摘要 |
<p>The retarder is installed adjacent a railway track for reducing the speed of a wagon rolling along the track and additionally has the capability of boosting the speed of a wagon. The retarder includes a hydraulic unit (1) having a portion (12) adapted to be deflected out of the path of a wheel of the wagon when directly or indirectly engaged by the wheel before returning to its original position. The unit (1) has adjustable hydraulic damping capable of resisting such deflection to retard the wagon, and a wagon speed responder (9) for adjusting the hydraulic damping of the unit to retard a wagon travelling at high speed. The retarder further includes a regenerative source (2) of hydraulic fluid under pressure connected to the unit (1) by a selector valve (4) such that, when a wagon passes over the unit travelling at high speed, the resultant retarding operation of the unit results in charging of the regenerative source (2) with hydraulic fluid whereas, when a wagon subsequently passes over the unit travelling at low speed, hydraulic fluid under pressure is supplied to the unit from the regenerative source (2) to cause boosting of the speed of the wagon by forced return displacement of the portion (12) in direct or indirect engagement with a wheel of the wagon.</p> |