US3314251A

US3314251A - Elastic fabric

Info

Publication number: US3314251A
Authority: US
Publication date: 1967-04-18
Anticipated expiration: 1984-04-18

Description

su f.. x

A. BNGER ELASTIC FABRIC Filed Dec.

April 18, 1967 l lllll United States Patent Ofifice 3,3i4,25l Patented Apr. 1S, 1967 1e Claims. (in. 6ft- 193) The present invention relates to an elastic fabric, and more particularly to a warp knitted fabric made elastic by elastic threa-ds extending in Warp direction.

Fabrics of this type have longitudinally extending Wales formed of looped threads and extending in warp direction. According to the prior art, an elastic thread passes through the loops of each Wale, and is connected to the loops.

When fabric according to the prior art is made narrow and band-shaped, the narrow fabric bands have a ten-dency to roll up or curl in transverse direction. Even by finishing operations, it is not possible to completely eliminate the curved shape of the fabric, and to produce a fiat band.

It is one object of the invention to overcome this disadvantage of elastic fabrics, and to provide a fabric which is produced in fiat condition, and remains fiat during use without any tendency to warp or curl.

Another object of the invention is to connect elastic threads to each Wale ofthe fabric in such a manner that the elastic threads hold the finished fabric in a flat condition.

Another object of the invention is to produce a flattening force on the fabric by elastic threads wound in opposite direc-tions about portions of the stitches of the Wales of the fabric.

With these objects in View, a fabric according to the present invention comprises a thread forming a Wale of successive interconnected stitches, and two elastic threads extending through and within said interconnected stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads being connected to at least some of said stitches and exerting due to their symmetrica] arrangement on said Wale forces counterbalancing each other so that the fabric is flat.

The term symmetrical is used in the present application to include two threads having the same turns and loops staggered and shifted in axial direction of the Wale relative to each other.

In the preferred embodiment of the invention, each stitch includes a loop portion and a connecting portion connecting the end of each loop portion With the beginning of the following loop portion, and the elastic threads pass through the loop portions and are wound in opposite directions about the connecting portions of selected stitches.

In one embodiment of the invention, each elastic thread is Wound about the connecting portions of a first series of alternate stitches, and the other elastic thread is Wound about the connecting portions ofthe other set of alternate stitches.

In -another embodiment of the invention, the elastic threads are Wound in opposite directions about the con necting portion of each stitch of the Wale.

Tests have shown that a fabric made in accordance with the present invention, will not roll up, Warp, or curl in transverse direction, and will remain fiat after finishing operations such as sizing and dressing. The curling effect produced by the single elastic thread of the prior art, is compensated by the effect of the second elastic thread acting on the same Wale.

Further surprising advantages of bands made in accordance with -the present invention as compared with the bands of the prior art have been found. When an elastic thread breaks in the fabric of the invention, it does not slip into the loops of the respective Wale by resilient contraction, which is the case in known fabrics of this type Where there is a single elastic thread provided for each Wale. Furthermore, When a band comprising a plurality of wales with two elastic threads, and interconnecting binding threads between the wales, is expanded in longitudinal direction, the transverse width of the band remains almost the same, whereas band-shaped fabric according to the prior art having only single elastic thread for each Wale, substantially contract in transverse direction so that the b-and Width is reduced as the length of the band is increased by longitudinal pull.

While this effect is particularly noticeable for narrow fabrics, such as bands or braid-like fabrics, a lesser transverse constriction has been noted for wide fabrics as Well.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, Will be best understood from the following'description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. l is a schematic fragmentary view on an enlarged scale illustrating a fabric according to one embodiment of the invention;

FIG. 2 is a fragmentary schematic view on an enlarged scale illustrating a modified embodiment of the invention; and

FIG. 3 is a fragmentary schematic view illustrating another embodiment of the invention on an enlarged scale.

