Abstract: The invention relates toa circuit breaker, preferably for high or medium voltage. The movable conact of each breaker pole is connected, via mechanical means for transmitting movement, to a movable part of an electric motor (6). The movable contact and the means for transmitting movement are arranged in a gas-tight apparatus chamber (31) surrounded by a gas-tight apparatus housing (9) of insulating material such as porcelain. In accordance with the invention the motor (6) is arranged entirely in the apparatus chamber (31). The invention also relates to an electric plant provided with the breaker claimed, uses of the breaker claimed and a method of breaking electric current in which the breaker claimed is used.

Abstract: The invention relates to an electric circuit breaker. The circuit breaker comprises at least one mobile contact with operating means (2) for operating the same. An electric motor (6) is arranged for driving the operating means (2). The motor (6) is powered from a current source (50) via a current converter (40). According to the invention, the motor (6) and/or current converter (40) are greatly under-dimensioned in relation to the output the current converter is designed to deliver. This is possible because the operating duration is so brief. Under-dimensioning results in extensive cost-savings. The invention also relates to an electric plant equipped with such a circuit breaker. The invention further relates to the use of such a circuit breaker and a method for breaking electric current in the corresponding fashion.

Abstract: On both sides of a metal switching chamber, the novel vacuum switch tubes are respectively provided with two ceramic insulators (63, 64; 65, 66) which have the same diameter (D2). Axially interspaced (Al) cylindrical vapor shields (70, 73; 71, 74) are fixed to the wing parts of said components. The easy to produce low-volume structure means that is possible to control operating voltages of more than 60 kV.

Abstract: A vacuum switch container, a vacuum switch, a method of producing the vacuum switch container and a method of producing the vacuum switch are provided. Ceramic granulated powers are used to fill a space of a cylindrical shape defined by an outer hard metal mold having an inner diameter of 120 mm and a center hard metal pin having an outer diameter of 108 mm. A pressure of 1000 kg/cm2 is applied in an axis direction relative to the cylindrical shape by using lower and upper cylindrical punches, from both the top and bottom of the space, to produce a green compact. Next, the green compact is fired in open air at 1600° C. to produce a cylindrical ceramic fired body. Each of the end surfaces of the ceramic fired body are then ground and the ground surface is metalized. Ni plating is applied to the metalized surface, thereby forming an electroconductive layer thereon to complete the vacuum switch container.

Abstract: A conductive heat sink is electrically interposed between a fuse and a switching apparatus within a watertight case of a network protector. The heat sink is advantageously configured to conduct current between the switching apparatus and the fuse. During operation, the skin effect causes the electricity conducted by the heat sink to flow primarily through the outer regions of the heat sink, thereby resulting in the generation of heat at the outer regions of the heat sink due to electrical resistance. The heat sink includes a core from which a plurality of fins extend. The fins conduct and convect heat away from the outer regions of the heat sink, which reduces the temperature thereof and correspondingly increases the conductivity of the outer regions of the heat sink.

Abstract: A vacuum switch comprises a first vacuum container containing therein a circuit breaker, a second vacuum container containing therein the first vacuum container and grounded, and a third vacuum container connected to the second vacuum container, containing therein a disconnecting switch and an earth device and grounded. The second and third vacuum containers are isolated in vacuum from the first vacuum container, and the second vacuum container is electrically insulated from the first vacuum container. The second vacuum container contains an insulator fixed to a conductor connected to the circuit breaker and a movable rod partially disposed out of the vacuum containers and operating the circuit breaker to open and close. The disconnecting switch, circuit breaker and the insulator are arranged in a line. A vacuum switchgear comprises the above-mentioned vacuum switches of the number corresponding to three phases and necessary components, each being contained in a metal box.

