US3646322A - Electric resistance heating cable - Google Patents

Electric resistance heating cable Download PDF

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Publication number
US3646322A
US3646322A US103978A US3646322DA US3646322A US 3646322 A US3646322 A US 3646322A US 103978 A US103978 A US 103978A US 3646322D A US3646322D A US 3646322DA US 3646322 A US3646322 A US 3646322A
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US
United States
Prior art keywords
cable
wire
length
per unit
heating
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Expired - Lifetime
Application number
US103978A
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English (en)
Inventor
Bernardus Willebrordu Speekman
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US Philips Corp
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US Philips Corp
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Publication date
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Publication of US3646322A publication Critical patent/US3646322A/en
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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/40—Heating elements having the shape of rods or tubes
    • H05B3/54—Heating elements having the shape of rods or tubes flexible
    • H05B3/56—Heating cables

Definitions

  • the present invention relates generally to electric resistance heating cables, and more particularly to a cable having a flexible core of electrically insulating material, a heating wire wound helically around this core and extending throughout the length of the cable and a covering of electrically insulating material.
  • the cable is divided into at least two groups of alternating sectors extending in the longitudinal direction of the cable. These sectors assume different temperatures during use of the cable.
  • a cable of this kind is known from German Pat. specification No. 820,943.
  • the heating wire in the sectors which assume a comparatively low temperature during use is wound having a greater pitch than that in the sectors which assume a comparatively high temperature during use.
  • Such a cable may be obtained by passing the core continuously in one direction through a winding device and to cause this device to perform a forward and backward movement along the core at the areas where layers of heating wire are to be wound one on top of the other.
  • a fixing winding point is used and the core is moved forward and backward when layers of heating wire are to be wound one on top of the other.
  • An object of the present invention is to provide an electric resistance heating cable which may be manufactured without the need of specially equipped winding machines for this purpose.
  • an electric resistance heating cable satisfying this condition is characterized in that the heating wire is provided with sections having a comparatively high resistance per unit of length alternated by sections having a comparatively low resistance per unit of length.
  • Such a heating wire may consist of, for example, a wire having sections of the same material of alternately small and large diameter, or of sections having a different conductivity and being cross-connected together by means of welding or by soft or hard soldering.
  • a preferred form of heating wire is one having a comparatively high resistance per unit of length and which is provided at regular distances with envelopes having a comparatively low resistance per unit of length and extending in the longitudinal direction of the wire.
  • envelopes having a comparatively low resistance per unit of length are prevented.
  • silver, copper, gold and aluminum may be used for this purpose.
  • a wire in which the envelope surround the wire completely cylindrically may, however, be manufactured in a simple manner by a number of different methods. This case it is possible to start, for example, from a thick wire of a material having a high specific resistance, for example, a wire of nickel which is slid into a fitting cylinder of a material having a low specific resistance such as copper.
  • the cylinder encloses the wire throughout its length. Subsequently the diameter of the assembly is brought to the desired size by means of swaging and drawing, whereafter parts of the copper covering are etched away at regular distances.
  • An aqueous solution of FeCl or CuCl may be used as an etchant. Such etchants are known.
  • the parts of the copper covering not to be etched away may be protected from the etchant by providing these parts with a resist as a protection against the etchant, for example, a photoresist. It is alternatively possible to contact the etchant with those parts of the wire where the copper covering must be etched away. To this end the wire is wound on a coil and the coil is partly immersed into the etchant.
  • envelopes of better conducting material are provided only on certain parts of the resistance wire.
  • the parts of the wire not to be coated with better conducting material may be provided with a resist, for example, by -means of a photochemical method.
  • the uncovered parts of the wire are provided with an envelope of electrically conducting material. This may be effected, for example, by means of electrolysis.
  • the core of the cable may consist of any electrically insulating organic or inorganic material which is resistant to the temperatures occurring during use of the cable.
  • the core may have a single or composite structure and may comprise, for example, polyvinylchloride, silicon rubber, nylon, glass fiber, asbestos fiber, polytetrafluoroethylene and polyfluoroethylene propylene.
  • a central conductor may be present within the core so that contact can be established at one end of the cable, the central conductor is then connected to the heating wire at the other end of the cable.
  • the heating wire may in principle comprise any electrically conducting material.
  • a material having a high positive temperature coefficient of the specific resistance is preferably used (0.002 or more per C.), for example, nickel, copper.
  • 0.002 or more per C. for example, nickel, copper.
