GB2058849A

GB2058849A - Circular knitting machine

Info

Publication number: GB2058849A
Application number: GB8030577A
Authority: GB
Original assignee: Camber International England Ltd
Current assignee: Camber International England Ltd
Priority date: 1979-09-22
Filing date: 1980-09-22
Publication date: 1981-04-15

Abstract

The invention provides a wrap yarn device in a circular knitting machine, the device comprising a two-limbed lever rotatable, together with a yarn eyelet (24) or aperture, about its own axis while revolving in the machine with the needle cylinder, so as to wrap a yarn (26) about selected needles (12) which are raised in a knitting attitude. The lever is first rotated about its axis in one direction by contact of one limb (22) with a first stationary projection and then in an opposite direction by contact of the second limb (28) with a second stationary projection (30). Thus rotary movement of the lever in both directions is positively controlled. <IMAGE>

Description

SPECIFICATION Circular knitting machine The present invention relates to a circular knitting machine and in particular such a machine when fitted with a wrap yarn feeder.

It is known to provide a circular jersey latch needle knitting machine with a wrap yarn feeder (sometimes known as a "wrapper") to produce a fabric embodying pattern and stripe designs extending along its wales. While the knitting needles move vertically under normal cam or other selection means, the wrapper passes yarn along the front of a needle or group of needlesto enable the yarn to be received into the needle hook or hooks. In this way one or more, for example, differently coloured yarns may be fed to the needles.

In accordance with the present invention there is provided a circular knitting machine having a wrap yarn feeder which comprises a rotatably mounted two-limbed lever, a yarn guide in the form of an eyelet or aperture for the passage of yarn therethrough and arranged for movement with said lever, the lever being mounted above the machine needle cylinder for synchronous movement therewith in such a manner that, when a needle or group of needles is raised in a knitting attitude and the lever is rotated between an inoperative and an operative position, yarn is wrapped across the front of the raised needle or group of needles, the mechanism for rotating the lever comprising a first projection disposed in the path of travel of a first limit of the lever to rotate the yarn guide from an inoperative position in which yarn passes to the rear of the needles to an operative position in which yarn is caused to pass in front of the needles, and a second projection disposed in the path of travel of the second limb of the lever to return the lever to the inoperative position.

Conveniently, the first projection is disposed radially outwardly of the yarn feeder in relation to the bed of the knitting machine and the second projection is disposed radially inwardly thereof.

The first projection may, for example, be in the form of a finger and the second projection in the form of an arcuate plate.

Advantageously, the first and second projections are each formed on one of two arms mounted on a stationary portion of the machine bed outwardly of the needles, that is, in front of the needles. The arm mounting the second projection extends radially inwards and above the needles so that the second projection extends downwardly therefrom in order to contact the second limb of any lever which has been moved into an operative position by contact with the first projection.

The eyelet or aperture for the passage of yarn may be positioned on or in the first limb of the lever, or, in another example, may be provided on a separate arm which is mounted for rotation with and adjacent to said first limb.

There will now be described two examples of wrap yarn devices for machines according to the invention. It will be understood that the description, which is to be read with reference to the drawings, is given by way of example only and not by way of limitation.

In the drawings: Figure 1 is a fragmentary perspective view showing part of the cylinder bed of a knitting machine according to a first example of the invention with three wrap yarn feeders disposed above the bed, a first projection operating on one feeder; Figure 2 is an enlarged view of one of the wrap yarn feeders of Figure 1 in an operative position and about to be contacted by a second projection to return the feeder to its inoperative position; Figure 3 is a plan view of part of four wrap yarn feeders brought intro and retained in the inoperative position; Figure 4 is a side view, partly in section of a second example of the invention; and Figure 5 is a diagrammatic plan view illustrating the movement of the lever of the second example.

In Figure 1 part of the bed of a circular jersey latch needle knitting machine is designated 1 0. A plurality of knitting needles 12 are received in needle slots between sinkers 14 for vertical sliding movement under known cam or selection means.

Wrap yarn feeders 16 are mounted upon a ring 18 which is itself mounted for synchronous movement with the rotating needle cylinder (not shown).

Each yarn feeder 1 6 consists of a lever 20 the outer end of one limb 22 of which carries a yarn guide in the form of an eyelet or pot-eye 24 for guiding yarn 26 therethrough towards the knitting needles 12. The other limb 28 (Figure 2) serves for engagement with a projection 30 in a manner to be described below. The lever is rotatably mounted upon a spindle and retained in position by a locknut 32. A bracket 34 serves to attach the yarn feeder to the ring 1 8.

Of the three wrap yarn feeders illustrated in Figure 1 the lever of the right hand unit is shown in an inoperative position, that is, the yarn coming through the feeder is passing to the rear of the knitting needles 12. In the illustrated embodiment, though not essentially, the lever is biased towards the inoperative position by means of a spring 36.

At times preselected in accordance with a knitting programme (not shown and not forming part of the invention), selected needles are raised in the needle cylinder to a level shown at 38. As the ring 1 8 rotates (in the direction of the arrow A Figure 1) the limb 22 of a feeder engages against a first fixed projection 40. Hence as the ring continues to rotate in the direction of arrow A, the lever 20 is rotated anti-clockwise, as viewed, in the direction of arrow E. Hence, the yarn 26 is fed to the front of the raised needles, so that as and when the needles are lowered - in accordance with the knitting programme -- the yarn is received into the hooks of the needles for knitting.

