Abstract: A circuit breaker utilizes a plurality of vacuum interrupters immersed in oil. A cross-bar with electrically conductive sections completes a series electrical circuit through the circuit breaker and actuates operating mechanisms, to close the contacts of the vacuum interrupters when in the raised position as the cross-bar is lowered, the contacts of the vacuum interrupters are opened by impact forces before isolation gaps which fill with oil are created in the series electrical circuit. Various arrangements of the vacuum interrupters are disclosed for uprating existing oil circuit breakers.

Abstract: A circuit breaker characterized by first and second main contacts and first and second arcing contacts. The first main and arcing contacts are mounted on a first contact carrying arm. The second arcing contacts are mounted on a second contact carrying arm. The second main contacts are mounted on a third contact arm. The first contact carrying arm is mounted on a first pivot and the second and third contact carrying arms are mounted on a second pivot. A spring for biasing the second main contact against the first main contact and in the closed position. A second spring for biasing the second arcing contact against the first arcing contact until after the first and second main contact separate.

Abstract: A metal-clad, compressed gas-blast circuit-breaker having a gas-filled housing and an interrupter unit supported in the housing by a hollow post insulator. The circuit-breaker has a shifting linkage with at least one insulating drive rod, the shifting linkage transmitting the switching motion from a driving mechanism to a movable switching contact. In order to reduce the overall axial length of the circuit-breaker, the hollow post insulator comprising only insulating material, is penetrated only by the insulating drive rod and has, for fixing to the housing, on an end area facing away from the interrupter unit, on an outside surface, a premolded flanged ring mounted set back axially from the edge and being adapted to the bearing ring of the housing. The described circuit-breaker is esepcially suited for application in gas-insulated, metal-clad, high-voltage switching stations.

Abstract: A molded case circuit breaker enclosure cooperates with the current-limiting line strap to prevent the egress of ionized gases. The gases are generated by a high temperature arc which occurs when the contacts are separated under short circuit conditions.

Abstract: A charge transfer device in which, during manufacture, a first upper electrode does not entirely cover a space separating two lower electrodes, and the zone thus left free is filled by a conductive material of the same type as the first upper electrode part. The method according to the invention allows simple manufacture without restrictions as to the positioning of the masks for manufacturing the electrodes, and allows manufacture without covering of the upper and lower electrodes, thereby allowing to reduce the stray capacities.

Abstract: A switch chamber for a vacuum switch including a housing composed of a ceramic insulating tube, a contact pin mounting a stationary contact within the housing and a terminating cover connecting the insulating tube with the contact pin in a vacuum-tight manner. Another contact is positioned adjacent the stationary contact and is movable in the axial direction of the insulating tube. A bellows forms a vacuum-tight connection between the movable contact and the housing. In the switched-on position the movable contact contacts the stationary contact under action of a contact spring force and shock stresses are transferred to the housing by the terminating cover which includes an elastically deformable section and a plastically deformable section.

Abstract: A Fusible electric switch is herein described for increased ratings within industrial electrical distribution circuits by the provision of an arc exhaust gas controller. The arc gas controller cools and deionizes the arc gases that are generated upon separation of the switch contacts and exhausts the gases in a predetermined direction outside the switch enclosure. Fuse pullers are arranged at one end of each of the switch fuses to facilitate both installation and removal of the fuses.

Abstract: Current interrupters for high voltage networks are disclosed which sever the post-zero arc plasma, connecting a pair of arc terminating electrodes, near an upstream wall electrode and displace the severed plasma with a high dielectric strength gas, gaining dielectric strength faster than the transient network voltage recovers across the lengthening plasma discontinuity. Use of a high enthalpy dielectric displacement gas, created at the time of load or fault current interruption, makes plasma severing and displacement possible. High enthalpy displacement gas mixtures are preferably produced by combustion of solid propellants and/or ablation of solids rich in hydrogen.

Abstract: A draw out interlock comprises an elongated interlock member which is coupled to the manual trip mechanism of a circuit breaker. The interlock member is springed bias to an extended position where it projects through the back wall of the circuit, but is retained in a retracted position by the surface against which the circuit breaker is mounted. As the circuit breaker is removed from the mounting surface, the interlock member extends actuating the manual trip mechanism and interrupting current before the circuit breaker becomes disconnected from the protected conductor to prevent arcing at the disconnects.

Abstract: A current limiting circuit breaker having a pair of separable contacts closely spaced for electrodynamic repulsion upon the occurrence of a short circuit overload condition utilizes an arc chute to cool and extinguish the arc that occurs when the contacts become separated. The arc chute contains a plurality of metal arc plates supported by side plates which also assist in cooling and extinguishing the arc. The side plates are formed from a suspension of wollastonite fibers within a melamine resin matrix. The wollastonite provides good mechanical strength and temperature-resistance properties while the melamine provides a continuous source of arc-quenching gaseous molecular compounds.