Abstract: A vacuum exhaust element of a vacuum switch has an ordinary withstand voltage because the vacuum vessel and power source element are grounded, therefore not requiring the high voltage to be taken into consideration. This way, the vacuum exhaust element is miniaturized and it is safe for a worker to touch the vacuum vessel and the vacuum exhaust element when performing maintenance and/or inspection.

Abstract: Methods and apparatus for facilitating current transmission through a circuit breaker are described. In an exemplary embodiment of the apparatus, a coupler that includes a copper conductive ring having an inner annular wall is provided. The coupler is electrically coupled to the line terminal. A bore extends through the ring, and the bore is sized so that the shaft can extend therethrough. A plurality of copper bristles extend radially inward from the ring inner annular wall, and the bristles are in electrical contact with the conductive ring. The bristles also are in electrical contact with shaft when shaft extends through ring bore. At least some bristles extend sufficiently radially inward from the ring inner wall so that free ends of at least some bristles are in electrical contact with the shaft when the shaft extends through the bore.

Abstract: The invention relates to switchgear with switching devices that can be controlled by magnetic drive devices, especially vacuum circuit breakers, wherein the switching devices are arranged by blocks in a housing in correspondence with the number of phases to be switched, said housing enclosing the switching devices on three sides and said devices being releasably fixed by screws in the housing by a top and a bottom contact connection piece. The switching devices (VS) have separate housings that are formed by pole shells (PS) arranged as a mirror image of each other and the top and bottom contact connecting piece (KAo, KAu) form a top and a bottom cooling body (KKo, KKu) which are releasably fixed between separately arranged vacuum circuit breaker fixing webs (VB . . . ) of the pole shells (PS), wherein the top cooling body (KKo) is fitted in the peripheral area of the switching devices (VS) with ventilation slots (LS . . .

Abstract: A vacuum switch includes a pair of windmill-shaped electrodes within a vacuum tube and including windmill portions and contact portions. Each of the windmill-shaped electrodes is arranged such that a component of a magnetic flux parallel to a contact surface and serving as an arc driving force with respect to a range of 0.5 mm from the contacting surface contacting the contacting portion of a leg portion of an arc has a magnetic flux density equal to or larger than 0.01 tesla with respect to an electric current of 1 kA, at any point on the contacting surface. The ratio of an inner diameter Di of the contact portion to an outer diameter D of the windmill-shaped electrodes is equal to or greater than 0.

Abstract: A third electrode (8A) is soldered, via a support fitting (9) onto the inner surface of a support part (1a) which projects into the intermediate part of the inner surface of an insulation tube (1A). An arc generated between the fixed-side contact (5A) and the movable-side contact (5B) when the switch is opened is led from the outer periphery of the fixed-side contact (5A) via the third electrode (8A) to the movable-side contact (5B), in a so-called two-point switch, and the dielectric breakdown probability is thus reduced, particularly at low voltages. The third electrode may have its outer periphery exposed from the insulation tube and be used as one electrode when conditioning is carried out. By the use of this structure, the present invention is capable of meeting the demands for environmental protection and insulation reliability.

Abstract: A vacuum valve includes a vacuum vessel having an interior portion sealed by a fixed-end end plate and a moving-end end plate disposed at first and second end portions, respectively, of a cylindrical electrically-insulating tube, a fixed electrode rod secured to the fixed-end end plate, a fixed electrode being disposed on an end portion of the fixed electrode rod, a movable electrode rod, a movable electrode capable of contacting and separating from the fixed electrode being disposed on an end portion of the movable electrode rod, and an electrode shield secured to the electrically-insulating tube and enveloping the fixed electrode and the movable electrode, the electrode shield preventing an inner wall surface of the electrically-insulating tube from being polluted by a metallic vapor generated by the fixed electrode and the movable electrode during electric-current interruption, a recess portion being formed in a central portion of only one of either a contact surface of the movable electrode or a contact s

Abstract: The inventive electric contact point of a vacuum valve is made of a sintered alloy containing a heat-resistant metal and a high-conductivity metal. The contact point has at least three slit grooves which extend from the central region to the peripheral region of the contact point, and is soldered to an electrode rod which is connected to the contact point. The contact point includes at least three radially extending vane type contact point members each made of a sintered alloy containing a heat-resistant metal and a high-conductivity metal, and soldered to the electrode rod.

