EP1596401A1 - Elastic wiring connection - Google Patents

Abstract

The connector consists of at least one cable (14) wound in a spiral round elastic support (12). (14) Is fixed continuously to (12) so that the two move together when (12) stretches or contracts, and there is no relative movement between the two, which can have an outer coating of an elastic material. The cables can be in the form of undulating parallel wires with no contact between them, and with the undulations having a regular amplitude and frequency. An independent claim is also included for a method of making the elastic connector.

Description

TECHNICAL AREA

The invention relates to links wired elements in an environment undergoing deformations.

In particular, the invention applies to the connectivity in compounds undergoing elastic deformations.

STATE OF THE PRIOR ART

Electronic development and computing has led to a multiplication of connections electric, more commonly known as connectivity. Many fields require stretchable connectivity due to relative movements that the connected elements undergo.

One of the approaches for materials sensitive is the release of the wires in the area of movement: for example, for articulated arms (as in industrial robots), the wires are attached to the arms, but they are left free at level of the joint, where they remain apparent or are inserted in a very wide sheath. This solution however, is only suitable for joints simple, whose location is precise, of great size and for protected elements and joints by their location.

One of the solutions envisaged to avoid previous flying leads involves the passage of connection wires in a preformed spiral sheath, thus forming a flexible cord, the most Representative is the telephone wire. The geometry of the sheath allows elongation of the cord and a return to its initial form when the elongation effort ceases. This solution, however, has the disadvantages noticeable bulk and fatigue of forming during uses. In addition, the movement between the wires and the sheath can cause a shear.

Another solution is manufacturing resins and / or gums possessing in themselves electrical properties, for example through the presence of conductive particles distributed within them: the conductive polymeric substrate is then used directly as connectors. However, during a elongation, the support sees its form change: particular, in the simple case of a band, during a lengthening, thickness and width decrease. This modifies the distribution of the conductive particles, and the substrate resistance is not constant, with therefore a modification of the electrical signal.

There is thus a need for connectivity so-called "elastic" in which the yarn retains electrical properties, in particular resistance and impedance, predetermined when the medium in which he finds himself deformed. Moreover, there is a need to ensure a better longevity to wiring connections used with non-rigid supports, longevity burdened by the shear relative displacement of the two elements.

STATEMENT OF THE INVENTION

The present invention proposes, among other advantages, to overcome the disadvantages inherent to existing solutions for the implementation of place of inextensible electrical wires in deformable media.

More generally, the present invention relates to elastic components comprising elongated elements, in the form of wires or cables, plus generally called "sons" afterwards, who are not not necessarily elastic, associated with a support elastic, as well as their manufacturing process. Under one of its aspects, the geometry of the wired elements of a component according to the invention is such that, when the elastic deformation of the support, they accompany the alteration of the support without however suffering from relative motion relative to the support at the level of the interface between wired elements and support. Because of this solidarity, which can be described as continuous, wires with the support, no force of shear does not intervene, and so the component remains operating even after a number of deformation cycles important.

In one aspect, the invention relates to an electrical connection, that is to say of which the wired elements are cables or wires electric, preferably inextensible to keep constant and defined electrical properties. However, other elements are possible, of which for example optical fibers.

The material of the support is chosen in depending on the use and in particular the degree desired elongation. Preferably, the material is isotropic. In the medical field, we could example to recommend the silicone; a favorite choice for the electrical connections is the polyurethane, which allows a good integration of the wire sleeves electrical and has elasticity properties known and controlled.

In order to increase the integration between son and support and increase membership, he can be desirable to treat the surface of the wires in depending on the coating chosen.

Different geometries are proposed for a component according to the invention.

So for example, the wires can be wrapped around an elastic soul in the manner of a strand and secured to it, for example by gluing. During the elongation of the soul, the threads give the feeling of growing up also because of increase of the winding pitch. This geometry allows a very important elongation according to the diameter of the soul and the pitch of the winding for the son. The invention also relates to a method for realize this component, with rolling of the material wired around an elastic and solidarization soul.

