US3818409A - Electric circuit breaking fuse - Google Patents

Electric circuit breaking fuse Download PDF

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Publication number
US3818409A
US3818409A US00357709A US35770973A US3818409A US 3818409 A US3818409 A US 3818409A US 00357709 A US00357709 A US 00357709A US 35770973 A US35770973 A US 35770973A US 3818409 A US3818409 A US 3818409A
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US
United States
Prior art keywords
fuse
fusible element
filler
liquid
capillary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00357709A
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English (en)
Inventor
V Grislis
J Pastors
A Litsitis
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Individual
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Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from SU1784353A external-priority patent/SU430760A1/ru
Application filed by Individual filed Critical Individual
Priority to US00357709A priority Critical patent/US3818409A/en
Priority to GB2228673A priority patent/GB1410443A/en
Priority to DE2323512A priority patent/DE2323512C3/de
Priority to FR7317758A priority patent/FR2184936B1/fr
Application granted granted Critical
Publication of US3818409A publication Critical patent/US3818409A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
    • H01H85/02—Details
    • H01H85/38—Means for extinguishing or suppressing arc
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
    • H01H85/02—Details
    • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
    • H01H85/041—Fuses, i.e. expendable parts of the protective device, e.g. cartridges characterised by the type
    • H01H85/044—General constructions or structure of low voltage fuses, i.e. below 1000 V, or of fuses where the applicable voltage is not specified
    • H01H85/0445—General constructions or structure of low voltage fuses, i.e. below 1000 V, or of fuses where the applicable voltage is not specified fast or slow type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H85/00—Protective devices in which the current flows through a part of fusible material and this current is interrupted by displacement of the fusible material when this current becomes excessive
    • H01H85/0039—Means for influencing the rupture process of the fusible element
    • H01H85/0043—Boiling of a material associated with the fusible element, e.g. surrounding fluid

