GB2038890A - Forming Loops in Knitting Machines - Google Patents

Abstract

A method of forming loops in latch-needle circular knitting machines consists in that the needle does not move in the active sense for the purpose of forming loops, but only in the sense of selecting the type of loop, i.e. a plain or a tuck-stitch pattern, or for forming a plated fabric. The main knitting motions of clearing and knocking-over are taken over by the sinker which is controlled on one hand radially displaceably and on the other hand swingably about 51, this making possible a substantial enhancement of the knitting speed. <IMAGE>

Description

SPECIFICATION Method of Forming Loops in Knitting Machines The present invention relates to a method of forming loops in knitting machines, particularly in small diameter circular knitting machines for manufacturing hosiery and similar goods by means of needles and sinkers.

Knitting machines are known, particularly small diameter circular knitting machines for manufacturing hosiery goods, in which loops are formed by means of needles and sinkers, said needles moving in vertical direction and said sinkers in horizontal direction, or possible an inclined or composed motion in both the horizontal and vertical direction. The loops are thus formed upon simultaneous movement of needles and sinkers.

The disadvantage of the above mentioned method of loop forming is the limitation of increasing the number of revolutions, which is given by both the inertial and centrifugal forces acting upon the needle, particularly upon the beard and the latch during rotation of the needle cylinder and the needle motion inside its grooves.

Furthermore, there is still another disadvantage consisting in that the impact of the needle butt against the cam causes the needle to oscillate, whereby the quality of the knit goods is affected.

The purpose of the present invention consists substantially in mitigating the above disadvantages in a simple manner.

According to one aspect of the invention there is provided a method of forming loops in knitting machines, particularly in small diameter circular knitting machines for manufacturing hosiery goods and similar by means of needles and sinkers, wherein by lifting the old loops from the shanks of needles over the latches by means of sinkers, new loops are cleared from yarn laid into the beards of stationary needles in a direction above the needle beards, said new loops being knocked over by sinkers behind needles, and drawn in a downward direction by sinkers from the beards of needles.

According to another aspect of the invention there is provided in a circular knitting machine for performing the above mentioned, comprising sinker cams for swinging out the upper operative end of each sinker and cams for displacement in horizontal direction, said sinkers being provided at their rear end with butts for horizontal displacement and at their front end with butts for the swinging motion.

According to a further aspect of the invention there is provided a sinker for the above method and the above circular knitting machine, wherein the front end of the sinker is provided with a circular butt for swinging out, made in the opposite direction to the operative end of the sinker, on which an operative tip for lifting loops is formed, as well as a recess for drawing loops over the headpart of needles.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 represents the position of both the needle and the sinker and their mounting in the sinker ring and the needle cylinder in a partial axial section through the needle cylinder and the sinker ring; Fig. 2 is a front view of the cams for lifting the front part of the sinkers; Figs. 3 to 8 show the method of loop forming by means of sinkers; Fig. 9 shows the course of the sinker tip during knitting in two views, i.e. from the front and from above, projected into a vertical plane, as well as the course of the needles; Fig. 10 shows the course of both the sinkers and needles in a 1:1 distribution for a float-plated pattern; Fig. 11 shows the same as in Fig. 10 with the needles distributed for knitting a tuck-stitch pattern; and Figs. 12, 13 and 14 are diagrams of knitting a plain structure, a tuck-stitch pattern, and a floatplated pattern.

A needle cylinder 1 is rotatably mounted in a not shown machine frame. In its longitudinal tricks 2, needles 3 are mounted. In the sinker ring 4, sinkers 5 are mounted for forming loops. In the front part of each sinker 5, a round sinker butt 51 is formed, which is acted upon in the horizontal direction by circular sinker cams 6 and 7, which are interconnected e.g. by means of screws (not shown), and circular sinker cam 7 is fixed, e.g.

also by screws, to sinker ring 4. As can be observed in Fig. 2, at the point of the feed on the circular knitting cam 6, a sinker rising cam 8 is fixed. In the rear part of sinker 5, sinker butt 52 is arranged, which is acted upon by circular sinker cam 6.

The knitting method by means of sinker 5 is specified above for forming loops is performed in the following manner: Upon knitting a plain structure, needles 3 pass, upon rotation of needle cylinder 1, at a constant height in accordance with path J (Fig. 9) denoting the course of their beard headparts. In front of the yarn laying point P (Fig. 12) by guide V into needles 3, the operative top 53 (Fig. 3) of sinkers 5 is in its lower position and the sinkers 5 are cleared from the centre of the needle cylinder 1 at a distance p by influence of surface 61 of the circular sinker cam 6.This position of sinker 5 is represented by point A' on curve P 1, which represents the course of the tip 53 of sinker 5 in a vertical direction, and point A on curve P2, which represents the course of tip 53 of sinker 5 in the horizontal plane according to Fig. 9, point S denoting the point of the start course of yarn P by needles 3.

