Patent GB-499663-A (GB)
Title: Improvements in electric circuit breakers of the impulse type
IPC: H01H33/92
Filed: 1937-07-26
Abstract: 499,663. Liquid - blast switches. UPTON, A., PAILIN, G., and FERGUSON PAILIN, Ltd. July 26, 1937, No. 20635. [Class 38 (v)] An impulse circuit-breaker comprises in combination at least one pair of co-operating contacts, power means such as a source of previously-stored energy for positively mechanically separating said contacts, tripping means controlling the release of said power means, a member of insulating material having passages for the co-operating contacts and inlet and outlet ducts adapted to direct insulating liquid across the arc path between the separating contacts, a piston pump, power means (which may be the same as, or additional to, the aforesaid power means) adapted to operate the piston of said pump upon operation of said tripping means, a free and unrestricted insulating tube directly connecting the pump cylinder with the inlet duct of said member of insulating material, and a tank or chamber which houses at least the contacts, member of insulating material, and insulating tube and which is adapted to hold a body of insulating liquid sufficient to flood at least the three members last mentioned. The pump piston may be driven by a loaded spring or compressed air in a manner per se known. The fixed and moving butt contacts 2, 3 are separable in an insulating member 1 having a narrow outlet 6 which produces a high-speed flow across and beyond the arc and may contain one or more arc-splitters 7. Member 1 may be a solid block or built up of plates after the manner of cross-jet explosion pots, and leads by an inlet passage 5 into an insulating tube 4 which leads in turn to an elbow 8 and oilcylinder 9 containing a piston 10. The crosssection of tube 4 is half that of the cylinder 9. The elbow 8 carries the cylinder 10 and is formed integral with, or carried on, a support 41, 42. A bracket 44 attached to the lead-in 35 supports a collar 39 carrying a mounting 38 by means of which the lead-in 35 is connected to contact 2. The movable contact 3 slides in a resilient sleeve 30 and is connected by insulating member 29 to a sliding cross-head 27 linked at 26 to a lever 24, which is connected with lost-motion at 21, 23 to a shaft 14 to which the pump-piston 10 is connected. Shaft 14 is operated through a shaft 15 by an air-piston 18 and cylinder 19. Non-return valves are provided in the piston 10, or elsewhere, to enable the cylinder 9 to refill with oil, the level of which is shown. The pump 9, 10 may alternatively be located outside the oil-tank. The parts are shown with the contacts about to open, the piston 10 having already begun its stroke, as permitted by the lost-motion connection 21, 23. Fig. 2 shows a suitable form for the contact 2 and the arrangement of the mounting 38 and collar 39 which is to form a stress-distributer correspondingly with the flared end of a collar 40. The contact 2 is carried on a stem 47 operating in a tubular casing 48, a stop nut 50 and helical spring 49 being provided. The tube 4 may be connected to the cylinder 9 by an elbow 8 instead of directly, as shown. In Fig. 3 (not shown), the above arrangement is adapted to an insulating member 1 having a vertical exhaust.