Electric heating/warming fabric articles

Information

  • Patent Grant
  • 6215111
  • Patent Number
    6,215,111
  • Date Filed
    Tuesday, December 21, 1999
    24 years ago
  • Date Issued
    Tuesday, April 10, 2001
    23 years ago
Abstract
A fabric article that generates heat upon application of electrical power is formed, for example, by knitting or weaving, to form a fabric prebody. An electrical resistance heating element in the form of a conductive yarn is incorporated into the fabric prebody, the electrical resistance heating elements extending between opposite edge regions of the fabric. Conductive elements are provided for connecting the electrical resistance heating elements to a source of electrical power.
Description




BACKGROUND OF THE INVENTION




Fabric heating/warming articles are known, e.g., in the form of electric blankets, heating and warming pads and mats, heated garments, and the like. Typically, these heating/warming articles consist of a fabric body defining one or a series of envelopes or tubular passageways into which electrical resistance heating wires or elements have been inserted. In some instances, the electric resistance heating wires are integrally incorporated into the fabric body during its formation, e.g. by weaving or knitting. Relatively flexible electric resistance heating wires or elements, e.g. in the form of a core of insulating material, e.g. yarn, about which is disposed an electrical conductive element, e.g. a helically wrapped metal wire or an extruded sheath of one or more layers of conductive plastic, have been incorporated directly into the woven or knitted structure of a fabric body.




SUMMARY OF THE INVENTION




According to one aspect of the invention, a method of forming a fabric article adapted to generate heat upon application of electrical power comprises the steps of: joining, in a continuous web, by a reverse plaiting circular knitting process, a stitch yarn and a loop yarn to form a fabric prebody, the stitch yarn forming a technical face of the fabric prebody and the loop yarn forming a technical back of the fabric prebody, the loop yarn forming in loops that overlay the stitch yarn at the technical face and the technical back of the fabric prebody, at spaced-apart intervals, incorporating into the fabric prebody as the stitch yarn an electrical resistance heating element, forming the fabric prebody into a fabric body, with the electrical resistance heating elements extending between opposite edge regions of the fabric body, and providing conductive elements for connecting the electrical resistance heating elements to a source of electrical power.




Preferred embodiments of the invention may include one or more the following additional steps: finishing at least one of the technical face and the technical back of the fabric body, in a manner avoiding damage to electrical conductivity of the electrical resistance heating elements, to form a fleece surface region, or finishing the technical face of the fabric body, in a manner to avoid damage to electrical conductivity of the electrical resistance heating elements, to form a first fleece surface region, and finishing the technical back of the fabric body in a manner to avoid damage to electrical conductivity of the electrical resistance heating elements to form a second fleece surface region; applying, directly to the continuous web, the conductive elements for connecting the electrical resistance heating elements to a source of electrical power; incorporating into the fabric body the electrical resistance heating element in the form of a conductive yarn comprising a core of insulating material and an electrical resistance heating filament disposed generally about the core, preferably, the conductive yarn further comprises a sheath material generally surrounding the electrical resistance heating filament and the core, preferably the sheath material is formed by wrapping the electrical resistance heating filament and the core with yarn; incorporating into the fabric prebody the electrical resistance heating element in the form of a conductive yarn comprising an electrical resistance heating filament; connecting the conductive element to a source of electric power and generating heat, the source of electric power comprising alternating current or direct current, e.g. in the form of a battery, which may be mounted to the fabric article; limiting formation of loops to a central region of the fabric prebody, the central region being spaced from edge regions in the fabric body, and providing the conductive elements for connecting the electrical resistance heating elements to a source of electrical power in the edge regions of the fabric body; and/or rendering the yarns of the fabric body hydrophilic or hydrophobic.




According to another aspect of the invention, a fabric article adapted to generate heat upon application of electrical power comprises a fabric body, a plurality of spaced apart electrical resistance heating elements incorporated into the fabric body and extending generally between opposite edge regions of the fabric body, and electrical conductor elements extending generally along the opposite edge regions of the fabric body and adapted to connect the plurality of spaced apart electrical resistance heating elements to a source of electrical power.




