Passenger lift movable at variable speeds
AssigneeRicon Corporation
InventorStanton D. Saucier
Life of this patent
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Abstract
A hydraulic drive passenger lift with distinct lifting "up and down" (loading, unloading) and "fold-unfold" (storage) motion patterns, includes a flow control structure that accommodates various hydraulic flows, somewhat unrestricted for "up-and-down" movement, and different for "fold" and "unfold" movements. The flow control structure includes multiple paths between a source and an actuator, with control for selecting the appropriate path to yield predetermined flow rates. A solenoid driven spool valve and a biased movable orifice member select the desired path. Accordingly, while the flow is substantially unrestricted during "up-and-down" movement, it is somewhat restricted for reduced speed during the "unfold" movement and is more restricted during the power-driven "fold" movement.
Claims10
A multiple motion-pattern hydraulic lift as for moving passengers in relation to a vehicle, said lift comprising:
- a platform mechanism structure for carrying a passenger and adapted to be affixed to said vehicle for movement through phases of distinct storage and passenger bearing motion patterns, said platform mechanism structure adapted to lie in a substantially horizontal plane and move along a substantially vertical plane through said passenger bearing motion pattern, between a lower position outside said vehicle and a raised position substantially level with a floor of said vehicle, said platform mechanism further adapted to swing from said raised position through swing up and swing down phases of said storage motion pattern;
- hydraulic apparatus connected to said platform mechanism structure for actuating said platform mechanism structure;
- and
- a hydraulic flow control structure connected in a circuit with said hydraulic apparatus to control said motion patterns and including, passage structure defining a plurality of passages, valve means for controlling flow in said passages, and a moving orifice member in at least one of said passages for attenuating flow in one direction through said one passage during at least said swing up phase of said storage motion pattern.
Dependencies are inferred from the claim text.