The subject of this invention is a heddle, preferably for the processing of tape-shaped material, and a method for the manufacture thereof.
Heddles and methods for manufacturing them are known. Traditionally, they serve primarily for weaving yarns and wires. Particularly in more recent times, heddles have also been used for weaving tapes. The subject of the EP 1 795 636 B1, for example, is a heddle for tape-shaped warp yarn. The heddle shown there is optimized primarily for the production of industrial fabrics of the kind used, for example, in the manufacture of fibre composites.
The EP 1 795 636 B1 shows a heddle consisting substantially of two bands which are parallel to each other and spaced apart from each other.
Spacers and two rod-like components that form the thread eye are located in the gap between the bands. The spacers, but not the rod-like components forming the thread eye, are provided in part with fastening elements, each of which engages a recess in one of the bands. End loops are provided at both ends of the bands, and the heddle shown in the EP 1 795 636 B1 accordingly has four end loops. The aforementioned publication contains no detailed information concerning the manufacture of the heddles illustrated.
The heddle shown in the EP 1 795 636 B1 is optimized primarily for the production of industrial fabrics of the kind used, for example, in the manufacture of fibre composites. The price of the heddles used in the processing of expensive materials such as CRP yarn is of rather secondary importance.
However, particularly in industrial fields in which manufacturers are under greater pricing pressure than are manufacturers of fibre-composite components, further uses of heddles for the processing of tapes might arise. The manufacture of packaging from tape-like plastic materials, from which woven fabrics are formed, is one such field. For the manufacture of packaging materials of such kind—e.g. sacks—use is made primarily of circular looms.
The object of the present invention is therefore to propose a heddle that can be produced economically and that is of narrow width, thereby enabling it to be used in difficult installation positions—as in the case of circular weaving.
Joins in the sections in which the two bands make mutual contact, preferably with their flat sides, can also be made economically. Substance-to-substance joining techniques, such as adhesive bonding, welding or soldering, can be used here to advantage. It is also conceivable that other techniques, such as riveting or the use of clips, which result, for example, in a form fit, also offer advantages. Joins at which, for example, the bands penetrate each other or cross over and lock mechanically are also conceivable. The precise shape of the joins is not limited to given shapes, e.g. a round shape, in any of the joining methods cited, but may be completely arbitrary so as to suit the requirements.
Surprisingly, it proved to be advantageous if the distances between the thread eye and the closest joins above and below it are small. The smaller these distances are, for example, the greater is the stability of the heddle. To advantage, for instance, are distances which are less than half, a third, a quarter, a sixth, an eighth or even a tenth of the distance between the thread eye and the end loop on the side in question. It is advantageous if the distance between the thread eye and the end loop is at least 1.5 times the distance between the thread eye and the join.
Additional benefits arise in this context for the following reason: the two bands, which are spaced apart in the area in which the thread eye is incorporated in the heddle, generally exert a force (a force perpendicular to the plane spanned by the longitudinal direction of the heddle and the widthwise direction of the two bands), which opposes the spacing between the two bands and with which the thread eye, or the at least one component limiting the thread eye, can be clamped between the two bands. The smaller the distance between the thread eye and each of the two joins closest thereto, the greater is this clamping force. However, in order to preserve the warp material, it is advantageous if the distance between the thread eye and the closest join is greater than the width of the thread eye. This configuration is gentle particularly on the adjacent warp tapes sliding past the heddle laterally.
In addition, or alternatively, a perpendicular force of this kind may be generated if, in the fitted position, at least one of the bands (or both bands) is/are in a stressed state. This is the case if, for example, in the portion between the two joins closest to the thread eye, the band in question is fully deflected or even lengthened. Hooke's Law, among others, then applies.
The at least one component interlocks by way of a fastening element with at least one of the bands. Often, each such component interlocks by way of a fastening element with each of the two bands. In a useful refinement of the invention, at least one component has fastening elements that engage both the bands. A component of this kind may also have a plurality of fastening elements that engage a band. Engagement of a fastening element with a band may be effected by providing the band with a recess that completely perforates the band. Alternatively, the recess may only partially penetrate the band or even be configured such that “recesses” in the band are created by inwardly projecting material deformations, e.g. without removing any band material. In this or other ways (here, for example, by stamping), fastening elements may also be created on the band, or on both bands, which engage at least one component.
The component is made preferably of a ceramic material but may also be produced, e.g. as a sinterered, MIM or injection-moulded part.
It is to advantage if a fastening element has a surface that makes contact with at least one of the two bands and serves as a stop, thereby halting the relative movement—here an approach—between the band and the fastening element at the point of contact.
Where there is a plurality of fastening elements, the contact surface may be located between the fastening elements. It may then be to advantage to provide a relief groove between the contact surface and the surfaces of each of the fastening elements so as to ensure that the surfaces are executed with the greatest possible precision.