Preferred embodiments of this aspect of the invention may include one or more the following additional features. The electrical conductor elements are adapted for connecting the plurality of spaced-apart electrical resistance heating elements to a power source of alternating current or to a power source of direct current, e.g., a battery, which may be mounted to the fabric body. A series of at least three of the plurality of electrical resistance heating elements are symmetrically spaced and/or a series of at least three of the plurality of electrical resistance heating elements are asymmetrically spaced. The fabric body comprises a knitted body, e.g. a reverse plaited circular knitted, or other circular knitted (such as double knitted, single jersey knitted, two-end fleece knitted, three-end fleece knitted, terry knitted or double loop knitted), warp knitted or weft knitted body, or a woven body. The fabric body comprises hydrophilic or hydrophobic material. The fabric body has a technical face formed by a stitch yarn and a technical back formed by a loop yarn. The loop yarn forms loops that overlay the stitch yarn at the technical face and the technical back of the fabric prebody. The fabric prebody has loops formed only in a center region. The fabric body has fleece formed upon at least one, and preferably both, of the technical back and the technical face. The conductive yarn is a stitch yarn. The electrical conductor elements, at least in part, are applied as an electrically conductive paste or as an electrically conductive hot melt adhesive. The electrical conductor elements may comprise a conductive wire. The conductive yarn may preferably comprise a core of insulating material, an electrical resistance heating filament disposed generally about the core, and a sheath material generally surrounding the electrical resistance heating filament and the core. Preferably, the core comprises a yarn of synthetic material, e.g. polyester; the sheath material comprises yarn, e.g. of a synthetic material, such as polyester, wrapped about the electrical resistance heating filament and the core; and the electrical resistance heating filament comprises at least one metal filament, and preferably at least three metal filaments, wrapped helically about the core, the metal filament of the electrical resistance heating filament being formed of stainless steel. The electrical resistance heating element has electrical resistance in the range of about 0.1 ohm/cm to about 500 ohm/cm. In other embodiments of the conductive yarn, the core and/or the sheath material may be omitted. The fabric body comprises first and second fabric layers, and the plurality of spaced apart electrical resistance heating/warming elements incorporated into the fabric body are disposed generally between the first and second fabric layers. The fabric body comprises a double knit fabric body and the first and second fabric layers are joined, in face-to-face relationship, by interconnecting yarns, the plurality of spaced apart electrical resistance heating/warming elements incorporated into the fabric body being positioned and spaced apart by the interconnecting yarns and joined by the conductors in a parallel circuit. The first and second fabric layers are formed separately and joined, e.g by laminating or stitching, in face-to-face relationship, with the plurality of spaced apart electrical resistance heating/warming elements incorporated into the fabric body disposed therebetween. The plurality of spaced apart electrical resistance heating/warming elements may be mounted upon a substrate, e.g. an open grid or a moisture resistant, vapor permeable barrier material, the substrate with the plurality of spaced apart electrical resistance heating/warming elements mounted thereupon being disposed between the first and second fabric layers. The plurality of spaced apart electrical resistance heating/warming elements may be mounted upon at least one opposed surface of the first and second fabric layers.




An objective of the invention is to provide electric heating/warming fabric articles, e.g. electric blankets, heating and warming pads, heated garments, etc., into which a plurality of spaced-apart electric resistance heating members, in the form of conductive yarns, are incorporated by a knitting or weaving process. The fabric body of the heating/warming article, including the incorporated electric resistance heating members, may subsequently be subjected to a fabric finishing process, e.g., one or both surfaces of the fabric body may be napped, brushed, sanded, etc., to form fleece. In a planar structure, such as an electric heating blanket, the electric resistance heating members are connected at their ends along opposite edge regions of the planar fabric body, i.e., of the blanket, and may be powered by alternating current or direct current, including by one or more batteries mounted to the blanket.




Other features and advantages will be apparent from the following description of a presently preferred embodiment.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of an electric heating/warming composite fabric article of the invention in the form of an electric blanket;





FIG. 2

is an end section view of the electric heating/warming composite fabric article of

FIG. 1

, taken at the line


2





2


; and





FIG. 3

is a side section view of the electric heating/warming composite fabric article of

FIG. 1

, taken at the line


3





3


.





