| 摘要 |
<p>A self-locking grab is designed for lifting cube shaped objects such as packing cases without need of hooks or slings. The grab consists of two parallel beams (1) with pivot bolts at each end which support L-shaped levers (6, 7). The lower ends of these levers (6, 7) have pads (14, 15) which press against the load. The upper ends of the levers are attached to a ring (29) fixed to a rod (27) which slides in a tube (28) fixed to the beams. As the ring is raised by the crane the levers swing inwards to grip the load. An electric magnetic device is fitted to hold the levers apart when not lifting a load.</p> |
