Composite (e.g., With Overlay) Patents (Class 337/296)
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Patent number: 6724292Abstract: An object is to provide a thermal fuse that is free of a trouble of welding contact between a movable electrode (4) and a lead (2) even when temperature of an equipment to which the thermal fuse is connected rises gradually and that has small electric resistance at the time of conduction.Type: GrantFiled: November 14, 2002Date of Patent: April 20, 2004Assignees: NEC Schott Components Corporation, Tokuriki Honten Co., Ltd.Inventors: Ikuhiro Miyashita, Tokihiro Yoshikawa, Michihiko Nishijima, Hideo Kumita
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Patent number: 6664886Abstract: A fuse that includes an arc energy reducing coating to reduce arc energy during a short-circuit and/or a full voltage overload current interrupt is described. The fuse includes end conductor elements, and at least one fuse element secured between and making electrical contact with the end conductor elements. An elongate fuse housing, having a passageway extending longitudinally through the housing, extends between the end conductor elements. The fuse element extends through the housing passageway. An arc energy reducing coating at least partially coats each end portion of the fuse element.Type: GrantFiled: November 21, 2002Date of Patent: December 16, 2003Assignee: Cooper Technologies CompanyInventor: John Marvin Ackermann
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Patent number: 6661330Abstract: The present invention relates to a fuse and a method for forming a fuse over a semiconductor substrate. The fuse comprises forming a first contact member and a second contact member over a respective first region and a second region of a patterned, electrically-conductive silicide layer, wherein the first contact member and the second contact member electrically contact the silicide layer, thereby defining a first interface and a second interface, respectively. A first contact area and a second contact area are associated with the respective first contact member and second contact member, wherein the first contact area is larger than the second contact area, thereby defining a fusible link at the second interface. According to one example, the silicide resides over a patterned polysilicon layer, wherein the patterned polysilicon layer generally tapered, and wherein the first region is wider than the second region.Type: GrantFiled: July 23, 2002Date of Patent: December 9, 2003Assignee: Texas Instruments IncorporatedInventor: Bradley Scott Young
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Publication number: 20030169144Abstract: The invention provides a thermal fuse and a fuse element of the low-melting fusible alloy type in which the fuse element has an alloy composition of 48 to 60% In, 10 to 25% Sn, and the balance Bi, and a total of 0.01 to 7 weight parts of at least one selected from the group consisting of Au, Ag, Cu, Ni, and Pd is added to 100 weight parts of the composition. As a result, the operating temperature is in the range of 57 to 67° C., requests for environment conservation can be satisfied, the diameter of the fuse element can be made very thin or reduced to about 300 &mgr;m&phgr;, self-heating can be suppressed, and the thermal stability can be satisfactorily guaranteed.Type: ApplicationFiled: March 4, 2003Publication date: September 11, 2003Applicant: Uchihashi Estec Co., Ltd.Inventor: Yoshiaki Tanaka
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Publication number: 20030156005Abstract: The invention is to offer a fuse and a fuse production method excellent in cost down. A fuse having an electrically conductive fuse element. The fuse element has a pair of terminal connection portions and a fusible member for electrically connecting the terminal connection portions each other and for being fused and broken when an over electric current flows. At least a part of the fusible portion is formed by spouting or dropping the melting metal drops.Type: ApplicationFiled: February 20, 2003Publication date: August 21, 2003Applicant: YAZAKI CORPORATIONInventors: Hitoshi Ohashi, Tatsuya Kato, Hitoshi Ushijima, Hiroyo Ayuzawa
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Patent number: 6570482Abstract: An electrical fuse includes a pair of terminal portions and a fusible link extending between the pair of terminal portions. The fusible link includes a fusing portion and a modifying portion in contact with the fusing portion. The modifying portion is formed of a material having a lower melting point than the fusing portion, and the fusible link includes a hole extending therethrough and defining an open-sided receptacle. A side of the open-sided receptacle forms one side of the fusing portion, and the modifying portion is disposed within the substantially open-sided receptacle.Type: GrantFiled: March 7, 2001Date of Patent: May 27, 2003Assignee: Cooper TechnologiesInventors: Russell Brown, Rognvald Ridley Peterson, Stuart Richard Roberts
