US2437735A

US2437735A - Method of and apparatus for separating knitted fabrics

Info

Publication number: US2437735A
Application number: US606899A
Authority: US
Inventors: James L Getaz
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-07-25
Filing date: 1945-07-25
Publication date: 1948-03-16
Anticipated expiration: 1965-03-16

Description

J. L. GETAZ March 16, 1948.

METHOD OF AND APPAiiATUS FOR SEPARATING KNITTED F ABRICS Filed July 25, 1945 3 Sheets-Sheet l March 16, 1948. GETAZ 2,437,735

METHOD OF AND APPARATUS FOR SEPARATING KNITTED FABRICS Filed July 25, 1945 5 Sheets-Sheet 2 [N V EN TOR.

arch 16, 1948. J. L- GETAZ 2,437,735

METHOD OF AND APPARATUS FOR SEPARATING KNITTED FABRICS Filed July 25, 1945 3 Sheets-Sheet (5 iii.

TATE.

Patented Mar. 16, 1948 NITD STATES PATENT 'GF-Fl'C-E METHODOF APPARArns Fort 'sii'PA- RATING KNITTED FABRICS This invention is related to the knitting of textile fabrics or articles of apparel. It is related especially to means and method of separating a continuous length of knitted fabric into 'u'nits which are made into finished articles such as hosiery, sweaters, etc. I

In many types of knitting, it is desirable to keep the knitted fabric under tension as it is drawn from the knitting needles. A tension of this kind may be applied by feeding the knitted fabric through rolls, or winding it on a shaft, or it may be applied by attaohing'aweight to the knitted fabric. This tension is necessar some types of knitting in order to make the stitches of the fabric shed properly over the heads of the needles. In other types of fabrics, this tension improves the quality of the fabric by making "a tighter stitch, which gives the fabric more elasticity. This tension is preferably a pned by feeding the knitted fabric through corrugated mus which are driven at the proper speed for keepin .the desired tension applied to the fabric as 'it is knitted. The fabric is delivered from these rolls in a continuous length which is then separated into units of the desired length for making articles of apparel, These units may be fashioned as they are knitted, as in hosiery, pockets are knitted for the heel and toe, and in sweaters the neck and arm holes may be'fashioned; also such units may contain different kinds of stitches which are suitable for different parts of the article of apparel.

In order to separate these units so that'the articles of apparel may be iiniforin in size ahd'the different kinds of stitches may be in their proper place in the finished article, it is desirable to perform the separation along a certain course of knitting- This may be done by Cutting the fabric with scissors, and this method is 'sornetiine's used for separating wristlets for the sleeves of sweaters and ribbed tops for hosiery. But it is difiicult to follow a certain course of knitted -fabrics in cutting, and when articles are separated in this way, the edges may be uneven. A better way of separating these units is to k'n'it at the points of separation a loose course wane *pull" thread which may be drawn'out by hand and leave the edges even. I

The pulling f the threads iil these loose courses requires time on the part of the operator of the knitting machine, and restricts the number of knitting machines which one person oper ate. The operator of a hosiery knitting machine may not have time to separate each ho'sees it comes from each one of the machines which he is operating. In such a case, he cannot inspect each hose and stop a, knitting fnachine as soon it becomes out of adjustiiient or hasa broken needle, and this may cause additional seconds.

It is the purpose of this intention to provide means for separating these units of knitted fabric automatically as they leave the knitting machine Without interfering with the tension on the fabric, which is useful in drawing the stitches from the knitting needles. It is also a purpose of this invention to inake this separation along one cburs'e of the knitted fabric so as to leave the edges of the fabric even. 133 means of this in}- Vehtion a kmtter'may able to operate a larger number or knitting machines and at the same time improve the quality of his work by being able to inspect each knitted lihit as soon "as It is completed. p

In this invention the rolls which ap'ply the terif sion to the knitted fabric operate in the usual manner, and the seperaudn occurs just after the point, at Whih -spalfatio'fi is to be made, p sses through these ions. In making the separation, use is made or a yarn which has certa'm charac- .teristic's which are difiiiit from the characteristics of the yarns which are used in the body of the fabri. Such a yarn is used in kriittihg "one or more courses at the point where the separation is to be made. and is lferfedfio 'hefeb elow as the separating yarn, Thisseparating yarn may be of several types whichihave the characteristic of a tensile strehgth'sl'litable for knitting tinder normal conditions, but when special conditions are applied, such as are described below. the strength of the "separating yarn is diminished or is reduced to nothing while the strength of the body yarn is not arrested.

