| 摘要 |
1,139,978. Driver's valve. WESTINGHOUSE BRAKE & SIGNAL CO. Ltd. 13 June, 1967 [20 June, 1966], No. 27450/66. Heading F2F. In a spring-applied braking system including a fluid control circuit incorporating a selflapping valve, the self-lapping valve is operable by a cam arrangement which comprises locking means to lock the valve in the " brake applied " position and release means by which the cam arrangement can be released from locking the valve. The self-lapping valve comprises a cap 3 rotatable about axis 4 by means of handle 6 on the innermost end of which there is a pin 7 engaging a bore 8 in extension 9 of a first face cam 10, cam 10 being free to rotate with handle 10. A second face cam 11 in contact with cam 10 is held in the valve body 2 so that it cannot rotate about axis 4, the cams being resiliently biased together by a spring 13. A pin 14 is provided concentric with axis 4 and located slidably in the first cam 10, its end abutting an extension 15 of cam 15: movement of pin downwards parting the two cam profiles 16, 17 via spring 13 and piston 20 against the force of spring 23. The movement of pin 14 is limited by a further pin 14a. On the cam profile 16 there is a projection 18, Fig. 2, which engages with a recess 19 on the cam profile 17 of earn 11 when the brakes are in the fully applied position: when it is desired to release the brakes pin 14 must first be depressed to release the handle, by separating the cam faces sufficiently for cam surfaces 31 to engage when the handle is rotated. |
