GB2040321A

GB2040321A - Weaving apparatus

Info

Publication number: GB2040321A
Application number: GB8001594A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-01-20
Filing date: 1980-01-17
Publication date: 1980-08-28
Also published as: GB2040321B; FR2446879B3; IT8019292A0; AT365666B; FR2446879A1; IT1129558B; ATA774379A; CH641847A5

Abstract

An apparatus for producing a textile fabric selvedge provided with a leno or cross-weave especially in shuttleless looms, comprises two alternatively moved heald shafts (1,2). A needle holder (5) is arranged on the one heald shaft (1) and a main rail (10) with oblique slot on the other heald shaft (2). An auxiliary rail (15) of limited stroke is arranged to the main rail (10) to be moved relative thereto by magnets 19, 20 on head shaft (1). The auxiliary rail (15) has an oblique slot which is arranged crosswise with respect to the oblique slot of the main rail (10). Leno threads pass through the slots and thus can be crossed about the threads passing through the needles (6,7) to produce the required selvedge. <IMAGE>

Description

SPECIFICATION Weaving apparatus The present invention relates to an apparatus for producing a fabric edge provided with a crossweave, especially in shuttleless looms.

In shuttleless looms, the weft thread is introduced into the shed without the aid of a loom shuttle and cut off at the ends after insertion. Thereby, a textile fabric edge inclined to fraying is produced at the edge of the textile fabric.

Such unbound textile fabric edges are also produced when textile fabrics of very great width are produced. The fabrics comprise several fabric pieces, the edge warp threads of which have a greater spacing and are thereby separated from one another by a greater gap. Therefore, the weft thread can be severed in the greater gap after the production of the textile fabric. Also an unbound textile fabric edge is produced, which inclines to fraying.

An apparatus for the formation of a textile fabric edge provided with a cross-weave is known and comprises two heald shafts which are alternately moved vertically. A needle holder is arranged on one of the heald shafts and a main rail with oblique slot means is arranged on the other heald shaft. Two needles and two oblique slots are usually provided for the formation of a so-called turner binding, in order that the stationary threads can be conducted through the eyelets of the needles and the turner threads through the slots. For the formation of the binding, the needle holder makes a vertical motion.

The main rail with the oblique slot makes a vertical motion, wherein however the turner thread guided in the oblique slot executes a substantially horizontal reciprocatory motion, in that it assumes an end position in the slot each time on the upward and downward motion ofthe main rail,wherebythe substantially horizontal reciprocatory motion comes into being. This horizontal reciproccatory motion of the turner thread or threads in co-operating with the vertical motion of the stationary threads guided through the needle holder results in a turner crossweave.

The known apparatuses have the disadvantage that they can not be operated at high speeds, because it cannot then be ensured that the turner thread guided in the oblique slot will also assume at the desired instant of time the end position required.

These apparatuses therefore operate with a relatively large stroke of the main rail in order that the turner thread, due to the thereby greater thread tension, is able to assume the required end position in the oblique slot. However, also this measure is not successful at very high operating speeds.

According to the present invention there is provided an apparatus for producing a fabric edge provided with a cross-weave, comprising a first and a second displaceable heald shaft, a needle holder connected to the first heald shaft, a main rail provided with oblique slot means and connected to the second heald shaft, an auxiliary rail connected to the main rail and having a limited displacement relative to the main rail and provided with oblique slot means disposed crosswise with respect to the slot means of the main rail, the displacement of the auxiliary rail being dependent on displacement of the needle holder.

The needle holder may be provided with magnet means facing the auxiliary rail.

The auxiliary rail may comprise spring tongue means facing the magnet means.

The main rail and the auxiliary rail may be connected with each other by pins extending.

through elongate openings in the auxiliary rail to allowthe relative displacement between the main rail and the auxiliary rail.

The auxiliary rail may have a stroke, the length of which is adapted to the length of the slot means.

Each oblique slot means may comprise two slots inclined to each other.

The apparatus may comprise magnet means to influence guidance of the auxiliary rail during its displacement.

The needle holder may comprise mutually parallel frame rails disposed to guide the main and auxiliary rails therebetween.