It is also possible to have a plurality of contact surfaces, particularly if a plurality of fastening elements is provided, which may be interconnected, e.g., across the relief grooves.
Rising surfaces may be present, which may serve to ensure that the components forming the thread eye are positioned correctly relative to the bands, and are kept in position, by the perpendicular force exerted by the bands. To this end, the rising surfaces are configured such that the angle between them and the contact surface is not a right angle. This angle may be obtuse or acute. The contact surface may also be only approximately planar or at least feature an angle other than 90° relative to the component's centre line. The contact surface may be adapted shapewise to the deflection curve of the band with which it makes contact. A shapewise adaptation to the deflection of the bands may be advantageous for all the end-face surfaces.
It has proved advantageous if the thread eye is defined by at least two components which limit the thread eye. The components will often have the shape of a bridging member. It is to advantage if at least those parts of the components that come into contact with the yarn or tape-like warp material are rounded.
For a wide variety of reasons, it has proved advantageous if the end-loop portion of the heddle remains free of joins, thereby facilitating suspension of the heddles, which are usually flexible. It is also to advantage if, at least in one end-loop portion but preferably in both end-loop portions, only one heddle band is provided. In cases where there are two bands in at least one end-loop portion, it is possible to configure the end loops of the two bands differently. They may, for example, be shaped superposably and oriented as mirror images, i.e. rotated by 180° relative to one another about the band's longitudinal axis. A further alternative is to shape the end loops of the two bands differently.
The following procedural features are advantageous for manufacturing the heddles described in this publication:
It is normally advantageous to make notches and recesses in the bands before these are brought together and/or connected. However, these may also be made after the bands have already been brought together or even already connected, particularly if the bands are configured such that they are superposable and/or if they have recesses in the same places. In this case, the creation of recesses by “punching through” is particularly recommendable. Where applicable, even the punching through of more than two bands would appear expedient.
Creation of a space between the two bands in a portion—between the at least two joins—of their extension in the heddle's longitudinal direction may be undertaken after the bands have been brought together and even after formation—for example by spot welding—of the joins. To this end, a wedge may be introduced into the portion of the two bands where they are to be spaced apart. It is to advantage in this context if, in the portion concerned, the two bands are not superposed with zero clearance. A gap between the two bands may be ensured by introducing, before the bands are brought together, a removable spacer into the portion where they are to be spaced apart. The spacer may be removable but may also remain in the spaced-apart portion as a permanent component of the heddle. In this case, the spacer may serve as a component that limits the thread eye.
However, raised impressions in one or both bands may also serve as spacers, provided they are raised relative to the rest of the band's surface and the raised area faces towards the other band. In the aforesaid cases, the spacing tool—a wedge, as a rule, as mentioned—may be inserted into the gap to widen it.
It is also conceivable, however, to configure the diameter of the “gap” such that it need not be widened further by the wedge. In this case, accordingly, the spacer determines the distance by which the two bands will later be spaced apart in the end-loop portion. According to this version of the “procedural features” outlined above, this space is formed as the bands are brought together and not thereafter, meaning that the procedural features for the last-mentioned embodiment do not necessarily follow each other in succession like procedural steps. However, if one first brings the two bands together and then creates a space between them, or, if necessary, widens an existing gap (see the above, first-mentioned embodiment of the production process) the above procedural features follow each other in succession like procedural steps.
In both cases, the result is a portion in which the two bands are spaced apart and into which the thread eye is introduced in some manner. This portion with a gap between the bands extends between the at least two joins.
Further embodiments of the present invention follow from the dependent claims and the description. The description, too, is limited to essential features of the invention, with the individual features generally being applicable to advantage in all the embodiments.
The drawings supplement the description.
The technical features of the individual embodiments can generally be used to advantage in connection with all the embodiments of the invention.
A number of selected embodiments of the invention are described below by reference to the drawings.
Two components 6, 7, which limit the thread eye 8, are held between the two bands 2 and 3. In the embodiment shown, the two components 6, 7 have fastening elements 9, 10 which engage recesses 11, 12 in the two bands 2, 3. In the embodiment shown, the recesses 11, 12 are holes which perforate the bands. However, blind holes created, for example, by stamping or notching are also conceivable.
The fastening-element configuration shown in the aforementioned three drawings is particularly advantageous. It is to be noted in this context that the surfaces of the end face are not parallel to the centre line 27, shown in
Number | Date | Country | Kind |
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12191836.1 | Nov 2012 | EP | regional |
13003701.3 | Jul 2013 | EP | regional |
This patent application is the national phase of PCT/EP2013/003316 filed Nov. 5, 2013, which claims the benefit of European Patent Application No. 12191836.1 filed Nov. 8, 2012 and European Patent Application No. 13003701.3 filed Jul. 23, 2013.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/003316 | 11/5/2013 | WO | 00 |