FIG. 4

is a perspective view of a segment of a circular knitting machine, and





FIGS. 5-11

are sequential views of a cylinder latch needle in a reverse plaiting circular knitting process, e.g. for use in forming an electric heating/warming composite fabric article of the invention.





FIG. 12

is a somewhat diagrammatic end section view of a preferred embodiment of a conductive yarn for an electric heating/warming fabric article of the invention, while





FIGS. 13-16

and


16


A are similar views of alternative embodiments of conductive yarns for electric heating/warming fabric articles of the invention.





FIG. 17

is a somewhat diagrammatic section view of a segment of a tubular knit fabric during knitting, and





FIG. 18

is a somewhat diagrammatic perspective view of the tubular knit fabric of FIG.


17


.





FIG. 19

is an end section view, similar to

FIG. 2

, of an electric heating/warming fabric article of the invention with fleece on both faces;

FIG. 19A

is similar view of an electric heating/warming fabric article of the invention, e.g., a sheet or the like, without fleece on either face; and





FIG. 20

is an enlarged, plan view of the technical face showing an alternative embodiment of a conductor element.





FIGS. 21

,


22


and


23


are somewhat diagrammatic representations of other embodiments of heating/warming fabric articles of the invention, as adapted to be powered by direct current, e.g., an automobile warming or heating pad (FIG.


21


), adapted to be powered from an automobile battery; and a stadium or camping blanket (

FIG. 22

) and a garment (FIG.


23


), adapted to be powered from a battery replaceably mounted to the article.





FIG. 24

is a somewhat diagrammatic representation of another embodiment of a heating/warming fabric body of the invention, with a double knit fabric body having two, spaced-apart fabric layers joined by interconnecting yarns; and





FIG. 25

is a somewhat diagrammatic representation of yet another embodiment of a heating/warming fabric body of the invention, with two, spaced-apart fabric layers joined about electric heating/warming fabric.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring to

FIG. 1

, an electric heating/warming composite fabric article of the invention, e.g. an electric blanket


10


, adapted to generate heat upon application of electrical power, consists of a fabric body


12


having a technical back


14


and a technical face


16


. The fabric body


12


incorporates a plurality of spaced-apart electric resistance heating elements


18


extending between opposite edge regions


20


,


21


of the fabric body.




Referring also to

FIGS. 4-11

, in a preferred embodiment, the fabric body


12


is formed (in a continuous web) by joining a stitch yarn


22


and a loop yarn


25


in a standard reverse plaiting circular knitting (terry knitting) process, e.g. as described in Knitting Technology, by David J. Spencer (Woodhead Publishing Limited, 2nd edition, 1996), the entire disclosure of which is incorporated herein by reference. Referring again to

FIGS. 2 and 3

, in the terry knitting process, the stitch yarn


22


forms the technical face


16


of the resulting fabric body and the loop yarn


25


forms the opposite technical back


14


, where it is formed into loops (


25


,

FIG. 10

) extending over the stitch yarn


22


. In the fabric body


12


formed by reverse plaiting circular knitting, the loop yarn


25


extends outwardly from the planes of both surfaces and, on the technical face


16


, the loop yarn


25


covers the stitch yarn


22


(e.g., see FIG.


17


). As a result, during napping of the opposite fabric surfaces to form a fleece, the loop yarn


25


protects the stitch yarn


22


, including the conductive yarns


26


knitted into the fabric body in the stitch yarn position.




The loop yarn


25


forming the technical back


14


of the knit fabric body


12


can be made of any synthetic or natural material. The cross section and luster of the fibers or the filament may be varied, e.g., as dictated by requirements of the intended end use. The loop yarn can be a spun yarn made by any available spinning technique, or a filament yarn made by extrusion. The loop yarn denier is typically between 40 denier to 300 denier. A preferred loop yarn is a 200/100 denier T-653 Type flat polyester filament, e.g. as available commercially from E.I. duPont de Nemours and Company, Inc., of Wilmington, Delaware.




