With Nozzle Patents (Class 218/53)
  • Patent number: 11322322
    Abstract: An insulating molded body to be used for an arc extinguishing device of a gas circuit breaker is provided. The insulating molded body includes a fluororesin mixture which contains a fluororesin and an oxygen generator configured to generate oxygen through thermal decomposition at 450° C. or more and 1,150° C. or less with an arc generated when a conduction current is interrupted. The oxygen generator is dispersed in the fluororesin. Also provided is a gas circuit breaker including an insulating nozzle formed of the insulating molded body.
    Type: Grant
    Filed: October 30, 2018
    Date of Patent: May 3, 2022
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shuichi Hiza, Takashi Kawana, Fumihiko Hosokoshi, Motohiro Sato, Kenji Mimura
  • Patent number: 10991527
    Abstract: A contact piece for a high-voltage circuit breaker includes at least a contact pin and a contact carrier. The contact carrier is configured to mechanically fasten the contact pin in the high-voltage circuit breaker. The contact pin includes a contact shaft. The contact carrier and the contact shaft are formed as a monolithic contact element. A method for producing a contact piece is also provided.
    Type: Grant
    Filed: September 5, 2017
    Date of Patent: April 27, 2021
    Assignee: Siemens Aktiengesellschaft
    Inventors: Sebastian Huebner, Martin Krehnke, Volker Lehmann
  • Patent number: 10347446
    Abstract: To improve cooling performances of quenching gas in a gas blast switch comprising a gas channel connecting an arcing region to a gas storage chamber delimited by radially opposite inner and outer walls and axially opposite first and second end walls, a flow guiding radial wall extends in the gas storage chamber spaced from each wall delimiting the chamber, an opening of the gas channel into the gas storage chamber through the first end wall faces a space between the flow guiding radial wall and the inner wall, the outer wall includes a deflecting portion protruding in the gas storage chamber and facing the second end wall, and at least part of the deflecting portion is offset from the flow guiding radial wall in an axial direction oriented from the gas channel towards the gas storage chamber.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: July 9, 2019
    Assignee: General Electric Technology GmbH
    Inventors: Joel Ozil, Quentin Rognard, Othman Zakaria, Damien Vancell
  • Patent number: 9029726
    Abstract: A circuit breaker includes a first contact and a second contact. An electric arc zone is disposed between the contacts. A feed channel opens into the electric arc zone, connecting the electric arc zone to a hot gas reservoir volume. The hot gas reservoir volume, in turn, is connected to a compression volume. An outflow opening is disposed in a wall of the compression volume. The outflow opening is permanently open, at least in a contacting state of the contacts.
    Type: Grant
    Filed: May 3, 2011
    Date of Patent: May 12, 2015
    Assignee: Siemens Aktiengesellschaft
    Inventor: Radu-Marian Cernat
  • Publication number: 20150069018
    Abstract: The present disclosure relates to a circuit breaker having a compact contact assembly structure, including a stationary portion; and a movable portion to be contact with or to be separated from the stationary portion, wherein the movable portion includes a puffer cylinder configured to temporarily store a compressible fluid; a moving main contact assembled to an end of the puffer cylinder; and a moving nozzle inserted into the moving main contact, and the moving main contact includes an internal protrusion protruded in a radial direction and separated in a circumferential direction from an inner surface thereof, and the moving nozzle includes an external protrusion protruded in a radial direction and separated in a circumferential direction on an external surface thereof, and the internal and external protrusions are alternately coupled to the puffer cylinder, respectively, by a fastening member along the circumferential direction.
    Type: Application
    Filed: May 30, 2014
    Publication date: March 12, 2015
    Applicant: LSIS CO., LTD.
