| 摘要 |
1,227,659. Self-erecting mobile tower cranes. R. B. CADILLON. 17 April, 1969 [23 April, 1968], No. 19756/69. Heading B8B. [Also in Division E2] A tower crane comprises a foldable telescopic mast and a foldable jib hinged to the top of the mast. As shown in Fig. 1A the mast 4 is pivoted at 11 by a detachable pin to a slideway 12 on chassis 1 and can be erected by extending a pair of hydraulic jacks 13 pivotally connected at 14 to the chassis 1 and at 15 to the bottom member of the mast 4. From the position shown in Fig. 1A if the detachable pin is removed extension of the jacks 13 slides the mast horizontally to its transporting position where it can be locked at 16 by means of a pin. Fig. 2A shows an embodiment with a mast 4 in an intermediate position. Jacks 17 are connected between pivots 18 on the mast 4 and 23 on a support 24. Contraction of the jacks 17 from the position shown slides the mast 4 in the direction of arrow F4 to its transport position, Fig. 2B (not shown). Alternatively, if pin 26 is removed and the jacks 17 contracted the support 24 may be slid to the ghosted position shown and fixed by a pin 25. If the mast 4 is now pivoted to an extension la of the chassis 1 at 20, extension of the jacks 17 erects the mast 4, a crutch (not shown) being folded up from the chassis 1 to assist in supporting the erected mast. In the embodiment shown in Fig. 3B a mast 4 is arranged to be erected from its transport position, Fig. 3A (not shown), by extension of jacks 44 attached to the chassis 1 at 45 and driving rods 47 pivotally connected to the mast 4 adjacent a hinge 46 arranged at the base of the mast 4. Arms 48 pivotally interconnect the chassis 1 at 49 and the mast 4 at 50 so that erection of the mast 4 is combined with a sliding action in the direction of arrow F. This embodiment may be modified to provide hoisting of the jib (not shown) after the mast is erected, Figs. 4, 5 (not shown). |
