US3757086A - Electrical heating cable - Google Patents

Electrical heating cable Download PDF

Info

Publication number
US3757086A
US3757086A US00295228A US3757086DA US3757086A US 3757086 A US3757086 A US 3757086A US 00295228 A US00295228 A US 00295228A US 3757086D A US3757086D A US 3757086DA US 3757086 A US3757086 A US 3757086A
Authority
US
United States
Prior art keywords
low
resistance
foil
wires
strips
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
US00295228A
Inventor
W Indoe
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.)
Individual
Original Assignee
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
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3757086A publication Critical patent/US3757086A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00Ohmic-resistance heating
    • H05B3/40Heating elements having the shape of rods or tubes
    • H05B3/54Heating elements having the shape of rods or tubes flexible
    • H05B3/56Heating cables

Definitions

  • ABSTRACT An electrical heating cable having at least two lowresistance current-carrying wires and a high-resistance, heating wire spirally wound about the current-carrying wires; in one embodiment, the current-carrying wires are bared at spaced intervals so that the high-resistance wire makes electrical contact at the bared points with one of the current-carrying wires at each interval. In another embodiment, a plurality of copper foil wraps surrounds both insulated, current-carrying wires at spaced intervals and the high-resistance,heating wire is spirally wound over the current-carryingvvire's and the copper foil wraps.
  • a staple is driven through the insulation and one of the current-carrying wires at each interval so that electrical connection is made between the current-carrying wire and the heating wire at that interval;
  • the construction permits the user to cut the cable to any length and still maintain the same current flow in any given length for the same applied voltage.
  • the invention relates to electrical heating cables which are formed in a continuous length and which may be cut to any desired length while maintaining constant current flow through each heating section for a given applied voltage.
  • Prior art heating cables and tapes which are used for transferring heat from the cable to pipes or other devices, generally utilize special connectors and are generally designed and manufactured to a specific length. When one of these prior art cables is too long for the particular installation and it is cut to size, the current in the heating element increases for a given applied voltage.
  • the invention comprises at least two, current-carrying wires which are insulted from each other and have the insulation removed at predetermined, spaced points along the wires.
  • a spirally wound heater wire surrounds the insulated, current-carrying wires and makes electrical contact with the current-carrying wires at the bared, noninsulated points. The bared points are spaced so that when electrical connection is made to two of the current-carrying wires and voltage is applied, current flows in the heating wire.
  • copper foil wraps surround the insulated, current-carrying wires at spaced intervals and a staple is driven through the insulation surrounding one of the current-carrying wires so that electrical contact is made between the spirally wound heater wire and the current-carrying wire at that point.
  • FIG. 1 is a plan view of one embodiment of a heating cable of the invention having two current-carrying wires;
  • FIG. 2 is a simplified, schematic diagram showing the electrical circuit obtained when using the embodiment of FIG. 1;
  • FIG. 3 is a view similar to that of FIG. 1 of a three conductor heating cable of the invention.
  • FIG. 4 is a simplified, schematic diagram showing an electrical circuit which may be obtained when using the embodiment of FIGURE 3;
  • FIG. 5 is a view similar to that of FIG. 1 of a further embodiment of the invention.
  • FIG. 6 is an enlarged sectional view taken along lines 6--6 of FIG. 5, viewed in the direction of the arrows;
  • FIG. 7 is a view similar to that of FIG. 5 of a three conductor heating cable of the invention.
  • Cable 10 designates a twowire cable of the invention.
  • Cable 10 (FIG. 1) is seen to comprise a pair of low-resistance wires 12 and 14, covered respectively with an insulating cover 16 and 18, a spirally wound heater wire 20 of relatively high resistance and an outer insulating jacket 26.
  • the insulating covers 16 and 18 and the outer insulating jacket 26 may be formed of polytetrafluorine ethylene, polyvinyl chloride or any similar flexible plastic which will remain flexible and intact throughout the temperature range to which the cable will normally be subjected.
  • Wires 12 and 14 are bared of insulation at points 22 and 24, respectively, so that electrical contact is made with heater wire 20 at those points.
  • FIG. 2 is a simplified schematic diagram of a circuit using the cable of FIG. 1.
  • a source of power 30 is connected to wires 12 and 14 which are of low resistance and carry the current.
  • the applied voltage across the terminals 32 is constant and the current flow in each section of heating wire 20, namely, 20l 202...20-n, also is constant.
  • each section produces the same heating effect regardless of the number of sections being used. The user is therefore able to make a good, efficient installation and cut off any excess without affecting the efficiency of the various heating sections.
  • the cable of the invention is ideal for field installation around pipe lines or for burial in the ground since a long continuous length can be cut to the desired length without affecting the heating efficiency adversely.
  • the cable of the invention is applied to a pipe, it is wound around the pipe and then covered with a heat transfer cement to facilitate transfer of heat from the cable to the pipe.
  • Cable 40 (FIG. 3) is seen to comprise electrical, current-carrying wires 42, 44 and 46, which are insulated from each other by insulating coverings 48, 50 and 52, respectively.
  • a heating wire 54 is spirally wound about the three wires and makes contact with the wires at bared points 56, 58 and 60. The bared points are spaced apart for predetermined distances to keep the resistance between points at the proper value.
  • the combination is covered by an outer insulation 55 and, if desired, by a ground shield 62.
  • cable 40 The materials used for the construction of cable 40 are the same as those used for cable 10. Both cables 10 and 40 are shown untwisted but cables of the invention will normally be made with the current-carrying wires twisted together to simplify manufacture and maintain the proper constructional configuration.
  • FIG. 4 is a schematic diagram of one possible electric circuit which may be used with the cable 40.
  • Power source 64 is a three-phase supply and the cable is connected to terminals 66.
  • the applied voltage across each pair of terminals 66 produces current flow in the resistances connected across those terminals.
  • the voltage applied across the terminals 66 which are connected to wires 42 and 44, produces heating in sections 54-1, 544...54-n.
  • voltage applied across the terminals 66, which are connected to wires 44 and 46 produces heating in sections 54-2, 54-5...- 54-p and that applied across the terminals 66, which are connected to wires 46 and 42, produces heating in sections 54-3, 54-6...54-q.
  • cable 40 Operation and installation of cable 40 is similar to that for cable 10. It can readily be seen that the same construction may also be used for a four wire system and in other configurations.
  • Cable 70 (FIGS. and 6) is seen to comprise a pair of low resistance current-carrying wires 72 and 74 which are insulated from each other and from the surrounding environment by an insulator 76.
  • a first plurality of thin, conductive foil wraps or strips 80 of copper, silver or similar metallic material is wrapped at spaced intervals around insulator 76 and a second plurality of thin conductive foil wraps or strips 80 is wrapped at spaced intervals around insulator 76.
  • the two pluralities of foil strips 80 and 80 are interspersed so that each foil strip 80 has a corresponding foil strip 80' adjacent thereto.
  • Electrically conductive staples 82 are driven through the insulator 76, overlying strips 80 and into wire 72 so that electrical contact is made between each conductive foil strip 80 and wire 72.
  • electrically conductive staples 84 are driven through insulator 76, overlying strips 80' and into wire 74 so that electrical contact is made between each conductive foil strip 80 and wire 74.
  • a high resistance heating wire 78 is spirally wound along the length of cable 70 so that it makes electrical contact through the foil strips 80 and the staples 82 with wire 72 and through the foil strips 80' and the staples 84 with wire 74.
  • An outer insulating cover 86 is used tp protect and insulate the cable 70.
  • cable 70 The electrical circuit and operation of cable 70 are the same as those of cable 10.
  • FIG. 7 illustrates a three conductive cable 90 which comprises low resistance, current-carrying wires 92, 94 and 96, spirally wound, high-resistance, heating wire 98 and outer insulating cover 108. Electrical contact is made between wire 92 and heating wire 98 by conductive foil wrap 100 and electrically conductive staple 102. Similarly, connection is made between wire 94 and heating wire 98 by conductive foil wrap 100' and electrically conductive staple 104 and between wire 96 and heating wire 98 by conductive foil wrap 100' and electrically conductive staple 106.
  • the circuit of FIG. 4 is applicable to the embodiment of FIG. 7 and the operation of cable 90 is the same as that of cable 40.
  • the materials used for the wires, both currentcarrying and heating, and the insulating covers are the same for cables 70 and 90 as for cables and 40.
  • Conductive shields 87 and 109 which are similar to shields 28 and 62, may be used in cables 70 and 90, respectively.
  • An electrical heating cable which maintains the same current flow for any given applied voltage in each section of predetermined length regardless of the total length of the cable comprising:
  • first and second strips of conductive metallic foil being spaced from one another and being located alternately along the length of the low-resistance wires such that each first strip has a corresponding next-consecutive second strip adjacent thereto;
  • V a high resistance wire wound spirally over the insulator and the first and second strips of foil along the length of the low-resistance wires so that electrical contact is made between the foil strips and the high-resistance wire;
  • each first staple overlying a corresponding first foil strip and extending through the insulator to make electrical contact between said first foil strip and the first low-resistance wire;
  • each second staple overlying a corresponding second foil strip and extending through the insulator to make electrical contact between said second foil strip and the second lowresistance wire, whereby current will flow in the high-resistance wire to produce heat therefrom when an electric voltage is applied across the low resistance wires;
  • an outer insulating covering surrounding the combination of the spirally wound, high-resistance wire and the low-resistance wires.
  • the invention of claim 1 including an outer, electrically conductive shield surrounding the outer insulated covering.
  • first, second and third strips of conductive metallic foil being spaced from one another and being located along the length of the low-resistance wires such that consecutive first and second adjacent strips have a corresponding next-consecutive third strip adjacent thereto;
  • the invention of claim 3 including an outer, electhrough the insulator to make electrical Contact betrically conductive shield surrounding the outer insutween said third foil strip and the third lowlated covering.

