GB2120684A - Needle bed for knitting machines - Google Patents

Abstract

A needle bed 1 for a flat (as shown) or circular knitting machine has a projection 2 downstream of the needles, so that the newly formed fabric 4 passes over it. The projection 2 resists movement of the fabric back towards the needles. This is useful in the avoidance of defects when the working width of the needles is increased. The needle bed 1 can be used in conjunction with an oscillating bar 6 which alternately grips and releases the fabric 4 synchronously with the operation of the machine. <IMAGE>

Description

SPECIFICATION Needle bed for knitting machines The present invention relates to a needle bed for automatic knitting machines. It is concerned to assist the functioning of the tensionless knitting mechanism in automatic rectilinear knitting machines which forms the subject of Spanish Utility Model No. 264,599 applied for in the name of the present applicant The needle bed of the present invention may also be used to advantage without the mechanism referred to in the aforesaid Spanish Utility Model No. 264,599.

In the production of knitted fabric in automatic machines a problem arises when the working width of the needles changes abruptly from a smaller to a larger width. When this occurs, the needles starting to work pull up the fabric and defects are caused which affect the continuity of the process.

The solutions which were known before the production of the mechanism forming the subject of Spanish Utility Model No. 264,599 were rather complicated. That Utility Model proposed a simple mechanism based on an oscillating bar making reciprocating movements, synchronised with the operation of the machine. A free working edge of the bar is spaced from the needle bed in one position, releasing the fabric and freeing the stitches which are being formed, while in the other position it bears against the needle bed, gripping the newly knitted fabric and preventing it from being pulled up by the needles.

The needle bed forming the subject of the present application has a new restraining means for the fabric which may be used without the oscillating bar, although it is preferred to use it conjointly with the bar.

The present invention provides a needle bed with a projection so disposed that newly formed fabric moves down over it but is so directed as to resist movement of the fabric up back towards the needles. Usually this will mean that the projection is on the face of the bed away from the side where the thread forming the stitches enters and towards the knitted fabric leaving the bed.

An embodiment of the invention, given by way of example, will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of a needle bed embodying the invention with a bar in a position gripping the fabric formed; Figure 2 is a similar view of Figure 1, but showing the bar in the position in which it is spaced from the needle bed and does not grip the fabric; and Figure 3 is a detail on a larger scale, of the needle bed with the bar in the position of Figure 1.

The needle bed 1 is equipped at its top end with a tooth-shaped projection 2 which projects from the face opposite the side of the bed where the thread 3 enters, and which is directed approximately in the same direction as the movement of the fabric 4 formed.

Immediately following the projection 2 (in the direction of movement of the fabric), the needle bed has a depression 5 of such a shape that between the depressions of facing beds a space is formed in which a bar 6 can move, this bar being adapted to move rotationally in reciprocating angular movements and being mounted on a movable shaft 7 adapted to be synchronised with the operation of the machine, in such a manner that in one position the bevelled free end 6a of the bar 6 grips the fabric 4 and prevents it from rising (Figures 1 and 3) while in the opposite position it frees the fabric (Figure 2).

Even without the oscillating bar 6, the needle bed described may be able to pevent, or at least inhibit, the fabric 4 from rising, since the projection 2 offers an impediment to the backward movement of the fabric.

When used with the oscillating bar 6, this needle bed will be very effective to secure the fabric against rising. As shown in Figures 1 and 3, the end 6a of the bar 6 will grip the fabric 4 below the tooth 2.

In cases where the needle bed is used in conjunction with the bar, it should be pointed out that the space in which the bar 6 moves, formed by the inclined planes 5 situated below the projections 2, is increased.

The needle bed described can be applied to any type of knitting machine which has a needle bed, including circular machines.

1. A needle bed for a knitting machine, the bed having a projection so disposed that in use newly formed fabric passes over the projection as it moves away from the needles, the projection being so directed that it resists movement of the fabric back towards the needles.

2. A needle bed according to Claim 1 in which the projection is on a face of the bed away from the side of the bed where the thread enters.

