US3068676A

US3068676A - Warp knitted fabric

Info

Publication number: US3068676A
Application number: US713879A
Authority: US
Inventors: Bolton Wilfred
Original assignee: A W SWANN AND Co Ltd
Current assignee: A W SWANN AND Co Ltd
Priority date: 1957-02-11
Filing date: 1958-02-07
Publication date: 1962-12-18
Anticipated expiration: 1979-12-18
Also published as: US3063272A; FR1198750A; CH346962A

Description

1962 w. BOLTON 3,068,676

WARP KNITTED FABRIC Filed Feb. 7, 1958 3 Sheets-Sheet 1 w w w Off. :64 p400 INVi/VTQR NIL-FRED BOLTON ATTMIVE) Dec. 18, 1962 w. BOLTON WARP KNITTED FABRIC Filed Feb. 7, 1958 3 Sheets-Sheet 2 V M/VE/VTOR WTLFRED BOLTON 6 A BY 1 0%. W ami ATTO Dec. 18, 1962 w. BOLTON WARP KNITTED FABRIC 3 Sheets-Sheet 3 Filed Feb. 7, 1958 A TTo/a/ve Unite Stats Patent Ohtice 3,068,676 Patented Dec. 18, 1962 This invention appertains to warp knitted fabrics, that is to say fabric comprising chains or wales of ordinarily meshed knitted loops which are formed from individual threads or ends and are connected laterally.

Moreover, the invention is concerned with close warp knitted fabric, that is to say, fabric produced with a full set of threads, i.e. with one thread to each needle, and the loops are joined sideways at at least every alternate course. The invention is applicable not only to wholly close warp knitted fabrics, but to portions of close warp knitted fabric incorporated in other types of fabric.

Broadly speaking, then, the invention is applicable principally to close fabrics such as those having plain laps, ribbed laps, knock-off laps and crepe or knop laps, but also in suitable cases may be applied to open fabrics exemplified by pillar or chain nets, lace nets, gimped or inlaid nets and satin nets.

The primary object of the present invention is to provide, in warp knitted fabrics, novel patterning effects whereby a new range of pleasing patterns and designs of practically infinite scope and variety can be produced in a simple manner resulting also in unorthodox texture of the fabric.

Now faults caused in Warp knitted fabrics by normally undesired interference with, or interruption of, the controlled run-in of the warp ends, during knitting, are very noticeable both on the back and the face of the fabric, irrespective of the lapping movements of the thread guides employed. The effects of faulty warp knitting are all the more pronounced when yarn such as nylon is being knitted which yarn, besides being immensely strong, is capable of considerable stretch and of full and immediate recovery. Such faults, moreover, are very prominent when warp knitted fabrics, by virtue of being knitted with yarns of fine deniers have a tendency to transparency.

Thus, for instance, there is the fault caused by dragging thread and revealed, in the case of a 1 x 1 lap tricot, as an apparent joining or running together of the two needle wales concerned in the making of the laps; This appearance is due to the fact that loops in these particular needle wales are formed with ends under a greater tension than the ends used in forming surrounding loops. All the needle loops in the area of the fault are affected, and the prominence of the fault depends, of course, on the amount of tension to which the appropriate ends are subjected during the dragging period. In any event, there is a marked contrast between the tightened loops of a dragging thread fault and the surrounding loops formed under normal conditions long before the breaking point of the tensioned ends is reached.

A second fault is one caused by slackening of warp ends resulting in snarling of the slackened ends which latter bubble through the ground structure.

As will be appreciated the faults referred to are normally rare owing to modern warp knitting methods, good quality yarns and the efiicient use of skilled labour.

An aim of the present invention, however, is deliberately to cause such faults in a controlled manner, and in predetermined sequences, resulting in the aforementioned patterns and designs. In short, the invention is based upon the judicious exploitation of known knitting faults.

The improved warp knitted fabric constituting this invention is accordingly patterned by effects, hereinafter for convenience referred to as concentrations of tightened loops, produced by interference with, or interruption of, the controlled run-in of selected warp ends, during knitting of the fabric.

