Hydraulic lash adjuster oil metering means

Claim 1

In a hydraulic lash adjuster for an internal combustion engine having a body with an open upper end, a plunger reciprocal within said body, said plunger having a central cavity defining an oil reservoir; oil inlet means communicating with said reservoir; a closure element in said open end of said body forming a fulcrum for a rocker arm; flow passageway means from said reservoir to said rocker arm for lubricating said fulcrum and rocker arm; and means for metering the flow of oil through said flow passageway means; the improvement comprising: said flow passageway means comprising a bore through said closure element communicating between the upper and lower end of said closure element; a plate means in the form of a thin flat disc positioned in a space formed between said plunger and closure element below said lower end portion of said closure element and above said reservoir and urged by the oil pressure in said reservoir against said lower end portion of said closure element; said plate means having at least a portion of its diameter less than the diameter of the adjacent wall of the plunger to permit oil flow from said reservoir around the outer circumference of said plate means when said plate is urged against said end portion and a slot means formed in said lower end portion of said closure element and extending radially from said bore to essentially the annular interface formed between said plunger and closure element, the interior of said plunger including a shoulder forming a seat which limits the downward movement of said plate means, the slotted lower end of said closure element extending downwardly into said plunger and spaced above said seat a distance greater than the thickness of said plate means, said slot and plate means forming a restricted flow passageway from said reservoir to the bore of said closure element; said restricted flow passageway metering the rate of oil flow through said adjuster to said rocker arm.