US2016168A

US2016168A - Elastic fabric

Info

Publication number: US2016168A
Application number: US1639A
Authority: US
Inventors: David M Clark
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-01-14
Filing date: 1935-01-14
Publication date: 1935-10-01
Anticipated expiration: 1952-10-01

Description

D. M. CLARK ELASTIC FABRIC Get. 1, 1935.

Filed Jan. 14, 1935 w 6 E :2 a j y p z AH IMWZ e ,J 7

Patented Oct. 1, 1935 UNITED STATES PATENT OFFICE aomm ELASTIC FABRIC I mm M. cm, mm, Mass.

Application January 14, 1935, Serial No. 1,639 *1 Claims. (01. 06-402).

threads between predetermined courses of the l knitted fabric, and stretch at right angles thereto is provided by knitting into said fabric one or more courses of elastic material. The elastic threads which are knitted in must be relatively fine in order to provide a garment relatively light 15 in weight and having a relatively smooth surface.

Such fabrics thus necessarily incorporate, in general, both a relatively fine elastic thread as small as or smaller than one-seventieth of an inch square in cross section which forms certain of the 20 knitted courses, and a relatively heavy elastic thread as large as or larger than one-sixtieth of an inch square in cross section which is laid in the fabric without being knitted therein. One of the principal objects of the present invention is to 25 provide a knitted fabric in which stretch in two directions at right angles to each other is provided by a single relatively heavy type of elastic thread so arranged in the fabric as to provide for a substantial stretch in both directions.

30 Elastic fabrics of this type are frequently used in supporting and confining garments, and the rubber incorporated in the elastic threads deteriorates as a result of the action of perspiration and atmospheric elements on the surface thereof.

35 The larger the cross sectional area of the rubber in the thread, the longer it will last without substantial deterioration, and a further object of the invention is accordingly to provide for the use of relatively large elastic threads in obtaining the 40 stretch in both directions without the necessity for using any relatively fine elastic threads, and without making the fabric too thick or rough on the surfaces thereof.

Where the elastic threads are laid into the usual fabric as it is knitted, there is nothing to hold said threads against sliding movement within the fabric as the result of a pull on said fabric lengthwise of the threads. Such fabrics cannot be cut 50 and successfully used thereafter without slipping of the elastic threads since-there is no way for positively securing the ends of the elastic threads, and breakage of an elastic thread, which allows sliding of said thread, materially reduces the 55 elastic characteristics of the fabric and also causes unsightly imperfections. A further object of the present invention is to provide for the securing of the several elastic threads within the fabric so that they will be held in proper position if they should break, and so that such fabrics may be cut in forming articles therefrom.

Other and further objects and advantages of the invention will more fully appear from the following detailed description taken in connection with the accompanying drawing, in which- 10 Fig. 1 is a diagrammatic view of a portion of the .fabric embodying the invention, said fabric being stretched substantially to the limit in both directions and being greatly enlarged.

Fig. 2 is an elevation of a garment incorporating the fabric of the invention. Like reference characters refer to like parts in the different figures.

The invention resides in so knitting the elastic threads into the fabric that stretch in both directions may be obtained with only a single elastic thread of relatively large size in proportion to the inelastic threads. Referring to Fig. 1, the, fabric, which can be knit on the well-known flat knitting machine, or on the circular dial and cylinder machine, or on certain other familiar types of knitting machines, is described as if it were knitted on a circular machine. Such a machine has a plurality of cylinder needles I and a plurality. of dial needles 2 arranged in staggered relation to the cylinder needles and extending at an angle thereto as in the usual circular machine. These machines form a tubular fabric, and each of the needles is individually controlled to determine the number of stitches and the type of knitting, as is well known.