Abstract

An electrical heating cable having at least two low-resistance current-carrying wires and a high-resistance, heating wire spirally wound about the current-carrying wires; in one embodiment, the current-carrying wires are bared at spaced intervals so that the high-resistance wire makes electrical contact at the bared points with one of the current-carrying wires at each interval. In another embodiment, a plurality of copper foil wraps surrounds both insulated, current-carrying wires at spaced intervals and the high-resistance, heating wire is spirally wound over the current-carrying wires and the copper foil wraps. A staple is driven through the insulation and one of the current-carrying wires at each interval so that electrical connection is made between the current-carrying wire and the heating wire at that interval. The construction permits the user to cut the cable to any length and still maintain the same current flow in any given length for the same applied voltage.

Description

United States Patent [1 1 Indoe [451 Sept. 4, 1973 ELECTRICAL HEATING CABLE [76] inventor: William J. Indoe, 45 Oak St.,
Allendale, NJ. 07401 221 Filed: Oct. 5, 1972 21 Appl. No.: 295,228
Related US. Application Data [63] Continuation-impart of Ser. No. 199,472, Nov. 17,
1971, abandoned.
2,494,589 1/1950 Sletner 3,341,690 9/1967 Commins... 219/528 3,454,747 7/1969 Hart 219/549 3,567,906 3/1971 Hurko 219/464 3,657,520 4/1972 Ragault 219/553 FOREIGN PATENTS OR APPLICATIONS 116,448 10/1946 Sweden 338/214 Primary Examinervolodymyr Y. Mayewsky Attorney-Cyrus D. Samuelson et al.
[5 7] ABSTRACT An electrical heating cable having at least two lowresistance current-carrying wires and a high-resistance, heating wire spirally wound about the current-carrying wires; in one embodiment, the current-carrying wires are bared at spaced intervals so that the high-resistance wire makes electrical contact at the bared points with one of the current-carrying wires at each interval. In another embodiment, a plurality of copper foil wraps surrounds both insulated, current-carrying wires at spaced intervals and the high-resistance,heating wire is spirally wound over the current-carryingvvire's and the copper foil wraps. A staple is driven through the insulation and one of the current-carrying wires at each interval so that electrical connection is made between the current-carrying wire and the heating wire at that interval; The construction permits the user to cut the cable to any length and still maintain the same current flow in any given length for the same applied voltage.
4 Claims, 7 Drawing Figures l lllllll "III/III]. A. I ill/Ill PMENTEU 3E? 41975 SHEET 2 [1F 2 v& s
lll L l I I l I I ll MEI s Q. N
ELECTRICAL HEATING CABLE This application is a continuation-in-part of my copending application Ser. No. 199,472, filed Nov. I7, 1971, now abandoned.
The invention relates to electrical heating cables which are formed in a continuous length and which may be cut to any desired length while maintaining constant current flow through each heating section for a given applied voltage.
Prior art heating cables and tapes, which are used for transferring heat from the cable to pipes or other devices, generally utilize special connectors and are generally designed and manufactured to a specific length. When one of these prior art cables is too long for the particular installation and it is cut to size, the current in the heating element increases for a given applied voltage.
Accordingly it is an important object of the invention to provide a heating cable which, for a given applied voltage, maintains the same heating current in each section regardless of the length of the cable.
It is a further object of the invention to provide such a heating cable which has at least two low-resistance, current-carrying conductors and a heating wire wound spirally about the conductors.
It is a still further object of the invention to provide such a heating cable with two current-carrying conductors.
It is yet another object of the invention to provide such a heating cable with three current-carrying conductors.
It is a still further object of the invention to provide such a heating cable which is easy to install and is capable of high heat transfer to the object being heated.
These and other objects, advantages, features and uses will be apparent during the course of the following description when taken together with the accompanying drawing.
Broadly, the invention comprises at least two, current-carrying wires which are insulted from each other and have the insulation removed at predetermined, spaced points along the wires. A spirally wound heater wire surrounds the insulated, current-carrying wires and makes electrical contact with the current-carrying wires at the bared, noninsulated points. The bared points are spaced so that when electrical connection is made to two of the current-carrying wires and voltage is applied, current flows in the heating wire.
In another embodiment, copper foil wraps surround the insulated, current-carrying wires at spaced intervals and a staple is driven through the insulation surrounding one of the current-carrying wires so that electrical contact is made between the spirally wound heater wire and the current-carrying wire at that point.
In the accompanying drawing, forming a part hereof, and in which like numerals are employed to designate like parts throughout the same:
FIG. 1 is a plan view of one embodiment of a heating cable of the invention having two current-carrying wires;
FIG. 2 is a simplified, schematic diagram showing the electrical circuit obtained when using the embodiment of FIG. 1;
FIG. 3 is a view similar to that of FIG. 1 of a three conductor heating cable of the invention; FIG.
FIG. 4 is a simplified, schematic diagram showing an electrical circuit which may be obtained when using the embodiment of FIGURE 3;
FIG. 5 is a view similar to that of FIG. 1 of a further embodiment of the invention.
FIG. 6 is an enlarged sectional view taken along lines 6--6 of FIG. 5, viewed in the direction of the arrows; and
FIG. 7 is a view similar to that of FIG. 5 of a three conductor heating cable of the invention.
In the drawing wherein, for the purpose of illustration, there are shown preferred embodiments of the invention and wherein like numerals designate like parts throughout the same, the numeral 10 designates a twowire cable of the invention. Cable 10 (FIG. 1) is seen to comprise a pair of low- resistance wires 12 and 14, covered respectively with an insulating cover 16 and 18, a spirally wound heater wire 20 of relatively high resistance and an outer insulating jacket 26. The insulating covers 16 and 18 and the outer insulating jacket 26 may be formed of polytetrafluorine ethylene, polyvinyl chloride or any similar flexible plastic which will remain flexible and intact throughout the temperature range to which the cable will normally be subjected.
Under certain conditions, it is desirable to provide a shield 28 of woven conductive material to serve as a ground and to resist abrasion. Wires 12 and 14 are bared of insulation at points 22 and 24, respectively, so that electrical contact is made with heater wire 20 at those points.
FIG. 2 is a simplified schematic diagram of a circuit using the cable of FIG. 1. A source of power 30 is connected to wires 12 and 14 which are of low resistance and carry the current. The applied voltage across the terminals 32 is constant and the current flow in each section of heating wire 20, namely, 20l 202...20-n, also is constant. Thus, each section produces the same heating effect regardless of the number of sections being used. The user is therefore able to make a good, efficient installation and cut off any excess without affecting the efficiency of the various heating sections.
Some prior art, multiple section cables require special connector blocks to accomplish the desired electrical heating. Others require that each installation have a cable specially designed for a particular length. Clearly, the cable of the invention is ideal for field installation around pipe lines or for burial in the ground since a long continuous length can be cut to the desired length without affecting the heating efficiency adversely. Generally, when the cable of the invention is applied to a pipe, it is wound around the pipe and then covered with a heat transfer cement to facilitate transfer of heat from the cable to the pipe.
