EP2059633B1 - Ribbon needle loom - Google Patents

Abstract

In order firstly to make a high speed possible but also to avoid high peak values of the weft thread tension in the process in a needle loom having a weft-thread compensation device (22) which tensions the weft thread (4), it is proposed to configure the weft-thread compensation device (22) as an air stream device and, furthermore, to use a spring device (12) for measuring and/or for limiting the weft thread tension.

Description

Technical area

The invention relates to a needle ribbon loom according to the preamble of claim 1.

State of the art

Needle ribbon looms of the type mentioned are known in many forms, such as de WO-A-96/19604 , The ribbon loom comprises a weft insertion needle, which is associated with a weft feeder, the - viewed in the direction of weft - a weft source, a weft brake, a weft conveyor and a pneumatically operated, designed as blowing or suction weft compensation device and before Weft insertion needle has a separate weft thread guide eye. Older needle looms, however, have a weft compensating device, which is typically formed by a leg spring, such as from CH-646 397 A5 known. While the needle looms with a leg spring device typically limited to low speeds and thus - as in the WO-A-96/19604 described in detail - are basically limited in their performance, it has been found in connection with the formed as a blowing or suction weft compensation device that the weft tension without high measures at weft insertion has high peaks, as in illustration 1 is shown. This may be disadvantageous in certain designs of a needle loom, especially when there is a risk that the peak values of the weft tension during weft insertion cause a high weft load at most associated with a tearing of the weft. Although these high peak values of the weft tension usually do not occur in the conventional weft compensating device with a leg spring, as seen from FIG. 2 evident. However, the weft tension when using a weft compensating device with a leg spring due to the low bandwidth of the spring is very different Values on, as also off FIG. 2 shows what just leads to the above-described limitation of the speed.

Presentation of the invention

The object of the invention is to improve a needle loom of the type described above.

The object is achieved by a needle loom according to claim 1. The measures of the invention initially have the consequence that a Nadelbandwebmaschine is provided, the weft supply on the one hand has a high control bandwidth and therefore allows a high speed, but in which large fluctuations in the weft tension can be avoided, as in FIG. 3 is shown. Furthermore, a measured value and a limitation possibility for the weft thread tension are available, which can be advantageously used during operation of the needle ribbon loom.

Advantageous embodiments of the reed device are described in claims 2 to 8.

It is advantageous according to claim 2, when the guide eye of the spring device between the weft yarn transport device and the weft yarn equalizer is arranged.

It is advantageous in the sense of an extended possibility for designing the needle ribbon loom if the limiting values of the weft thread tension can be set by the spring device according to claim 3.

In principle, the measured values of the spring device can be used to display or output a warning when the limiting values are exceeded or fallen short of. In a needle loom, which is operated at high speed, but it is advantageous if the spring device is coupled to a drive device of the needle loom. According to claim 4 the drive is interrupted if the limit values of the weft tension are exceeded or exceeded.

Structurally, it is advantageous if according to claim 5, the spring means comprises a coil spring which is connected to a compensation pin or a plunger on which the guide eye is arranged. It may be advantageous to adjust the delivery rate of the weft conveyor by the position of the compensation pin controllable and to regulate accordingly.

Structurally, it is also advantageous if the known from the prior art, further guide eyelet, which is arranged between the pneumatic weft compensating device and the weft insertion needle, according to claim 7 is further maintained.

Especially for this application, the pneumatic weft compensating device according to claim 8 can be used in a further developed form. This has a limited by sidewalls flow channel for the passage of air flow and the inclusion of a weft thread loop, wherein in at least one side wall in the flow direction of the air flow behind one another several air nozzles are arranged like a relay. This makes it possible to adjust the weft balancing device to different types and / or thicknesses of the weft.

Advantageously, in this case - according to claim 9 - the distance of opposing side walls of the flow channel adjustable.

The above-mentioned as well as the claimed and described in the following embodiments, according to the invention to be used elements are subject to their size, shape design, material usage and their technical conception no special conditions of exception, so that the well-known in the respective field of application selection criteria can apply without restriction.

