GB2050442A - Automatic Weaving Loom - Google Patents

Abstract

A weft insertion element 9, mounted at one end on a support which is rectilinearly reciprocable along a guide 4, takes the weft thread through the shed to an interweaving needle 12. The free end of the element 9 has an eye 10 and is tapered. <IMAGE>

Description

SPECIFICATION Automatic Weaving Loom This invention relates to automatic weaving looms.

Starting from the process of inserting the weft in the shed by means of rectilinear reciprocating movement, it has been possible to obtain, by means of simple mechanisms, speeds which are much greater than those which may be obtained with other known mechanisms, providing superior quality and a considerable increase in efficiency in respect of other known systems.

The insertion of the weft threads(s) in the shed and the introduction of at least one auxiliary thread enables a series of binding actions to be carried out, these being necessary to cover the range of textiles which the present market requires. In respect of the looms for automatically weaving strips, it is possible, by inserting the weft by means of a rectilinear movement of a weft insertion element, to satisfy the above described requirements by means of a set of components which enable the achievement of high speeds with a minimum number of mechanisms, which thus reduces the maintenance of the loom to a minimum both in respect of its mechanical parts and the synchronisation of its elements, when a change of material and/or the packet of the weft thread(s) is required.

In order to obtain suitable speeds for shuttleless looms, with weft insertion by means of a rectilinear reciprocating movement, these looms are usually provided with two rod-shaped elements which move, with a rectilinear reciprocating movement and from both sides, in such a way that one of these elements inserts, by means of a gripper, the weft thread in the shed to slightly beyond the centre of the weave, and that the other elements takes up the weft thread at this point; during the withdrawal of the two elements, the weft thread is passed through and inserted in the entire shed.

Weft insertion systems are also known which pass through the shed by means of two elements which are displaced in opposition to one another and cooperates to form a curve. There is also the weft insertion system which passes through the entire shed also with a movement of curvature.

The present invention provides a loom which enables, by means of a rectilinear reciprocating movement, the insertion of the weft thread(s) in the shed by means of a special element of a shape enabling itself, or the weft thread(s), to be drawn or inserted into the entire shed, simplifying the required mechanisms to a great extent. The weft insertion element has at its free end an eye and forms an angle from this eye such that the introduction of the shed is carried out progressively.

Rectilinear movement is preferred because it requires a minimum displacement of the beating comb and consequently a lower shed, avoiding excessive angles and tensions. At the same time, with the rectilinear movement of the weft insertion element, the thread may be maintained at a constant tension, as it is not required to describe a curved path.

The weft thread is preferably supplied from a feed device which delivers it at a uniform tension, with a breakage detector, and conveyed through an adjustable tensor to a compensating mechanism provided with a breakage detector, and a recovery mechanism, so that the thread is always woven at the same tension.

In respect of the preferred features of the weft insertion element, the free end is designed to form an angle so that the separation of the warp is carried out progressively by working constantly along the line of greatest aperture of the shed, and as a result of this preventing possible breakages of the warp threads, in the case that any of these are not at the required tension.

The invention will be described further, by way of example with reference to the accompanying drawings.

Figure 1 shows diagrammatically part of an automatic loom including a weft insertion device, at least one needle, and actuating means; Figure 2 shows diagrammatically part of an automatic loom including a device having at least one weft insertion needle, in which the formation of a point edge may be carried out by means of a hook needle acting on an auxiliary thread. It is also possible to equip the device with two weft insertion needles and to use two hook needles and two auxiliary threads.

These variants may be carried out with a minimum of adjustment of the corresponding mechanisms, which are located in an accessible manner in order to simplify the operation.

Figure 1 shows in diagrammatic form a shuttleiess loom for automatically producing strips, in which only the components relevant to the present invention are shown for simplicity of representation. Reference numeral 1 represents a woven strip, and reference numeral 2 represents the warp threads forming the shed.