It will be seen that since successive limbs 22 lie in overlapped relationship, as one limb 20 is caused to rotate by projection 40, initiation of rotation of the next downstream limb 20 is also caused.

The second projection 30 (Figure 2) is fixedly mounted on the radially inner side of the feeder and is engageable against the limb 28 of any feeder which lies in an operative position. The relevant limb 28 is thus caused to rotate clockwise, as viewed, in the direction of arrow C to return the yarn into a path to the rear of the needles 12.

Figure 3 shows a group of levers each retained in an inoperative position by the presence of the second projection 30.

Whereas, in the first example of the invention, a spring 36 has been used to assist in maintaining the lever 20 in an inoperative position, it will be understood that a damper may be used to damp movement of the lever, the spring or damper not having any biasing effect towards the inoperative position. A suitable damper may be provided, for example, by a Belville washer arrangement.

The second example is described with reference to Figures 4 and 5 where these show details differing from the corresponding parts of the first example. In this example the ring 1 8 supports a bracket 42 at the free end of which is mounted a two-limbed lever indicated at 44.

The firstJimb 46 of this lever corresponds to the first limb 22 of Figures 1-3, but in the present example the part corresponding to the post-eye 24 is an aperture 48 in an arm 50 extending downwardly and outwardly of a boss 52 mounting the lever 44 upon the bracket 42. The yarn 26 is guided towards the aperture 48 through a pot-eye 54 which merely acts to ensure that the yarn path clears the operative path of the pivotting lever 44.

Two projections, 56 and 58, are provided which operate to pivot the lever 44 in a manner similar to the action of projections 40 and 30 respectively on the lever 20 of Figure l--3.Thus, both projections, 56, 58, are mounted upon a stationary portion of the machine bed, but in the present example, the projections 56, 58 are mounted on arms 60, 62, provided in front of, that is radially outwards of, the needles 12. Arm 62 extends inwardly and above the needles 12 to mount the projection 58 in a position to the rear of the needles 12 so that contact with the second limb 47 of the lever 44 will restore it to its inoperative position.

Figure 5 shows the movement of the lever 44 from an inoperative position 44' in which the projection 56 is contacted by the limb 46.

Continued rotation of the ring 18 in the direction of arrow D causes the lever to commence to pivot about its axis 53, as shown in successive dotted line positions, until the projection 56 is passed with the lever in the position 44". At this moment, since the distance between the two projections is the same as the overall length of the lever 44, the limit 47 contacts the projection 58, which contact causes the lever to pivot clockwise as it passes below the arm 62 and returns to the inoperative position, as shown at 44"'. The arm SQ which is fixed in a position immediately below and adjacent to the limb 46 therefore partakes of a yarn wrapping movement so that the yarn 26 is passed in front of the needles 12 as shown in Figure 4.

Suitable damping means may also be provided, if required, to damp the pivotting of the lever 44.

Claims

1. A circular knitting machine having a wrap yarn feeder which comprises a rotatably mounted two-limbed lever, a yarn guide in the form of an eyelet or aperture for the passage of yarn therethrough and arranged for movement with said lever, the lever being mounted above the machine needle cylinder for synchronous movement therewith in such a manner that, when a needle or group of needles is raised in a knitting attitude and the lever is rotated between an inoperative and an operative position, yarn is wrapped across the front of the raised needle or group of needles, the mechanism for rotating the lever comprising a first projection disposed in the path of travel of a first limb of the lever to rotate the yarn guide from an inoperative position in which yarn passes to the rear of the needles to an operative position in which yarn is caused to pass in front of the needles, and a second projection disposed in the path of travel of the second limb of the lever to return the lever to the inoperative position.

2. A machine as claimed in claim 1 , wherein the eyelet or aperture is provided in one limb of the two-limbed lever.

3. A machine as claimed in claim 2, wherein the eyelet or aperture is provided in the first limb of the lever.

4. A machine as claimed in claim 1, wherein the eyelet or aperture is mounted in a separate arm arranged for rotary movement with the twolimbed lever.

5. A machine as claimed in claim 4, wherein the arm is mounted on a boss upon which the lever is mounted and extends downwardly and outwardly of the boss.

6. A machine as claimed in any one of the preceding claims wherein the first projection is disposed radially outwardly of the yarn feeder with respect to the machine bed and the second projection is disposed radially inward thereof.

7. A machine as claimed in claim 6 wherein the first and second projections are mounted on a stationary portion of the machine bed, the second projection being mounted on an arm extending radially inwards and above the needles to permit the second projection to extend downwardly from the arm in order to contact the second limb of a lever which has been rotated into an operative position.

8. A machine as claimed in any of the preceding claims, wherein the rotating movement of the lever about its axis is damped by suitable damping means.

9. A circular knitting machine having a wrap yarn feeder, constructed, arranged and adapted to operate substantially as hereinbefore described with reference to and as shown in Figures 1 to 3 of the drawings.

10. A circular knitting machine having a wrap yarn feeder, constructed, arranged and adapted to operate substantially as herein before described with reference to and as shown in Figures 4 and 5 of the drawings.