The frame rails may each have a channel-shaped cross-section as a guide groove for the auxiliary rail and the main rail.

The main rail may be provided with abutments to limit displacement of the auxiliary rail.

The magnet means may be mounted to the auxiliary rail to the frame rails.

The apparatus may comprise strip means connecting the main rail with the heald shafts.

The strip means may comprise a metal or a plastics material.

By connecting the main rail with the auxiliary rail by pins extending through elongate openings in the auxiliary rail the stroke length of the auxiliary rail is matched to the slot length. This means that when the stroke is executed, the slot means on the one hand of the main rail and on the other hand of the auxiliary rail provide an exactly defined opening in the shape of a hole guide which corresponds to the end positions of the slot means.

By providing magnet means to influence guidance of the auxiliary rail during its displacement it is secured that the magnet force acts to the full extent on the auxiliary rail and can thereby entrain this regularly.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings in which Figure 1 shows in section an apparatus embodying the present invention, Figures 2 and 3 show different positions of the auxiliary rail with respect to the main rail in the embodiment shown in Figure 1, Figure 4 shows the needle holder, the auxiliary rail and the main rail in perspective view as arranged in Figure 1, but shown for clarity at a spacing from one another, Figure 5 shows in section another embodiment of the apparatus, Figure 6 shows a view on to the needle holder together with the main rail and the auxiliary rail from the front, the needle being omitted for clarity, Figure 7 shows a similar view to that shown in Figure 6, but with the auxiliary rail in another position with respect to the main rail, Figure 8shows a section along line Vlil-Vll of Figure 6 and Figure 9 shows a perspective partial view of the main rail together with the auxiliary rail in a frame rail.

Referring to Figure 1, an apparatus for forming a textile fabric edge comprises two alternatively moved heald shafts 1 and 2, which are for example connected with one another through a rope guide conducted over a roller 4 so that the heald shaft 2 moves downwardly when the heald shaft 1 moves upwardly. Fastened to the heald shaft 1 is a needle holder 5 carrying needles 6 and 7 which at the forward end are each provided with an eyelet 8 and 9, respectively, through which the so-called stationary threads are drawn. The needles 6 and 7 reach into a passage opening 5a of the needle holder 5.

The ends of the needles 6 and 7 lie opposite each other at a spacing (gap 24).

A main rail 10 is fastened to the heald shaft 2, for example with the aid of a clamping cheek 11 and 12, respectively. The main rail 10 is provided with two oblique slots 13 and 14, which are arranged angularly to each other and through which turner threads are drawn for forming a turner binding.

An auxiliary rail 15 is arranged in front of the main rail 10 and movably connected with the main rail. To provide this movement the auxiliary rail 15 is provided with an elongate hole 16, into which engages a pin 17, which is fastened to the main rail 10, so that the auxiliary rail 15 can execute a movement of limited stroke (corresponding to the length of the elongate hole) relative to the main rail.

The auxiliary rail 15 is provided with a spring tongue 18, which extends over the entire length of the auxiliary rail.

Magnets 19 and 20 are arranged on the needle holder 5 on the rearside, i.e. at the side facing the auxiliary rail 15 or the spring tongue 18.

Arranged in the auxiliary rail 15 are oblique slots 13a and 14a, which are disposed crosswise with respect to the oblique slots 13 and 14 of the main rail 10. An exactly defined opening, namely a guide 21 and 22 in the manner of a hole is provided by this crosswise arrangement of the oblique slots 13, 14 and 13a, 14a, respectively in the main rail 10 and in the auxiliary rail 15. The turner threads lie in this hole.

The manner of operation of the apparatus is as follows: Let it be assumed that the heald shaft 1 makes an upward movement according to arrow 23, the heald shaft 2 makes a downward movement. When the heald shaft 1 has arrived at the upper reversal position, then the heald shaft 1 makes a downward movement, whilst the heald shaft 2 makes an upward movement. During the reversing movement of the heald shaft, i.e. during the downward movement, the magnet 19 and 20, respectively, by means of the spring tongue 18 entrains the auxiliary rail 15 against the movement of the main rail 10 and effects a relative movement of auxiliary rail and main rail.

