| 摘要 |
<p>An apparatus for increasing the available hook raising and lowering distance is attached to a crane (10) or other lifting structure having a boom (20) and at least one lifting tackle (35) utilizing at least one lifting line connected to a prime mover (74). The apparatus utilizes a support means (56) attached to the crane boom substantially at the connection point of an existing upper tackle. A fixed, lower gripper platform (90) is suspended from the support means and has at least one linear winch grip (160) mounted thereon. A movable, upper gripper platform (140) is connected to at least one lifting line (70) associated with the lifting tackle. The upper gripper platform has at least one linear winch grip (160) mounted thereon. The upper gripper platform is also adapted to reciprocate between the lower gripper platform and the upper tackle in response to the prime mover drawing in or paying out the lifting line.</p> |
