EP2505702B2 - Heald which comprises sections with multiple film layers - Google Patents

Description

The invention relates to a heddle for a heald frame of a weaving machine. In a heald shaft of a weaving machine, a large number of healds are arranged, each of which serves to receive a warp thread. By moving the heald frames up and down, a shed is opened into which a weft thread can be inserted. Weaving machines have several heald shafts. Therefore, some warp threads run through the thread eyes of the healds of a heald frame, while other warp threads run through the gaps between two adjacent healds when they are guided through healds of another heald frame.

In today's weaving machines, the heald frames move between the two reversal points at great speed, which requires great acceleration of the heddle frames. This places high demands on the healds. On the one hand, they must be sufficiently stable and have as long a service life as possible despite the relative movement to the warp threads. In addition, healds that are as light as possible are desired in order to keep the total weight of the heddle shaft to be accelerated with the large number of healds as low as possible.

Out of DE 43 36 362 C1 a heald is known which has a heald body which can be stamped out of metal or plastic. The area of the thread eye is twisted or twisted out of the plane in which the rest of the heald body extends, and in addition the two longitudinal webs delimiting the thread eye are interlaced.

Another heald made of plastic is from the EP 2 224 046 A1 known. This plastic heald is characterized by a special design of the guide surfaces in the area of the thread eye.

Next revealed the DE 10 2005 030 632 A1 a plastic heald whose thread eye is delimited by two laterally offset webs. Thickened ramp-like areas adjoin the thread eye at the top and bottom, which serve to keep adjacent healds at a distance and to allow warp threads running between two adjacent healds to slide gently on the outer surface.

In addition, healds are also known which have a heald body made of a flat metal strip, for example made of U.S. 5,348,055 . In CH 601 532 it is also proposed to attach end eyelets made of plastic to a metallic heald body part.

one out EP 1 795 636 A1 well-known heddle has a heddle body which consists of two flat tapes attached to each other. The tapes are spaced apart in the thread eye area and pins are inserted between the spaced tape sections to form the thread eye.

U.S. 5,005,608 describes a split strand made of two bands. These bands are only connected at one end and otherwise fit loosely against each other. To insert a warp thread, the two tapes can be separated from one another and the warp thread inserted between them up to a thread eyelet. The thread eyelet is formed by a recess in each band and a groove-like bulge adjoining the respective recess. Lay the bands touch each other, the bulge of one band engages in the recess on the other band and a thread eye is formed in the plane of the contact surfaces between the bulges.

Proceeding from this, it can be seen as an object of the present invention to create a heald that can be manufactured easily and has a long service life.

This object is achieved by a heddle having the features of patent claim 1.

The heald has a heald body which extends in the longitudinal direction and has a thread eyelet for receiving the warp thread. Preferably, the heddle body itself also has end eyelets with which the heddle can be arranged on a heddle support rail of the heald frame. In a reinforcement section, the heddle body has at least two foil layers or is formed by the foil layers which lie flat against one another and are connected to one another. The film layers are connected in particular by means of a material connection, for example by gluing. It is also possible to provide one or more inner foil layers in the reinforcement section, which are sandwiched between two outer foil layers. The heald may have one or more reinforcement sections in the longitudinal direction. The reinforcement sections can be spaced apart from one another or directly adjoin one another. It is also possible to construct the entire heald body with several continuous foil layers in the longitudinal direction.

It is therefore possible to manufacture the heald body from a film-like, thin material that is at least the reinforcement sections is strengthened by additional layers of film. An inner film layer can, for example, be arranged continuously in the longitudinal direction of the heddle body and ensure the necessary tensile strength of the heddle body. For example, in the area of the thread eye, this inner foil can be reinforced by attaching one or more additional foil layers in order to improve the resistance of the heddle body to being cut by a warp thread. The material of the different film layers is chosen to match the desired properties.

In a preferred embodiment, the individual film layers consist of a plastic material. The plastic material can also serve as a plastic matrix to which additional elements such as fibers, spheres or other bodies are added, resulting in a plastic-based composite material. The additional elements can be made of glass, ceramic or metal.

