GB1567608A

GB1567608A - Method and apparatus for the production of a warp knitted fabric

Info

Publication number: GB1567608A
Application number: GB3940376A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-09-15
Filing date: 1977-09-15
Publication date: 1980-05-21

Description

(54) A METHOD AND APPARATUS FOR THE PRODUCTION OF A WARP KNITTED FABRIC (71) We, ROBERT HARDY, a British Subject of 15 Hunt Avenue, Heanor, Derbyshire and BARRIE POWDRILL, a British subject of 40 Leamington Drive, Chilwell, Nottingham, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement: The present invention relates to a method and apparatus for the production of a warp knitted fabric.

According to one aspect of the present invention there is provided a method of producing a warp knitted fabric wherein during knitting one or more selected groups of adjacent needles are each fed with yarns for knitting pillars from a corresponding traversing group of adjacent yams, each group of adjacent yarns including one or more soluble yarns, each group of yarns being traversed during knitting by a desired number of needle spacings from a start position, the number of yarns in each group of yarns being greater than the number of adjacent needles in the corresponding group of adjacent needles so that during traversing each needle of the corresponding group is fed with a yarn from the group, and after knitting of the fabric dissolving said soluble yarns to remove them from the fabric.

According to another aspect of the present invention there is provided a warp knitting machine when used including at least two warp yarn feed bars for feeding yarn to the needles for knitting of a ground fabric, wherein a first of said yarn feed bars is arranged to feed yarn to selected groups of adjacent needles and a second of said yarn feed bars is arranged to feed groups of yarns to corresponding remainmg groups of adjacent needles, each group of yarns carried by the second feed bar containing at least one soluble yarn, traversing means operable on the second yarn feed bar to cause it to traverse yarns carried thereby by a desired number of needle spaces, the number of yarns contained in each group of yarns for feeding to a corresponding remaining group being greater in number than the number of adjacent needles in said corresponding group of adjacent needles so that during traversing all needles in said remaining groups of needles are fed with yarn.

Referring now to the drawings in which: Figure 1 is a schematic representation showing stitch structures according to the present invention; Figure 2 and 3 are schematic illustrations showing different effects attainable by varying the degree of traverse of a traversing group of yarns; Figure 4 is a more detailed representation of a construction of lace edging knitted in accordance with the present invention; and Figure 5 is a schematic side elevation showing in part a Raschel knitting machine adopted in accordance with the present invention.

In Figure 1, the vertical columns represent stitches or wales produced by each needle of the knitting machine and the horizontal rows represent the courses of the knitted fabric.

In figure 1, the vertical columns may be divided into three groups : - group A, group B and group C. The needles corresponding to groups A and C are fed with yarn from a main warp feed bar in a conventional manner. The needles corresponding to group B are fed with yarn from a different main warp feed bar which is cap able of traversing by a plurality of needle spacings (hereinafter referred to as the traversing feed bar).

The group of yarns fed by the traversing feed bar include at least one soluble yarn, in the example of figure 1 there are two adjacent soluble yarns as denoted by the crosses. The standard yarns feed to groups A and C of needles are denoted by dashes and the standard yarns fed by the traversing feed bar are denoted by circles.

Beginning at the top of Figure 1, as kniting commences the traversing feed bar is initially progressively traversed to the left by steps of one needle spacing to reach a maximum limit of traverse at course 3 and is then traversed to the right in order to reach a maximum limit of traverse at course 6. The traversing feed bar is then again traversed to the left.

It is essential that all the needles in group B are fed with yarn during traversing of the traversing feed bar and therefore the number of yarns supplied by the traversing feed bar is greater than the number of needles in group B.

Accordingly, the soluble yarns are caused to zig-zag in the walewise direction of the fabric. The combination of using soluble yarns and being able to traverse then enables different designs effects to be achieved and may also be used to effect separation of lace edges or galloons.

For example, if as illustrated in Figures 1 and 3, the soluble yarns are traversed so that they are always fed to group B needles then on dissolving of the soluble yarns separation of the fabric occurs as illustrated in Figure 3, providing of course other yarns have not been laid in across the soluble yarn warps. Accordingly, a scalloped edge 12is produced the depth of which may be varied by altering the traverse of the traversing feed bar.

As illustrated in Figure 2, if the traverse of the traversing feed bar is such that the soluble yarns are knitted on group A and group C needles, then after the soluble yarns have been dissolved, spaces 14 will appear in the fabric in those areas in which the group B needles have knitted with soluble yarn.

Additionally it will be appreciated that if desired, the soluble yarns may be used as a ground onto which non-soluble yarns are laid in so that after the soluble yarns have been dissolved free loops are left.

This is particularly applicable to the production of lace edging having a scalloped edge provided with free loops.

A specific example of such a lace edging is illustrated in Figure 4 in which the horizontal rows represent wales and the vertical lines represent 'courses'.

