US2017444A - Method of making elastic fabric - Google Patents

Description

2 Sheets-Sheet l Oct. 15, 1935. A. E. PAGE METHOD OF MAKING ELASTIC FABRIC Filed March 26, 1955 Oct. 15, 1935. A. E. PAGE 2,017,444

METHOD OF MAKING ELASTIC FABRIC Filed March 26, 1935 2 Sheets-Sheet 2 Patented Oct. 15, 1935 v UNITED STATES PATENT OFFICE METHOD or MAKING ELASTIC FABRIC Application March 26, 1935, Serial No. 13,078

11 Claims.

This invention pertains to textile manufacture and relates more particularly to a method of making fabric of highly elastic character, for example, fabric including rubber strands or yarns.

Elastic fabric, both knitted and woven, is useful for many purposes, in particular for the manufacture of constrictive apparel such as corsets, reducing girdles and bandages, hosiery, garter tops for hosiery, etc. and is made in accordance with at least two well recognized procedures,

to wit: (1) the disposal of tensioned highly elastic strands or threads interlaid between or among the usual constituent and relatively inelastic textile yarns constituting a woven or knitted fabric, said interlaid elastic strands forming no part of the essential fabric structure but merely acting to impart an artificial elasticity thereto; and 2) the employment of elastic yarns (for instance rubber filaments or threads with a helically wound textile covering) in substitution for or in association with one or more of the usual textile yarns or sets of yarns employed in actually making the fabric structure.

Whether or not the elastic fabric belongs to one or the other of said classes, and whether or not it is woven, knitted or otherwise fabricated, the

introduction of such highly elastic strand or yarn is always attended with difiiculty by reason of the inherent tendency of such elastic yarn to stretch excessively as compared with the usual textile yarns, so that especially designed tensions for the elastic strands and especially designed or acting take-ups for the fabricated material are, in most cases, requisite in the manufacture of such elastic fabrics. Even at best it is almost impossible to obtain elastic fabrics of uniform appearance and texture in accordance with the usual procedures, due to the above difiiculties, and also by reason of the inherent variations in elasticity of the rubber strands or yarns. In particular, in the manufacture of knitted fabric, the high stretch of the elastic strands, whether they be interlaid strands or whether they form the knitting yarns proper, makes it extremely difiicult to obtain the desired uniformity of width of the knitted fabric or to maintain uniformity of loop size or shape.

The present invention has for its principal object the provision of a novel method of making elastic textile fabrics whereby the desired uniformity of product may readily and certainly be obtained without recourse to the use of special forms of yarn feed, tension, fabric take-up or the like, the method being readily performed by slightly modified'construction;

usual machinery or with the assistance of hand actuated implements, if desired.

In the manufacture of covered rubber elastic thread or yarn for use inmaking textile fabrics in accordance with known procedures it has been 5 common to stretch the rubber filament to a predetermined extent and when so stretched to cover it with a spirally wound wrapping or wrappings of textile yarn or the like, and, after winding, to release the tension,the contact of the adjacent l0 coils of said helically wound cover limiting the contraction of the yarn, although this helically wound cover imposes no substantial limit to the stretch of the yarn. In accordance with the present invention, both contraction and stretch of the 15 thread are substantially fixed during the process of making the thread, and it is contemplated that for certain purposes it may be desirable to stretch the rubber filament to a greater or lesser predetermined degree preparatory to its association 20 with the stretch-limiting factor so that after its incorporation in the fabric and after the stretchlimiting factor has been rendered ineffective, the fabric may stretch to a predetermined degree dependent upon the percentage of preliminary 25 stretch to which the rubber filaments were subjected before covering.

