GB868793A - Improvements in and relating to air or gas blast electric circuit-breakers - Google Patents

Abstract

868,793. Gas-blast switches. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Oct. 2, 1957 [July 12, 1956], No. 21598/56. Class 38 (5). An air or gas blast switch has a tubular insulating member 9 extending through an opening in a wall 8 of an enclosure, the member constituting a discharge duet from the contact chamber of the switch and housing a lead-in conductor 16 extending from a terminal 12 at the discharge end of the member 9 to a contact of the switch. In Fig. 1 the switch comprises fixed and moving contacts 1, 3 housed in a chamber 5, 6 and operated by a piston within a cylinder 4. The fixed contact 1 is electrically connected with a metal tube 14 which extends into the lower end of the lead-in conductor 16, the tubes 14, 16 being interconnected by a copper strap 18. In a further arrangement the lower end of the member 9 provides the contact chamber, the fixed contact being mounted on the metal tube 16, Fig. 2 (not shown). In either case the space between the member 9 and the tube 16 may be filled by a solid filling with condenser layers or by an oil or compound filling. Instead of a metal lead-in tube a conductor bar or strip may be provided, the discharge from the switch flowing around the conductor. In this last case a conductive or semi-conductive layer may be provided on the inner surface of the member 9. Specifications 817,782 and 868,792 are referred to.