The stitch yarn


22


forming the technical face


16


of the knit fabric body


12


can be also made of any type of synthetic or natural material in a spun yarn or a filament yarn. The denier is typically between 50 denier to 150 denier. A preferred yarn is a 70/34 denier filament textured polyester, e.g. as available commercially from UNIFI, Inc., of Greensboro, N.C.




Referring now also to

FIG. 12

, and also to

FIGS. 13-16

, at spaced intervals during the knitting process, an electric resistance heating member


18


in the form of a conductive yarn


26


is incorporated into the fabric body


12


in place of the stitch yarn


22


. Referring to

FIG. 12

, in a preferred embodiment, the conductive yarn


26


forming the electrical resistance heating elements


18


consists of a core


28


of insulating material, e.g. a polyester yarn, about which extends an electrical conductive element


30


, e.g. three filaments


31


of stainless steel wire (e.g.


316


L stainless steel) wrapped helically about the core


28


, and an outer covering


32


of insulating material, e.g. polyester yarns


33


(only a few of which are suggested in the drawings) helically wrapped about the core


28


and the filaments


31


of the electrical conductive element


30


. The conductive yarn


26


is available, e.g., from Bekaert Fibre Technologies, Bekaert Corporation, of Marietta, Ga., as yarn series VN14.




The number of conductive filaments in the conductive yarn, and where the filaments are located, are dependent, e.g., on the end use requirements. For example, in alternative configurations, in

FIG. 13

, conductive yarn


26


′ has four filaments


31


′ wrapped about core


28


′ with an outer covering


32


′ of polyester yarns


33


′; in

FIG. 14

, conductive yarn


26


″ has three filaments


31


″ wrapped by outer covering


32


″ of polyester yarns


33


″, without a core. Referring to

FIGS. 15 and 16

, in other embodiments, conductive yarns


37


,


37


′, respectively, are formed without an outer covering about the filaments


35


,


35


′, respectively, wrapped about core


34


,


34


′, respectively, the stitch yarn


22


and loop yarn


25


of the fabric body


12


instead serving to insulate the conductive yarns in the heating/warming fabric article. Referring to

FIG. 16A

, a conductive yarn


37


″ without an outer cover or sheath, formed, e.g., of one or more bare filaments (one filament


35


″ is shown) may also be formed without an insulating core, again, with yarn of the fabric body arranged to insulate the conductive yarns in the heating/warming fabric body. The resistance of the conductive yarn can be selected in the range, e.g., of from about 0.1 ohm/cm to about 500 ohm/cm on the basis of end use requirements of the heating/warming fabric article


10


. However, conductive yarns performing outside this range can also be employed, where required. The core of the conductive yarn and the sheath material of the outer covering over the conductive filaments may be made of synthetic or natural material. The outer covering may also have the form of a sleeve, e.g. a dip-coated or extruded sleeve. Conductive yarns of different constructions suitable for use according to this invention can also be obtained from Bekaert Fibre Technologies.




In the preferred method of the invention, the fabric body


12


is formed by reverse plaiting on a circular knitting machine. This is principally a terry knit, where the loops formed by the loop yarn


25


cover the stitch yarn


22


on the technical face


16


(see FIG.


17


).




The conductive yarn is incorporated into the knit fabric prebody formed on the circular knitting machine at a specific spacing or distance apart, D (FIG.


1


), for uniform heating in the resulting heating/warming fabric article


10


. In a fabric prebody of the invention, the spacing is typically a function, e.g., of the requirements of heating, energy consumption and heat distribution in the article to be formed. For example, the spacing of conductive yarns may be in the range of from about 0.02 inch to about 2.5 inches. However, other spacing may be employed, depending on the conditions of intended or expected use, including the resistance of the conductive yarns. The conductive yarns may be spaced symmetrically from each other, or the conductive yarns may be spaced asymmetrically, with varying spacing, as desired. Also, in a fabric body of the invention, the power consumption for each conductive yarn is generally considerably lower than in the separate heating wires of prior art devices. As a result, the conductive yarns in a fabric body of the invention can be more closely spaced, with less susceptibility to hot spots.




