Background of the invention

The invention relates to a woven or knitted band that comprises a lat eral direction and a longitudinal direction, and the structure of the band compris es electrically conductive yarns in the longitudinal direction of the band.

A knitted, woven, or twined textile band is known from publication US 6727197, for use in connection with, for example, wearable electronics or intelli gent fabrics. The band comprises optical or electrically conductive fibres.

From publication US 2013/0062095, a flat, woven cable is known to be used in connection with clothing. The cable consists or longitudinal yarns and a lateral, flexible fibre. The longitudinal yarns are formed of an elastic filament, con ductors spirally wound around the filament, and an insulating layer.

The problem with the arrangement described first in the above is that the band is relatively stiff and does not yield in the longitudinal direction. The problem with the arrangement described second in the above is that it is difficult to disassemble conductors wound around the filament to reveal the ends of the conductors.

Brief description of the invention

lt is thus an object of the invention to develop a product which may be relatively freely stretched and which, when unloaded, returns to its substantially original dimension. The object of the invention is achieved by a product charac terised by what is disclosed in the independent claims. Preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on the band being stretchy in its longitudinal di rection and reversible from a stretched condition. The band structure comprises longitudinal elastic yarns which are arranged to bind to the structure as yarns separate from the electrically conductive yarns, whereby the band may be stretched without damaging the electrically conductive yarns. Binding as separate yarns from the electrically conductive yarns means that elastic yarns and electri cally conductive yarns do not form an element containing both components in the structure, but both the electrically conductive yarn and the elastic yarn may bind to the structure as separate yarns. However, an electrically conductive yarn and elastic yarn may bind into each other in the structure. An advantage of an elastic band is that is conforms to the surface to which it is fixed ln addition, the band has all the usage properties needed in connection with clothing, such as washability. The uses for the band include conductors used in connection with wearable electronics, intelligent fabrics, or robots. Applications for the band in clude medical technology, healthcare, protective clothing, warning systems inte grated into clothes, and instruments athletics. The band may be used, for example, as a conductor between a measurement electrode in a piece of clothing and an in formation gathering unit or in connection with battery or transformer operated devices.

As electrically conductive yarns, all yarns having an adequate conduc tivity from the point of view of the use may be used, but particularly advantageous are metal threads, such as copper wires. Metal threads are easy to connect to mat ing surfaces, such as electrodes in the clothing. Metal threads may consist of one or more electrically conductive metal filaments and an insulating layer around them.

According to an embodiment, the band may be manufactured by weav ing, in particular by weaving with the Jacquard technology. Jacquard technology refers to a weaving technology in which each warp thread may be lifted inde pendently of other warps, in other words, each warp thread may be individually controlled. When the band is being woven, elastic yarns are tensioned, whereby the yarn, when untensioned, shortens in the longitudinal direction into wavelike as concerns its cross-section, or into a structure otherwise shortened as to its length. When the band is to be fixed to another mating surface, it may be stretched as needed.

A woven band, such as a band woven with the Jacquard technology, consists of a basic structure and a connecting area at both ends of the band. The basic structure may be a longitudinal tubular element within which the electrically conductive yarn resides. There may be a plurality of parallel tubular elements. The electrically conductive yarn may bind to the basic structure inside the tubular el ement, or it may run freely inside the tubular element. The basic structure does not necessarily have any tubular elements, but the electrically conductive yarn / conductive yarns runs / run protected inside the weave of the band either binding or not binding to the basic structure of the yarn.

A specific advantage of a woven band is that the width of the band and the number of electrically conductive yarns may be increased or decreased as needed by introducing more warp threads or not using some of the warp threads ln addition, the length of the yarn may be adjusted exactly as needed, in other words, the basic structure may be woven to a length suitable for each purpose. An advantage of a yarn woven with the Jacquard technology is that the electrically conductive yarns may at a particular manufacturing stage be woven so that they do not bind to other yarns but remain as free yarns on the band surface. When the band is cut at such a point, the electrically conductive yarns are ready to be connected to the places between which they conduct electricity.

According to an embodiment, the band may be woven with the warp knitting technology. Warp knitting technology refers to a knitting technology in which the yarns that form loops run in the longitudinal direction of a fabric. The simplest warp knitting weave is a chain weave in which the yarns form loop chains separate from each other. A uniform knit is formed by a tricot stitch which binds to the adjacent loop in different lines. Other warp knitting weaves include the satin and velvet stitches, for example. The weave of a warp knit may consist of the aforementioned basic weaves, their combinations, or variations.

The band is manufactured by the warp knitting technology so that the basic weave is formed by the warp knit which binds the electrically conductive yarns and elastic yarns to the structure. The warp knit may have a weft thread that binds the band in the lateral direction. The electrically conductive yarns are bound by means of the basic weave so that the electrically conductive yarns form a plu rality of adjacent yarn paths in which the yarn runs in the longitudinal direction of the band, zigzagging from right to left and left to right. The elastic yarns run sub stantially straight in the longitudinal direction of the band, with the basic weaves binding them in place.