Cable 40 (FIG. 3) is seen to comprise electrical, current-carrying wires 42, 44 and 46, which are insulated from each other by insulating coverings 48, 50 and 52, respectively. A heating wire 54 is spirally wound about the three wires and makes contact with the wires at bared points 56, 58 and 60. The bared points are spaced apart for predetermined distances to keep the resistance between points at the proper value. The combination is covered by an outer insulation 55 and, if desired, by a ground shield 62.
The materials used for the construction of cable 40 are the same as those used for cable 10. Both cables 10 and 40 are shown untwisted but cables of the invention will normally be made with the current-carrying wires twisted together to simplify manufacture and maintain the proper constructional configuration.
FIG. 4 is a schematic diagram of one possible electric circuit which may be used with the cable 40. Power source 64 is a three-phase supply and the cable is connected to terminals 66. The applied voltage across each pair of terminals 66 produces current flow in the resistances connected across those terminals. For example, the voltage applied across the terminals 66, which are connected to wires 42 and 44, produces heating in sections 54-1, 544...54-n. Similarly, voltage applied across the terminals 66, which are connected to wires 44 and 46, produces heating in sections 54-2, 54-5...- 54-p and that applied across the terminals 66, which are connected to wires 46 and 42, produces heating in sections 54-3, 54-6...54-q.
Operation and installation of cable 40 is similar to that for cable 10. It can readily be seen that the same construction may also be used for a four wire system and in other configurations.
Cable 70 (FIGS. and 6) is seen to comprise a pair of low resistance current-carrying wires 72 and 74 which are insulated from each other and from the surrounding environment by an insulator 76. A first plurality of thin, conductive foil wraps or strips 80 of copper, silver or similar metallic material is wrapped at spaced intervals around insulator 76 and a second plurality of thin conductive foil wraps or strips 80 is wrapped at spaced intervals around insulator 76. The two pluralities of foil strips 80 and 80 are interspersed so that each foil strip 80 has a corresponding foil strip 80' adjacent thereto. Electrically conductive staples 82 are driven through the insulator 76, overlying strips 80 and into wire 72 so that electrical contact is made between each conductive foil strip 80 and wire 72. Similarly, electrically conductive staples 84 are driven through insulator 76, overlying strips 80' and into wire 74 so that electrical contact is made between each conductive foil strip 80 and wire 74. A high resistance heating wire 78 is spirally wound along the length of cable 70 so that it makes electrical contact through the foil strips 80 and the staples 82 with wire 72 and through the foil strips 80' and the staples 84 with wire 74. An outer insulating cover 86 is used tp protect and insulate the cable 70.
The electrical circuit and operation of cable 70 are the same as those of cable 10.
FIG. 7 illustrates a three conductive cable 90 which comprises low resistance, current-carrying wires 92, 94 and 96, spirally wound, high-resistance, heating wire 98 and outer insulating cover 108. Electrical contact is made between wire 92 and heating wire 98 by conductive foil wrap 100 and electrically conductive staple 102. Similarly, connection is made between wire 94 and heating wire 98 by conductive foil wrap 100' and electrically conductive staple 104 and between wire 96 and heating wire 98 by conductive foil wrap 100' and electrically conductive staple 106.
The circuit of FIG. 4 is applicable to the embodiment of FIG. 7 and the operation of cable 90 is the same as that of cable 40.
The materials used for the wires, both currentcarrying and heating, and the insulating covers are the same for cables 70 and 90 as for cables and 40. Conductive shields 87 and 109, which are similar to shields 28 and 62, may be used in cables 70 and 90, respectively.
While particular embodiments of the invention have been shown and described, it is apparent to those skilled in the art that modifications are possible without departing from the spirit of the invention or the scope of the subjoined claims.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.
1. An electrical heating cable which maintains the same current flow for any given applied voltage in each section of predetermined length regardless of the total length of the cable comprising:
first and second electrically conductive,
resistance wires in proximity with each other;
an electrical insulator surrounding each lowresistance wire and electrically insulating the lowresistance wires from one another;
a plurality of first strips of conductive metallic foil wound around the electrical insulator and the lowresistance wires therein and spaced therealong;
a plurality of second strips of conductive metallic foil wound around the electrical insulator and the lowresistance wires therein and spaced therealong;
said first and second strips of conductive metallic foil being spaced from one another and being located alternately along the length of the low-resistance wires such that each first strip has a corresponding next-consecutive second strip adjacent thereto;
a high resistance wire wound spirally over the insulator and the first and second strips of foil along the length of the low-resistance wires so that electrical contact is made between the foil strips and the high-resistance wire; V
a plurality of first staples, each first staple overlying a corresponding first foil strip and extending through the insulator to make electrical contact between said first foil strip and the first low-resistance wire;
a plurality of second staples, each second staple overlying a corresponding second foil strip and extending through the insulator to make electrical contact between said second foil strip and the second lowresistance wire, whereby current will flow in the high-resistance wire to produce heat therefrom when an electric voltage is applied across the low resistance wires; and
an outer insulating covering surrounding the combination of the spirally wound, high-resistance wire and the low-resistance wires.
2. The invention of claim 1 including an outer, electrically conductive shield surrounding the outer insulated covering.
3. The invention of claim 8 including:
a third electrically conductive, low-resistance wire in proximity with said first and second low-resistance wires and surrounded by said insulator;
a plurality of third strips of conductive metallic foil wound around the insulator and the low-resistance wires therein and spaced therealong, the highresistance wire being wound over the third strips of foil;
said first, second and third strips of conductive metallic foil being spaced from one another and being located along the length of the low-resistance wires such that consecutive first and second adjacent strips have a corresponding next-consecutive third strip adjacent thereto; and
low-
6 a third staple overlying a third foil strip and extending 4. The invention of claim 3 including an outer, electhrough the insulator to make electrical Contact betrically conductive shield surrounding the outer insutween said third foil strip and the third lowlated covering.
resistance wire. 1: It: k
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 347571086 immmialtw Inventor(s) Hj j 1; ,1 Indoe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 41,- "insulted' should read -insulated Column 1, line 67, "FIG." should be deleted Column 3, line 44, "tp" should read -to Column 3, line 57, "100'" should read -l00":-
Claim 3, line 1, "8" should read --l-- Signed andsealed this 29th day of January 1974.
(SEAL) Attest:
EDWARD M. FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents ORM PO-105O (10-69) USCOMM-DC 6037 6-1 69 5. GOVFRNMENT PRINTING OFFICE ll. 0-366-334, 2
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,757,0 5 Dated sgptgmbgz 4 1213 Inventor(s) Hjnjam Q, Infioe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1, line 41, "insulted'f should read -insulated-- Column 1, line 67, "FIG." should be deleted Column 3, line 44, "tp" should read -to-- Column 3, line 57, "100'" should read l00" Claim 3., line 1; "8" should read -l- Signed and-sealed this 29th day of January 1974;
(SEAL) Attest:
EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents ORM P0-10 USCOMM-DC scan-Pee I i S. GOV II NKINT PRINTING OFFICE I," 0"356'JJL

