Patent ID: 6053486
Filing Date: 2000-04-25
Classification: F16F

Abstract:
A damper cylinder for reducing a rate of movement of two spaced apart objects, connected at opposed ends of the cylinder, away from or toward each other with the cylinder in a vertical orientation, which comprises:(a) a housing having a first end and a second end with at least one side wall therebetween forming a chamber containing a liquid and a gas in the first end of the housing which is uppermost, the second end having an opening and the first end connected to one of the objects;(b) a rod member having a first end and a second end and slidably and sealably mounted through the opening in the second end of the housing such that the first end of the rod member extends into the housing and the second end of the rod member is connected to a second of the objects;(c) a piston member slidably and sealably positioned on the side wall in the chamber of the housing and having opposed ends mounted on the first end of the rod member, the piston member having at least two orifices extending parallel to the rod member through the piston member;(d) two first elastomeric disc seals, smaller in diameter than the piston member, each mounted on one of the opposed ends of the piston member, wherein when a rate of movement of the rod member and piston member in the housing exceeds a predetermined rate, a force of the fluid in the housing on the seal causes one of the first seals to move such as to close at least one orifice of the at least two orifices in the piston member to reduce the rate of movement of the rod member and the piston member;(e) a valve means spaced from the piston member at a limit of travel of the piston member, the valve member having at least two orifices extending parallel to the rod member through the valve means; and(f) a second elastomeric disc seal mounted on the valve means facing the piston means and smaller in diameter than the valve means, wherein as the piston member is moved towards the valve means at a predetermined rate, the second disc means closes at least one of the at least two orifices in the valve means and wherein the orifices remaining open when the piston member and rod member are moved away from the valve means.