The preferred position of the conductive yarn is in the stitch position of the circular knitted construction. The conductive yarn may then be knit symmetrically, i.e., at a specific distance apart, in each repeat, i.e., the conductive yarn can be in stitch position at any feed repeat of the circular knitting machine. Alternatively, the conductive yarns may be knit asymmetrically, with the yarns more closely or widely spaced, e.g., as desired or as appropriate to the intended product use. Again, the specific number of feeds, and the spacing of the conductive yarns, is dependent on the end use requirements.




Referring to

FIGS. 17 and 18

, the end regions


20


,


21


may be formed as a panel


90


in the tubular knit body


92


. The edge regions


20


,


21


of the fabric body are preferably formed without loops, and in a manner such that the edge regions do not curl upon themselves, e.g. the edge region panel is formed by single lacoste or double lacoste knitting. The ends portions


36


(

FIG. 1

) of the conductive yarns


26


extending into the flat regions


20


,


21


without loops are thus more easily accessible in the end regions for completing an electrical heating circuit, as described below.




The tubular knit body


92


is removed from the knitting machine and slit, e.g. along a line of stitches


94


marking the desired slit line, to create a planar fabric. Alternatively, for increased accuracy, the tubular knit body


92


may be slit on line, e.g. by a cutting edge mounted to the knitting machine.




As described above, in the fabric article


10


of the invention, spaced apart conductive yarns


18


are electrically interconnected in parallel by conductor elements


40


, e.g., in a blanket, extending along the edge regions. However, during the knitting process of formation, a continuous length of conductive yarn


26


′ (

FIG. 18

) may be inserted continuously during knitting, with the continuous length of conductive yarn only thereafter being segmented, e.g. by slitting the tubular knit body


92


(FIG.


18


), into separate, spaced apart conductive yarns


26


to form the fabric article of the invention.




Preferably, the knitted fabric body


12


incorporating the electric resistance heating elements


18


in the form of the conductive yarns is next subjected to finishing. During the finishing process, the fabric body


12


may go through processes of sanding, brushing, napping, etc., to generate a fleece


38


. The fleece


38


may be formed on one face of the fabric body


10


(FIG.


2


), e.g., on the technical back


14


, in the loop yarn, or a fleece


38


,


38


′ may be formed on both faces of the fabric body


10


′ (FIG.


19


), including on the technical face


16


, in the overlaying loops of the loop yarn and/or in the stitch yarn. In either case, the process of generating the fleece on the face or faces of fabric body is preferably performed in a manner to avoid damage to the conductive yarn which is part of the construction of the fabric body


12


. Alternatively, referring to

FIG. 19A

, e.g. for the purpose of providing a fabric article in the form of a sheet


98


or the like, rather than in the form of a blanket, neither of surfaces


93


,


95


may be subjected to finishing.




The fabric body may also be treated, e.g. chemically, to render the material hydrophobic or hydrophilic.




After finishing, and after the fabric body is heat set for width, the electric resistance heating elements are connected to a source of electrical power by conductors


40


in opposite edge regions


20


,


21


(where, preferably, there are no loops on the surface), thereby to complete the electrical circuit. (The conductors or busses


40


may be formed on the technical back


14


, as shown in

FIG. 1

, or they may instead be formed on the technical face


16


, as seen in

FIGS. 19 and 20

.) Any suitable methods may be used to complete the circuit. For example, referring to

FIG. 1

, the conductor


40


may, at least in part, be applied in the form of a conductive paste, e.g. such as available commercially from Loctite Corporation, of Rocky Hill, Conn., or in the form of a conductive hot melt adhesive, conductive tape (with fabric or plastic base/carrier, or the like. The conductive paste or adhesive may be applied as a stripe to a surface of the fabric body


10


in electrical conductive relationship with the electrical resistance heating elements


18


, and then connected to the power source. (If necessary, the conductive yarns may be exposed, e.g., the polyester covering yarn may be removed with solvent or localized heat, e.g. by laser; the covering yarn may be manually unraveled; or the fabric body


10


may be formed with a needle out in the flat regions


20


,


21


, thus to facilitate accessibility to each of the conductive yarns.) Alternatively, referring to

FIG. 20

, the conductor


40


′ may consist of localized dots or regions


42


of conductive paste applied in electrical contact with exposed portions of the electric resistance heating elements


18


, with a conductive metal wire


44


disposed in electrical conductive contact with, and extending, preferably continuously, between, the localized conductive paste regions


42


. The electric conductor


40


′ is thereafter covered by a cloth trim or edging material


46


, attached, e.g., by stitching along the edge of the fabric body


10


′.




