| 摘要 |
A jacking apparatus for selectively moving a load in either of opposite directions such as vertically upwardly and downwardly. The apparatus is adapted for use in a wide range of building constructions, such as those using slipforms, wherein heavy loads are positioned by the jacking apparatus. The apparatus includes gripping elements having portions engaging elongated structural elements for effecting desired movement of the jacking apparatus in moving the load. The gripping elements are mounted on parallelogram linkage supports for maintained parallel relationship to the longitudinal extent of the elongated structural element with which they are selectively engaged. A control device is carried by the respective upper and lower gripping devices for effecting automatic control of the gripping elements in effecting a lowering of the apparatus when desired. The control is arranged to effect a sequential releasing and gripping of the elongated structural element by the gripping elements as an incident of individual movement of the respective gripping devices.
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