Brief description of the drawings

Figur 1

ein Diagramm der Schussfadenspannung im Betrieb einer herkömmlichen Nadelbandwebmaschine mit einer pneumatisch arbeitenden, als Blas- bzw. Saugeinrichtung ausgebildeten Schussfaden-Ausgleichsvorrichtung;

Figur 2

ein Diagramm der Schussfadenspannung im Betrieb einer älteren Nadelbandwebmaschine mit Schenkelfeder zum Schussfaden-Ausgleich;

Figur 3

ein Diagramm der Schussfadenspannung im Betrieb einer Nadelbandwebmaschine gemäss der vorliegenden Erfindung;

Figur 4

eine schematische Darstellung der Schussfadenführung beim Anschlag eines Schussfadens;

Figur 5

eine schematische Darstellung der Schussfadenführung beim Eintrag eines Schussfadens in ein Webfach; und

Figur 6

eine schematische Darstellung der Verschiebbarkeit der Seitenwände des Strömungskanals der Schussfaden-Ausgleichseinrichtung aus Figur 4 und 5.

Exemplary embodiments of the invention will be described in more detail below with reference to schematic drawings, in which:

FIG. 1

a diagram of the weft tension during operation of a conventional needle loom with a pneumatically operated, designed as blowing or suction weft compensation device;

FIG. 2

a diagram of the weft tension during operation of an older needle loom with leg spring for weft compensation;

FIG. 3

a diagram of the weft tension in the operation of a needle loom according to the present invention;

FIG. 4

a schematic representation of the weft yarn guide when attacking a weft thread;

FIG. 5

a schematic representation of the weft yarn guide when entering a weft thread in a shed; and

FIG. 6

a schematic representation of the displaceability of the side walls of the flow channel of the weft compensating device FIG. 4 and 5 ,

Ways to carry out the invention

The FIGS. 4 and 5 show essential components of the weft feeder of a needle loom in the schematic representation in the manner of a block diagram in two different operating states of the weft insertion needle.

The weft supply shown starts with the shot cone 2, from which the weft thread 4 is withdrawn. The weft thread 4 is then guided by means of two pressure rollers 6 and 6 'on a transport roller 8 and supplied from this to the other components of the weft thread guide. As the next component is located in the path of the weft thread 4, the spring means 12 for measuring and / or limiting the spring force, the real heart of the invention, in cooperation with a pneumatically operating weft equalizer 22, which is designed as an air flow device.

The spring device 12 comprises a linear spring 14, which is connected on one side via a compensation pin 15 with a guide eye 16 for the weft thread 4. On the other side, the spring 14 is firmly attached to the spring housing. The spring device 12 has two end position sensors 18 and 20, each of which emits a signal when the end position is reached. In the exemplary embodiment, the end position sensors 18 and 20 as electrical sensors - switch - are formed. In an alternative embodiment, the end position sensors are designed as optical sensors. In the embodiment described here, the deflection of the spring 14 is very small. The spring causes the weft so primarily a change in voltage, while in the embodiment described here, the length compensation is effected almost exclusively by the weft equalizer 22.

The operation of the spring device 12 will be described below. The compensation pin 15 is horizontally movable by a few centimeters. This coupled with the spring 14 compensation pin 15 is positioned during operation of the loom and shows the weaver in which position which forces exist. When the compensation pin 15 is pulled completely forward by the weft thread 2 - ie toward the weaver (here to the left), an increased force acts on the thread, which must be readjusted at best by regulation of the drive of the transport roller 8. The readjustment, which can be carried out manually or automatically, for example by means of a control electronics, allows the compensation pin 15 to settle in the most advantageous position. The position of the compensation pin 15 at the very back means too loose thread. In both End positions front and rear, the machine is also stopped in the present embodiment. In an alternative embodiment of the invention, a position monitoring of the compensation pin 15 is provided over its entire possible path.

By the solution with the spring device 12 and the compensation pin 15, the number of revolutions of the weaving machine can be easily increased to 3,000 revolutions per minute or more. It should be emphasized that in the embodiment described here the position of the spring 14 remains essentially unchanged due to its inertia during the weaving process. Thus, the spring does not participate in the movement - except in the start / stop phase - but passes on its defined tension in the end positions to the weft thread.