Abstract: A vacuum circuit breaker including a metal tank containing insulation gas with a branched portion connecting a first bushing containing a vacuum valve, and another branched portion connecting a second bushing containing a first conductor, and a branched conductor in the metal tank connecting the vacuum valve and the first conductor.

Abstract: A metal-ceramic composite (a vacuum switch unit 50) having a metal member 13 having a tubular portion 13b, and a cylindrical ceramic member 55. The metal-ceramic composite (the vacuum switch unit 50) has a structure in which an end face of the tubular portion 13b of the metal member 13 is butt joined via a joint metal layer 15 to an end face 55a of the cylindrical ceramic member 55 in an edge sealed manner. In order to provide a metal-ceramic composite having a high joint strength which is less likely to cause defects such as cuts or cracks at the joint, the joint metal layer 15 and the ceramic member 55 contact each other at an annular region of W (mm) in average width which extends circumferentially about the end face 55a of the ceramic member 55. Furthermore, W and D have respective values which satisfy D≧30 {circle over (1)}; and (1/60)×D≦W≦(D/30)+3.1 {circle over (2)} where D (mm) is an outer diameter of the ceramic member.

Abstract: The invention relates to switchgear assemblies having switching devices arranged in housings whose contact bolts can be deflected in a straight line and can be controlled by a magnetic drive device and are guided axially and radially by means of concentrically arranged slotted guides. The housings are formed by mutually opposite pole shells, and the slotted guides are each provided by rotating guides mounted at one end. The rotating guides each have a trapezoidal lever contour and are equipped with guide pins which extend outward and are mounted such that they can rotate in guide recesses in the mutually opposite pole shells. The rotating guides are each provided with a U-shaped bolt bearing in which a guide bolt is mounted. Switchgear assemblies such as this are used in the field of electrical power supply and distribution.

Abstract: The invention aims at providing a vacuum circuit-breaker, a vacuum valve used therein and electrodes for the vacuum valve, which can reduce the manufacturing cost while being of high performance and compact in size. The invention resides in a vacuum circuit-breaker, a vacuum valve and electrodes for the vacuum valve, which are characterized in that fixed and movable electrodes each comprise arc electrodes, whose entire surfaces, mutually facing each other, are made of an alloy containing a refractory metal and a highly conductive metal, and electrode rods of a highly conductive metal supporting the respective arc electrodes, and that each arc electrode and the mating electrode rod are integrally formed by means of solid-phase diffusion bonding.

Abstract: A vacuum switch container, a vacuum switch, a method of producing the vacuum switch container and a method of producing the vacuum switch are provided. Ceramic granulated powders are used to fill a space of a cylindrical shape defined by an outer hard metal mold having an inner diameter of 120 mm and a center hard metal pin having an outer diameter of 108 mm. A pressure of 1000 kg/cm2 is applied in an axial direction relative to the cylindrical shape by using lower and upper cylindrical punches, from both the top and bottom of the space, to produce a green compact. Next, the green compact is fired in open air at 1600° C. to produce a cylindrical ceramic fired body. Each of the end surfaces of the ceramic fired body are then ground and the ground surface is metalized. Ni plating is applied to the metalized surface, thereby forming an electroconductive layer thereon to complete the vacuum switch container.

Abstract: The flux density Bct is applied at the center area of the electrode. The flux density Bct is adjusted within the range A of 0.75 to 0.9 times greater than the axial flux density Bcr which gives the lowest arc voltage between the electrodes against each breaking current. The axial flux density monotonously increases from the center to the circumferential area of the electrode. Here, the radial position where the axial flux density Bcr which gives the lowest arc voltage Vmin is adjusted within the region B of 20% to 40% of the radius of the electrode. The axial flux density is made monotonously increase in an outer area from the region B and give the maximum value Bp in a circumferential area equal to or beyond 70% of the radius of the electrode. The maximum value Bp is adjusted within the range C of 1.4 to 2.4 times greater than the flux density Bct given at the electrode center.