Definitions

  • the present invention relates to electrical circuit breaking fuses, and more particularly to quick-acting fuses used for protecting the electric circuits of, for example, semiconductor rectifiers.
  • Fuses of this kind offer an essential advantage of providing a relatively high mean arc voltage gradient when cutting out over-currents, resulting in an efficient current-limiting feature. Furthermore, extinguishing of the arc in a fine-grained filler is accompanied by rather small over-voltage peaks.
  • the condensation area is too limited (the liquid usually occupied from two-thirds to three-quarters of the casing volume) and, consequently, when the fuse operates, the pressure is relatively low.
  • Another serious disadvantage of this kind of design consists in that, at large current values the hydrodynamic shock resulting from the explosion of the fuse propagates through the liquid as far as the walls of the fuse casing and is liable to cause its destruction.
  • fuses comprising an auxiliary electrode which is used to control the fusion conditions by producing an additional arc melting off the fusible element.
  • auxiliary electrode is used to shunt the circuit of the element being protected at the instant the arc is extinguished.
  • An object of the present invention is to provide a fuse having improved arc extinguishing characteristics and a higher rated current density in the fusible element.
  • Another object of the invention is to provide a fuse combining the advantages of fuses with powdered and liquid fillers.
  • a further object of the invention is to make use of an auxiliary electrode with a view to further raising the rated current density in the fusible element through a more efficient cooling thereof.
  • a fuse comprising a sealed casing partially filled with a liquid filler and having current leads, wherebetween a fusible element is included within the casing, in which, in accordance with the invention, the fusible element is embedded in a body of a capillary-porous material with communicating pores, which body is immersed in the liquid filler,
  • the body of a capillary-porous material, wherein the fusible element is embedded may be immersed in the liquid filler to the extent of only part of its volume, with the quantity of the liquid filler employed being minimum but sufficient to fill the pores throughout the entire volume of the body and to wet the inner surface of the fuse casing, thereby ensuring a continuous evaporation-condensation cycle of the tiller under nominal conditions of operation of the fuse.
  • the buffer volume formed within the fuse casing as it is filled with the liquid filler contain primarily the vapours of the liquid filler, with the foreign gases which fail to condense at the rated temperature of the fuse being kept practically at zero level.
  • a liquid-free gap be provided in the space between the body of a capillary-porous material and the side walls of the fuse casing as a means for checking the propagation of hydrodynamic shock as far as the walls of the casing.
  • the capillary-porous body may be formed as a briquet of quartz sand.
  • the fuse should be preferably provided with at least one auxiliary electrode electrically connected to a source of voltage, which electrode should set up, immediately adjacent the fusible element, an additional electric field which acts upon the boiling liquid in the pores of said body of a capillary-porous material adjoining the fusible element, thereby intensively cooling the latter.
  • the auxiliary electrode my be insulated from the tiller, or else it may be adapted to be conductively coupled to the fusible element through the tiller.
  • the fuse of the present invention functions as a liquid-filler fuse under rated current, and as a powdered fine-grained filler fuse under overcurrents.
  • dielectric liquids such as ditolylmethane
  • the presence of certain dielectric liquids, such as ditolylmethane, in the pores of the capillary-porous body having the fusible element embedded therein is liable to cause some deterioration of the arc extinguishing characteristic (in some caeses the arc voltage gradient drops by 20 percent), but raises the rated current density almost twofold as compared with a fusible element embedded in a dry fine-grained filler.
  • the quqntity of the liquid filler is preferably kept at a minimum, as has been noted hereinabove.
  • the quantity of the liquid filler can be minimized owing to the fact that the capillaryporous body serves as a wick raising the liquid to the fusible element, with the general level of the liquid filler remaining very low.
  • FIG. 1 shows a fuse in accordance with the invention, wherein the capillary-porous body is partially immersed in the liquid filler;
  • FIG. 2 shows a fuse in accordance with the invention, wherein the capillary-porous body is completely immersed in the liquid filler;
  • FIG. 3 shows a fuse in accordance with the invention, wherein the capillary-porous body is housed in the fuse casing with a gap in relation to the side walls of the cas-
  • FIG. 4 is a cathode oscillogram of the arc voltage in quartz sand with an addition of a dielectric liquid compared with an arc voltage oscillogram for pure quartz sand under the same conditions;
  • FIG. 5 is a curve of voltage losses as a function of current intensity for a fuse filled with a mixture of quartz sand and ethylene glycol, compared with a similar curve for pure quartz sand;
  • FIG. 6 shows a fuse in accordance with the invention, wherein the auxiliary electrode is conductively coupled to the fusible element through the filler;
  • FIG. 7 shows a fuse in accordance with the invention, wherein the auxiliary electrode is insulated from the filler
  • FIG. 8 is a graph showing the relationship between the voltage losses in the fusible element and the current intensity in the fuse which, in accordance with the invention, is provided with an auxiliary electrode.
  • the fuse comprises a sealed casing 1, containing leads 2 and 3 passed therethrough, and fusible elements 4 included intermediate of said leads 2 and 3, the fusible elements 4 being embedded in a body 5 of a capillary-porous material partially immersed in a liquid filler 6.
  • the liquid filler 6 fills the fuse only partially, thereby providing a buffer space 7 therein.
  • the quantity of the liquid filler is chosen to be minimum but sufficient to fill the pores of the entire body 5 and wet the inner surface of the casing 1 and the hollow leads 2 and 3. It is desirable that prior to being filled with the liquid filler 6 the fuse should be throughly outgassed, for example, by vacuum annealing, to prevent the formation of a vapour lock obstructing condensation.
  • the fusible element 4 gets heated, causing the liquid filler in the pores of the layer of the body 5 adjoining the fusible element 4 to boil, the vapour bubbles penetrate through the pores of the body 5 and condense on the inner walls of the casing l and the buffer space 7, giving off their heat to the upper lead 2.
  • the condensate flow down the walls of the casing 1 into its lower portion, wherefrom, under the effect of capillary forces, it again rises and gets into the area of the fusible element 4.
  • a body 8 of a capillary-porous material, having a fusible element 9 embedded therein is completely immersed in a liquid filler 10.
  • the fuse casing 11 is made from an impact-resistant material, such as metal, for the design of this fuse does not rule out the possibility of hydrodynamic shock.
  • the casing 11 is provided with ribs 12.
  • the fusible element 9 is coupled to leads 13 fixed in an insulator 14.
  • the body 8 is made of quartz sand tamped and fixed by a grid 15.
  • the fuse of this kind operates in a manner similar to that of the above-described one, except that capillary imbibition is facilitated by the complete immersion of the body 8 in the liquid filler 10, thereby preventing premature drying of the pores of the body 8 adjoining the fusible element 9.
