| 摘要 |
The lifting appliance has a jib (16) which is mounted on a support (12) in such a way as to be pivotable at least about a horizontal axis (17). To produce a force moment which balances the load moment at a certain inclination of the jib (16), a working cylinder (28) is provided whose working pressure is kept constant by a control unit (37) at all inclinations of the jib (16). This working cylinder (28) is connected in an articulated manner to the jib (16) and the support (12) at such well-chosen locations (31, 32) that the difference between load moment and force moment, which difference is caused during the pivoting of the jib, can be coped with manually by one operator. In order to adapt the working pressure in the working cylinder (28) to the respective load, the jib (16) is connected to the load suspension means (23) in such a way as to be movable upwards relative to the load suspension means (23) against a restoring force. This relative movement controls the control unit for setting the working pressure, adapted to the load, in the working cylinder (28). <IMAGE>
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