Self-contained lash adjuster with diaphragm-type seal

Claim 1

A self-contained lash adjuster including a generally cylindrical cup-shaped follower, a lash adjuster cartridge assembly, a spacer mounting said cartridge assembly within said follower, said cartridge assembly including a reciprocally movable body and a plunger within said body, a high pressure chamber defined between said plunger and body, a plunger passage opening into said high pressure chamber, a check valve controlling flow through said plunger passages, and a diaphragm-type seal attached at its outer periphery to an interior wall of said follower and attached at its inner periphery to the movable body, an annular recess formed in the interior wall of said follower, the outer periphery of said diaphragm seal having an enlarger area positioned within said recess, with said spacer holding the outer periphery of said diaphragm seal and the enlarged area thereof in said recess, said diaphragm seal having a radial distance between its inner and outer peripheries on the order of about 1.5 to 2 times the radial distance between said body and follower interior wall spanned by said diaphragm, said diaphragm-type seal and follower interior wall defining a fluid reservoir, passage means connecting said reservoir with said cartridge assembly, movement of said body toward the plunger moving fluid from said cartridge assembly to said reservoir and causing a stretching of said diaphragm-type seal.