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

A valve-deactivating hydraulic lifter for selectively coupling the rotary motion of a cam lobe to the reciprocal motion of a valve pushrod in an internal combustion engine, comprising:

• a) a lifter body having a roller for following an eccentric surface of said cam lobe, said roller having a central region for contacting said cam lobe and chamfered portions outboard of said central region, said lifter body having a first axial bore and an axial locking surface formed in a wall of said first axial bore;
• b) a pin housing slidably disposed in said first axial bore and having a transverse bore therethrough and having a second axial bore;
• c) at least one locking pin slidably disposed in said pin housing transverse bore, said at least one locking pin having an outer end for selectively engaging said axial locking surface to lock said pin housing to said lifter body
• wherein said pin housing has an axial surface facing the central region of said roller, wherein said axial surface of said pin housing is defined by a pin housing surface and a shouldered ridge, wherein said shouldered ridge is configured to make contact with said chamfered portions and wherein said axial surface of said pin housing is configured to avoid contacting said central region.

An internal combustion engine having a valve train comprising a valve-deactivating hydraulic lifter for selectively coupling the rotary motion of a cam lobe to the reciprocal motion of a valve, wherein said lifter includes

• a lifter body having a roller for following an eccentric surface of said cam lobe, said roller having a central region for contacting said cam lobe, said lifter body having a first axial bore and an axial locking surface formed in a wall of said first axial bore,
• a pin housing slidably disposed in said first axial bore and having a transverse bore therethrough and having a second axial bore,
• at least one locking pin slidably disposed in said transverse bore, said at least one locking pin having an outer end for selectively engaging said axial locking surface to lock said pin housing to said lifter body,
• wherein said pin housing has an axial surface facing the central region of said roller, wherein said axial surface of said pin housing has a radius of curvature less than infinity, and wherein said axial surface of said pin housing is in configured to avoid contacting said central region.