wire.