Claims (4)

1. An electrical heating cable which maintains the same current flow for any given applied voltage in each section of predetermined length regardless of the total length of the cable comprising: first and second electrically conductive, low-resistance wires in proximity with each other; an electrical insulator surrounding each low-resistance wire and electrically insulating the low-resistance wires from one another; a plurality of first strips of conductive metallic foil wound around the electrical insulator and the low-resistance wires therein and spaced therealong; a plurality of second strips of conductive metallic foil wound around the electrical insulator and the low-resistance wires therein and spaced therealong; said first and second strips of conductive metallic foil being spaced from one another and being located alternately along the length of the low-resistance wires such that each first strip has a corresponding next-consecutive second strip adjacent thereto; a high resistance wire wound spirally over the insulator and the first and second strips of foil along the length of the lowresistance wires so that electrical contact is made between the foil strips and the high-resistance wire; a plurality of first staples, each first staple overlying a corresponding first foil strip and extending through the insulator to make electrical contact between said first foil strip and the first low-resistance wire; a plurality of second staples, each second staple overlying a corresponding second foil strip and extending through the insulator to make electrical contact between said second foil strip and the second low-resistance wire, whereby current will flow in the high-resistance wire to produce heat therefrom when an electric voltage is applied across the low-resistance wires; and an outer insulating covering surrounding the combination of the spirally wound, high-resistance wire and the low-resistance wires.
2. The invention of claim 1 including an outer, electrically conductive shield surrounding the outer insulated covering.
3. The invention of claim 8 including: a third electrically conductive, low-resistance wire in proximity with said first and second low-resistance wires and surrounded by said insulator; a plurality of third strips of conductive metallic foil wound around the insulator and the low-resistance wires therein and spaced therealong, the high-resistance wire being wound over the third strips of foil; said first, second and third strips of conductive metallic foil being spaced from one another and being located along the length of the low-resistance wires such that consecutive first and second adjacent strips have a corresponding next-consecutive third strip adjacent thereto; and a third staple overlying a third foil strip and extending through the insulator to make electrical contact between said third foil strip and the third low-resistance wire.
4. The invention of claim 3 including an outer, electrically conductive shield surrounding the outer insulated covering.
US00295228A 1972-10-05 1972-10-05 Electrical heating cable Expired - Lifetime US3757086A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US29522872A 1972-10-05 1972-10-05

Publications (1)

Publication Number Publication Date
US3757086A true US3757086A (en) 1973-09-04

Family

ID=23136788

Family Applications (1)

Application Number Title Priority Date Filing Date
US00295228A Expired - Lifetime US3757086A (en) 1972-10-05 1972-10-05 Electrical heating cable

Country Status (2)

Country Link
US (1) US3757086A (en)
JP (1) JPS5230728B2 (en)

