Patent ID: 7104232

Claim:
A deactivation hydraulic valve lifter, comprising: an elongate lifter body having a substantially cylindrical wall, including an inner wall surface, said wall defining at least one annular pin chamber therein, said lifter body having a first end configured for engaging a cam of an engine; an elongate pin housing including a pin housing wall and pin housing body portion, said pin housing wall having an outer surface, said pin housing body portion defining a radially directed pin bore therethrough, said pin housing being substantially concentrically disposed within said inner wall surface of said lifter body such that at least a portion of said outer surface of said pin housing wall is adjacent to at least a portion of said wall of said lifter body; a deactivation pin assembly disposed at least partially within said pin bore, said deactivation pin assembly including two pin members, said pin members biased radially outward relative to each other, at least a portion of each said pin member being disposed within a corresponding one of said at least one annular pin chamber to thereby couple said lifter body to said pin housing, said pin members being configured for moving toward each other when said at least one annular pin chamber is pressurized, thereby retracting said pin members from within a corresponding one of said at least one annular pin chamber and decoupling said lifter body from said pin housing; and a drain aperture defined by said pin housing body portion, said drain aperture extending from said pin bore to an outside surface of said pin housing body portion.