  • FIG. 3 also comprises a sealed casing 16 and leads 17 including therebetween a fusible element 18 which is embedded in a body 19 of a capillary-porous material partially immersed in a liquid filler 20.
  • the body 19 is likewise made of quartz sand and is maintained at a gap a from the walls of the casing 16 by a cylindrical grid 21, which prevents the shock wave from reaching the walls of the casing. Therefore, the casing may be made from a material which need not be impact-resistant.
  • the liquid filler 20 penetrates through the grid 21 and makes it way into the body 19, wherefrom it is raised by capillary forces to the fusible element 18 and evaporates in the latters area.
  • the liquid vapours thus produced penetrate through the quartz sand and the grid 21 and condense on the inner wall of the casing 16, giving off their heat to the ribs of the casing 16.
  • FIG. 4 is a typical cathode oscillogram of arc voltage V (curve A) versus time for fuses employing fixed quartz sand as the body of a capillary-porous material and ethylene glycol as the liquid filler. It will be seen that the overvoltage peaks are quite low.
  • FIG. 4 gives an arc voltage oscillogram for the case of pure quartz sand (curve B).
  • curve A and B are similar which goes to prove that the mixture of quartz sand and ethylene glycol is practically equivalent by its arc-extinguishing properties to quartz sand free from any admixtures, and the latter is known as an excellent arc-extinguishing medium.
  • FIG. 5 illustrates voltage losses A V as a function of current intensity I for the same type of fuse.
  • the curve C represents the case of the filler being a mixture of quartz sand with ethylene glycol, while the curve D corresponds to the case of a pure quartz filler.
  • the straight line E represents the dependence of A V on I at a constant mean temperature of the fusible element 1 +1 C.
  • the thickness of the fusible element is 0.028 mm, and the minimum width of the intermediate portion of the fusible element is 0.54 mm.
  • the density of the rated current through the minimum cross-section of the fusible element is equal to 1,500 A/mm that is to say far higher than that of the quick-acting fuses of the other known types, whose current density if of the order of 400 to 600 A/mm
  • FIG. 6 and 7 represent alternative embodiments of the proposed fuse incorporating an auxiliary electrode.
  • the fuse of FIG. 6 comprises a sealed metal casing 22, an upper lead 23 being an extension thereof.
  • a lower lead 24 is hermetically secured in an insulator 25.
  • a fusible element 26 is included intermediate of the leads 23 and 24.
  • an auxiliary electrode 27 made as a thin metal spiral, said auxiliary electrode being conductively coupled to the fusible element 26 through a low-conducting filler.
  • the inner space 28 of the casing 22 is filled with a filler composed of a capillary-porous medium such as quartz sand and a dielectric liquid.
  • a strong grid 30 serving to fix the capillary-porous material.
  • the voltage V impressed between the lower lead 24 and the auxiliary electrode 27 sets up an electric field in the layer of the porous filler adjoining the fusible element 26. If the field intensity is high enough, the field will affect the boiling of the liquid phase of the filler, with the result that the rated current density in the fusible element may be chosen to be higher than in similar fuses containing no auxiliary electrode.
  • the fuse of FIG. 7 comprses leads 31 having disposed therebetween a capillary 32 made of heat-resistant (300 400 C.) insulating material, such as quartz glass or Teflon.
  • the capillary 32 is enveloped by fusible elements 33 bent as half-cylinders and welded to the leads 31.
  • the capillary 32 houses an auxiliary metal electrode34.
  • the casing 35 of the fuse is made ofa strong insulating material.
  • the main inner space 36 of the fuse is filled with the aforementioned filler (quartz sand plus dielectric. liquid). In thermal expansion, part of the liquid from the space 36 penetrates into the buffer space 38, through a narrow slit 37.
  • the effect of the electrode field results in a substantial intensification of the rate of evaporative cooling of the fusible element.
  • a voltage is applied to the auxiliary electrode at all times, both under nominal conditions and under overload accompanied by the melting of the fusible element and extinguishing of the arc, but it is of practical significance only at the rated current intensity, for the voltage is supplied through a high-resistance resistor or a lowcapacitance capacitor (not shown in FIG. 7) limiting the current through the high-voltage circuit to a value of the order of 1 mA too low to cause an arc discharge.
  • the present invention may be used to minimize the Joule effect, for the electric field acts to reduce the temperature of the fusible element, consequently reducing its resistance.
  • FIG. 8 illustrates the results of testing of one branch of the fusible element of a fuse, shown as the dependence of the drop of voltage A V in the fusible element on the current intensity I.
  • the fuse tested was a mockup with an auxiliary insulated electrode (FIG. 7).
  • the curve F represents the result for a filler composed of quartz sand and carbon tetrachloride, the voltage of the auxiliary electrode being equal to zero, that is to say in the absence of an electric field.
  • the curve G represents the results of experiments with the same filler and a SO-Hz 10 kV voltage across the auxiliry electrode. For comparison, a case is given with dry quartz sand used instead of said filler and the voltage V being equal to zero (curve H).
  • the fuse incorporating an auxiliary electrode is of the controlled operation type, since its melting characteristics are detennined by the voltage V on the auxiliary electrode. Thus, for instance, if the rated current value is close to the critical one, then cutting off the control voltage will cause the fusible element to melt off and the fuse to break the circuit.
  • An electrical circuit breaking fuse comprising a casing; leads passed through said sealed casing; a fusible element disposed intermediate of said leads; a liquid filler partly filling said casing; said liquid filler having a boiling point below that of said fusible element; a body of a capillary-porous material with communicating pores immersed in said liquid filler and having said fusible element embedded therein, part of the communicating pores of said body which are in direct contact with the fusible element serve to supply said liquid filler to the area of said fusible element under nominal operating conditions of the fuse, while, under overcurrent said body helps extinguish the arc producd in the fuse.
  • An electrical circuit breaking fuse as of claim 2, wherein said body of a capillary-porous material is only partially immersed in said liquid fill, the quantity of said liquid filler being minimum but sufficient to fill the pores of the entire said capillary-porous material and to wet the inner surface of said casing, thereby ensuring a continuous evaporation-condensation cycle of the filler under rated functioning conditions of the fuse.
  • An electrical circuit breaking fuse as of claim 3, wherein between said body of a capillary-porous material and the side walls of said casing of the fuse there is formed a liquid-free gap which prevents hydraulic shock from propagating as far as the side walls of the casing.
  • auxiliary electrode electrically connected to a source of voltage and setting up an additional electric field in the immediate vicinity of said fusible element, said additional electric field affecting the boiling of the liquid in the pores of said body of a capillary-porous material, thereby causing an intensive cooling of said fusible element.