Cited By (52)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3859506A (en) * 1973-06-15 1975-01-07 Sola Basic Ind Inc Constant wattage heating element
US4001760A (en) * 1974-06-21 1977-01-04 Pyrotenax Of Canada Limited Heating cables and manufacture thereof
US4033028A (en) * 1974-06-21 1977-07-05 Pyrotenax Of Canada Limited Method of making heating cables
US4037083A (en) * 1976-05-05 1977-07-19 Leavines Joseph E High temperature parallel resistance pipe heater
US4072848A (en) * 1976-07-22 1978-02-07 Thermon Manufacturing Company Electrical heating cable with temperature self-limiting heating elements
US4100673A (en) * 1977-05-05 1978-07-18 Leavines Joseph E Method of making high temperature parallel resistance pipe heater
US4121093A (en) * 1975-11-29 1978-10-17 Heat Trace Limited Surface heating equipment
US4152577A (en) * 1976-06-23 1979-05-01 Leavines Joseph E Method of improving heat transfer for electric pipe heaters
FR2447127A1 (en) * 1979-01-16 1980-08-14 Beck Heinz V D HEATING PIPE WITH SPECIFIC THERMAL POWER
US4250400A (en) * 1979-11-19 1981-02-10 The Scott & Fetzer Company Flexible temperature self regulating heating cable
US4304044A (en) * 1979-11-19 1981-12-08 The Scott & Fetzer Company Method for forming self-regulating heat trace cable
WO1982001112A1 (en) * 1980-09-18 1982-04-01 Mfg Co Thermon Parallel-type heating cable and method of making same
EP0092406A2 (en) * 1982-04-16 1983-10-26 RAYCHEM CORPORATION (a Delaware corporation) Elongate electrical heating device and a system comprising such devices
EP0098253A1 (en) * 1982-06-24 1984-01-11 Kima Elprodukter Ab A heating cable and a method of making it
DE3233928A1 (en) * 1982-09-13 1984-03-15 HEW-Kabel Heinz Eilentropp KG, 5272 Wipperfürth Flexible electrical heating or temperature measuring element
FR2533101A1 (en) * 1982-09-13 1984-03-16 Eilentropp Hew Kabel FLEXIBLE ELECTRIC ELEMENT, CUTTING IN LENGTHS, FOR HEATING OR TEMPERATURE MEASUREMENT
US4453159A (en) * 1981-09-28 1984-06-05 Thermon Manufacturing Company Self-monitoring heat tracing system
US4459473A (en) * 1982-05-21 1984-07-10 Raychem Corporation Self-regulating heaters
US4574188A (en) * 1982-04-16 1986-03-04 Raychem Corporation Elongate electrical assemblies
US4582983A (en) * 1982-04-16 1986-04-15 Raychem Corporation Elongate electrical assemblies
US4593181A (en) * 1984-02-06 1986-06-03 Raychem Corporation Heating element having deformed buss bars
US4626664A (en) * 1984-02-15 1986-12-02 Flexwatt Corporation Electrical heating device
US4638150A (en) * 1984-07-19 1987-01-20 Raychem Corporation Modular electrical heater
US4659913A (en) * 1982-04-16 1987-04-21 Raychem Corporation Elongate electrical assemblies
FR2593014A1 (en) * 1986-01-16 1987-07-17 Pyrotenax Canada Ltd ELECTRIC CABLES AND PREFORMS TO MAKE THESE CABLES
US4733059A (en) * 1987-06-15 1988-03-22 Thermon Manufacturing Company Elongated parallel, constant wattage heating cable
US4791276A (en) * 1982-04-16 1988-12-13 Raychem Corporation Elongate electrical assemblies
DE3830296C1 (en) * 1988-09-02 1990-03-22 Monette Kabel- U. Elektrowerk Gmbh, 3550 Marburg, De Parallel-heating strip
EP0388990A2 (en) 1986-02-20 1990-09-26 RAYCHEM CORPORATION (a Delaware corporation) Method and articles employing ion exchange material
GB2236236A (en) * 1989-09-22 1991-03-27 Thermon Mfg Co Electric heating cable
US5245161A (en) * 1990-08-31 1993-09-14 Tokyo Kogyo Boyeki Shokai, Ltd. Electric heater
US5353209A (en) * 1991-08-09 1994-10-04 Roberto Foottit Electrical distribution and/or lighting system with continuous connection point
US5512732A (en) * 1990-09-20 1996-04-30 Thermon Manufacturing Company Switch controlled, zone-type heating cable and method
US5676872A (en) * 1994-12-27 1997-10-14 Bobinajes Nugar, S.L. Flexible heating element having a layer of fixing varnish
US5910266A (en) * 1997-05-28 1999-06-08 The B.F. Goodrich Company Helical electrical heater
US6005232A (en) * 1996-06-28 1999-12-21 Raychem Corporation Heating cable
CN1056263C (en) * 1995-12-17 2000-09-06 赵放 Alloy PTC parallel type electric heating strip
US6144018A (en) * 1993-02-08 2000-11-07 Heizer; Glenwood Franklin Heating cable
US6555787B1 (en) 2001-12-05 2003-04-29 Dekko Heating Technologies, Inc. Three conductor heating element
GB2390004A (en) * 2002-03-08 2003-12-24 Martin Cook Flexible heating element
US20050167134A1 (en) * 2004-02-02 2005-08-04 Philippe Charron Heating cable substantially free from electromagnetic field
US20050249556A1 (en) * 2004-05-10 2005-11-10 Robert Colbert Device for preventing dock piling or structure piling uplift
US20070075071A1 (en) * 2005-09-30 2007-04-05 Cardenas Carlos A Pipe heater
US20090283515A1 (en) * 2008-05-16 2009-11-19 Umesh Sopory Heating cable with a heating element positioned in the middle of bus wires
US20110074380A1 (en) * 2008-05-28 2011-03-31 Silveray Co., Ltd. Electric conduction pad and manufacturing method thereof
US7989740B2 (en) 2008-05-16 2011-08-02 Thermon Manufacturing Company Heating cable
CN102271430A (en) * 2010-06-03 2011-12-07 无锡恒业电热电器有限公司 High-temperature constant-power parallel-type electric heating strip
US20130140018A1 (en) * 2011-12-01 2013-06-06 Pablo Javier INVIERNO Heater cable for tubing in shale type hydrocarbon production wells exposed to high pressures and wells with annular space flooded eventually or permanently or a combination of both
WO2014173737A1 (en) * 2013-04-23 2014-10-30 Kima Heating Cable Ab Power controlled heating system
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
CN107197554A (en) * 2017-05-31 2017-09-22 泰州瑞侃电热电器有限公司 Carbon fiber parallel electric heat tracing band
WO2019166786A1 (en) * 2018-02-28 2019-09-06 Heat Trace Limited Electrical heating cable

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58199021A (en) * 1982-05-18 1983-11-19 Furuhata Teruo Smoke eliminating device
JPS5971599U (en) * 1982-11-04 1984-05-15 桜アルミ株式会社 heating cylinder
JPH04112480A (en) * 1990-08-31 1992-04-14 Tokyo Kogyo Boeki Shokai:Kk Electric heater cable

