| 摘要 |
A trailer unit 211 has parking brakes that are released when a supply of pressurised air in a line 213 from a shunting tractor 210 is connected and are applied automatically when the supply of pressurised air is disconnected. The trailer unit 211 has a radio receiver 215 for receiving a radio signal from a radio transmitter 214 on the tractor 210 when reverse gear is engaged to activate a back-up battery system on the trailer unit 211 that powers a switch responsive to sensor means for detecting an object in the path of the trailer unit 211 while reversing so as to disconnect the supply of pressurised air causing the parking brakes to be applied if an object is detected.
|
