| 摘要 |
1,272,127. Workman - supporting booms. KLOCKNER - HUMBOLDT - DEUTZ A.G. 22 Aug., 1969 [4 Sept., 1968], No. 41990/69. Heading B8H. [Also in Division E1] A motor vehicle having a turntable ladder 1, 2 and a working cage 9 which can be suspended from the top of the ladder, has a change-over switch 11 mounted on the turntable 2 and operable by removing the cage from supports 10 on the turntable to change the operating range of the ladder which is determined by an arrangement including an operation range indicator. In one embodiment an indicator 14 (Fig. 3) incorporates contact plates 16 and 17 which are contacted by a contact blade 15 at different ladder extensions for a given elevation to cut off ladder movement when a relay 20, operated by the switch, is inoperative or operative respectively. The operating range is thus more limited when the cage is removed from the turntable, whether or not the cage is used on the ladder. |
