JP7507489B2 - Elastic Cable - Google Patents

Description

This invention relates to an expansion cable that can expand, contract, bend and twist.

A conventional example of an expandable cable is the curl cord described in Patent Document 1. This curl cord is made by covering the entire outer circumference of a conductor made of multiple twisted thin metal wires with an insulating coating to form an insulated wire, which is curled into a spiral shape and then heated and cooled to remove distortion. The spiral shape can be reversed to make it easier to maintain the spiral shape, allowing it to expand, contract, bend, and twist.

Now, elastic cables are sometimes used to electrically connect objects whose relative positions or orientations change, for example, between electrode pads attached to the skin of a subject, such as a patient, to detect biosignals such as electrocardiogram signals, and a measuring device, such as a Holter monitor, held by the subject.

JP 2017-182950 A

However, in the above cases, if a curl cord is used as an expandable cable, because the curl cord has a helical shape and is thick overall, there are parts that are separated from the subject's body, and so there is the problem that it can be significantly deformed by the subject's body movements or get caught on the subject's clothing, etc., causing it to become detached from the connection targets such as electrode pads and measuring equipment, or to shift the connection targets from their original positions or be peeled off. This problem is particularly serious when it is desired to increase the distance between connection targets, for example to several tens of centimeters or more, in order to extend the spacing between electrode pads or increase the number of them.

However, it was discovered that trying to solve this problem by fastening the curled cord to the subject's body with a belt or similar would result in a new problem: the curled cord would be bulky, making it difficult for the subject to move.

The present invention advantageously solves the problems of the prior art described above, and the elastic cable of the present invention is:
A single or multiple conductors arranged side by side each having a flat shape that extends so as to be capable of expanding, contracting, bending and twisting;
a flat insulating coating that entirely covers the one or more conductors arranged side by side and extends along the conductors, and that is elastically capable of stretching, bending, and twisting;
Equipped with
each of said one or more lateral conductors comprises a bare, stranded or braided wire of a conductive metal;
The flat conductor extending in an elastic, flexible and torsional manner is a cylindrical or rectangular coiled conductor that is pressed flat in the diametrical direction of the coil,
The flat insulating coating, which entirely covers the single conductor or multiple lateral aligned conductors and extends along the conductors, and is capable of elastically expanding, contracting, bending and twisting, is characterized by having an adhesive layer on at least the back surface .

The expandable cable of this invention is equipped with one or more lateral aligned flat conductors that extend and are capable of expanding, bending and twisting, and a flat insulating coating that entirely covers the conductor and extends along the conductor and is capable of elastically expanding, bending and twisting, so that the expandable cable as a whole has a sheet shape that is elastically expandable, bending and twisting.

Therefore, according to the expandable cable of the present invention, even when used for electrical connection between connection objects whose relative positions or orientations change two-dimensionally on the same plane or three-dimensionally in space, for example, between an electrode pad attached to the skin of a subject that detects biosignals such as electrocardiogram signals and a measuring device such as a Holter electrocardiograph carried by the subject, the sheet-like expandable cable can be fixed with a belt, an adhesive layer, or the like and extend along the subject's skin, so that even if the subject moves, the cable elastically expands and contracts, bends and/or twists in response to the body movement to maintain its position along the subject's skin, and therefore the connection between the connection objects can be maintained without causing problems such as the connection object becoming detached from the connection object, the connection object itself being shifted from its original position or peeled off, or the subject's body movement being hindered, and this is particularly advantageous when it is desired to increase the distance between the connection objects to, for example, several tens of centimeters or more in order to extend the spacing between electrode pads or increase the number of electrode pads arranged. Furthermore, by using the adhesive layer, the back surface of the insulating coating of the expandable cable can be fixed to the subject's skin, etc., so that the expandable cable can be left extending along the subject's skin, etc., without being fixed with an attachment such as a belt.

