US3845439A - Method of manufacturing fuses - Google Patents

Method of manufacturing fuses Download PDF

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Publication number
US3845439A
US3845439A US00180786A US18078671A US3845439A US 3845439 A US3845439 A US 3845439A US 00180786 A US00180786 A US 00180786A US 18078671 A US18078671 A US 18078671A US 3845439 A US3845439 A US 3845439A
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US
United States
Prior art keywords
wire
fuse
core
fuse according
fibres
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
US00180786A
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English (en)
Inventor
G Deelman
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Littelfuse Tracor BV
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Littelfuse Tracor BV
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
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Application granted granted Critical
Publication of US3845439A publication Critical patent/US3845439A/en
Assigned to BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION, reassignment BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION, SECURITY INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TRACOR HOLDINGS, INC., TRACOR, INC., AND OTHERS INDICATED ON SCHEDULE SA
Anticipated expiration legal-status Critical
Assigned to TRACOR, INC. reassignment TRACOR, INC. RELEASED BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION
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
    • H01H85/04—Fuses, i.e. expendable parts of the protective device, e.g. cartridges
    • H01H85/05—Component parts thereof
    • H01H85/055—Fusible members
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H69/00—Apparatus or processes for the manufacture of emergency protective devices
    • H01H69/02—Manufacture of fuses
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49002—Electrical device making
    • Y10T29/49107—Fuse making
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49789—Obtaining plural product pieces from unitary workpiece
    • Y10T29/49798—Dividing sequentially from leading end, e.g., by cutting or breaking
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/49826—Assembling or joining
    • Y10T29/49885—Assembling or joining with coating before or during assembling
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T29/00—Metal working
    • Y10T29/49—Method of mechanical manufacture
    • Y10T29/4998—Combined manufacture including applying or shaping of fluent material
    • Y10T29/49982—Coating