According to a feature of the invention there is provided a warp knitted fabric which is patterned by desired dispositions of concentrations of tightened loops produced by reducing the normal rate of run-in of, and thereby tensioning or dragging, selected ends suchwise as to cause needle wales to have the appearance of running together over predetermined courses as hereinbefore described.

In accordance with another feature, there is provided a warp knitted fabric which is patterned by desired disposition of concentrations or" tightened loops produced by increasing the normal rate of run-in of, and thereby slackening, selected ends suchwise as to cause snarling of those ends and bubbling of the latter through the ground structure.

Or, one and the same piece of Warp knitted fabric may incorporate concentrations of tightened loops of the two kinds, viz. those produced both by tensioning or dragging, and slackening of predetermined ends.

Considered from its broadest aspect, the overall method producing a patterned warp knitted fabric of the gen' erally improved character therefore consists in maintain ing, throughout their length, a calculated run-in of appropriate warp ends suchwise as to produce a ground of standard (normal) structure, and interfering with, or interrupting, the controlled run-in of each of selected ends during the knitting of predetermined courses so as to produce concentrations of tightened loops but permitting the selected ends to run-in normally during the knitting of the remaining courses of the fabric. Thus, in the intervening periods between the periods of its abnormal run-in each selected end is allowed to resume its normal controlled run-in.

For producing concentrations of tightened loops of the dragging thread type, the normal rate of run-in of said selected ends is reduced to apply tension to the latter, whereas to produce concentrations of the second type hereinbefore described the normal rate of run-in of selected ends is increased to slacken the same.

Broadly considered, the means provided in conjunction with a warp loom for interfering with or interrupting the controlled run-in of selected warp ends may conveniently comprise, in combination, at least one row of individual and suitably guided warp end interfering members, one to each of predetermined ends or groups of ends in a series of ends threaded through the guides of a guide bar, relatively stationary tension elements adjacent to which the ends run, said elements being arranged at opposite sides of, and adapted to co-operate with, the interfering members, selectively operable actuating members each connected with some of the interfering members and adapted, when moved selectively in one sense, to raise or lower selected interfering members and so cause them to engage and lift or lower portions of the corresponding ends or groups of ends extending between the tension elements but when moved in the reverse sense to respectively lower or raise the elevated or lowered members and so return the relevant ends or groups of ends to their normal path and patterning mechanism for controlling the ac tuating members.

Conveniently, the warp end interfering, i.e. lifting or lowering members may be vertically movablein which instance the actuating members may consist of horizontally shiftable rods or the like which are connected with the interfering members by flexible elements passing over grooved pulleys or equivalent. In any event, warp end 3 interfering members of the row are each adapted to engage a group of, say, two, three or four selected ends.

In order that the invention may be more clearly understood and readily carried into practical effect, specific examples of warp knitted fabrics produced on a two bar warp loom and patterned by concentrations of tightened loops, will now be described with reference to the accompanying drawings, wherein,

FIGURE 1 illustrates, on a greatly magnified scale, the back of a portion of plain, single bar 1 X 1 warp knitted fabric incorporating a concentration of tightened loops produced by tensioning or dragging selected ends,

FIGURE 2 depicts, on a much smaller scale and for purpose of comparison, adjoining portions of single bar and double bar fabric both patterned by concentrations of tightened loops produced by dragging selected pairs moreover, has normally straight prominent wales W and the crossings of the warp ends resulting from the manner of lapping are indicated at c. The two adjoining wales W and W5 are involved in the concentration of tightened loops fs these wales, as a consequence of a single warp end being lifted and tensioned, having the appearance of ends in predetermined wales and over desired courses, 1

FIG. 3 is a diagrammatic representation of a portion of tricot fabric having double or plated knitted loops and showing a concentration of loops involving two wales which are distorted towards one another and produced by tensioning or dragging a single warp thread or end,

FiZGURE 4 illustrates a portion of 1 X 1 tricot combining concentrations of tightened loops produced in accordance with this invention with conventional patterning, as will be hereinafter described.

