GB2180559A

GB2180559A - Circular knitting machine with improved patterning device

Info

Publication number: GB2180559A
Application number: GB08611228A
Authority: GB
Inventors: Dieter Rothe; Bernd Biedermann; Siegfried Bottger; Manfred Kuhn; Jurgen Hunger
Original assignee: Kombinat Textima VEB
Current assignee: Kombinat Textima VEB
Priority date: 1985-06-26
Filing date: 1986-05-08
Publication date: 1987-04-01
Also published as: DE3612969A1; ES556724A0; GB2180559B; ES8704559A1; GB8611228D0; DD238632A1

Abstract

A pattern device for circular knitting machines, in particular R/L circular rib knitting machines comprising sinkers (4) which are mounted between the needles and can be moved in the opposite direction to the needles, enables a reliable selection of the needles in a three-way technique, without this entailing an expensive cam construction, by providing each needle (1) with two feet (16; 17) arranged one above the other, and two pattern wheels (20; 21), also arranged one above the other, are provided for each knitting system as pattern carriers to influence a respective group of needle feet (16 or 17) arranged at the same level, one (20) of the said wheels being rotatable in a plane which rises in the direction of rotation of the needle cylinder and the other (21) being rotatable in a plane which slopes downwards in relation to the direction of rotation of the needle cylinder. The wheel (20) carries two types of bit respectively for tucking and knitting selection while the wheel (21) performs a selection for backing (sic). <IMAGE>

Description

SPECIFICATION Circular knitting machine with improved patterning device The present invention relates to a circular knitting machine with an improved patterning device and has particular but not exclusive application to R/L circular rib knitting machines.

A conventional R/L circular knitting machine has needles which can be moved in their longitudinal direction in grooves of a rotary needle cylinder. Sinkers project between the needles and can be moved transverse to and longitudinally of the needles by a sinker cam formed from like segments each belonging to a respective knitting system, so as to enable the distance required for forming a stitch to be covered partly by the needles guiding the yarn and partly by the sinkers. At least one programmable, external pattern carrier is provided per knitting system, which can be driven by the needle cylinder and which has a cylindrical surface formed with grooves to accommodate sinkers which influence the needles.

One form of pattern carrier comprises a pattern drum whose surface comprises grooves for accommodating various types of needle drivers which are expelled according to the pattern, by a cam associated with the drum.

In this case the drum is driven by the needle cylinder via a spur-gear stage (WP DO 4B/275 281 8).

It is quite expensive to manufacture and assemble this drum. It is necessary, particularly in the case of high needle counts, to reduce the spacing between the drum and the needle cylinder by a factor of two and to install two drums one above the other, the needle drivers of which are arranged in a staggered manner.

This increases the structural expense, particularly as regards the required cams.

An object of the invention is therefore to reduce the manufacturing costs of the circular knitting machine.

Another object of the invention is to provide a pattern device of the above-mentioned type in which the needles can be moved into the three positions for knitting, tucking and backing in a simple and reliable manner, without this entailing an expensive cam structure.

According to the invention there is provided a circular knitting machine comprising a rotary needle cylinder with a plurality of needles slidably mounted thereon to perform knitting strokes, and a patterning device for controlling said needle strokes, the patterning device including a wheel with a plurality of cam means which upon wheel rotation cause selective movement of the needles, the wheel having an axis of rotation arranged in a non-parallel configuration with the rotational axis of the cylinder.

In a preferred embodiment of the invention, each needle, or the component which raises the needle, is provided with two feet arranged one above the other, and that two pattern wheels, also arranged one able the other, are provided for each knitting system as pattern carriers to influence a respective group of needle feet arranged at the same level and can be driven by the needle cylinder directly via their sinkers, one of the said wheels being rotatable in a plane which rises in relation to the direction of rotation of the needle cylinder and the other being rotatable in a plane which slopes downwards in relation to the direction of rotation of the needle cylinder.

Preferably the angle of inclination of the pattern wheels with respect to the horizontal is approximately 35 to 50".

Preferably the pattern wheel which rotates in the plane which rises in relation to the direction of rotation of the needle cylinder is provided with two different types of sinkers which influence the needles.

The invention will now be described in detail with reference to an embodiment shown in the accompanying drawings, wherein: Figure 1 is a partial cross-section through the needle cylinder of a circular knitting machine fitted with a pattern device, in accordance with the invention, and Figure 2 is a partial development of the needleand sinker cam of the circular knitting machine fitted with the pattern device.

