| 摘要 |
<p>1,074,279. Telescopic masts. RICHIER. April 12, 1966 [April 12, 1965], No. 16043/66. Heading B8B. A telescopic mast, suitable for a tower crane, is extended by raising an inner member 3 with respect to an outer member 2, this causes pins 15 to abut stops 6 thereby turning latch members 14 to median positions from which they are turned in the same direction by springs 17 to positions in which they abut stops 19, Fig. 4 (not shown). With the members 14 in this position the inner part of the mast may be lowered until the members 14 rest on abutments 4 attached to the outer member of the mast. To retract the inner member 3 it is raised until the latch members 14 abut further stops 5, these latter turn the latches 14 anti-clockwise to median positions from which the springs 17 return them to the original position shown in Fig. 1. The inner member 3 may now be lowered. When the pins 15 strike the stops 6 the latter, which are spring-loaded, are pushed downwards so that the movement of the latches is not impeded.</p> |