Abstract: A metal-ceramic composite is provided in which a solder layer and a ceramic member are held in contact with each other at an annular area extending along an entire circumference of an axial end surface of the ceramicmeber and having an average width W (mm), and in which the average width W and an outer diameter D (mm) of the ceramic member satisfy D≧30 and (1/6)×D≧W≧(D/30)+2.6.

Abstract: A vacuum switching chamber is provided for power switches in the low-voltage range, and has compact design and a high switching capacity. A housing of the switching chamber includes plate-type current terminals, a cylindrical wall part that surrounds flat spiral petal contacts, an annular insulator and a bellows arranged concentrically thereto. The current terminal bolt of the movable spiral petal contact is seated on the associated plate-type current terminal.

Abstract: The tubular vapor shield of a vacuum interrupter is secured to the ceramic by a shield mount which includes a split ring seated in a circumferential groove formed in the inner surface of the ceramic. The tubular vapor shield is secured to the split ring by a connection which includes a circumferential flange brazed to the shield and a braze ring which is wedged in an annular gap between the flange and the vapor shield and which melts when heated in a vacuum oven to braze the split ring to the vapor shield and the flange. In another embodiment, the flange has a radial outward rim which seats on the split ring. In an additional embodiment, the connection between the split ring and the vapor shield includes a circumferential shield groove in the outer surface of the vapor shield in which the split ring is also seated and optionally secured by a braze.

Abstract: The single-phase circuit-breaker comprises at least one interrupting chamber formed by an insulating tube filled with an insulation gas, and it comprises at least one current transformer whose secondary is disposed in air around the primary at one end of the tube. The primary is at the high voltage electrical potential of the phase and is constituted by an annular metal support. The secondary is subjected to a high voltage electrical potential that is practically equal to the potential of the primary. The current transformer is thus integrated in the circuit-breaker, and the measurement electronics associated with the secondary can be located in air close to the secondary.

Abstract: A breaking module for an electrical switchgear apparatus comprises a vacuum cartridge comprising a body and a support frame of the cartridge. The cartridge is provided with a metal rod movable in translation and driving a movable contact. A collar both performs radial positioning of the body of the cartridge with respect to the frame and constitutes a guide sheath of the rod. For fitting, the collar can be opened so as to insert the rod radially therein. Once the body of the cartridge has been encircled, the collar is inserted radially in guide grooves of the frame.

Abstract: A switchgear apparatus comprises a vacuum cartridge one contact of which is fixedly secured to a metal rod protruding out from the cartridge. A flexible metallic electrical connector designed to electrically connect the rod to a busbar is provided, at one of its ends, with a bored hole in which one end of the rod is inserted. The joint between the flexible electrical connector and the rod is achieved by means of a braze implementing a metallic filler compound having a low melting temperature, so as not to damage the cartridge when the brazing operation is performed.

Abstract: A gas-filled switching apparatus has a gas-filled sealed container having a container body with a neck which surrounds an opening and a flange which extends outwards from the neck. A cover is disposed on the flange to cover the opening, and a gasket is disposed between the cover and the flange to form a seal around the opening. A plurality of clamps detachably secure the cover to the flange. Each clamp includes an adjustable pressing member exerting a clamping force on the cover and the flange.

Abstract: An object of the present invention is to provide a vacuum switch which secures safety of a worker at performing maintenance and inspection and is high in reliability, and to provide a vacuum switchgear using the vacuum switch.

