EP2505702B1 - Heald which comprises sections with multiple film layers - Google Patents

Description

The invention relates to a heddle for a weaving shank of a loom. In a loom of a loom, a plurality of strands are arranged, which serve to receive a respective warp thread. By moving the heald up and down, a shed is opened into which a weft thread can be inserted. Looms have several healds. The one warp threads therefore pass through the thread eyes of the strands of a heald, while other warp threads pass through the spaces between two adjacent strands when passed through strands of another heald.

In today's weaving machines, the healds move at great speed between the two reversal points, which requires large accelerations of the heald frames. This makes high demands on the healds. On the one hand, they must be sufficiently stable and, in spite of the relative movement to the warp threads, have the largest possible service life. In addition, as light as possible healds are desired to keep the accelerated total weight of the heald with the plurality of healds as low as possible.

Out DE 43 36 362 C1 For example, a heddle is known which has a heddle body which may be stamped out of metal or plastic. The area of the thread eye is rotated or twisted out of the plane in which the rest of the strand body extends, and in addition the two longitudinal webs delimiting the thread eye are entangled.

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

Next discloses the DE 10 2005 030 632 A1 a plastic heddle whose thread eye is bounded by two laterally staggered webs. Above and below close to the thread eye thickened ramp-like areas, which serve to keep adjacent healds at a distance and to let gently slide between two adjacent healds warp on the outer surface.

In addition, healds are known which have a strand body made of a flat metal strip, for example US 5,348,055 , In CH 601 532 It is also proposed to attach plastic end lugs to a metal strand body part.

One out EP 1 795 636 A1 Known strand has a strand body, which consists of two surface-mounted bands. The bands are spaced apart in the Fadenaugbereich and between the spaced band sections pins are used to form the thread eye.

US 5,005,608 describes a split strand of two bands. These bands are connected only at one end and are otherwise loosely attached to each other. To insert a warp thread, the two tapes can be separated from each other and the warp thread between them can be used up to a thread eye. The thread eye is formed by a respective recess in each band and a subsequent to the respective recess groove-like bulge. If the bands touch each other, the bulge of one engages Bandes in the recess on the other band and it is formed in the plane of the contact surfaces between the bulges a thread eye.

With this in mind, it can be considered an object of the present invention to provide a heald which is easy to manufacture and has a long service life.

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

The heddle has a longitudinally extending strand body which has a thread eye for receiving the warp thread. The heddle body itself preferably also has end-side end loops with which the heddle can be arranged on a heddle support rail of the reef. The stranded body has at least two foil layers in a reinforcing section or is formed by the foil layers, which lie flat against one another and are connected to one another. The bonding of the film layers is effected in particular by a cohesive connection, for example by gluing. It is also possible to provide in the reinforcing section one or more inner layers of film which are sandwiched by two outer layers of film. The heddle may have one or more longitudinal reinforcing sections. The reinforcing portions may be spaced from each other or immediately adjoin one another. It is also possible to construct the entire strand body with several continuous film layers in the longitudinal direction.

Thus, a production of the strand body of a film-like thin material is possible, which is strengthened at least in the reinforcing sections by further film layers becomes. An inner film layer may for example be arranged continuously in the longitudinal direction of the strand body and provide the necessary tensile strength of the strand body. For example, in the area of the thread eye, this inner film can be reinforced by attaching one or more additional film layers in order to improve the resistance of the strand body to the cutting of a warp thread. The material of the different film layers is selected according to the desired properties.

In a preferred embodiment, the individual foil layers are made 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, so that a composite material based on plastic arises. The additional elements can be made of glass, ceramic or metal.

The plastic or composite material may be electrically conductive or have electrically conductive components in order to prevent electrostatic charging of the plastic strand. In the operating position of the strand is made by the electrically conductive components an electrical connection to at least one electrically conductive heald support rail to allow electrical discharge via the heddle support rail of the heald and thereby prevent static charging of the heald body. It is possible that the entire strand body of the plastic strand consists of electrically conductive plastic or composite material or that only individual layers of a multilayer strand body are electrically conductive. For example, the electrically conductive layers or the strand body as a whole may consist of composite material which contains a non-electrically conductive plastic matrix which is provided with electrically conductive additional elements for Example of metal and / or graphite is connected. As additional elements, for example, long fibers and / or so-called whiskers and / or nanotubes or the like can serve.