Definitions

  • the length of the fusible wire is substantially fixed.
  • the current protection range of a conductive wire is known to be determined by parameters, such as the dimater, resistivity, length and melting point of the wire. In the case of a specific choice of material the current protection range is determined only by the diameter of the wire, since its length is substantially fixed. As only wires with a limited number of different diameters are commercially available, it is hardly possible to manufacture fuses for arbitrary current protection ranges.
  • a wire of a metal having a well defined melting point which metal at elevated temperature is substatially inert to environmental affects.
  • a material is e.g. silver.
  • silver is less suitable for low current values, since these low current values require such a small diameter that the wire is substantially unmanageable.
  • the relation between diameter and length of the wire should be such that the wire becomes too slack and tends to sag, which renders the fuse unreliable to a large extent,
  • the manufacture of fuses with very thin silver wires is practically impossible, since in mounting the silver wire in the container tube the wire tends to dissolve in the tin of the mounting places. Therefore, up to now fuses with silver wire have not been used in the case of current values less than 1A.
  • a possible solution for the above difficulties would be to replace the stretched wire by a winding disposed around an insulating core. [n this manner the core can serve as a support so as to prevent sagging, which makes it possible to use the so desired silver wire even when very small diameters are required.
  • the heat dissipating properties of such a core affect during use the heat properties of the winding. ln order to meet this objection the core should be a good heat insulator and should be so thin that its heat dissipation can substantially be neglected. Suitable core materials are, for instance, extremely thin wire of glass or quartz fibres or a similar material.
  • these wires should have a very small diameter in the order of 5-l0 microns, they are highly pliable and flexible, which makes it hardly possible to wind such wires with extremely fine metal wire, as during the winding process the lateral forces on the fibre material due to the winding operation may easily cause wire rupture.
  • the method according to the invention is characterized in that a very thin wire of electrically non-conductive, heat-insulating and heatresistive fibre material, which is provided with a thin layer of thermosetting material, is set or rigidified by heating, the set wire is wound with extremely thin metal wire, the wound wire is cut in defined segments and the segments are mounted in suitable containers.
  • the invention makes it possible to wind extremely thin cores, the heat dissipating properties of which are negligible, with micro-wire for obtaining a well defined fuse for low current values.
  • the fuse manfrfactured by this method is characterized in that the current conductor consists of extremely fine wire having a well defined melting point and the core consists of set fibre material of such a thickness that its heat dissipating property is negligible.
  • the core material is preferably composed of glass fibre wire or quartz fibre wire, the thickness of the composing fibres being in the order of 5-10 microns. It is also possible to use fibres of synthetic material capable of standing high temperatures.
  • the fibres or fibre bundles may include in longitudinal direction metal wires or straps, which form an integral part with the core owing to the winding.
  • the conductive function takes place owing to the winding material either or not in co-operation with the metal wires present possibly in longitudinal direction of the fibres.
  • the conductor material to be wound preferably consists of silver wire having a diameter in the order of 20-30 microns. If desired, a plurality of parallel metal wires can be used as a conductive winding.
  • the above construction furthermore reduces the socalled critical length of the fuse element considerably.
  • fuses with a very compact construction.
  • Such a compactness is particularly important for panels having a printed circuitry.
  • a fuse was constructed for 80 mA having a length of 3 mm by means of the method according to the invention.
  • FIG. 1 is a schematic side elevational view of a device suitable for winding :1 fibrous core yarn with metal wire.
  • FIG. 2 is a schematic representation in side elevational view of a device suitable for using the method according to the invention.
  • FIGS. 35 are representations in cross-section of fuses manufactured by means of the method according to the invention.
  • FIG. 1 shows a device which can be applied for the process of winding a conductive wire around a core formed by a glass fibre yarn.
  • a spool l with mounting 2 having a brake device contains a supply of glass fibre yarn 4. The yarn is wound under tensile stress on spool 6.
  • the spool 6 is driven by a motor 7 in such a way that the yarn passes through the winding device 8 at constant speed.
  • the winding head 8 contains a supply bobbin ll with the conductive metal wire 12.
  • the hollow shaft 9 is rotated by a motor (not shown) coupled through a V-belt with wheel 10 in such a manner that the wheel 10 rotates at constant speed.
  • the metal wire 12 is passed to the front side of the shaft 9 via a small guiding wheel 14, which is mounted on an arm located on the front side 13 of the bobbin 11.
  • the metal wire is thus progressively wound around the glass fibre yarn.
  • the glass fibre yarn is thus provided with a winding of metal wire with a constant pitch.
  • FIG. 1 The device described in the light of FIG. 1 can be applied conveniently for carrying out the method according to the invention.
  • FIG. 2 in which drawing the same reference numerals show the same parts as in FIG. 1.
  • the spool l the glass fibre yarn is unwound under tensile stress and is passed between the rubber rolls l5 and 16, which are driven by a motor not shown.
  • the rolls l5 and 16 contact each other and are urged against each other under such a pressure that the fibre yarn is unwound from the spool 1 without slippage owingto the effect of the roller.
  • the glass fibre yarn 4 coming from the spool l is provided with a thermosetting material layer.
  • the yarn 4 is passed through a heating device, which heating device comprises a bored material block 17.
  • a heating wire 18 is wound around the block 17.
  • the heating wire 18 is connected to the terminals 19 and 20 of a suitable power supply not shown. If the fibre yarn 4 passes through the bore in the heated block 17, the thermosetting layer on the fibre yarn is set, so that a rigidified fibre core leaves the heating device. Subsequently the core is passed through the winding device 8 and is wound with a metal wire in the manner described above.
  • the wound core is afterwards passed through a cutting device and is cut into segments by means of the blade 22 of the cutting device on the die 21. By effecting the cutting operation with certain intervals, segments of predetermined length are cut. The segments can subsequently be mounted in suitable containers to provide the fuses according to the invention.
  • FIG. 3 An example of fuses constructed in accordance with the invention is given in FIG. 3, in which 31 is a ferrule cemented to a cylindrical tube made of glass or any other suitable material and in whose axis the fuse ele' ment made of set or rigidified quartz fibres 34 with its conductive winding 33 is positioned by means of the eyelets 35.
  • a solder alloy forms the conductive connection between the winding 34 of said fuse element and the ferrules 31.
  • H6 Another suitable form that may be chosen in accordance with the invention is indicated in H6. 4, in which a cylindrical tube 42 made from percelain or any other suitable material is provided with end caps 41 made from copper or brass.
  • end caps 41 made from copper or brass.
  • the ends of the fuse elements with the conductive winding 44 around a set quartz fibre core 43 are bent around theedges of tube 42 in such a manner that the fuse element is in a diagonal position.
  • FIG. 5 Another advantageous construction is given by way of example in FIG. 5.
  • the fuse element is made of winding 54 with a concentration of its windings 56 in the middle of the element around a glass fibre core 53.
  • the concentration of the windings in the centre reduces the heat dissipation in the fuse in a favourable way.
  • the construction of the cylindrical tube 52 and end caps 51 is analogous to that of FIG. 4.
  • a fuse for use at current values of one ampere and less comprising a tubular insulating casing, conductive terminal means mounted on each end of said casing and a fuse element mounted in said casing between said conductive terminal means, said fuse element including an electrically non-conductive, heat-insulating and heat-resistive wire core of fibres rigidified with set thermosetting material, wherein at least one current conductor of extremely fine wire is wound around said core.
  • a fuse according to claim 1 wherein said fine wire is silver having a diameter less than 30 microns.
  • a fuse according to claim I wherein said fine wire is tin having a diameter less than 0.4 millimeters.
  • a fuse according to claim 1 wherein said fine wire is silver having a diameter in the order of -30 microns.
  • a low-current value fuse comprising a casing; spaced-apart conductive terminal means mounted on the casing; and a fuse element mounted in the casing between the conductive terminal means, said fuse element including an elongated rigid core which is electrically nonconductive, heat-insulating and heatresistive, said core being an extremely thin wire made of fibres having diameters of the order of 5--l 0 microns, said wire being rendered rigid by the presence of heatset thermosetting material in contact with said fibres, said fuse element further including at least one current conductor of extremely fine metal wire wound around said core.
  • a fuse according to claim 6 wherein said fine wire is silver having a diameter less than 30 microns.
  • a fuse according to claim 6 wherein said fine wire is tin having a diameter less than 0.4 millimeters.
  • a fuse according to claim 6 wherein said fine wire is silver having a diameter in the order of 20-30 microns.
  • a fuse according to claim 6 wherein said fine wire is tin having a diameter in the order of 0.2-0.4 millimeters.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Fuses (AREA)
US00180786A 1970-09-15 1971-09-15 Method of manufacturing fuses Expired - Lifetime US3845439A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL707013620A NL142815B (nl) 1970-09-15 1970-09-15 Werkwijze voor het vervaardigen van een smeltveiligheid, in het bijzonder voor geringe stroomsterkte, alsmede aldus vervaardigde smeltveiligheid.
US508714A US3885303A (en) 1970-09-15 1974-09-23 Method of manufacturing fuses