    Inventor: Chenxin LIU
  • Patent number: 8859926
    Abstract: In one configuration of the present invention, a hair extension device for providing a user with the appearance of having longer, fuller hair is disclosed. The device may have a hair cluster having a hair flap which in turn comprises one or more hair wefts. The hair wefts may contain a number of hair strands connected together by seams which composes the band. The device may contain a filament which may be sandwiched between one or more flaps. The hair wefts may be sewn together with thread using a zig-zag stitch for example. The hair extension device may be reversible and the wefts may be attached to a length of lace.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: October 14, 2014
    Inventor: Michelle Elizabeth Freelove
  • Patent number: 8859925
    Abstract: An electric switchgear includes an interrupter unit having a first connecting line and a second connecting line. The interrupter unit is disposed inside a fluid-tight encapsulating housing that is filled with an electrically insulating fluid. The interrupter unit is further surrounded by a shielding housing in at least some sections. The first connecting line has a flow channel for the fluid. A first outlet opening of the flow channel leads to the shielding housing and a second outlet opening leads to the exterior of the shielding housing.
    Type: Grant
    Filed: February 7, 2011
    Date of Patent: October 14, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventors: Norbert Lüthy, Tomasz Magier, Manfred Meinherz, Clemens Rüthnick
  • Patent number: 8698033
    Abstract: An insulating tube (18) located between the main contacts (12b, 14b) and the arcing contacts (12a, 14a) of an interrupting chamber (10) of a high-voltage or medium-voltage circuit-breaker makes it possible to modify the distribution of the equipotential lines (V) during breaking. Thus, it is possible to reduce the electric field on the contacts, and thus to improve the breaking and the dielectric strength in the open position. The insulating tube (18) can also serve for transmitting movement between the contacts (12, 14) for triggering the circuit-breaker.
    Type: Grant
    Filed: October 8, 2007
    Date of Patent: April 15, 2014
    Assignee: Alstom Technology Ltd
    Inventors: Joël Ozil, Christophe Creusot, Jean-Luc Bourgeois, Yannick Kieffel
  • Patent number: 8664558
    Abstract: A high-voltage power switch has a switch gap surrounded by a nozzle made of insulating material. The nozzle of insulating material is formed with a switching gas channel. The switching gas channel opens up into a storage volume. A flow steering apparatus is disposed within the storage volume. The flow steering apparatus has a switching gas entrance channel. An annular gap is formed between the wall in which the switching gas channel opens up and a switching gas entrance channel wall that borders the switching gas channel.
    Type: Grant
    Filed: August 11, 2009
    Date of Patent: March 4, 2014
    Assignee: Siemens Aktiengesellschaft
    Inventor: Shibani Bose
  • Patent number: 8598483
    Abstract: A switching device assembly with a contact gap has a nozzle made of insulating material. The nozzle made of insulating material is formed with a nozzle channel that ends in a hot gas space. A deflector element is arranged within the hot gas space. The deflector element is supported inside the deflector channel.
    Type: Grant
    Filed: January 22, 2010
    Date of Patent: December 3, 2013
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hold Dienemann, Volker Lehmann, Manfred Meinherz
  • Patent number: 8304676
    Abstract: Disclosed is a gas insulated switchgear constituted such that electrical contacts are placed inside a sealed vessel filled with an arc extinguishing gas, and when electrical current passes, the electrical contacts are held in contact and pass electricity, and when the current is interrupted, the electrical contacts are separated and an arc discharge is produced in the arc extinguishing gas, and the current is interrupted by extinguishing this arc. The arc extinguishing gas is a mixed gas, the main constituents of which are N2 gas and CH4 gas, and the CH4 content is at least 30%. Alternatively, the arc extinguishing gas is a mixed gas, the main constituents of which are CO2 gas and CH4 gas, and the CH4 content is at least 5%.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: November 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiyuki Uchii, Yoshihiko Hirano, Yoshikazu Hoshina
  • Patent number: 8269126
    Abstract: The invention provides a gas insulated switchgear, and a method for detecting arc damage in a part used in a gas insulated switchgear, which detect directly when an electric contact or a peripheral part reaches an initially set wear limit. An insulating nozzle of a circuit breaker contains a marking substance that releases a gaseous substance inside a circuit breaker gas container as a result of wear by an arc. For ensuring heat resistance and insulation properties, the insulating nozzle is ordinarily formed of a fluororesin, but in the present invention, it is formed of the ordinarily used fluororesin having uniformly mixed therein, as the marking substance, a chlorine-containing resin which has excellent heat resistance and insulation properties such as polyvinylidene chloride.