Thereby a redisposition of the turner thread results in the holelike guide 21 and 22, respectively, namely in the following manner: Let it be assumed that the turner thread was (as shown in Figure 3) in the holelike guide 22 on the left-hand side with respect to the needle 6 and on the right-hand side in the holelike guide 21, then a displacement of the turner threads in the oblique slots takes place due to the entrainment of the auxiliary rail 15 by the magnet 19; i.e. due to the holelike guide (formed by the oblique slots arranged crosswise), there results a constrained displacement of the turner threads from the one side of the needle 6 to the other side of the needle 6, during which the threads themselves at first remain on the one side of the needle 6 until they have reached the gap 24 between the needle points.The turner threads then continue to run on the opposite side of the needle 7 until the heald shafts 1 and 2, respectively, have reached the reversal position.

Shortly before the initiation of the reversing movement of the heald shafts, i.e. when the relative movement of the auxiliary rail 15 has terminated due to the magnets, the turner thread already has the tendency to get to the other side of the needle, i.e.

thus already pretensioned so that it is constrainedly guided to the other side of the needle at once in the instant, in which it has reached the gap 24 between the needles.

It is thereby secured that the thread even at high operating speeds always reaches the changing position in the oblique slots 13, 14 and 13a, 14a, respectively, required for the attainment of the turner binding.

In so far as no turner binding is desired, the crosswise arrangement of one oblique slot in the main rail or in the auxiliary rail suffices.

The embodiment, illustrated in the Figures 5 to 9 for the formation of a textile fabric edge provided with a cross-weave, comprises heald shafts 24 and 25. Each heald shaft comprises two heald carrier rails 26 or 26a and 27 or 27a, which are disposed at a spacing and which are for example connected with one another through the heald shaft frame 28. The guidance of each heald shaft takes place in a guide frame 28, which is illustrated only schematically.

The needle holder 50 is fastened to a heald shaft 25, i.e. at the heald carrier rail 26a or 27a, for example with the aid of clamping members 30 and 31. The needle holder 50 comprises two channel frame rails 29a and 29b which are arranged opposite each other and which each form a guide groove 32 (Figure 8). The needles of the needle holder are designated by 33 and 34, respectively. They are provided with eyelets 35 and 36, respectively through which the stationary threads are drawn.

The main rail 39 is connected with the heald carrier rail 26 of the heald shaft 24 with the aid of a band 40 and with the heald carrier rail 27 of the heald shaft 24 with the aid of a band 40a.

The auxiliary rail 41 is arranged in front of the main rail 39. This auxiliary rail 41 can execute a limited movement relative to the main rail. The limitation is assured by abutments 42 and 43, respectively, which are mounted to the main rail 39.

The auxiliary rail 41 is provided with magnets 43a and 44 at oppositely disposed sides (Figure 6).

The guidance of the main rail 39 and the auxiliary rail 41 takes place through the guide groove 32 formed by the frame rails 29a and 29b.

The main rail 39 as well as also the auxiliary rail 41 are provided with slots 45 and 46, respectively, which are arranged crosswise. Thereby, a defined holelike opening 47, through which the turner thread is drawn, is provided at the crossing point of the slots. In case several turner threads are to be used, correspondingly more slots must be provided.

The manner of operation of the apparatus is as follows; Let it be assumed that the heald shaft 24 with its heald carrier rails 26 and 27 has reached the upper position and then begins with the reversing movement in the direction of the arrow 48; the needle holder 50, which is fastened to the heald shaft 25, i.e.

at the heald carrier rails 26a and 27a, then makes a downward movement, i.e. in direction of the arrow 49.

The main rail 39, which is connected with the heald shaft 24, makes a downward movement. The auxiliary rail 41 however does not follow this downwardly directed movement, since it is magnetically connected with the needle holder, i.e. with the frame rails 29a and 29b. This auxiliary rail consequently makes an upward movement, and namely then relatively to the main rail, i.e. in direction of the arrow 49, until it hits against the abutment 42.

