| 摘要 |
<p>A swing-around side stowable jib (23) for crane booms (20) is safely supported at all times during movement from its use position to its stowed position, and vice versa. In the short transitional movement of the jib following its release from its nose assembly (21) pivot (25) and immediately prior to re-engaging this pivot (25), the jib (23) is always securely held by a strongly biased safety latch (50-58) in supportive engagement with a side mounting assembly (26) located between the nose assembly pivot (25) and a second mounting assembly (27) on the boom rearwardly of the first mounting assembly (26). The safety latch (50-58) at proper times is easily released by operation of a hand lever (83) near ground level. Locks (113, 85) for the safety latch and its release lever are also provided. The safety latch is swiveled (47,48) and biased (59) to meet the swing-around jib (23, 24) squarely as it approaches the stowed position.</p> |
