US Patent 7982143 Electric switch having an annular stationary contact

An electric switch including a stationary contact that is annular. The switch comprises a gastight enclosure, a conductor bar of axis (D), a stationary contact presenting a contact zone of substantially annular shape, a switch element, e.g. on the conductor bar, that is movable in the axial direction of the axis (D) between a first position in which it penetrates in part into the stationary contact to establish electrical contact between the conductor bar and the stationary contact, and a second position in which it interrupts said contact. The stationary contact, which is in the form of a ring that is circular or elongate, such as elliptical, surrounds the conductor bar, at least in part.