Another geometry of a component according to the invention relates to a plate-shaped support on which the wires are arranged according to a geometry plane. Advantageously, the wires do not touch each other to avoid shearing. The geometry of the wires is preferably in the form of undulations whose the amplitude and the pitch depend on the elongation desired. Preferably, the geometry is regular all along the support in order to get properties controlled elongation. To maintain the geometry son at rest as predetermined, it is preferable to have a layer of elastic material, for example similar to the medium, above the assembly formed by the support and the wiring.

In another aspect, the invention a component of this second type, that is to say flat, to inside which the wire elements are arranged in the form of helical windings. This allows a longer lengthening.

The invention also relates to a method to realize this second type of component, that is to say including setting up wired elements according to a predefined geometry on a plane substrate, and the joining of the wire elements with a support elastic.

BRIEF DESCRIPTION OF THE DRAWINGS

La figure 1 montre les différents éléments et les paramètres utiles à la compréhension de l'invention.

La figure 2 représente un premier mode de réalisation d'un composant selon l'invention.

Les figures 3a, 3b et 3c illustrent trois configurations possibles pour le premier mode de réalisation.

Les figures 4a et 4b représentent deux configurations d'un deuxième mode de réalisation d'un composant selon l'invention.

La figure 5 représente un troisième mode de réalisation d'un composant selon l'invention, la figure 5a selon l'axe AA, la figure 5b selon l'axe BB.

Other characteristics and advantages of the invention will emerge more clearly on reading the description and with reference to the appended drawings, in which:

Figure 1 shows the various elements and parameters useful for understanding the invention.

FIG. 2 represents a first embodiment of a component according to the invention.

Figures 3a, 3b and 3c illustrate three possible configurations for the first embodiment.

Figures 4a and 4b show two configurations of a second embodiment of a component according to the invention.

FIG. 5 represents a third embodiment of a component according to the invention, FIG. 5a along the AA axis, and FIG. 5b along the BB axis.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

The invention relates to connection components comprising, as illustrated in Figure 1, an elastic support 2 and yarns 4 of lesser elasticity, the term "wire" being taken in its broad sense, namely a "long strand slim ". The threads have a first length l ₁ . By "connection components", and as it will be clearer later, it means both individually usable entities as well as parts of larger devices. In particular, the components comprise an elastic support 2: this support 2 of the component may also be only part of a larger support used in a device including the connector according to the invention.

The support 2 has at rest a second length l ₂ . During the use of the device including the support 2, bending the device, by vibration, or by any other mechanical action, the support 2 will see its length change, especially between l ₂ and a third maximum length l ₃ . The length l ₁ of the wires is chosen so that this movement of the support is possible, and therefore normally l ₁ ≥ l ₃ .

The invention is based on the fact that, contrary to the current approach of the skilled person, the son are integrated, associated, that is to say, secured to the support, so that no displacement occurs between the surface of the wire and the surface of the support which is adjacent to it during the elastic deformation of the support. Indeed, in view of the difference in nature between the polymer of a sheath and the electrical conductors, it has so far been considered either to alter or choose the nature of one of the elements to give each an elastic behavior similar (conductive rubber, wire embedded in a preformed flexible sheath), or to dissociate completely to allow a relative movement of one relative to the other (floating wire in a wide sheath). In the context of the invention, the conductors deform identically to the medium in which they are, but the son themselves keep a constant length and do not change impedance, or create extra thicknesses or loops absorption of length. The connection between wire 4 and support 2 is continuous, that is to say along the second length l ₂ .

In the context of the invention, the son used may be all commercially available son, or son made on demand. For the support, the choice of the material can be made in the same way among the known or specially developed materials, and depends mainly on the range of elasticity and the desired resistance: one can for example choose a weak material but capable of occasionally lengthen strongly (see rubber elastics), or prefer a very strong material capable of withstanding many deformation cycles, whose elasticity is limited to reduced elongation. In fact, by taking the parameters of FIG. 1, an elastic material is chosen between the lengths l ₂ and l ₃ , l ₂ being the length at rest, that is to say in the absence of tensile stress. It is desirable that the material of the support is isotropic in order to maintain uniform behavior irrespective of the direction of deformation, in particular over the entire length. Moreover, it is preferable that it can be molded to facilitate manufacture, and without hysteresis. For example, it is possible to take a polyurethane, a rubber, a neoprene, silicone.