    Type: Grant
    Filed: September 13, 2010
    Date of Patent: September 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yukio Kanazawa, Masahiro Hanai, Hiroshi Furuta
  • Patent number: 8129647
    Abstract: An insulating nozzle is formed with a first and a second material. The first material has a lower erosion resistance than the second material. The insulating nozzle has an insulating nozzle duct. The surfaces defining the insulating nozzle duct are at least partially made out of the second material. The insulating nozzle duct is formed with a hollow cylindrical section. An inner casing surface and an outer casing surface of the hollow cylindrical section is made out of the second material at least partially.
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: March 6, 2012
    Assignee: Siemens Aktiengesellschaft
    Inventor: Tommy Haberer
  • Publication number: 20110297647
    Abstract: A switchgear assembly has a contact gap and an insulating material nozzle. The insulating material nozzle at least partly encloses the contact gap. A nozzle channel for the insulating material nozzle opens with a outlet opening in a hot gas space. A deflector element is disposed within the hot gas space which defines a deflector channel. The deflector channel has a segment which has an expanding cross-section in the stream direction of a switching gas in the hot gas space.
    Type: Application
    Filed: January 26, 2010
    Publication date: December 8, 2011
    Applicant: SIEMENS AKTIENGESELLSCHAFT
    Inventors: Radu-Marian Cernat, Hold Dienemann, Stefan Giere, Volker Lehmann, Manfred Meinherz
  • Publication number: 20100224594
    Abstract: A gas-insulated circuit breaker has a sealed container filled with gas; a pair of contacts so constructed as to be connected and separated each other in the sealed container; gas flow generation means for blasting the gas on an arc generated when the contacts are separated, the gas flow generation means including: an accumulation space, pressure increasing means for increasing the pressure of the pressure accumulation space, a gas passage connecting the pressure accumulation space to the arc, and an insulating nozzle that controls the flow of the gas from the pressure accumulation space to the arc; an inside-nozzle insulating member disposed co-axially with the insulating nozzle. The arc is generated in a space between an inner wall section of the insulating nozzle and an outer wall section of the inside-nozzle insulating member, and the gas flows in the space.
    Type: Application
    Filed: March 4, 2010
    Publication date: September 9, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Toshiyuki UCHII, Tadashi Mori, Takeshi Shinkai
  • Patent number: 7645957
    Abstract: A nozzle for a medium or high voltage gas switching device of the type having at least a couple of separable arc contacts (1, 2), comprising a hollow shaped body (100) suitable to be positioned inside the device around the zone (20) where electric arcs form between said arc contacts (1, 2) during switching operations, characterized in that said hollow shaped body (100) has a first portion (101) electrically conductive and a second portion (102) made of electrically insulating material which surrounds at least partially said first portion (101).
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: January 12, 2010
    Assignee: ABB Technology AG
    Inventors: Roberto Capitanio, Carlo Cereda
  • Patent number: 7642480
    Abstract: In order to reduce the breaking energy of a high-voltage or medium-voltage circuit-breaker, the interrupting chamber (10) contains two contacts (12, 14) mounted to move in opposite directions, and actuated via a single device (20). The two contacts (12, 14) are surrounded by an insulating casing (18) of tubular shape, coupled in fixed manner to the main contact (12). The contacts (12, 14) are actuated by a device having a lever (24) in which each lever arm is coupled to a link, one of the links (32) being secured to the insulating casing (18) and the other link (34) being secured to the second contact (14). The guiding of the drive tube (18) on the main contacts (12b, 14b) makes it possible to improve breaking by keeping clean gas between said main contacts.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: January 5, 2010
    Assignee: Areva T&D SA
    Inventors: Joel Ozil, Christophe Creusot, Jean-Luc Bourgeois, Yannick Kieffel
  • Publication number: 20090134123
    Abstract: A method of evacuating hot gases produced in a current breaking operation by a high voltage circuit breaker (1) which comprises a metal outer tank (2) filled with insulating gas, a casing (3) having gas outlet ports (30) and arranged inside the metal outer tank (2), with which it is in communication via the said ports, characterized in that insulating gas (GI) is aspirated from inside the casing (3) in a direction parallel to the flow of the hot gases (GC) produced by the current breaking operation, so as to mix the gases inside the casing (3) before they are evacuated, through the said gas outlet ports (30) of the casing, into the interior of the metal outer tank (2). The invention also relates to an associated high voltage circuit breaker, which includes means (5) for aspirating insulating gas from the interior of the casing (3), in a direction parallel to the hot gas stream.