. 'In the knitting of the fabric on a circular machine, threads 3, l, 5 and 6 respectively, are knitted successively during each complete rotation of the movable part of the machine. 40 Threads 1 and 8, which are the heavy elastic threads, are normally laid into the rows of knitting between successive courses without being directly knitted into the fabric, the thread being positioned between the loops formed by the cylinder needles and the loops formed by the dial needles. These elastic threads normally comprise filaments of rubber which have been wound with non-elastic threads of any suitable character, such as cotton, silk, or rayon. This windin Considering each thread separately, the thread 3 is knit by each of the dial needles, but each alternate cylinder needle performs no knitting operation on said thread so that the latter passes by each fourth loop in the preceding thread or course without being knitted into the fabric. Each alternate cylinder needle which does not form a loop in the thread 3 is, however, arranged and actuated so as to form a loop in the elastic thread I which engages with the loop in the preceding course, the elastic thread being engaged by the cylinder needle before the loops are formed in the thread 3. The thread 4 which forms the course following the thread 3 is knitted by each of the dial needles and also by each of the cylinder needles in the usual manner, the loops in said thread 4 engaging with the loops formed by the needles in the thread 3, with the exception, however, that where the cylinder needles fail to form loops in the thread 3 and instead form loops in the-elastic thread 1, the corresponding needle passes the loop 'ofthe thread 4 through the loop formed in the elastic thread. By the provision of the loops in the elastic thread it is possible to obtain a stretch for the fabric in two directionsat right angles to each other. It will be noted that the elastic thread I is normally positioned between the loops formed by the cylinder needles and the loop formed by thedial needles so that it is positioned between the twoouter-surfaces of the fabric.

The thread 5, which is inelastic, is knitted in the same manner as the thread 3 above described, with the exception, however, that the cylinder needles which form loops in the thread 3 do not form loops in the thread 5, thereby staggering the position of the loops in the elastic threads I and 8, as apparent from Fig. 2. The thread 8, as is clearly shown, is located between the cylinder and dial loops formed in the thread 4, except where it is engaged by the loops in the thread 6, which latter is knitted in the same manner as the thread 4 above described. It will be apparent that the loops in the elastic threads 1 and 8 need not of necessity be staggered, although the latter arrangement provides a slightly greater stretch parallel to the wales of knitting than when the loops are not staggered.

Since the thread 3 is not looped through each of the loops in the thread 6, it will be apparent that the threads 3 and I together form a complete course in the fabric. That is to say, where the thread 3 is not looped through the loops in the thread 6, the elastic thread I is looped therethrough and the fabric is accordingly continuous, with the threads 3 and I together forming a single course.

The thread 3 forms the course subsequent to the thread 6 and this thread is knitted in precisely the same manner as the thread 3 having loops formed therein by the same cylinder and dial needles, with each second cylinder needle omitting a stitch, said needle engaging instead with the elastic thread I which is located within the fabric in the same manner as the thread I, the cylinder needle engaging with the elastic thread I before engaging with the thread 3', as will be apparent. Where the needle engages with the elastic thread instead of with the inelastic,

thread a single yarn stitch is formed; the term single yarn indicating that both elastic and inelastic stitches are not formed together but that either the elastic or the inelastic thread is looped without incorporating a loop in the other thread on the same needle.

The arrangement shown in Fig. 1 represents the fabric as stretched substantially at a maximum in both directions, so that very definite loops are defined in the elastic threads I and 3. When the fabric is not stretched, however, after. 5 it has been knitted, the elastic threads, being much stiffer than the other threads, tend to become straight within the fabric, thereby drawing upwardly on the loops in the threads 4 and i to contract the fabric very substantially in 8. dll0 rection at right angles to the general direction of the elastic threads. By this straightening of the elastic threads, portions of the loops of the threads 6 are drawn into the base of the loops in the thread 4, so that a very emphatic contrac- 15 tion of the fabric takes place.

The fabric of this type is intended to be incorporated in any structure, such as body restraining members of which girdles are an example. As shown in Fig. 2, the girdle 3 is formed 20 of this material and has sufficient elasticity to conform to the portion of the anatomy encased therein. By varying'the tension on the elastic thread as it is positioned within the fabric during the knitting thereof, it is possible to con- 25 trol the diameter or width of the finished garment at different portions thereof without changing the number of needles in the knitting machine operating upon the fabric.

