US1864345A - Elastic strand - Google Patents

Description

' June 21, 1932. J FQX I L 4 345 ELASTIC STRAND Filed April 1, 1951 J'u/ni07' Willzlam cfFo l strands formed of covered rubber and ar-- Patented June 21, 1932 UNITED STATES PATENT osslcs WILLIAI 3'. FOX, 01' PHILADELPHIA, PENNSYLVANIA, ASSIGN'OB TO JAMES B.

KENDRICK 00., 1110.0! Q PENNSYLVANIA PENNSYLVANIA, A CORPORATION 03' nus-rm s'rnann I Application fled a -u 1, 1931. semi no. 528,919.

This invention relates to improvements in elastic fabrics of the character employed in themanufacture of wearing apparel and surgical appliances and comprising elastic ranged side by side and held in place by cooperating binding threads, the elastic strands being enclosed in pockets formed between adjacent binding threads in a manner to permit the fabrics in their entireties to be stretched in directions longitudinally of their elastic strands. J

The rubber cores of the elastic strands employed in such fabrics have been retained therein in a condition stretched longitudinally from their normal lengths before being covered and they have been held insuch stretched condition by the coverings enclosing the same independently of the binding threads of the fabric. Even though the coverings of the rubber cores hold. them in a stretched condition in the'fabric of which they form 'a part the stetched condition .in which they are thus held is far from the limit to which theymay be stretched when the elastic fabric is stretched from its normalv condition, and the limit to which the elastic fabric as a whole may be stretched is well within the limit to which the elastic strands could be stretched in the absence of the binding threads.

When pieces. of fabrics of the character above described are sewed together or. sewed to pieces of other materials, it frequently happens that the needle used in the sewing operation penetrates some. of the rubber cores of the elastic strands, sometimes leaving the sewing thread extending through the cores, and sometimes merely leaving holes or broken edge portions in the cores; and the frequent stretc ing and release of the elastic fabric of the article of wearing apparelor the surgical through'the pockets containing them and the points of breakage not onlyv continued stretching and release of the elastic fabric; and this continued stretching'and release of the fabric has caused the end porthereof to protrude from within the main body of the fabric, thereby not. only impairing the efliciency of the article or appliance, butalso rendering it rough and unsightly. I The object of'my invention is to overcome the aforesaid objection, by the provision of an elastic strand provided with a rubber core having a novel covering and by combinin the core and the novel covering thereof wit other elements of the fabric to form a product in which the extent of the recession of the covered rubber cores from the pointsv of breakage will be greatly reduced or entirely eliminated, thereby greatly reducing the number and size of the protruding end portions of broken rubber cores, or eliminating them entirely from the fabric. A The invention resides in the novel fabric and in the novel elements thereof hereinafter described and claimed.

In the accompanying drawing, illustrating my invention,

Figure 1 is a front view of a piece of elastic fabric, enlarged, embodying my invention. a Figure 2 is a side view of a part of one of the elastic strands 'of the fabric, greatly enlarged ,showing certain portions of the covering threads unwrapped from the core and broken.

Fi re 3 is a side view of a part of one of the e astic strands, greatly enlarged, showing the core thereof stretched to the condiwrapped therefrom and broken.

Referring to the drawing, the elastic fab ric comprises elasticstrands 2, arranged side bv side, and cooperating binding threads 3.

The strands 2 are bound within the fabricand held in place in their side bYNSldG relationship therein by the binding threads 3 tions of the cores resulting from the breaking which, as herein illustrated, as knitted together, forming a network extending throughout the fabric and enclosing the strands 2 in pockets formed by and between the loops of the adjacent binding threads. I The fabric as thus far described may be lpjlloduced by the aid of either a straight itting machine or a circular knitting machine in the usual manner well known in this art. i

Each elastic strand 2 comprises a central strand or core 4 of rubber, a set of threads 5 wrapped spirally.around the core, a set of threads 6 wrapped spirally around the core reversely of the threads of the first named set and in alternate succession with relation thereto, and a plurality of other threads 7' wrapped spirally in the same direction around the core 4 and the two sets of threads 5 and 6 thereon. I

In the present embodiment of my invention there are three threads in the set 5, two threads in the set 6 and five threads in the plurality of outerthreads. Y

The core 4 of each strand 2 is stretched longitudinally beyond the normal length thereof before the application of the sets of threads 5, 6 and 7 thereto, and it is prevented its normal length, and while it is held in from returning to such normal length by said threads and particularly by the two sets of threads 5 and 6. a

