Electrically heated form-fitting fabric assembly

• US 5,008,517 A
• Filed: 09/08/1989
• Issued: 04/16/1991
• Est. Priority Date: 09/08/1989
• Status: Expired due to Fees

• Current Assignee: Environwear Incorporated
• Original Assignee: Environwear Incorporated
• Inventors: Batcheller, Barry D., Brekkestran, Kevin L.
• Primary Examiner(s): Walberg, Teresa J.
• Application Number:
  US07/404,827
• Time in Patent Office: 585 Days
• Field of Search: 219/211, 219/528, 219/529, 219/549, 219/212
• US Class Current: 219/211
• CPC Class Codes: H05B 2203/003 using serpentine layout
• CPC Class Codes: H05B 2203/014 Heaters using resistive wires or cables not provided for in H05B3/54
• CPC Class Codes: H05B 2203/017 Manufacturing methods or apparatus for heaters
• CPC Class Codes: H05B 2203/036 Heaters specially adapted for garment heating
• CPC Class Codes: H05B 3/342 heaters used in textiles

Abstract

An electrically heated fabric assembly for use with an electrically heated garment. The fabric assembly includes a lightweight, stretchable, form-fitting fabric made from polyphthalate and spandex fibers for covering various portions of the body of a wearer of the garment; and a plurality of flexible, electrical, heat generating wires arranged in a serpentine pattern on various portions of the fabric, and operable to generate heat in response to an electrical current flow through the heating wires. The heating wires are secured to the fabric by cover stitching, accomplished by sewing, to allow the fabric to retain its flexibility. The heating wires each include several conductor elements wound together in a spiral fashion, and each conductor element includes a core portion having wound therearound in a spiral fashion two tinsel-like copper conductors. The core portions each consist of several aromatic polyamide fibers of extremely high tensile strength. A plurality of winged connector assemblies operable to be sewably attached to the fabric are also included for removably connecting the heating wires to an external power source.

Claims

1. An electrically heated form-fitting fabric assembly for use in an electrically heated, cold-weather garment, comprising:

lightweight, stretchable, form-fitting fabric means for covering at least a portion of the body of a wearer of the garment, the fabric means being made at least primarily of a lightweight fabric having (1) a weight in the range of about 2 to 20 ounces per square yard, (2) a break elongation of at least 100 percent, (3) a tensile recovery of at least 50 percent from about a 50 percent elongation, and (4) a tensile strength of at least about 0.2 grams per denier;

flexible conductor means arranged in a serpentine fashion relative to the fabric means, for generating heat in response to an electrical current passed therethrough, thereby providing warmth to the wearer of the garment, including at least one multiple-strand conductor having an insulation jacket;

means for securing the said conductor means to the fabric means, the means for securing including stretchable stitching for securing the conductor and its insulating jacket to the fabric, the stitching further being of a pattern operable to draw portions of the fabric on opposing sides of the conductor upwardly into contact with the insulating jacket so as to partially but not completely circumscribe the conductor and its insulating jacket, said stitching circumscribing that part of the conductor which is not circumscribed by the fabric; and

connector means for removably connecting the conductor means with a power source to thereby provide power to the conductor means, thereby enabling the conductor means to generate heat to heat the garment.

2. The fabric assembly of claim 1, wherein the fabric comprises a flexible, lightweight, stretchable, form-fitting fabric material having a blend of spandex fibers in continuous monofilament form.

3. The fabric assembly of claim 1, wherein the insulating jacket has a fluoropolymer resin operable to conduct heat therethrough in response to the application of heat thereto;

wherein the insulating jacket is approximately 0.010 to 0.025 inches thick; and

wherein the conductor has at least ten individual conductive strands.

4. The fabric assembly of claim 1, wherein the multiple-strand conductor has an ampacity of at least about 7.5 amps of continuous current at about 25°

C. without incurring any damage from the continuous current flow; and

wherein the conductor means is operable and flexible from an operating range of about -40°

C. to 150°

C.

5. The fabric assembly of claim 1, wherein the conductor means has a core comprising intermixed polyester and spandex fibers to increase the tensile breaking strength of the conductor means to about 20 to 30 lbs.

6. The fabric assembly of claim 1, wherein the conductor means comprises a plurality of independent conductors, each such conductor being associated with a particular heating zone.

7. The fabric assembly of claim 1, wherein the fabric means comprises a blend of polyphthalate and spandex fibers to facilitate flexion of the fabric means and to keep the fabric means light in weight, and to provide improved wicking and absorption of moisture.

8. The fabric assembly of claim 1, wherein the conductor means comprises a plurality of independent electrical conductors, each such conductor having an electrical resistance of about 0.039 ohm/ft to about 0.045 ohm/ft at 25°

C.

