EP0786547A1 - Process and device to form tuck-in selvedges - Google Patents

Abstract

The invention describes a method and a device for the pneumatic insertion of a weft end into a shed of a weaving machine. In a known manner, an insertion device is provided on each of the fabric edges, which interacts with a cutting device and which, after cutting off the weft thread, pneumatically inserts the weft thread ends into a shed following a shed. Each insertion device has at least two insertion heads (8, 9), the respective weft end being pneumatically gripped by the outside insertion head (9) and pneumatically transferred to the inside insertion head (8) which pneumatically inserts the weft end into the shed. <IMAGE>

Description

The invention relates to a method and a device for the pneumatic insertion of a weft end according to the preamble of patent claim 1 or 2.

Insertion devices on weaving machines are well known and are used to insert the free weft ends into the following shed after the insertion of the weft in the shed. This is often solved in that the weft end is gripped by the air flow from a blowing nozzle and blown back into the subsequent open shed. As a result, a so-called insert edge is formed on the edges of the fabric, the fabric being approximately twice as thick in this area. The insert edge has a width of a few to several centimeters.

Such insert edges are highly desirable depending on the intended use of the finished fabric, since z. B. for tarpaulins the reinforced fabric edge is ideal for attaching eyelets or the like. In connection with other applications, there was even a need to have the widest possible insertion edge, but this is difficult or impossible to achieve with the previous insertion devices.

The object of the present invention is to develop a method and a device for inserting a weft end in such a way that substantially wider insert edges can be achieved therewith.

This object is achieved by the characterizing part of claims 1 or 2.

An essential feature of the invention is that each pneumatically acting Insertion device not only has an insertion head, as is known hitherto, but at least two insertion heads which are arranged one behind the other in the weft direction of the thread.

Of course, a cutting device is provided at least on the side of the weft thread entry, which connects to the outer insertion head as seen from the fabric edge.

The arrangement according to the invention of a plurality of insertion heads arranged one behind the other means that, after the weft thread has been cut off, a relatively long weft thread end protruding beyond the fabric edge remains, the length of which corresponds approximately to the entire width of the insertion heads arranged in series. In order to insert the thread end into the subsequent shed, the outer insertion head, as seen from the fabric edge, first comes into action, which pneumatically grips the thread end and pneumatically transfers it to the inner insertion head, which finally pneumatically inserts the thread end into the shed.

The insertion device according to the invention makes it possible to insert a much longer thread end piece into the shed, so that a very wide insertion edge is formed. This increases the edge strength of the fabric, which is required in many applications, and saves the fabric processing companies from having to sew the fabric edges around, so as to simulate the insert edge.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but also from the combination of the individual patent claims with one another.

All information and features disclosed in the documents, including the summary, in particular the spatial depicted in the drawings Training are claimed as essential to the invention, insofar as they are new compared to the prior art, individually or in combination.

The invention is explained in more detail below with the aid of drawings which illustrate only one embodiment. Here, from the drawings and their description, further features and advantages of the invention that are essential to the invention emerge.

Figur 1:

eine schematische Darstellung einer Webmaschine in Draufsicht, wobei sich das Riet in seiner hinteren Stellung befindet;

Figur 2:

eine schematische Darstellung einer Webmaschine in Draufsicht, wobei sich das Riet in seiner vorderen Stellung befindet;

Figur 3:

ein vergrößerter Ausschnitt des linken Teils von Figur 2.

Show it:

Figure 1:

a schematic representation of a loom in plan view, the reed is in its rear position;

Figure 2:

a schematic representation of a loom in plan view, the reed is in its forward position;

Figure 3:

an enlarged section of the left part of Figure 2.

The drawing figures show an example of a weaving machine in which several fabric webs can be woven at the same time.

The reed 1 consists of several sections, the fabric streets, that is to say the areas in which no warp threads 7 are provided, each being filled with a fixed filler 2. One reed 1 and one filler piece 2 are therefore arranged in an alternating sequence, with the filler pieces 2 being arranged in line with the reed member 1 in the rear position of the reed member 1.

The fabric runs over a continuous spreader table 3, the warp threads 7 spanning a shed between the reed 1 and the spreader table 3.

A weft 5 is introduced into the shed via a main nozzle 4 and passes through this with the aid of auxiliary nozzles 6 until it arrives at the opposite side and is gripped by a stretching nozzle 13. A weft monitor 14 checks whether the weft 5 has arrived correctly. When the weft 5 has arrived and has been gripped by the stretching nozzle 13, the reed 1 moves together with the stretching nozzle 13 into its front stop position, so that the weft thread is struck against the fabric (FIG. 2).

At the edges of the fabric there are two insertion heads 8, 9, which, as seen in the weft direction of the thread 5, are arranged one behind the other. Beyond the insertion heads 8, 9 there is a cutting device 10 which, after the reed 1 is in its forward position, cuts off the weft 5.

The remaining remaining thread is disposed of by a suction device 12, the ends of the weft projecting above the fabric edges being inserted into a subsequent shed by the insertion device 8, 9.

The cutting devices 10 are located behind or in front of the outer insertion heads 9, so that the cut thread ends which protrude beyond the fabric edge have a length x (FIG. 3) which corresponds at least to the width of the insertion heads 8, 9 lying one behind the other.

If the thread 5 is cut, the respective outer end of the weft thread is pneumatically gripped by the outer insertion head 9 and pneumatically transported in the direction of the insertion head 8. The insertion head 8 now takes over the weft end and places it pneumatically in a subsequent shed, the insertion edge which has the previously defined length or width x.

When using two insertion heads 8.9 per insertion device, the width of the insertion edge can be doubled. Analogously, three or more insert heads lying one behind the other could also be used, so that a three or more widened insert edge could be produced.

With the method according to the invention and the associated device, widened insert edges can thus be produced in a simple manner and with existing and tested assemblies.

DRAWING LEGEND

1

Advised

2nd

Filling piece

3rd

Spreader table

4th

Main nozzle

5

Weft

6

Auxiliary nozzles

7

Warp threads

8th

Insertion head

9

Insertion head

10th

Cutting device

11

Insert edge

12th

Suction

13

Stretching nozzle

14

Gunner

Claims (4)

Method for inserting a weft end into a shed of a weaving machine, wherein a pneumatically acting insertion device is provided on the fabric edges, which interacts with a cutting device and, after the weft has been cut off, inserts the remaining weft end into a subsequent shed, characterized in that each insertion device has at least one has two insertion heads (8, 9), the weft end being pneumatically gripped by the outside insertion head (9) and pneumatically transferred to the inside insertion head (8) which pneumatically inserts the weft end into the shed. Insertion device for the pneumatic insertion of a weft end into a shed of a weaving machine, the insertion device being provided in each case on the fabric edges and at least one insertion device cooperating with a cutting device, and after cutting off the weft thread, the remaining weft end is pneumatically inserted into a subsequent shed, characterized in that each Inserting device has at least two insertion heads (8,9). Insertion device according to claim 2, characterized in that the insertion heads (8, 9) are arranged one behind the other as seen in the firing direction, with an outside insertion head (9) and an inside insertion head (8) Insertion device according to claim 2 or 3, characterized in that a cutting device is provided which is arranged outside the outer insertion head (9)

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