US2913890A

US2913890A - Yarn change end attachment for circular knitting machines

Info

Publication number: US2913890A
Application number: US610966A
Authority: US
Inventors: Frank R Page
Original assignee: Scott and Williams Inc
Current assignee: Scott and Williams Inc
Priority date: 1956-09-20
Filing date: 1956-09-20
Publication date: 1959-11-24
Anticipated expiration: 1976-11-24

Description

Nov. 24, 1959 F, R PAGE 2,913,890

YARN CHANGE END ATTACHMENT F'OR CIRCULAR KNITTING MACHINES Filed Sept. 20, 1956 United States PtentfO YARN CHANGE END ATTACHMENTEOR CIRCULAR KNIrrmG MACHINES- g Frank R. Page, Laconia', NH., assgnor to Scott & lWil-1 liams, Incorporated, Laconia, N.H., a corporation of Massachusetts Application september zo, 1956, serial No. 610,966

s Claims. (Cite-125) This invention relates to a yarn change endl attachment for circular knitting machines `and incre particularly to an attachment to prevent yarn change ends from being knit in. In circular knitting machines trouble is someencountered lwhen changing yarns, due toyarn change ends being caught and incorporated in the fabric. Diiculty of this kind is found on machines making ladies seamless hosiery, such for example as the Scott &\Williams model K machine shown in theR. W. Scott Patent No. 1,282,958. When a yarn change end becomescaught in the needles, the result may be an overloaded conditionI in the fabric causing cut stitches, a oa'tedyarn extend'- ing between two points in the fabric, and'rffend "of yarn showing on the outside of the stocking or, in cases where colored yarns are used, a few stitches showing-the wrong color. Any of these occurrences may result in ythe stocking being classed as other thanrst quality. Infsome cases where relatively expensive yarns are used, it 'is the practice, wherever possible, to remove the caught ,end

manually. This is a rather costly operation.` The con- It is the object of the lpresent invention `to prevent Patented vNov. 24, 1959 and dial, and carries the yarn change ends away witlr out affecting the fabric or lthe knitting operation.

lThe invention is shown embodied in the Scott & Williams model K machine of the Scott patent above referred to. Referring to the drawings, there is the usual revolving needle cylinder 260 with independent needles N moving vertically therein. Outside the upper end of the cylinder is `the usual sinker cam ring 300 to move the sinkers S. y

Yarns Y are fed to the needles over a throat plate 560 by yarn fingers F. The yarn fingers are moved out of action and into action by thrust rods 461 controlled from the usual main pattern drum (not shown). T'he lingers are pivoted, as usual.

There is `the usual dial D located just above the upper end of the cylinder land containing the usual transfer bits T for use in connection with making a turned welt. The dial D is rotated in synchronism with the, needle cylinder by the usual means,'including bevel pinions 16, 17 in- `dicated in Fig. 1. The spindle bevel pinion 17 is tight on a vertical spindle 18 which supports and rotates the right of center in Fig. l, illustration of the clamp having been omitted.

yarn change ends from becoming knit in. It ischaracter-- istie of the invention that means'are provided tolfpyull the yarn change ends away from the needles out of harrns way by air suction applied all around the needle circle.

In the drawings, Fig. 1 is a vertical view largely in section through the head of a Scott & Williams circular" machine for making ladies hosiery, showing theynew attachment,`

the section being taken from rear to front'of .the machine. Fig. 2 is a diagrammatic view ofl the upper end of` the cylinder and the dial of the machine'of Fig. l, showing how the suction is obtained andthe position offayarnV change end before and after 4the suction ow of tlieinven# tion is applied. Y 4 i, l

Fig. 3` is a view in detail of part of the delayed action means to shut off the airsupply after a yarn change.

The difficulty with yarn change ends extendingl from the needles, or those which due to improper clamp and cutter action are unattached, is that they get caught in the needles and fabric. This is particularly apt to occur in circular machines having plates such as dials above the needle cylinder. These dials carry knitting instrumentalities such as transfer bits or two part needles. Jets of compressed air have heretofore been directed against the needles or fabric at one point on the needle circle to control the yarn ends, but I have found that loose yarn ends can be handled more satisfactorily by a gentle vacuum or suction flow applied all around the periphery of the needle circle from the inside. To obtain this, the compressed air which may be available on the machine 'or from another source is used to inducea functional air ow. The compressed air is shown led down through the center of the dial and directed downwardly in a concentrated blast in a position axially central of the needle cylinder. This remote control creates a gentle the needle circle where they cannotl accidentally cross@ the needle `path to possibly be seized cause one lof` To open and close the shears the following parts are provided. Connected to the back end of the upper blade l22 is a wire 23 extending upwardly to a yarn shears operating lever Z4. This lever extends toward the rear and is pivoted on the main dial bracket 20. The lever has a rear extension overlying one of the thrust rods 461. During each yarn change when the thrust rodridesv up on a cam on the main pattern drum the operating lever turns about pivot 25 and the shears open. thrust rod 461 drops oif the drum cam the shears close I and any yarn taken out of action will be clamped and cut off. Such a yarn change results in two orV more free ends of yarn extending from the needles, i.e. those of the yarn introduced and the yarn removed, which ends normally lie somewhere above the dial cap 19 .at n various positions, one of which may be similar to that in Fig. 2 marked Yarn end before air is applied. The problem is how to get such ends under the dial away, from the defects previously mentioned.