The type of separating yarn to be used may be selected to suit the special conditions which maybe most conveniently applied for reducing its strength. One of the special conditions which may be used for this purpose is the 'appm cation 'of solvents, which will dissolve the separating yarn and not affect the body yarn. In this case. the separating arn may be made "of polyvinyl alcohol and water may be l'lsd as '8, solve'nt. v

The preferred 'method is to apply s eciei conditions by the control of temperature. In this case, the tem erature may be raised to a perm: at which the separating yarn b'Cofiis very soft or melts and the body yarn is not affected. For this pur bsethesepa'raun' yarn may be hiade from a base of Vinyl resin. A yarn they be inade of this material which has a good tensile strength at atmospheres tempefetures, but as the temperature is raised, this stingth'is reduced to treetically nothing at teniperatiiies which do not affect the body yarns. l stens yarn is used as a separating yar'n and thep'r'oper temperature is applied to the knitted fabric at the point of separation, the units of knitted'fabri'c come apart.

Where the term b'o'dy yarns is used in this ap plication it is intended to include yarns made-6f cotton, wool sllk, rayon, Celanese, nylon, rubber or other 'fibr's when are coninionly used textile fabrics. Whether the special conditions mentioned above, which are applied to produce separation include the use of a solvent or the control of temperature, the body yarns are not at:

fected by the special conditions. If control of temperature is used, a temperature of 180 degrees to 200 degrees F. is suitable to remove the separating yarn without affecting the bodyyarns. I

This invention is useful in the manufacture of- 1 -In-Fig; 1 is shown the frame I of a knitting machine with a stationary cylinder 2. Extending be various kinds of knitted articles and has special advantages in the manufacture of hosiery. In

the knitting of ribbed tops for hosiery, these may.

be knit under tension on a rib machine with one or more courses of separating yarn at the'end of each top. By applying heat to the fabric, the separating yarn is removed and the labor of separating these tops eliminated. In hosiery. which is decorated with vertical wrapped stripes, a tension is needed to obtain proper knitting of the wrap threads, and this tension is usually applied by feedingthe hose in continuous fabric through tensioning rolls and separating them by hand, or by knitting the hose separately and attaching a weight to the top of each hose before the knitting of the wrap stripe begins. By the use of this invention these hose may be knit in continuous length of fabric and separated automatically. Also in the knitting of ribbed hosiery, tension is applied by feeding the continuous fabric'through tensioning rolls and the hose are separated by hand. By the use of this invention, they are separated automatically; This automatic separation permits the knitter to operate more machines and to inspect his work more closely.

The uses mentioned above for this invention in the manufacture of hosiery are related especially to hosiery of medium and coarse gauge for children and men and anklets and sport hose for ladies. In making hosiery of very fine gauge, such as sheer lady's stocking, the stocking is fashioned by varying the length of the stitch, a tight stitch being desirable in the ankle and foot. This stitch maybe made tighter by applying tension to the fabric, especially if it isjknitted with a yarn like nylon, which has an appreciable amountof elasticity. By the use of this invention, tension may be applied to the ladys stocking as it is being knitted in continuous fabric and the stocking separated automatically. The use of tension improves the fabric of the lady's stocking, and the automatic separation permits the knitter to oper ate the same number of machines as though'the stockings were knit separately. In knitting ladies stockings with an automatic welt, one or low the cylinder is a chain 3 which is driven by the drivingshaft 0f the knitting machine by a mechanism which is not shown. Yarns are fed to the cylinder 2 with suitable yarn feeding devices such as are commonly used with means for more courses of separating yarn is knitted at the end of the looper heading, then the knitting yarn is changed to a body yarn before the stitches of alternate needles are held by the dial bits; 'The tensioning device is inoperative during the knitting of the welt, and tension is applied after the stitches have been transferred from the dial bits to the knitting needles and knitting is begun below the welt. As the welt passes below the ten'- sioning rolls, heat is applied to the fabric contain ing the courses of separating yarn and the looper heading of the stocking below is separated from the welt of the stocking above. Means for making this separation automatic without interfering with the tension'are shown in the following drawings:

Fig. 1 is an elevation of a knitting machine embodying this invention.

