FR2792657A1 - METHOD AND DEVICE FOR MANUFACTURING A CONTAINER BAND, CORRESPONDING BAND AND ITS USE - Google Patents

Abstract

The present invention relates to a method of manufacturing an elastic compression band (1) of limited extensibility in the longitudinal direction, consisting in combining longitudinally, in a fabric constituting said band, elastic threads and inextensible threads, said inextensible threads being totally stretched when the elongation of said fabric is maximum. The product according to the invention is characterized in that: a) the elastic fabric formed by the elastic threads is an elastic pre-existing fabric, b) said inextensible threads are inserted into said pre-existing fabric by means of a sewing machine (2) forming points (4) arranged parallel to each other in the longitudinal direction of the strip (1), said pre-existing fabric being subjected during the stitching to a predetermined relative elongation (DELTAL / L). Applicable to the manufacture of tapes mainly used in phlebology, angiology, orthopedics and sports use.

Description

-1-

  METHOD AND DEVICE FOR MANUFACTURING A WEB

  CONTENT, CORRESPONDING STRIP AND USE THEREOF.

  The present invention relates to elastic fabrics in the form of more or less wide bands used mainly in

  phlebology, angiology, orthopedics or sports use.

  TECHNOLOGICAL BACKGROUND OF THE INVENTION

  Articles of elastic fabric, such as bands, knee pads, ankles, elbow pads and other orthoses, or even such as belts, are commonly used, wrapped around a limb or around the

  body, for purposes of restraint and / or support.

  The generally known bands are either elastic bands incorporating a chain of elastic threads, or stretch bands with limited elasticity, without any real restoring force and incorporating

  warp of textured yarns or rigid, overstitched yarns.

  The first type of bands and their manufacturing processes can be illustrated by US Pat. No. 5,014,403 issued to George Buese and published on May 14, 1991. An elastic fabric constituting a stage in the production of a band intended to serve as a support with a polymerizable resin, modern version of the classic plaster, for immobilization of a member in the event of a fracture for example, is obtained by knitting elastic threads under tension

with a fiberglass cloth.

  The strips of the second type can be illustrated by US Pat. No. 4,984. 566, published January 15, 1991 and granted to Takayuki Sekine. Synthetic fibers wound in a spiral on themselves or knitted in a zigzag pattern give the resulting fabric an elasticity greater than that of the elastic bands of the prior art, as precisely shown by the

tension / extension curves.

  However, in both cases, it is extremely difficult to materialize the position of the material which passes from the elastic state to

  a state of permanent deformation.

  The belt tension gradually increases to the elastic limit, as also shown in the published curves

  in US Patent 4,984,566, no warning sign announces this limit.

  -2- We therefore sought to evaluate a given elongation position using calibration principles, as implemented by the compression article described in patent application FR-2,544,982 filed by Etablissements Thuasne & Cie et la Société Thuasne-Paris, and published on November 2, 1984. In this realization, a geometric pattern, in this case the four vertices of a rectangle, is printed on the strip at rest. The transformation of the rectangle into a square makes it possible to locate

  visually the appropriate elongation.

  However, this improvement does not change how

  be it the tension / stretch curve of the fabric.

  However, there are therapeutic needs for compression bands whose elongation is limited, and which exert pressure

moderate below this limit.

  Patent US-3,332,416 published July 25, 1967 describes such a band. The inventors, L. Brickman et al., Proposed to manufacture a compression bandage which does not compress the body part too much

  treated, and cannot be extended beyond its limit during its installation.

  The proposed solution consisted in using a fabric comprising both elastic and inextensible threads. When the strip is at rest, the inextensible threads form loops in the fabric. The elongation of the fabric is limited by the inextensible threads which are fully stretched when the fabric is

  in a state of maximum elongation.

  The process consisting in limiting the elongation of an elastic thread by a rigid thread is well known, and used in several other fields of manufacturing. For example, patent application EP-0.216.122 filed by the company B.F. Goodrich, and published on April 1, 1987, shows how the extensibility of a belt can be controlled by providing

  coil of rigid wires inside the material constituting it.

  The implementation of the process is often complicated, and results in the need to manufacture a specifically designed fabric.

for this purpose.

  The patent application FR-2.509.169 filed by the Molinier S.A. company, and published on January 14, 1983, is characteristic of this approach. The compression band which is disclosed is executed on Rachel type needle knitting machines, and has a complex mesh structure. The strip is mainly characterized in that a combination of chains of inextensible meshed yarns and of elastic warped yarns not meshed but interlaced with the inextensible chains is produced longitudinally. The longitudinal extendable threads are woven stretched, so that after manufacture, the chains of inextensible threads are retracted and give the strip an embossed appearance, different from the appearance of conventional strips. It appears from the state of the art as described in the documents cited above that the person skilled in the art has clearly identified the characteristics of the ideal compression band that best meet the various therapeutic needs, but that he To date, there is no product on the market that is both easily manufactured and easy to install for the practitioner and

  easy for the patient to bear.