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Publication number: 20030076214Abstract: A fuse that includes an arc energy reducing coating to reduce arc energy during a short-circuit and/or a full voltage overload current interrupt is described. The fuse includes end conductor elements, and at least one fuse element secured between and making electrical contact with the end conductor elements. An elongate fuse housing, having a passageway extending longitudinally through the housing, extends between the end conductor elements. The fuse element extends through the housing passageway. An arc energy reducing coating at least partially coats each end portion of the fuse element.Type: ApplicationFiled: November 21, 2002Publication date: April 24, 2003Inventor: John Marvin Ackermann
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Patent number: 6507265Abstract: A fuse that includes an arc energy reducing coating to reduce arc energy during a short-circuit and/or a full voltage overload current interrupt is described. The fuse includes end conductor elements, and at least one fuse element secured between and making electrical contact with the end conductor elements. An elongate fuse housing, having a passageway extending longitudinally through the housing, extends between the end conductor elements. The fuse element extends through the housing passageway. An arc energy reducing coating at least partially coats each end portion of the fuse element.Type: GrantFiled: April 13, 2000Date of Patent: January 14, 2003Assignee: Cooper Technologies CompanyInventor: John Marvin Ackermann
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Patent number: 6452475Abstract: A protective device comprises a fuse element provided to electrodes on a substrate. The fuse element has a liquidus point higher than the mounting temperature of the protective device, and has a solidus point lower than the mounting temperature of the protective device. The difference between the liquidus and solidus points is 5° C. or higher.Type: GrantFiled: April 4, 2000Date of Patent: September 17, 2002Assignee: Sony Chemicals Corp.Inventors: Masami Kawazu, Norikazu Iwasaki
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Patent number: 6222438Abstract: A temperature fuse which is melted with high operating temperature accuracy at a desired predetermined temperature in the range of 140° C. to 160° C. A fuse element is made of an alloy consisting essentially of 52-100 wt. % indium and the balance tin, and with this construction there can be achieved the temperature fuse which is melted with high operating temperature accuracy at a desired predetermined temperature in the range of 140° C. to 160° C.Type: GrantFiled: July 2, 1998Date of Patent: April 24, 2001Assignee: Yazaki CorporationInventors: Kinya Horibe, Takayoshi Endo, Takashi Ishii
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Patent number: 6163244Abstract: A method for producing a fuse element having a fusible portion and any other portion which are made of different kinds of metal. The method comprises the steps of boring through-hole in a substrate made of first metal, forming an element plate by fusion-bonding a second metal to the through-hole and integrally stamping a pair of substrate portion made of the first metal and a low-melting-point portion made of the second metal. The second metal is made of a metal whose melting point is lower than that of the first metal. Further, the pair of substrate portion is connected together by the low-melting-point portion so that the fuse element is formed.Type: GrantFiled: December 16, 1998Date of Patent: December 19, 2000Assignee: Yazaki CorporationInventors: Takayoshi Endo, Takashi Ishii
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Patent number: 6078245Abstract: A thin film surface-mountable fuse for protection against electrical overload. The fuse comprises a substrate, fusible link, a containment compound, and a pair of terminal pads. The fusible link is produced from a first conductive material and supported on the substrate. A diffusion bar of a second conductive material is deposited on a portion of the fusible link. The containment compound is also deposited over a portion of the fusible link. The containment compound inhibits migration of the diffusion bar along the fusible link during an electrical overload. The terminal pads are electrically connected to the fusible link and also supported by the substrate.Type: GrantFiled: December 17, 1998Date of Patent: June 20, 2000Assignee: Littelfuse, Inc.Inventors: Sandra E. Fritz, Anthony Minervini, Thomas Restis
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Patent number: 6075434Abstract: A fusible element for an electrical fuse comprising a generally flat, strip-shaped body having a generally uniform cross-section; a constricted area formed in the body has a cross-section less than the cross-section of the body; an indentation formed in the body at least bordering on the constricted area; a solder coating disposed within the indentation; and a first solder stop coating on a first surface of the body that is disposed adjacent the solder coating to prevent migration of the coating along the surface.Type: GrantFiled: January 19, 1999Date of Patent: June 13, 2000Assignee: Ferraz S.A.Inventor: Hans-Werner Rueckling