The plastic or composite material can be electrically conductive or have electrically conductive components in order to prevent electrostatic charging of the plastic strand. In the position of use of the heddle, an electrical connection to at least one electrically conductive heddle support rail is established by its electrically conductive components in order to allow electrical dissipation via the heddle support rail of the heddle shaft and thereby prevent static charging of the heald body. It is possible for the entire strand body of the plastic strand to consist of electrically conductive plastic or composite material, or for only individual layers of a multi-layer strand body to be electrically conductive. For example, the electrically conductive layers or the stranded body can consist entirely of composite material that contains a non-electrically conductive plastic matrix, which is connected to electrically conductive additional elements, for example made of metal and/or graphite. For example, long fibers and/or so-called whiskers and/or nanotubes or the like can serve as additional elements.

In one embodiment, the heald body can be provided with a metal layer on its two flat sides, at least in sections and/or in the area of the thread eyelet, on the outer surface. This reduces wear on the heald body, particularly in the areas of contact with the warp threads. The metal layers can be electrically connected to one another and, when the stranded wire is in its position of use, can produce an electrical connection to at least one electrically conductive stranded wire support rail.

The heald body can have a greater thickness in the at least one reinforcement section than in the sections adjoining the reinforcement section, which can be referred to as connecting sections. According to the invention, the number of film layers in the reinforcement section is greater than in the connection section. In one embodiment, it may be sufficient to produce the connecting section in just one layer from a single film layer, while this film layer is reinforced in the at least one reinforcement section by at least one additional film layer. This makes the heald very light and the use of material is limited to those areas where reinforcement of the heald body is necessary. This is in particular the area for guiding the warp thread around the thread eyelet and/or the end areas around the end eyelets. The thickness of the film layers arranged one on top of the other in a reinforcement section can be different. For example, a central foil layer can have a greater thickness to produce tensile strength, as an outer film layer arranged on top of it, which protects the heald body from being cut in by a thread. The thickness of a film layer is measured at right angles to its plane of extension.

The heddle described is produced by providing at least a first film web and a second film web. To form the at least one reinforcement section, the two foil webs are placed one on top of the other and connected to one another, for example by gluing or another type of material connection. Alternatively, the film webs can also be connected to one another directly during their production process step, for example by means of coextrusion of the multi-layer web. To increase the strength of the multi-layer web, it can be stretched in its extension plane in the direction of the web and/or transversely thereto in the width direction. The molecular structures are aligned and the strength in the direction of stretching is increased. It is also possible to stretch one or more of the film layers and then combine them to form a multi-layer web.

In this way, a multi-layer web is formed, at least in the reinforcement sections. The heald body is then separated from this web, which is multi-layered at least in sections, for example by being punched out. The heald body is thus designed as a separating part or stamped part. The end eyelets and the thread eyelet can be punched out first. At the same time or subsequently, the outer contour of the heddle body is punched out. In this way, a multiplicity of heald bodies can be punched out of a multi-layer web.

As an alternative to punching, the heald body can also be made from be cut out of the multi-layer web, for example by laser or ultrasonic cutting.

In a preferred embodiment, the cut or punched-out heald body is not processed further, but represents the finished heald. Alternatively, depending on the stiffness of the heald body, it may be necessary, for example, to remove the central longitudinal section around the thread eyelet from the plane of extension in which the punched-out heald body extends, to unscrew or twist, since the direction of the warp thread is oriented approximately at right angles to the course of the heddle support rails. In the case of very thin heddle bodies with little torsion resistance, the warp thread twists the thread eye in the position of use. With very sensitive threads, however, it may be necessary to plastically deform the thread eye area in order to reduce the force exerted on the warp thread by the torsional moment of the heald body . With such healds, after the heald body has been severed, the longitudinal section is twisted in the area of the thread eyelet and plastically deformed, for example, by thermal action, so that it remains in this position.