Cited By (76)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3859506A (en) * 1973-06-15 1975-01-07 Sola Basic Ind Inc Constant wattage heating element
US4001760A (en) * 1974-06-21 1977-01-04 Pyrotenax Of Canada Limited Heating cables and manufacture thereof
US4033028A (en) * 1974-06-21 1977-07-05 Pyrotenax Of Canada Limited Method of making heating cables
US4121093A (en) * 1975-11-29 1978-10-17 Heat Trace Limited Surface heating equipment
US4037083A (en) * 1976-05-05 1977-07-19 Leavines Joseph E High temperature parallel resistance pipe heater
US4152577A (en) * 1976-06-23 1979-05-01 Leavines Joseph E Method of improving heat transfer for electric pipe heaters
US4117312A (en) * 1976-07-22 1978-09-26 Thermon Manufacturing Company Self-limiting temperature electrical heating cable
US4072848A (en) * 1976-07-22 1978-02-07 Thermon Manufacturing Company Electrical heating cable with temperature self-limiting heating elements
US4100673A (en) * 1977-05-05 1978-07-18 Leavines Joseph E Method of making high temperature parallel resistance pipe heater
FR2447127A1 (en) * 1979-01-16 1980-08-14 Beck Heinz V D HEATING PIPE WITH SPECIFIC THERMAL POWER
DE2901446C2 (en) * 1979-01-16 1981-04-09 Beck, von der, Heinz, 8011 Baldham Heating cable with specific heating output
US4308448A (en) * 1979-01-16 1981-12-29 Beck Heinz V D Heating cable with a specific heating capacity
US4250400A (en) * 1979-11-19 1981-02-10 The Scott & Fetzer Company Flexible temperature self regulating heating cable
US4304044A (en) * 1979-11-19 1981-12-08 The Scott & Fetzer Company Method for forming self-regulating heat trace cable
US4345368A (en) * 1980-09-18 1982-08-24 Thermon Manufacturing Co. Parallel-type heating cable and method of making same
US4392051A (en) * 1980-09-18 1983-07-05 Thermon Manufacturing Company Parallel-type heating cable
WO1982001112A1 (en) * 1980-09-18 1982-04-01 Mfg Co Thermon Parallel-type heating cable and method of making same
US4453159A (en) * 1981-09-28 1984-06-05 Thermon Manufacturing Company Self-monitoring heat tracing system
US4574188A (en) * 1982-04-16 1986-03-04 Raychem Corporation Elongate electrical assemblies
EP0092406A2 (en) * 1982-04-16 1983-10-26 RAYCHEM CORPORATION (a Delaware corporation) Elongate electrical heating device and a system comprising such devices
EP0092406A3 (en) * 1982-04-16 1984-02-29 Raychem Corporation Elongate electrical assemblies
US4791276A (en) * 1982-04-16 1988-12-13 Raychem Corporation Elongate electrical assemblies
US4659913A (en) * 1982-04-16 1987-04-21 Raychem Corporation Elongate electrical assemblies
US4582983A (en) * 1982-04-16 1986-04-15 Raychem Corporation Elongate electrical assemblies
US4459473A (en) * 1982-05-21 1984-07-10 Raychem Corporation Self-regulating heaters
EP0098253A1 (en) * 1982-06-24 1984-01-11 Kima Elprodukter Ab A heating cable and a method of making it
FR2533101A1 (en) * 1982-09-13 1984-03-16 Eilentropp Hew Kabel FLEXIBLE ELECTRIC ELEMENT, CUTTING IN LENGTHS, FOR HEATING OR TEMPERATURE MEASUREMENT
US4523086A (en) * 1982-09-13 1985-06-11 Hew Kabel, Heinz Eilentropp Kg Flexible electrical thermal element
DE3233928A1 (en) * 1982-09-13 1984-03-15 HEW-Kabel Heinz Eilentropp KG, 5272 Wipperfürth Flexible electrical heating or temperature measuring element
US4593181A (en) * 1984-02-06 1986-06-03 Raychem Corporation Heating element having deformed buss bars
US4626664A (en) * 1984-02-15 1986-12-02 Flexwatt Corporation Electrical heating device
US4638150A (en) * 1984-07-19 1987-01-20 Raychem Corporation Modular electrical heater
FR2593014A1 (en) * 1986-01-16 1987-07-17 Pyrotenax Canada Ltd ELECTRIC CABLES AND PREFORMS TO MAKE THESE CABLES
EP0388990A2 (en) 1986-02-20 1990-09-26 RAYCHEM CORPORATION (a Delaware corporation) Method and articles employing ion exchange material
US4733059A (en) * 1987-06-15 1988-03-22 Thermon Manufacturing Company Elongated parallel, constant wattage heating cable
AU598429B2 (en) * 1987-06-15 1990-06-21 Thermon Manufacturing Company Elongated parallel, constant wattage heating cable
EP0295359A2 (en) * 1987-06-15 1988-12-21 Thermon Manufacturing Company Elongated parallel, constant wattage heating cable
