Patent Grant
6888112
The invention relates to woven, fibrous fabric articles that generate heat/warmth upon application of electricity.
Fabric or fibrous 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 body defining one or a series of envelopes or tubular passageways into which electrical conductance heating wires or elements have been inserted. In some instances, the electric conductance heating wires are integrally incorporated into the body during its formation, e.g. by weaving or knitting. Relatively flexible electric conductance 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 fabricated directly into the woven or knitted structure of a fabric body. For example, in Kishimoto U.S. Pat. No. 5,422,462, conductive yarns are selectively substituted for warp and/or weft yarns during formation of a woven body. The conductive yarns are then connected at their ends to a source of electrical current.
According to one aspect of the invention, a woven fibrous article adapted to generate heat upon application of electrical power comprises a woven fibrous body comprising a set of non-conductive warp yarns and a set of non-conductive filling or weft yarns, one of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in one or more first regions comprising relatively more coarse yarns and in one or more second regions comprising relatively more fine yarns with electrical conductor elements extending generally along the second regions of the woven fibrous body, and the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in the one or more first regions and in the one or more second regions comprising relatively more fine yarns, with a plurality of spaced apart electrical conductance heating elements in the form of conductive elements joined in the woven fibrous body with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns to extend generally between opposite second regions of the woven fibrous body, the conductor elements being adapted to connect the plurality of spaced apart electrical conductance heating elements in a parallel electrical circuit to a source of electrical power.
Preferred embodiments of this aspect of the invention may include one or more of the following additional features. The woven fibrous article has fleece upon at least one surface of the woven fibrous body, formed by finishing fibers of the relatively more coarse yarns in the one or more first regions of the one of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in a manner to avoid damage to electrical conductivity performance of the electrical conductance heating elements joined with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns of the woven fibrous body. The woven fibrous body has fleece formed in the relatively more coarse non-conductive fibers upon one surface or upon both surfaces. In the one or more first regions, the set of non-conducting warp yarns comprises the relatively more coarse yarns and the set of non-conducting filling or weft yarns comprises the relatively more fine yarns. Preferably, the one or more second regions comprises selvedge or edge regions. Alternatively, in one or more first regions, the set of non-conducting filling or weft yarns comprises the relatively more coarse yarns and the set of non-conducting warp yarns comprises the relatively more fine yarns. Preferably, the one or more second regions comprises spaced regions with one or more first regions disposed therebetween. The one or more second regions comprises a plurality of spaced second regions with one or more first regions disposed therebetween. A series of at least three electrical conductance heating elements of the plurality of electrical conductance heating elements are symmetrically spaced. Selected of the electrical conductance heating elements are asymmetrically spaced to provide selected localized regions of heating. Selected of the conductive elements have relatively lower linear resistance than other of the conductive elements, to provide selected localized regions of relatively greater heating. Selected of the conductive elements of relatively lower linear resistance are symmetrically spaced and/or asymmetrically spaced. The conductive elements have the form of a conductive yarn. The fibrous body comprises hydrophilic material and/or hydrophobic material. The electrical conductor elements are adapted for connecting the plurality of spaced-apart electrical conductance heating elements in the parallel electrical circuit to a power source, e.g., of alternating current or of direct current, e.g. a battery mounted to the woven fibrous body. The electrical conductor elements are woven into the second regions of the woven fibrous body, e.g., with the non-conductive warp yarns or with the non-conductive filling or weft yarns. The electrical conductor elements comprise at least two yarns. The electrical conductor elements, at least in part, are applied as a conductive paste. The electrical conductor elements comprise a conductive wire. The electrical conductor elements, at least in part, are applied as a conductive hot melt adhesive. The electrical conductor elements comprise a conductive yarn or a conductive thread. The electrical conductor elements are attached upon a surface in a second region of the woven fibrous body. The electrical conductor elements are attached: by stitching, e.g. embroidery stitching, by sewing, by adhesive, by laminating, by mechanical fastening, and/or by strain relief fastening. The electrical conductance heating element has the form of a conductive yarn comprising a core, an electrical conductance heating filament, a sheath material wrapped about the core, and/or an overwrap comprising insulating material wrapped about the core and the sheath. In one embodiment, the core may comprises the electrical conductance heating element and the sheath comprises insulating material. In another embodiment, the core comprises insulating material and the sheath wrapped about the core comprises the electrical conductance heating element. The electrical conductance heating element may instead have the form of a conductive yarn comprising an electrical conductance heating filament. The electrical conductance heating element has electrical resistivity in the range of about 0.1 ohm/cm to about 500 ohm/cm.