• Fig. 1 eine stark schematisierte Darstellung einer nicht erfindungsgemäßen Weblitze in Seitenansicht auf die Endösen und das Fadenauge,
• Fig. 2 eine schematische perspektivische Darstellung einer mehrlagigen Bahn, aus der der Litzenkörper nach Fig. 1 ausgestanzt werden kann,
• Fig. 3 ein weiteres Ausführungsbeispiel einer nicht erfindungsgemäßen Weblitze in stark schematisierter Seitenansicht auf die Endösen, wobei der Längsabschnitt im Bereich des Fadenauges tordiert ist,
• Fig. 4 eine teilgeschnittene Darstellung des Fadenauges quer zur Längsrichtung der Weblitze nach Fig. 3 gemäß Schnittlinie IV-IV,
• Fig. 5 eine Ausführungsform einer erfindungsgemäßen Weblitze in schematischer Ansicht auf die Flachseite in der Erstreckungsebene der Folienlagen und
• Fig. 6 eine Ausführungsform eines Verstärkungsabschnitts der erfindungsgemäßen Weblitze im Bereich eines Fadenauges mit mehreren inneren Folienlagen und zwei äußeren Folienlagen.

In the following, the heddle and the manufacturing method are explained using exemplary embodiments. Further advantageous configurations result from the description and the dependent patent claims, in which case the drawing is to be used as a supplement. Show it:

• 1 a highly schematic representation of a heald not according to the invention in a side view of the end eyelets and the thread eyelet,
• 2 a schematic perspective view a multi-layer web from which the heddle body is made 1 can be punched out
• 3 a further exemplary embodiment of a heald not according to the invention in a highly schematic side view of the end eyelets, the longitudinal section being twisted in the area of the thread eyelet,
• 4 a partially sectioned view of the thread eye transverse to the longitudinal direction of the heddle 3 according to cutting line IV-IV,
• figure 5 an embodiment of a heddle according to the invention in a schematic view of the flat side in the plane of extension of the film layers and
• 6 an embodiment of a reinforcement section of the heddle according to the invention in the area of a thread eye with several inner foil layers and two outer foil layers.

The drawing shows exemplary embodiments of a heddle 10 with a heald body 11 extending in a longitudinal direction L. The heald body 11 has a thread eye 12 for guiding a warp thread, which is arranged approximately centrally in the heald body 11 . An end eyelet 13 is provided on each of the two longitudinal ends of the heddle body 11 and is used for arranging the heddle on the heald support rails of a heald frame. In the exemplary embodiments explained here, the end eyelets 13 are shown as O-shaped end eyelets which are closed in the form of a ring. Alternatively, it is also possible to open the end loops laterally at one point to form C-shaped or J-shaped end loops.

The various embodiments of the heald 10 shown in the drawing are highly schematic and are not shown to scale. In the drawing, only the principle of the heald 10 according to the invention and its production are to be illustrated.

The heald body is constructed in multiple layers at least along a reinforcement section 15 extending in the longitudinal direction L. At least within the reinforcement section 15, the heddle body 11 consists of two or more film layers 16 which are laid flat on top of one another and connected to one another. The film layers 16 are bonded to one another over a large area, for example glued. The material connection is carried out over the entire surface along the entire contact surface between the film layers 16 lying against one another. Alternatively, different film layers can also be produced by coextrusion and connected to one another in one step, so that a subsequent joining process such as gluing can be omitted.

The number of foil layers 16 in a reinforcement section 15 can vary. There is preferably at least one central or inner film layer 16a sandwiched between two outer film layers 16b. In the exemplary embodiment, the at least one inner foil layer 16a is used to give the heald body 11 the necessary tensile strength. For this purpose, the thickness of the at least one inner film layer 16a, the number of inner film layers 16a, the material, etc. are selected accordingly. The entire heald body 11 is preferably made of plastic. The various film layers and in particular the inner film layers 16a and the outer film layers 16b can consist of different plastics. It is also possible to use composite materials based on plastic, with additional elements being added to a plastic matrix, which can consist of glass and/or ceramic and/or metal, for example. Such additional elements can be formed by short fibers (so-called whiskers) and/or spheres and/or other small bodies. However, a uniform material is used for each film layer.

