Patent GB-303446-A (GB)
Title: Improvements relating to railway car braking apparatus
IPC: B61K7/04
Filed: 1928-12-28
Abstract: 303,446. General Railway Signal Co., (Assignees of Howe, W. K.). Jan. 3, 1928, [Convention date]. Arresting grips or friction apparatus on permanent way; force-transmitting mechanism.- Braking apparatus for railway vehicles of the kind comprising laterally movable bars arranged on the track for engagement with the wheel sides, comprises a pair of pivotal members or levers connected together by resilient means and each connected to one of a pair of brake bars disposed on opposite sides of a track rail whereby an equalized braking pressure is applied to the two sides of a wheel. The cross-ties upon which the track rails 15 are supported comprise I-beams 1 on each side of which are wooden beams 2. The brake beams 12 comprise sections articulated together by interengaging projections and slots on the adjacent ends of the sections so as to provide a continuous flexible beam. The sections are preferably of a length equal to that between the axles of a vehicle. The brake beams 12 are slidably carried on chairs or blocks 9, Fig. 5, secured to the cross-beams 1 and are guided for transverse movement by projections 9<b> on the blocks 9. Removable bars 26 preferably having the engaging surface disposed just above the level of the track rails 15 are secured to the beams 12. The operating mechanism for each pair of beams comprises a pair of levers 16, 18 having ball-ends engaging the beams and mounted respectively on a fixed pivot 17 and a pivot 19 the two pivots 19 being carried by a common sliding rod 11. The lower ends of the levers engage seats 20 on a rod 23 between which is disposed an initially compressed spring 21. As the system comprising the members 12, 16, 21, 18 is a floating one, means is provided for holding the beams in a definite normal position comprising a spring 30 abutting on the beam and on a bracket on the bar 11 so as to urge the lever 18 against the bracket. The rods 11 are supported on the cross-ties 1, 2 by projections 32b, 32<c> thereon riding upon wings 9<a> on the chairs 9 and plates 33. The rods are connected to the short arms of cranked levers 49 comprising upper and lower members pivoted at 48 between fixed longitudinal bars 40, 42 secured to the ends of the cross-ties 1, 2. The long arms of the levers 49 are connected to an operating bar 50 actuated by a lever 72 pivoted at 73 to the bar 40 and connected by an adjustable link 68, angle lever 61, link 60, to a crank disc 54 which may be rotated by an electric motor 56. The mechanism may be arranged to assume a number of braking positions and the angular position of the crank pin P of the disc 54 and also that of the lever 61 is such that the mechanical advantage of both of these members increases as the mechanism is moved from the zero position indicated in broken lines in Fig. 1, to the maximum braking position shown in full lines. When the mechanism is actuated to apply the brake, the movement of each pivot 19 of a lever 18 effected by the rod 11 directly effects the engagement of the one brake beam 12 of a pair with the side of the wheel and by actuation of the lever 16 through the spring 21, which is further compressed, applies the other beam 12 to the opposite side of the wheel with an equalized pressure. By moving the beams 12 outwardly until they are disengaged from the projections 9<b>, Fig. 5, the beams may be lifted to give access to the mechanism. This outward movement may be effected by first bringing the mechanism to the zero position, then disconnecting the pin 64 of the rod 68. moving the lever 61 to an intermediate position to enable the rod 68 to be connected to the point 77 and again returning the mechanism to the zero position.