Abstract: A vacuum interrupter for a vacuum breaker, by which melting on contact surface caused by are concentration when a large current is broken and the arc can be rapidly extinguished by forming a strong magnetic field in vertical direction same as the arc when electrodes are separated, comprises: a vacuum container; a stationary cylinder electrode fixed on upper part of the vacuum container so as to be sealed; a movable cylinder electrode disposed on lower part of the vacuum container so as to be moved in vertical direction; and a stationary contact assembly and a movable contact assembly respectively connected to the stationary cylinder electrode and to the movable cylinder electrode for inducing electric current to be rotated to one direction and forming a compounded vertical magnetic field.

Abstract: An object of the present invention is to provide vacuum switch suitable for a distribution and transformation system compatible between structural simplicity and reliability and a vacuum switchgear using the vacuum switch.

Abstract: The single-phase circuit-breaker comprises at least one interrupting chamber formed by an insulating tube filled with an insulation gas, and it comprises at least one current transformer whose secondary is disposed in air around the primary at one end of the tube. The primary is at the high voltage electrical potential of the phase and is constituted by an annular metal support. The secondary is subjected to a high voltage electrical potential that is practically equal to the potential of the primary. The current transformer is thus integrated in the circuit-breaker, and the measurement electronics associated with the secondary can be located in air close to the secondary.

Abstract: A hybrid gas insulation switchgear apparatus comprises an enclosure in which an insulating gas is sealed, a bushing unit provided for the enclosure, a breaker unit disposed inside the enclosure, a disconnector unit disposed inside the enclosure and including disconnectors to be connected electrically in series to both sides of the breaker unit, an earth switch unit disposed inside the enclosure and including earth switches disposed between the breaker unit and the disconnectors, respectively, the earth switches being provided with main pole side electrodes disposed on the side of the breaker unit, and a current transformer unit mounted to the enclosure. The bushing unit including bushings each having a conductor connected to an electrode in the disconnector on a side opposite to the breaker.

Abstract: A device for degassing and brazing preassembled vacuum interrupters in only one brazing operation includes a base plate having at least one brazing site which features an opening of the base plate for connecting a suction pump and a bell which covers the opening and can be put on the base plate and lifted off. The bell is surrounded on the outside by an excitation coil to which medium- or high-frequency energy can be applied. The device includes a medium- or high-frequency generator for the excitation coil and with a cylindrical tubular susceptor arranged inside the bell for receiving at least one preassembled vacuum interrupter.

Abstract: In order to provide a vacuum switch suitable for a distribution and transformation system compatible between structural simplicity and reliability and a vacuum switchgear using the vacuum switch, the vacuum switch comprises switching portions installed in a grounded vacuum container; and a breaker, a grounding switch and an isolator as things having the switching portions, wherein the vacuum container is divided into at least two chambers, and the switching portion of the breaker is disposed in one of the chambers and the switching portions of the grounding switch and the isolator are disposed in the other of the chambers through an insulation body.

Abstract: The present invention relates to a vacuum cartridge, in particular for an electrical protection apparatus such as a switch or circuit breaker, said cartridge comprising an enclosure of appreciably cylindrical shape closed by two end-plates, two contacts extending axially inside the enclosure, at least one of which contacts called the movable contact is connected to an operating mechanism and is slidingly mounted between a closed position of the contacts corresponding to a rest position of the apparatus and a position in which the arcing contacts are separated and form an electric arc between them, separation of the contacts resulting in breaking of the electrical circuit, and a means for producing an axial magnetic field for diffusion of the arc in the arc formation area. According to the invention, this cartridge comprises means for speeding up cooling of the contact material in liquid form flowing on the contact surface of said arcing contacts during breaking.