  • the heating wire When using copper on a heating wire consisting of another metal such as nickel, a slow oxidation from the ends of the copper envelope takes place during use if the parts of the heating wire not covered with copper reach a temperature of several hundred degrees centigrade. As a result, the copper envelope becomes increasingly shorter and hence the sectors of comparatively low temperature become increasingly smaller. This may be avoided by providing the heating wire with an oxidationresistant envelope of a metal, metal alloy or an oxide. It was found in practice that a thin nickel film of several microns thick was satisfactory for this purpose. Such an envelope is not necessary if instead of copper a noble metal is used such as gold or a metal which is coated with a protective oxide film such as aluminum.
  • the outer covering of the cable may consist of organic or inorganic materials which are known for this purpose. In principle the same materials may be used as those which are suitable for the core.
  • the cable may be obtained by passing the core, which will generally have a circular cross section, continuously in one direction through a winding device.
  • the core wound with resistance wire is subsequently provided with an outer covering, for example, by winding and/or pleating it with glass or asbestos fibers or rayon or cotton, or by passing it through an extrusion device by which the cable is provided with a synthetic resin covering.
  • the outer covering may optionally consist of a plurality of apertured bodies of ceramic material.
  • a marking device may be coupled to a device suitable for this purpose.
  • Cables according to the invention may be used in devices where heat is to be generated locally while the temperature of intermediate parts and connecting points are not to increase.
  • Cables according to the invention may be used, for example, in heaters for hair curlers in principle consisting of a plurality of hollow cylinders or fingers" to be heated which project from a bottom plate onto which the hair curlers can be slid.
  • the sectors of the cable which reach a high temperature during use are accommodated in the fingers while the parts which remain comparatively cold are provided in the bottom plate.
  • Cables according to the invention may alternatively be used in defrosters for refrigerators.
  • cables according to the invention may be used in electrically heatable clothing, coffeemakers and for the purpose of heating rooms.
  • FIG. 1 shows in a side view a wire which is provided at regular distances with better conducting envelopes.
  • FIG. 2 is a cross section of a wire which is provided at regular distances with better conducting envelopes and is subsequently provided throughout its length with a layer resistant to oxidation at high temperatures.
  • FIG. 3 shows a cable partly in cross section and with the outer covering removed provided with a wire according to FIG. 2.
  • the heating wire according to FIG. 1 consists of a core 1 of nickel having a diameter of 0.18 mm. and a resistance per meter of 4 ohms. Envelopes of copper are provided at regular distances over a length of 60 cm., the total diameter of the wire at this area being 0.285 mm. The resistance per meter of the covered wire is 0.4 ohm. The uncovered parts have a length of I meter. A cable may be obtained with this wire whose heating sectors reach a temperature of 400 C. when loaded and these sectors are flanked by sectors which reach a tem erature of only C.
  • FIG. 2 a preferred embodiment is shown in which the heating wire is provided with an oxidation resistant covering 3 of nickel which extends throughout the length of the wire.
  • This nickel covering may have a thickness of, for example, IO um. and does not essentially change the electrical properties of the heating wire.
  • F IG. 3 shows an embodiment of a cable according to the invention.
  • the heating wire 5 is wound on a core of glass fiber 4.
  • the assembly is enveloped by a glass fiber covering 6.
  • the cable according to the invention has inter alia the following advantages as compared with the known constructions:
  • the cable has a simple structure and as a result fewer rejects occur during manufacture of the cable.
  • the heating wire Before the heating wire is wound on the core of the cable it can be determined whether the used heating wire has any faults. When maintaining the pitch accurately during winding, there is little risk of the cable being unsatisfacto ry in an electrical respect after checking the heating wire.
  • the cable is less stiff than cables in which the heating wire is located in some areas in different layers one on top of the other or in which metal strips are provided in some areas along the cable between the heating wire and the core.
  • the cable can be used for a longer period than cables in which a number of turns of the heating wire are short circuited by metal strips and the like.
  • An electric redistance heating cable comprising a flexible core of electrically insulating material, a heating wire wound helically around said core and extending throughout the length of the cable and a covering of electrically insulating material, the cable being divided into at least two groups of alternating sectors extending in the longitudinal direction of the cable, which sectors assume mutually different temperatures during use of the cable, said heating wire comprising sections having a comparatively high resistance per unit of length al ternated by sections having a comparatively low resistance per unit of length.
  • heating wire comprises a wire having a comparatively high resistance per unit of length which is provided at regular distances with envelopes having a comparatively low resistance per unit of length and extending in the longitudinally direction of the wire.
  • heating wire comprises a wire having a comparatively high resistance per unit of length which is provided at regular distances with envelopes having a comparatively low resistance per unit of length and extending in the longitudinal direction of the wire, and further comprising an envelope extending throughout the length of the wire comprising a material which is still resistant to oxidation at the highest temperature which is reached during operation of the cable.

