Abstract: A gas circuit breaker having a main fixed element and a main movable element capable of contacting and moving apart from each other, a fixed contact provided on the main fixed element side, a movable contact provided on the main movable element side and capable of contacting and moving apart form the fixed contact, an insulation nozzle provided on the main movable element side to surround the contacts, a hollow nozzle provided inside the movable contact, a cylinder, a puffer cylinder and a fixed piston provided on the main movable element. The insulating nozzle serves to compress a gas in a puffer chamber defined by the puffer cylinder and a fixed piston and to guide the gas to the gap between the contacts disconnected.

Abstract: A puffer type gas circuit breaker having at least one pair of a stationary contact and a movable contact capable of being separated from each other, a pressure producing section including a puffer cylinder and a puffer piston. The puffer cylinder is connected to the movable contact and serves to compress an arc extinguishing gas blown to an arc generated between the contacts at the time of current breaking. The breaker also has a cover surrounding the movable contact, an insulated nozzle extending from the puffer cylinder and surrounding the cover and the stationary contact to form a flow passage through which the compressed gas is supplied from the puffer cylinder to the generated arc, and a flow straightening member provided in said flow passage. The flow straightening member extends from the puffer cylinder and is mounted on the cover, and the flow passage has an expanded section having a gas flow sectional area larger than that of the section of the flow passage upstream of the expanded section.

Abstract: A gas circuit breaker comprising a pair of contactors contact portions of which are separable relatively from each other, an insulating nozzle of an electrically insulating material surrounding the contact portions of said contactors so as to guide a flow of gas, and a puffer chamber for compressing the gas in conjunction with a separating operation of the contact portions so as to supply it under guidance of the insulating nozzle, the gas from the puffer chamber being exhausted through exhaust passages passing through a hollow portion of the one contactor located within the insulating nozzle, wherein the exhaust passages are formed between the puffer chamber and the one contactor, and the gas circuit breaker further comprises block means serving to close during an initial stage of the separating operation and open afterward exhaust ports formed at ends of the exhaust passages located on the downstream side of the gas flow.

Abstract: A gas circuit breaker includes a pair of separable contact portions, a nozzle of an electrically insulating material surrounding the contact portions to guide a flow of gas, and a buffer chamber for compressing the gas upon a separating operation of the contact portions so as to supply the gas under the guidance of the insulating nozzle. The gas from the puffer chamber is exhausted through exhaust passages passing through a hollow portion of a movable one of the contactors. The exhaust passages are formed between the puffer chamber and the movable contactor. A blocking arrangement, during initial stage of the separating operation, closes the exhaust ports of the exhaust passages and subsequently opens the exhaust ports located on a downstream side of the gas flow. The blocking arrangement, of an electrically insulating material, is divided along an axial direction of the gas circuit breaker.

Abstract: A switch provided with a negative pressure chamber which is actuated in association with the separating operation of a movable contact. The negative pressure chamber is connected to a means for supplying a fluid to the negative pressure chamber so as to suppress the negative pressure in the negative pressure chamber during the initial stage of the separaating operation of the movable contact.

Abstract: In a circuit breaker in which an interrupting device, a resistor device and a capacitor device are connected in parallel, a shield device is arranged to shield the interrupting device and the resistor device and comprises a first shield for shielding the stationary main contact and stationary resistor contact and a second shield for shielding the movable main contact and movable resistor contact. Each of the first shield and the second shield comprises a large shield portion and a small shield portion, and the small shield portions are arranged between the large shield portions. The small shield portion terminates in the vicinity of the top of the main contact and of the top of the resistor contact. The small shield portion comprises wide portions situated substantially in the direction of an axis joining centers of the main contact and resistor contact and narrow portions situated substantially in the direction perpendicular to the axis.

Abstract: Breaker units (3, 4) of three-phases are enclosed in a common container (25). The three-phase breaker units and lead conductors (27a, 28a) connected to both ends of the breaker units are arranged on imaginary straight lines that are in parallel each other nearly passing through vertexes of an equilateral triangle. A common operation unit (7) for driving the three-phase breaker units is accommodated outside the container (25) and juxtaposed at a position opposed to one side (28b-28c) of the equilateral triangle. A zero-phase sequence current transformer (ZCT) is provided surrounding the lead conductors of three phases outside the container.

