FR2460354A1 - Forming lace or scalloped edge knitted fabric - using reciprocating yarn group including soluble yarn - Google Patents

Abstract

A traversing group(s) of yarns including soluble yarns is reciprocated during warp knitting relative to a selected group(s) of adjacent needles. There are more yarns in the traversing group than the number of adjacent needles in the selected needle group so that all needles in the selected needle group are fed with yarn during traversing. Ater knitting, the soluble yarn is dissolved away. A variable depth scalloped or lace-like edge, or sinuous or angled openings in the fabric, are formed after dissolving the soluble yarns.

Description

 The present invention relates to a method and a device for knitting a warp knitted fabric.

 According to one of the characteristics of the present invention, there is provided a method of knitting a warp knitted fabric or during knitting one or more selected groups of adjacent needles are each supplied with yarns for knitting columns from '' a corresponding group of adjacent threads moving back and forth, each group of adjacent threads comprising one or more soluble threads, each group of threads being crossed during knitting by a desired number of needle spacings from a starting position, the number of threads in each group of threads being greater than the number of adjacent needles in the corresponding group of adjacent needles so that during the crossing, each needle of the corresponding group is supplied with a thread, and after knitting the fabric there is dissolution of the soluble threads so as to remove them from the fabric.

 According to another aspect of the present invention, a warp knitting machine is provided which comprises at least two yarn feed bars for introducing the yarn into the needles and allowing knitting of a background fabric, ot the first of the yarn feed bars are arranged to introduce the yarn into selected groups of adjacent needles and the second of these bars is arranged to introduce yarn groups into the corresponding remaining groups of adjacent needles, each group of wires carried by the second bar containing at least one soluble wire, a reciprocating movement means that can operate on the second bar to bring it through the wires carried by the latter by a desired number of needle spacings, the number of threads contained in each group of threads for feeding a corresponding remaining group being greater than the number of adjacent needles of said corresponding group of adjacent needles entes, so that during the back and forth movement all the needles of said remaining groups of needles are fed with thread.

The present invention will be clearly understood on reading the following description given in relation to the attached drawings, in which
Figure 1 is a schematic representation which shows the stitch structures according to the present invention
Figures 2 and 3 are schematic representations which show the different effects obtained by varying the degree of crossing of a group of wires moving back and forth
Figure 4 is a more detailed representation of an embroidered knitted construction in embroidery according to the present invention; and
Figure 5 is a schematic side elevation partially showing a Raschel knitting machine adapted in accordance with the present invention.

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

 In Figure 1, the vertical columns can be divided into three groups: group A, group B and group C. The needles corresponding to groups A and C are supplied with thread from a main chain feed bar in the classic way. The needles corresponding to group B are supplied with thread from a different main chain feed bar which can be crossed by a plurality of needle spacings (hereinafter called back and forth feed bar - comes).

The group of wires supplied by the reciprocating feed bar comprises at least one soluble wire; in the example in figure 1, there are two adjacent soluble wires which are indicated by crosses. The standard wires introduced into groups A and C of needles are represented by dashes and the standard wires introduced by the reciprocating feed bar are represented by circles.

 From the top of Figure 1, when knitting begins, the reciprocating feed bar gradually moves to the left in stages of needle spacing so as to reach a limit maximum crossing at row 3, then moves to the right so as to reach a maximum crossing limit at row 6.

The reciprocating feed bar then moves to the left again.

It is essential that all the needles in the group
B are supplied with thread during the crossing of the reciprocating feed bar, and, consequently, the number of threads fed by this bar is greater than the number of needles in group B.

 Consequently, the soluble threads are caused to zig-zag in the direction of the ribs of the tissue. The combination of the use of soluble threads and the possibility of crossing then makes it possible to obtain different effects of patterns and can also be used to effect the separation of the edges in embroidery or braids.

 For example, if, as shown in FIGS. 1 and 3, the soluble threads are moved so that they always feed the needles of group B, the dissolution of the soluble threads will cause a separation of the tissue represented in FIG. 3, insofar as ol obviously other threads were not placed in the chains of soluble threads. As a result, a serrated edge 12 is produced, the depth of which can be varied by varying the traverse of the reciprocating feed bar.

 As shown in Figure 2, if the movement of the reciprocating feed bar is such that the soluble yarns are knitted on needles of group A and group C, after dissolution of the soluble yarns , spaces 14 will then appear in the fabric in the areas where the needles of group B have knitted the soluble yarn.

In addition, it will be noted that, if desired, the soluble wires can be used as a background on which non-soluble wires are placed so that after dissolution of the soluble wires, there remain free loops. This is particularly applicable to the prediction of a lace edge having a serrated edge with loops or a free part.

A specific example of such a lace edge is shown in Figure 4; the horizontal rows representing the ribs and the vertical lines representing the "rows of stitches
In Figure 4, groups A, B and C were again identified, the needles of group A knitting the columns A1, A2 and A3 and the needles of group C the columns C1, C2 and C3.

Group B needles knit columns B1,
B2 of the soluble wires Slr 52 The remaining wires introduced by the reciprocating feed bar have been omitted to make the figure clearer.

