| 摘要 |
<p>An apparatus of the present invention is used for movable objects upwardly and downwardly relative to a fixed surface. The apparatus includes a lifting device presented by a pair of blocks movable relative one and the other. A carriage device is supported by the blocks. The carriage device is connected to object to be lifted relative the fixed surface. An actuator is connected to the blocks. As the actuator moves the blocks relative one and the other, the blocks move above the carriage device relative the fixed surface at various distances lift and lower the objects.</p> |