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Patent number: 6064293Abstract: A thermal fuse, preferably for a high-temperature battery, comprising leads and a body therebetween having a melting point between approximately 400.degree. C. and 500.degree. C. The body is preferably an alloy of Ag--Mg, Ag--Sb, Al--Ge, Au--In, Bi--Te, Cd--Sb, Cu--Mg, In--Sb, Mg--Pb, Pb--Pd, Sb--Zn, Sn--Te, or Mg--Al.Type: GrantFiled: October 14, 1997Date of Patent: May 16, 2000Assignee: Sandia CorporationInventors: Rudolph G. Jungst, James R. Armijo, Darrel R. Frear
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Patent number: 6040754Abstract: A thin type thermal fuse is structured by a resin base film, a pair of belt-shaped lead conductors, a low melting-point fusible alloy piece, flux and a resin cover film. Tip portions of the pair of belt-shaped lead conductors is fixed on the resin base film. The low melting-point fusible alloy piece is coupled between the tip end portions of the belt-shaped lead conductors. The flux applied on the low melting-point fusible alloy piece. The resin cover film which is disposed on a one surface of the resin base film so that a space between said films at peripheries of both the resin cover film and the resin base film is sealed and a space between the resin cover film and the belt-shaped lead conductors is sealed. In the thin type thermal fuse, a relation of (V/L).sup.1/2 /d.ltoreq.1.Type: GrantFiled: February 26, 1999Date of Patent: March 21, 2000Assignee: Uchihashi Estec Co., Ltd.Inventor: Toshiro Kawanishi
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Patent number: 6034589Abstract: A surface mount fuse includes a plurality of substrate/arc suppressive layers, a plurality of fusible elements positioned between the substrate/arc suppressive layers and terminations connected to the ends of the fusible elements, such that the fusible elements are electrically connected in parallel. The surface mount fuse has greater amperage and voltage ratings than similarly sized conventional surface mount fuses. Additionally, the surface mount fuse has increased interrupt breaking capacity and superior mechanical properties.Type: GrantFiled: December 17, 1998Date of Patent: March 7, 2000Assignee: AEM, Inc.Inventors: Jeffrey D. Montgomery, Xiangming Li, Daniel H. Chang, Kenneth M. Wallace, Kenneth X. Kuang
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Patent number: 6008716Abstract: The present invention provides a fuse structure formed in an inter-layer insulator having a first level interconnection and a second level interconnection isolated by the inter-layer insulator from the first level interconnection. The fuse structure comprises a conductive plug for providing an electrical connection between a first connecting part of the first level interconnection and a second connecting part of the second level interconnection, wherein the fuse structure further comprises at least a void which extends within the inter-layer insulator and also at least a part of the void extends adjacent to the second connecting part of the second level interconnection, so that when the second connecting part is rapidly evaporated by receiving a thermal energy, an evaporated material of the second connecting part is deposited on an inner wall of the void for causing an electrical disconnection between the first and second interconnections.Type: GrantFiled: September 21, 1998Date of Patent: December 28, 1999Assignee: NEC CorporationInventor: Tetsuya Kokubun
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Patent number: 6002322Abstract: A thin film, surface-mounted fuse which comprises two material subassemblies. The first subassembly comprises a fusible link, its supporting substrate and terminal pads. The second subassembly comprises a protective, photoimageable layer which overlies the fusible link so as to provide protection from impacts and oxidation. The photoimageable layer is a low profile coating.Type: GrantFiled: May 5, 1998Date of Patent: December 14, 1999Assignee: Littelfuse, Inc.Inventors: David J. Krueger, Brian J. Bullock, Honorio S. Luciano
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Patent number: 5936509Abstract: The fusible element of an electrical fuse is made from carbon glass. The carbon glass melts and pulls apart safely when the fuse blows, so the fusible element normally does not need an enclosure. The carbon glass glows and emits light when current flowing therethrough approaches the fuse's current-carrying capacity, thereby acting as a current sensor and a warning indicator that the fuse is about to blow.Type: GrantFiled: October 3, 1997Date of Patent: August 10, 1999Assignee: Lucent Technologies Inc.Inventors: David A. Norte, Woong K. Yoon
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Patent number: 5923239Abstract: A printed circuit board assembly comprising a printed circuit board having a plurality of conductive traces deposited on a surface thereof to define a plurality of electrical circuit geometries. A plurality of thin film fuses are deposited on the printed circuit board, each fuse providing circuit protection to one of the plurality of conductive traces.Type: GrantFiled: December 2, 1997Date of Patent: July 13, 1999Assignee: Littelfuse, Inc.Inventors: David J Krueger, Andrew J. Neuhalfen