Depending on the context in which the device will be used, a Shore hardness higher or lower will be chosen. For example, in a subject environment to significant forces and requiring low elongations (such as 1%), one can choose a material with a Shore hardness of about 40; in a less disturbed environment, subject to weaker, and requiring longer elongations important (like the joints of the human body), for example 100%, we can choose a material of Shore hardness of 5 to 10.

FIG. 2 represents a first possible embodiment, also called "stranded" configuration 10. According to this embodiment, a central core 12 is made of an elastic material chosen according to the criteria detailed above, the size (length and diameter of the core) also depends on the use that will be made of the component 10. Similarly, depending on the use, we choose the son 14 necessary (nature, number, length l ₁ at least equal to the maximum length l ₃ component 10). For example, it is possible to choose shielded and / or commercialized electrical wires, in particular coaxial wires.

Then, manually, by a device classic for stranding wires and / or ropes and / or cables, or by any other technique known to man of the craft, the son 14 are wound around the soul 12. The diameter and pitch of the turns of the strand will depend on the elongation that we want to compensate, but also the diameter of the soul. To ensure a the most reproducible behavior possible it is desirable that the windings be regular all along the soul 12.

Different configurations are possible: it is possible to wind the wires 14 independently from each other, so as to obtain windings nested (Figure 3a). The wires 12 can be themselves as an assembly or cables 16: the FIG. 3b thus shows a winding of cables 16 comprising three electric wires. In this case, it is desirable that the diameter of the cable 16 remains very less than the pitch of the winding. It is also possible to secure, for example by gluing, the different wires 14 before winding, preferably according to a planar configuration 18 (in the example, of three son), and to wind this flat set 18 on the soul 12 (Figure 3c). This configuration has the advantage of keep a small diameter, while minimizing risks of relative movement.

The winding is accompanied or followed by a bonding the wires 14 on the core 12 so as to be there solidariser and to avoid any displacement relative to their points of contact. Preferably, the glue is same material as the soul 12; it can be liquid also, for example for polyurethane. It is also possible to make a molding for ensure this solidarity. To accentuate again accession, it may be proceeded to a treatment of the surface of the wires 14, for example surrounding Teflon® coaxial shielded wires for integration into polyurethane.

Preferably, the ends 20 of the wires 14 are left free. To lengthen the device, one "pulls" on the soul 12, at one of its ends 22 or both. As the wires 14 are joined to the soul 12, a torsion of the soul accompanies its lengthening, and the visible length of the wires increases in parallel, following the increase of the pitch of their winding: it There is a mechanical decoupling between the efforts made by the soul 12 and the yarns 14. The central core 12 thus absorbs all the traction, and the wires 14 do not suffer no stress. Moreover, the absence of relative movement between core 12 and wire 14 allows a long life to component 10, dependent only limits to the elasticity of the material chosen for the core 12, without alteration due to shear caused by the movements of the yarns 14, along the interface between wires 14 and support 12.

To secure component 10, it is possible to coat, for example by molding, the strand initial by an elastic material. Preferably, the modulus of elasticity of the coating 24 is greater than that of the central core 12: this makes it possible to ensure the absence of stress on the conducting wires 14, and does not alter the elongation properties of the strand 10.

Although theoretically possible, the strand configuration 10 finds practical limits for a large number of threads, for example a dozen: indeed, the diameter of the whole becomes then important, and integrating the component into a device for use can be problematic.

The component according to the invention can be manufactured in another configuration, called configuration "in waves" 30, presented for example in FIGS. 4: in this embodiment, the son 32 are arranged on a plane, and secured to a support 34 flat. The thickness is therefore reduced.

In the same way as before, the length of the wires, their number, the material of the support, its dimensions depend on the desired elongation and of use - in particular, in this case, it is better to take for support 34 a material the closest possible to the product in which the component 30 will be used or even to manufacture the component 30 in and with the final device.

The wires 32 are arranged side by side on a substrate to form a flat conductor assembly. The geometry depends on the desired elongation and the difference in length between support 34 and son 32 (between l ₂ and l ₁ ): modeling to obtain the wave parameters is immediate. It is preferred that the son 32 do not touch, so as to avoid any shear between two son during stretching; it is therefore desirable for each wire to form a path parallel to that of its neighbor.