  GENERAL DESCRIPTION OF THE INVENTION

  The present invention therefore relates to elastic fabrics in the form of bands used mainly in phlebology, in

  angiology, orthopedics or sports.

  Its specific objects are (a) a method of manufacturing an elastic compression bandage of limited extensibility in the longitudinal direction, (b) the device for implementing the method, and (c) the

  corresponding strip and its use.

  Conventionally, the method consists in longitudinally combining, in a fabric constituting the strip, elastic threads and non-elastic threads, which non-elastic threads are completely

  stretched when the elongation of the tissue is maximum.

  Non-elastic threads can be either inextensible or textured, therefore not straight, but then not gifted

  of elasticity. However, in all the description which follows, and for a

  better understanding of the invention, the two forms of such threads not

  elastic bands will be united under the same term of "inextensible threads".

  According to the invention, the essential characteristic of the process is that: a) the elastic fabric formed by the elastic threads is a preexisting elastic fabric; b) the inextensible threads are inserted into the preexisting fabric by means of a sewing machine forming stitches arranged parallel to each other in the longitudinal direction of the strip, which preexisting fabric is subjected during stitching to elongation relative predetermined. An additional feature of the

  manufacturing according to the invention is that these stitches are of the "chain stitch" type.

  Very advantageously, the strip is manufactured continuously, the sewing machine being fed upstream with the elastic fabric at a linear speed lower than the linear speed of the receiving means downstream, the relative difference of these linear speeds being equal to the elongation

relative of the fabric.

  A device specially designed for implementing the method according to the invention comprises: a) a first train of traction cylinders, intended to supply the device with the elastic fabric, driven at a first speed

tangential adjustable.

  b) a sewing machine intended to form stitches

  with inextensible threads in the elastic fabric.

  c) a second train of traction cylinders, intended to receive the elastic fabric after stitching, driven by a second speed

tangential adjustable.

  The trains of cylinders are arranged in such a way that the relative difference between the first speed and the second speed is equal to

  the predetermined relative elongation of the tissue.

  In addition, the sewing machine has a program for forming chains arranged parallel to each other.

  others in the longitudinal direction of the strip.

  Advantageously, the first and second sets of cylinders are driven by stepping motors whose control pulses are synchronized with the insertion cycle of the needles of the

sewing machine.

  The compression band produced by the process and by means of the device according to the invention is characterized in that the slope of the curve representing the tension of the band as a function of its relative elongation increases suddenly for a value corresponding to said

  relative predetermined elongation and becomes practically infinite.

  An additional feature of the band is that the chains are placed in the elastic fabric along broken lines

  when the latter is in the rest position.

  -5- The compression band according to the invention constitutes a therapeutic indication for cases requiring both a flexible wrapping of the anatomical contours and a barrier effect

  controlling or preventing any deformation.

  It is preferably used in orthopedics, the barrier effect being comparable to a rigid support, in particular a plaster, and in phlebology, this effect resulting in a variation of the pressure exerted

  by the band promoting venous and lymphatic circulation.

BRIEF DESCRIPTION OF THE DRAWINGS

  Figures la and lb are respectively the tension / relative elongation curves of an elastic compression bandage

  conventional and an elastic compression band according to the invention.

  Figure 2 is a schematic view of the

manufacturing according to the invention.

  Figure 3a is a perspective view of a portion of the elastic compression bandage according to the invention, in a state of maximum elongation showing, on the surface thereof, the longitudinal chains of inextensible son perfectly aligned. Figure 3b is a side view showing the strip in its maximum elongation state and in

  its resting state, where the chains form broken lines.

  DESCRIPTION OF A PREFERRED FORM OF

THE INVENTION

  The references to Figures la and lb will serve to

  explain the general principle of the invention.

  The object of the process according to the invention is the modification of the tension / elongation relationship of a basic elastic fabric represented by FIG. 1a so as to obtain the curve of the type illustrated by FIG. 1b. Figure la shows that the tension (T) necessary to produce a given relative elongation (AL / L) increases progressively from the rest state (O) to tend towards a level (A) which marks the passage -6- to a state of permanent deformation, then increases sharply again

up to the breaking limit (B).