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  • Resistance Heating (AREA)
US103978A 1970-02-13 1971-01-05 Electric resistance heating cable Expired - Lifetime US3646322A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7002052A NL7002052A (no) 1970-02-13 1970-02-13

Publications (1)

Publication Number Publication Date
US3646322A true US3646322A (en) 1972-02-29

Family

ID=19809318

Family Applications (1)

Application Number Title Priority Date Filing Date
US103978A Expired - Lifetime US3646322A (en) 1970-02-13 1971-01-05 Electric resistance heating cable

Country Status (10)

Country Link
US (1) US3646322A (no)
AT (1) AT300143B (no)
BE (1) BE762906A (no)
CA (1) CA925914A (no)
CH (1) CH519837A (no)
DE (1) DE2105572A1 (no)
ES (1) ES388162A1 (no)
FR (1) FR2078526A5 (no)
GB (1) GB1309515A (no)
NL (1) NL7002052A (no)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4125761A (en) * 1974-10-08 1978-11-14 Churchill John W Bilateral heater unit
US4564745A (en) * 1984-02-24 1986-01-14 Geant Entrepeneur Electrique Ltee Pre-cast heating panel
US4816649A (en) * 1986-10-29 1989-03-28 Hew-Kabel Heinz Eilentropp Kg Flexible heating assembly
US5060287A (en) * 1990-12-04 1991-10-22 Shell Oil Company Heater utilizing copper-nickel alloy core
US5412181A (en) * 1993-12-27 1995-05-02 The B. F. Goodrich Company Variable power density heating using stranded resistance wire
US6002117A (en) * 1998-03-10 1999-12-14 Pak; Il Young Electric heating cord with non-heating core-conducting element and reduced EMF emissions
US6153856A (en) * 1997-01-21 2000-11-28 Lee; Myoung Jun Low magnetic field emitting electric blanket
US6175098B1 (en) * 1998-10-31 2001-01-16 Solco Biomedical Co., Ltd. Plane heating element without electromagnetic waves and a manufacturing method thereof
US6226450B1 (en) 1997-01-21 2001-05-01 Myoung Jun Lee Electric field shielding apparatus
US6300597B1 (en) 1997-01-21 2001-10-09 Myoung Jun Lee Electromagnetic field shielding electric heating pad
US20090260852A1 (en) * 2008-02-29 2009-10-22 Fort Wayne Metals Research Products Corporation Alternating core composite wire
US20100237057A1 (en) * 2006-01-18 2010-09-23 Wik Far East, Ltd Resistance Heating Element For a Hair Styling Device and a Hair Styling Device Equipped With Said Resistance Heating Element
EP2575409A1 (de) * 2011-09-29 2013-04-03 LEONI Kabel Holding GmbH Heizkordel sowie Heizvorrichtung mit einer Heizkordel
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US20160016495A1 (en) * 2013-01-15 2016-01-21 Kongsberg Automotive Ab Seat assembly having heating element providing electrical heating of variable temperature along a predetermined path to a zone