Two main configurations are detailed for this embodiment: according to the size of the "waves", that is to say, especially their amplitude, each thread "intertwines" into another ("Web" 36 of FIG. 4a) where the wires form "Undulating rails" 38 separated (Figure 4b). Both configurations can be mingled within a single device 30, with for example a sheet 36 of six framed son of 38 ripples on each side. The choice of geometry depends in particular on the drivers (length, nature) and the process of chosen embodiment to make the drawing of waves: thus, for a tablecloth 36, it can be considered to secure the son 32 on a plane as for the strand 10 of Figure 3c and then proceed positioning according to the drawing. To realize the low amplitude ripples 38 of FIG. 4b, a possibilities can be the passage of the wire 32 along a toothed gear.

In order to ensure regular behavior on the entire length of component 30 it is desirable that the corrugations 36, 38 have an amplitude and a constant periodicity throughout the support 34.

After all 32 threads has been placed on the surface of the substrate, the wires are embedded in an elastic material, constituting support 34, preferably by molding and / or injection. The same precautions and possibilities as for the strand 10 apply.

It is possible that the substrate on which the wires were arranged either of the same nature as the elastic material, that is to say the support 34: then obtained during molding a support 34 comprising the initial substrate and the added product, within which conductors 32 are integrated on a plane. In this case, before injection of the material that will constitute the upper part of the support 34, it can be desirable to stick the wires on the substrate, which constitutes the lower part of the support 34; the glue can be polyurethane, rubber, liquid or pasty.

To further reduce the final thickness, is possible to carry out a geometry report, the substrate serving only to position the front wires 32 they are molded in an elastic material forming the support 34. In this case, the wires 32 of the component 30 are practically on its surface. As in the case of the strand 10, it is possible in this case also to proceed to a coating.

Unlike the embodiment in strand 10, it is not, in this second mode of realization, not possible to separate the support 34 wires 32 during elongation efforts: "pull" on the support 34 amounts to pulling on the threads 32. allow a recovery of effort that avoids any stress causing shear on the wires 32 leading to breakage, it is desirable that the support 34 is extended at one of its ends to less. For example, the extension 40 can be molded at the same time as the support 34 and the ends of the son 32 can be joined, for example for be connected to a plate 42 or a sensor. It is possible to develop waves in this extension to compensate for the forces due to traction.

Figure 5 shows a third mode of accomplishment 50 combining aspects of both precedents: instead of being laid flat on a substrate, the wires 52 are in the form of helices or of windings. The arrangement of the wires 52 on the substrate can be done with single wires, which are coiled and retain their geometry, or wires can be rolled up on a soul as in the first embodiment. In this case, it is preferable that the soul is of the same nature as the material used then for support 54, so that during molding, the two elements blend, interlock one in the other, which increases the membership son 52 to support 54. We then obtain a intermediate structure 50 which may comprise numerous son 52 determining the width of the support 54, thickness between that of the strand 10 and the wave configuration 30.

Whatever the embodiment chosen, it is clear that the membership must be at the points of contact between the support 12, 34, 54 and the wires 14, 32, 52. Depending on the desired elongation and the number of cycles to which it is intended to submit the component 10, 30, 50 (repeated vibrations of low amplitude are actually more harmful in case of shear that extreme elongations but occasional), it may be desirable to remove any gaseous residue within the material, especially polymeric, component support and glue possible, especially to avoid any bubbles of air around a wire: the molding step and / or bonding the wires 14, 32, 52 continuously on the core 12 and / or the support 34, 54 can therefore be associated with degassing known to those skilled in the art.

The applications of such a connection 10, 30, 50 are numerous. In particular, avionics and more generally in the field of transport (so many people and conveyors on industrial production line), the component according to the invention makes it possible to ensure an elastic deformation some ducts containing electrical wires while avoiding the shear problems inherent in repeated vibrations which, with known connectors, cause deterioration due to the movement relative between wire and surrounding support.

In the same way, the component can be used in the medical field, for example in joint prostheses. It is here possible to stick a component according to the invention at the level of the joint concerned, for example to connect a sensor to means of activation or control of movement. It is also possible to integrate directly the component in the prosthesis or the appliance medical, for example by choosing silicone as support if integration into a silicone probe is considered.