    Type: Application
    Filed: November 13, 2008
    Publication date: May 28, 2009
    Applicant: AREVA T&D SA
    Inventors: Wolfgang GRIESHABER, Roger LEDRU, Steven GROSICK, Nicklas DAVISON
  • Publication number: 20090107957
    Abstract: Described is a high-voltage circuit breaker provided with two opposite-arranged arcing contacts, which are surrounded by an insulating nozzle. Furthermore provided are two main contacts, arranged opposite each other outside of the insulating nozzle, with respectively one of these contacts being assigned to one of the two arcing contacts. The high-voltage circuit breaker is provided, in at least one embodiment, with at least one device for diverting an insulating gas flow from the region between the two arcing contacts, wherein a respective insulating gas flow is conducted outside of the insulating nozzle and in the direction toward the main contacts.
    Type: Application
    Filed: August 15, 2008
    Publication date: April 30, 2009
    Inventors: Ing Lutz Drews, Gregoire Cyril
  • Patent number: 7507931
    Abstract: The switching chamber is intended for a gas-insulated high-voltage circuit breaker. It contains an axially symmetrical housing and a contact arrangement held in the housing with two switching pieces, of which at least one is arranged such that it can move along the housing axis. The switching chamber housing has two hollow bodies consisting of electrically conductive material which can be connected to a high voltage and an insulating tube holding the hollow bodies axially at a distance. A separation zone, which is electrically shielded during operation of the circuit breaker, is formed in the surface of at least one of the two hollow bodies and separates two surface zones having different degrees of roughness from one another in the hollow body. In homogeneities in the surface of the switching chamber housing which may reduce the dielectric strength of the circuit breaker equipped with the switching chamber therefore do not have any effect.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: March 24, 2009
    Assignee: ABB Technology AG
    Inventors: David Saxl, Markus Vestner
  • Publication number: 20080314873
    Abstract: A switching chamber is intended for a gas-insulated high-voltage switch and contains a contact arrangement with two arcing contacts, which move relative to one another along an axis, with an insulating nozzle, an insulating auxiliary nozzle, a heating volume and a heating channel. The heating channel is routed partially axially between the insulating nozzle and the insulating auxiliary nozzle and connects an arcing zone to the heating volume. A section of the heating channel which opens into the heating volume is inclined inward with respect to the axis. Hot gas which is formed when a short-circuit current is disconnected in the arcing zone therefore flows with a velocity component directed inward into the heating volume, and can penetrate deeply into the heating volume in areas close to the axis.
    Type: Application
    Filed: August 28, 2008
    Publication date: December 25, 2008
    Applicant: ABB Research Ltd
    Inventors: Andreas DAHLQUIST, Christian Franck, Martin Seeger
  • Patent number: 6744001
    Abstract: A high-voltage circuit-breaker including a valve for decompressing a thermal blast chamber includes two contacts disposed in a breaking space which is delimited by a blast nozzle and contains a dielectric gas. It further includes a thermal blast chamber which communicates with the breaking space via a throat of the nozzle and with an expansion space via an evacuation passage which can be shut off by a valve. The valve opens when the pressure in the thermal blast chamber is greater than a particular threshold to evacuate the pressurized gas from the chamber. The evacuation passage is formed in the nozzle and defines a circular volume within the thickness of the nozzle, following its general shape, and opening into the expansion space downstream of the breaking space relative to the throat.
