TECHNICAL FIELD OF THE INVENTION

The invention relates to heating elements. More specifically, the invention is related to a knitted assembly that is capable of converting electrical power into thermal energy, said knitted assembly being suitable for use in a textile article such as a garment.

BACKGROUND OF THE INVENTION

Heating elements that may be incorporated with textiles are widely available and are useful in various different situations, for example during sports such as diving, while moving outdoors in cold climates, or even everyday indoor use for comfort. Many of these have poor efficiency, and substantial amounts of electricity are required. The heat provided by traditional convectional heating solutions is also largely local and efficiently heats only e.g. the body part that the heating element is in physical contact with. The prior art introduces textile heating elements that are complicated to manufacture, as for example the production of garments involve many different steps, such as production of the heating element, which may be done in many stages, and its incorporation into a garment afterwards. Power consumption of prior art solutions can additionally be problematic. Depending on how the electrical power is delivered to the heating elements, the solutions might require large batteries and/or frequent replacement or recharging of them.

SUMMARY OF THE INVENTION

The object of the present invention is to offer advantages over the known prior art, which can be achieved by the features of the independent claims. According to an embodiment, a knitted assembly for a textile article, optionally a garment, comprises conductive material and heating material. The conductive material is advantageously configured to supply electrical power to the heating material. The knitted assembly additionally comprises interconnected chains of loops that define at least one substantially three- dimensional cavity. The heating material is configured to convert electrical power supplied by the conductive material into thermal energy and at least part of the loops defining the cavity comprise the heating material. A manufacturing method is also provided for manufacturing the knitted assembly, wherein the manufacturing method comprises steps of knitting chains of loops to define at least one substantially three-dimensional cavity and arranging conductive material and heating material so as to supply electrical power to the heating material via said conductive material. The method also comprises arranging the heating material into at least part of the loops that define the cavity, so that said heating material is configured to convert electrical power supplied by the conductive material into thermal energy. Yet, a computer program comprising program code means adapted to, when the program is run on a computerized knitting machine, cause said knitting machine to execute the manufacturing method for manufacturing the knitted assembly is further provided.

One embodiment of the invention involves the production of heat through far infrared radiation, which is an effective method for heating a human body, for instance, as the infrared waves are converted to heat in the body, and the heat is distributed through the body via the bloodstream. This entails that the body may be heated more comfortably and efficiently than through the use of traditional heating elements. Heating elements may in some cases be located near large muscle groups, and the whole body may subsequently be efficaciously heated.

As the heating material is provided in connection with the cavity, when supplied with electrical power the heating material may heat the air inside the cavity, which may provide heat insulation for e.g. a human user of the invention that can be wearing for instance a garment comprising the knitted assembly. The cavity may additionally comprise heat reflecting material, which may add to the heat insulation, and bring about even more effective heating with the same amount of electrical power. Through the cavities and the optional reflective material, the claimed invention may offer more effective heat insulation and more effective heat production with the same amount of electrical power as compared to prior art solutions.

As the heating assemblies are produced entirely through knitting, they are thoroughly flexible and may accommodate any shape. Advantageously, a knitted assembly according to embodiments of the present invention is manufactured through a method utilizing computerized knitting techniques which may be referred to as 3D-knitting. These techniques enable the production of three-dimensional seamless knit structures. Using the method of 3D-knitting, all parts of the heating assembly and also optionally a complete textile article including the heating assemblies, such as a garment, may be produced simultaneously and seamlessly. This may reduce the steps and thus time, cost, and amount of labor required to manufacture heating textiles. Heating textiles may be essentially thin if desired, and still provide ample heating power. Through the invention, it is possible to produce garments with high heating capabilities that are comfortable and not bulky.

A knitted assembly and textile article according to embodiments of the invention may have heating elements that are variable in size. A knitted assembly and thus a heating element or a cavity or cavities may be relatively small compared to the textile article or a textile article may comprise one knitted assembly that may essentially make up most of or all of the textile article. A textile article may also comprise one or several knitted assemblies.

The cavities comprised in the heating assemblies may provide novel ranges of capabilities. Through 3D-knitting, the cavities may also comprise further complex structures, e.g., cavities within cavities.