In the expandable cable of the present invention, each of the single conductor or multiple conductors arranged side by side is made of a bare single wire , a twisted wire, or a braided wire made of a conductive metal such as copper, and the multiple conductors arranged side by side may be a combination of multiple types of these conductors arranged in an array.

Furthermore, in the expandable cable of the present invention, the flat-shaped conductor which extends and is capable of expanding, contracting, flexing, and twisting is a cylindrical or square-tube coiled conductor that has been pressed flat in the diameter direction of the coil, and the conductor is made of bare single wire, twisted wire or braided wire of a conductive metal as described above , so that the wires overlap and come into contact with each other at least every turn of the coil and electricity flows at the contact position, and therefore the electrical resistance over the entire length of the conductor can be made as low as when the conductor is straight for the length of the coil.

In addition , the flat insulating coating which entirely covers and extends along the at least one conductor and is elastically stretchable, flexible and twistable may be formed by overlapping two films or a folded portion of a single film in the width direction so as to entirely cover and extend along one or a plurality of horizontally arranged conductors, and then welding the overlapping films together with heat or a solvent, or bonding them with an adhesive, to form a substantially flat shape; alternatively, the conductor may be insert-molded by positioning one or a plurality of horizontally arranged conductors in a mold cavity which extends in a substantially flat shape, and injecting molten coating material made of an insulating resin which is elastically stretchable, flexible and twistable around the conductor in the mold cavity and hardening it.

Furthermore, the flat insulating coating that entirely covers the one or more conductors and extends along the conductors and is capable of elastically expanding, contracting, bending, and twisting may have fixing portions such as screw holes on both sides of the portion of the flat shape that covers the conductors for fixing an end or an intermediate portion of the expandable cable to an electrode pad, a measuring instrument, or the like with a screw .

At least one end of the expandable cable of the present invention may have a connection portion for detachably and electrically connecting the single conductor or multiple conductors arranged side by side to an electrode pad, a measuring device, etc.

1 is a perspective view showing one embodiment of an expandable cable of the present invention with a portion of an insulating coating cut away. FIG. 1A is an oblique view showing the state in which the expandable cable of the above embodiment is bent and deformed in the direction perpendicular to the plane (Z-axis direction), FIG. 1B is an oblique view showing the state in which the expandable cable of the above embodiment is bent and deformed (laterally bent) in the in-plane direction (Y-axis direction), and FIG. 1C is an oblique view showing the state in which the expandable cable of the above embodiment is torsionally deformed along its extension direction axis (X-axis). 4A and 4B are partially cutaway perspective views showing examples of the configuration of a connection portion at the end of the expansion cable of the embodiment. 1A to 1D are perspective views showing conductors in an expansion cable according to a first embodiment of the present invention.

The following describes in detail the embodiments of the present invention with reference to the drawings. FIG. 1 is a perspective view of one embodiment of the expandable cable of the present invention with a portion of the insulating coating cut away, FIG. 2(a) is a perspective view of the expandable cable of the embodiment in a state where it is flexed in a direction perpendicular to the plane (Z-axis direction), FIG. 2(b) is a perspective view of the expandable cable of the embodiment in a state where it is flexed (bent laterally) in an in-plane direction (Y-axis direction), and FIG. 2(c) is a perspective view of the expandable cable of the embodiment in a state where it is torsionally deformed along its extension axis (X-axis). In the figures, the reference numeral 1 denotes the expandable cable.

As shown in FIG. 1, the expandable cable 1 of this embodiment comprises two substantially flat conductors 2 arranged side by side, which extend so as to be capable of expanding, contracting, bending, and twisting, and a flat insulating coating 3 which entirely covers the two conductors 2 arranged side by side and extends along the conductors 2 and is capable of elastically expanding, contracting, bending, and twisting. Note that, although there are two conductors 2 in this embodiment, the number of conductors 2 may be one or three or more.

