GB1091662A - Brake automatic slack adjusters - Google Patents

Abstract

1,091,662. Automatic brake adjuster. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. May 5, 1965 [June 1, 1964], No. 22583/64. Heading F2E. An automatic slack adjuster comprises an element movable in an endless path in steps and being so stepped during each brake operation when the brake slack is greater than a predetermined value, the element passing through a predetermined position in that path to actuate mechanism to effect reduction of slack. The adjuster comprises an arm 2 connected to brake operating linkage (not shown) and connected through a worm 5 and worm-wheel 3 to a splined brake-actuating cam-shaft. The worm-shaft 7 is rotatable, to take up brake clearance, through the clutch 9, 21 by a gear sector 27 pivoted by a cam (30, Fig. 2, not shown), deflected by the passage of an element (33) on a ratchet-wheel moved in steps when brake clearance is excessive by the relative motion between the housing 1 and a lever 42 connected with lost motion to the stationary structure. Motion of the gear sector causes clutch member 21 to rotate, riding over the teeth of member 9 and stressing spring 25, the latter returning the member 21 on brake release, as the worm and worm-wheel unlock, to rotate member 9 and the worm to take up slack. Members 9 and 21 may be separated by pulling on cover 17 to overcome spring 11. The worm-shaft 7 may then be rotated manually to adjust the clearance. In a second embodiment (Figs. 5-7, not shown) the element 33 on the ratchet wheel rocks a lever 50 which engages a further lever (53) connected directly to clutch member 21. In a third embodiment (Figs. 8, 9, not shown) the ratchet is operated on the application stroke of the brake by a lever having two pawls, the ratchet carrying a cam which lifts a rack member (127) engaging a sector on the clutch member 21.