Abstract: A moving first electrical contact arrangement (K1) has a switching contact (P4) and a U-shaped arcing horn (R1) on the end face. A stationary second electrical contact arrangement (K2) has a switching contact (P1) and a U-shaped electrical conductor loop (R2) on the end face. The electrical conductor loop (R2) is composed in its U-shaped part, of a bimetallic strip, composed of steel (2) on the inside and copper (3) on the outside; two mutually opposite switching contacts (P2, P3) are provided adjacent to this, and an arcing horn (3′) is provided on the end face. When the electrical switch is closed, the first electrical contact arrangement (K1) is moved to the left in the opposite direction to an arrow (5), so that all four switching contacts (P1)-(P4) make a pressure contact with one another.

Abstract: A vacuum switch comprises a first vacuum container containing therein a circuit breaker, a second vacuum container containing therein the first vacuum container and grounded, and a third vacuum container connected to the second vacuum container, containing therein a disconnecting switch and an earth device and grounded. The second and third vacuum containers are isolated in vacuum from the first vacuum container, and the second vacuum container is electrically insulated from the first vacuum container. The second vacuum container contains an insulator fixed to a conductor connected to the circuit breaker and a movable rod partially disposed out of the vacuum containers and operating the circuit breaker to open and close. The disconnecting switch, circuit breaker and the insulator are arranged in a line. A vacuum switchgear comprises the above-mentioned vacuum switches of the number corresponding to three phases and necessary components, each being contained in a metal box.

Abstract: A third electrode (8A) is soldered, via a support fitting (9) onto the inner surface of a support part (1a) which projects into the intermediate part of the inner surface of an insulation tube (1A). An arc generated between the fixed-side contact (5A) and the movable-side contact (5B) when the switch is opened is led from the outer periphery of the fixed-side contact (5A) via the third electrode (8A) to the movable-side contact (5B), in a so-called two-point switch, and the dielectric breakdown probability is thus reduced, particularly at low voltages.

Abstract: The flux density Bct is applied at the center area of the electrode. The flux density Bct is adjusted within the range A of 0.75 to 0.9 times greater than the axial flux density Bcr which gives the lowest arc voltage between the electrodes against each breaking current.

Abstract: A breaking module for an electrical switchgear apparatus comprises a vacuum cartridge comprising a body and a support frame of the cartridge. The cartridge is provided with a metal rod movable in translation and driving a movable contact. A collar both performs radial positioning of the body of the cartridge with respect to the frame and constitutes a guide sheath of the rod. For fitting, the collar can be opened so as to insert the rod radially therein. Once the body of the cartridge has been encircled, the collar is inserted radially in guide grooves of the frame.

Abstract: A switchgear apparatus comprises a vacuum cartridge one contact of which is fixedly secured to a metal rod protruding out from the cartridge. A flexible metallic electrical connector designed to electrically connect the rod to a busbar is provided, at one of its ends, with a bored hole in which one end of the rod is inserted. The joint between the flexible electrical connector and the rod is achieved by means of a braze implementing a metallic filler compound having a low melting temperature, so as not to damage the cartridge when the brazing operation is performed.

Abstract: There is disclosed a vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same. Since the vacuum insulation, which is excellent in the insulation ability, is utilized, the switch is drastically miniaturized and the number of constituent parts are reduced, whereby the manufacturing cost of the switch and the switchgear can be decreased.

Abstract: A switching arrangement having a large burn-up reserve, contact fingers (2) are connected to a first electrical terminal via flexible bands (6) consisting of strips of, for example, copper which lie one above the other. The connecting portion (7) of the band (6), the said connecting portion adjoining the contact fingers (2) and being rigidly connected to them, is reinforced in each case by pressure welding of the strips. In the switch-off state, the bands (6) and, in part, the contact fingers (2) bear on an outwardly pointing supporting face (10), whilst, in the switch-on state, at least the contact fingers (2) and connecting portions (7) are lifted off from the supporting face (10), with the bands (6) being bent at the same time, as a result of contact with the outside of a switching pin (3) displaceable along a switching axis (1).

