Patent ID: 8490590

Claim:
A hydraulic adjuster for use with an internal combustion engine including: a cylindrical body having an open upper end, a closed bottom, and a second oil supply hole formed in the sidewall of the cylindrical body; and a plunger having an upper end serving as a plunging end, a sidewall having a first oil supply hole, and a high pressure chamber at the bottom of the plunger, the plunger being slidable on the inner wall of the body and provided with a reservoir communicated with an external oil supply line via the first oil supply hole of the plunger and via the second oil supply hole of the body and provided with a small hole for connecting the reservoir with the high pressure chamber, the high pressure chamber including a check ball adapted to open and close the small hole in response to a rise and a fall of the oil pressure in the high pressure chamber and including a spring for urging the plunger in the longitudinal direction of the plunger, the hydraulic lash adjuster characterized in that: the first and second oil supply holes are communicated with each other through an annular communication passage formed between the sidewalls of the plunger and the body; a check valve is provided in the annular communication passage in association with the second oil supply hole, the check valve adapted to open/close the second oil supply hole in accordance with the pressure of the oil supplied from an external oil supply line to the second oil supply hole; the annular communication passage is a circumferential groove formed in the inner surface of the sidewall of the body; the check valve is a belt-shaped leaf spring adapted to abut against the bottom face of the circumferential groove; and the check valve has an engagement protrusion for engaging the second oil supply hole for axial and circumferential positioning of the leaf spring in association with the second oil supply hole.