Publications (1)

Publication Number Publication Date
US3845439A true US3845439A (en) 1974-10-29

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ID=26644579

Family Applications (2)

Application Number Title Priority Date Filing Date
US00180786A Expired - Lifetime US3845439A (en) 1970-09-15 1971-09-15 Method of manufacturing fuses
US508714A Expired - Lifetime US3885303A (en) 1970-09-15 1974-09-23 Method of manufacturing fuses

Family Applications After (1)

Application Number Title Priority Date Filing Date
US508714A Expired - Lifetime US3885303A (en) 1970-09-15 1974-09-23 Method of manufacturing fuses

Country Status (7)

Country Link
US (2) US3845439A (xx)
BE (1) BE772443A (xx)
CH (1) CH536025A (xx)
FR (1) FR2106538B1 (xx)
GB (1) GB1304629A (xx)
NL (1) NL142815B (xx)
SE (1) SE383802B (xx)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2308190A1 (fr) * 1975-04-16 1976-11-12 San O Ind Co Fusible miniature a retard
FR2309969A1 (fr) * 1975-05-02 1976-11-26 San O Ind Co Composant electrique et son application a un fusible a retard miniaturise
US4122426A (en) * 1976-02-03 1978-10-24 San-O Industrial Corp. Time-lag fuse
DE2901423A1 (de) * 1978-02-03 1979-08-09 Wickmann Werke Ag Schmelzsicherung
US4189696A (en) * 1975-05-22 1980-02-19 Kenneth E. Beswick Limited Electric fuse-links and method of making them
US4293836A (en) * 1979-07-11 1981-10-06 San-O Industrial Co., Ltd. Electrical fuse with an improved fusible element
EP0046392A2 (en) * 1980-08-18 1982-02-24 Rte Corporation Full range current limiting fuse
US4369421A (en) * 1980-07-18 1983-01-18 Christian Felsch Safety device with delay
US4445106A (en) * 1980-10-07 1984-04-24 Littelfuse, Inc. Spiral wound fuse bodies
EP0116723A1 (en) * 1983-02-11 1984-08-29 Littelfuse-Olvis A.G. Electrical cartridge fuselinks and a method of manufacturing same
US4517544A (en) * 1983-10-24 1985-05-14 Mcgraw-Edison Company Time delay electric fuse
US5130688A (en) * 1988-11-21 1992-07-14 Littlefuse Tracor B.V. Fuse
US5736919A (en) * 1996-02-13 1998-04-07 Cooper Industries, Inc. Spiral wound fuse having resiliently deformable silicone core