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Patent number: 5914649Abstract: A chip fuse comprising an organic resin-made insulating substrate, a pair of electrodes formed at terminals of said organic resin-made insulating substrate, current protecting element wiring portions and a current protecting element positioned between said pair of electrodes and housed in said organic resin-made insulating substrate, said current protecting element having a thickness of 3-8 .mu.m and being supported on an organic resin layer having a high tracking resistance, and at least one space being formed at least on the current protecting element side, does not cause ignition nor smoking and is excellent in clearing characteristics.Type: GrantFiled: December 16, 1997Date of Patent: June 22, 1999Assignee: Hitachi Chemical Company, Ltd.Inventors: Tadashi Isono, Yoshiyuki Tsuru, Yutaka Taniguchi, Fumio Suzuki
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Patent number: 5793275Abstract: There is described a fuse comprising a housing and a current carrying strip of metal comprising a fuselink enclosed in the housing, each end of which electrically extends through the housing as an electrical connection. There being at least one first section of the metal strip for severing upon predetermined fault conditions, and at least one second section of the metal strip, distanced from the first section, having the properties of a hinge for pivoting. There further being at least one exothermic source in the proximity of the first section that substantially upon severance of the metal strip at the first section is ignited, and causes at least one segment of the severed metal strip to be propelled about the second section comprising the hinge. There further being an arc chute in proximity to the path of the moving severed edge of the first section such that fault current limiting is obtained.Type: GrantFiled: October 21, 1996Date of Patent: August 11, 1998Inventor: Arthur H. Iversen
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Patent number: 5661448Abstract: A chain of fuse-links is made from an electrically conductive metal plate. Each fuse-link P4. has an arc-shaped fusing portion 1 and a couple of terminal portions 4, 4 constituting a pair of wing-shaped members connected to each end of the arc-shaped fusing portion 1. A carrier strap 9 has a plurality of vertical connecting pieces 8 each positioned at fixed intervals for retaining the plurality of fuse-links P4. Each of a plurality of interconnection pieces 7 is connected to the vertical connecting piece 8 at one end and connected to a side edge of specific side one of the couple of terminal portions at the other end. The other end of the interconnection piece 7' is bent so that the end edges of the couple of terminal portions 4, 4 rise above the carrier strap 9.Type: GrantFiled: April 10, 1996Date of Patent: August 26, 1997Assignee: Yazaki CorporationInventors: Mitsuhiko Totsuka, Hisashi Hanazaki
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Patent number: 5262751Abstract: A fuse includes a meltable and conductive metal element mainly containing Cu and having a blowout portion, and a low-melting-point metal chip fixed at the blowout portion. The low-melting-point metal chip comprises a Sn-Cu alloy. Preferably, the low-melting-point metal chip comprises an alloy containing 0.5 to 3.5% by weight of Cu and all the residual content of Sn. Also preferably, the low-melting-point metal chip comprises an alloy containing 0.5 to 3.5% by weight of Cu, 1.0 to 6.0% by weight of Sb and all the residual content of Sn.Type: GrantFiled: December 8, 1992Date of Patent: November 16, 1993Assignee: Yazaki CorporationInventors: Toshiharu Kudo, Masahiro Kanda, Mitsuhiko Totsuka
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Patent number: 5130689Abstract: Gold, copper, silver, palladium or aluminum and their alloys, but preferably gold or gold alloy, which may be in the form a wire, has deposited thereon or contained within the wire, a material such as metals or metal alloys which diffuse into the gold or into the other listed metals. With the passage of time and exposure to temperature the deposited metal or metal alloy continues to diffuse into the gold forming intermetallics with the gold and thereby causing the resistivity of the gold to increase and causing the gold to become progressively more brittle until such time as the gold wire ruptures at a stress point. At a given temperature the elapsed time until rupture takes place depends upon the metal or metal alloys deposited on or contained within the gold. Lead, indium, gallium, tin, bismuth and aluminum and the alloys of these metals diffuse into and form intermetallics with the gold.Type: GrantFiled: January 16, 1991Date of Patent: July 14, 1992Assignee: Leach & Garner Co.Inventors: Grigory Raykhtsaum, Dwarika P. Agarwal