Referring now to the drawings, and more particularly to FIG. l, the fabric is Warp-knitted and comprises looped threads 2 forming Wales, pairs of elastic threads 4 and 5 connected to each Wale, and a weft thread 3.

Each Wale is composed of a series of successive stitches, each stitch including a loop portion 7, and a connecting portion 6a connected to the end of each loop portion 7 by a knee 6 and being connected to the beginning of the next following loop portion 7. Threads 2 are nonelastic, but Wales 1 are elastic in longitudinal direction due to the loop construction. The illustrated loop construction is generally referred to las 2-0/9-2 or Il 0/0 II. The weft threads 3 pass in opposite transverse directions through transverse rows of stitches formed by corresponding stitches of the wales.

A pair of elastic threads 4 and 5 passes through the loops of each Wale 2. The elastic thread 4 is Wound in a turn about the connecting portion 6a of a tfirst series of alternate stitches, while the elastic thread 5 of the same Wale is Wound in a turn about the connecting portions 6a of a second series of alternate stitches lso that elastic threads 4 and 5 are connected to alternate stitches only whereby each elastic thread passes straight through a loop 7 of a stitch about whose connecting portion 6a the other elastic thread is Wound. Furthermore, threads 4 and 5 are Wound in opposite Winding directions about the respective connecting portions 6a of alternate stitches. While the turns of threads 4 and 5 are symmetrical, they are staggered in the axial direction of the Wale. The respective thread 4 or l5 is wound about the respective connecting portion 6a above the knee portion 6 and is held between the respective loop portions 7 and the knee portion 6 of the next following stitch passing under both legs of the U-shaped knee portion 6 and over loop portion 7.

Elastic threads 4 and 5 may be made of rubber, or of a synthetic elastic material. It is also possible to use an elastic filament in a braided or spun envelope, or to form an elastic thread of two or more elastic filaments, each of which may be provided with a tubular envelope.

While the elastic threads are shown in the drawing to be wound and twisted, it will be understood that the elastic threads are actually straight in the normal condition of the fabric, and that the non-elastic threads 2 will coil about the straight elastic threads.

The embodiment of FIG. 2 corresponds to the embodiment of FIG. 1 in every respect as far as the connection between the non-elastic threads 2 and the elastic threads 4 and 5 is concerned. However, instead of providing a weft thread 3, a binding thread 8 connects adjacent wales. Each binding thread 8 passes through the loop portion 7 of a stitch of one Wale and then forms a loop 8o superimposed on the loop portion of the next following stitch of the same wale whereupon it passes through the loop portion of a stitch of the other adjacent wale, and then forms another loop 8o superimposed on the loop portion of the next following stitch of the same wale. It will be appreciated that a fabric constructed in accordance with FIG. 2 is more resilient in transverse directionthan the fabric illustrated in FIG. 1

FIG. 3 illustrates another embodiment of the invention. Only one wale 11 is shown, and it will be understood that a plurality of wales 11 is provided in the fabric, and are connected either by a weft thread 3 as shown in FIG. 1, or by binding thread 8 as shown in FIG. 2.

The wales of the embodiment shown in FIG. 3 are made of non-elastic threads 12 with loop portions 7 and connecting portions 6a as described with reference to FIGS. 1 and 2. Two elastic threads 9 and 10 are connected with the stitches of each wale 11. While in the embodiments of FIGS. 1 and 2, each elastic thread is connected to connecting portions of alternate stitches, both elastic threads 9 and 10 are wound about the connecting portions 6a of each stitch of the Wale. Elastic threads 9 and 10 are wound in opposite direction so that the torques produced by the elastic threads compensate each other. Elastic thread 10 passes under a connecting portion, then over a connecting portion, over a loop por tion and again under a connecting portion, while elastic thread 9 passes under a connecting portion, over the knee portion 6 of the next following loop, over the loop portion of the first stitch and then under the connecting portion 6a of the next following stitch.

