Patent ID: 6945204
Filing Date: 2005-09-20
Classification: F01L

Abstract:
1. A valve actuator assembly for an engine comprising: a movable engine valve; a movable finger for contact with said engine valve; a rotatable cam for contact with said finger; a finger-support element assembly for contact with said finger comprising a housing, a first piston and a second piston disposed in said housing, said first piston and said second piston being axially aligned and independently movable in the same direction to provide full lift of said engine valve in an activated mode and lost motion of said engine valve in a de-activated mode; and wherein said first piston and said housing have a first radial clearance to control leak-down of high-pressure fluid supporting said first piston in an engine valve fully-active mode and said second piston and said housing have a second radial clearance to enable high-speed reciprocating motion of said second piston when said engine valve is not fully active, said second radial clearance being greater than said first radial clearance.