Patent ID: 6698817
Filing Date: 2004-03-02
Classification: B60J,F15B

Abstract:
In combination with a vehicle having an open top container, a variable rate covering system comprising: a pair of arms pivotally supported on the vehicle for movement between a first position and a second position; a rolling cover member connected between the vehicle and said arms, said cover member being disposed in a stowed condition in said first position exposing the open top of the container and in an extended condition in said second position covering the open top of the container; a hydraulic cylinder including a piston member operatively connected between said vehicle and each of said arms; and a fluid control assembly for delivering fluid to actuating chambers in said cylinders at opposed ends of said piston member for effecting an actuating stroke between an extended position and a retracted position and thereby moving said arms between said first position and said second position, first and second metering ring members carried in outer grooves on opposite ends of said piston member, each of said metering ring members having a diametral clearance with said groove and including radial slots formed in opposed axial surfaces thereof, said slots and said grooves providing restricted flow paths past said metering ring members during terminal portions of the stroke; a first sealing member and a second sealing member carried on a center portion of the piston member; a first fluid port in said cylinder partially obstructed by said first sealing member in said first position and a second fluid port in said cylinder partially obstructed by said second sealing member in said second position for restricting the flow rates to said actuating chambers during initial movement of said piston member between said extended and retracted positions.