| 摘要 |
A safety device for a flexible load- supporting cable for a downwardly hanging telescopic boom, comprises a guide pulley (4) for the cable (3), mounted for movement in response to tension in the cable, a wedge (8) mounted for movement relative to a co-operating wedge-trap (12) in response to movement of the pulley (4), at least one safety strap (6) mounted on a spring-tensioned reel (10), passing between the wedge (8) and the wedge-trap (12) and connected at one end to the boom, such that, in the presence of normal working tension in the cable the wedge (8) is held free of the wedge- trap by the effect of the working tension on the pulley (4) and that on loss of normal working tension in the cable, the safety strap (6) is engaged between the wedge (8) and the wedge-trap (12). <IMAGE> |