In the reinforcement sections 15, the two outer foil layers 16b serve to increase the wear resistance of the heald body 11 in relation to the warp thread 19 and in relation to the heddle support rails. Therefore, in a preferred embodiment, at least three reinforcement sections 15 are provided. The two end eyelets 13 and the thread eyelet 12 are located in these three reinforcement sections 15 . Especially in the central reinforcement section 15 , the heald body 11 must be protected against being cut in by the warp thread 19 . In the position of use, the heald 10 is greatly accelerated and takes the warp thread guided in the thread eyelet 12 with it in order to bring it into the desired position to take a stand. Due to the high accelerations, relatively high forces also act between the warp thread 19 and the heddle body 11. For this reason, the two outer foil layers 16b around the thread eyelet 12 are made of a plastic or composite material that is particularly wear-resistant and ensures a long service life for the heddle 10 guaranteed. For example, polyethylene, polypropylene or polycarbonate can be used for the at least one inner film layer 16a. Polyamide, for example, can be used for the outer film layers 16b. The plastics mentioned can also be used as a plastic matrix in a composite material. For the production of the heddle body 11, foil webs are provided, which are connected to one another over a large area and then form a multi-layer web 17, as is shown in an example in 2 is shown. In this exemplary embodiment, the entire heald body 11 has a multi-layer design in its longitudinal direction L. The number of foil layers 16 is constant in the longitudinal direction L along the heald body. All foil layers 16 extend over the entire length of the heald body 11.

The heald body 11 is then severed from such a multi-layer film web 17 . The heddle body 11 is preferably punched out. The stamping process can take place in one or more steps. It is possible first to punch out the thread eyelet 12 and the end eyelets 13 from the film web 17 in a first punching process. The outer contour 18 can then be punched out. Alternatively, the punching processes can also take place simultaneously. After punching, a heald body 11 is obtained as a punched part, as shown schematically in 1 is shown.

Depending on the torsional stiffness of the heddle body 11, it may be necessary for the plane in which the thread eye 12 extends to twist relative to the plane in which the end eyelets 13 extend, as is the case with reference to FIG Figures 3 and 4 is illustrated. For this purpose, a central longitudinal section of the heald body 11 can be plastically deformed in order to fix the plane of the thread eyes relative to the plane of the end eyelets 13 in the twisted position. This makes it possible to guide a warp thread 19 through the thread eyelet 12 without the warp thread 19 being subjected to a torsional moment of the heddle 10 .

The foil layers 16 of the heald body 11 can be shorter than the heald body 11 viewed in the longitudinal direction L and can only be arranged in a reinforcement section 15 . In the transverse direction Q, transverse to the longitudinal direction L and in the extension plane of the film layer 16, all film layers 16 extend over the entire width of the heald body 11.

In contrast to the in the Figures 1 to 4 illustrated embodiments is in the embodiment of the heddle 10 after figure 5 the heald body 11 is of non-uniform thickness in the longitudinal direction L. It has a plurality of reinforcement sections 15 spaced apart in the longitudinal direction L, for example three. These are located in the two end areas on the end eyelets 13 and in the central area on the thread eyelet 12. The two end reinforcement sections 15 are connected to the central reinforcement section 15 via a connecting section 21 each. The number of film layers 16 is less in the connecting sections 21 than in the reinforcing sections 15. In the exemplary embodiment, the connecting sections are formed by only one central or inner film layer 16a. This inner film layer 16a extends in the longitudinal direction L continuously through the entire heald body 11. In the reinforcement sections the inner film layer 16a is reinforced by at least one further film layer and sandwiched, for example, by two outer film layers 16b arranged on opposite sides. In order to produce such a heddle 10, the multi-layer web 17 only has a plurality of foil layers at the points corresponding to the reinforcement sections 15 after the heald body 11 has been severed. The view of the front edge of such a film web 17 would correspond to the illustration in figure 5 are equivalent to.

The individual film layers 16 can have different thicknesses depending on their function and/or depending on the material used. A purely exemplary representation of film layers 16 of different thicknesses is shown in 6 sketched. In this exemplary embodiment, a plurality of inner film layers 16a are provided, each having a thickness da. All inner foil layers 16a extend in the longitudinal direction L along the entire heald body 11. The total thickness di therefore results from the thickness da of an inner foil layer 16a multiplied by the number of inner foil layers 16a provided. According to the example, five inner film layers 16a are provided here, the number of which can be selected according to the requirements. For example, depending on the application, the tensile strength of the heald 10 can be increased by increasing the number of inner film layers 16a. This enables healds 10 to be produced very flexibly and inexpensively, with production being able to be very easily adapted to different load cases.