The weft thread 4 extends from the spring device 12 further to the weft equalizer 22. The weft equalizer 22 has a flow channel defined by side walls for the passage of an air flow and the reception of a weft thread loop. In the embodiment, five air nozzles 24 are arranged like a relay in a side wall in the flow direction of the air flow one behind the other, which provide a uniform tension of the weft thread. The flow channel - made of aluminum in the embodiment described here - can ensure a constant volume of air. A side wall 25 forming the flow channel-made of sheet steel in the exemplary embodiment described here-can, as in FIG FIG. 6 shown, at a distance a = 0.3 to 1.8 mm to the opposite side wall 25 'to be moved. As a result, the weft compensating device 22 can be adjusted to different thread thicknesses and thread qualities, and thus also the tension force exerted on the weft thread. With the weft equalizer 22 described herein, a memory effect is enabled with a constant volume of air. Alternatively, a plastic version of the central air block and the side plate can be provided. This is advantageous in terms of noise reduction, especially with thicker threads.

In the course of the weft thread this is supplied in the present embodiment via a guide and Umlenköse 26 of the weft needle 28, the weft 4 with open shed and position of the reed 32 - as in FIG. 5 shown - between the warp threads 34 einschiesst.

This weft thread control used in the exemplary embodiment described here with the spring device 12 and the weft-compensating device 22 prevents drawn, wavy strip edges caused by excessive edge tensions of the weft threads. Another advantage is illustrated by the following numerical example. On a machine designed for 50 mm belts, it is readily possible to weave a belt with a width of only 15 mm. Due to the air volume solution, there is always enough thread reserve.

LIST OF REFERENCE NUMBERS

a

distance

2

shot cone

4

weft

6

pressure roller

6 '

pressure roller

8th

transport roller

12

spring means

14

feather

15

compensation pin

16

guide eye

18

Endstellungssensor

20

Endstellungssensor

22

Weft compensating device

24

relay nozzles

25

Side wall

25 '

Side wall

26

guide eyelet

28

Weft insertion needle

30

reed

32

warp

Claims (9)

1. A ribbon needle loom, with a weft insertion needle, which ribbon needle loom is assigned to a weft thread feeding device (2) with a weft thread transport device (6, 6', 8) and with a weft thread compensation device (22) tensioning the weft thread, the weft thread compensation device (22) being designed to operate pneumatically as an air stream device, characterized by a spring device (12), having a guide eye (16), for measuring and/or limiting the weft thread tension.
2. The ribbon needle loom as claimed in claim 1, characterized in that the guide eye (16) of the spring device is arranged between the weft thread transport device (6, 6', 8) and the weft thread compensation device (22).
3. The ribbon needle loom as claimed in claim 1 or 2, characterized in that the limit values of the weft thread tension can be set by means of the spring device (12).
4. The ribbon needle loom as claimed in one of claims 1 to 3, characterized in that the spring device (12) is coupled to a drive device of the ribbon needle loom in such a way that the drive is interrupted when the limit values of the weft thread tension are undershot or overshot.
5. The ribbon needle loom as claimed in one of claims 1 to 4, characterized in that the spring device (12) has at least one helical spring (14) which is connected to a compensating pin (15) or a tappet on which the guide eye (16) is arranged.
6. The ribbon needle loom as claimed in claim 5, characterized in that the conveying quantity of the weft thread transport device (6, 6', 8) is regulated by means of the position of the compensating pin (15).
7. The ribbon needle loom as claimed in one of claims 1 to 6, characterized by a further guide and deflection thread eye (26) which thread eye is arranged between the weft thread compensation device (22) and the weft insertion needle (28).
8. The ribbon needle loom as claimed in one of claims 1 to 7, characterized in that the weft thread compensation device (22) has a flow channel, delimited by side walls, for the passage of an air stream and for the reception of a weft thread loop, a plurality of air nozzles (24) being arranged, staggered, one behind the other in the flow direction of the air stream in at least one side wall.
9. The ribbon needle loom as claimed in claim 8, characterized in that the distance (a) between mutually opposite side walls (25, 25') of the flow channel is adjustable.

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