    Type: Grant
    Filed: March 12, 2003
    Date of Patent: June 1, 2004
    Assignee: Alstom
    Inventors: Denis Dufournet, Michel Perret
  • Patent number: 6740837
    Abstract: A contact zone (1) of a quenching chamber which is arranged rotationally symmetrical about a central axis (2) and is filled with an insulating medium, having at least two stationary consumable contacts which are in the form of contact rings (4, 15) and which, when the quenching chamber is closed, are electrically conductively connected by means of a bridging contact which is arranged centrally and can move axially. The mutually facing end surfaces of the consumable contacts are partially covered by electrically insulating covers (11, 22). The aim is to provide insulating covers which are designed to have good dielectric characteristics and are easy to install.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: May 25, 2004
    Assignee: ABB Schweiz AG
    Inventors: Lukas Zehnder, Michael Mendik
  • Patent number: 6646850
    Abstract: A high-voltage power breaker includes two arcing contact pieces which are separated from one another when disconnected and between which an arc is struck in an arcing area. The arcing area is filled with a quenching gas, where the quenching gas has been heated by the arc flowing out from a constriction point of an insulating nozzle. The insulating nozzle surrounds the arcing area, through at least one outlet flow channel which has a number of areas which the quenching gas passes through successively. The first area which faces the constriction point of the nozzle has a specific flow resistance which is less than that of the constriction point. The first area in the outlet flow direction of the quenching gas is followed by at least one second area, one third area and one fourth area. The specific flow resistance of the second and fourth areas are each greater than the specific flow resistance of the immediately preceding area in the outlet flow direction.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: November 11, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventors: Ralf Bergmann, Hold Dienemann, Joerg Hagen, Hartmut Knobloch, Volker Lehmann, Friedrich Loebner, Michael Punger, Claudia Wiesinger
  • Patent number: 6483064
    Abstract: An insulating blast nozzle for a circuit breaker, the circuit breaker having a first arcing contact and a second arcing contact that separate from each other when the circuit breaker is opened subsequent to prior separation of permanent contacts, said insulating blast nozzle being secured to one of the permanent contacts and being generally horn-shaped, having a throat and defining a volume of revolution having an upstream portion and a downstream portion joined by the throat, in which the inside volume is cylindrical and closed by the second arcing contact when the circuit breaker is closed and for a few milliseconds after the arcing contacts have separated, the wall of the nozzle in its portion defining the upstream portion of said volume of revolution surrounding said first arcing contact, the downstream portion of said volume comprising a first conical portion, wherein said first conical portion is followed by a second conical portion having a flare angle that is more open than that of said first conical
    Type: Grant
    Filed: April 25, 2001
    Date of Patent: November 19, 2002
    Assignee: Alstom
    Inventors: Denis Dufournet, Wolfgang Grieshaber, Michel Perret
  • Patent number: 6472629
    Abstract: An electric switch includes a first arcing contact surrounded by a puffer break chamber in which the gas is pressurized by the thermal effect, and a second arcing contact movable along an axial direction relative to the first arcing contact. The break chamber includes an inner partition separating a first compartment of fixed volume from a second compartment of smaller volume, both compartments being filled with the gas under pressure and each possessing an orifice to blast the arc, the orifices being separate and placed in series along the axial direction. Each compartment is connected to its own orifice via a respective blast channel. The compartments communicate with each other via a channel that is closed by an excess pressure vent device allowing gas at excess pressure to pass in one direction only from the smaller volume compartment to the larger volume compartment.