A weft insertion device 3 having an insertion element 9 is displaced with a reciprocating rectilinear movement along fixed guides 4 by means of articulated levers 5, 6, 7 driven by a cam 8 which, in its turn, is actuated by a drive shaft (not shown). (The device 3 may have more than one element 9.) The free end of the weft insertion element 9 has an eye 10 through which a weft thread 11 is passed, this element being characterised in that it has the shape of a progressive acute angle so as to facilitate its introduction into the shed and to ensure the transfer of the weft thread (and an auxiliary thread, if present) to a hook needle 12.

When the weft insertion element 9 is introduced at the edge of the weave, the weft thread is conveyed to the field of movement of the hook needle 12, this movement being synchronous with that of the element 9 and being carried out by means of articulated levers 13, 14, 15,16,17, 18drivenbyacam 19whichis powered by a drive shaft (not shown), and the hook needle 12 receives the weft thread 11 to form the woven cloth. In the same way the comb 20, by means of levers 21,22 and a cam 23 (which is actuated by a drive shaft, not shown), beats the various weft threads.

Operation of the loom for automatically weaving strips will now be described. With reference to Figure 1, when the weft insertion element 9 of the device 3 has engaged the weft thread 11 with the shed 2, the comb 20 is at the greatest distance from the beating edge of the weave. When the weft thread is in the field of operation of the hook needle 1 2 (the movements being perfectly synchronised) and when its return movement is initiated, it collects the weft thread in a known way and conveys it to form the cloth in this way. At the same time, the insertion element 9 returns to its initial position by means of a rectilinear movement, the bearing comb 20 beats the various weft threads and carries out the shed change, this being repeated in a new cycle.

In order to facilitate and ensure the accurate transfer of the weft thread to the hook needle, there are provided a plurality of adjustment points 24, 25, and 26, which enable the operation to be accelerated or slowed down by means of a minimum amount of displacement.

In order to achieve the high speeds obtained by means of the simple components which make up the main mechanical parts, research has been carried out into materials used, and the equilibrium of the moving masses in order to prevent any vibration.

Figure 2 shows in diagrammatic form a loom for weaving strips in which the point edge may be formed with at least one auxiliary thread. At least one weft insertion element 9 of an insertion device 3 is displaced, as in Figure 1, by means of a reciprocating rectilinear movement on guides 4 by way of articulated levers 5, 6, 7, displaced by a cam 8 which, in its turn, is displaced by a drive shaft (not shown).

The weft insertion element 9 may be displaced along the device 3 in a longitudinal direction, in order to advance its position so as to obtain the required synchronism for the introduction of an auxiliary thread 27.

The auxiliary thread 27, introduced in this way into the hook needle 12, is fastened to the needle in a known way.

The weft insertion element 9 is moved forward 3mm in respect of the hook needle 12, in order to catch the auxiliary thread 27 which is introduced by means of an eye 28 in a component 29 which is displaced towards the field of operation of the hook needle 12 by way of the shaft 30 by means of a drive means (not shown). The hook needle 12 collects the auxiliary thread 27, and passes it through the weft thread 11, thus forming the binding, all this being carried out by means of the accurate synchronisation of movement, in respect of which the mode of operation is basically the same as shown in Figure 1.

Claims (9)

Claims

1. An automatic weaving loom comprising a weft insertion element mounted at one end on a support which is reciprocable along a guide, and an interweaving needle, the free end of the weft insertion element having an eye and being tapered.

2. A loom as claimed in claim 1, in which the support is rectilinearly guided.

3. A loom as claimed in claim 1 or 2, in which the reciprocation of the support is carried out by means of articulated members and a cam.

4. A loom as claimed in any of claims 1 to 3, in which the weft insertion element is adjustable longitudinally relative to the support.

5. A loom as claimed in any of claims 1 to 4, in which the needle is reciprocated by means of articulated members and a cam.

6. A loom as claimed in claim 5, in which the connections of the members and the cam are adjustable to the movement of the needle.

7. A loom as claimed in any of claims 1 to 6, including a comb reciprocated by articulated members and a cam.

8. A loom as claimed in any of claims 1 to 7, in which the needle is arranged to catch an auxiliary thread conveyed into its field of operation by means of an eye in a reciprocating member.

9. An automatic weaving loom substantially as described with reference to, and as shown in, the accompanying drawings.