| 摘要 |
An improved scissors lift which includes a hydraulic mechanism, in the form of one or more hydraulic cylinder/piston units, mounted on scissors linkages in an essentially vertical position in appropriate cradles between two arm pairs of the linkages, at a position in which there is substantial movement at both ends of the hydraulic unit. The cylinder/piston hydraulic unit is so mounted to exert a thrust primarily in the direction of the load for all positions of the linkages, and to provide an essentially constant load/thrust/speed ratio for all positions of the linkages, and also to permit full extension of the linkages without excessive movement of the hydraulic piston. The arms of the scissors linkages are provided with ear-shaped brackets at each end which serve to displace the pivotal axes between the arms away from the horizontal axes of the respective arms so as to permit the arms to be folded down directly on top of one another when the lift is in its collapsed position. This construction not only permits the lift to be collapsed to a minimum height, as compared with the prior art lifts, but it also provides for a minimum stress at the pivot points of the arms when the linkage is in its lowermost position, since the weight of the platform is directly supported by the arms of the linkages along their entire lengths.
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