Abstract: A control circuit for a circuit interrupting switch having a non-stored energy operator reduces the time period between a switch command and a change of the switch contacts. The time period is reduced by prearming the mechanical operating linkage after each switch operation. By prearming the mechanical operating linkage, the linkage has less distance to travel and hence the time period between a switch command and a change in the switch contacts is greatly reduced.

Abstract: A molded case circuit breaker is provided with a line conductor having a U-shaped slot defining a pair of depending leg conducting portions and a peninsula portion. The U-shaped slot is adapted to receive a slot motor and also causes the current of the peninsula portion to flow in a direction opposite the direction of current flow in the movable contact arm to cause the contacts to be blown open during relatively high level overcurrent conditions. The peninsula portion is tapered outwardly, toward the base of the peninsula to increase the overall cross-sectional area of the conductor to minimize temperature rise. The tapered peninsula portion still allows a slot motor to be received in the U-shaped slot.

Abstract: A replacement vacuum operated circuit breaker assembly for voltage distribution switchgear fits into switchgear cubicles that are shaped to accommodate air magnetic circuit breaker assemblies such as the Allis Chalmers 5KV series. The replacement breaker assembly frame configuration and adjustable contact poles allow the replacement assembly to be installed in the original switchgear without expensive modifications to the cubicles.

Abstract: A self-expansion electrical circuit breaker includes an arc extinguishing chamber of variable volume by repulsion of a piston by the pressure of the gas in the extinguishing chamber. A semi-stationary contact is securedly united to the piston so as to increase the separation distance of the contacts at the same time as the volume of the extinguishing chamber increases.

Abstract: A high tension circuit breaker containing a dielectric gas under pressure, the circuit breaker being of the type comprising at least one interrupting chamber comprising an insulating envelope filled with said gas and containing a fixed assembly including a fixed main contact (2) and a fixed arcing contact (4), and a moving assembly including a moving main contact (7) and a moving arcing contact (5), the interrupting chamber also containing a pair of secondary contacts and a blast cylinder opening out into a blast nozzle. The circuit breaker further includes first means (37, 38,104) for limiting the maximum separation distance between the secondary contacts to a value which is less than the maximum separation distance between the arcing contacts, and second means (60, 101) for preventing any arcs being struck during closure.

Abstract: The present invention provides a circuit breaker in which the blast cylinder is delimited by a first cylinder (5) constituting the moving arcing contact, a second cylinder (7) constituting the fixed main contact, and a first piston (14) sliding between said first and second cylinders, said first piston being urged by a spring (17) to come into abutment against a part (16A) fixed to the fixed assembly, the cylinder (5) constituting the moving arcing contact and a tube (16) connected to the fixed assembly and coaxial with said cylinder together delimiting, on the other side of the piston (14) closing the blast cylinder, a variable volume (35, 35B) closed at one end by said first piston (14) and at its other end by an annular end piston (42) connected to said first cylinder (5) and sliding along said tube (16), said volume enclosing said secondary contacts, a first secondary contact (30) being fixed to said tube (16) and the second secondary contact (31) being entrained by said first cylinder (5).

Abstract: A current limiter comprises an extinguishing chamber 16 of small volume, in which there are housed a pair of contacts 28, 30 and an insulating shield 40, capable of moving to an active position inserted between the contacts 28, 30, and of subdividing the chamber 16 into two parts each of which contains one of the contacts 28, 30. The movement of the insulating shield 40 to the inserted position between the contacts 28, 30 is favored by the action of a piston 48 subjected to the pressure prevailing in the extinguishing chamber 16.

Abstract: A vacuum breaker contact produced according to the coating step of forming a metal coated layer comprising at least one metal selected from the group consisting of Cu, Ag, Ni, Sn, In, Fe and alloys thereof on at least a part of the surface of the contact substrate having a predetermined shape to a thickness of 10 .mu.m or less, and the diffusion step of having a part of said metal coated layer diffused into said contact substrate.

Abstract: A vacuum circuit interrupter includes a vapor condensing shield formed of a porous structure of copper including a grain size inhibitor, such as boron, and a gettering metal, such as titanium or zirconium, in order to achieve enhanced levels of gas adsorption capability.

Abstract: The present invention relates to a puffer type circuit breaker having a high voltage and large capacity, which is provided with an insulating nozzle for blowing a arc-extinguishing gas of high pressure generated by separating a movable contactor from a fixed contactor. The fixed contactor has a larger diameter portion formed on the base portion thereof and a smaller diameter portion formed at the tip end thereof, and the insulating portion has a first throat portion adjusted by the smaller diameter portion and a second throat portion located at the downstream side of the first throat portion and adjusted by the larger diameter portion, thereby allowing the gas inlet portion to be formed by the diameter difference between the first throat portion and the smaller diameter portion which is in such manner that the second throat portion is adjusted by the larger diameter portion.