In one embodiment, the stranded body can be provided on its two flat sides, at least in sections and / or in the region of the thread eye, in each case on the outer surface with a metal layer. This reduces the wear of the strand body, especially in the contact areas with the warp threads. The metal layers may be electrically connected to one another and, in the position of use of the strand, produce an electrical connection to at least one electrically conductive heddle support rail.

The heddle body may have a greater thickness in the at least one reinforcing section than in the sections adjoining the reinforcing section, which may be referred to as connecting sections. According to the invention, the number of foil layers in the reinforcing section is greater than in the connecting section. In one embodiment, it may be sufficient to produce the connecting portion only in one layer from a single foil layer, while this foil layer is reinforced in the at least one reinforcing section by at least one additional foil layer. The heald is thereby very easily and the use of materials limited to the areas in which a reinforcement of the heald body is necessary. This is especially the area for the warp thread guide around the thread eye and / or the end areas around the end eyelets. The thickness of the foil layers arranged one above the other in a reinforcing section can be different. For example, a central film layer for producing the tensile strength may have a greater thickness than an outer film layer arranged thereon, which supports the strand body protects against the cutting of a thread. The thickness of a film layer is measured at right angles to its plane of extent.

The described heald is produced by providing at least a first film web and a second film web. The two film webs are placed on each other to form the at least one reinforcing portion and connected to each other, for example by gluing or another cohesive connection. Alternatively, the film webs can also be joined together directly in their manufacturing process step, for example by means of coextrusion of the multilayer web. To increase the strength of the multilayer web, it can be stretched in its direction of extent in the course direction of the web and / or transversely thereto in the width direction. The molecular structures are aligned and the strength increased in the direction of stretching. It is also possible to stretch one or more of the film layers and then join them together to form the multilayer web.

In this way, a multilayer web is formed at least in the reinforcing sections. From this at least partially multi-layered web then the strand body is cut out, for example by punching. The heald body is thus designed as a separating part or stamped part. First, the end eyelets and the thread eye can be punched out. At the same time or subsequently, the outer contour of the strand body is then punched out. From a multilayer web can be punched out in this way a variety of Litzenkörpern.

As an alternative to stamping, the stranded body can also be cut out of the ordinary web, for example by laser or ultrasonic cutting.

In a preferred embodiment, the cut or punched strand body is not further processed but represents the finished heald. Alternatively, depending on the stiffness of the strand body, for example, it may be necessary to extend the central longitudinal section around the thread eye out of the plane of extent the punched strand body extends to twist out, since the warp direction is oriented approximately at right angles to the course of the Litzentragschienen. However, with very delicate threads it may be necessary to plastically deform the thread eye region in order to reduce the force exerted by the torsional moment of the heddle on the warp thread , In such healds, the longitudinal section in the area of the thread eye is twisted after the stranded body has been severed and plastically deformed, for example by thermal action, so that it remains in this position.

• Fig. 1 eine stark schematisierte Darstellung einer 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 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 weitere Ausführungsform einer Weblitze in schematischer Ansicht auf die Flachseite in der Erstreckungsebene der Folienlagen und
• Fig. 6 eine Ausführungsform eines Verstärkungsabschnitts der Weblitze im Bereich eines Fadenauges mit mehreren inneren Folienlagen und zwei äußeren Folienlagen.

In the following, the heald and the manufacturing method will be explained with reference to exemplary embodiments. From the description and the dependent claims, there are further advantageous embodiments, wherein the drawing is complementary to use. Show it:

• Fig. 1 a highly schematic representation of a heddle in side view of the end eyelets and the thread eye,
• Fig. 2 a schematic perspective view of a multilayer web, from which the heald body after FIG. 1 can be punched out,
• Fig. 3 a further embodiment of a heddle in a highly schematic side view of the end eyelets, wherein the longitudinal section is twisted in the region of the thread eye,
• Fig. 4 a partially sectioned view of the thread eye transverse to the longitudinal direction of the heald after Fig. 3 according to section line IV-IV,
• Fig. 5 a further embodiment of a heald in a schematic view of the flat side in the plane of extension of the film layers and
• Fig. 6 an embodiment of a reinforcing portion of the heald in the region of a thread eye with a plurality of inner film layers and two outer film layers.

