GB614901A - Improvements relating to controlling apparatus for fluid pressure brakes - Google Patents

Abstract

614,901. Vehicle brakes. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. Aug. 13, 1946, No. 23977. Convention date, March 15, 1943. [Class 103 (i)] In variable leverage brake mechanism of the kind comprising " live " and " dead " levers 4 and 6, Fig. 1, interconnected by a tie-rod 10 and a second tie-rod 15 formed at one end with slots 17, 18 of unequal length receiving a pivot pin 19 on the lever 6, and change-over mechanism operable to displace the end of the second tie-rod so as to engage the pin 19 with one or other slot, the change-over mechanism includes a lost motion device and a spring in which energy is stored if the mechanism is operated when the brake rigging is stressed, this energy being utilized to effect subsequent displacement of the end of the tie-rod when the brakes are released. The change-over mechanisms shown in Fig. 1 comprises a link 29 pivoted at 30 to the tie-rod and coupled by a bellcrank lever 32, 33 and rod 35 to an arm 37 on a shaft 38 fitted with a handle 40. A toggle spring 39 is connected between the shaft and the rod and operates to retain the mechanism in one or other of its adjusted positions. In one form of the invention, Fig. 3, the pivot pin 30 is received in a slot 41 in the link 29, and a spring 42 is arranged between the tierod and a collar 44 on the link. In Fig. 4, the pin 30 engages a slot in the link 29, and a spring 51 (corresponding to the spring 39) is interposed between abutments on a pivoted sleeve 53 and a rod 49 which is slidable in the sleeve and pivoted at the point of connection 47 of the rod 35 and an arm 48 loosely mounted on the shaft 38. The latter carries an arm 55 adapted to engage with one or other of two shoulders 56, 57 formed on the arm 48. In Fig. 6, the slot in the link 29 is omitted and the rod 35 is connected to one end of a lever 58 loosely mounted on the shaft 38, the other end of the lever being pivoted to a piston 61 slidable against a spring 63 in a cylinder 64 which is pivoted to a pair of parallel levers 59 rigid on the shaft. The Specification as open to inspection under Sect. 91 (4) comprises also the subject-matter of Figs. 1-4 (Cancelled, not shown), in which the displacement of the end of the tie-rod is effected automatically by a fluid-pressure cylinder, and Figs. 12 and 13 (Cancelled, not shown), in which change-over mechanism similar to that of Fig. 6 is mounted directly on the brake lever 6. This subject-matter does not appear in the Specification as accepted.