    Type: Grant
    Filed: April 17, 2001
    Date of Patent: October 29, 2002
    Assignee: Alstom
    Inventor: Denis Dufournet
  • Patent number: 6462295
    Abstract: In a high-voltage power breaker having two rated current contact pieces and two arc contact pieces as well as an insulating nozzle, a filling body is provided, which is mounted on this insulating nozzle, surrounds the insulating nozzle in an annular shape and is composed of an electrically insulating material having a high dielectric constant, in order to influence the electric field in the isolating gap.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: October 8, 2002
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hartmut Knobloch, Heinz-Helmut Schramm
  • Publication number: 20010045410
    Abstract: An insulating blast nozzle for a circuit breaker, the circuit breaker having a first arcing contact and a second arcing contact that separate from each other when the circuit breaker is opened subsequent to prior separation of permanent contacts, said insulating blast nozzle being secured to one of the permanent contacts and being generally horn-shaped, having a throat and defining a volume of revolution having an upstream portion and a downstream portion joined by the throat, in which the inside volume is cylindrical and closed by the second arcing contact when the circuit breaker is closed and for a few milliseconds after the arcing contacts have separated, the wall of the nozzle in its portion defining the upstream portion of said volume of revolution surrounding said first arcing contact, the downstream portion of said volume comprising a first conical portion, wherein said first conical portion is followed by a second conical portion having a flare angle that is more open than that of said first conical
    Type: Application
    Filed: April 25, 2001
    Publication date: November 29, 2001
    Inventors: Denis Dufournet, Wolfgang Grieshaber, Michel Perret
  • Patent number: 6040970
    Abstract: An interrupter unit of a high-voltage circuit breaker has two arcing contacts, between which an arc is formed in the event of switch-off. A nozzle made of insulating material is provided for blowing out the arc. The nozzle made of insulating material is screwed together with a cylindrical component of the interrupter unit using a thread. In order to secure the thread, a connection piece is provided, which can be inserted in or set on the nozzle made of insulating material, and has a knurling, which can be pressed into the nozzle made of insulating material.
    Type: Grant
    Filed: February 16, 1999
    Date of Patent: March 21, 2000
    Assignee: Siemens AG
    Inventors: Volker Lehmann, Joachim Gericke
  • Patent number: 5925863
    Abstract: The power breaker is provided with a contact arrangement which is equipped with erosion-resistant contact members and has a stationary contact member (4), a contact member (4) which can move along a central axis (6) and an insulating nozzle (6) which concentrically surrounds the contact members (3, 4) and has a constriction (6). The insulating nozzle (6) is manufactured from an erosion-resistant plastic and is structured such that erosion channels which are formed run at right angles to the direction of the electrical field load. This insulating nozzle emits gases during disconnection, which particularly effectively support the production of blowing pressure in the arc zone.
    Type: Grant
    Filed: August 29, 1997
    Date of Patent: July 20, 1999
    Assignee: ABB Research Ltd.
    Inventors: Lukas Zehnder, Kurt Kaltenegger, Lorenz Muller, Lutz Niemeyer
  • Patent number: 5902980
    Abstract: An insulating component for use in high-voltage switching equipment, especially gas-insulated switching gear. A nozzle made of an insulating material is used in a power switch. Portions of the surface of the nozzle subject to high dielectric stresses in use are provided with increased surface roughness in the form of grooves. These grooves may be cut by a lathe.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: May 11, 1999
    Assignee: Siemens Aktiengesellschaft
    Inventors: Frank Reincke, Norbert Trapp
  • Patent number: 5654532
    Abstract: The movable nozzle of a puffer circuit interrupter has a coaxial cylindrical shield connected to its downstream end and the main movable contacts connected to its upstream end. The shield is electrically connected to the stationary contact terminal. The movable contact ring and coaxial shield at the upstream end of the nozzle define a well shielded open gap when the interrupter gap opens.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: August 5, 1997
    Assignee: ABB Power T&D Company Inc.
    Inventors: Jeffry R. Meyer, Joachim Stechbarth, Kurt Kaltenegger
  • Patent number: 5453591
    Abstract: A vaporizable material, for example, a silicone, that is buried beneath the surface of a Teflon nozzle for a sulfur hexafluoride power circuit breaker in an area of the nozzle which is exposed to abrasion and wear due to arc products. In a similar manner, aluminum or titanium or some other vaporizable material is buried beneath the surface of the contact of the circuit interrupter which is exposed to abrasion and wear. When the buried layers are exposed due to abrasion of their covering surfaces, these materials will be vaporized and their presence will be sensed by sensors within the circuit interrupter, thus revealing some predetermined degree of wear of the surfaces of the nozzle and contact and other surfaces within the circuit interrupter which may also be subject to abrasion by arcing or arc products. When aluminum is used as the vaporizable material for the contact, it also senses the presence of flashover to aluminum exterior housings.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: September 26, 1995
    Assignee: ABB Power T&D Company Inc.
    Inventor: Nicholas J. Stroud