US Patent 7610887 Valve-deactivating hydraulic lifter having a contoured pin housing bottom surface

A valve-deactivation hydraulic valve lifter including a recessed face on the pin housing for making contact with the a crowned surface region of a roller follower. The lifter includes a pin housing that is slidably disposed within an axial bore in a lifter body. Pins for variably locking the pin housing to the lifter body may be disengaged to place the lifter in lost-motion mode by application of engine oil to the outer ends of the pins. A surface of the pin housing, preferably configured as a dished surface, is formed on the bottom end face of the pin housing that approaches the cam-following lifter roller for making contact with the roller follower so as to avoid contacting the roller follower's crowned surface region.