In contrast, the thickness db of the two outer film layers 16b is smaller than the total thickness di of all inner film layers 16a and, for example, greater than the thickness da of a single inner film layer 16a. In a modification of this could on both sides of the heald body 11 respectively several outer foil layers 16b can also be provided.

The invention relates to a heddle 10, the heddle body 11 of which is constructed in several layers, at least in sections. The heald body 11 has at least one reinforcement section 15 which consists of a plurality of foil layers 16 . Preferably, at least one inner film layer 16a extends in the longitudinal direction L along the entire heald body 11. This at least one inner film layer 16a is in particular in the section around the thread eyelet 12 and/or in the section around the end eyelets 13 of the heald body 11 with at least one and preferably two outer Foil layers 16b to form reinforcement sections 15 reinforced. The reinforcement sections 15 can be constructed in a sandwich-like manner, so to speak, from preferably at least three film layers 16a, 16b. The result is a simple production by providing a multi-layer foil web at least in sections and cutting out or punching out the heald body 11 from this multi-layer foil web.

Reference list:

10

heald

11

strand body

12

thread eye

13

end loop

15

reinforcement section

16

film layer

16a

inner foil layer

16b

outer foil layer

17

film web

18

outer contour

19

warp thread

21

connection section

there

Thickness of the inner foil layer

db

Thickness of the outer film layer

you

Total thickness of all inner foil layers

L

longitudinal direction

Q

transverse direction

Claims (15)

1. Heald (10) for a heald frame,

   with a heald body (11) extending in a longitudinal direction (L) and having a thread eye (12) which serves to receive a wrap thread (19),

   wherein in at least one reinforcing portion (15), the heald body (11) comprises two film layers (16a, 16b) which lie flat against one another and are interconnected, characterized in that the film layers (16a, 16b) are interconnected by fully superficial substance bonding over the entire contact area, and that a connecting portion (21) of the heald body (11) adjoins the at least one reinforcing portion (15) of the heald body (11) having at least two film layers (16a, 16b), wherein the connecting portion (21) comprises fewer film layers (16a) than the adjoining reinforcing portion (15).
2. Heald according to claim 1, characterised in that at least three film layers (16) are provided in the reinforcing portion (15).
3. Heald according to claim 1, characterised in that the heald body (11) comprises several reinforcing portions (15), each with at least two film layers (16).
4. Heald according to claim 1, characterised in that the heald body (11) has only one film layer (16a) in the connecting portion (21).
5. Heald according to claim 1, characterised in that the entire heald body (11) has at least two film layers (16).
6. Heald according to claim 1, characterised in that at least one central film layer (16a) extends along the entire heald body (11) in the longitudinal direction (L).
7. Heald according to claim 6, characterised in that the central film layer (16a) is arranged between two outer film layers (16b) in the reinforcing portions (15).
8. Heald according to claim 1, characterised in that one film layer (16a) is made from a first material and at least one other film layer (16b) is made from a second material.
9. Heald according to claim 1, characterised in that the heald body (11) is made from a plastic material or composite material.
10. Heald according to claim 9, characterised in that the plastic material or composite material is electrically conductive or comprises electrically conductive constituents.
11. Heald according to claim 1, characterised in that the heald body (11) is provided with a metal coating on its outer surface on its flat sides, at least in portions and/or in the region of the thread eye (12).
12. Heald according to claim 1, characterised in that the thickness (da, db) of two film layers (16a, 16b) differs in one reinforcing portion (15).
13. Heald according to claim 1, characterised in that the length portion in the region of the thread eye (12) is twisted relative to the extent plane of the remaining heald body (11).
14. Heald according to claim 1, characterised in that a reinforcing portion (15) is present containing the thread eye (12).
15. Heald according to claim 1, characterised in that two reinforcing portions (15) are present containing the end eyelets (13).

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