Patent Grant
10487423
The present invention relates to a sensory yarn for use in textile material.
A sensory yarn commonly has a thread core with a longitudinal central axis extending along the length of the yarn, referred to as the direction of extent. The thread core may be monofilic or made of several fibers or filaments. Preferably, the thread core is elastically extendible in the direction of extent. The extensibility of the sensory yarn may be adapted to the material in which the sensory yarn is integrated, and thus, may vary within a wide range.
In order to produce a capacitive component a first conductor and a second conductor are wound in a screw-like or helical form relative to the direction of extent. The sensory yarn may be configured as a twisted yarn or as a wrapped yarn. Consequently, the two conductors can be wound in and/or around the thread core. The two conductors are electrically insulated relative to each other. For example, at least one of the two conductors can be insulated by a varnish or a coating around the electrically conductive core.
For example, a sensory yarn has been described in DE 10 2008 003 122 A1. In that reference, the yarn is disposed for the detection of tensile stresses in a medical knit fabrics or knits. The yarn has a core thread around which—in one exemplary embodiment—a covering thread may be wound. If the yarn is curved or stretched in its direction of extent, the electrical property of the yarn changes, i.e., for example the electrical conductivity and/or capacitance. For example, the covering thread may be a bimetal thread.
DE 103 42 787 A1 describes an electrically conductive yarn, wherein at least one electrically conductive thread is wound around a core thread.
DE 10 2006 017 340 A1 discloses another electrically conductive yarn. A non-conductive multi-filament yarn that, preferably, is to deposit itself in a planar manner on the core thread is additionally wound around the electrically conductive thread that is wound around the core thread, so that, in the event of a contact of two electrically conductive yarns in a textile material, there will not form an inadvertent electrically conductive contact.
Presently, sensory textile materials are used in the diverse fields of applications. For example, such sensory textile materials are able to detect pushing forces, pulling forces or the like. In many applications, localization of the affecting force is advantageous or necessary. Frequently, the sensory yarns are incorporated in a dense matrix-shaped pattern of the textile material so that a two-dimensional pattern of intersecting sensory yarns is formed. If a force acts at a specific location on this surface or if an object approaches this surface, it is possible—depending on the density of the sensory yarn—to determine a location of the force or the approach of an object by means of the sensory matrix.
The costs of manufacture for such sensory textile materials are great, as a result of which the textile material becomes accordingly expense. As a result of this, the use of sensory textile materials continues to be minimal.
It is an objective of the present invention to provide an improved sensory yarn. The subject sensory yarn may be configured as a wrapped yarn having a thread core or as a twisted yarn. The sensory yarn has at least one first conductor and at least one second conductor, wherein at least one of the two conductors is helically wound relative to the direction of extent of the sensory yarn. In doing so, the two conductors may be wound on the thread core—i.e., intersecting and/or with the same winding pitch next to each other without intersecting—or the thread core may have or form one of the two conductors (i.e. wrapped yarn). In the case of a twisted yarn, one or both conductors may be helically wound.
The two conductors are electrically insulated relative to each other, as a result of which the conductor pair of the at least one first conductor and at least one second conductor together with additional yarn components, for example the thread core, forms a capacitive component. The additional yarn components or the thread core represent the non-conductor of the capacitive component.
This capacitive component has a capacitance per unit of length that changes in the direction of extent of the thread core and thus in the direction of extent of the sensory yarn. The change of the capacitance per unit of length of the capacitive component may be continuous and/or in steps or in sections. For example, the capacitive component may have, in the direction of extent, successive yarn sections exhibiting different capacitances. In doing so, the capacitance per unit of length may be constant in a yarn section. It is also possible—at least sectionwise—to continuously change the capacitance per unit of length of the capacitive component, for example, to initially steadily increase from a minimum value to a maximum value of the capacitance per unit of length and/or to decrease from the maximum value to the minimum value of capacitance per unit of length. The pattern of continuously or sectionwise changing capacitance per unit of length may repeat as of a specific yarn length of the sensory yarn.
Two random sections of the sensory yarn may exhibit different capacitances per unit of length when they exhibit capacitances different from one another while having the same length.
With the use of the sensory yarn it is possible to detect a force acting on the sensory yarn, for example a pushing force and/or pulling force, a force change, a media charge with a liquid or vaporous medium or the approach of an object, a temperature change (due to the position change of the sensory yarn), or the like.
