Patent ID: 7982567

Claim:
An electromagnetic actuator for a switch apparatus, comprising a fixed part, a moving part and an excitation coil, the fixed part comprising a ferromagnetic yoke and a magnetized assembly of at least one magnet fixedly mounted on the yoke, the magnetized assembly extending in a direction substantially parallel to an axis of movement of the moving part, the moving part comprising a ferromagnetic element comprising a first air-gap surface for forming a magnetic air-gap of variable thickness from the ferromagnetic yoke, and a second air-gap surface for forming a residual magnetic air-gap of substantially constant thickness from the fixed part, said second air-gap surface being substantially parallel to the axis of movement of the moving part, the excitation coil enabling the position and speed of the moving part to be controlled by an electric control current, wherein the magnetized assembly faces the second air-gap surface so that, whatever the position of the moving part, the residual magnetic air-gap is always between the second air-gap surface of the ferromagnetic element of the moving part and a corresponding air-gap surface of the magnetized assembly, and the at least one magnet of the magnetized assembly is on a face of the ferromagnetic yoke and extends substantially over the entire dimension of said face parallel to the axis of movement.