The latch needles 1 of the circular knitting machine fitted with the pattern device are mounted in grooves 2 of a needle cylinder 3 so as to be displaceable in the longitudinal direction. A sinker 4 is arranged between each two latch needles 1, engages over the needle cylinder edge 5 and is provided with a loop-forming edge 8 and a foot 7, which engages in the sinker cam 8. Each sinker 4 is mounted on a lever 9, which can be pivoted about its pivot 12 by two radially acting cams 10, 11. The sinker cam 8, which is formed from like segments 13, each associated with a knitting system, is mounted on a fixed bearing ring 14 of the machine, each segment 13 being secured to a support 15. Each latch needle 1 is provided with a clearing- and loop forming foot 16 and a drawing-off foot 17, which co-operate with the stationary cam systems 18 or 19.The upper cam system 18 comprises, in the conventional manner, a vertically adjustable loop-forming slide 18a, while the lower one comprises a stationary guard cam 19a.

Each knitting system of the circular knitting machine is provided with two pattern wheels 20; 21 which can be driven directly by the needle cylinder 3. the axis of the wheels 20; 21 is in each case inclined at a different angle with respect to the vertical, i.e. the lower pattern wheel 20 rotates in a plane which rises in relation to the direction of rotation of the needle cylinder (see arrow A in Figure 2), while the other wheel (21) rotates in a plane which slopes downwards in relation to the direction of rotation of the needle cylinder 3.

The surface lines, which are included at the same angle with respect to the axes, of each wheel 20; 21 are provided in the conventional manner with grooves into which sinkers 22 are inserted in accordance with the pattern. In the selected embodiment three different types of sinkers 22a; 22b; 22c are inserted in the wheels 20; 21. Thus, stated differently the axes of rotation of each of the wheels 20, 21 are arranged in a non-parallel configuration to the rotation axis of the cylinder 3, and the axes of the wheels lie in a common plane parallel to the axis of the cylinder 3.

The needle pitch of the cylinder corresponds to the pitch of the pattern wheels 20; 21, the sinkers 22 of which engage between the flanges 23 of the needle cylinder 3, so that these wheels 20; 21 rotate at the circumferential speed of the needle cylinder 3.

The pattern wheels 20; 21 are in each case mounted between two plates 24; 25 and 26; 27, which are held by a common support 28.

The method of operation of the circular knitting machine fitted with the pattern device according to the invention will be explained in detail in the following.

Before entering a knitting system (see arrow A in Figure 2), the needles 1 are adjusted to a uniform level by means of their feet 16 by the cam system 18 of the preceding knitting system. This ensures that, according to the programming of the pattern wheels 20; 21 with sinkers 22a; 22b; 22c, one of the two needle feet 16 or 17 is influenced by one of the two pattern wheels 20 or 21 when the needle cylinder 3 is rotated further.

The pattern wheels 20; 21 are programmed according to the pattern such that either a sinker 22a or 22b of the upper wheel 20 corresponds to the upper foot 16 of a needle 1 on the surface line, corresponding to this foot, of the wheels 20; 21, or alternatively, a sinker 22a of the lower wheel corresponds to the lower foot 1 7 of the relevant needle 1, i.e. either the foot 16 of a needle 1 is influenced solely by the sinkers 22a or 22b of the upper pattern wheel 20, or the foot 17 of a needle 1 is influenced solely by the sinker 22a of the lower pattern wheel.

If the foot 16 comes into contact with a sinker 22a of the pattern wheel 20, the relevant needle 1 is raised into the knitting position in accordance with the angle of inclination of the pattern wheel 20, which has taken over the function of the needle raising part. How ever if the foot 16 comes into contact with a sinker 22b, the relevant needle 1 carries out a yarn tucking movement. In neither of the above-mentioned cases can the foot 17 of the relevant needle 1 be influenced by the pattern wheel 21, as a sinker 33c is inserted in the relevant grooves of the pattern wheel 21 and only serves a stabilizing purpose.

However if the foot 17 comes into contact with a sinker 22a of the pattern wheel 21, the corresponding needle 1 is caused to carry out a backing movement, while a sinker 22c is then inserted in the corresponding groove of the pattern wheel 20, which sinker 22c cannot influence the relevant needle 1.

After the needles 1 have been raised by the pattern wheel 20 for tucking or knitting, they are lowered by the loop-forming part 18a.