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Patent number: 5099218Abstract: A binary electrical fuse is comprised of a core wire which is preferably relatively rigid, has a high ohmic resistance, and a high melt temperature. The core wire is clad with a metal of substantially less rigidity having a low ohmic resistivity, and low melt temperature, i.e. in the range of from about 230 degrees C. to 700 degrees C. The resistance of the core wire is at least about ten times the resistance of the cladding and preferably twenty or more times the resistance of the cladding. In the course of a fusing cycle the cladding metal will melt and pool, leaving the core wire as the sole conductor resulting in a rapid blow of the fuse due to the sudden high resistance load presented by the core wire.Type: GrantFiled: December 7, 1990Date of Patent: March 24, 1992Assignee: AVX CorporationInventor: Ian Salisbury
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Patent number: 4944084Abstract: A fuse comprising a fuse element made by fixing a low-melting-point metal chip to a high-melting-point metal conductor, in which oxidatoin of the portions of the metal chip that are in contact with the metal conductor is prevented by [either partially fusing or soldered the metal chip to the metal conductor, or by] forming a layer of oxidation resistant material over the metal chip and then partially fusing the metal chip to the metal conductor.Type: GrantFiled: March 22, 1989Date of Patent: July 31, 1990Assignee: Yazaki CorporationInventors: Kinya Horibe, Hirohiko Fujimaki
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Patent number: 4869972Abstract: Disclosed is a fuse material consisting of aluminum or a rollable aluminum alloy having a copper plating deposited thereon and optionally being provided with a tin plating deposited on the copper plating. A fuse made of the fuse material shows a small temperature rise and has an extended useful service life as compared to conventional fuses.Type: GrantFiled: February 9, 1988Date of Patent: September 26, 1989Assignee: Yazaki CorporationInventor: Yuuji Hatagishi
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Patent number: 4654620Abstract: An asymmetrical fuse link employs a planar conductive member with the top and bottom surfaces manifested by having a series of alternating partial apertures with the alternating apertures in the top surface being of a first larger area followed by a second smaller area followed by a next larger area and so on. The bottom surface of the link also having a plurality of alternating partial apertures with the smaller diameter aperture of the bottom surface aligned with a larger diameter aperture in the top surface and so on. Thus the top and bottom surfaces each have partial apertures, with one of which is of a larger area and the next of a smaller area and arranged along a common axis and separated by a central aperture. Based on the above construction of the link, an arc generated during current interruption of the fuse is caused to zig zag along opposite edges of the planar member from a first to a second end.Type: GrantFiled: March 14, 1986Date of Patent: March 31, 1987Assignee: Commercial Enclosed Fuse Co. of New JerseyInventors: William J. Rooney, Francis J. Rooney
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Patent number: 4540970Abstract: A circuit breaking element comprising an electrically insulating base member, an organic insulation layer having a low melting point and formed over the surface of the base member, and a metal resistance coating layer formed over the surface of the insulation layer. When the metal resistance coating layer is thermally broken by excessive current passing therethrough, the coating layer completely separates into two portions at opposite sides of the break to completely break a circuit.Type: GrantFiled: February 29, 1984Date of Patent: September 10, 1985Inventor: Mikizo Kasamatsu
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Patent number: 4503415Abstract: There is disclosed an encapsulated fuse link whereby a lower melting point metal such as tin is deposited between two reduced cross sectional areas of a higher melting point base material such as copper or silver which forms the major surface area of the link. The area upon which the lower melting point metal is deposited is encapsulated by means of nonconductive material such as a high temperature plastic tube which is secured to the major surface of the link by some means such as staples at either end. The structure prevents the low melting point metal from migrating or traveling down the fuse link during operation which would undesirably tend to alter the characteristics of the fuse.Type: GrantFiled: June 6, 1983Date of Patent: March 5, 1985Assignee: Commercial Enclosed Fuse Co. of NJInventors: William J. Rooney, Francis J. Rooney
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Patent number: 4494104Abstract: A fuse for responding to external temperatures to interrupt an electrical circuit, for example for interrupting a telephone battery feed in response to the temperature of a battery feed resistor, comprises a substrate carrying a pair of electrodes defining a gap between them. A fuse link, for example a gold strip, extends across the gap to interconnect the electrodes electrically. A film of solder overlies the fuse link and overlaps at least partly at least one of the electrodes. The fuse link is soluble in the molten solder so when the temperature of the solder paste exceeds its melting point, it melts, dissolves the fuse link, and retreats from the gap to sever the electrical connection between the electrodes.The fuse and a resistor whose temperature is to be detected, may be provided on a single substrate.Type: GrantFiled: July 18, 1983Date of Patent: January 15, 1985Assignee: Northern Telecom LimitedInventor: Edward S. B. Holmes