  In practice, exceeding the inflection point (A)

is difficult to appreciate.

  It is not the same for a fabric having the characteristics illustrated in Figure lb. The curve has an angular point (C) corresponding to a sudden increase in the slope, which becomes very large, practically infinite, up to the breaking limit (D). At this angular point (C) the tissue suddenly passes from the flexible state to the rigid state. The slope being significant, we understand that this change of state makes it possible to achieve a real barrier without initially generating considerable force,

  which makes the product fitted with this strip easy to install and easy to support.

  The method according to the invention ensures this transformation without appreciably modifying the appearance and the texture of the fabric.

  original, as the references to Figures 2 and 3 will be used to explain it.

  It consists in inserting into the fabric constituting the strip (1), by means of a sewing machine (2) of the "chain stitch" type, threads parallel to each other and arranged in the longitudinal direction of the strip ( 1). The needles (3) carry out a penetration movement and, via their looper, form the chains (4). They are the ones that will block and identify the position of maximum elongation (angular point (C) of the curve in Figure lb) obtained with the stretched strip (1). When the fabric comes into the rest position, without tension, the chains are positioned in the fabric

following a broken line.

  A determined difference (AL) between the extended position and the rest position of the strip is obtained by appropriate adjustment of the device.

  according to the invention, which will be described in conjunction with Figure 2.

  A first train (5) of traction cylinders (6) supplies the sewing machine (2) with elastic fabric, which is received after stitching by a second train (7) of cylinders (8). The two trains (5, 7), driven respectively by two adjustable tangential speeds V1 and V2, tension the elastic band (1). Their speed difference in percentage results in a relative elongation of the strip (1) of the same value. In other words, the elongation of the strip (1) is obtained by the speed differential between the

two trains (5, 7) of cylinders.

  An electronic servo controls the adjustment and control of the sewing machine (2). To synchronize the assembly, the stepping motors which control the roller trains (5, 7) receive their pulses from the motor shaft of the sewing machine (2). It is preferable for the reliability of the formation of the meshes (4) to wedge the advancement

  of the strip (1) on the needle insertion cycle (3).

  The elastic fabric thus modified provides service functions not available today on the market. By way of nonlimiting examples, mention may be made, in orthopedics, of straps used for "strapping" and, in

  phlebology, bands to facilitate venous or lymphatic return.

  In orthopedics or sports use, the use of this strap makes it possible to wrap the anatomical contours (ankle, knee, elbow, ...) thanks to the first elastic zone (OC). The strip thus placed at the limit of its elasticity does not exert high pressure, and it is therefore perfectly bearable. If the ankle joint is subjected, for example, to a varus of the hindfoot, this position cannot be reached thanks to the passage

  snapshot of the strip in the rigid state, the state from which a counter

  very important force opposing that which could cause the elongation of the ligaments and the sprain. In this position, the strip creates a barrier effect

  similar to plaster or any other rigid reinforcement.

  In phlebology and angiology, the strip according to the invention offers two advantages: - the possibility of placing the strip under controlled and known pressure, for example 30 hPa; the laying pressure is high and reproducible. - When walking, under the effect of the variation in volume of the muscles, it creates a pressure difference which facilitates circulation in the deep venous system. This effect is also caused by crossing the angular point (C). In the elastic zone (OC), the strip exerts the desired pressure, for example 30hPa. When the muscles swell, the "rigid" zone is reached, the textile material then opposes the variation of

  volume and pressure increases significantly, for example at 35hPa.

  In this regard, reference may usefully be made to Figures 1a and 1b. We know, by application of Laplace's law, that a band (1) which surrounds a member of which, for simplification, we will qualify the circular section exerts a pressure P = T / R, T being the tension of the band and R the

radius of the above section.

  Following a setting in motion of the muscular system, the radius R1 increases until the value R2, the band (1) then being

  subjected to an L2-L1 extension such that L2 / L1 = R2 / R1.

  -8- The bandage offers great resistance to compression exerted by muscle mobilization and the mobilization of

  joints which tend to vary R1 towards R2.

  With the use of a conventional strip, this variation from R1 to R2 increases the tension Ti originally given to the strip (1) in

  a T2 value normally fairly close to T1 (see Figure la).

  On the other hand, with the use of the strip according to the invention, if the tension given at the origin is maximum and such that it corresponds to the angular point (C), it is very clear that with any increase in Ri in R2 of the radius of the member surrounded by the band corresponds to a considerable increase in the tension from T1 to T2, even if the difference between R1 and R2 is

tiny (see Figure lb).

  The strip according to the invention then provides a significant massage effect in the surface and in depth, contributing to the reduction of

  venous stasis and accelerated flow.

