WO1999051806A1

WO1999051806A1 - Cloth structure

Info

Publication number: WO1999051806A1
Application number: PCT/NL1999/000205
Authority: WO
Inventors: Matthijs Arnold Stam
Original assignee: Bw Industrial Products B.V.
Priority date: 1998-04-07
Filing date: 1999-04-07
Publication date: 1999-10-14
Also published as: NL1008837C2; AU3174599A

Abstract

The invention relates to a cloth (1), for instance for covering a pane, which cloth consists of a fabric comprising warp threads (2) placed mutually parallel and weft threads (3) placed perpendicularly thereof, wherein the weft threads run alternately below and above the warp threads. The cloth has the feature that the mutual distance between first mutually parallel threads varies such that the fabric has zones (II, III) of differing densities.

Description

CLOTH STRUCTURE

The invention relates to a cloth, for instance for covering a pane, which cloth consists of a fabric comprising warp threads placed mutually parallel and weft threads placed perpendicularly thereof, wherein the weft threads run alternately below and above the warp threads.

It is known to cover a pane with curtains which can be opened or closed as desired. When direct looking-in is not desired, a second cloth can be used to cover the pane, this cloth normally being designated a net curtain. Due to the open structure of the net curtain it is herein possible to look outside without it being easily possible to look in from outside. A drawback is that two different cloths are arranged over the pane. It is also known to use slats as window covering.

The slats can herein have a variable adjustment, whereby the degree of opening of the slats can be varied. A drawback of such slats is that the slats obstruct part of the view. It is also possible to look directly inside from the outside.

It is an object of the present invention to obviate the above stated drawbacks.

This objective is achieved according to the invention in that the mutual distance between first mutually parallel threads varies such that the fabric has zones of differing densities.

A pane covering is hereby provided which for instance comprises both an opaque part and a part through which it is possible to look outside but, in the case of light incident from outside, it is not possible to look inside from the outside. By arranging the cloth so that it can for instance be rolled up such that the 2 cloth can be displaced relative to the pane, the pane covering can be placed in an open or closed position.

The cloth according to the invention can likewise be used in a climate control, wherein the transparency of the cloth, or the sun-screening, can be adjusted depending on the solar radiation. According to a particular embodiment of the invention the cloth herein has a density which changes evenly.

In another embodiment the weft and warp threads are of plastic. The threads can hereby be fixed relative to each other in simple manner, for instance by heating, whereby the structure of the cloth is better preserved. It is also possible to fix the threads relative to each other by means of a coating. In very advantageous manner the cloth according to the invention can be applied in a climate gable, wherein air is drawn in through the cloth and extracted via a cavity. The cloth can herein vary in density, whereby the regulation of the climate control adjusts the cloth subject to the required cooling such that the air is drawn in via a zone with the desired density.

Already mentioned as application of the cloth according to the invention is the possibility of light control. This can be used for instance for sun- screenings, for instance for simple climate control in houses, offices, greenhouses, as well as in illuminated advertising and tents. It is further possible to envisage a variable gas permeability, for instance air permeability, for air-conditioning systems. The cloth according to the invention can also be used for filters. Attention is drawn to the fact that a cloth according to the invention, wherein the density changes in stepwise manner, which cloth therefore has discrete zones with differing densities, can be manufactured by varying the centre distance of like threads as well as by embodying the cloth such that threads in the different zones have different dimensions in the main 3 plane of the cloth, for instance while retaining their mutual centre-to-centre distance.

It should further be understood that the threads can have different cross-sections, for instance a round shape, but also an elongate, more or less rectangular shape. In this latter case the threads are more or less ribbon-shaped.

In the case for instance the centre distance is maintained and different threads are used for the different zones, there is a change of yarn type during the weaving process.

All known types of yarn can in principle be considered suitable, for instance spun yarns, filament yarns, monofilament yarns, elastic yarns, metal yarns, ribbon yarns and the like. The threads according to the invention can even be defined as strips, tubes and rods.

In a specific embodiment the cloth according to the invention is metallized. Specific light effects can be realized herewith and the cloth is not subject to static charging.

According to another aspect of the invention the cloth according to the invention has the feature that the second threads extending perpendicularly of said first threads at varying mutual distances are elastic such that their said mutual distances can be adjusted by adjusting the tensile force in the second threads.

An alternative has the special feature that the second threads extending perpendicularly of said first threads at varying mutual distances are electrostrictive such that their said mutual distances can be adjusted by adjusting the voltage over the second threads.

These and other features of the invention will be further elucidated in the annexed drawings.

Figure 1 shows schematically a cloth according to the invention.

Figure 2 shows an enlarged part of a first zone of the cloth. 4

Figure 3 shows an enlarged part of a first embodiment of a second zone of the cloth.

Figure 4 shows an enlarged part of a second embodiment of a second zone of the cloth. Figure 5 shows schematically an enlarged part of another cloth according to the invention.

Figure 6 shows a partly broken-away perspective view of a generally tubular cartridge filter with a cloth according to the invention. Figure 7 shows a partly broken-away side view of a filter unit with a number of filters as according to figure 6.

Figure 8 shows schematically a cross-section through a filter with a cloth according to the invention.

Figure 9 shows a cross-section corresponding with figure 8 through an alternative.

Figure 1 shows a cloth 1 comprising a first zone II and a second zone III. Figure 2 shows an enlargement of the first zone II of cloth 1. It can be seen here that the cloth consists of warp threads 2 running parallel and weft threads 3 lying perpendicular thereto. The distance A between two adjacent warp threads is roughly equal to the distance B between two adjacent weft threads. The thickness of the threads and the distances A and B determine the density of the first zone.