The improved method, whereby the above object may be attained, as well as other supplementary objects and advantages hereinafter set Q forth, will be described in detail hereinafter and by reference to the accompanying drawings wherein Fig. 1 is a fragmentary side elevation of a composite thread useful in carrying the present 35 method into effect, showing its constituent elements and one mode of assembling them;

Fig. 2 is a view similar to Fig. 1 but showing a Figs. 3, 4, 5, 6 and 7 are transverse sections, to 49 larger scale, illustrating various modified constructions of composite elastic thread, useful in the practice of the present invention;

Fig. 8 is a fragmentary perspective view to large 5 scale illustrating a square rubber filament useful in making a thread for use in accordance with the present invention;

Fig. 9 is a fragmentary perspective view illustrating the filament of Fig. 8, as having been 50 stretched to a predetermined extent for the application of the helically wound covering;

Fig. 10 is a fragmentary perspective illustrating the filament of Figs. 8 and 9 after the covering has been applied and after the filament has been permitted to contract to such extent as is permitted by the covering;

Fig. 11 is a diagrammatic transverse section of a rib knitted fabric having incorporated therein, as an interlaid strand, a composite thread in accordance with the present invention;

Fig. 12 is a fragmentary front elevation to larger scale of the fabric of Fig. 11 showing its construction as knitted; I

Fig. 13 is a fragmentary front elevation of the fabric of Fig. 12 but showingthe effect of stretching this fabric laterally;

Fig. 14 is a view similar to Fig. 12 but illustrating a modified construction in which my improved composite thread constitutes the knitting yarn itself and showing the knitted fabric as it is formed upon the needles of the knitting machine;

Fig. 15 is a view similar to Fig. 14 but showing the fabric after it has been stretched laterally and longitudinally; and

Fig. 16 is a fragmentary front elevation showing the top of a stocking having an elastic garter strip knitted therein in accordance with my improved method. v

Referring to the drawings, character S indicates my improved composite yarn useful in the manufacture of any desired textile fabric, for example, a woven or knitted fabric. As illus trated in Fig. 1, this yarn comprises a relatively large and very stretchable strand l, for example a thread or filament of rubber, such as might be prepared by the extrusion of latex in accordance with known methods, while the numeral 2 indicates a textile strand relatively inextensible as compared with the filament l and of any suitable material such as cotton, wool, silk, rayon or a mixture of textile fibers or of any of the other fibrous textile materials or artificially prepared filaments such as are now commonly prepared from derivatives of cellulose. As illustrated in Fig. 1, the strands I and 2 are laid in substantially parallel relation and are bound together by a helical-1y wound covering 3 which may likewise be of any desired textile material such as cotton, .silk, wool, or the like, and which may be laid in a close or open helix as preferred. Instead of using a filament of substantially circular cross section, as shown in Figs. 1 and 3, I

may, if desired, employ a substantially square rubber thread I as illustrated in Figs. 4 and 8, such as is commonly prepared by cutting sheet rubber and such as are commonly used in the preparation of elastic webbing or the like. As illustrated inFigs. 8, 9 and 10, it is preferred, in preparing my composite thread, to subject the strand I" to a substantial initial tension so as to elongate it to a predetermined degree prior to the application of the helical covering 3. This covering, when applied, constricts the strand I and when the tension on the latter is relieved after the covering operation is complete, the contact of the adjacent coils of the helically wound strand 3, as illustrated in Fig. 10, limits contraction of the rubber strand I to a predetermined extent so that in the completed thread the strand i is of a less cross-sectional area than the original strand I. However, unless the strand I has been stretched to an abnormal extent during the covering operation, the covered strand is free to extend under tensioning stress to a substantial degree, the amount of stretch of which the covered strand is capable being substantially determined by the percentage to which the rubber filament I is elongated during the covering operation.

As illustrated in Fig. 2 the composite strand may have, in addition to the spiral wrapping 3,

one or more additional spiral wrappings 4, prefer- 6 of a ribbon bent to form an annulus enclosing the inextensible strand 2, the parts being bound together and held in the shape shown by means of the helical coil or coils 3. 15

In Fig. 6 a further modification is illustrated in which the rubber strand I is of substantially elliptical cross-sectional contour, while in Fig. 7 the rubber strand I e is of substantially rectangular form and has associated therewith symmetrically disposed inextensible strands 2 and 2' the several strands being bound together by the helica] covering 8.