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Patent number: 4459464Abstract: The present disclosure relates to an electric cigar lighter for use, for example in vehicles, having a circuit breaker. The circuit breaker includes an elongated fuse member having a fuse and a tube for covering the fuse. The tube has a melting point slightly lower than that of the fuse. Therefore, when the fuse melts and separates in two parts upon overheating of a heating element carried by an igniting of the lighter, the separated ends of the fuse are wrapped by the separated ends of the tube. Thus, even if the separated ends of the fuse member contact some portions of the lighter placed adjacent to the fuse member or other members, a short circuit can be prevented.Type: GrantFiled: September 28, 1982Date of Patent: July 10, 1984Assignee: Kabushiki Kaisha Tokai Rika Denki SeisakushoInventors: Akira Oda, Takashi Ozaki, Masahiko Kato, Kunio Kato, Teiji Kanamori
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Patent number: 4453662Abstract: Solder wire attached along its length to a base metal by a small quantity of solder melted at the solder-base metal juncture.Type: GrantFiled: February 10, 1982Date of Patent: June 12, 1984Assignee: Technical Materials, Inc.Inventor: Robert J. Russell, II
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Patent number: 4369421Abstract: A delayed safety device in which a meltable conductor engages two contacts. The meltable conductor is shielded by a non-conductive sleeve which serves also as touch protection. The meltable conductor is of a base metal having a coating of synthetic plastic which decomposes when heated and emits hydrochloric acid. The acid reacts with the conductor and reduces its cross-section. The coating protects the conductor against corrosion, and provides the conductor with switching-off characteristics present when the conductor is made of a noble metal.Type: GrantFiled: July 16, 1981Date of Patent: January 18, 1983Inventor: Christian Felsch
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Patent number: 4367451Abstract: A fusible element for electric fuses including a core or layer of copper, an outer layer of silver plating, and an M-effect overlay on the silver layer of a low fusing point metal, e.g. tin, capable of severing the current path through the plating of silver and the core of copper by a metal diffusion process.The M-effect overlay is arranged in spaced relation in regard to the point of the fusible element where the highest temperature prevails to maximize the temperature difference, or temperature gradient, between the M-effect overlay and the hottest point of the fusible element when the latter is carrying current.Type: GrantFiled: August 12, 1980Date of Patent: January 4, 1983Assignee: Gould Inc.Inventor: Robert J. Panaro
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Patent number: 4357588Abstract: A high voltage fuse for interrupting a wide range of currents and especially suited for low current interruption is disclosed. The fuse is comprised of a fuse element having a first and a second plurality of portions of reduced cross-sections. The second plurality of portions further comprise two or more parallel conducting paths some of which carry a portion of material which has a lower melting temperature than the melting temperature of the material of the fuse element. The parameters of the first and second plurality of reduced cross-section portions, the lower melting point material, and the fuse element itself are selected to adapt the fuse to provide proper protection for the various current conditions to which a high voltage transformer is subjected. The fuse element provides fast rupturing under short-circuit current conditions while also providing the characteristic of withstanding relatively high inrush current conditions.Type: GrantFiled: June 3, 1981Date of Patent: November 2, 1982Assignee: General Electric CompanyInventors: John G. Leach, James J. Carroll
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Patent number: 4339742Abstract: A high voltage fuse having mounted gas evolving members and method of forming such a fuse are disclosed. The high voltage fuse comprises, in part, a plurality of block shaped gas evolving members attached to a plurality of fuse elements, which, in turn, are wound about a supporting core. The high voltage fuse also has an electrically insulating casing in which is mounted the core having the wound fuse elements and the attached blocks of gas evolving members. The fuse casing is filled with a pulverulent arc quenching filler material. The block shaped gas evolving members have a narrow slit which allows the gas evolving members to be easily slipped over the fuse element so as to cover part or all of a transverse portion of the fuse. The gas evolving members are positioned over the fuse element at locations along the core so that the block type gas evolving members are arranged between adjacent portions of the ribs of the core.Type: GrantFiled: June 4, 1981Date of Patent: July 13, 1982Assignee: General Electric CompanyInventors: John G. Leach, Robert E. Koch