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL151209B (nl) * 1972-06-22 1976-10-15 Olvis Nv Smeltveiligheid en werkwijze voor het vervaardigen van een dergelijke smeltveiligheid.
US4041525A (en) * 1976-04-05 1977-08-09 The Chase-Shawmut Company Electric fuse and process of manufacturing the same
ZA807349B (en) * 1979-12-03 1981-11-25 Beswick Kenneth E Ltd Method of manufacturing electrical cartridge fuselinks and fuselinks manufactured by the method
NL190652C (nl) * 1980-09-30 1994-06-01 Soc Corp Smeltelement voor toepassing in elektrische smeltveiligheden.
EP0094988A1 (en) * 1982-05-13 1983-11-30 Littelfuse-Olvis A.G. Electrical cartridge fuselinks and a method of manufacturing same
DE69116976T2 (de) * 1990-10-18 1996-10-02 Sumitomo Electric Industries Schmelzleiter
CN1034892C (zh) * 1994-10-28 1997-05-14 佘秀月 保险丝组装机
US9421405B1 (en) * 2013-03-18 2016-08-23 Williamsrdm, Inc. Stovetop fire extinguisher initiator with fuse device and method
FR3124118A1 (fr) 2021-06-21 2022-12-23 Psa Automobiles Sa Systeme de gestion thermique d’elements d’un vehicule

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB777125A (en) * 1954-06-04 1957-06-19 British Insulated Callenders A fuse arrangement primarily for use in electric capacitor installations
US2864917A (en) * 1954-12-23 1958-12-16 Edward V Sundt Short-time delay fuse
US3614699A (en) * 1970-08-10 1971-10-19 Mc Graw Edison Co Protector for electric circuits

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2412712A (en) * 1942-07-27 1946-12-17 Line Material Co Method of assembling fuse links
US2493434A (en) * 1946-03-21 1950-01-03 Joslyn Mfg And Supply Company Method of manufacturing fuse links

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB777125A (en) * 1954-06-04 1957-06-19 British Insulated Callenders A fuse arrangement primarily for use in electric capacitor installations
US2864917A (en) * 1954-12-23 1958-12-16 Edward V Sundt Short-time delay fuse
US3614699A (en) * 1970-08-10 1971-10-19 Mc Graw Edison Co Protector for electric circuits

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2308190A1 (fr) * 1975-04-16 1976-11-12 San O Ind Co Fusible miniature a retard
FR2309969A1 (fr) * 1975-05-02 1976-11-26 San O Ind Co Composant electrique et son application a un fusible a retard miniaturise
US4189696A (en) * 1975-05-22 1980-02-19 Kenneth E. Beswick Limited Electric fuse-links and method of making them
US4122426A (en) * 1976-02-03 1978-10-24 San-O Industrial Corp. Time-lag fuse
US4297666A (en) * 1978-02-03 1981-10-27 Wickmann Werke Ag Slow-blowing fuse using zinc-manganese alloy link
DE2901423A1 (de) * 1978-02-03 1979-08-09 Wickmann Werke Ag Schmelzsicherung
US4293836A (en) * 1979-07-11 1981-10-06 San-O Industrial Co., Ltd. Electrical fuse with an improved fusible element
US4369421A (en) * 1980-07-18 1983-01-18 Christian Felsch Safety device with delay
EP0046392A2 (en) * 1980-08-18 1982-02-24 Rte Corporation Full range current limiting fuse
EP0046392A3 (en) * 1980-08-18 1982-07-21 Rte Corporation Full range current limiting fuse
US4445106A (en) * 1980-10-07 1984-04-24 Littelfuse, Inc. Spiral wound fuse bodies
EP0116723A1 (en) * 1983-02-11 1984-08-29 Littelfuse-Olvis A.G. Electrical cartridge fuselinks and a method of manufacturing same
US4517544A (en) * 1983-10-24 1985-05-14 Mcgraw-Edison Company Time delay electric fuse
US5130688A (en) * 1988-11-21 1992-07-14 Littlefuse Tracor B.V. Fuse
US5736919A (en) * 1996-02-13 1998-04-07 Cooper Industries, Inc. Spiral wound fuse having resiliently deformable silicone core

Also Published As

Publication number Publication date
NL7013620A (xx) 1972-03-17
DE2145462A1 (de) 1972-03-16
FR2106538A1 (xx) 1972-05-05
CH536025A (de) 1973-04-15
DE2145462B2 (de) 1977-02-03
BE772443A (nl) 1972-03-10
SE383802B (sv) 1976-03-29
FR2106538B1 (xx) 1975-07-18
GB1304629A (xx) 1973-01-24
US3885303A (en) 1975-05-27
NL142815B (nl) 1974-07-15

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AS Assignment

Owner name: BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIA

Free format text: SECURITY INTEREST;ASSIGNOR:TRACOR HOLDINGS, INC., TRACOR, INC., AND OTHERS INDICATED ON SCHEDULE SA;REEL/FRAME:005317/0726

Effective date: 19891030

AS Assignment

Owner name: TRACOR, INC.

Free format text: RELEASED BY SECURED PARTY;ASSIGNOR:BANK OF AMERICA NATIONAL TRUST AND SAVINGS ASSOCIATION;REEL/FRAME:005953/0942

Effective date: 19911227