Whatever thespecific construction chosen as above suggested, the resultant thread is normally substantially inextensible by reason of the inclusion' of theinextensible constituent yarn 2. Being thus inextensible, the thread may be treated in the process of textile manufacture like any other textile yarn or strand and requires no 0 special tension or other machine elements for its manipulation.

Thus as illustrated in Fig. 11, this strand 8 may form an interlaid strand in a knitted fabric which structurally comprises the textile strand 5 85 knitted upon two sets of needles to form a rib fabric having the front wales 6 and the rear wales l, the interlaid strand S being disposed between the front and rear faces of the fabric and being laid transversely between the runs of the yarn 5, but without taking any part in the fabric structure and without entering the needle loops.

When such a fabric has been knitted, as illustrated in Fig. 12, the inextensible yarn 2 is still continuous and the knitted fabric is even less elastic than an ordinary knitted fabric of textile material by reason of the inclusion of the transversely extending inextensible interlaid strands S. After the fabric has been completed it is subjected to a heavy tension in a direction at right angles to the wales, as shown by the arrows in Fig. 13, this tensional stress being so severe as to rupture the strand 2 so that the latter is left in discontinuous fragments 2 (Fig. 13). The stretch-limiting yarn 2 thus becomes substantially ineffective; the initial elasticity of the strand i being restored so that in the thus completed fabric the strand S functions in the same way as any elastic gut strand of the prior art. However, as above pointed out, the incorporation of this strand offers no difficulties in the process of manufacture and the resulting fabric is of better appearance than it has heretofore been possible to provide in an elastic fabric of this general type.

In Figs. 14 and 15 a modification is illustrated in which the composite thread, such as above described, itself forms the knitted loops of the fabric. During knitting, this thread is inextensible and is treated like any other textile knitting yarn, but after the fabric has been completed it may be subjected to powerful stretching stres transversely, thus rupturing the inextensible strand 2 and reducing it to short fragments as shown at 2 in Fig. 15. Thereupon the fabric becomes elastic in both directions and, in accordance with this method of procedure, may be made very uniform and without recourse to any special tensions, take-up or the like.

In Fig. 16 a top T of a stocking is shown as having a garter strip 8 knit in near the top by the use of my improved thread S. This thread may be knitted in in accordance with either of the methods illustrated in Figs. 12 or 14 respectively, and forms an area which, when removed from the needles, does not tend to contract as much as the usual knitted material. This area 8, constituting the garter strip. is now subjected to a, strong lateral tension which ruptures the inextensible element 2 of the strand 8 so as to restore the elasticity to said strand inherent in its rubber constituent yarn. This garter strip is highly elastic and in the normal and intended manner assists in holding the stocking in place on the leg of the wearer.

While the invention has above been described with particular reference to the manufacture of a knitted fabric, it will readily be understood by those skilled in the art that it is applicable as well to the preparation of woven or other fabrics. Other and additional utilities for my improved method and utilities will be apparent to those skilled in the art, as well as further modifications of materials and modes of asembling them, all within the scope of the invention as defined in the appended claims.

I claim:

1. That method of making elastic textile fabric which comprises as steps preparing a composite substantially inextensible yarn including a strand of normally stretchable material, and limiting means operative substantially to prevent stretch of said strand, manipulating said yarn in accordance with any selected procedure thereby to cause said strand to become a constituent part of a textile fabric of predetermined type, and thereafter rendering said limiting means substantially ineffective so as to free the stretchable strand to stretch in normal manner in response to applied stress.

2. That method of making an elastic textile fabric which comprises as steps preparing a thread by associating a normally elastic yarn with limiting means operative temporarily substantially to prevent it from stretching and with an outer covering capable of elongation, causing said thread to become a constituent element of textile fabric of predetermined type, and thereafter subjecti ng said fabric to mechanical treatment operative to destroy the continuity of said limiting means, thereby to free the elastic yarn to stretch in response to elongating stress.

