Patent ID: 7299778
Filing Date: 2007-11-27
Classification: F01L

Abstract:
1. A switchable cam follower or a switchable support device for a valve train of an internal combustion engine, said cam follower or support element comprising two elements telescoped into each other and axially displaceable relative to each other, one of the two elements comprising a bore extending perpendicular to a longitudinal axis toward the other of the two elements and at least one piston being arranged in the bore to extend within the bore in an uncoupled state of the elements, said piston comprising on a portion of an outer peripheral surface, a stepped entraining surface that starts from a first front end of the piston facing the other element, and coupling being achieved by a displacement of the piston partially beyond a parting plane between the elements so that the entraining surface comes to bear against a flat counter surface of the other element, characterized in that, starting from the first front end of the piston, the entraining surface of the piston extends toward a second front end of the piston while tapering into a conical shape generally in a direction toward a longitudinal axis of the piston, and an edge region of the entraining surface on the first front end and at least a part of a length of the entraining surface is additionally provided with a cylindrical, outwards arched (with reference to a starting point of the radius (R)) contour that extends orthogonally to the longitudinal axis of the piston.