The present invention may be used for garments, but also any other textile article or heating purpose. As an example, a soft package for transport of fragile goods that should be kept at a specific temperature may be manufactured according to an aspect of the invention. Other examples of textile articles may be a fabric, a seat cover, a blanket, a shoe, and an insole.

The exemplary embodiments presented in this text are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this text as an open limitation that does not exclude the existence of also unrecited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific example embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Next the invention will be described in greater detail with reference to exemplary embodiments in accordance with the accompanying drawings, in which:

Figure 1 illustrates an exemplary knitted assembly according to an embodiment of the invention, Figure 2 exhibits a knitted assembly according an aspect of the invention, showing the associated loops,

Figure 3 shows an alternative view of an exemplary knitted assembly,

Figure 4 illustrates an alternative embodiment of the present invention,

Figure 5 shows an alternative embodiment of the present invention, Figure 6 shows an alternative embodiment of the present invention,

Figure 7 shows an alternative embodiment of the present invention,

Figure 8 shows an alternative embodiment of the present invention, and

Figure 9 gives one more alternative embodiment of the present invention.

DETAILED DESCRIPTION Figure 1 gives an exemplary knitted assembly 100 according to an embodiment of the invention. In the cross-sectional view of Fig. 1 , individual loops are not shown, as the figure is a conceptual figure to illustrate how different materials may be arranged in the assembly. In this embodiment, a support material 102 forms a majority of the structure of the assembly 100 and also cavities 108. The support material 102 may comprise an electrically insulating material such as natural fibers, artificial cellulose based fibers, or synthetic fibers. In garments, for example, the whole inner surface of the garment which faces the skin of the wearer, may be made of the support material 102. This could ensure that a garment or textile article is comfortable and safe for the user.

Cavities 108 may be substantially three-dimensional structures that are preferably defined by chains of interlocking loops, which will be expressed in more detail below. The interlocking loops may comprise for instance a support material 102, conductive material 104, heating material 106, or thermally reflective material 1 10. The cavities 108 may be constructed in any size or shape. The term "cavity" may refer to an essentially hollow structure or a structure that may comprise any material within it.

Conductive material 104 is provided to enable delivery of electrical power to heating material 106. The conductive material 104 may comprise for instance copper, silver, gold, or a semiconductive material. The conductive material 104 may be arranged in a knitted assembly to form electrically conductive portions that may essentially act as electrical wires or conductors. The heating material 106 is configured to convert electrical power supplied by the conductive material 104 into thermal energy. The heating material 106 is preferably comprised in at least part of the loops that define one or more cavities 108. The heating material 106 may be a material that acts as a resistor for electricity, converting the electric power to thermal energy. In preferred embodiments, the heating material 106 is selected so that it may emit far infrared radiation. For example, the heating material 106 may comprise tungsten, carbon, ceramic, iron, chromium, or aluminium. In some embodiments the heating material 106 may comprise a semiconductive material. The heating material 106 may also comprise a composite material. A portion of the knitted assembly 100 that comprises several interconnected loops that comprise the heating material 106 may form a heating element or heating resistor.

In advantageous embodiments, a thermally reflective material 1 10 is also comprised in the assembly, preferably in one or more cavities 108 in a portion of loops that oppose the heating material 106. The reflective material 1 10 is configured to reflect heat and may comprise for example oxides, sulphates, carbonates, phosphates, or silicates.

In the embodiment of Fig. 1 , the heating material 106 is arranged inside a cavity 108 in a manner in which thermal radiation 1 12 may be emitted from it to a first side 1 14 of the assembly 100, which may face a possible user or wearer of a textile article comprising the knitted assembly 100, heating the user. Thermal radiation 1 12 is also emitted into a cavity or cavities 108, and may heat the air inside the cavity. The air inside a cavity 108 may aid to insulate the heat generated by the heating material 106.