3. That method of making elastic textile fabric which comprises as steps preparing a thread by so associating a normally elastic yarn with a substantially inelastic yarn that the elastic yarn is unable substantially to elongate in response to applied tensile stress, so manipulating said thread as to cause it to become a constituent element of textile fabric of predetermined type, and thereafter subjecting the fabric to a force so applied as to destroy the continuity of the inextensible constituent yarn of said thread, thereby to permit the elastic yarn to strech in response to tensile stress.

4. That method of making an elastic knitted fabric which comprises as steps preparing normally inextensible threads by so associating an elastic yarn with a substantially inelastic yarn that the resultant thread is substantially no more capable of stretching than usualstextile yarns, knitting ribbed fabric from textileyam while interlaying the so prepared thread between the front and rear wales. of the fabric, and, after .5

completion of the knitting operation, subjecting the fabric to stress applied in a widthwise direction of sumcient intensity to rupture the inextensible constituent yarn of the interlaid thread, thereby to restore the normal capability to stretch 10 to the elastic constituent yarn of the gut thread.

5. That method of making an elastic knitted fabric which comprises as steps preparing normally an inextensible composite thread by so associating an elastic yarn with a substantially l5 inelastic yarn that the resultant thread is substantially no more stretchable than usual textile yarns, knitting said composite thread to form loops of the desired knitted fabric, and thereafter so tensioning the fabric as to rupture the 2) inextensible constituent yarns of the loop-forming composite thread, thereby to permit the elastic component of said thread to stretch freely.

6. That method of mfiking an elastic knitted fabric which comprises as steps preparing 9, nor- 26 mally inextensible composite thread by assembling an elastic yarn, while the latter is elongated to a predetermined extent less than its maximum possible elongation, with a substantially inextensible yarn, wrapping said yarns with a helically 30 wound covering strand, knitting the composite thread to form loops of the desired knitted fabric, and thereafter subjecting said fabric to tension such as to rupture the inextensible strand of said composite yarn, thereby to permit the elastic constituent of said yarn freely to stretch.

'7. That method of making an elastic knitted fabric which comprises as steps preparing a normally inextensible composite thread by assembling an elastic yarn, while the latter is at less 40 than its maximum possible elongation, with a substantially inextensible yarn, wrapping said yarns with a helically wound covering strand whose turns are so disposed as substantially to prevent contraction of the elongated elastic constituent strand, forming knitted loops from yarn of any desired character thereby to produce a coherent knitted fabric, and, while so forming said knitted loops, introducing said composite thread as an interlaid strand held in place by the loop-forming yarn but not included in the loop construction.

8. That method of making a textile fabric which comprises as steps preparing a composite thread including a normally stretchable strand and a limiting element or elements which prevent its elongation beyond a predetermined degree, incorporating said thread in a fabric by any desired method, and thereafter rendering said limiting element or elements ineffective, thereby to permit-the elastic constituent element to stretch.

9. That method of making an elastic fabric which comprises as steps associating a normally stretchable yarn with a substantially nonstretchable yarn, and enclosing said yarns in a stretchable covering thereby to produce a normally non-stretchable thread useful in making a textile fabric by known methods of procedure 70 which becomes elastic upon rendering ineffective the non-stretchable constituent of said thread, and incorporating said thread in a textile fabric.

10. That method of making an elastic fabric which comprises as steps preparing a composite 15 substantially non-stretchablethread including a normally stretchable yarn, and a helically wound stretchable covering therefor, and .means vnormally eifective substantially to prevent stretchin; of said thread, said stretch-preventing means being of a character such as to permit it to be made non-eifective after incorporation of the thread in a textile fabric by known methods, incorporating said thread in a textile fabric, and thereafter rendering the stretch-preventing means ineffective.

11. That method of making an elastic fabric which comprises as steps preparing a composite substantially non-stretchable thread including a stretchable yarn, and means normally effective substantially to prevent substantial elongation of the stretched yarn, said means for preventin: further elongation beinz of a character such as to permit it to be made ineifective by the application of tensile stress after incorporation of the thread in a textile fabric, incorporating said thread in a textile fabric, and applying tensile stress to the fabric sumcient to destroy the efl0 fectiveness of the elongation-preventing means.

ALBERT E. PAGE.

Images