EP0295359B1 (en) * 1987-06-15 1993-04-14 Thermon Manufacturing Company Elongated parallel, constant wattage heating cable
DE3830296C1 (en) * 1988-09-02 1990-03-22 Monette Kabel- U. Elektrowerk Gmbh, 3550 Marburg, De Parallel-heating strip
GB2236236A (en) * 1989-09-22 1991-03-27 Thermon Mfg Co Electric heating cable
FR2652477A1 (en) * 1989-09-22 1991-03-29 Thermon Mfg Co CUT TO LENGH HEATER CABLE.
US5245161A (en) * 1990-08-31 1993-09-14 Tokyo Kogyo Boyeki Shokai, Ltd. Electric heater
US5394507A (en) * 1990-08-31 1995-02-28 Tokyo Kogyo Boyeki Shokai, Ltd. Heated tube with a braided electric heater
US5512732A (en) * 1990-09-20 1996-04-30 Thermon Manufacturing Company Switch controlled, zone-type heating cable and method
US5353209A (en) * 1991-08-09 1994-10-04 Roberto Foottit Electrical distribution and/or lighting system with continuous connection point
US6144018A (en) * 1993-02-08 2000-11-07 Heizer; Glenwood Franklin Heating cable
US5676872A (en) * 1994-12-27 1997-10-14 Bobinajes Nugar, S.L. Flexible heating element having a layer of fixing varnish
CN1056263C (en) * 1995-12-17 2000-09-06 赵放 Alloy PTC parallel type electric heating strip
US6005232A (en) * 1996-06-28 1999-12-21 Raychem Corporation Heating cable
US5910266A (en) * 1997-05-28 1999-06-08 The B.F. Goodrich Company Helical electrical heater
US6555787B1 (en) 2001-12-05 2003-04-29 Dekko Heating Technologies, Inc. Three conductor heating element
GB2390004A (en) * 2002-03-08 2003-12-24 Martin Cook Flexible heating element
US20050167134A1 (en) * 2004-02-02 2005-08-04 Philippe Charron Heating cable substantially free from electromagnetic field
US20050249556A1 (en) * 2004-05-10 2005-11-10 Robert Colbert Device for preventing dock piling or structure piling uplift
US7635238B2 (en) * 2004-05-10 2009-12-22 Piling Anti-Lift Systems Device for preventing dock piling or structure piling uplift
US20070075071A1 (en) * 2005-09-30 2007-04-05 Cardenas Carlos A Pipe heater
US7220947B2 (en) 2005-09-30 2007-05-22 Global Heating Solutions, Inc. Pipe heater
US20090283515A1 (en) * 2008-05-16 2009-11-19 Umesh Sopory Heating cable with a heating element positioned in the middle of bus wires
US8212191B2 (en) 2008-05-16 2012-07-03 Thermon Manufacturing Co. Heating cable with a heating element positioned in the middle of bus wires
US7989740B2 (en) 2008-05-16 2011-08-02 Thermon Manufacturing Company Heating cable
US8338759B2 (en) 2008-05-16 2012-12-25 Thermon Manufacturing Company Heating cable
US20110074380A1 (en) * 2008-05-28 2011-03-31 Silveray Co., Ltd. Electric conduction pad and manufacturing method thereof
CN102271430A (en) * 2010-06-03 2011-12-07 无锡恒业电热电器有限公司 High-temperature constant-power parallel-type electric heating strip
US20130140018A1 (en) * 2011-12-01 2013-06-06 Pablo Javier INVIERNO Heater cable for tubing in shale type hydrocarbon production wells exposed to high pressures and wells with annular space flooded eventually or permanently or a combination of both
US9103181B2 (en) * 2011-12-01 2015-08-11 Pablo Javier INVIERNO Heater cable for tubing in shale type hydrocarbon production wells exposed to high pressures and wells with annular space flooded eventually or permanently or a combination of both
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
US10098185B2 (en) * 2013-04-23 2018-10-09 Kima Heating Cable Ab Power controlled heating system
WO2014173737A1 (en) * 2013-04-23 2014-10-30 Kima Heating Cable Ab Power controlled heating system
US20160081140A1 (en) * 2013-04-23 2016-03-17 Kima Heating Cable Ab Power controlled heating system
CN107197554A (en) * 2017-05-31 2017-09-22 泰州瑞侃电热电器有限公司 Carbon fiber parallel electric heat tracing band
WO2019166786A1 (en) * 2018-02-28 2019-09-06 Heat Trace Limited Electrical heating cable
CN112056004A (en) * 2018-02-28 2020-12-08 电伴热有限公司 Electric heating cable
RU2770688C2 (en) * 2018-02-28 2022-04-21 Хит Трейс Лимитед Electric heating cable
US11337278B2 (en) 2018-02-28 2022-05-17 Heat Trace Limited Electrical heating cable
GB2571531B (en) * 2018-02-28 2022-06-08 Heat Trace Ltd Electrical heating cable
CN112056004B (en) * 2018-02-28 2022-11-04 电伴热有限公司 Electric heating cable