According to one aspect of the invention, a woven fibrous article adapted to generate heat upon application of electrical power is formed by a method comprising the steps of: joining a set of non-conductive warp yarns and a set of non-conductive filling or weft yarns to form a woven fibrous body, one of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in one or more first regions comprising relatively more coarse yarns and in one or more second regions comprising relatively more fine yarns and the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in the one or more first regions and in the one or more second regions comprising relatively more fine yarns, joining, in the woven fibrous body, with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns, the plurality of spaced apart electrical conductance heating elements in the form of conductive elements, to extend generally between opposite second regions of the woven fibrous body, and connecting the plurality of spaced apart electrical conductance heating elements to electrical conductor elements extending generally along the second regions of the woven fibrous body to form a parallel electrical circuit for connection to a source of electrical power.
Preferred embodiments of this aspect of the invention may include the following additional feature. The method further comprises the step of: finishing relatively more coarse yarns fibers in the one or more first regions of the set of the non-conductive warp yarns and the set of non-conductive filling or weft yarns in a manner to avoid damage to electrical conductivity performance of the conductive elements joined with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns of the woven fibrous body.
According to yet another aspect of the invention, a method of forming a woven fibrous article adapted to generate heat upon application of electrical power comprises the steps of: joining a set of non-conductive warp yarns and a set of non-conductive filling or weft yarns to form a woven fibrous body, one of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in one or more first regions comprising relatively more coarse yarns and in one or more second regions comprising relatively more fine yarns and the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns in the one or more first regions and in the one or more second regions comprising relatively more fine yarns, joining, in the woven fibrous body, with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns, the plurality of spaced apart electrical conductance heating elements in the form of conductive elements, to extend generally between opposite second regions of the woven fibrous body, and connecting the plurality of spaced apart electrical conductance heating elements to electrical conductor elements extending generally along the second regions of the woven fibrous body to form a parallel electrical circuit for connection to a source of electrical power.
Preferred embodiments of this aspect of invention may include one or more of the following additional features. The method further comprises the steps of: finishing relatively more coarse yarns fibers in the one or more first regions of the set of the non-conductive warp yarns and the set of non-conductive filling or weft yarns in a manner to avoid damage to electrical conductivity performance of the conductive elements joined with the other of the set of non-conductive warp yarns and the set of non-conductive filling or weft yarns of the woven fibrous body. The method further comprises the step of connecting the conductive element to a source of electric power and generating heat. The method further comprises the step of connecting the conductive element to a source of electric power comprising alternating current and generating heat. The method further comprises the step of connecting the conductive element to a source of electric power comprising direct current, e.g. in the form of a battery, which may be mounted to the woven fibrous article, and generating heat. The method further comprises the step of rendering elements of the woven fibrous body hydrophilic or rendering elements of the woven fibrous body hydrophobic.
Objectives of the invention include to provide woven, fibrous electric heating articles, e.g. electric blankets, heating and warming pads, heated garments, etc., into which a plurality of spaced-apart electric conductance heating members, in the form of conductive elements, are joined with non-conductive yarns or fibers. The woven fibrous body of the heating article is subsequently subjected to a finishing process, e.g., relatively more coarse non-conductive yarns in selected (first) regions at one or both surfaces of the body may be napped, brushed, sanded, etc., in a manner to avoid damage to electrical conductance of the electric conductance heating elements, to form fleece. In a planar structure, such as an electric heating blanket, the electric conductance heating members are connected at their ends, e.g., in selected (second) regions of relatively more fine yarns along opposite selvedge or edge regions, or in spaced regions at opposite edges of first regions, of the planar body, i.e., of the blanket, and may be powered by alternating current or direct current, e.g., by one or more batteries mounted to the body of the woven fibrous heating/warming article.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
Referring to
According to one preferred embodiment of the invention, the woven fibrous body 12 incorporating the electric conductance heating elements 30 can be completed in an unfleeced state, e.g., for use as an electric mattress pad 11, as shown in
Alternatively, according to other preferred embodiments of the invention, the woven fibrous body 12 incorporating the electric conductance heating elements 30 may next be subjected to finishing, e.g., sanding, brushing, napping, etc., to generate a fleece or raised surface. For example, fleece 32 may be formed on one surface of the woven body 12 (FIG. 4A), or fleece 34, 34′ may be formed on both surfaces of the woven body 12′ (FIG. 4B). In either case, the process of generating fleece on the surface or surfaces of woven body is preferably performed in a manner to raise the relatively more coarse yarns 20 in the first region 18, while the relatively finer warp yarns 24 with the conductive bus 26 in the second regions, as well as the relatively finer, tight weft or filling yarns 28 (e.g., high level of twist, high level of tie down), are not raised. The finishing process is also conducted in a manner to avoid damage to the electrical conductance heating yarns 30, like those made with stainless steel filaments, that are part of the construction of the woven body 12 in the weft or filling direction (arrow, F). In particular, fleece 32 (or fleece 34, 34′) is formed in a manner that avoids damage to the conductive filaments of the electrical conductance heating yarns 30 that would result in an increase in resistance to the point of creating an undesirable local hot spot, or would sever electrical conductance heating yarns 30 completely, which could result in undesirable increased electrical flow elsewhere in the circuit. The material of the woven body 12 may also be treated, e.g. chemically, to render the material hydrophobic or hydrophilic.
