| 摘要 |
992,832. Luffing tower cranes. KAPITALVERWALTUNGSGESELLSCHAFT KARL PESCHKE. Nov. 7, 1963 [Nov. 8, 1962], No. 43927/63. Heading B8B. A cable 18, Fig. 1, moves a trolley 5 along the jib 4 of a tower crane and also luffs the jib. The cable passes from the trolley over a pulley 22, Fig. 2, at the tip of the jib, over a guide pulley 31<SP>1</SP>, to a block and tackle 11, 12 and round a winch drum 8. When the cable 18 is wound in the trolley first moves to the outer end of the jib where it is held by a latch 33. Further shortening of the cable luffs the jib upwards. A cable 23, Fig. 1, between pulley blocks 11, 12 determines the lowermost position of the jib. When this position is reached the trolley is released by a cable 19 which extends between the tower and a lever 25 on the latch 33. A spring 20 is included in the cable 19. The trolley moves towards the tower by gravity. A lifting cable 16 extends from the tip of the jib round a pulley 27 on the trolley, round a hook pulley 28 over a pulley 29 on the trolley, guide pulleys 15, 30 on the tower and round a winding drum 7. |
