Patent ID: 6139454
Filing Date: 2000-10-31
Classification: F16H

Abstract:
A hydraulic tensioner comprising:a housing having a bore;a hollow piston slidably received within said bore and defining a fluid chamber with said bore, said piston having an upper end, said piston upper end having an aperture, said piston aperture forming a conduit for fluid communication from said fluid chamber to the outside of said piston;a piston spring located within said hollow piston, said piston spring biasing said piston in a protruding direction from said bore;a check valve provided between the fluid chamber and a source of pressurized fluid, said check valve permitting fluid flow into said fluid chamber while restricting flow in the reverse direction;a plastic cap member located at the upper end of said piston above said piston aperture, said plastic cap member having an aperture to permit the flow of fluid through said plastic cap member, said plastic cap member being axially translatable between a first closed position in which fluid is prevented from exiting through said plastic cap aperture, and a second open position in which fluid is permitted to flow through said plastic cap aperture and out of said plastic cap member.