Hydraulic lash adjustor in a valve operating mechanism

Claim 1

In an improved hydraulic lash adjustor in a valve operating mechanism of the type including a cylinder, a plunger slidably fitted into said cylinder, a hydraulic chamber defined between both the cylinder and the plunger, a hydraulic oil reservoir chamber formed in the plunger, said hydraulic oil reservoir chamber being communicated with the hydraulic chamber by way of a valve bore which is formed through a bottom portion provided on a lower side of said plunger, a check valve mounted on said valve bore so as to open when hydraulic pressure in the hydraulic chamber decreases and close when it increases, a valve cage secured to the plunger to accommodate therein said check valve, a cylindrical portion extending downwardly from the bottom portion of said plunger, an annular engagement groove formed around the inner peripheral surface of said cylindrical portion, and a resilient member adapted to bias said plunger so as to project outwardly of the cylinder, wherein said valve cage comprises a cap-shaped main body and a flange portion integrally extending radially outward from the peripheral end part of said main body, said flange portion being firmly held in place between the bottom portion, of the plunger, and a caulking ring fitted into said annular engagement groove, the improvement wherein a lower side wall surface of the annular engagement groove is formed as a tapered face descending radially inwardly.