| 摘要 |
996,674. Collapsible tower cranes. RICHIER. April 24, 1963 [April 25, 1962], No. 16223/63. Heading B8B. A collapsible tower crane mounted on a wheeled chassis 1, Fig. 1, has a telescopic tower 4, 5 pivoted about a horizontal axis 13 to a jib which has three sections 8, 9, 10, Fig. 3, pivoted together by vertical pins 14, 15 so that the crane can be completed folded for transport as shown in Fig. 1 without removing any part of it. The centre section 8 of the jib overhangs the tower so that the trolley 12 and counterweight 11 can be accommodated. To erect the crane the jib is extended and released from the tower so that the counterweight can cause the jib to tilt, Fig. 5, restrained by the lifting hook 17. The counterweight is allowed to run to the end of the jib and rest on planks 20 on the ground by means of wheels 19. The tower is raised by conventional means with the help of struts 7. Extra sections 23, Fig. 10, may be added to the top of the tower and ballast 24 may be provided. Outriggers 3 carry jacks 16 bearing road or rail wheels. The wheels 2 at both ends of the chassis 1 may be steerable. The counterweight may run either on or in the jib instead of below as shown. With this modification, the centre section of the jib may be shorter as no overhang is necessary. |