The portion of plain 1 x 1 fabric F shown in FIGURE 1 is produced on the single set of needles of a double bar loom co-operating with the front bar only of the latter. As, will be seen, the illustrated portion of fabric F incorporates a concentration of tightened loops is which involves three adjoining wales W W2, and W3 and is produced by lifting and thereby tensioning or dragging two adjacent warp ends. The normal rate of run-in of these two ends is, therefore, reduced and the result is to drag and bunch knitted loops together into a knot adjacent to which small. openings 0 occur. FIGURE 1 accordingly depicts a typical concentration of tightened loops produced by dragging Warp ends and distorting loops in a single bar fabric.

In FIGURE 2 a much more extensive portion of such single-bar fabric is indicatedat F, this portion being patterned by predetermined dispositions and sequences of concentrations of tightened loops fs of the character described in the last preceding paragraph, and being adjoined by a .portion of two-bar fabric F patterned by other sequences of more tightly formed concentrations of tightened loops fs Thus, in making. the portion of two-bar fabric F the back guide barris only half set, i.e. with warp ends threaded through alternate ones only of the thread guides of the said bar, the latter being shogged suchwise as to produce 2 x l lapping. The front bar, on the other hand, is fully set or all in, i.e. with warp ends threaded through all of the guides in the bar and the latter is actuated to produce 1 x1 tricot lapping. Of the series of warp ends threaded through the front guide bar alternate pairs of these ends are permitted to run-in normally, whilst the intervening pairs are lifted to produce the desired sequences of concentrations of tightened loops fs by the dragging thread technique. Although for convenience of illustration in FIGURE 2 a portion of single bar fabric is shown actually adjoined to a portion of double-bar fabric it would usually be the intention (without limitation in this respect) to produce such fabrics separately.

FIGURE 3 illustrates the incorporation of a concentration of tightened loops is in a true singletricot fabric F that is to say double 1 1 warp knitted fabric made on one set of needles'co-operating with two fully set guide bars each making similar laps but in opposite directions. ones in plated relation. Thus, it will be realised that the un-shaded knitted loops l at the back of the fabric of joining or running together at d. In practice, the tightened and distorted knitted loops in the area d contrast markedly with surrounding normal loops.

Front bar loops such as l which, due to their positions on the needle stems when lapping, normally plate on the face of the fabric as shown in FIGURE 3 tend to be distorted at the times when concentrations of tightened loops such as fs are being formed. No such disturbance is, in fact, shown in FIGURE 3 as it may not always and does not inevitably occur. But where conditions are such that disturbance of the plating relationship of face ioops l with respect to loops 1 of the back Warp ends is likely to occur then the relative displacement of the front and back loops may be relied on to produce two-tone efiects when using contrastingly coloured front and back warp ends. But to ensure that the disturbed plating is uniform throughout the width of the fabric, appropriate adjustment of the needle bar and other machine settings may be required.

In the warp fabric illustrated in FIGURE 4 a ground structure or background F of l X 1 tricot produced by the co-operation of two fully set guide bars with a single set of needles, is ornamented by the combination of conventional patterning f with concentrations of tightened loops rfs produced in accordance with this invention. The patterning f in this case consists of horizontal stripes produced by varying the lapping of the front guide bar: thus, throughout the courses over which each of the stripes extends the laps on the front bar are changed from 1 X l to 2 X l or even 3 X 1. Alternate pairs of the warp ends extending through the said front bar are liftable selectively to tension or drag these ends andso produce the concentrations of tightened loops fs instead of being in the form of stripes, however, the conventional patterning may consist of diamonds, squares or any other appropriate geometrical designs.

