| 摘要 |
A load lifting jack comprising a support member, a screw shaft rotatably located within the support member, a lifting arm supported at the substantially middle portion by a link and connected at its end to a threaded nut engaged with the screw, the nut being adapted to be displaced along the length of the screw shaft in order to raise or lower the lifting arm, the link being pivotally connected to the lifting arm at one end and having means for engaging the other end with any selected one of a plurality of recesses provided on the support member so that engagement thereof easily and quickly locates the lifting arm in its desired position. A rotatable jack base may be provided for lifting inclined loads to prevent undesired lateral movement of the load lifting jack.
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