Due to the capacitance per unit of length that changes in a targeted manner in the direction of extent it is possible to achieve a local resolution in the direction of extent. The reason being, that an effect to be sensed and that is acting on the sensory yarn now depends not only on the type and the degree of the effect but also on the location at which the effect acts on the sensory yarn. For example, the total capacitance of the sensory yarn having a specific length changes depending on the capacitance per unit of length exhibited by the capacitive component at the location of effect. Consequently, it is possible by means of the sensory yarn according to one embodiment of the invention to provide a sensory textile material part, wherein the sensory yarns are no longer crossed in a matrix but can be arranged only parallel to one another in one direction. In the event of an effect that is to be sensed, the total capacitance of a sensory yarn incorporated in the textile material part changes. Generally, for example when the textile material is touched or when the textile material part is approached, the total capacitances of several sensory yarns are impaired. As a result of the fact that the capacitance of each capacitive sensor of a sensory yarn changes in the direction of extent, this allows a detection of the position. The production of a sensory textile material part may be clearly simplified. In particular, the electrical contact of a sensory textile material part on a single side may be sufficient because the sensory yarns are no longer superimposed in a crossed manner in two directions as before. As a result of this, the manufacture of a sensory textile material is simplified.
Preferably, the capacitance per unit of length of the capacitive component in a first yarn section is different from the capacitance per unit of length in another, second, yarn section of the sensory yarn. In particular, at least two yarn sections may be present, each being associated with a substantially constant capacitance per unit of length. For example, the first yarn section may have a first capacitance per unit of length, the second yarn section may have a second capacitance per unit of length, a third yarn section may have a third capacitance per unit of length, etc. Between each of such yarn sections exhibiting different capacitances per unit of length, there may be a transition section in which the capacitance changes steadily. Depending on the measure that is used for changing the capacitance per unit of length, it may be necessary—due to manufacturing engineering reasons—to provide such a transition section. The reason being that it is not always possible to increase or decrease the capacitance per unit of length at one location of the sensory yarn in jump-like fashion.
In the exemplary embodiment, the change of the capacitance per unit of length in the direction of extent is at least 0.03 pF and/or a maximum of 250 pF. For example, two or more yarn sections may be present, wherein the capacitance of successive yarn sections changes—with optionally interposed transition sections—by at least 0.03 pF, respectively. The difference between a yarn section exhibiting a minimum capacitance per unit of length and a yarn section with a maximum capacitance per unit of length may be up to 250 pF or greater.
In order to change the capacitance per unit of length of the capacitive component in the direction of extent, it is possible to use one or more measures. In one exemplary embodiment, changing the capacitance per unit of length can be effected in that a change of the number of windings per unit of length of the thread core is provided. Alternatively or additionally, it is also possible to change the pitch of the helical winding of the at least one first conductor and/or the at least one second conductor. The pitches of the helical windings of the two conductors may be the same and/or exhibit the same value in a shared yarn section. However, it is also possible for the pitch of the two conductors in a shared yarn section to be different in view of the amount and/or the value.
An additional or alternative measure for changing the capacitance per unit of length of the capacitive component can be accomplished in that the relative electrical permittivity of the thread core changes in the direction of extent. This may be done, for example, in that different materials or material combinations having a different relative permittivity of the thread core, respectively, are used. For example, a plastic material used for the manufacture of the thread core may be sectionwise combined or doped with at least one additional material in order to change the relative permittivity. A change of the relative permittivity can be achieved by the material and/or by the proportion of doping relative to the basic material of the thread core.
In one exemplary embodiment the thread core may contain a polymer material or consist of a polymer material. For example, the thread core may contain polyurethane and be made of elastane as in one exemplary embodiment. The at least one first conductor and/or the at least one second conductor may contain metal and be made of wires, in particular copper wires. For electrical insulation, the wires may be lacquer-coated or provided with a coating. Preferably, the conductors have a diameter of a maximum of 0.1 mm.
In one exemplary embodiment, the at least one first conductor and/or the at least one second conductor may extend in a multi-start helical line around the thread core.
As an alternative to the previously described embodiments, the two conductors may also be formed by a conductive layer that is applied to the thread core, wherein the conductive layers are electrically insulated relative to each other. Due to the insulator of the thread core and/or an additional layer, it is possible to change the capacitance per unit of length. Alternatively or additionally, the form also may be varied and, in particular, the layer thickness of at least one of the conductive layers may be varied so as to change the capacitance per unit of length.