The resilient warp fabric according to the invention is made on a warp knitting machine, and more particularly on a Raschel machine, which has a needle bar and six guide bars. A guide bar is used for each thread of the fabric, and since in the fabric of the present invention only four

threads

2, 4, 5, and 3 or 8 are used, only four guide bars are operated during the knitting of the fabric. A needle of the needle bar is used for making each Wale. The guide bars have openings through which the respective threads are guided, and stitches are formed by vertical movement of the needles and by horizontal movements of the guide bars.

An elastic fabric according to FIG. 2 is made in the following manner:

Assuming that the rst guide bar guides all threads 2, of all wales, the second guide bar guides all threads 8, the third guide bar guides all elastic threads 4, and the fourth guide bar guides all elastic threads 5. Two guide bars of the machine remain inoperative.

Assuming that the first needle of the needle bar produces the wale on the right of FIG. 2, the spaces before and between the wales are indicated O, II, IV, VI. These spaces correspond to spaces between the needles which make the wales, respectively. When the fabric of FIG. 2 is made in the direction of the arrows, all stitches of row a are simultaneously made, while in the following operation all stitches of the next row of stitches b ,are made. The third row is again made as row a, and the fourth row again made as row b. Therefore, the operation which will now be described with reference to rows a and b will be repeated. Also, the operation which produces the first wale, is also carried out for producing all other wales.

The time required for the formation of a row a or b of stitches, is divided into a first operational period before the loop formation, and a second operational period after the loop formation.

OPERATION Formation of 2z row of loops a The first guide bar with thread 2 is moved from the space II to the space 0. The second guide bar for threads 8, moves during the first operational period from space II to space IV, cooperating with the middle Wale shown in FIG. 2, and during the second operational period from space IV to space II. The rst elastic thread 4 is controlled by the third guide bar to stay in space II. The second elastic thread 5 controlled by the fourth guide bar is removed from the path of the loop forming thread 2 by being moved during the first operational period from space 0 to space II, and during the second operational period from space II to space 0.

Formation of the row of loops b The loop forming threads 2 of the first guide bar are shifted from the space 0 to the space II. The connecting threads 8 in the second guide bar are moved from `space II to space 0 during the first operational period, and from space 0 to space II during the second operational period. The elastic thread 4 of the third guide bar is moved out of the path of movement of the loop forming thread 2 by being moved during the first operational period from the space II to the space 0, and during the second operational period from the space 0 to the space II. The other elastic thread 5 is held by the fourth guide bar in the space 0.

METHOD FOR MAKING THE FABRIC ACCORDING TO FIG. 1

Threads 2, 4 and 5 are again controlled by three guide bars. as explained above. In this embodiment, no connecting threads S, but weft threads 3 are used for connecting the wales. Weft threads 3 may connect a great number of wales of a wide fabric before being reversed in the following pit in the manner shown on the left of FIG. 1. The picking of the weft is carried out by a picking device provided on a Raschel machine which inserts the weft during each loop formation across the width of the warp knitted fabric. If the fabric is narrow, and the reversing points of the weft thread are not far apart, one of the free guide bars can be used for inserting the weft.

By way of example, and for the sake of simplicity it may be assumed that the fabric is narrow and is composed of only three wales, as shown in FIG. 1, so that the weft thread has to be reversed on the right of the first wale. Assuming as before, that threads 2, 4 and 5 are controlled by the first, third and fourth guide bar, and that the `weft 3 is controlled by the second guide bar, the fabric of FIG. 1 is made in the following manner:

OPERATION Formation of the loops of row a' Threads 2, 4 and 5 are operated by the first, third and fourth guide bars as explained with reference to the fabric of FIG. 2. The second guide bar operating the weft 3 moves during the first operational period from space 0 to space VI.

Formation of the loops of row b' Threads 2, 4 and 5 are operated by the lirst, third and fourth guide bars as explained with reference to row b of FIG. 2. The second guide bar moves the weft thread 3 during the first operational period from the space VI to the space 0.