The completed circuit is next connected to a power source to supply electrical power to the electrical resistance heating elements for the required amount of heat generation. For example, referring to

FIG. 1

, an electric heating/warming fabric article


10


of the invention (an electric blanket) is adapted for connection to a source of alternating current by means of plug


50


on cord


51


for insertion in household outlet


52


. Referring to

FIG. 21

, a warming or heating pad


60


of the invention, e.g. for an automobile seat, is adapted for connection to a source of direct current by means of plug


62


on cord


64


for insertion into the cigarette lighter or other power outlet


66


of an automobile. Referring to

FIGS. 22 and 23

, a stadium or camping blanket


70


and a garment


80


of the invention each includes a source of direct current, i.e. a battery pack


72


,


82


, respectively, e.g., as available from Polaroid Corporation, of Cambridge, Mass., replaceably mounted to the heating/warming fabric article, e.g. in a pocket


74


,


84


, respectively. Referring to

FIG. 22

, the pocket may be secured by a hook-and-loop type fastener


76


. Preferably, for certification by Underwriters' Laboratory (UL®), the voltage supplied by the power source to the electrical resistance heating elements is lower than 25 volts, e.g. a Class II UL® certified transformer may be used to step down a 110 v power supply to 25 volts or under.




Other embodiments are within the invention. For example, any type of yarn may be employed.




Also, other methods of constructing fabric heating/warming articles of the invention may be employed, e.g. the yarn may be incorporated by warp knit or weft knit construction or by woven construction. Alternatively, referring to

FIG. 24

, the fabric body may be formed as a double knit fabric body


100


, with two, separate fabric layers


102


,


104


joined by interconnecting yarns


106


, In this embodiment, conductive yarns


108


are disposed between the separate fabric layers


102


,


104


, e.g. by insertion during the knitting process or thereafter, and maintained apart and in position by the interconnecting yarns


106


.




Referring to

FIG. 25

, in another embodiment of a fabric article


120


of the invention, separate fabric layers


122


,


124


disposed at opposite surfaces of the fabric article


120


may be formed separately and joined together, in face-to-face engagement, in a separate operation, e.g. by laminating or stitching. In this embodiment, the heating/warming circuit


126


may be formed upon a separate substrate


128


, e.g. upon an open mesh or grid, e.g. scrim, or upon a material forming a barrier that is waterproof yet vapor permeable, e.g., as described in U.S. application No. 09/298,722, filed Apr. 23, 1999, the complete disclosure of which is incorporated herein by reference, and positioned between the separate fabric layers, e.g. during the lamination process. Alternatively, the circuit may be formed upon one or both of the opposed surfaces of the separate layers, e.g as described in U.S. application No. 09/298,722, mentioned above, or as described in U.S. application No. 09/296,375, filed Apr. 22, 1999, the complete disclosure of which is incorporated herein by reference, before the layers are joined.




Also, for improved efficiency during manufacturing, busses or conductors


40


may be applied to the fabric body


12


before it is subjected to finishing. For example, the conductor


40


applied as a continuous strip of conductive paste or adhesive may be applied directly to the continuous web, either continuously, or in a predetermined intermittent pattern, e.g. using a print wheel or the like. The fabric body


12


, with the conductors


40


formed thereupon, may thereafter be subjected to finishing and other steps of manufacturing.