In Figure 4, groups A, B and C have again been identified the group A needles knitting pillars Al, As and A3 and the group C needles knitting pillars Ct, Cm and Ca.

The group B needles knit pillars Bi, B2 of the traversing soluble yarns Si, S2. The remaining yarns fed by the traversing feed bar have been omitted for sake of clarity.

A yarn 15 is fed to the needles by a pattern feed bar to lay in the yarn across the pillars Bi, Bi to form loops 16, the pattern feed bar being traversed in synchronism with the traversing feed bar so that after dissolving of the soluble yarn the loops 16 are unsupported and therefore hang freely. Accordingly, after dissolving of yarns Si, S2, the scalloped front edge of the lace edge is defined at wale 19. A needle adjacent the group C needles is also provided with soluble yarn S3 so as to knit a wale 20 which after yarn S3 has been dissolved defines a straight rear edge of a neighbouring lace edging. Thus after dissolving of the soluble yarns, fabric between wales 19 and 20 is waste.

It will be appreciated, that galloons may be produced by use of two traversing feed bars which are arranged to feed groups of traversing yarns to pairs of group B needles separated by groups of needles fed with yarn from a main guide bar, the two traversing feed bars being arranged to operate to provide galloons of desired shape.

In Figure 5 the drive mechanism for traversing the yarn feed bars of a Raschel warp knitting machine is schematically illustrated. The drive mechanism 30 has an upper drum 31 for driving the main feed bars and a lower drum 32 for driving the pattern feed bars. The traversing feed bar 34 is driven from the upper drum 31 by chain links 'E' the number of links 'E provided being sufficient to complete the knitting cycle. This necessarily means that the length of the chain composed of links 'E' in the illustrated Raschel machine is longer than used in normal knitting on a Raschel machine.

It will be appreciated, that if desired, the or each traversing feed bar may be driven from the lower drum by the adop tion of suitably shaped chain links 'S'.

It is to be noted that in this specification, soluble yarn is intended to mean a yarn having different solubility properties to the remaining yarns of the knitted fabric so that it may be removed from the fabric by immersing the fabric in a suitable solvent in which the soluble yarn is soluble but in which the remaining yarns are not soluble.

WHAT WE CLAIM IS: 1. A method of producing a warp knitted fabric-- wherein -during knitting one or more selected groups of adjacent needles are each fed with yarns for knitting pillars from a corresponding traversing group of adjacent yarns, each group of adjacent yarns including one or more soluble yarns, each group of yarns being traversed during knitting by a desired number of needle

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. in the example of figure 1 there are two adjacent soluble yarns as denoted by the crosses. The standard yarns feed to groups A and C of needles are denoted by dashes and the standard yarns fed by the traversing feed bar are denoted by circles. Beginning at the top of Figure 1, as kniting commences the traversing feed bar is initially progressively traversed to the left by steps of one needle spacing to reach a maximum limit of traverse at course 3 and is then traversed to the right in order to reach a maximum limit of traverse at course 6. The traversing feed bar is then again traversed to the left. It is essential that all the needles in group B are fed with yarn during traversing of the traversing feed bar and therefore the number of yarns supplied by the traversing feed bar is greater than the number of needles in group B. Accordingly, the soluble yarns are caused to zig-zag in the walewise direction of the fabric. The combination of using soluble yarns and being able to traverse then enables different designs effects to be achieved and may also be used to effect separation of lace edges or galloons. For example, if as illustrated in Figures 1 and 3, the soluble yarns are traversed so that they are always fed to group B needles then on dissolving of the soluble yarns separation of the fabric occurs as illustrated in Figure 3, providing of course other yarns have not been laid in across the soluble yarn warps. Accordingly, a scalloped edge 12is produced the depth of which may be varied by altering the traverse of the traversing feed bar. As illustrated in Figure 2, if the traverse of the traversing feed bar is such that the soluble yarns are knitted on group A and group C needles, then after the soluble yarns have been dissolved, spaces 14 will appear in the fabric in those areas in which the group B needles have knitted with soluble yarn. Additionally it will be appreciated that if desired, the soluble yarns may be used as a ground onto which non-soluble yarns are laid in so that after the soluble yarns have been dissolved free loops are left. This is particularly applicable to the production of lace edging having a scalloped edge provided with free loops. A specific example of such a lace edging is illustrated in Figure 4 in which the horizontal rows represent wales and the vertical lines represent 'courses'. In Figure 4, groups A, B and C have again been identified the group A needles knitting pillars Al, As and A3 and the group C needles knitting pillars Ct, Cm and Ca. The group B needles knit pillars Bi, B2 of the traversing soluble yarns Si, S2. The remaining yarns fed by the traversing feed bar have been omitted for sake of clarity. A yarn 15 is fed to the needles by a pattern feed bar to lay in the yarn across the pillars Bi, Bi to form loops 16, the pattern feed bar being traversed in synchronism with the traversing feed bar so that after dissolving of the soluble yarn the loops 16 are unsupported and therefore hang freely. Accordingly, after dissolving of yarns Si, S2, the scalloped front edge of the lace edge is defined at wale 19. A needle adjacent the group C needles is also provided with soluble yarn S3 so as to knit a wale 20 which after yarn S3 has been dissolved defines a straight rear edge of a neighbouring lace edging. Thus after dissolving of the soluble yarns, fabric between wales 19 and 20 is waste. It will be appreciated, that galloons may be produced by use of two traversing feed bars which are arranged to feed groups of traversing yarns to pairs of group B needles separated by groups of needles fed with yarn from a main guide bar, the two traversing feed bars being arranged to operate to provide galloons of desired shape. In Figure 5 the drive mechanism for traversing the yarn feed bars of a Raschel warp knitting machine is schematically illustrated. The drive mechanism 30 has an upper drum 31 for driving the main feed bars and a lower drum 32 for driving the pattern feed bars. The traversing feed bar 34 is driven from the upper drum 31 by chain links 'E' the number of links 'E provided being sufficient to complete the knitting cycle. This necessarily means that the length of the chain composed of links 'E' in the illustrated Raschel machine is longer than used in normal knitting on a Raschel machine. It will be appreciated, that if desired, the or each traversing feed bar may be driven from the lower drum by the adop tion of suitably shaped chain links 'S'. It is to be noted that in this specification, soluble yarn is intended to mean a yarn having different solubility properties to the remaining yarns of the knitted fabric so that it may be removed from the fabric by immersing the fabric in a suitable solvent in which the soluble yarn is soluble but in which the remaining yarns are not soluble. WHAT WE CLAIM IS:

1. A method of producing a warp knitted fabric-- wherein -during knitting one or more selected groups of adjacent needles are each fed with yarns for knitting pillars from a corresponding traversing group of adjacent yarns, each group of adjacent yarns including one or more soluble yarns, each group of yarns being traversed during knitting by a desired number of needle

spacings from a start position, the number of yarns in each group of yarns being greater than the number of adjacent needles in the corresponding group of adjacent needles so that during traversing each needle of the corresponding group is fed with a yarn from the group, and after knitting of the fabric dissolving said soluble yarns to remove them from the fabric.

2. A method according to claim 1 wherein traversing of the or each traversing group of yarns is effected so that at least one soluble yarn contained in a traversing group of yarns is traversed from the corresponding group of needles to be knitted on a needle adjacent to said corresponding group of needles.

3. A method according to claim 2 wherein traversing of the or each traversing group of yarns is effected so that all the soluble yarns contained in a traversing group of yarns are traversed from the corresponding group of needles to be knitted on needles adjacent to said corresponding group of needles.

4. A method according to claim 1 wherein traversing of the or each traversing group of yarns is effected so that at least one soluble yarn contained in a traversing group of yarns is knitted by the needles of said corresponding group of needles throughout knitting of the fabric.

5. A method according to any preceding claim wherein the or each traversing group of adjacent yarns are repeatedly traversed first in one direction and then in the opposite direction.

6. A method according to any preceding claim wherein during knitting, one or more yarns are laid in across one or more of the soluble yarns contained in a traversing group of yarns.

7. A method of producing a warp knitted fabric substantially as described hereinbefore with reference to the accom panying drawings.

8. A warp knitting machine when used including at least two warp yarn feed bars for feeding yarn to the needles for knitting of a ground fabric, wherein a first of said yarn feed bars is arranged to feed yarn to selected groups of adjacent needles and a second of said yarn feed bars is arranged to feed groups of yarns to corresponding remaining groups of adjacent needles, each group of yarns carried by the second feed bar containing at least one soluble yarn, traversing means operable on the second yarn feed bar to cause it to traverse yarns carried thereby by a desired number of needle spaces, the number of yarns contained in each group of yarns for feeding to a corresponding remaining group being greater in number than the number of adjacent needles in said corresponding group of adjacent needles so that during traversing all needles in said remaining groups of needles are fed with yarn.

9. A warp knitting machine according to claim 8 wherein the knitting machine is a Raschel type knitting machine having upper and lower drive drums for operating the main yarn feed bars and the pattern yarn feed bars respectively and wherein the upper drum is adapted to drive said traversing means.

10. A warp knitting machine according to claim 8 wherein the knitting machine is a Raschel type knitting machine having upper and lower drive drums for operating the main yarn feed bars and the pattern yarn feed bars respectively and wherein the lower drive drum is adapted to drive the traversing means.

11. A warp knitting machine substantially as herein described with reference to and as illustrated in Figure 5 of the accompanying drawings.