Each concentration of tightened loops can extend, walewise, over any appropriate number of courses and although the invention is by no means limited in this regard it may be mentioned that concentrations extending over anything from, say, eight to twelve or more courses are usually sufficiently bold for the purpose in view. As will be realised, moreover, concentrations of tightened loops can be produced in predetermined wales and over any desired courses--either in selected areas, or throughout the full width of the fabric. Accordingly, the patterning scope is almost unlimited and practically infinitely variable. For example, the concentrations of tightened loops may be so disposed in the improved fabric as to provide floral type designs, all-over effects, mock intarsia patterns, and various geometrical designs including those based on vertical or/ and horizontal stripes or/and blocks, diamonds and the like. Designs such as are adopted in lace and embroidery work can also be freely used. a

The number of initially separate warp ends incorporated in each concentration of tightened loops may also vary in which regard the lapping movements imparted to the ends during the knitting of the fabric are an important factor contributing to the ultimate results. It is,

' however, found that to be of a bold and outstanding tip In such fabric the knitted loops are double lie behind and are hidden by the shaded knitted loops pearance a concentration should normally be at least two needle wales in width. For instance, in a 1 X 1 lap tricot ground structure, and notwithstanding what is shown in FIGURE 3, concentrations of tightened loops each involving three needle wales are considered to be most satisfactory, and such effects may conveniently be produced by adopting a warp end set-out wherein spaced pairs of ends are selected to have their controlled run-in interfered with or interrupted while intervening pairs of ends are permitted to run-in normally. Theoretically, of course, the larger the number of ends used in producing the concentration of tightened loops, the greater will be the contrast between these concentrations and surrounding loops, but, in practice, and to provide for maximum patterning scope, it is found that selected ends interfered with or int rrupted in pairs, or in small groups of three or tour, will satisfactorily cover most effects and lapping systems.

it is to be noted, moreover, that when producing concentrations of tightened loops by deliberate and judicious tensioning or dragging of selected ends, recovery of normal run-in of the said ends, after controlled reduction of the normal rate of such run-in, tends to form slack loops which are visible on the face and back of the fabric. Slack loops formed in this way are not, however, detrimental and in some instances may enhance the design by virtue of producing shadow effect. 7

The depth, i.e. the walewise extent, of a complete pattern or design constituting dispositions of concentrations of tightened loops as herein defined, may also vary widely according to requirements.

I claim:

1. A close Warp-knitted fabric comprising a plurality of warp ends knitted into wales of generally uniformly knitted loops, said wales being interconnected by weftwise-extending lapped portions of said Warp ends, said fabric having at each of predetermined points therein a concentration of tightened and distorted selected ones of said knitted loops, said concentrations of loops constituting patterning configurations contrasting with the uniform non-tightened and non-distorted knitted loops.

2. A close warp-knitted fabric as claimed in claim 1,

wherein each of the said concentrations of knitted loops is in the form of a knop of said loops which are smaller and tighter than adjacent normal knitted loops.

3. A double 1 x 1 close warp knitted fabric comprising front and back sets of similarly but oppositely lapped Warp ends knitted into wales of generally uniformly knitted double loops in plated relation, said fabric having at each of pro-determined points therein a concentration of tightened and distorted ones of said knitted loops in two adjacent wales, whereby said wales have the appearance of running or joining together over a plurality of courses, other ones of said knitted loops being slack loops forming openings adjacent to each of said concentrations of loops.

4. A close warp knitted fabric as claimed in claim 3 wherein each of said concentrations of loops is at least two wales in width and extends over at least eight successive courses.

References Cited in the file of this patent UNITED STATES PATENTS 1,201,803 Chace Oct. 17, 1916 1,482,705 Serra Feb. 5, 1924 2,015,818 Schonfeld Oct. 1, 1935 2,030,459 Meinig Feb. 11, 1936 2,190,560 Gaines Feb. 13, 1940 2,249,342 A1111 July 15, 1941 2,263,787 Safierson Nov. 25, 1941 2,289,302 Bradshaw July 7, 1942 2,396,525 Newman Mar. 12, 1946 2,476,153 Little et a1. July 12, 1949 2,531,718 Rice Nov. 28, 1950 2,608,079 Slater Aug-26, 1952 2,718,132 Herrnstadt Sept. 20, 1955