Claims
  • 1. A fabric article adapted to generate heat upon application of electrical power, comprising:a fabric body knitted or woven of non-conductive yarns, a plurality of spaced apart electrical resistance heating elements in the form of conductive yarns knitted or woven into said fabric body together with the non-conductive yarns and extending generally between opposite edge regions of said fabric body, and electrical conductor elements extending generally along said opposite edge regions of said fabric body and adapted to connect said plurality of spaced apart electrical resistance heating elements in a parallel electrical circuit to a source of electrical power, said fabric body having a technical face and a technical back, with fleece on at least one of said technical face and said technical back formed by finishing non-conductive yarns of said at least one of said technical face and said technical back in manner to avoid damage to electrical conductivity performance of the conductive yarns knitted or woven together with the non-conductive yarns in said fabric body.
  • 2. The fabric article of claim 1, wherein said electrical conductor elements are adapted for connecting said plurality of spaced-apart electrical resistance heating elements in the parallel electrical circuit to a power source of alternating current.
  • 3. The fabric article of claim 1, wherein said electrical conductor elements are adapted for connecting said plurality of spaced-apart electrical resistance heating elements in the parallel electrical circuit to a power source of direct current.
  • 4. The fabric article of claim 3, wherein said power source of direct current comprises a battery.
  • 5. The fabric article of claim 4, wherein said battery is mounted to said fabric body.
  • 6. The fabric article of claim 1, wherein said fabric article further comprises a power source connected to said plurality of spaced apart electrical resistance heating elements by said electrical conductor elements, said power source comprising a battery mounted to said fabric body.
  • 7. The fabric article of claim 1, wherein a series of at least three electrical resistance heating elements of said plurality of electrical resistance heating elements are symmetrically spaced.
  • 8. The fabric article of claim 7, wherein a series of at least three electrical resistance heating elements of said plurality of electrical resistance heating elements are asymmetrically spaced.
  • 9. The fabric article of claim 1, wherein a series of at least three electrical resistance heating elements of said plurality of electrical resistance heating elements are asymmetrically spaced.
  • 10. The fabric article of claim 1, wherein said fabric body comprises a knitted body.
  • 11. The fabric article of claim 10, wherein said fabric body comprises a reverse plaited circular knitted body.
  • 12. The fabric article of claim 10, wherein said fabric body comprises a double knit body consisting of two, separate fabric sheets joined by interconnecting yarns.
  • 13. The fabric article of claim 1, wherein said fabric body comprises a woven body.
  • 14. The fabric article of claim 1, wherein said fabric body comprises hydrophilic material.
  • 15. The fabric article of claim 1, wherein said fabric body comprises hydrophobic material.
  • 16. The fabric article of claim 1, wherein said technical face is formed by a stitch yarn and said technical back is formed by a loop yarn.
  • 17. The fabric article of claim 16, wherein said loop yarn overlays the stitch yarn at the technical face and forms loops at the technical back of the fabric body.
  • 18. The fabric article of claim 16, wherein said fabric body has loops formed only in a center region.
  • 19. The fabric article of claim 16, wherein said fabric body has a fleece formed upon both of said technical back and said technical face.
  • 20. The fabric article of claim 16, wherein said conductive yarn is a stitch yarn.
  • 21. The fabric article of claim 1, wherein said electrical conductor elements, at least in part, are applied as a conductive paste.
  • 22. The fabric article of claim 21, wherein said electrical conductor elements comprise a conductive wire.
  • 23. The fabric article of claim 1, wherein said electrical conductor elements, at least in part, are applied as a conductive hot melt adhesive.
  • 24. The fabric article of claim 1, wherein said conductive yarns comprise a core of insulating material, an electrical resistance heating filament disposed generally about said core, and a sheath material generally surrounding said electrical resistance heating filament and said core.
  • 25. The fabric article of claim 24, wherein said core comprises a yarn of synthetic material.
  • 26. The fabric article of claim 25, wherein said synthetic material is polyester.
  • 27. The fabric article of claim 24, wherein said electrical resistance heating filament comprises at least one metal filament wrapped helically about said core.
  • 28. The fabric article of claim 27, wherein said electrical resistance heating filament comprises at least three metal filaments wrapped helically about said core.
  • 29. The fabric article of claim 27, wherein said at least one metal filament of said electrical resistance heating element is formed of stainless steel.