Also Published As

Publication number Publication date
JPS4972729A (en) 1974-07-13
JPS5230728B2 (en) 1977-08-10

Similar Documents

Publication Publication Date Title
US3757086A (en) Electrical heating cable
US4117312A (en) Self-limiting temperature electrical heating cable
ATE30825T1 (en) EXTENDED ELECTRIC HEATING ELEMENTS.
EP3043358B1 (en) Metal sheathed cable with jacketed, cabled conductor subassembly
GB1168162A (en) Flexible Electrically Heated Personal Warming Device
ATE268099T1 (en) HEATING LINE
CA2527244C (en) Heating cable
US4308448A (en) Heating cable with a specific heating capacity
US3794752A (en) High voltage cable system free from metallic shielding
KR940006521B1 (en) Electric heater
US3045102A (en) Cold terminal resistance wire
EP3043357B1 (en) Metal sheathed cable with jacketed, cabled conductor subassembly
GB2110910A (en) Electrical strip heater element
GB2236236A (en) Electric heating cable
GB744435A (en) Improvements in or relating to corrugated metal pipes
EP0125747A2 (en) Heat-resistant electrical conducting wire
CN203895139U (en) Resumable temperature-sensitive composite cable
GB928712A (en) Electric cable comprising an external metal sheath
GB891423A (en) Improvements in or relating to electric heating systems utilising coaxial cables
IT8421457A0 (en) INSULATING LAYER WITH IMPROVED CHARACTERISTICS FOR USE AS A DIELECTRIC FOR METALLIC ELECTRIC CONDUCTORS AND THE INSULATED ELECTRICAL CONDUCTOR SO OBTAINED.
JPS6351073A (en) Self-control type heater wire
CN103956201A (en) Recoverable temperature sensing composite cable
IT1197693B (en) Thermal energy transportation closed systems
IT1197606B (en) Haemorrhoids and inflammation treatment compsn.
IT1197709B (en) Active xanthinic derivs.