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Patent number: 4331947Abstract: A laminated electric safety fuse which is built up laminated design consisting of various conductive materials which are embedded on an electrically insulating supporting member. The supporting member comprises one or more layers of electrically insulating material, a predominant part of which is a material having good thermal conductivity.In this design a narrowing effect is obtained which is up to 10 times larger than in known fuses, without sacrificing the current-carrying capacity of the non-narrowed parts of the fuse element.The various layers from which the safety fuse is built up can consist of materials with different electric conductivity, providing a new variable for obtaining an increased narrowing effect. The individual layers can be built up as films, e.g. by evaporative deposition.Type: GrantFiled: April 15, 1980Date of Patent: May 25, 1982Assignee: Aktieselkabet Laur. Knudsen Nordisk ElectricitetsInventor: Olav Noerholm
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Patent number: 4320374Abstract: The invention involves new high voltage current limiting fuses employing composite metal fuse elements. One metal of the composite is aluminum which is of high conductivity and high melting point while the other is cadmium which is of low melting point, so that melting of the low melting point metal occurs at any and all locations along the element when its temperature reaches the said low melting point. The resulting composite exhibits properties that are not the mean of the metals employed and has a reversible resistance characteristic thus facilitating the design of the fuse for low current fault interruption.Type: GrantFiled: May 22, 1980Date of Patent: March 16, 1982Assignee: Kearney-National (Canada) LimitedInventors: Vojislav Narancic, Milenko Braunovic
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Patent number: 4315235Abstract: A composite fusible element of silver and copper includes an inlay of silver and a base formed by a thicker strip of copper than the inlay of silver. The strip of copper is severed by a pair of juxtaposed incisions, so that the entire current is carried at this particular point only by the strip of silver. Moreover, the incisions penetrate into the strip of silver, producing in it a point of reduced cross-section. The strip of copper is preferably provided with a concave groove. The strip of silver is preferably convex and fits into the concave groove of the strip of copper. The composite fusible element may include several parallel strips of silver in a joint base of copper.Type: GrantFiled: July 31, 1980Date of Patent: February 9, 1982Inventor: Philip C. Jacobs, Jr.
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Patent number: 4246563Abstract: A laminated electric safety fuse which is built up laminated design consisting of various conductive materials which are embedded on an electrically insulating supporting member. The supporting member comprises one or more layers of electrically insulating material, a predominant part of which is a material having good thermal conductivity.In this design a narrowing effect is obtained which is up to 10 times larger than in known fuses, without sacrificing the current-carrying capacity of the non-narrowed parts of the fuse element.The various layers from which the safety fuse is built up can consist of materials with different electric conductivity, providing a new variable for obtaining an increased narrowing effect. The individual layers can be built up as films, e.g. by evaporative deposition.Type: GrantFiled: May 18, 1978Date of Patent: January 20, 1981Assignee: Aktieselkabet Laur. Knudsen Nordisk ElectricitetsInventor: Olav Noerholm
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Patent number: 4227168Abstract: A fusible element for electric fuses based on M-effect, i.e. the severing of a high fusing point base metal by a low fusing point overlay metal by a process of metal interdiffusion. The M-effect, or Metcalf effect, as widely used in electric fuses, has a main limitation consisting in requiring too long periods of time for severing the base metal. The problem of severing the base metal by the overlay metal in shorter times is solved, according to this invention, by arranging the overlay metal on the front side and on the rear side of the base metal, in spaced relation to a point of reduced cross-section of the base metal.While the invention is applicable to all M-effect fuses, it is of particular importance in regard to Standard for Class L fuses of the Underwriters Laboratories Inc. which have fusible elements that are of copper, as distinguished from Class L fuses having fusible elements of silver, or Class L fuses having fusible elements in part of copper, and in part of silver.Type: GrantFiled: May 31, 1979Date of Patent: October 7, 1980Assignee: Gould Inc.Inventor: Edward J. Knapp, Jr.