METHOD OF MAKING THE FABRIC ACCORDING TO FIG. 3

It will be understood that several Wales form a fabric OPERATION Form'aton of the loops of row a The rst guide bar with loop forming thread 12 operates as described for the embodiment of FIG. 2 for threads 2 forming the row of loops a.

The second guide bar with elastic thread 9 moves out of the path of movement of the loop forming needle during the first operational period by being moved from space 0 to space II, and remains in the space 1I during the second operational period. The third guide bar with the other elastic thread 10 moves out of the path of the loop forming thread 12 during the first operational period by moving from space 1I to space 0 and remains during the following second operational period in the space 0.

Formation of the loops of row b Thread 12 is operated by the first guide bar as described for threads Z'making row b of FIG. 2. Thread 9 of the second guide bar is moved from space Il to space O during the first operational period, and remains during the second operational period in the space 0. At the same time, the elastic thread 10 is moved by the third guide bar from space 0 to space Il, and remains during the second operational period in the space ll.

It will be understood that the elastic threads 9 and 10 of the fabric of FIG. 2 are connected to all stitches of each wale by different connections in a mirror symmetrical manner, and that the elastic threads 4 and 5 of the embodiments of FIGS. l and 2, are respectively counected with first and second series of alternate stitches by different connections whose projections on a plane perpendicular to the wales are mirror Vsymmetrical so that in all embodiments of the invention, counterbalancing forces are exerted by each pair of elastic threads in a Wale to hold the fabric in a at condition.

The same stitch is illustrated in all embodiments of the invention, but it will be understood that modified stitches can also be used in combination with two resilient threads in accordance with the invention.

The fabrics according to the present invention may be further modied by connecting the wales by binding threads forming loops. The weft thread need not extend across the entire width of the fabric, as explained with reference to FIG. l, but may extend only through parts of the fabric so that slits are formed between adjacent wales permitting the use of the fabric band for the edge of a buttonhole. Each Wale may be formed of a series of two or more interconnected stitches of the nonelastic thread. While the flattening effect of the tWo elastic lthreads of the present invention is particularly no` ticeable for band-shaped fabrics, it is also effective when fabrics of greater width are made in acordance with the present invention, for example elastic fabrics of the type used for foundation garments.

It will be understood that each of the elements described above, or two or more together, may also nd a useful application in other types of elastic fabrics differing from the types described above.

While the invention has been illustrated and described as embodied in a warp-knitted band including a plurality of wales made of a non-elastic thread and of two elastic threads, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such applications should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A fabric comprising a thread forming a wale of successive interconnected stitches; and two elastic threads extend through and within said interconnected stitches symmetrically to a central plane passing through the axis of said wale, said elastic threads being connected to at least some of said stitches and exerting due to their symmetrical arrangement on said Wale forces counterbalancing each other so that the fabric is flat.

2. A fabric comprising a thread forming a wale of successive interconnected stitches; and two elastic threads extend through and within said interconnected stitches, one of said elastic threads being connected with the stitches of a rst series of alternate stitches and the other elastic thread being connected with the stitches of a second series of alternate stitches of said stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads exerting due to their symmetrical arrangement on said wale forces counterbalancing each other so that the fabric is flat.

3. A fabric comprising a thread forming a Wale of successive interconnected stitches; and two elastic threads extending through and within said interconnectedstitches, said elastic threads being connected to each of said stitches symmetrically to a central plane passing through the axis of said wale, said elastic threads exerting due to their symmetrical arrangement on said wale forces counterbalancing each other so that the fabric is flat.

4. A fabric comprising a thread forming a wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion with the beginning of the following loop portion; and two elastic threads extend through and within said loop portions and wound in opposite directions about said connecting portions of selected stitches symmetrically to a central plane passing through the axis of said wale, said elastic threads exerting due to their symmetrical arrangement on said wale forces counterbalancing each other so that the fabric is flat.

