Patent ID: 8235017

Claim:
A switchable component of a valve train of an internal combustion engine, comprising a housing having a borehole in which an inner element is held so that it can move telescopically, at least one coupling piston guided by an anti-rotation locking device is located in a radial borehole in the inner element in a decoupled state, the coupling piston includes a section that is flattened in some areas on one axial side starting from an outer end thereof, and the housing has a window or an annular groove/an annular-groove segment with a complementary engagement surface against which, in a coupled state, the coupling piston can be displaced with the flattened section when passing through a cam base circle and an edge of the coupling piston between the outer end and the flattened section is provided with a bevel that is a surface section of an ellipsoid whose longitudinal axis extends parallel to the flattened section.