GB204998A - Improvements relating to slack adjusters for fluid pressure braking apparatus - Google Patents

Abstract

204,998. Tomlinson, A. V., (Westing house Air Brake Co.). Jan. 19, 1923. Compensating for wear. - A slack-adjusting device comprises a separate fluid-pressure cylinder carried by and adapted to adjust the length of the tie rod which extends between the usual brake levers connected to the main brake cylinder. The tie rod 4, Fig. 4, which is pivoted to levers 23, 24 operatively connected to the main brake cylinder 25, comprises in one form end members 28 telescoping into members 30 bolted to the subsidiary cylinder 29 within which work the pistons 33, 33' connected by a rib 34 having a guiding projection 17. A pawl 37 is pivoted on the rib 34 and engages a ratchet 31 on a rod 32 the ends of which are screwed into the parts 28 of the tie rod. If there is excessive slack in the brake rigging, the piston of the main cylinder 25 moves sufficiently to uncover a port whereby compressed air is supplied by the pipe 38 to the space above the piston 33 which is thereby moved to compress springs 35, 36. When in the release of the brakes, the cylinder is exhausted, the springs 35, 36 return the piston 33 and turn the ratchet 31 by the pawl 37 thus shortening the effective length of the tie rod. For resetting the adjusting means the hub of the ratchet 31 may have a bevel wheel 39 gearing with a bevel wheel 39<a> on a shaft 40 having a squared end 41 to which a handle may be fitted. The pawl 37 may be disengaged for the resetting operation by a bell-crank lever 42 pivoted on the rib 34 and actuated by a notched pin 43 provided with a handle 44. The engagement of the lever 42 with the notched pin also serves to prevent the springs 35, 36 from completely moving the piston 33 out of the cylinder when taking down the cylinder. Relief wedges 21 are provided for engagement with the ends of the screwed rod 32 when the maximum amount of adjustment has been effected ; these wedges may be tapped on the under side to permit the pawl 37 and piston 33 to complete their stroke. Other forms are shown in which adjustment of one end of the tie rod is effected; in which the ratchet-wheel 31 is formed on a nut which turns on a screwed rod fixed to the part 28 and in which the tension in the tie rod is not transmitted to the cylinder 29.