Patent ID: 8007384

Claim:
A hydraulic tensioner comprising: a housing having a plunger-accommodating hole formed therein and extending along an axis, said hole having an opening and a bottom spaced from the opening; a plunger slidably protruding from the plunger-accommodating hole, through said opening, in a protruding direction, and, with said hole, defining a high pressure oil chamber, said plunger being movable from a fully retracted position to a fully extended position; a coil spring disposed within the high pressure oil chamber, said spring being wound around said axis, being in compression, and biasing the plunger in said protruding direction; a check valve incorporated into the housing for allowing oil to flow into the high pressure oil chamber and blocking flow of oil out of the high pressure oil chamber; and a bar at least a part of which is located within said coil spring, the bar reducing the volume of the high pressure oil chamber; in which the coil spring has first and second opposite ends, and comprises a coil-shaped intermediate part of disposed between said ends, in which a clearance is provided between said coil-shaped intermediate part of the spring and the bar, said clearance allowing relative axial movement of the spring and the bar; and in which a part of the coil spring adjacent said first end of said first and second opposite ends is positioned to block passage of said bar out of the coil spring, whereby the bar is prevented from dropping out of the coil spring during assembly of the tensioner.