Abstract: Disclosed is a switch operation monitoring apparatus for quickly and accurately detecting an abnormal operation of an actuating mechanism actuating a switch such as a power circuit breaker. A normal characteristic stroke of a moving part of the actuating mechanism is previously calculated on the basis of an interrupting current waveform, an environmental gas pressure and an actuating fluid pressure while taking into account the structure of the switch so as to use the calculated characteristic stroke as a reference stroke, and this reference stroke is compared with an actually measured characteristic stroke to decide whether the operation of the actuating mechanism actuating the switch is normal or abnormal.

Abstract: Disclosed is a gas circuit breaker of resistance breaking type, which comprises a main breaking unit and a resistance contact mechanism electrically connected in parallel with the main breaking unit for resistively cutting off current. With the opening action of the main breaking unit, a spring used for opening the resistance contact mechanism is energized and the energized force of the spring is released by a releasing mechanism after the current in the main breaking unit is cut off, thereby to act as a drive force to open the resistance contact means.

Abstract: A grounded support tank type gas circuit breaker comprising a cylindrical tank maintained at ground potential and filled with an arc-extinguishing gas, and a breaking unit disposed within the tank with its central axis extending along the axis of the tank. In the circuit breaker, a capacitor unit is disposed within the tank in axially aligned relation with the breaking unit with its axis extending along an extension of the central axis of the breaking unit, so that the capacitor unit can be easily incorporated in the circuit breaker by merely increasing the axial length of the tank.

Abstract: An electromagnetic puffer type gas circuit breaker comprises two opposing puffer type gas circuit breaking units mounted on midway support means, actuating means for driving the circuit breaking units, an electromagnetic actuating unit drivingly coupled to the actuating means, and current transfer mechanism for transferring and applying the interrupting current to the electromagnetic actuating unit during a circuit breaking operation. The current transfer mechanism is located, in operative connection to the actuating means, at a point above the midway support means and in a spaced relation to the electromagnetic actuating unit. The contact surface area of the current-conducting path portion leading to the transfer mechanism is a fraction of that of another current-conducting path portion for the passage of most of the rated current. These features provide ease of inspection and replacement of the current transfer mechanism and reduces the operating force requirement of the breaker.

Abstract: In a magnetic puffer type gas circuit breaker including an electromagnetic coil through which a current to be interrupted flows during the breaking operation, and an electromagnetic repulsive member which produces an electromagnetic repulsive force in cooperation with the electromagnetic coil and drives movable parts of a breaking portion of the apparatus, the electromagnetic repulsive member is so arranged that the electromagnetic neutral position of the electromagnetic repulsive member within the electromagnetic coil at the time when the breaking portion has been closed deviates on the closing side with respect to the electromagnetic center of the electromagnetic coil.

Abstract: Two puffer type circuit breaking units are symmetrically disposed with respect to a bracket interposed therebetween. Linking means are mounted in the bracket, and one end of the linking means is connected to movable parts of the puffer type circuit breaking units and the other end is connected to operating means through an electrically insulated operating rod. An electromagnetic coil is disposed in the bracket and an electromagnetic repulsive member is electromagnetically connected to the electromagnetic coil to produce an electromagnetic repulsive force. During the breaking operation, current transferring means mounted in the puffer type breaking units are actuated to apply an electric current to the electromagnetic coil, and an electromagnetic repulsive force is imposed on the electromagnetic repulsive member to actuate the movable parts of the puffer type breaking units together with the operating means, whereby the breaking of a large current is made possible.

Abstract: A circuit breaker having a pair of circuit breaking units electrically insulated from ground by supporting means of electrical insulator, an actuator disposed on ground, and an actuating force transmission path including a single actuating rod of electrical insulator for connecting the actuator to the movable contacts in the circuit breaking units. In the circuit breaker, an electromagnetic actuating unit is disposed between the supporting means of electrical insulator and the circuit breaking units in electrically insulated relation from the circuit breaking units.