The present invention relates to a metal rope, which comprises wires with a surface of stainless steel, e. g. stainless steel wires. The present invention also relates to a fabric comprising a colored metal rope and to the use of such a metal rope in architectural and decorative applications.

Background of the invention.

Such metal ropes are known in the art.

Metal ropes with stainless steel wires are frequently used where resistance against corrosion is of utmost importance. The original stainless wires often have a bright outlook, which gives to the construction where the rope is used an esthetical aspect. As time lapses, however, the rope looses its bright aspect. The outlook of the rope becomes dull.

There are tendencies in the art to replace stainless steel wires by plain carbon steel wires with an enhanced corrosion protection layer. An example is a plain carbon steel wire provided with a zinc coating and on top of that a polymer coating. Coloring pigment may be added to the polymer in order to give the wire an esthetical aspect.

Summary of the invention.

It is an object of the invention to avoid the drawbacks of the prior art.

It is a further object of the invention to maintain the bright and esthetical aspect of ropes with stainless steel wires.

According to a first aspect of the present invention there is provided a metal rope with wires having a surface of stainless steel. At least those wires exposed to the surface of the rope are coated with a transparent polymer, which is selected from the group consisting of thermoplastic polyesters, polyimides, polyamides and polyphtalamides, or a copolymer

thereof.

A wire with a surface of stainless steel can be a common stainless steel wire or can be a wire with a metal core, e. g. a core of plain carbon steel, and with an external layer of cladded stainless steel.

Preferably a thermoplastic polyester is used as polymer. Thermoplastic polyester has the advantage of giving a good adhesion with the stainless steel wire and of having a low degree of moisture absorption.

The good adhesion level is obtained without pickling treatment on the stainless steel wire so that the initial bright aspect of the stainless steel wire is not reduced. The low degree of absorption further guarantees that this bright aspect is kept for a long time.

This thermoplastic polyester is selected from the group consisting of. polyethylene terephtalate, polybutylene terephtalate, polyethylene naphtenate or any copolymer comprising polyethylene terephtalate, polybutylene terephtalate or polyethylene naphtenate.

According to a preferable embodiment of the invention, the transparent polymer comprises a transparent organic coloring agent, which can be added to the polymer in the form of small grains in a carrier of a similar or same polymer. This embodiment offers the advantage of various colors depending upon the concentration and type of coloring agent : metallic like colors and fluorescent colors may be applied to the stainless steel wire in this way. The coloring agent together with the transparency of the polymer and the bright aspect of the stainless steel wires give to the rope a typical metallic look.

The individual thermoplastic polyester coating on some of the wires is not damaged seriously during the twisting operation. Indeed thermoplastic polyester exhibits a good resistance against abrasion.

Furthermore, thermoplastic polyester has a relatively low coefficient of friction.

According to a second aspect of the present invention, a fabric is provided comprising a metal rope according to the first aspect of the invention. This fabric may be a woven structure or a knitted structure.

In case of a woven structure, the colored metal rope may form the warp, or the weft or both.

A metal rope according to the invention can be used in the structural field, i. e. in the building and architectural field, and in the decorative field.

Within the building and architectural field several applications are possible.

A first application is the use of the metal rope as stay rope or stay strand for suspension bridges with a high span length of support. Here the individual steel wires of the metal rope often have diameters exceeding 4.0 mm. Metal ropes for this application often comprise more than one strand of twisted wires.

A second application is the use of the metal rope as stay rope or stay strand for roof support or for outside wall support. Roofs for sport stadium, sport halls, airport buildings, exposition halls can be suspended on such metal ropes. The possible application of various colors is also more important in this second application than in the first application.

A third application is the use of the metal rope for stays and supports of antennas and masts.

Within the decorative field various applications are also possible.

The metal wire rope according to the invention can be applied for the suspension of lighting apparatus, for the building of stands at expositions and exhibitions, for the interior and exterior design of shops, suspension or lifting of objects in theaters. In the decorative field, the wire diameter is usually much smaller than the wire diameter of ropes used in the architectural field.

The second aspect of the present invention, the fabric comprising the colored wire rope, may also have various building and decorative applications. The fabric may be used as a balustrade for terraces, stairs and bridges. The fabric may function as a ceiling in public buildings. The fabric may also be used as a decorative woven structure for inner or outer walls. The fabric can even be used in furniture.

Brief description of the drawings.

The invention will now be described into more detail with reference to the accompanying drawings wherein -FIGURE 1 shows a cross-section of a multi-strand metal wire rope according to the invention; --FIGURE 2 shows a cross-section of a first embodiment of a wire of the metal wire rope according to the invention; - FIGURE 3 shows a cross-section of a second embodiment of a wire of the metal wire rope according to the invention; - FIGURE 4 shows a cross-section of a single-strand metal wire rope according to the invention; - FIGURE 5 illustrates a longitudinal view of an end of a wire rope according to the invention; - FIGURE 6 illustrates an application of a wire rope according to the invention in the decorative field ; - FIGUREs 7,8 and 9 are top views of woven structures according to the second aspect of the present invention; - FIGUREs 10,11 a and 11b and 12 are cross-sectional views of woven structures according to the second aspect of the present invention; -FIGURE 13 is a top view of a knitted structure according to the second aspect of the present invention.

