Abstract: A contact device has a pair of flanges which extend inward in the radial direction from both ends of an annular shield, and a plurality of contact pieces which are arrayed in the circumferential direction in a space formed by the shield and the pair of flanges, the axial direction thereof being matched to the parallel direction with the axial center of the shield. Contact sections are provided on the outer peripheral surfaces at both ends of each contact piece. The contact device also has a plurality of rod-shaped elastic members disposed in the circumferential direction on the flanges, each of the elastic members being cantilever-fixed to the flange in such a manner that one end thereof is secured to an inner edge surface of the flange and the other end thereof is allowed to extend along the axial center of the shield into a space formed by the shield and the pair of flanges. The rod-shaped elastic members elastically support the contact pieces to restrict the contact pressure of the contact sections.

Abstract: A gas-insulated disconnector includes a movable contact disposed above a fixed contact within a housing filled with an insulating gas. The movable contact is electrically coupled to an upper support member through a finger-type sliding contact 3 which is dip-shaped and is fixed to the support member at the upper end thereof and is in sliding contact with the interior surface of the cup-shaped movable contact. An operating rod connecting the movable contact to a link mechanism is slidably supported by a support cylinder extending within the movable contact. Thus small metal particles generated by the abrasion of the contact surfaces at the side of the movable contact is contained within the movable contact and do not drift into the gas-insulated gap.

Abstract: A gas insulated switchgear includes main bus bars disposed vertically and branch circuit units connected to and spread horizontally from the main bus bars, the branch circuit units each comprising disconnecting switches, circuit breakers, current transformers, bushings or cable heads. Both the improvement of reliability and an outstanding economic effect can be attained by a simple structure.

Abstract: A gas-insulated electric device comprising an electric conductor disposed in a sealed vessel filled with an insulating gas, the conductor being supported by a solid insulating member. The insulating gas is a nitrilic fluorocarbon compound or a mixture of a nitrilic fluorocarbon compound and SF.sub.6. In this device, the dielectric strength is increased. Accordingly, the size of the device can be decreased.

Abstract: The disclosed switching system comprises a circuit breaker, a grounding device, a locking device for the grounding device, and a fluid filled axially movable cylinder connected at one end to the circuit breaker and including at the other end a spring loaded piston connected to the locking device. When the circuit breaker is opened upon the occurrence of a fault on a mating electric path, the cylinder and then an internal piston is moved to release the locking device to ground the electric path through the closure of the grounding device which is then opened. After about one second determined by a first flow passageway for throttling a flow of fluid between two compartments of the cylinder disposed on both sides of the piston and a second flow passageway with a check valve extending between those compartments, the piston and the cylinder are returned back to their original positions to lock the grounding device in its open position by the locking device.

Abstract: An improved electrical bushing uses a refrigerant to provide cooling of both the bushing and the electrical apparatus to which the bushing is connected. The refrigerant vaporizes inside the hollow conductor of the bushing at the hot contact end, and flows to a heat dissipating device connected to the terminal end of the conductor. A liquid collecting plate collects the refrigerant which has liquefied in the heat dissipating device, and a slender tube inside the conductor transports the liquid refrigerant back to the contact end without the refrigerant contacting the intermediate portion of the conductor.

Abstract: A gas-insulated transmission line is formed of a plurality of outer sheath sections joined together lengthwise, with a conductor disposed therein. A two leg insulating spacer supports the conductor within the sheath sections, and axially extending grooves on said sheath sections receive the ends of the insulating spacer.