9. The fabric assembly of claim 1, wherein the conductor means has an outer diameter no greater than about 0.050 inches.

10. For an electrically heated, cold-weather garment having a plurality of discrete heating zones, an electrically heated form-fitting fabric assembly comprising:

a lightweight, stretchable, form-fitting fabric means for tightly covering at least a portion of the body of a wearer of the fabric such that pumping of air is substantially eliminated;

at least one independent, current carrying conductor, the conductor having an electrical resistance of about 0.25 ohm/ft to 0.50 ohm/ft and operable to generate heat in response to a current flow therethrough;

the conductor further being arranged in a serpentine pattern;

a relatively chemically inert insulating jacket for enclosing the conductor, the insulating jacket being of a fluoropolymer resin operable to transfer therethrough heat generated by the conductor to the fabric;

stitching for securing the conductor and the insulating jacket to the fabric, the stitching further being of a pattern operable to draw portions of the fabric on opposing sides of the conductor upwardly into contact with the insulating jacket so as to partially but not completely circumscribe the conductor and its insulating jacket, said stitching circumscribing that part of the conductor which is not circumscribed by the fabric; and

at least one electrical connector means for removably connecting each conductor with an external power source, thereby enabling each conductor to receive a current flow therethrough and to generate heat.

11. For use in an electrically heated, cold-weather garment, an electrically heated form-fitting fabric assembly comprising:

lightweight, stretchable, form-fitting fabric for covering at least a portion of the body of a wearer of the garment;

at least one flexible conductor, arranged in a serpentine fashion relative to the fabric, for generating heat in response to an electrical current passed therethrough; and

stretchable, stitch means for holding the fabric at least partially but not completely around the circumference of the conductor in a manner which allows the conductor to move slightly relative to the fabric wrapped therearound during physical movements associated with use of the garment including the fabric assembly by a wearer thereof the stitch means including stitching being arranged to substantially cover the portion of the conductor not wrapped therearound by the fabric, the fabric and stitching thereby providing a tunnel-like enclosure for holding the conductor tightly against the fabric of the fabric assembly.

12. The fabric assembly of claim 11, wherein the one conductor comprises copper in tinsel form to thereby facilitate flexion of the conductor means without breakage.

13. The fabric assembly of claim 11, wherein the fabric comprises a blend of polyphthalate and spandex fibers to facilitate flexion of the fabric and to keep the fabric light in weight.

14. The fabric assembly of claim 11, wherein the fabric has a weight of about two to fifteen ounces per square yard.

15. The fabric assembly of claim 11, wherein the fabric has a weight between about six to eight ounces per square yard.

16. The fabric assembly of claim 11, wherein the fabric comprises spandex fibers which help allow the fabric to stretch in accordance with physical movements of the wearer of the fabric assembly.

17. The fabric assembly of claim 11, wherein the fabric is operable to provide a wicking action to help absorb moisture and perspiration from the skin of a wearer of the garment and to dissipate such moisture and perspiration rapidly through evaporation, thereby helping to keep the wearer in a comfortable, dry state.

18. The fabric assembly of claim 11, wherein the fabric is made of synthetic material which resists mildew and resists retaining odor, and wherein the fabric assembly is machine washable and dryable.

19. The fabric assembly of claim 11, comprising multiple conductors, with each conductor being arranged in a serpentine pattern such that portions of the conductors near each other are separated by at least one-eighth of an inch.

20. The fabric assembly of claim 19, wherein the portions of the conductors near each other are separated by at least one-half inch.

21. The fabric assembly of claim 11, comprising multiple conductors, with each conductor being arranged in a serpentine pattern which has a plurality of curved portions, and in which the radius of each such curved portion is at least one-half inch.

22. For an electrically heated, cold-weather garment having at least one independent, heat producing conductor, an electrically heated form-fitting fabric assembly comprising:

at least one heat-producing highly flexible insulated electrical conductor;

lightweight, stretchable, form-fitting fabric means for covering at least a portion of the body of a wearer of the garment, the fabric means including at least one layer of thin highly-stretchable synthetic fabric; and

stretchable cover-stitch means for securing the heat producing conductor to the fabric by drawing the fabric partially but not completely around the conductor so as to produce an elongated trough of fabric in which the conductor resides which trough is covered by the cover-stitch means and which allows the heat producing conductor to move slightly relative to the fabric forming the trough during wearing of a garment which includes the fabric assembly.

23. The electrically heated, for-fitting fabric assembly of claim 22, further comprising:

connector means, having at least one wing having a substantially planar surface, for removably connecting the conductor with a power source to thereby allow electrical power to be provided to the conductor, the wing being adapted to readily and securely affix the connector means to the fabric means.

24. The electrically heated form-fitting fabric assembly of claim 22:

wherein the conductor is arranged on the fabric in a serpentine pattern to evenly and uniformly distribute heat produced by the conductor to a portion of the body of a wearer of the garment which is adjacent to the fabric assembly.