Here, each of the two side-by-side conductors 2 is sufficient as long as it can transmit a signal, and in this embodiment, it is made of a bare single wire of a conductive metal such as copper. Also, the substantially flat shape of the conductor 2 that extends so as to be capable of expanding, contracting, bending and twisting is formed in this embodiment by pushing down the conductor 2 wound in a cylindrical coil in the diameter direction of the coil.

When the conductor 2 is made of a bare single wire of the conductive metal described above or a bare twisted or braided wire described below, by pressing down the coil-shaped conductor 2 to form it substantially flat, the conductor 2 can be extended so that it can expand, contract, bend, and twist. In addition, the wires can be overlapped and contacted with each other at least every turn of the coil, allowing electricity to flow at the contact position, so that the electrical resistance of the conductor 2 can be made lower than that of a cylindrical coil that is not formed flat.

Furthermore, the flat insulating coating 3 that entirely covers the two conductors 2 and extends along the conductors 2 and is elastically stretchable, flexible, and twistable is, in this embodiment, made of two films 3a, 3b made of insulating resin that are elastically stretchable, flexible, and twistable, and is layered so as to entirely cover the two conductors 2 arranged side by side and extend along the conductors 2, and the layered films 3a, 3b are fused together or to the conductors 2 by heating or a solvent, or are bonded with an adhesive, to form a substantially flat shape.

Instead of the two films 3a and 3b, the insulating coating 3 may be formed into a substantially flat shape by folding a single film made of an insulating resin that is elastically expandable, flexible, and torsionally deformable in half in the width direction, overlapping the folded portion so as to entirely cover one or a number of conductors 2 arranged side by side and extend along the conductors 2, and welding the folded portions of the overlapping film with heat or a solvent, or by bonding them with an adhesive.

Alternatively, the insulating coating 3 may be formed by insert-molding the conductor 2 by positioning one or multiple conductors 2 arranged side by side in a mold cavity (not shown) that extends in a substantially flat shape, injecting a molten coating material made of an insulating resin that can elastically expand, contract, bend, and twist around the conductor 2 in the mold cavity, and then hardening the material.

The expandable cable 1 of this embodiment formed in this way has a sheet-like shape that can elastically expand, contract, bend, and twist as a whole, so in addition to being able to elastically expand and contract in the linearly extending state shown in FIG. 1, it can also be elastically bent from the linearly extending state shown in FIG. 1 in a direction perpendicular to the plane (the Z-axis direction, which is perpendicular to the plane of the flat shape) as shown in FIG. 2(a), in an in-plane direction (the Y-axis direction, which is parallel to the plane of the flat shape) as shown in FIG. 2(b), or twisted along its extension axis (the X-axis) as shown in FIG. 2(c).

Furthermore, as shown in FIG. 1, the expandable cable 1 of this embodiment has two terminals 4 made of conductive metal at at least one end 1a, which are electrically connected to the ends of the two conductors 2 by soldering or the like, and these terminals 4 can be formed on the film 3b by electroplating, for example, like printed wiring.

In addition, the expandable cable 1 of this embodiment has an adhesive layer 5 on one side of its insulating coating 3 as shown in FIG. 1, except for the end 1a having the terminal 4, which is the entire back surface in FIG. 1, and this adhesive layer 5 can be provided by applying an adhesive to one side of the insulating coating 3 or by attaching a double-sided adhesive tape.