Exemplary embodiments of a heddle 10 with a heddle body 11 extending in a longitudinal direction L are shown in the drawing. The heddle body 11 has a thread eye 12 for guiding a warp thread, which is arranged approximately centrally in the heddle body 11. At the two longitudinal ends, an end eye 13 is provided on the heddle body 11, which serves for arranging the heald on the heddle rails of a heddle shaft. The end eyes 13 are shown in the embodiments described here as a ring-shaped closed O-shaped end eyelets. Alternatively, it is also possible to open the end eyes laterally at one point to form C-shaped or J-shaped end eyelets.

The illustrated in the drawing, various embodiments of the heald 10 are highly schematic and not drawn to scale. In the drawing, only the principle of the heald 10 according to the invention and their preparation will be illustrated.

The heddle body has a multilayer structure at least along a reinforcing section 15 extending in the longitudinal direction L. At least within the reinforcing section 15, the heddle body 11 consists of two or more foil layers 16, which are laid flat on one another and connected to one another. The film layers 16 are in particular materially connected to each other surface, for example glued. The cohesive connection is preferably carried out over the entire surface along the entire contact surface between the adjoining film layers 16. Alternatively, different film layers can already be produced by coextrusion and joined together in one step, so that a subsequent joining process such as gluing can be dispensed with.

The number of foil layers 16 in a reinforcing section 15 can vary. Preferably, there is at least one central or inner film layer 16a sandwiched between two outer film layers 16b. The at least one inner film layer 16a is used in the embodiment to give the strand body 11 the necessary tensile strength. For this purpose, the thickness of the at least one inner film layers 16a, the number of inner film layers 16a, the material, etc. is selected accordingly. Preferably, the entire heddle body 11 is made of plastic. The various film layers and in particular the inner film layers 16a and the outer film layers 16b may consist of different plastics. It is also possible to use composite materials based on plastics, wherein a plastic matrix additional elements are added, which may for example consist of glass and / or ceramic and / or metal. Such additional elements may 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 reinforcing sections 15, the two outer film layers 16b serve to increase the wear resistance of the heddle body 11 with respect to the warp thread 19 and with respect to the heddle support rails. Therefore, in a preferred embodiment, at least three reinforcing sections 15 are provided. In these three reinforcing portions 15 are the two end loops 13 and the thread eye 12. Especially in the central reinforcing portion 15 of the heddle body 11 must be protected against being cut by the warp thread 19. In use position, the heald 10 is greatly accelerated and takes the guided in the thread eye 12 warp thread to this in the desired To give an opinion. Because of the large accelerations also relatively large forces between the warp thread 19 and the heald body 11 act. For this reason, the two outer film layers 16b are made around the thread eye 12 around of a plastic or composite material, which is particularly resistant to wear and a long service life of the heald 10 guaranteed. For example, polyethylene, polypropylene or polycarbonate can be used for the at least one inner film layer 16a. For the outer film layers 16b, for example, polyamide can be used. The plastics mentioned can also be used as a plastic matrix in a composite material. For the production of the heddle body 11 film webs are provided, which are connected to each other flat and then form a multilayer web 17, as exemplified in Fig. 2 is shown. In this embodiment, the entire heddle body 11 is designed in several layers in its longitudinal direction L. The number of film layers 16 is constant in the longitudinal direction L along the strand body. All foil layers 16 extend over the entire length of the heddle body 11.

From such a multi-layer film web 17, the heald body 11 is subsequently separated out. Preferably, the heddle body 11 is punched out. The stamping process can be done in one or more steps. It is possible initially to punch out the thread eye 12 and the end eyes 13 from the film web 17 in a first punching operation. Then then the outer contour 18 can be punched out. Alternatively, the punching operations can also take place simultaneously. After punching gives a heald body 11 as a stamped part as he schematically in Fig. 1 is shown.

Depending on the torsional rigidity of the heddle body 11, it may be necessary to adjust the plane in which the thread eye 12 extends, with respect to the plane in which the end loops 13 extend to twist, as shown by the FIGS. 3 and 4 is illustrated. For this purpose, a central longitudinal section of the heddle body 11 can be plastically deformed in order to fix the thread eye plane with respect to the plane of the end loops 13 in the twisted position. This makes it possible to guide a warp thread 19 through the thread eye 12 without the warp thread 19 is acted upon by a torsional moment of the heald 10.

The film layers 16 of the heddle body 11 may be shorter in the longitudinal direction L than the heddle body 11 and may be arranged only in a reinforcing section 15. In the transverse direction Q transversely to the longitudinal direction L and in the plane of extent of the film layer 16, all film layers 16 extend over the entire width of the strand body 11.