Through this relative movement of the auxiliary rail 41 with respect to the main rail 39, the position of the holelike opening 47 formed by the oblique slots 45 and 46 has correspondingly changed, i.e. from the position shown in Figure 7 into the position shown in Figure 6. The turner thread drawn through the holelike opening 47 has consequently executed a horizontal motion and consequently already bears against the needle with a certain tension. If during the further downward movement of the heald 24, this turner thread now gets into the region of the needle end, i.e. into the region between the eyelets 35 and 36, respectively, where the needles possess a certain spacing, then this turner thread gets with certainty to the other side of the needle, with the consequence that this turner thread can then assume the position required for the binding as prescribed.

The stationary threads drawn through the eyelets 35 and 36 always make an exact vertical movement.

The cross-weave or binding comes into being through the horizontal movement of the turner threads and the vertical movement of the stationary threads.

By giving the auxiliary rail a limited stroke substantial advantages are provided. It is attained through the arrangement of the auxiliary rail with oblique slot arranged crosswise with respect to the oblique slot means of the main rail, that the turner thread is guided more securely, because by the overlying arrangement of these oblique slots, there is formed an exactly defined opening in the shape of a hole which in the course of the motion of the auxiliary rail relative to the main rail is displaced towards the ends of the slot means and thereby securely entrains the turner thread.

A further advantage is that through the magnets which entrain the auxiliary rail after initiation of the reversing movement of the heald shafts, the end position of the turner thread in the slot is reached shortly after the start of the reversing motion of the heald shafts.

Relatively short working movements of the needle holder and thereby of the main rail are permitted since the reversal position of the turner thread is reached already shortly after the start of the reversing movement of the needle holder.

As a consequence of the premature attainment of the end position of the turner thread in the slot, the thread bears against the needle under tension so that it is guided with certainty to the other side on reaching the gap between the needles.

Claims

1. An apparatus for producing a fabric edge provided with a cross-weave, comprising a first and a second displaceable heald shaft, a needle holder connected to the first heald shaft, a main rail provided with oblique slot means and connected to the second heald shaft, an auxiliary rail connected to the main rail and having a limited displacement relative to the main rail and provided with oblique slot means disposed crosswise with respect to the slot means of the main rail, the displacement of the auxiliary rail being dependent on displacement of the needle holder.

2. An apparatus as claimed in claim 1, wherein the needle holder is provided with magnet means facing the auxiliary rail.

3. An apparatus as claimed in claim 2, wherein the auxiliary rail comprises spring tongue means facing the magnet means.

4. An apparatus as claimed in any one of the preceding claims, wherein the main rail and the auxiliary rail are connected with each other by pins extending through elongate openings in the auxiliary rail to allow the relative displacement between the main rail and the auxiliary rail.

5. An apparatus as claimed in any one of the preceding claims, wherein the auxiliary rail has a stroke, the length of which is adapted to the length of the slot means.

6. An apparatus as claimed in any one of the preceding claims, wherein each oblique slot means comprises two slots inclined to each other.

7. An apparatus as claimed in claim 1, comprising magnet means to influence guidance of the auxiliary rail during its displacement.

8. An apparatus as claimed in claim 7, wherein the needle holder comprises mutually parallel frame rails disposed to guide the main and auxiliary rails therebetween.

9. An apparatus as claimed in either claim 7 or claim 8, wherein the frame rails each have a channel-shaped cross-section as a guide groove for the auxiliary rail and the main rail.

10. An apparatus as claimed in any one of claims 7 to 9, wherein the main rail is provided with abutments to limit displacement of the auxiliary rail.

11. An apparatus as claimed in any one of claims 7 to 10, the magnet means being mounted to the auxiliary rail.

12. An apparatus as claimed in any one of claims 7 to 10, the magnet means being mounted to the frame rails.

13. An apparatus as claimed in any one of claims 7 to 12, comprising strip means connecting the main rail with the heald shafts.

14. An apparatus as claimed in claim 13, wherein the strip means comprises a metal.

15. An apparatus as claimed in claim 13, wherein the strip means comprises plastics material.

16. An apparatus substantially as hereinbefore described with refrence to Figures 1 to 4 of the accompanying drawings.

17. An apparatus substantially as hereinbefore described with reference to Figures 5 to 9 of the accompanying drawings.