Since the threads 4 and 6 are wrapped around 30 the elastic threads I and 8 when the fabric is in an unstretched condition, these threads prevent sliding of the elastic thread through the fabric so that if an elastic thread should break,

its eifectiveness is not lost since the inelastic 35- threads will hold said elastic threads in proper position. Since the elastic threads can be held against longitudinal sliding movement within the fabric, it will be apparent that the fabric may be' provided with pockets or bulges that 40 can be confined to localized areas in the garment. These pockets or bulges are formed by placing the elastic within the fabric in predetermined areas at a low tension as compared to the tension applied to the rubber in the remainder of the garment. These pockets or bulges remain properly located within the fabric and can be positioned in any desired part thereof, as will be apparent.

Stretch in a direction at right angles to the normal direction of the elastic thread may be eliminated in certain portions of the garment where it is desired, by so controlling the cylinder needles I that in addition to forming loops in the elastic threads at intervals, said needles also form loops in the corresponding inelastic threads. That is to say, each alternate cylinder needle engages with the elastic thread I and forms a loop therein which extends through the previously formed loop in the thread 6'. The thread 3 is then knitted by the cylinder needle I instead of being omitted as in the showing of Fig. 1, the loop of the thread 3 passing through the loop in the elastic thread I. Subsequently, the same needle I loops the thread 4 through the loops formed in the thread 3. Thus in the rows or wales of knitting formed by the cylinder needles I, there is an additional stitch inserted,

instead of omitting the stitch asindicated in cular knitting machine, it will be apparent that the same structure may be incorporated in a fabric when the latter is knitted on other types of machines, and the invention is not intended to be limited to a fabric knit on any specific type of machine.

, From the foregoing, it will be apparent that the invention provides for the production of an elastic fabric which is capable of stretching inboth directions, but which incorporates only one relatively large type of elastic thread which is so positioned in the fabric as to provide not only for stretch in the direction in which said thread extends, but also in the direction at right angles thereto, this latter stretch being provided by knitting said elastic threadinto the fabric at spaced points therein. The stretch can be concentrated or minimized in localized parts of the fabric, since the threads are held against sliding movement in the fabric, and stretch in one direction may be eliminated in localized parts by the formation of the loops in the inelastic thread where stretch in; only one direction is desired. v

I claim: a

1. A knitted elastic fabric having stretchin two directions in which certain courses consist of inelastic thread and the remaining courses consist of elastic and inelastic thread, said elastic thread being knitted into certain wales of the fabric, and the inelastic thread being knitted only into the remaining wales in the same course.

2. A knitted elastic fabric having stretch in two directions in which certain courses consist of inelastic thread and the remaining courses consist of elastic and inelastic thread, said elastic thread being knitted into certain wales only of the fabric, and the inelastic thread being knitted into the remaining wales in the same course, stitches being omitted in said inelastic thread in certain of the wales ,where the elastic thread is knitted.

t -5 3. A knitted elastic fabric having stretch in 'consist of elastic and inelastic stitches, said elastic stitches being formed in certain wales only of the fabric and the inelastic stitches in the same course being omitted at least in certain of the wales where the elastic stitches are formed.

5. In the method of forming an elastic fabric the steps which comprise forming all 'of the stitches in certain of the courses of inelastic thread and forming the stitches of the remaining courses of elastic and inelastic thread, the

, stitches of the inelastic thread in said remain- I same course in certain of said spaced wales.

' 7,. A knitted elastic fabric having stretch in two directions, said fabric consisting mainly of inelastic stitches, elastic stitches being formed only in certain spaced wales in certain courses, 40 inelastic stitches being omitted where the elastic stitches are formed, the elastic stitches being formed of elasticthreads otherwise laid in the fabric.-

DAVID M. CLARK,