Although the description and drawings above relate to electrical wires embedded in an elastic connection, the invention is not limited this embodiment but groups the elements departing from the scope of the claims.

In particular, the electric wires can be replaced, for all or only some of them, by any form element elongated similar to a wire, inextensible or at least not expandable enough for the use that is done, which one wants to use as part of a binding on an elastically deformable support.

One of the examples is the use of optical fibers, singlemode or multimode: in medical applications (in endoscopy for example) as in industrial applications (monitoring hydraulic circuits, for example) or underwater applications (cameras for example) it may be necessary to have parts likely to undergo significant deformations. The component according to the invention makes it possible to replace the existing joints. Especially, when using repeated, the integration of fibers into a support for a component according to the invention makes it possible to reduce diameter while increasing the service life due to the absence of shear forces between sheath protection and optical fibers.

Because of its compactness and resistance during the deformation cycles, the component according to the invention can also be used in the field of clothing: it becomes possible to integrate clothing, and in particular to the footwear or the combination diving, sensors at remote locations means controlling them, or current accessories on a certain length.

Claims (23)

A connection component (10, 30, 50) comprising at least one wire (14, 32, 52) having a first length (1 ₁ ) and a support (12, 34, 54) having a second length (1 ₂ ), the second length being less than the first, the support being made of a material which is elastic between the second length at rest and a third length (l ₃ ), characterized in that the wire (14, 32, 52) is continuously secured to the support (12, 34, 54) so that, during the elastic deformation of the support between the second length (l ₂ ) and the smallest of the first (l ₁ ) and the third length (l ₃ ), the wire (14 , 32, 52) undergoes no relative movement relative to the support (12, 34, 54) at the interface between wire and support. Component according to claim 1 wherein the support is in the form of an elongate soul (12). Component according to claim 2 wherein each wire (14) forms a coil around of the soul (12). Component according to claim 3 comprising several wires (14) joined together, the assembly (18) of the wires (14) forming a winding not non-zero around the soul (12). Component according to one of the Claims 2 to 4 comprising a coating (24) elastic material around the core (12) and wires (14). Component according to claim 1 comprising a plane defined by the wires (32) on the length of the support (34). Component according to claim 6 in which the plane is located inside the support (34) of elastic material. Component according to one of the Claims 6 to 7 comprising a plurality of wires (32) such that none of the wires are in contact with a other. Component according to claim 8 wherein the wires (32) form paths parallel. Component according to one of the Claims 6 to 9 in which each wire (32) is in the form of undulations (34, 36) in the plane on at least part of the second length of the support (34). Component according to claim 10 wherein the elongations (34, 36) extend over the entire length of the support (34). Component according to one of the Claims 10 to 11 wherein the corrugations have a regular amplitude and frequency. Component according to claim 1 comprising at least two wires (52), each wire (52) being in the form of a helical winding, the windings being located entirely inside of the support (54). Component according to one of the Claims 6 to 13 further comprising a extension (40) of the support (34, 54) to be used to connect the component and / or exercise traction. Component according to one of the Claims 1 to 14 in which the yarns (14, 32, 52) are inextensible. Component according to claim 15 wherein the wires are selected from coaxial or optical fibers. Component according to one of the Claims 1 to 16, in which the support (12, 34, 54) is made of polyurethane or silicone or rubber. Component according to one of the claims 1 to 17 wherein the support is isotropic. Elastic connector including a component (10, 30, 50) according to one of claims 1 at 18 in which at least one wire is a conductor electric, each driver having extensions (20) outside the support (12, 34, 54) on one side to less so as to allow its electrical connection. Method of manufacturing a component elastic connection including the positioning of son according to a determined geometry, and the continuous joining of the yarns with a material elastic band as a support so that there is no have no displacement between the surface of the wires and the surface of the support adjacent to the wires during a deformation of the support. Process according to claim 20 comprising shaping an elongate core into elastic material, the winding of elastic threads inferior to the support around the soul, and the solidarization of the threads to the soul. Process according to claim 20 comprising placing wires in a geometry predetermined in a plane, then the joining by molding of the geometry in an elastic support. Method according to one of the claims 20 to 22 including treatment of the surface of the wires before joining.

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