Description of the preferred embodiments of the invention.

FIGURE 1 shows a cross-section of a metal rope 10 according to the first aspect of the present invention. The metal rope 10 is a multi-strand rope, i. e. metal rope 10 comprises more than one strand. A core strand 12 is surrounded by six layer strands 14. The core strand 12 comprises seven stainless steel wires 16. Each layer strand 14 comprises seven stainless steel wires. The six wires 18 are each individually exposed to the surface of the wire rope 10 due to the twisting of the strand 14.

These six wires 18 are provided with a transparent polyester coating where a transparent organic coloring agent has been added.

FIGURE 2 shows a cross-section of a first embodiment of a wire 18 with a full stainless steel core 20. The stainless steel core 20 is provided with a polyester coating 22.

FIGURE 3 shows a cross-section of a second embodiment of a wire 18.

This wire may have a core of plain carbon steel 24. The core 24 is cladded with a stainless steel 26. The cladded wire is then provided with a polyester coating 22.

Wire rope 10 of FIGURE 1 has a 7x7 construction.

Other embodiments and constructions are possible.

Examples are single-strand wire ropes : 1+6 or 7x1 1+6+12 or 19x1 Other examples are multi-strand constructions : 7x7<BR> 7x19.

The diameter of the rope may range between broad limits such as from 0.50 mm to 180.0 mm, e. g. from 0.50 mm to 60.0 mm, and depends largely upon the application, the greater diameters being used in the architectural and building field.

FIGURE 4 shows a cross-section of a single-strand construction of a metal wire rope 10 according to the invention. Such a construction is also often called a spiral strand. It consists of up to eleven layers of stainless steel wires. The wires 16, which are not exposed to the surface, are left blank. The wires 18, which are exposed to the surface, are provided with a transparent polyester coating where a transparent organic coloring agent has been added.

The diameter of the individual wires may vary between 0.30 mm and 8.0 mm, e. g. between 0.40 mm and 5.0 mm.

The thickness of the polyester coating on the final steel wire 18 may range from 20 micrometer (urn) to 150 um. The minimum values are imposed by reason of providing a sufficient abrasion resistance. The ; maximum values are imposed by reasons of cost and by reasons of maintaining a sufficient level of transparency.

Typical stainless steel compositions for the stainless steel are according to norms AISI 302, AISI 304 and AISI 316.

The polyester coating is preferably applied to the individual wires by means of an extrusion process.

FIGURE 5 illustrates an end of a metal wire rope 10 according to the invention. The end of the metal wire rope is clamped into an end piece 30 in the form of a fork to enable to attach the wire rope 10 to a construction, roof,. wall etc...

FIGURE 6 illustrates an application of a metal wire rope 10 within the decorative field. The metal wire rope 10 forms the essential part of a stand 31. Tension sleeves 32 tension and fix the wire rope 10 to the base floor. The wire rope is guided over a guiding wheel 34 fixed to a wall. Distant keepers 36 take care that an appropriate distance is kept

between two parts of the wire rope 10. A rack bottom plate 38 rests on supports 40, which are attached to the metal wire rope 10.

FIGUREs 7 to 13 all illustrate woven structures 144 according to the second aspect of the present invention.

In FIGURE 7 steel cords 10 form the warp whereas synthetic yarns 146 such as aramide form the weft. Individual steel filaments 18 are provided with a transparent polyester coating where a transparent organic coloring agent has been added. A nylon filament 148, such as nylon 940/2/2 binds the warp to the weft.

In FIGURE 8 steel cords 10 form the weft whereas synthetic yarns 146 form the warp.

In FIGURE 9 steel cords 10 both form the weft and the warp. A nylon filament 148 holds both weft and warp together. In FIGURE 9 both the weft and the warp are straight steel cords 10. An alternative embodiment, however, may be provided by having the weft cord 10 alternatingly go up and under the warp cord 10.

In the woven structure 144 of FIGURE 10 steel cords 10 form the weft and nylon filaments 148 form the warp in an alternating zigzag way: a first nylon filament 148 goes over and under and over the steel cords 10, a second nylon filament 148 goes under and over and under the steel cords 10, etc...

In the woven structure 144 of FIGURE 11 a and 11 b steel cords 10 form also the weft and nylon filaments 148 also form the warp in an alternating zigzag way, but here the nylon filament 148 goes over two steel cords 10, and subsequently under two steel cords 10 etc... in other words, the pitch of the warp nylon filaments is four steel cords instead of two.

FIGURE 12 shows the cross-section of a so-called solid woven structure 144 which exists as such for reinforcement of conveyor belts. Such a solid woven structure has two layers of steel cord 10 as warp, and three layers of synthetic filaments 146 or steel cords as weft. The warp and weft layers are bound by means of nylon filaments 148.

FIGURE 13 shows a knitted structure 150 as farbic where various steel cords 10 have been knitted together.