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Patent number: 4227167Abstract: Fuses having different ratings, all of which comply with the Standard for Class L fuses of the Underwriters Laboratories Inc.The fusible elements of the fuses have identical points of reduced cross-section which fuse simultaneously on major fault currents, except one point of reduced cross-section which fuses ahead of the others.A relatively large temperature gradient prevails between the aforesaid points of reduced cross-section that fuse on short circuit current and the M-effect low fusing point overlay of the copper links that severs the current path through the latter by a diffusion process. The M-effect overlay metal may just reach its fusing point, while the immediately adjacent points of reduced cross-section may have a much higher temperature, e.g. 300.degree. to 400.degree. C. Thus the fusing M-effect metal will flow to the point of higher temperature and a rapid severing of the latter will take place.Type: GrantFiled: May 16, 1979Date of Patent: October 7, 1980Assignee: Gould Inc.Inventors: Frederick J. Kozacka, Howard G. Wilks
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Patent number: 4219795Abstract: A fusible element for electric fuses combining considerable time lag with current-limiting action. Time lag is achieved by providing the fuse with a combination of a plurality of means for achieving this end, such as folding the perforated center portion of the fusible element twice in a direction longitudinally thereof to achieve mutual heating of the folded portion, providing the center portion with end portions or heat dams of reduced cross-section which limit the flow of heat from the center portion to the terminals of the fuse, and are folded in transverse direction, and providing the fusible element with means capable of severing the fusible element by a metallurgical reaction, widely known as M-effect. The M-effect means increase time lag because of their mass and because they derate the fusible element. They cause severing of the center portion of the fusible element and are heated, in addition to i.sup.2 .multidot.Type: GrantFiled: October 18, 1978Date of Patent: August 26, 1980Assignee: Gould Inc.Inventors: Robert J. Panaro, Philip C. Jacobs, Jr.
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Patent number: 4216457Abstract: A fusible element for electric fuses capable of combining time-lag in the range of overload currents with current-limiting action for currents in the range of short-circuit currents. The fusible element comprises a relatively wide perforated center section and axially outer heat dam sections. The center section has points of reduced cross-section imparting to it a predetermined fusing i.sup.2 .multidot.t. The center section of the fusible element is folded in a direction longitudinally thereof to effect mutual heating of the portion, or portions, thereof to different sides of the fold, or folds. This allows to increase the mass of the center section and results in an increase of time-lag. Relatively narrow heat-dam-strip sections extend from the ends of said center section. The fusing i.sup.2 .multidot.Type: GrantFiled: August 8, 1978Date of Patent: August 5, 1980Assignee: Gould Inc.Inventor: Robert J. Panaro
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Patent number: 4146863Abstract: A one piece fusible conductor wherein a current carrying isthmus member in the form of a bridge connects first and second members. The first member has a hole in the vicinity of the isthmus and the hole is filled with a rivet shaped solder deposit and defines current carrying regions of the first member leading to the isthmus. In accordance with the invention, the horizontal profile E of the cross section of each of the latter regions is within a range of 0.7 to 1.00mm and the horizontal profile D of the cross section of the isthmus is within a range from 1.0 to 2.00mm. Furthermore, the profiles E and D satisfy approximately the following relationship: 0.75 .gtoreq. E/D .gtoreq. 0.5.Type: GrantFiled: March 1, 1977Date of Patent: March 27, 1979Assignee: Siemens AktiengesellschaftInventor: Klaus Mollenhoff
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Patent number: 4118684Abstract: In a one piece fusible conductor of the type having cutouts for narrowing the path of current so as to form current carrying isthmuses with a hole filled with a solder deposit adjacent each isthmus, the cross section at each isthmus has a definite relation to the cross section of the material between the hole containing the solder deposit and the diamond shaped cutouts.Type: GrantFiled: March 8, 1977Date of Patent: October 3, 1978Assignee: Siemens AktiengesellschaftInventor: Klaus Mollenhoff
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Patent number: 4055827Abstract: The electric time-lag fuse involves a substantially T-shaped shorting strip shorting the insulating gap formed between a pair of metal overlays on an insulating strip, and a helical tension spring having a variable diameter affixed with one of the ends thereof to said T-shaped shorting strip, and resting with the other end thereof against the annular surface of a tubular member.Type: GrantFiled: November 10, 1976Date of Patent: October 25, 1977Assignee: Gould, Inc.Inventor: Edward J. Knapp, Jr.
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Patent number: RE30158Abstract: A layer of material is disposed over at least a portion of a resistive film of a resistor. The material having a melting point lower than the melting point of the resistive film and when melted, chemically reacts with the resistive film to render at least a portion of the film non-conductive.Type: GrantFiled: October 9, 1974Date of Patent: November 20, 1979Assignee: P. R. Mallory & Co. Inc.Inventors: James B. Bucklin, Jay Utken