Fig. 2 shows a piece of knitted fabric which is knitted according to the methodjof this invention. Fig,- 3 is a, detailed view of the mechanism shown in Fig. 1.

changing from one knitting yarn to another.

In Fig. Zare shown courses of fabric I00 which contain the body yarn [M in certain courses which comprise the body of the fabric, and the separating yarn I02 in those courses at which it is desired that the fabric be separated.

The chain 3 drives a sprocket wheel 4, as shown in Figures 3 and 4, which is mounted on a shaft 6, which turns in bearings in plates I and 8, and these are mounted on the frame I by arms 9 and I0. On shaft 6 between plates 1 and 8 is a roll I I, and on the end of shaft 8 outside plate 8 i a gear wheel I2. Meshed with gear wheel I2 is a gear wheel I3 mounted on shaft I4, which is parallel to shaft 6 and on shaft I4 is a roll I5. The bearings I8 of shaft I4 slide in grooves I! in plates I and 8 and springs I8 press against bearings I8. which causes roll I5 to press against roll I I.

On shaft 6 is a sprocket wheel I9 driving a chain 20 and sprocket wheel 2I on shaft 22. Shaft 22 turns in hearings in plates 1 and 8, and on this shaft 22 between plates 1 and 8 is a roll 23, and on the end of shaft 22 outside of plate 8 is a gear wheel 24. Meshed with gear wheel 24 is a. gear wheel 25 mounted on shaft 28, which is parallel to shaft 22, and on shaft 26 is a. roll 21. The bearings 28 of shaft 26 slide in grooves 20 in plates I and 8 and springs 30 press against bearings 28, which causes roll 21 to press against roll 23.

Rolls

23 and 21 are hollow and inside of each roll is a resistance element 3| Shafts 22 and 26 are hollow and extending through these shafts are stationary tubes 32, and through these tubes 32, the electric leads 33 and 34 are connected to resistance elements 3|. On the ends of tubes 32 are regulators 35 for controlling the temperature produced by resistance elements 3|.

On shaft 6 is a pulley 38 driving a belt 31 and pulley 38 on shaft 39. Shaft 39 turns in bear ings in plates I and 8, and on this shaft 39 between plates I and 8 is a roll 40, and on the end of shaft 39 outside of plate 8 is a gear wheel 4I. Meshed with gear wheel M is a gear wheel 42 mounted on shaft 43, which is parallel to shaft 39, and on shaft 43 is a roll 44. The bearings 45 of shaft 43 slide in grooves 46 in plates 1 and 8 and springs 41 press against bearings 45, which cause roll 44 to press against roll 40. The belt 31 which drives pulley 38 is a loose belt and pressing against belt 31 is an idler pulley 48 mounted on an arm 49. Arm 49 turns on a pin 50 on stud 5| fastened to plate I; pressing against arm 49 is a spring 52 with adjustment screw 53, supported by projection 54 from plate I.

The operation of the above mechanism is as follows:

by the knitting needles. The

rolls

23 and 21 are driven at practically the same peripheral speed as rolls H and 15. The fabric I00, after being drawn under tension between rolls II and I5, passes between

rolls

23 and 21, where it is heated by the heat from resistance elements 3| which heat the

rolls

23 and 21. This heating is controlled by regulators 35 so that the temperature of

rolls

23 and 2? does not exceed a iven temperature, such as 200 degrees. This temperature is sufhcient to melt or greatly reduce the tensile strength of yarn I22 without affecting yarns ml, which causes the fabric to separate.

The roils 4d and 44 and the mechanism which drives these rolls are not a necessary part of this invention, but are useful in separating the fabric should there be some threads which cause the units of fabric to hang together. If the rolls t0 and i i are free to turn as driven by belt 37, their peripheral speed is slightly greater than that of

rolls

23 and 21, and rolls H and I5, so that when the fabric is separated by the heat of

rolls

23 and 21, the action of rolls 40 and 44 pulls the lower unit of fabric IEO away from the unit above. Before the fabric 199 is separated as it comes through the rolls, the rolls 4!! and 44 apply some additional tension to the fabric and the belt 3'! slips so that the peripheral speed of rolls 48 and 34 is the same as that of the rolls above, until the fabric is separated.