  The massage effect is characterized by the pressure difference exerted by the elastic tissue between the position of the muscles at rest and the position under muscular effort. By developing the Laplace formula seen above, the relationship between the two pressures is of the form: T2 Ri

P2 = P1.

  Tl R2 For a variation of 5% of the circumference of the limb, for example at the ankle, and for a given band, the following results are measured by considering the curve tension / relative elongation of a conventional elastic compression band and the curve tension / relative elongation of an elastic compression band in accordance with the invention (the values indicated below

  are given for a recovery of two turns of each elastic band).

  Example 1 - Conventional elastic compression band R1 = 4 cm, R2 = 4.2 cm Elongation when laying 30% Two coiling turns Tension exerted for two turns: 50cN / cm x 2 = 100 cN / cm Tension exerted for two turns with the increase in elongation: 56 x 2 = 112 cN / cm -9-

112 4

  P2 = P1 .., ie P2 = 1.06 P1 4.2 Example 2 - Elastic compression bandage according to the invention Rl = 4 cm, R2 = 4.2 cm Elongation when laying 30% Two coiling turns Tension applied for two turns: 50 cN / cm x 2 = 100cN / cm Tension applied for two turns at change of slope (C): 84 x 2 = 168 cN / cm

168 4

  P2 = P1 ... or P2 = 1.60 P1 4.2 We observe a very significant pressure difference between the rest phase and the muscular effort phase. The strip which is the subject of the invention allows a saphenous filling to be rested by its elastic compression and, at the time of the change in slope (C), action on the deep veins. he

  it is therefore a real permanent muscular assistance.

  In other words, the strip according to the invention reconciles the advantages of elastic bands and stretch bands, without having the drawback of stretch bands which are known to lose very much.

  quickly their level of contention.

  It goes without saying that the invention is not limited to the single embodiment above, given by way of example; she kisses, at

  on the contrary, all possible variants of embodiments.

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Claims (6)

  1) Method for manufacturing a band (1) of elastic restraint of limited extensibility in the longitudinal direction, consisting in longitudinally combining, in a fabric constituting said band, elastic threads and inextensible threads, said inextensible threads being completely stretched when the elongation of said fabric is maximum, characterized in that: a) the elastic fabric formed by said elastic threads is a preexisting elastic fabric, b) said inextensible threads are inserted into said preexisting fabric by means of a sewing machine ( 2) forming points (4) arranged parallel to each other in the longitudinal direction of said strip (1), said preexisting fabric being subjected during stitching to a   predetermined relative elongation (AL / L).   2) A method of manufacturing a compression band (1) according to claim 1, characterized in that the points (4) are "chain stitch" type.   3) Manufacturing method of compression bandage   according to any one of claims 1 or 2, characterized in that said   strip (4) is manufactured continuously, the sewing machine (2) being fed upstream with the elastic fabric at a linear speed (Vl) lower than the linear speed (V2) of the receiving means (7) downstream, the relative difference of said   linear velocities (Vl, V2) being equal to the relative elongation (AL / L).   4) Device for manufacturing a compression band (1) specially designed for implementing the method according to one   any one of claims 1 to 3, characterized in that it comprises:   a) a first train (5) of traction cylinders (6), intended to supply said device with the elastic fabric, driven by a first tangential speed (Vl) adjustable, b) a sewing machine (2) intended to form points (4) with inextensible threads in said elastic fabric, c) a second train (7) of traction cylinders (8), intended to receive said elastic fabric after stitching, animated by a second tangential speed (V2) adjustable , and in that the relative difference between said first speed (Vl) and said second speed (V2) is equal to said relative elongation (AT / T).   -11-) Device for manufacturing a compression band according to claim 4, characterized in that the sewing machine (4) has a program for forming chains (4) arranged   parallel to each other in the longitudinal direction of the strip (1).   6) Device for manufacturing a strip (1) of   restraint according to any one of claims 4 or 5, characterized in   that the first and second trains (5, 7) of cylinders (6, 8) are driven by stepping motors whose control pulses are synchronized with the   sewing machine needle insertion cycle (2).   7) Restraint band (1) manufactured by the process   according to any one of claims 1 to 3 and by means of the device according to   any one of claims 4 to 6, characterized in that the slope of the   curve representing the tension of said strip (1) as a function of its relative elongation (L / L) increases suddenly for a value corresponding to said predetermined relative elongation, and becomes practically infinite. 8) band (1) of compression according to claim 7, characterized in that the chains (4) are placed in said elastic fabric   along broken lines when said elastic fabric is in the rest position.