Referring to
As described above, the woven fibrous body 42 incorporating the electric conductance heating elements 50 may be completed in the form of an electrical blanket 41 in its unfleeced state (FIG. 6). Alternatively, it may next be subjected to finishing, e.g., sanding, brushing, napping, etc., to generate a fleece. Fleece 64 may also be formed on one surface of the woven body 43 (FIG. 6A), or fleece 66, 66′ may be formed on both surfaces of the woven body 43′ (FIG. 6B). In either case, the process of generating the fleece on the surface or surfaces of woven body is preferably performed in a manner to raise the relatively more coarse yarns 52 in the first region 54, while the relatively finer weft or filling yarns 60 with the conductive bus 62 in the second regions, as well as the relatively finer, tight warp yarns 48 (e.g., high level of twist, high level of tie down), are not raised. The finishing process is also conducted in a manner to avoid damage to the electrical conductance heating yarns 50, like those made with stainless steel filaments, that are part of the construction of the woven body 42 in the weft or filling direction (arrow, F). In particular, the fleece 64 (or fleece 66, 66′) is formed in a manner that avoids damage to the conductive filaments of the electrical conductance heating yarns 50.
Referring to now to
Once again, as described above, the woven fibrous body 72 incorporating the electric conductance heating elements 80 may be completed in the form of an electrical heating pad 71 in its unfleeced state (FIG. 8). Alternatively, it may next be subjected to finishing, e.g., sanding, brushing, napping, etc., to generate a fleece. Fleece 92 may also be formed on one surface of the woven body 73 (FIG. 8A), or fleece 94, 94′ may be formed on both surfaces of the woven body 73′ (FIG. 8B). In either case, the process of generating the fleece on the surface or surfaces of woven body is preferably performed in a manner to raise the relatively more coarse weft or filling yarns 84 in the first regions 82, while the relatively finer weft or filling yarns 88 with the conductive bus 90 in each of the second regions 86, as well as the relatively finer, tight warp yarns 78 are not raised. The finishing process is also conducted in a manner to avoid damage to the electrical conductance heating yarns 80, like those made with stainless steel filaments, that are part of the construction of the woven body 72 in the warp direction (arrow, W).
Referring to
The number of conductive filaments in the conductive yarn, and the positioning of the conductive filaments within the conductive yarn, are dependent, e.g., on end use requirements. For example, in alternative configurations, in
The resistivity of the conductive yarn 30 can be selected in the range of, e.g., from about 0.1 ohm/cm to about 500 ohm/cm, on the basis of end use requirements of the woven fibrous article. However, conductive yarns performing outside this range can also be employed, where required or desired. Referring again, by way of example, to
Referring now to
Alternatively, the conductive bus 120 may instead be applied before, or in the absence of, finishing (and/or before heat setting), since the conductive buses 120 are advantageously located in the second edge or selvedge regions 22 of the relatively finer yarns 24, 28 (which are not finished), and not in a first or central region 18 of the relatively more coarse yarns 20. Any suitable method may be used to complete the circuit. For example, the conductive buses 120 may consist of one conductive yarn, e.g., with a resistivity of, e.g., 0.1 to 100 ohm per meter, or of multiple (e.g. two or more) conductive yarns, thus to reduce resistance and to ensure a more positive connection between the electric conductance heating elements and the conductive buses. The conductive bus 120 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. The conductive paste may be applied as a stripe to a surface of the woven body 124 in electrical conductive relationship with the electrical conductance heating elements 30, and then connected to the power source. (If necessary, the conductive filaments of the electrical conductance heating elements 30 may be exposed, e.g., a covering yarn may be removed with solvent or localized heat, e.g. by laser; or the covering yarn may be manually unraveled, thus to facilitate accessibility to conductive filaments of each of the electrical conductance heating yarns.) More preferably, the conductive buses 120, in the form of conductive yarn or thread, are attached upon the surface 122 of the woven body 124, e.g., by stitching, e.g. embroidery stitching, sewing, or with an adhesive, such as by laminating. Alternatively, referring to
A conductive bus of the woven fibrous electric heating article of the invention is preferably flexible, corrosion resistant, with low electrical resistivity, e.g. 0.1 ohm/meter to 100 ohm/meter, and mechanically durable. Other considerations include cost, availability in the market, and ease of fabrication. The conductive bus may thus have the form of a wire, e.g., stranded, twisted, or braided; a conductive-coated textile, e.g., a coated filament or fabric, or a woven ribbon; a foil tape, e.g., adhesive backed, with or without a conductive backing; a conductive-filled resin, e.g., disposed in a continuous line; or a hybrid textile, e.g., including tinsel wire or stainless steel filaments, in twisted, braided, stranded, woven or knitted configuration. As mentioned above, the conductive bus may also have the form of a single yarn, or two or more generally parallel yarns, woven into or stitched upon the fabric body, or a tape or band of conductive material attached upon the surface of the fabric. In a presently preferred form, the conductive bus may be a narrow woven element, incorporating silver-coated copper tinsel wire, either multi-strand or individual strands in parallel, with periodic floats provided for contact with the conductive yarns, or a narrow woven element pre-coated with conductive thermoplastic in a stripe pattern, with discontinuous diagonal stripes to provide flexibility and ensure registration with conductive yarns. The conductive bus may also extend in multiple elements extending generally parallel in the edge region of the fabric, with similar or different lengths, to connect to distinct sets of electrical conductance heating yarns, in this manner reducing the level of electrical current carried by each conductive bus in the region close to the source of electrical power. In the case of conductive buses of different lengths, the resistivity of the individual conductive buses may be different.