Figure 3 shows a first embodiment of the second zone of cloth 1. Warp threads 2 and weft threads 3 can likewise be seen herein. In this first embodiment the distance A' between two adjacent warp threads is smaller than the distance B¹ between two adjacent weft threads. Particularly assuming that the distance A' equals the distance A of figure 2, a density of the cloth is hereby obtained differing from the density of the cloth in the first zone. 5

Figure 4 shows a second embodiment of the second zone of cloth 1. This second embodiment corresponds for the most part with the first embodiment of figure 3. The distance A" between two adjacent warp threads is however greater here than the distance B" between two adjacent weft threads. Another density of the cloth is likewise hereby obtained.

It is thus possible to vary the density of the cloth either by varying the distance between the warp threads or by varying the distance between the weft threads, or by varying both distances.

Cloth 1 can for instance be woven on a loom. In order to retain the structure of the fabric, the threads can be fixed relative to each other by a coating. It is also possible to embody the threads in plastic and to fix them relative to each other by heating, for instance by means of calendering.

A cloth according to the invention can be embodied with a stepwise varying density or an evenly progressing density. Such a cloth can herein be arranged on rollers in front of a pane, whereby the cloth is displaceable relative to the pane and the sun-screening or the option of looking through the pane can be varied.

Figure 5 shows very schematically an enlarged portion of a cloth 11 according to the invention.

Other than cloth 1 as according to figure 1, cloth 11 of figure 5 has no discrete zones with different densities but cloth 11 has a density changing in vertical direction, as expressed in the number of threads 12 per vertical unit of length. The mutual distance between the threads 13 extending in vertical direction is the same over the whole cloth 11.

Owing to the structure of cloth 11 the mutual distance between threads 12 depends on the position (in vertical direction in figure 5) . At the top the permeability of the cloth to light, liquid, gas is thus smaller than at the bottom of cloth 11. 6

In this embodiment the threads 12 are everywhere the same. The described variation in density is realized by continuously adjusting the mutual distance between threads 12 during the weaving process. The embodiment according to figure 1 is based on this same principle, be it in discontinuous or discrete form. All threads extending in horizontal direction are the same. In zone II however, the thread density in this random embodiment is roughly twice as great as in zone III.

This same effect could alternatively be achieved by maintaining the same mutual centre-to-centre distance between the threads but choosing threads for zone II of a type differing from those in zone III. It will be apparent that the decisive quantity here is the relevant transverse dimensioning of the threads in question. The width of these yarns can be easily chosen, particularly in the case of ribbon-shaped yarns. During the weaving process a different type of yarn must be chosen at the transition between zones II and III.

Figure 6 shows a filter 13 comprising a perforated housing 14 with an inlet 15. Perforations 16 serve as outlets, this as indicated with arrows 17 and 18 respectively. Via inlet 15 a medium is carried as according to arrows 19 via a perforated cylinder 20 through a filter consisting of at least one layer of cloth according to the invention. As shown in the drawing, cloth 21 is manufactured in a general tube shape, the jacket of which has a surface-enlarging zigzag structure.

In order to make the pressure drop over the length of filter 13 substantially the same and to obtain a uniform outflow as according to arrows 18, use can advantageously be made of a structure of the cloth as shown schematically with cloth 11 in figure 5. At the top the cloth must cause a relatively great flow 7 resistance, while at the bottom the flow resistance must be smaller.

It will be apparent that the degree to which the flow through the cloth varies over the height of the filter depends on the design of the filter and the medium to be passed through.

Filter 13 is for instance suitable as dust filter in air conditioning installations or the like.

Figure 7 shows a filter unit 31 in which use is made of a number of tube filters or candle filters 13 as according to figure 6. Unit 31 comprises a cup-like container 32 which can be closed in medium-tight manner with a cover 34 via a flange construction 33. Cover 33 has an inlet 35; the cup-like container has an outlet 36.

Inlet 35 connects onto a space 37 which is bounded by a separating plate 38 clamped in flanges 33 and the cover 34. Infeeds 15 connect onto this space 37.

Figures 8 and 9 show very schematically other filter embodiments, wherein a substantially constant pressure drop and regular outflow over the whole height of a filter can be achieved. Use is made in filter 41 of figure 8 of an internal cylinder shape 42 and an external narrowing cone 43, while in filter 44 of figure 9 use is made of an internal widening cone 45 and an external cylinder 46.

*****

Claims

1. Cloth for covering a pane, which cloth consists of a fabric comprising warp threads placed mutually parallel and weft threads placed perpendicularly thereof, wherein the weft threads run alternately below and above the warp threads, characterized in that the mutual distance between first mutually parallel threads varies such that the fabric has zones of differing densities.

2. Cloth as claimed in claim 1, characterized in that the density changes in stepwise manner.

3. Cloth as claimed in claim 2, characterized in that in the different zones first threads have different dimensions in the main plane of the cloth.

4. Cloth as claimed in claim 1, characterized in that the density changes evenly.

5. Cloth as claimed in claim 1, characterized in that the threads are of plastic.

6. Cloth as claimed in claim 5, characterized in that the threads are fixed relative to each other by heating, for instance by means of calendering.

7. Cloth as claimed in claim 1, characterized in that the threads are fixed relative to each other by a coating.

8. Cloth as claimed in claim 1, characterized in that the cloth is metallized.

9. Cloth as claimed in claim 1, characterized in that the second threads extending perpendicularly of said first threads at varying mutual distances are elastic such that their said mutual distances can be adjusted by adjusting the tensile force in the second threads. 9

10. Cloth as claimed in claim 1, characterized in that the second threads extending perpendicularly of said first threads at varying mutual distances are electrostrictive such that their said mutual distances can be adjusted by adjusting the electrical voltage over the second threads.