In producing each elastic strand 2, the rubber core 4 thereof is stretched longitudinally to a lengthequal to about five times this stretched condition the sets of threads 5, 6 and 7 are applied thereto as shown in Fig. 3. When the'core 4 is released from the stretched condition shown in Fig. 3, after the application of the threads, the core 4 I contracts longitudinally and expands trans- .versely and returns to a length which is equal to somewhat less than three times its normal length as shown in Fig. 2, and, in this con- .dition, its further return to-its normal length is prevented by the sets of threads 5, 6 and 7 but almost wholly by the two sets of threads 5 and 6.

i In applying the three sets of threads 5, 6

i and 7 to the rubber core 4 of each strand 2,

while the core is held in a condition stretched to about five times its normal length as I shown in Fig. 3, the innermost thread 8 of the set of threads 5 is first wrapped spirally around the bare core 4, the innermost thread 9 of the other set of threads 6 is then wrapped around the core 4 and the innermost thread 8 thereon reversely of .the last named thread, the thread 10 next to the innermost thread 8 of the same set 5 thereof is then wrapped spirally around the core 4 and the innermost threads 8 and 9 of the two sets of threads 5 and 6, reversely of the thread 9 immediately preceding it, the thread 11 next to the innermost thread 90f the same set 6 thereof is then wrapped spirally around the core 4 and the threads previously wrapped diately preceding it, and thereafter the thread 12 of the set 6 is wrapped spirally around the core 4 and the threads previously wrapped thereon reversely of the thread 11 immediately preceding it; and finally the plurality of threads 7 are, in parallel relationship, wrapped spirally around the core and the threads of-the two sets of threads 5 and 6 previously wrapped thereon, reversely of the last preceding thread 12. I

After the three sets of threads 5, 6 and 7, have been applied to the core 4, as abovedescribed, for the production of each strand 2, the entire strand is released and permitted to contract longitudinally to the condition shown in Figs. 1 and 2.

In effect the set of threads 6 contains three threads, because it will be understood that the outermost thread 12 of theset 5 in being wrapped around the core 4 andthe threads previouslywrapped around the same and reversely of the thread 12.

The threads ofthe three sets 5, 6 and 7 may be formed of cotton or. other suitable material. I 7 V The threads of the set 7, five in number as herein illustrated, of each elastic strand 2,

arewrapped around the core 4 and the set of threads 5 and 6 thereon in the same direc-- tion, and, in the normal condition of the entire elastic strand-2, the convolutions of the threads of the set 7 are held in close relationship and provide arelatively smooth and even exterior surface for the elastic strand. I have discovered that when pieces of fabric made in accordance with my invention, as

hereinbefore described, are sewed together i v or to pieces of other fabric in the manufacture of articles of wearing apparel and surgical appliances, and such articles and appliances are in service, and one or more of the rubber cores of the elastic strands of the fabric are broken, the extent of the recession ofthe end portions of thebroken cores from thepoints of breakage will be greatly reduced as compared with elastic strands having covered ceding through the covering threads andthe ,covering threads from being easily disturbed from their binding positions on the cores when either. thecores or threadsor both are cut or broken,

rubber come as now generally-employed in l-so asses;

I claim- 1. An elastic strand comprising a rubber core and two sets of covering threads thereon,

the threads of each set being wrapped spirally around the core in alternatesuccessionwith and reversely of the threads of the other set,

said threads having been applied to said core when it was stretched to at least four times its normal length when uncovered, and said threads maintaining said core stretched to at least two times said normal length.

2. An elastic strand comprising a rubber core, an outer covering therefor, and a plm rality of threads inwardly of said covering and wrapped spirally around said core in alternately reversed directions, said threads having been applied to said core when it was stretched to at least four times its normal length when uncovered, and said threads maintaining said core stretched to at least two times said normal length.

3. An elastic strand comprising a rubber core, an outer covering therefor, and a plurality of threads inwardly of said covering and wrapped spirally around said core in alternately reversed directions, said threads having been applied to said core when it was stretched to at least four times its normal length when uncovered, and each convolution of each of said threads extending longitudinally of said core a distance less than the diameter of the core when the strand is in normal condition and preventing the return of the core to its normal length when uncovered and unstretched.

In testimony whereof I aflix my signature.

WILLIAM J. FOX.-

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