| 摘要 |
1,187,319. Electric control system for brakes. GENERAL SIGNAL CORP. 20 Nov., 1968 [24 Nov., 1967], No. 55107/68. Heading F2F. In an over-speed controlled automatic brake system, for e.g. a locomotive, the over-speed control may be operated by wheel-slip during starting. To overcome this the OVERSPEED DETECTOR is by-passed during starting by a short-period timer. As shown an R.C. timing circuit R1C1 is charged over a " throttle off " contact 16 and a train-motion-relay contact T.M.R. (to prevent operation of the by-pass circuit by throttle closure when the train is running). The timing circuit feeds transistors T1 . . . T4 to energize a cycling relay TC until the charge on C1 leaks away. Relay TC cycles by disconnecting transistor T1 from C1 over its back contact 19. While TC cycles relay TCP is held up by the charging and discharging of capacitors C2, C3 over contacts 20, 21 of TC. With TCP up contact 26 maintains the electropneumatic brake valve EPV closed even if the overspeed relay OS opens. |