Further in the embodiment of Fig. 1 , the reflective material 1 10 is arranged inside a cavity 108 in a manner in which the thermal radiation 1 12 generated by the heating material 106 is reflected by the reflective material 1 10, so that the thermal radiation 1 12 is directed away from a second side 1 16 of the assembly 100, which may face away from a possible user or wearer of the knitted assembly 100, or any other entity that the assembly 100 may be intended to heat or keep at a certain temperature. As the thermal radiation 1 12 is reflected back from the second side 1 16 of the assembly 100, it may more efficiently heat the air inside the cavity 108 and provide more efficient heat insulation and also increase the amount of thermal radiation 1 12 that is emitted to the first side 1 14 of the assembly 100.

A textile article may comprise one or more knitted assemblies 100 depending on the embodiment. For example, if a knitted assembly is comprised in a shirt, one or more knitted assemblies may reside in areas that may cover the pectoral muscles of a user of the shirt. Thermal radiation 1 12 from the heating material 106 may then be efficiently transferred to the muscle tissue of the user.

In another embodiment, one or more knitted assemblies may be comprised in a textile article that is configured to essentially surround a target entity and keep the target entity or the air surrounding it at or near a certain temperature. Depending on the desired temperature or the target entity, characteristics of the knitted assembly 100 or the number thereof that is utilized may be varied to achieve the desired effect. Figure 2 depicts the loops 202 associated with a knitted assembly 100 in an embodiment of the invention. The loops 202 may be formed from a material arranged in the form of e.g. a yarn or thread. The knitted assembly 100 is essentially formed from the interlocking loops 202 and the loops 202 define a cavity 108 comprised in the assembly 100. A yarn or thread may comprise the support material 102, conductive material 104, heating material 106, reflective material 1 10, or a combination thereof. A yarn or thread used to form the loops 202 may comprise the same material throughout its length, or the material may differ in different portions of the yarn or thread.

The conductive material 104, heating material 106, or reflective material 1 10 may, as stated, be comprised in the support material yarn or thread or comprise the material in some other manner. For example, the conductive material 104 may be a yarn or thread that is entirely composed of an electrically conductive material or it may be a thread of some other material that is coated with a conductive material, or it may be a yarn of an arbitrary material that comprises filaments of an electrically conductive material. The same description applies also in connection with the heating material 106 and the reflective material 1 10.

Figure 2 shows an exemplary assembly or a portion thereof from two different angles. Figure 2a is equivalent to the cross-sectional view of Fig. 1 , while Fig. 2b exhibits a possible portion of a knitted assembly 100 in an embodiment. From Fig. 2b, it may be seen how the loops 202 define a cavity 108 and a portion of a cavity 108.

The knitted assembly 100 is preferably formed through knitting continuous chains of loops, which may be actualized using a computerized knitting technique. A variety of terms including but not limited to "3D", "whole- garment", "complete garment", "seamless", "circular electronic", "fully fashion", "flat bed knitting", or "knit & wear" knitting may refer to utilization of computer-driven machines (computerized knitting machines) that may manipulate knitting needles through computer-readable code to produce three-dimensional products by knitting layer upon layer. An advantage that is gained through manufacturing the knitted assembly 100 through a 3D- knitting method is that the cavities 108 fundamentally retain their shape upon stretching of the knitting assembly 100. This entails that upon use of e.g. a garment comprising a knitted assembly 100 in some embodiments, the cavity or cavities 108 may not be flattened, leading to the potential benefits resulting from the shape of the cavities 108 being preserved in possible use scenarios where a textile article may be subjected to physical manipulation involving e.g. stretching or folding.

The preferable interlocking continuous loops 202 may be seen in Fig. 2. A three-dimensional structure or cavity 108 may thus, using an aforementioned computerized knitting technique, be produced by knitting in one step and on one machine, which results in a structure that is different from that in which parts are knitted separately or on different machines and then combined, in which case the loops 202 are not interlocking in a manner which is depicted in Fig. 2. Without knitting in one step, the benefits such as obtaining cavities 108 that may essentially retain their shape or the possibility to create assemblies 100 with cavities 108 inside the cavities 108 may not be accomplished.