After an article has been thus separated from the length of fabric and as the fabric continues to issue from the machine, its foreshortened end gravitates between and is engaged by the rotating lower rolls 40 and 44 and the separating operation is repeated.

While the above description is for knitting machines with stationary cylinders, this invention applies also to machines with rotating cylinders in which the mechanism above mentioned containing the rolls rotates with a cylinder.

Iclaim:

1. The method of manufacturing knitted articles which includes knitting in a continuous length of fabric a series of articles of body yarn with at least one course of a separating yarn therebetween, said separating yarn having reduced tensile strength under certain conditions which do not adversely affect said body yarn, and, as said length of fabric issues from said knitting point, applying said conditions to weaken said separating yarn and tension to separate said articles.

2. The method of manufacturing knitted articles which comprises knitting in a continuous length of fabric a series of articles of body yarn with at least one course of a separating yarn therebetween, said separating yarn having reduced tensile strength under certain conditions which do not adversely affect said body yarn, applying tension along successive portions of said length of fabric as it issues from the knitting point, and applying said conditions to the portion of said length of fabric under tension, whereby to separate saidarticles.

3. The method of manufacturing knitted articles which includes knitting in a continuous length of fabric a series of articles of body yarn with at least one course of a separating yarn therebetween, said separating yarn having reduced tensile strength at a higher temperature at which said body yarn is not adversely affected, and, as said length of fabric issues from said knitting point, applying heat to weaken said 6 separating yarn and tension to separate said articles.

4. The method of manufacturing knitted articles which includes knitting in a continuous length of fabric a series of articles of body yarn with at least one course of a separating yarn therebetween, said separating yarn having reduced tensile strength at a higher temperature at which said body yarn is not adversely affected, applying tension to successive portions of said length of fabric as it issues from the knitting point, and applying heat to the portion of said length of fabric under tension, whereby to separate said articles.

5. In a knitting machine of the type adaptable to produce a series of knitted articles in a continuous length of fabric with at least one course or a separating yarn therebetween, said separating yarn having reduced tensile strength under certain conditions which do not adversely affect the yarn of said articles, the combination with said machine of means for separating said arti-- cles, said means comprising a first pair of rotating rollers adapted to frictionally engage said length of fabric as it issues from the knitting point, a second pair of rotating rollers adapted to frictionally engage said length of fabric at a point spaced from said first pair of rollers, said second pair of rollers tending to rotate at a peripheral speed slightly greater than that of said first pair of rollers, whereby to apply tension to the portion of said length of fabric between said first and second pairs of rollers, and means to apply said conditions to the portion of said length of fabric under tension.

6. In a knitting machine of the type adaptable to produce a series of knitted articles in a continuous length of fabric with at least one course of a separating yarn therebetween, said separating yarn having reduced tensile strength at a higher temperature at which the yarn of said articles is not adversely affected, the combination with said machine of means for separating said articles, said means comprising a first pair of rotating rollers adapted to frictionally engage said length of fabric as it issues from the knitting point, a second pair of rotating rollers adapted to frictionally engage said length of fabric at a point spaced from said first pair of rollers, said second pair of rollers tending to rotate at a peripheral speed slightly greater than that of said first pair of rollers, whereby to apply tension to the portion of said length of fabric between said first and second pairs of rollers, and a heating surface adapted to contact said portion of said length of fabric.

JAMES L. GETAZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,039,989 Morley Oct. 1, 1912 1,103,922 Adamee July 14, 1914 1,285,098 Fisher Nov. 19, 1918 1,665,230 Spalding Apr. 10, 1928 1,785,665 Hofner May 13, 1930 1,837,616 Greenwald Dec. 22, 1931 2,297,881 Fuller Oct. 6, 1942 2,314,618 Green Mar. 23, 1943 2,331,955 Beebe Oct. 19, 1943 2,346,195 Spalding Apr. 11, 1944