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  • Fuses (AREA)
US00357709A 1972-05-17 1973-05-07 Electric circuit breaking fuse Expired - Lifetime US3818409A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US00357709A US3818409A (en) 1972-05-17 1973-05-07 Electric circuit breaking fuse
GB2228673A GB1410443A (en) 1972-05-17 1973-05-10 Electrical fuses
DE2323512A DE2323512C3 (de) 1972-05-17 1973-05-10 Schmelzsicherung
FR7317758A FR2184936B1 (OSRAM) 1972-05-17 1973-05-16

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SU1784353A SU430760A1 (ru) 1972-05-17 1972-05-17 Плавкий предохранитель
US00357709A US3818409A (en) 1972-05-17 1973-05-07 Electric circuit breaking fuse
GB2228673A GB1410443A (en) 1972-05-17 1973-05-10 Electrical fuses

Publications (1)

Publication Number Publication Date
US3818409A true US3818409A (en) 1974-06-18

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Application Number Title Priority Date Filing Date
US00357709A Expired - Lifetime US3818409A (en) 1972-05-17 1973-05-07 Electric circuit breaking fuse

Country Status (4)

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US (1) US3818409A (OSRAM)
DE (1) DE2323512C3 (OSRAM)
FR (1) FR2184936B1 (OSRAM)
GB (1) GB1410443A (OSRAM)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4058785A (en) * 1976-09-22 1977-11-15 General Electric Company Current limiting fuse
US4272752A (en) * 1979-07-30 1981-06-09 Gould Inc. Electric fuse including two different fillers
US5736919A (en) * 1996-02-13 1998-04-07 Cooper Industries, Inc. Spiral wound fuse having resiliently deformable silicone core
US6275135B1 (en) * 1998-10-01 2001-08-14 Yazaki Corporation Large current fuse for automobiles
US6710696B2 (en) * 2002-04-08 2004-03-23 Eaton Corporation Fuse housing for network protector
US20080204184A1 (en) * 2005-04-08 2008-08-28 Auto Kabel Managementgesellschaft Mbh Passive Triggering of a Circuit Breaker for Electrical Supply Lines of Motor Vehicles
US20100201475A1 (en) * 2007-10-26 2010-08-12 Kowalik Daniel P Micro-Fluidic Bubble Fuse
US20110237102A1 (en) * 2008-11-05 2011-09-29 Auto Kabel Managementgesellschaft Mbh Plug-In Connection for an Occupant Protection Means
CN102280326A (zh) * 2010-06-10 2011-12-14 揖斐电株式会社 印刷电路板、电子器件以及印刷电路板的制造方法
US20150340188A1 (en) * 2014-05-22 2015-11-26 Littelfuse, Inc. Porous inlay for fuse housing
US9892880B2 (en) 2014-05-22 2018-02-13 Littelfuse, Inc. Insert for fuse housing