  • 30. The fabric article of claim 24, wherein said electrical resistance heating element has electrical resistance in the range of about 0.1 ohm/cm to about 500 ohm/cm.
  • 31. The fabric article of claim 24, wherein said sheath material comprises yarn wrapped about said electrical resistance heating filament and said core.
  • 32. The fabric article of claim 31, wherein said sheath material comprises a yarn of synthetic material.
  • 33. The fabric article of claim 32, wherein said synthetic material is polyester.
  • 34. The fabric article of claim 1, wherein said conductive yarns comprise an electrical resistance heating filament and a sheath material generally surrounding said electrical resistance heating filament.
  • 35. The fabric article of claim 34, wherein said electrical resistance heating filament comprises at least one metal filament.
  • 36. The fabric article of claim 35, wherein said electrical resistance heating filament comprises at least three metal filaments.
  • 37. The fabric article of claim 35, wherein said at least one metal filament of said electrical resistance heating element is formed of stainless steel.
  • 38. The fabric article of claim 34, wherein said electrical resistance heating element has electrical resistance in the range of about 0.1 ohm/cm to about 500 ohm/cm.
  • 39. The fabric article of claim 34, wherein said sheath material comprises yarn wrapped about said electrical resistance heating filament.
  • 40. The fabric article of claim 39, wherein said sheath material comprises a yarn of synthetic material.
  • 41. The fabric article of claim 40, wherein said synthetic material is polyester.
  • 42. The fabric article of claim 1, wherein said conductive yarns comprise a core of insulating material and an electrical resistance heating filament disposed generally about said core.
  • 43. The fabric article of claim 42, wherein said core comprises a yarn of synthetic material.
  • 44. The fabric article of claim 43, wherein said synthetic material is polyester.
  • 45. The fabric article of claim 42, wherein said electrical resistance heating filament comprises at least one metal filament.
  • 46. The fabric article of claim 45, wherein said electrical resistance heating filament comprises at least three metal filaments.
  • 47. The fabric article of claim 45, wherein said at least one metal filament of said electrical resistance heating element is formed of stainless steel.
  • 48. The fabric article of claim 42, wherein said electrical resistance heating element has electrical resistance in the range of about 0.1 ohm/cm to about 500 ohm/cm.
  • 49. The fabric article of claim 1, wherein said electrical resistance heating element has the form of a conductive yarn comprising an electrical resistance heating filament.
  • 50. The fabric article of claim 49, wherein said electrical resistance heating filament comprises at least one metal filament.
  • 51. The fabric article of claim 50, wherein said at least one metal filament of said electrical resistance heating element is formed of stainless steel.
  • 52. The fabric article of claim 49, wherein said electrical resistance heating filament comprises at least three metal filaments.
  • 53. The fabric article of claim 49, wherein said electrical resistance heating element has electrical resistance in the range of about 0.1 ohm/cm to about 500 ohm/cm.
  • 54. A fabric article adapted to generate heat upon application of electrical power, formed by a method comprising the steps of:joining, by a reverse plaiting circular knitting process, a non-conductive stitch yarn and a non-conductive loop yarn to form a fabric prebody, the loop yarn overlaying the stitch yarn at a technical face and forming in loops at a technical back of the fabric prebody, at spaced-apart intervals, incorporating into the fabric prebody as the stitch yarn an electrical resistance heating/warming element in the form of a conductive yarn, forming the fabric prebody into a fabric body, with the electrical resistance heating/warming elements extending between opposite edge regions of the fabric body, in a manner to avoid damage to electrical conductivity performance of the electrical resistance heating/warming elements, finishing non-conductive yarns of at least one of said technical face and said technical back of the fabric body to form a fleece surface region, and providing conductive elements for connecting the electrical resistance heating/warming elements, in parallel, to a source of electrical power.
  • 55. The fabric article of claim 54, formed by method further comprising the steps of:finishing non-conductive yarns of the technical face of the fabric body, in a manner to avoid damage to electrical conductivity performance of the electrical resistance heating/warming elements, to form a first fleece surface region, and finishing non-conductive yarns of the technical back of the fabric body in a manner to avoid damage to electrical conductivity performance of the electrical resistance heating/warming elements to form a second fleece surface region.
Parent Case Info

This application is a continuation-part of U.S. application Ser. No. 09/296,375, filed Apr. 22, 1999, and now abandoned. The invention relates to fabric articles which generate heat/warmth upon application of electricity.

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Continuation in Parts (1)
Number Date Country
Parent 09/296375 Apr 1999 US
Child 09/468627 US