Upon further rotation of needle cylinder 1 in the direction R, distance p does not change, as can be also observed from the course of curve P 1, as far as point B'. However, the operative tip 53 of sinker 5 is lifted by intermediary of the sinker rising cam 8 upon round sinker butt 51, as can be also seen from the course of curve P2 as far as the level of point B. The operative tip 53 of sinker 5 thus grips the old loop 61 at its sinker loop (Fig. 4), lifts it and draws it over the latch of needle 3, which is thus closed, as seen from Fig.

5. In the further course of rotation, a needle loop is begun to be formed at point S, due to lifting the old loop 01 above the headpoint of needle 3. The operative tip 53 is further lifted as far as level of point B, this corresponding to the clearing position, and the old loop 01 is cast-off.

During the further course of rotation, sinker 5 is drawn by the action of surface 71 of the circular sinker cam 7 upon butt 52 towards the centre of the needle cylinder and simultaneously, the operative tip 53 of said sinker 5 is lowered by action of the sinker stich cam 8. Upon this action, the needle loop 02 (Figs. 6 and 7) is pulled over the beard of needle 3 behind its shank. This situation between points B', C', on curve P1 or points B,C, on curve P2, respectively, is shown in Fig. 6, in which the beginning of pulling loop 02 is demonstrated, said loop 02 being gripped by recess 54 in the front part of sinker 5.In Fig. 7, this pulling by means of recess 54 is already better shown, and this position corresponds to point D on curve P2, the operative tip 53 being already maximally displaced towards the centre of needle cylinder 1, this corresponding to the level of point C' on curve P1. Upon further turning, or behind point C', respectively, sinker 5 is being acted upon only by sinker stitch cam 9, and the newly formed loop is drawn from the beard of needle 3 over the latch, as shown in Fig. 8, this corresponding to point B of curve P2 in the lower position, i.e. on the level of point A.

The whole course of loop forming by sinkers 5 and needles 3 is shown in Fig. 9.

By means of sinkers 5 and needles 3, it is also possible to knit a plated fabric. In comparison to knitting a plain structure, which was specified in the preceding description, there is a difference, consisting in distributing the needles in the required ratio, e.g. 1 :1, as will be explained further.

In front of the point S of laying yarn P e.g. the old needles 3 are guided by a cam - not shown into a pathc denoted by curve JL (Fig. 10), so that their beards move under the latches of the even needles 3, as can be seen in Fig. 13. Upon rotation in the direction R, the odd needles 3 are raised by a cam - not shown -- about curve JL simultaneously with sinkers 5 as far as the level of curve J. It is impossible with this method, as can be seen from Fig. 13, that yarn P is fed into or gripped by the beards of old needles 3, and no new loops are formed on them, while loops are formed only on even needles 3, as sinker 5 always lifts yarn P behind the point of the start course, or in front of said even needle 3, the odd needle 3 is not yet at the laying level, respectively.

It is possible to knit by means of sinkers 5 and needles 3 a tuck-stitch pattern. Needles 3 are again distributed as in the preceding case to odds and even in such a manner that the odd needles 3, or their beards, respectively, pass about curve JK (Fig. 1 1). The odd needles 3 are thus guided in such a manner that the old loops are situated on the open latches of odd needles 3, as can be seen from Fig. 14. Upon lifting odd needles 3 about curve JK, yarn P is thus laid into all needles 3, as shown in Fig, 14, as odd needles 3 with old loops on their latches were lifted on the level of curve J even before point S of laying yarn P into the needles.

The advantage of the specified method of knitting consists in that the main knitting motion is performed by sinkers, this making possible to increase the number of revolutions under the assumption of obtaining a high quality knitgood.

Claims (6)

Claims

1. A method of forming loops in knitting machines, particularly in small diameter circular knitting machines for manufacturing hosiery goods and similar by means of needles and sinkers, wherein by lifting the old loops from the shanks of needles over the latches by means of sinkers, new loops are cleared from yarn laid into the beards of stationary needles in a direction above the needle beards, said new loops being knocked over by sinkers behind needles, and drawn in a downward direction by sinkers from the beards of needles.

2. A circular knitting machine for performing the method as claimed in Claim 1, comprising sinker cams for swinging out the upper operative end of each sinker and cams for displacement in horizontal direction, said sinkers being provided at their rear end with butts for horizontal displacement and at their front end with butts for the swinging motion.

3. Sinker for the method as claimed in Claim 1 and a circular knitting machine as claimed in Claim 2, wherein the front end of the sinker is provided with a circular butt for swinging out, made in the opposite direction to the operative end of the sinker, on which an operative tip for lifting loops is formed, as well as a recess for drawing loops over the headpart of needles.

4. A method of forming loops in knitting machines, particularly in small diameter circular knitting machines for manufacturing hosiery goods and similar by means of needles and sinkers, substantially as hereinbefore described with reference to the accompanying drawings.

5. A circular knitting machine substantially as hereinbefore described with reference to the accompanying drawings.

6. A sinker substantially as hereinbefore described with reference to the accompanying drawings.