According to a further embodiment, the capacitance of the sensory yarn may vary in the direction of extent as described hereinabove or may alternatively also be constant. In this embodiment, the sensory yarn comprises a photosensitive material. The photosensitive material may be a component of a thread core or be arranged on the thread core. Due to one or both of the effects described hereinafter, the photosensitive material may change the total capacitance of the capacitive component of the sensory yarn:
As a result of this, the total capacitance of the capacitive component of the sensory yarn changes. Consequently, light impinging on the sensory yarn can be detected.
For the effect described under b) above, it is possible to use, for example, a zinc sulfide doped with copper (ZnS:Cu) or a doped semiconductor material. The free charges that can move in a restricted manner in the material form—independently of the intensity of the incident light—dipoles in the electrical field, as a result of which the relative permittivity and the thus measurable total capacitance changes.
The photostrictive material may be a polymer material and/or a semiconductor material and/or a ferroelectric material and/or a magnetic material and/or a magnetoelectric material. For example, the thread core may be made of a polymer material that is doped with a semiconductor material. Additionally or alternatively to being doped with a semiconductor material, the polymer material may also be doped with another suitable material, for example bismuth ferrite.
A sensory textile material part may comprise at least one sensory yarn according to the first inventive solution and/or at least one sensory yarn according to the second inventive solution. The textile material may be a knit or a woven material. The sensory yarns may be incorporated in a woven fabric, for example as the weft thread or as the warp thread. The sensory yarns may also be placed in a woven material or a knit material and held by the non-sensory yarns or threads in the textile material. Preferably, the sensory yarns are arranged in one direction of the textile material without cross-overs, preferably in the direction of the weft threads. In one knit material, the at least one sensory yarn may be incorporated as the ground threads.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings.
While the invention is susceptible of various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention.
Referring now more particularly to
At least one first conductor 12 and at least one second conductor 13 are wound around the thread core 11. In the exemplary embodiments illustrated here, respectively one single first conductor 12 and one single second conductor 13 are shown. In modification thereof, it is also possible for several first conductors 12 and second conductors 13, respectively to be present.
The conductors 12, 13 comprise an electrically conductive material, in particular metal, or they are made of such a material. In the exemplary embodiment, the conductors 12, 13 are made of a metallic wire, preferably a copper wire. In order to prevent an electrical connection between the two conductors 12, 13 and between the conductors 12, 13 and the thread core 11, the outside surface of the conductors 12, 13 is provided with an electrically insulating coating or an electrically insulating lacquer. In accordance with the example, the conductors have a diameter of up to 0.1 mm or 0.2 mm.
In accordance with the example, the first conductor 12 and the second conductor 13 form a conductor pair 14. The conductor pair 14 is a component of a capacitive component 15. The capacitive component 15 of a sensory yarn having a specific length exhibits a total capacitance CG.
The capacitance of the capacitive component 15 depends on the constructive design of the sensory yarn 10. The sensory yarn 10 may be manufactured in almost any desired length and wound on a spool. When the sensory yarn 10 is incorporated in a textile material part 16, a sensory yarn 10 having a specific length exhibits the total capacitance CG. This total capacitance CG changes when a load is applied to the sensory yarn 10, for example a force such as a pushing force or a pulling force. Due to a length change of the thread core 11 that acts as the insulator for the capacitative component 15 and/or due to a relative shift of the at least one first conductor 12 with respect to a second conductor 13, the total capacitance CG may change. As a result of this, the sensory yarn thus represents a capacitive sensor. Via an evaluating unit 17 that is electrically connected at one end of the sensory yarn 10 to the two conductors 12, 13, the actual total capacitance CG can be determined. Based on this, an effect on the sensory yarn 10 can be detected. The detectable effect on the sensory yarn 10 can be one or more of the following effects:
Considering the exemplary embodiments illustrated by
In modification of the sectionwise constant capacitances Cl per unit of length l, the capacitance Cl per unit of length l may also be continuously increased or decreased, at least sectionwise. For example, the capacitance Cl per unit of length l may be steadily increased from a minimum value of, e.g., 10 pF to a maximum value of 250 pF or more and/or, conversely, be steadily decreased from the maximum value toward the minimum value. Such continuously changing sections may also be provided so as to be successive in the sensory yarn 10.