 A thread 15 feeds the needles by means of a pattern thread feed bar to place the thread through the columns B1, B2 and form loops 16, this bar moving in synchronism with the feed rod moving in va -and so that after dissolution of the soluble wire, the loops 16 are not supported and hang freely. Consequently, after dissolution of the threads Slr S2 the serrated front edge of the embroidery edge is defined at the coast 19. A needle adjacent to the needles of group C also comprises a soluble thread S3 so as to knit a rib 20 which, after dissolution of the S3 thread, defines a rectilinear rear edge of a neighboring border in embroidery. Thus, after dissolution of the soluble threads, the tissue between the ribs 19 and 20 is deserted.

It will be noted that stripes can be produced by the use of two reciprocating feed bars which are arranged so as to feed groups of wires which move the pairs back and forth. of needles of group B separated by groups of needles fed with thread from a main guide bar, the two feed bars reciprocating being arranged so as to give stripes having the desired shape.

In Figure 5, the drive mechanism for the back and forth movement of the yarn feed bars of a Raschel warp knitting machine is shown schematically. The drive mechanism 30 comprises an upper drum 31 for driving the main feed bars and a lower drum 32 for driving the feed bars in pattern thread. The reciprocating feed bar 34 is driven from the main drum 31 by so-called "E" links, the number of which is sufficient to complete the knitting cycle. This necessarily means that the length of the chain of links "E" in the Raschel machine illustrated is greater than that used in normal knitting on a Raschel machine.

It will be noted that, if desired, the reciprocating feed bar or each reciprocating feed bar can be driven from the lower drum by the adoption of links "S" of appropriate shape.

 Note that in this description "soluble yarn" means yarn having solubility properties different from those of the remaining yarns of the knitted fabric so as to be removed from the fabric by immersion thereof in an appropriate solvent where it is soluble but where the remaining wires are not.

The present invention is not limited to the embodiments which have just been described, it is on the contrary liable to variants and modifications which will appear to those skilled in the art.

Claims (9)

 1 - Method for knitting a warp knitted fabric, characterized in that during knitting one or more selected groups of adjacent needles are each supplied with threads for knitting columns from a corresponding through group of threads adjacent, each group of adjacent threads comprising one or more soluble threads, each group of threads being traversed back and forth during knitting by a desired number of needle spacings from a starting position , the number of threads in each group of threads being greater than the number of adjacent needles of the corresponding group of adjacent needles so that during the reciprocating movement each needle of the corresponding group is fed with a thread, and after knitting of the fabric the soluble yarns are dissolved so as to remove them from the fabric. 2 - Method according to claim 1, characterized in that the crossing of groups animated by a back-and-forth movement of wires or of each group of wires moving back-and-forth is carried out so that at least one soluble yarn contained in a group of yarns moving back and forth is crossed from the corresponding group of knitting needles on a needle adjacent to the corresponding group of needles. 3 - Method according to claim 2, characterized in that the crossing of groups animated by a back-and-forth movement of wires or each group animated by a back-and-forth movement is carried out so that all of the soluble wires contained in a group moving back and forth, threads are crossed from the corresponding group of knitting needles on needles adjacent to the corresponding groups of needles. 4 - Method according to claim 1, characterized in that the crossing of groups animated by a back-and-forth movement of wires or each group animated by a back-and-forth movement is carried out so that at least one wire soluble contained in a group animated by a back and forth movement of threads is knitted by the needles of the corresponding group of needles, during the entire knitting of the fabric.  5 - Method according to one of claims 1 to 4, characterized in that the crossing of groups animated by a back-and-forth movement or each group animated by a back-and-forth movement of son adjacent are crossed repeatedly in one direction and then in the opposite direction.  6 - Method according to one of claims 1 to 5, characterized in that during knitting, one or more threads are placed through one or more of the soluble threads contained in a group of threads animated back and forth - comes.  7 - Warp knitting machine comprising at least two yarn supply bars for feeding yarn the needles for knitting a background fabric, characterized in that one of the yarn feed bars is arranged so as to supply yarns with selected groups of adjacent needles and in that the second yarn supply bar is arranged so as to supply in yarn groups the corresponding remaining groups of adjacent needles, each group of yarns carried by the second feed bar containing at least one soluble wire, a means moving back and forth operating on the second wire feed bar so as to cause it to animate a back and forth movement back and forth the threads carried by a desired number of needle spacings, the number of threads contained in each group of threads for feeding a corresponding remaining group being greater than the number of adjacent needles of the corresponding group of adjacent needle es so that during the movement back and forth all the needles of the remaining groups of needles are supplied with thread. 8 - knitting machine according to claim 7, characterized in that it is a machine of the Raschel type, comprising upper and lower drive drums for actuating the main yarn feed bars and the yarn feed bars pattern, respectively, and in that the upper drum is provided to drive the through means.  9 - knitting machine according to claim 7, characterized in that it is a machine of the Raschel type comprising upper and lower drive drums for actuating the main yarn feed bars and the yarn feed bars. pattern, respectively and in that the lower drive drum is provided to drive the means moving back and forth.