| 摘要 |
<p>The scissor lift has two parallel sets of legs (12, 14). Each set has one end of an outer leg (12) pivoted on a base (10) and the other end slideable on the elevating platform (22) One end of the inner leg (24) of each set is pivotally connected to the platform (12) while the other end slides on the base (10). The mid portion of the legs (12, 24) are pivotally connected on a pin (32) which also supports a crank (34) which can rotate about 90 DEG between a first generally horizontal position in which the actuated end (36, 42) of the crank (34) is eccentric to an imaginary line connecting the pivot pin (32) and the pivot (41) of a ram (40) which actuates the end of the crank. Initial actuation of the crank 90 DEG raises the pivot pin (32) and the actuated end (36, 42) of the crank (34) to increase the mechanical advantage of the ram (40). The angle of the ram (40) now has adequate uplift to be as effective as the prior art while requiring about 1/2 the storage height. A stop bar (43) is pivoted on the pivot pin (42) and has a free end (54) or tail slideable along the base (10) as the pivot pin (32) rises. A plurality of spaced stops (56) are welded on the base and are engaged by the stop bar (43) as the lift is lowered due to pressure loss or failure to actuate a control cable to lift the lock bar (43) over the stops (56).</p> |