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0305314A1 (en) * 1987-08-18 1989-03-01 A.B. Chance Company Pultruded or filament wound synthetic resin fuse tube
CN108007278B (zh) * 2017-12-17 2020-05-01 上栗县东森阳光烟花制造有限公司 一种防止错误燃放烟花的装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3194925A (en) * 1960-05-31 1965-07-13 Cole E K Ltd Electrical fuses immersed in a dielectric fluid
US3291942A (en) * 1966-12-13 Electric fuse with separate quartz fillers having different grain sizes
US3699491A (en) * 1971-10-07 1972-10-17 Gen Electric Fuse having vibration damping means for protecting the fuse link thereof
US3710295A (en) * 1971-06-01 1973-01-09 Gen Electric Current limiting fuse

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2223726A (en) * 1937-10-02 1940-12-03 Westinghouse Electric & Mfg Co Protective device for electrical apparatus and systems
GB1288222A (OSRAM) * 1969-06-25 1972-09-06
CH528816A (de) * 1971-03-15 1972-09-30 Bbc Brown Boveri & Cie Schmelzsicherung

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3291942A (en) * 1966-12-13 Electric fuse with separate quartz fillers having different grain sizes
US3194925A (en) * 1960-05-31 1965-07-13 Cole E K Ltd Electrical fuses immersed in a dielectric fluid
US3710295A (en) * 1971-06-01 1973-01-09 Gen Electric Current limiting fuse
US3699491A (en) * 1971-10-07 1972-10-17 Gen Electric Fuse having vibration damping means for protecting the fuse link thereof

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4058785A (en) * 1976-09-22 1977-11-15 General Electric Company Current limiting fuse
US4272752A (en) * 1979-07-30 1981-06-09 Gould Inc. Electric fuse including two different fillers
US5736919A (en) * 1996-02-13 1998-04-07 Cooper Industries, Inc. Spiral wound fuse having resiliently deformable silicone core
US6275135B1 (en) * 1998-10-01 2001-08-14 Yazaki Corporation Large current fuse for automobiles
US6710696B2 (en) * 2002-04-08 2004-03-23 Eaton Corporation Fuse housing for network protector
US8154377B2 (en) * 2005-04-08 2012-04-10 Auto Kabel Managementgesellschaft Mbh Passive triggering of a circuit breaker for electrical supply lines of motor vehicles
US20080204184A1 (en) * 2005-04-08 2008-08-28 Auto Kabel Managementgesellschaft Mbh Passive Triggering of a Circuit Breaker for Electrical Supply Lines of Motor Vehicles
US20100201475A1 (en) * 2007-10-26 2010-08-12 Kowalik Daniel P Micro-Fluidic Bubble Fuse
US8143990B2 (en) * 2007-10-26 2012-03-27 Daniel Kowalik Micro-fluidic bubble fuse
US20110237102A1 (en) * 2008-11-05 2011-09-29 Auto Kabel Managementgesellschaft Mbh Plug-In Connection for an Occupant Protection Means
CN102280326A (zh) * 2010-06-10 2011-12-14 揖斐电株式会社 印刷电路板、电子器件以及印刷电路板的制造方法
US8614898B2 (en) 2010-06-10 2013-12-24 Ibiden Co., Ltd. Printed wiring board, electronic device, and printed wiring board manufacturing method
CN102280326B (zh) * 2010-06-10 2015-02-18 揖斐电株式会社 印刷电路板、电子器件以及印刷电路板的制造方法
US20150340188A1 (en) * 2014-05-22 2015-11-26 Littelfuse, Inc. Porous inlay for fuse housing
US9607799B2 (en) * 2014-05-22 2017-03-28 Littelfuse, Inc. Porous inlay for fuse housing
US9892880B2 (en) 2014-05-22 2018-02-13 Littelfuse, Inc. Insert for fuse housing

Also Published As

Publication number Publication date
DE2323512C3 (de) 1980-07-31
FR2184936A1 (OSRAM) 1973-12-28
DE2323512B2 (de) 1979-11-15
GB1410443A (en) 1975-10-15
FR2184936B1 (OSRAM) 1977-07-29
DE2323512A1 (de) 1973-11-29

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