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19851920A1 (de) * 1998-11-11 2000-05-18 Eilentropp Kg Elektrisches Heizkabel
CN104619055B (zh) * 2014-12-17 2016-05-11 东南大学 一种真空内局部加热方法
DE112015006557T5 (de) 2015-07-01 2018-03-15 Kongsberg Automotive Ab Elektrische Heizanordnung
CN107810659B (zh) * 2015-07-01 2021-09-28 康斯博格汽车股份公司 电加热元件
CN107606860A (zh) * 2017-09-07 2018-01-19 浙江金丝通科技股份有限公司 制冷设备的化霜装置及方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE290451C (no) *
US3461275A (en) * 1968-01-26 1969-08-12 Pyrotel Corp Infrared quartz heater

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE290451C (no) *
US3461275A (en) * 1968-01-26 1969-08-12 Pyrotel Corp Infrared quartz heater

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4125761A (en) * 1974-10-08 1978-11-14 Churchill John W Bilateral heater unit
US4564745A (en) * 1984-02-24 1986-01-14 Geant Entrepeneur Electrique Ltee Pre-cast heating panel
US4816649A (en) * 1986-10-29 1989-03-28 Hew-Kabel Heinz Eilentropp Kg Flexible heating assembly
US5060287A (en) * 1990-12-04 1991-10-22 Shell Oil Company Heater utilizing copper-nickel alloy core
US5412181A (en) * 1993-12-27 1995-05-02 The B. F. Goodrich Company Variable power density heating using stranded resistance wire
US6226450B1 (en) 1997-01-21 2001-05-01 Myoung Jun Lee Electric field shielding apparatus
US6153856A (en) * 1997-01-21 2000-11-28 Lee; Myoung Jun Low magnetic field emitting electric blanket
US6300597B1 (en) 1997-01-21 2001-10-09 Myoung Jun Lee Electromagnetic field shielding electric heating pad
US6002117A (en) * 1998-03-10 1999-12-14 Pak; Il Young Electric heating cord with non-heating core-conducting element and reduced EMF emissions
US6175098B1 (en) * 1998-10-31 2001-01-16 Solco Biomedical Co., Ltd. Plane heating element without electromagnetic waves and a manufacturing method thereof
US20100237057A1 (en) * 2006-01-18 2010-09-23 Wik Far East, Ltd Resistance Heating Element For a Hair Styling Device and a Hair Styling Device Equipped With Said Resistance Heating Element
US20090260852A1 (en) * 2008-02-29 2009-10-22 Fort Wayne Metals Research Products Corporation Alternating core composite wire
US7989703B2 (en) 2008-02-29 2011-08-02 Fort Wayne Metals Research Products Corporation Alternating core composite wire
EP2575409A1 (de) * 2011-09-29 2013-04-03 LEONI Kabel Holding GmbH Heizkordel sowie Heizvorrichtung mit einer Heizkordel
US20160016495A1 (en) * 2013-01-15 2016-01-21 Kongsberg Automotive Ab Seat assembly having heating element providing electrical heating of variable temperature along a predetermined path to a zone
US9457702B2 (en) * 2013-01-15 2016-10-04 Kongsberg Automotive Ab Seat assembly having heating element providing electrical heating of variable temperature along a predetermined path to a zone
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US10264629B2 (en) * 2013-05-30 2019-04-16 Osram Sylvania Inc. Infrared heat lamp assembly

Also Published As

Publication number Publication date
NL7002052A (no) 1971-08-17
FR2078526A5 (no) 1971-11-05
GB1309515A (en) 1973-03-14
DE2105572A1 (de) 1971-08-19
ES388162A1 (es) 1974-01-01
AT300143B (de) 1972-07-10
CA925914A (en) 1973-05-08
BE762906A (fr) 1971-08-12
CH519837A (de) 1972-02-29

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