Therefore, according to the expandable cable 1 of this embodiment, even when used for electrical connection between connection objects whose relative positions or orientations change two-dimensionally within the same plane or three-dimensionally within space, for example, between electrode pads attached to the skin of a subject that detects biosignals such as electrocardiogram signals and a measuring device such as a Holter electrocardiograph carried by the subject, the sheet-like expandable cable 1 can be fixed to the skin of the subject with the adhesive layer 5 and extend along the skin, so that even if the subject moves, it elastically expands and contracts, bends and/or twists in response to the body movement to maintain its position along the skin of the subject. Therefore, the electrical connection between the connection objects can be maintained for a long time without causing problems such as coming off the connection object, shifting the connection object itself from its original position or peeling it off, or interfering with the body movement of the subject. As a result, the cable can be suitably used, for example, for a Holter electrocardiograph that can continuously measure and record electrocardiogram signals for several days or more while being carried by the subject. In particular, when extending the spacing between electrode pads or increasing the number of electrode pads to measure electrocardiogram signals in more detail, the distance between the electrode pads or between the electrode pads and the Holter electrocardiograph can be increased to, for example, several tens of centimeters or more without any inconvenience.

The adhesive layer 5 can also be provided on the front surface of the insulating coating 3 if necessary. By using the adhesive layer 5, electrical elements connected to the conductor 2, such as strain gauges that detect the amount of deformation of the expandable cable 1, thermocouples that detect the temperature of the skin at the installation location, and piezoelectric elements that detect the pressure applied to the expandable cable 1 at the installation location, can be provided at any position along the longitudinal direction of the expandable cable 1.

Figures 3(a) and (b) are partially cutaway perspective views showing examples of the configuration of the connection part of the end 1a of the expandable cable 1 of the above embodiment. In the example shown in Figure 3(a), a relay plug 6 is used as the connection part. This relay plug 6 has a slit at one end of a plug body 6a made of insulating resin through which the end 1a of the expandable cable 1 can be inserted and removed, and the base parts of two metal fittings 6b made of a relatively thick metal plate insert-molded into the plug body 6a and molded into a leaf spring shape are exposed in the slit, and the tips of these metal fittings 6b protrude from the other end of the plug body 6a.

When the end 1a of the retractable cable 1 is inserted into the slit in the plug body 6a of this relay plug 6, the leaf spring-shaped bases of the two metal fittings 6b are pressed against the two terminals 4 of the end 1a, allowing electricity to flow. By inserting the high-strength tips of the two metal fittings 6b, which are made of relatively thick metal plates, into the corresponding sockets of the device to be connected, the two conductors 2 of the retractable cable 1 can be securely electrically connected to the device to be connected.

In the example shown in FIG. 3(b), the connection is formed by fastening two terminals 4 at the end 1a of the expandable cable 1 to two nuts (not shown) embedded in an insulating resin substrate 7a that is part of the device to be connected 7 with small screws 8 that penetrate into screw holes provided in the nuts. By using these nuts and small screws 8, the two terminals 4 can be securely electrically connected to the two wires 7b formed on the surface of the insulating resin substrate 7a.

4(a) to 4(d) are perspective views showing the conductor 2 in an expandable cable 1 according to a reference embodiment of the present invention, and in the reference embodiment of Fig. 4(a), the conductor 2 is made of a bare conductive metal single wire, which is covered by two films 3a and 3b of an insulating coating 3 in a state capable of stretching, bending and torsional deformation, for example in a flat meandering state (not shown). Also, in the reference embodiment of Fig. 4(c), the conductor 2 is made of a conductive metal single wire 2a insulated and coated with a resin coating 2b, which is covered by two films 3a and 3b of an insulating coating 3 in a state capable of stretching, bending and torsional deformation, for example in a flat meandering state (not shown).

4(b), the conductor 2 is made of a bare stranded wire 2c of conductive metal, and is covered with two films 3a and 3b of the insulating coating 3 in a state capable of stretching, bending and twisting deformation, for example in a flat meandering state (not shown). Also, in the reference embodiment of FIG. 4(d), the conductor 2 is made of a stranded wire 2d of conductive metal insulated and coated with a resin coating 2e, and is covered with two films 3a and 3b of the insulating coating 3 in a state capable of stretching, bending and twisting deformation, for example in a flat meandering state (not shown).

The expandable cables 1 of the reference embodiments shown in Figs. 4(a) to 4(d) can also achieve the same effects as the previous embodiments, except for the effects achieved by the flattened coil-shaped conductor 2.