In accordance with the illustrated embodiment of the invention, there is an axially central hole 27 in the dial spindle 18 (see Figs. 1 and 2). When compressed air is forced into the upper end of the hole it is discharged from the bottom of the dial into the center of the needle cylinder in the form of a jet or blast in a downward direction. The effect of this blast is to draw a mild flow of air into the needle cylinder all around the needle circle.

It is found that this creates sufficient down draft to draw the loose yarn ends down and to locate them substantially in the position in Fig. 2 marked Yarn end after air is applied, where, after the draft of air ceases, they will not rise to become entangled with the needles.

The parts of the attachment which serve to start the air ilow and stop it after a short delay are as follows. Above the bevel pinons 16, 17 is a cover 28 carried by the main dial bracket 20. Corning to the upper part of this pinion'cover is a compressed air line 29. This leads to an air valve 30 carried by a small bracket 3],

fastened on the pinion cover. The air line 29 continues through the valve 30 and down to the upper end of the vertical hole 27 in the dial spindle 18 (see Fig. 1). In the valve 30 is a shut-oit valve stem 32 for the valve. This stem 32 extends downwardly from the valve to a stud 33 mounted on the end of the yarn shears operating lever 24. The stem passes freely through a hole in the stud and extends a short distance below the stud. There is a collar 34 on the stern just below the stud. On the stern, just above the stud, is a compression spring 35. The upper end of the spring is held at a lixed point on the stem by a collar 36.

When the shears operating lever 24 opens the shears it moves the stud 33 downwardly against the collar 34 on the valve stem. The downward movement of the valve stem opens the valve 30 and the blast of air begins to come out of the hole 27 in the lower end of the dial spindle 18.

In closing the shears to cut the yarn just taken out of action, lever 24 is released and the air would normally be shut oli at the same time, but since one of the free ends of yarn is not present until this action occurs, it is necessary to temporarily delay closing the valve.

For the purpose of holding the valve open and tripping it closed later, the following parts are provided. There is a horizontal trip lever 37 carried on an extension of the pinion cover 28. This lever pivots about a vertical axis intermediate the ends of the lever. As seen in Fig. 3, one end 38 of the lever lies near the valve stern 32 at such a level that when the stem is depressed by the shears operating lever, this end 33 of the trip lever lies at a leveljust above the collar 36 on the stem. Near the opposite end 39 ofthe lever is a tension spring 40 connecting `that end to the small bracket 31. When the valve stem is depressed and the valve open, this tension sp'ning pulls the end 38 of the trip lever over on top of the col-lar 36 and holds the valve open. Thus the valve stays open for a partial revolution of the needlecylinder after thel yarns are cut.

To close the valve there is a tripping pin 41 extending upwardly from the spindle driving bevel pinion 17. This fpin 41 is so positioned as to move the inner end 39 of the trip lever 37 outwardly once every revolution of the needle cylinder. This releases the collar 36 and the compression spring 35 pushes the stem 32 up and closes the valve 30.

It will be observed that no additional space on the main pattern drum is needed to operate the attachment for disposing of yarn change ends. The attachment causes an inward vacuum flow all around the space between the dial and cylinder suicient to draw in the yarn change ends before the vacuum is shut olf but not violent enough to disturb the knitting operation. It is particularly-useful during the making of heels andtoes, as yarn ends not carried below the dial are quite likely to enter the needle circle during reciprocatory knitting.

In machines not equipped with la dial and dial cap there isV usually present a corresponding plate, on which are mounted the yarn clamp and shears, and between such as plate and the top of the needle cylinder the flow of air to lower free ends of yarn may be created as described.

What is claimed is:

1. In a circular knitting machine, a needle cylinder, a dial above the cylinder, cooperating knitting instrumentalities in the dial and cylinder and an air supply 011 the machine, in combination with a vertical spindle supporting the dial and having an opening therein con- /nected to the air supply adapted to produce a downward blast of air axially central of, and within the cylinder, whereby a gentle ow of air is induced around the needle circle adapted to draw any yarn change ends inside the needle cylinder away from the needles.

2. In a circular knitting machine, a needle cylinder, knitting instrumentalities therein, a dial above the cylinder, yknitting instrumentalities therein, at least two movable yarn fingers to feed yarn to the instrumentalities, and yarn shears adapted to cut olf yarn from ngers moved out of action, in combination with an air supply above the dial adapted to produce an axially central downward blast of air from the under side of the dial, whereby a gentle W of air is induced around and insi'de the needle circle adapted to draw any yarn change ends inside the needle cylinder and away from the knitting instrumentalities.

3. In a circular knitting machine, a revolving needle cylinder and ya revolving dial above the sylinder, knittingl instrumentalities in both dial and cylinder, at least two pivoted yarn ngers to feed yarn to the instrumentalities, yarn shears to cut yarn from ngers pivoted out of action, and an air supply and a valve associated with the dial adapted to produce a downward blast of air centrally from the under side of the dial, in combination with means adapted simultaneously to raise a yarn nger out of action, operate the shears and open the air valve; whereby a temporary vacuum flow is produced all around the needle circle adapted to draw any yarn change ends down inside the needle cylinder away from the instrumentalities.

References Cited in the le of this patent UNITED STATES PATENTS 2,275,276 Williams MaI. 3, 1942 2,405,162 Nyhuis Aug. 6, 1946 2,424,033 Hilker et al. July 15, 1947 2,582,092 Ancet Jan. 8, 1952 2,636,364 Moss Apr. 281953 2,713,353 Casati et al. July 19, 1955 2,844,952 Wawzonek July 29, 1958