| 摘要 |
<p>The pole's lower end is pivoted (8), on a horizontal transverse axis, on a turret (6) rotatably mounted about a vertical axis (5), and supported on a metal base (4) on the front roof (2) of the vehicle (1). The pole's vertical inclination is controlled over a range 0-45 deg. approx. by a (preferably) double-acting pneumatic actuator (32) connected between the turret top (42) and a clamp (36) on the pole (10). Opt., a single-acting cylinder, opposed by coil springs, is used. Through rack-and-pinion gear, another double-acting actuator can rotate the turret through a limited angle. The pole is articulated (14) near its upper end, allowing the spring-loaded tip section (16), carrying the current collecting shoe (19), to swing up about 15 deg., against a stop, if the shoe escapes from the overhead catenary conductor (20). A sensor detects this condition. Shoe derailment initiates an immediaet alarm (142) on the driver's dashboard control unit (37) and causes the pole angle actuator to lower the pole to the horizontal or storage position (12a). A rapid descent below catenary level precedes a slower final retraction. During the latter phase, the other actuator turns the turret to give fore-and-aft alignment. The driver controls angle and orientation manually through a hand-held remote unit plugged into the vehicle exterior. A regulator operated by a sensing cam (7) adjusts the elevating actuator to maintain constant contact pressure (F) as pole angle varies.</p> |