Although the present invention has been described above based on the illustrated embodiment, it is not limited to the above embodiment and can be modified as appropriate within the scope of the claims .

The elastic cable of this invention can be used not only for electrical connection between an electrocardiograph carried by the subject and electrocardiogram electrode pads attached to the subject's skin, but also for electrical connection between a work-assist robot or electric prosthesis worn by the subject and electromyogram electrode pads attached to the subject's skin, making it possible to reliably control the work-assist robot or electric prosthesis using the subject's electromyogram signals.

Thus, according to the elastic cable of this invention, even when used for electrical connection between connection objects whose relative positions or orientations change two-dimensionally on the same plane or three-dimensionally in space, for example, between electrode pads attached to the skin of a subject that detects biosignals such as electrocardiogram signals and a measuring device such as a Holter electrocardiograph carried by the subject, the sheet-like elastic cable can be fixed with a belt or adhesive layer and extend along the subject's skin, so that even if the subject moves, it elastically expands and contracts, bends and/or twists in response to the body movement to maintain its position along the subject's skin, and therefore the connection between the connection objects can be maintained without causing problems such as coming off the connection object, shifting the connection object itself from its original position or peeling it off, or interfering with the subject's body movement, and this is particularly advantageous when it is desired to increase the distance between the connection objects to, for example, several tens of centimeters or more in order to extend the spacing between the electrode pads or increase the number of electrode pads.

REFERENCE SIGNS LIST 1 Expandable cable 1a End 2 Conductor 2a Solid wire 2b Resin coating 2c, 2d Stranded wire 2e Resin coating 3 Insulating coating 3a, 3b Film 4 Terminal 5 Adhesive layer 6 Relay plug 6a Plug body 6b Metal fitting 7 Device to be connected 7a Insulating resin board 7b Wiring 8 Machine screw

Claims (4)

A single or multiple conductors arranged side by side each having a flat shape that extends so as to be capable of expanding, contracting, bending and twisting;
a flat insulating coating that entirely covers the one or more conductors arranged side by side and extends along the conductors, and that is elastically capable of stretching, bending, and twisting;
Equipped with
each of said one or more lateral conductors comprises a bare, stranded or braided wire of a conductive metal;
The flat conductor extending to be capable of expanding, contracting, bending and twisting is a cylindrical or rectangular coiled conductor pressed flat in a diametrical direction of the coil,
An expandable cable, characterized in that a flat insulating coating that completely covers the single conductor or multiple horizontally arranged conductors and extends along the conductors, and that is elastically capable of expanding, contracting, bending, and twisting, has an adhesive layer on at least the back surface . The elastically stretchable, flexible and twistable flat insulating coating that entirely covers the single or horizontally arranged conductors and extends along the conductors is made of two films or a folded portion of a single film made of an elastically stretchable, flexible and twistable insulating resin that is overlapped so as to entirely cover the single or horizontally arranged conductors and extend along the conductors, and the overlapped films are welded or glued together to form a flat coating. The elastically stretchable, flexible and twistable flat insulating coating that entirely covers the single or horizontally arranged conductors and extends along the conductors is made of two films or a folded portion of a single film that is folded in two in the width direction of the film that is overlapped so as to entirely cover the single or horizontally arranged conductors and extend along the conductors, and the overlapped films are welded or glued together to form a flat coating. The elastic cable according to claim 1, characterized in that the flat insulating coating that entirely covers the single or multiple horizontally arranged conductors and extends along the conductors and is capable of elastically expanding, contracting, bending, and twisting is formed by insert molding the single or multiple horizontally arranged conductors into a coating material made of insulating resin that is capable of elastically expanding, contracting, bending, and twisting. The elastic cable according to claim 1, characterized in that at least one end of the elastic cable has a connection part for detachably and electrically connecting the single conductor or the multiple conductors arranged side by side to a connection target.

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