Brief description of the drawings

The invention will now be described in more detail in connection with preferred embodiments and with reference to the accompanying drawings, in which:

Figures la and lb show a manufacturing pattern of a band according to the invention;

Figure lc is a side view of a band according to the invention;

Figure 2a and 2b are principled images of the stretching mechanism of a band according to the invention;

Figure 2c shows a manufacturing pattern of a band according to the in vention;

Figures 3a and 3b are cross-sections of yarns according to the inven tion. Detailed description of the invention

Figures la and lb show a manufacturing pattern of the band according to the invention. The woven band comprises electrically conductive yarns, elastic yarns, and yarns forming the basic structure of the band.

Figures la and lb show warp threads 1 to 8. The warp threads 1 to 6 are yarns that form the basic structure, and they may be of polyamide, for exam ple. The fineness of the yarns may be 110 x 2 dtex, for example. The warp thread 7 is of elastic fibre material, such as elastane. The warp thread 8 is an electrically conductive yarn. The weft thread may be a yarn forming the basic structure, such as the same yarn as the warp threads 1 to 6. ln a finished product, the warp threads are usually present as multiples, in other words, the warp threads 1 to 8 are repeated in parallel a number of times in the same order. A band may have, for example, 56 warp threads of which 42 warp threads are yarns forming the basic structure, such as polyamide yarns, 7 warp threads are of elastic fibre material, such as elastane, and 7 warp threads are electrically conductive yarns.

Figures la and lb show a grid divided into four parts. The top left of the grid shows a fabric image, the bottom left shows the drawing-in of warp ends, the top right shows the raising of heald laths, and the bottom right shows the binding.

ln the fabric image, the vertical square lines are warp threads and hori zontal square lines are weft threads. A square illustrates a point where the warp and weft are one upon the other. When a square is marked, the warp thread is on the weft thread. The drawing-in of warp ends is shown in such a manner that the vertical square lines are warp threads and the horizontal lines are heald laths. The raising of heald laths is presented in such a manner that the vertical square lines are the heald laths to be raised, and the horizontal lines indicate the order of the weft threads ln binding, the vertical square lines refer to the lifters of heald laths and the horizontal ones the heald laths.

Figure la shows the manufacturing pattern of a band when the electri cally conductive yarns run inside the band. Figure lb shows the manufacturing pattern of a band when the electrically conductive yarns run freely.

Figure lc is a side view of the inventive band 1. The longitudinal direc tion of the band 1 is denoted by the arrow L. The band 1 comprises longitudinal areas A and B. Area A is formed of the structure according to Figure la, and area B is formed of the structure according to Figure lb. The length of the areas A and B and their ratio to each other may be adjusted as needed. The elastic warp threads of the band 1 are woven tensioned, whereby in an untensioned state the elastic warp threads shorten, and the area A of the band 1 seems wavelike or otherwise collapsed when seen from the side.

ln the area B, the electrically conductive yarns 2 run freely over the remaining band structures, Figure lc showing three electrically conductive yarns 2, but their quantity may vary as needed. When the band 1 is cut at the area B, the ends of the electrically conductive yarns 2 may be connected to their purpose of use. When the band 1 is cut, the cutting point is usually locked so that the electri cally conductive yarns cannot move. Locking may be performed by casting plastic to the cutting point, for example.

Figures 2a and 2b show a principled view of the stretching mechanism of a band according to the invention in a knitted band which comprises electrically conductive yarns 4, elastic yarns 3, and yarns forming the basic weave. The elastic yarns 3 are in the structure substantially straight in the longitudinal direction of the band. The electrically conductive yarns 4 run between two elastic yarns 3 zig zagging so that the band has a number of parallel elastic yarn pairs between which the electrically conductive yarn is zigzagging, forming yarn loops substantially transverse to the longitudinal direction of the band, as shown in Figures 2a and 2b. The basic weave of the band binds both the elastic yarn 3 and the electrically conductive yarn 4 as well as the elastic yarn pairs into a uniform band. The listings of the band on both edges of the band are formed of the elastic yarn 3 and the basic weave binding the elastic yarn.

ln Figure 2a, the band is in an untensioned form. The electrically con ductive yarn 4 binds to the elastic yarns 3 by means of the basic weave at weave points 5 which may be of another type than that shown in Figures 2a and 2b. When the band is stretched in the direction of the arrows T as in Figure 2b, the elastic yarns 3 yield and the electrically conductive yarns 4 enable the stretching when the substantially transverse yarn loops yield.

Figure 2c shows a manufacturing pattern of a band according to the in vention, manufactured with the warp knitting technology. The basic yarn may be, for example, a 167 dtex polyester yarn. The elastic yarn may be a natural or syn thetic rubber yarn. The electrically conductive yarn may be, for example, an insu lated copper wire whose copper core comprises a plurality of thin copper wires.

Figures 3a and 3b show some alternatives of an electrically conductive yarn 4 of the invention. The yarn 4 comprises an insulating layer 6 and an electri cally conductive core 7. The electrically conductive core 7 may be of copper or an- other metal. The electrically conductive core may have one electrically conductive filament or a number of electrically conductive filaments 7a, as shown in Figure 3b. The electrically conductive filaments 7a may be inside the insulating layer 6 at another position than shown in Figure 3b, and the number of filaments 7a in the electrically conductive yarn 4 may vary.

A person skilled in the art will find it obvious that, as technology ad vances, the basic idea of the invention may be implemented in many different ways. The invention and its embodiments are thus not restricted to the above- described examples but may vary within the scope of the claims.