Considering the embodiment of the first sensory yarn 10a illustrated by
In the exemplary embodiments of the first sensory yarn 10a the amounts of pitch for both conductors 12, 13 are the same, however, have different signs. As a result of this, intersecting locations in the windings of the two conductors 12, 13 are formed. It is not absolutely necessary that the amounts of pitch for the two conductors 12, 13 in a yarn section 21 be the same, rather the amounts of pitch of the two conductors 12, 13 may also be different from one another. Furthermore, between the two adjacent yarn sections exhibiting different capacitances Cl per unit of length l, it is also possible to change only the pitch of the first conductor 12 or the second conductor 13.
In the preferred exemplary embodiments described herein, the permittivity that changes the material is incorporated as the doping material in the base material of the thread core 11. Furthermore, it would also be possible to provide a coating enclosing the thread core 11 and the conductors 12, 13, said coating containing or consisting of a material that changes the permittivity.
It will be understood that it is further possible to vary the permittivity ε, as well as the pitch of the windings, to change the capacitance Cl per unit of length l and to thus combine with each other the exemplary embodiments of the first sensory yarn 10a as illustrated in
With the use of the first sensory yarn 10 it is possible to produce a sensory textile material part 16 as schematically illustrated by
As is schematically shown in
In addition to the parallel-arranged sensory yarns 10, the textile material 16 comprises one or more conventional textile threads 25. The non-sensory textile thread 25 may be used for the stitch formation (
The representations of
The second sensory yarn 10b contains a photosensitive material 30. This photosensitive material 30 may be applied to any location on the sensory yarn 10 or be incorporated in the sensory yarn 10. In the preferred exemplary embodiment described herein the photosensitive material 30 is incorporated as a doping material in the base material of the thread core 11. As an alternative thereto, the thread core 11 may also consist of photosensitive material. Furthermore, it is also possible to provide a coating that encloses the thread core 11 and the conductors 12, 13, said coating containing or consisting of the photosensitive material 30.
With reference to
The photostrictive material 30 may be, for example, a polymer material, a semiconductor material, a ferroelectric material, a magnetic material or a magnetoelectric material. For example, bismuth ferrite may be used as the photostrictive material.
In the exemplary embodiment of a photosensitive second sensory yarn 10b illustrated in
The photosensitive second sensory yarn 10b can thus be used to detect the presence of incident light L or an intensity change. For example, an illumination sensor or also a brightness sensor could be implemented in this manner. Such a sensor could be integrated with the use of the sensory yarn 10b in a shading textile, for example, a sun shade or the like that is moved out of or into a retracted position as a function of incident sun light. The sensor system could thus be an integral part of a sun protection shade and a separate sensor could be dispensed with.
In both sensory yarns 10a, 10b, one of the two conductors, for example the second conductor 13, can be formed by the thread core 11 (
In all the embodiments of the first sensory yarn 10a, and preferably of the second sensory yarn 10b, at least one of the two conductors is helically would in the direction of extent E.
The first sensory yarn 10a and the second sensory yarn 10b may also be used together in a textile material part 16 when the effect of light L, as well as an object approaching the textile material part 16 and/or a force effect on the textile material part 16 and/or an effect due to a liquid or vaporous medium and/or another total capacitance CG of an effect influencing the sensory yarn 10 is to be detected.
From the foregoing, it can be seen that a sensory yarn 10 is provided having a thread core 11, around which a first conductor 12 and a second conductor 13 are helically wound. The two conductors 12, 13 are electrically insulated from each other and from the thread core 11. The two conductors 12, 13 form a capacitive component 15 together with the thread core 11. In the case of a first sensory yarn 10a, the capacitance Cl per unit of length changes in the direction of extent E of the sensory yarn. This can be accomplished by a change in the winding geometry of the first conductor 12 or of the second conductor 13 or by a change of the relative permittivity c of the sensory yarn 10. A second sensory yarn 10b has photosensitive material 30, and therefore a length change can be caused by incident light L. As a result of a length change or other deformation of the sensory yarn 10a, 10b, the total capacitance CG of the sensory yarn 10a, 10b in question changes, which can be determined by means of an evaluating unit 17.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2014 103 978 | Mar 2014 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2015/055985 | 3/20/2015 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/144597 | 10/1/2015 | WO | A |
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