3. A needle bed substantially as herein described with reference to and as illustrated in the accompanying drawing.

4. A knitting machine having a needle bed according to any one of Claims 1 to 3 in which there is also an oscillating bar which moves in use synchronously with the operation of the machine between a first position in which it presses the newly formed fabric against the bed next to the projection on its side remote frorn the needles, and a second position in which it releases the fabric.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Needle bed for knitting machines The present invention relates to a needle bed for automatic knitting machines. It is concerned to assist the functioning of the tensionless knitting mechanism in automatic rectilinear knitting machines which forms the subject of Spanish Utility Model No. 264,599 applied for in the name of the present applicant The needle bed of the present invention may also be used to advantage without the mechanism referred to in the aforesaid Spanish Utility Model No. 264,599. In the production of knitted fabric in automatic machines a problem arises when the working width of the needles changes abruptly from a smaller to a larger width. When this occurs, the needles starting to work pull up the fabric and defects are caused which affect the continuity of the process. The solutions which were known before the production of the mechanism forming the subject of Spanish Utility Model No. 264,599 were rather complicated. That Utility Model proposed a simple mechanism based on an oscillating bar making reciprocating movements, synchronised with the operation of the machine. A free working edge of the bar is spaced from the needle bed in one position, releasing the fabric and freeing the stitches which are being formed, while in the other position it bears against the needle bed, gripping the newly knitted fabric and preventing it from being pulled up by the needles. The needle bed forming the subject of the present application has a new restraining means for the fabric which may be used without the oscillating bar, although it is preferred to use it conjointly with the bar. The present invention provides a needle bed with a projection so disposed that newly formed fabric moves down over it but is so directed as to resist movement of the fabric up back towards the needles. Usually this will mean that the projection is on the face of the bed away from the side where the thread forming the stitches enters and towards the knitted fabric leaving the bed. An embodiment of the invention, given by way of example, will now be described with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of a needle bed embodying the invention with a bar in a position gripping the fabric formed; Figure 2 is a similar view of Figure 1, but showing the bar in the position in which it is spaced from the needle bed and does not grip the fabric; and Figure 3 is a detail on a larger scale, of the needle bed with the bar in the position of Figure 1. The needle bed 1 is equipped at its top end with a tooth-shaped projection 2 which projects from the face opposite the side of the bed where the thread 3 enters, and which is directed approximately in the same direction as the movement of the fabric 4 formed. Immediately following the projection 2 (in the direction of movement of the fabric), the needle bed has a depression 5 of such a shape that between the depressions of facing beds a space is formed in which a bar 6 can move, this bar being adapted to move rotationally in reciprocating angular movements and being mounted on a movable shaft 7 adapted to be synchronised with the operation of the machine, in such a manner that in one position the bevelled free end 6a of the bar 6 grips the fabric 4 and prevents it from rising (Figures 1 and 3) while in the opposite position it frees the fabric (Figure 2). Even without the oscillating bar 6, the needle bed described may be able to pevent, or at least inhibit, the fabric 4 from rising, since the projection 2 offers an impediment to the backward movement of the fabric. When used with the oscillating bar 6, this needle bed will be very effective to secure the fabric against rising. As shown in Figures 1 and 3, the end 6a of the bar 6 will grip the fabric 4 below the tooth 2. In cases where the needle bed is used in conjunction with the bar, it should be pointed out that the space in which the bar 6 moves, formed by the inclined planes 5 situated below the projections 2, is increased. The needle bed described can be applied to any type of knitting machine which has a needle bed, including circular machines. CLAIMS

1. A needle bed for a knitting machine, the bed having a projection so disposed that in use newly formed fabric passes over the projection as it moves away from the needles, the projection being so directed that it resists movement of the fabric back towards the needles.

2. A needle bed according to Claim 1 in which the projection is on a face of the bed away from the side of the bed where the thread enters.

3. A needle bed substantially as herein described with reference to and as illustrated in the accompanying drawing.

4. A knitting machine having a needle bed according to any one of Claims 1 to 3 in which there is also an oscillating bar which moves in use synchronously with the operation of the machine between a first position in which it presses the newly formed fabric against the bed next to the projection on its side remote frorn the needles, and a second position in which it releases the fabric.