Hydraulic lash adjuster oil metering valve

Claim 1

In a hydraulic lash adjuster, a cylindrical outer dash pot body, a hollow plunger telescopically received in said outer dash pot body with one end of said plunger extending outward from said outer dash pot body, said one end terminating in a semi-spherical end having an axial extending passage means therethrough to the interior of said plunger, the interior of said plunger constituting a reservoir for supplying fluid to said outer dash pot body inwardly of said plunger and for delivery out through said passage and, a metering valve for controlling flow from the interior of said plunger outward through said passage, the improvement wherein said passage means includes a first bore portion extending from the outer surface of said semi-spherical end, a second bore portion of a smaller diameter than said first bore portion, said first bore portion and said second bore portion meeting coaxially with an intervening inclined shoulder providing a valve seat and, wherein said metering valve includes an annular head with a depending, hollow shank extending from one side thereof, said shank having a first shank portion next adjacent said head of a predetermined axial length greater than the axial length of said passage and having an outside diameter less than the inside diameter of said second bore portion to provide an oil metering passage between said first shank portion and the inside diameter of said second bore portion, said shank further having a second shank portion next adjacent the free end thereof, said second shank portion having a major outside diameter greater than the inside diameter of said second bore portion, said head being of a diameter larger than the outside diameter of said first portion of said shank, both the diameter of said head and said major outside diameter of said second shank portion being less than the diameter of said first bore portion.