5. A fabric comprising a thread forming a wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion with the beginning of the following loop portion; and two elastic threads passing through said loop portions, one of said elastic threads being wound about said connecting portions of a rst series of alternate stitches of said stitches and the other elastic thread being wound about said connecting portions of a second series of alternate stitches of said stitches.

6. A fabric comprising a thread forming a wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion with the beginning of the following loop portion; and two elastic threads extend through and within said loop portions, one of said elastic threads being wound about said connecting portions of a rst series of alternate stitches of said stitches and the other elastic thread Abeing wound in a winding direction opposite to the winding direction of said one elastic thread about said connecting portions of a second series of alternate stitches of said stitches symmetrically to a central plane passing through the axis of said wale, said elastic threads exerting due to their symmetrical arrangement on said wale forces counterbalancing each other so that the fabric is flat.

7. A fabric comprising a thread forming a wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion With the beginning` of the following loop portion; and two elastic threads extend through and Within said loop portions and Wound about said connecting portions of each of said stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads exerting due to their symmetrical arrangement on said Wale forces counterbalancing each other so that the fabric is ilat in opposite Winding directions.

8. A Warp-knitted fabric comprising a plurality of Warp threads, each Warp thread forming a Wale of successive stitches, each stitch including a loop portion and a connecting7 portion connecting the end of each loop portion With the beginning of the next following loop portion; two elastic threads extend through and Within said loop portions of said stitches of each Wale and Wound in opposite directions about said connecting portions of selected stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads exerting due to their symmetrical arrangement on said Wale forces counterbalancing each other so that the fabric is flat; and binding thread means connecting said Wales.

9. A Warp-knitted fabric comprising a plurality of Warp threads, each Warp thread forming a Wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion with the beginning of the next following loop portion; tWo elastic threads extend through and Within said loop portions of said stitches of each Wale and Wound in opposite directions about said connecting portions of selected stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads exerting due to their symmetrical arrangement on said Wale forces counterbalancing each other so that the fabric is fiat; and a binding thread connecting each pair of adjacent Wales and passing through said loop portion of a stitch of one of said adjacent Wales and forming a loop superimposed on said loop portion of the next following stitch of said Wale, and then passing through the loop portion of t-he other adjacent Wale and forming a loop superimposed on the loop portion of the next following stitch of the other Wale.

10. A Warp-knitted fabric comprising a plurality of Warp threads, each Warp thread 4forming a Wale of successive stitches, each stitch including a loop portion and a connecting portion connecting the end of each loop portion With the beginning of the next following loop portion; tWo elastic threads extend through and Within said loop portions of said stitches of each Wale and Wound in opposite directions about said connecting portions of selected stitches symmetrically to a central plane passing through the axis of said Wale, said elastic threads exerting due to their symmetrical arrangement on said Wale forces counterbalancing each other so that the fabric is at; and a binding weft thread passing in opposite directions transversely to said Wales through transverse rows of said stitches of said Wales.

References Cited by the Examiner UNITED STATES PATENTS 12/1926 Great Britain. 9/ 1938 Great Britain.

MERVIN STEIN, Primary Examiner.

W. CARTER REYNOLDS, Examiner.

Claims

1. A FABRIC COMPRISING A THREAD FORMING A WALE OF SUCCESSIVE INTERCONNECTING STITCHES; AND TWO ELASTIC THREADS EXTEND THROUGH AND WITHIN SAID INTERCONNECTED STITCHES SYMMETRICALLY TO A CENTRAL PLANE PASSING THROUGH THE AXIS OF SAID WALE, SAID ELASTIC THREADS BEING CONNECTED TO AT LEAST SOME OF SAID STITCHES AND EXERTING DUE TO THEIR SYMMETRICAL ARRANGEMENT ON SAID WALE FORCES COUNTERBALANCING EACH OTHER SO THAT THE FABRIC IS FLAT.