Abstract: Disclosed is a vacuum circuit breaker including a small-sized electrode structure capable of reducing deformation with age thereby enhancing the reliability and a vacuum bulb and a vacuum bulb electrode used for the breaker. In the vacuum circuit breaker, each of a fixed electrode and a movable side electrode includes an arc electrode made from particles of a refractory metal material, a high conductive metal material and a low melting point metal; an electrode supporting portion, made from the high conductive metal material, for supporting the arc electrode; a back conductor having a diameter smaller than the electrode supporting portion; and an external side connecting portion having a diameter larger than that of the back conductor. The arc electrode is integrated with the electrode supporting portion, back conductor, and external side connecting portion by the high conductive metal material, preferably, by melting of the highly conductive metal material.

Abstract: A load break interrupter includes a case, an arc-suppressing tube mounted on and projecting outwardly from the case, a shunt circuit rod slidably supported in the tube with the rod and tube having electrical contacts mounted thereto and convertible between make and break conditions upon sliding of the rod into and from the tube, and a shunt circuit break actuating mechanism disposed in the case and coupled with a leading end of the rod extending into the case such that upon tripping of the actuating mechanism from a shunt circuit-defining position to a shunt circuit-breaking position the rod is pulled partially into the case from the tube thereby breaking the shunt circuit through the rod and between the electrical contacts such that any arcing that occurs upon breaking of the shunt circuit is confined and suppressed inside the tube.

Abstract: A vacuum switch 1 includes a grounded vacuum vessel 2. The reliability of monitoring and measuring the vacuum pressure is improved by providing a vacuum pressure measuring terminal 30 at a side plane of the vacuum vessel 2 such that a main circuit 13 and the measuring terminal 30 are electrically separated from each other.

Abstract: An erosion gauge tool for measuring the erosion of a movable contact in a circuit breaker having a stationary contact and movable contact, both of which are sealed in a housing. The movable contact is coupled to a drive insulator. An erosion mark is etched on the housing adjacent to the drive insulator. The erosion gauge tool has a handle, a tab, and a pointer. The tab is adapted to rest on the drive insulator. The pointer is disposed adjacent to erosion mark when said tab is resting on said drive insulator. As the moveable contact erodes, the pointer moves closer to the erosion mark. The erosion gauge is sized to indicate when the moveable contact needs to be replaced, e.g. when the pointer is immediately adjacent to or above the erosion mark.

Abstract: A vacuum insulation switch provided with a movable electrode, a stationary electrode and an earthing electrode, which are insulated from each other, in a vacuum container made of a conductive material which is earthed, and a switchgear using the same.

Abstract: A bellows, of which one end portion is fixed to a movable lever passing through a vessel wall and the other end portion of which is fixed to the vessel wall, has a spring constant at a central portion in an expansion direction which is smaller than that at the end portions in the expansion direction. The bellows damps stress concentration at the end portions and improves the life thereof, without enlarging the size of the bellows. The bellows may be used in a vacuum switch.

Abstract: A vacuum switching apparatus for automatically performing a series of breaking and disconnecting operations includes a fixed electrode and a movable electrode mounted in a vacuum vessel. The movable electrode is sequentially movable between a closing position, an opening position and a disconnecting position. After the movable electrode passes through the opening position located between the closing position and the disconnecting position, the between-electrode opening speed of the movable electrode is reduced by a decelerating means. With this configuration, it is possible to move the movable electrode from the closing position to the disconnecting position without lowering the breaking performance, and hence to automatically perform a series of breaking and disconnecting operations.

Abstract: In an insulated type switching device, during rotation of a movable conductor 19 around a pivotal axis 35 between a stationary conductor 16 and a ground conductor 17 all of which are disposed in a vacuum vessel 12, the movable conductor 19 uninterruptedly takes four positions of closing position Y1, opening position Y2, disconnecting position Y3 and grounding position Y4, thereby a series of switching operations can be performed uninterruptedly, the operation and handling thereof are facilitated as well as the size of the insulated type switching device is reduced.