In modification to the in the FIGS. 1 to 4 illustrated embodiments is in the embodiment of the heald 10 after Fig. 5 the heald body 11 is made non-uniformly thick in the longitudinal direction L. It has a plurality of and, according to the example, three reinforcing sections 15 spaced apart in the longitudinal direction L. These are located in the two end regions at the end loops 13 and in the middle region at the thread eye 12. The two end reinforcing sections 15 are connected to the central reinforcing section 15 via a respective connecting section 21. The number of film layers 16 is less in the connecting portions 21 than in the reinforcing portions 15. In the embodiment, the connecting portions are formed by only one central or inner film layer 16a. This inner film layer 16a extends through the entire strand body 11 in the longitudinal direction L. In the reinforcing sections the inner foil layer 16a is reinforced by at least one further foil layer and, according to the example, is sandwiched by two outer foil layers 16b arranged on opposite sides in each case. To produce such a heald 10, the multilayer web 17 has only at the corresponding after the separation of the heddle body 11 the reinforcing sections 15 points over several layers of film. The view on the leading edge of such a film web 17 would be as shown in FIG Fig. 5 correspond.

The individual film layers 16 may be made different thickness depending on their function and / or depending on the material used. A merely exemplary representation of different thicknesses of film layers 16 is shown in FIG Fig. 6 outlined. In this embodiment, a plurality of inner film layers 16a are provided, each having a thickness there. All the inner film layers 16a extend in the longitudinal direction L along the entire strand body 11. The total thickness di therefore results from the thickness da of an inner film layer 16a multiplied by the number of intended inner film layers 16a. By way of 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 allows a very flexible and cost-effective production of healds 10, the production can be 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 to this could on both sides of the heddle body 11 respectively also a plurality of outer film layers 16b may be provided.

The invention relates to a heald 10, the heald body 11 is at least partially constructed in several layers. The heddle body 11 has at least one reinforcing section 15, which consists of several foil layers 16. Preferably, at least one inner foil layer 16a extends in the longitudinal direction L along the entire heddle body 11. This at least one inner foil layer 16a is in particular in the section around the thread eye 12 and / or in the section around the end loops 13 of the heddle body 11 with at least one and preferably two outer Foil layers 16b reinforced to form reinforcing portions 15. The reinforcing sections 15 can, so to speak, be sandwiched from preferably at least three foil layers 16a, 16b. This results in a simple production by providing an at least partially multi-layered film web and cutting or punching of the strand body 11 from this multilayer film web.

LIST OF REFERENCE NUMBERS

10

heald

11

heald

12

thread eye

13

end loop

15

amplifying section

16

film layer

16a

inner foil layer

16b

outer foil layer

17

sheet

18

outer contour

19

warp

21

connecting portion

there

Thickness of the inner film layer

db

Thickness of the outer film layer

di

Total thickness of all inner foil layers

L

longitudinal direction

Q

transversely

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 warp thread,
   wherein the heald body (11) at least in a reinforcing portion (15) has at least two film layers (16a, 16b) which lie flat against each other and are connected together, characterised in that a connecting portion (21) of the heald body (11) connects to the at least one reinforcing portion (15) of the heald body (11) with at least two film layers (16a, 16b), wherein the connecting portion (21) has fewer film layers (16a) than the adjacent 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 a plurality of 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 in the longitudinal direction along the entire heald body (11).
7. Heald according to claim 6, characterised in that in the reinforcing portions (15), the central film layer (16a) is arranged between two outer film layers (16b).
8. Heald according to claim 1, characterised in that one film layer (16a) is produced from a first material and at least one other film layer (16b) is produced from a second material.
9. Heald according to claim 1, characterised in that the heald body (11) is made from a plastic material or a 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) on its flat sides at least in portions, and/or in the region of the thread eye (12) on its outer face, is provided with a metal coating.
12. Heald according to claim 1, characterised in that the thickness (da, db) of two film layers (16a, 16b) in one reinforcing portion (15) is different.
13. Heald according to claim 1, characterised in that the longitudinal portion in the region of the thread eye (12) is twisted relative to the extension plane of the remaining heald body (11).
14. Heald according to claim 1, characterised in that a reinforcing portion (15) is provided, within which the thread eye (12) is situated.
15. Heald according to claim 1, characterised in that two reinforcing portions (15) are provided, within which the end eyelets (13) are situated.

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