The loop-forming procedure takes place outside of the area in which the needle cylinder 3 and the pattern wheels 20; 21 come into contact with one another. In order to prevent the feet 16 of the needles 1 provided for backing from colliding with the corner of the loopforming part 18a, its feet 17 are guided in an appropriate manner by the underside of the guard cam 19a.

At the end of the cam systems 18; 19 the needles 1 are again adjusted ny means of their feet 16 by the cam system 18 to a uniform level, so that a new selection of the needles 1 can subsequently be carried out by the pattern wheels of the next knitting system (the cam system on the left-hand side in Figure 2, which does not show the pattern wheels for reasons of clarity).

The movement of the sinkers 4 in the needle-raising direction and transverse to the latter remains the same in each system. In fact, after the loop has been cleared, the sinkers 4 at each latch clearing point are moved in a manner known per se against the drawing-off movement of the associated needles 1 (by the respective segment 13 of the sinker cam) and outwards transverse to the latter (by the cam 11, which acts on the lever 9) and, after the stitch has been cast off, against the needleraising direction (again by the segment 13) and inwards transverse to the latter (by the cam 10, which also acts on the lever 9) (see Figures 1 and 2).

The pattern device enables the needles 1 to carry out a knitting, tucking or backing movement, according to the pattern, without this entailing an expensive cam construction.

It is obvious that, without departing from the scope of the present invention, it would easily be possible to associate the two pattern wheels 20; 21 with needle drivers instead of the needles 1; these needle drivers would then be provided with two feet. It would also be possible to associate the pattern wheel 20 which raises the needles with the needle drivers and the pattern wheel 21 which withdraws the needles with the latter.

Claims

1. A circular knitting machine comprising a rotary needle cylinder with a plurality of needles slidably mounted thereon to perform knitting strokes, and a patterning device for controlling said needle strokes, the patterning device including a wheel with a plurality of cam means which upon wheel rotation cause selective movement of the needles, the wheel having an axis of rotation arranged in a nonparallel configuration with the rotational axis of the cylinder.

2. A circular knitting machine according to claim 1 wherein the patterning device includes a further said wheel, the axis of rotation of the wheels lying in a common plane, and said axis of rotation of the cylinder lying parallel to said common plane.

3. A circular knitting machine according to claim 2 wherein the rotational axis of the cylinder is generally vertically disposed, and said wheels rotate within respective planes which rise and fall respectively in the rotational direction of the cylinder.

4. Pattern device according to claim 2 or 3 characterised in that the angle of inclination of the pattern wheels is 35 to 50 with respect to the horizontal.

5. Pattern device according to claim 3, characterised in that the pattern wheel which rotates in the plane which rises in relation to the direction of rotation of the needle cylinder is provided with two different types of sinkers which influence the needles.

6. A circular knitting machine according to any preceding claim wherein the needles are formed with feet to be driven by the cam means of the patterning device.

7. A circular knitting machine according to any of claims 1 to 5 including needle drivers for moving the needles, said needle drivers being driven by said cam means.

8. A circular knitting machine according to any preceding claim including stationary cams adjacent said wheel(s) and arranged to move the needles to predetermined positions after movement by said cam means.

9. A circular knitting machine according to any preceding claim including sinkers, and sinker cams for moving the sinkers in such a manner that stitch formation is acheived by a combined movement of the needles and sinkers relative to the needle cylinder.

10. Pattern device for circular knitting machines, in particular R/L circular rib knitting machines, comprising needles which can be moved in their longitudinal direction in the grooves of the needle cylinder, sinkers which project between the needles and can be moved transverse to the needles and in the latters' longitudinal direction by a sinker cam formed from like segments each belonging to a respective knitting system, so as to enable the distance required for forming a stitch to be covered partly by the needles guiding the yarn and partly by the sinkers, and at least one programmable, external pattern carrier per system, which can be driven by the needle cylinder and whose cyiindr ical surf ace comprises grooves to accommodate sinkers which influence the needles, characterised in that each needle, or the component which raises the needle, is provided with two feet arranged one above the other, and that two pattern wheels also arranged one above the other, are provided for each knitting system as pattern carriers to influence a respective group of needle feet arranged at the same level and can be driven by the needle cylinder directly via their sinkers, one of the said wheels being rotatable in a plane which rises in relation to the direction of rotation of the needle cylinder and the other being rotatable in a plane which slopes downwards in relation to the direction of rotation of the needle cylinder.

11. A circular knitting machine substantially as herein described with reference to the accompanying drawings.

12. A pattern device for a circular knitting machine, substantially as herein described with reference to the accompanying drawings.