The conductive bus 120 is preferably mounted upon the surface of the woven body 124 in a manner to provide strain relief For example, strain relief attachment may be provided by sewing the conductive bus 120 to the woven body 124, by tacking the conductive bus 120 upon the surface of the body 124 with mechanical fasteners, such as snaps, grommets, staples, or rivets; by over-molding in place strain relief injection-molded “buttons”; or by incorporating strain relief and electrical connection rigid filled resin having low viscosity. The electrical conductance heating yarns 30 and conductive bus 120 may be connected electrically by conductive welding or paste; rivets, snaps, or metal holders or fasteners; interlacing, knitting or weaving in, or combinations of the above.
The completed circuit is next connected to a power source to supply electrical power to the electrical conductance heating elements for the required amount of heat generation. For example, referring to
The resulting product is a woven fibrous electric heating article, e.g., an electric blanket 90 inches by 90 inches with a 24-volt power supply, with features not available with blankets currently on the market. In a preferred embodiment, the fibrous woven article has the characteristics of being: flexible, foldable, portable, able to be washed frequently, comfortable, with zone heating and low voltage (for increased safety).
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, woven fibrous electric heating articles of the invention may be formed by any suitable method that results in a woven body formed of non-conductive fibers and conductive elements capable of generating heating when connected to a source of electrical power, and, as desired, or as designed, with non-conductive fibers being exposed, e.g., in predetermined regions, for finishing at one or both surfaces to create fleece, the finishing being performed in a manner to avoid damage to electrical conductivity performance of the electrical conductance heating elements joined with the non-conductive fibers in the woven body.
Referring to
Accordingly, other embodiments are within the following claims.
This application is: a continuation-in-part of U.S. application Ser. No. 09/791,237, filed Feb. 23, 2001, now pending, which is a continuation-in-part of U.S. application Ser. No. 09/697,100, filed Oct. 26, 2000, now U.S. Pat. No. 6,373,034, which is a continuation-in-part of U.S. application Ser. No. 09/395,326, filed Sep. 13, 1999, now U.S. Pat. No. 6,160,246, issued Dec. 12, 2000, which is a division of U.S. application Ser. No. 09/296,375, filed Apr. 22, 1999, now abandoned and is a continuation-in-part of U.S. application Ser. No. 09/592,235, filed Jun. 12, 2000, now pending; and a continuation-in-part of U.S. application Ser. No. 09/703,089, filed Oct. 31, 2000, now U.S. Pat. No. 6,307,189, issued Oct. 23, 2001, which is a division of U.S. application Ser. No. 09/468,627, filed Dec. 21, 1999, now U.S. Pat. No. 6,215,111, issued Apr. 10, 2001; the complete disclosures of all of which are incorporated herein by reference.
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| Number | Date | Country | |
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| Parent | 09468627 | Dec 1999 | US |
| Child | 09592235 | US | |
| Parent | 09296375 | Apr 1999 | US |
| Child | 09395326 | US |
| Number | Date | Country | |
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| Parent | 09791237 | Feb 2001 | US |
| Child | 10082465 | US | |
| Parent | 09703089 | Oct 2000 | US |
| Child | 09791237 | US | |
| Parent | 09697100 | Oct 2000 | US |
| Child | 09703089 | US | |
| Parent | 09592235 | Jun 2000 | US |
| Child | 09697100 | US | |
| Parent | 09395326 | Sep 1999 | US |
| Child | 09468627 | US |
