Compressed-gas circuit interrupter having insulated contacts

A compressed-gas circuit interrupter comprising a first pair of separable contacts, operating means for moving the contacts between open and closed positions, each contact being tubular and having an electrically conducting insert comprised of arc erosion-resistant material at the upstream open end thereof, a tubular electrically insulating liner on the inner surface thereof, the inserts of both contacts being in electrical contact in the closed position, each liner being recessed from the open end of the contact to provide an unlined tubular surface end portion, each liner having a tubular zone of reduced diameter downstream of the gas flow from said insert, the tubular zone of reduced diameter being smaller than the diameter of the insert, the tubular zone being within an electrically insulating material, and gas supply means for directing a flow of compressed gas into the tubular contacts when the contacts are opened to effect elongation of an arc extending between the unlined tubular surface end portions, whereby the arc is extended in opposite directions within the tubular insulating liners.