The structure depicted in Fig. 2b may be a portion of a knitted assembly 100 that may for example extended or multiplied to any extent so that cavities 108 are substantially tubular in shape, which is illustrated in Figure 3, where once again the loops 202 are not shown. Fig. 3 gives an embodiment of an assembly 100 comprising support material 102, conductive material 104, heating material 106, and reflective material 110. An assembly 100 may also embody a different structure along the longitudinal axis 1 18, e.g. having consecutive cavities 108 of different shapes or sizes also in this direction. An assembly 100 may also have one or more layers of cavities 108, for example so that on top of the side 1 16 depicted in Fig. 1 resides more cavities 108 or layers of loops 202. Figure 4 gives an alternative embodiment of a knitted assembly 100, demonstrating an example of how support material 102 and cavities 108 may form differing shapes, and that all materials may reside in any part of the knitted assembly 100. Again, Fig. 4 gives an advantageous embodiment, as the conductive material 104is configured to supply electric power to the heating material 106, and through provision of the reflective material 1 10, heat radiation 1 12 may be directed towards a first side 1 14 of the assembly 100, which is a side onto which heat is desired to be directed. It should be noted, however, that the reflective material 1 10 is an optional feature of the assembly. Figures 5 and 6 show further alternative embodiments of a knitted assembly 100 with differing numbers and shapes of cavities 108, depicting also the conductive material 104, heating material 106, reflective material 1 10, and thermal radiation 1 12.

Figure 7 gives one more alternative embodiment of a knitted assembly 100 comprising a number of cavities 108. Here, the conductive material 104 may not be provided in connection to all cavities 108 such as in the previous figures. The conductive material 104 may be provided in connection with only one or more of the possible cavities 108, while the heating material 106 may be arranged in at least a portion of the interlocking loops 102 that form a cavity 108 in a way that allows the electric power or electricity to be passed through the heating material 106 in order to produce thermal energy in association with a number of cavities 108. As seen in Fig. 7, the heating material 106 may be thus provided in a continuous manner in interlocking loops that connect a number of cavities 108.

The conductive material 104 may be provided at various different locations with respect to the knitted assembly 100 or to one or more cavities 108. For instance, the conductive material 104 may be provided in connection with an end portion of a tubular cavity 108. Figure 8 gives yet one more alternative embodiment of a knitted assembly 100, where cavities 108 may be e.g. substantially tubular in shape such as in Fig.3. Fig. 8 shows a cross- sectional view of a plurality of tubular cavities 108. The conductive material 104 is not shown in the figure, and it may be understood that the conductive material may be comprised at the end portions of the cavities 108, i.e., so that it is behind the heating material 106 in Fig. 8.

In other embodiments, knitted assemblies 100 or one or more cavities 108 may comprise portions that do not comprise support material 102. For example, a portion of a cavity 108 that is located on the second side 1 16 of the knitted assembly may comprise loops 202 that are knitted using the reflective material 1 10, and a support material 102 is not provided ontop. This type of knitted assembly 100 is shown in Figure 9.

It may be noted that the size of a cavity 108 compared to the knitted assembly 100 may vary, and may be either small or large. The cavity 108 may comprise any number of loops 202 and be formed using a thread or yarn with variable thickness.

In order to supply electrical power to the conductive material 104 and subsequently to the heating material 106, a knitted assembly 100 may in advantageous embodiments be coupled with a power element. The power element may be comprised in the knitted assembly 100 or be attached to it using any suitable method, for example through knitting, sewing, gluing, laminating, soldering, or use of a snap fastener or press stud.

In an embodiment, the power element may be an element that is capable of creating or discharging electricity, such as a solar panel, a battery or rechargeable battery. In the case of a battery, the knitted assembly may be configured to be coupled to the battery in a manner that may enable convenient replacement of the battery. In the case of a solar panel or rechargeable battery, the power element may be readily replaceable or it may be coupled to the knitted assembly 100 essentially permanently or semi-permanently to potentially provide more efficient coupling. The rechargeable battery may thus be recharged while it is attached to a knitted assembly 100 or it may be configured to remain coupled to the assembly 100 during recharging.

In one other embodiment, the power element may be configured to receive electrical power from outside of the knitted assembly 100 and transfer it to the conductive material 104. The electrical power may be received through wireless methods such as inductive, capacitive, magnetodynamic, or radiative techniques, and the power element that is to be coupled with the knitted assembly may be for instance a coil, a capacitor, or an antenna.

The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated.