The invention relates to apparatus and methods to produce a cutting wire for industrial purposes.

Background

Wires coated with super-abrasives like diamond or Cubic Boron Nitride(CBN) are important tools in the area of cutting, slicing and/or shaping of hard and brittle materials, such as ceramics, glass, minerals, silicon and sapphire wafers, etc.. These abrasive wires are useful cutting tools because they minimize surface damage and kerf loss.

However, when used for different applications the wire strand used as the "substrate" upon which the abrasive materials are placed may not be strong enough to cut different materials.

For instance, the automotive industry, aerospace and precision metal industries also require high precision sawing but involve materials substantially stronger, making conventional abrasion coated wire unsuitable. Summary of Invention

In a first aspect, the invention provides a method for producing a coated wire rope, the method comprising the steps of: guiding an element to a first wire coating device; applying a metal and metal coated grit to said element; guiding said element to a second wire coating device; and applying a metal coating over said metal and metal coated grit; where the element is a wire, twisting a plurality of elements to form a wire rope, or; where the element is a wire rope, twisting a plurality of wires to form said element.

Thus by providing steps to form a wire rope, a wide range of design options become available for the operator to select a wire rope suitable for the cutting of a wide variety of material. Brief Description of Drawings

It will be convenient to further describe the present invention with respect to the accompanying drawings that illustrate possible arrangements of the invention. Other arrangements of the invention are possible and consequently, the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the invention.

Figure 1 is a schematic view of a diamond wire manufacturing process and/or system according to an embodiment of the present invention. Figures 2A to 2C are various views of a cutting wire according to various embodiments of the present invention.

Detailed Description

Figure 1 shows a schematic view of a diamond wire manufacturing process 5 according to one embodiment of the present invention. The process is a reel to reel process beginning from a first reel 10 and ending with an end reel 70. In another embodiment, the first reel may be multiple reels feeding a plurality of wires through the coating process. The wire(s) 20 spanning from the first reel(s) 10 are operated under tension through a plurality of tensioning pulleys 25 with tension provide by a tensioning unit 15. As mentioned, the first reel 10 may in fact be a plurality of reels feeding in a plurality of wires strands through the process 5 in parallel. In one particular embodiment, while the strands are in the tensioning unit 15, a further twisting unit 17 may twist the wires so that a wire rope 22 projects from the tensioning/twisting unit 15, 17. To this end the following description, whilst directed to an individual wire 20, may equally apply to a wire rope 22. It will be appreciated that the pre-coating twisting unit may be combined with the tensioning unit, or be a separate device within the process. The wire 20 passes through a surface coating section 30 which is, in one embodiment, an electrolytic process whereby a supply of nickel coated diamond particles 35 is provided to a chamber 30 with an electrolytic fluid supplied to the chamber 30 and recycled 40. Prior to the surface coating section 30, the wire may be pass through a treatment section for removing unwanted materials from the wire surface.

The wire 20, which is magnetized to attract the nickel coated diamond particles, passes through the electrolytic fluid and has adhered to it the diamond particles with a consequential thin nickel coating. The wire then passes through a wash and rinse arrangement 45 before arriving at the nickel coating stage 50 whereby a further electrolytic process places a nickel coating of a specified thickness onto the wire. The electrolytic fluid is again supplied and recycled by a replenishing tank 55. In one embodiment, parallel strands of coated wire may be twisted 47 to form a wire rope before entering the nickel coating stage 50, and so upstream, individual wires may be coated with grit prior to twisting of the coated wires and then twisting and nickel coating the twisted wires to form the coated wire rope. The diamond and nickel coated wire or wire rope is then passed through a wash and rinse tank 60 before being spooled on the end reel 70 for delivery to an end user. By replacing the wire 20 with a wire rope 22 the resulting product is a coated wire rope which includes sufficient strength to be used in a variety of different applications. By varying the number of wire strands within the wire rope, the coated product may be designed for a specific application.

As to the specific number of wire strands within the wire rope, this may be as few as two strands, or as many as five strands, or even 25 strands in order to achieve the wire rope prior to the coating process. In addition to the enhanced strength, a wire rope may provide a different abrasion profile on the basis that the outer surface may have marginal peaks and troughs corresponding to the multiple wire strands as compared to the substantially cylindrical peripheral surface of a single strand. This may then provide advantages in applying points of concentration to speed the abrasion process.

Further, a wire rope may progressively break as individual strands break and thus allowing greater longevity. This may also reduce waste of the profiles being cut as a broken wire strand for a single wire application may occur in mid cut and thus not only resulting in the disposal of the wire but may result in the disposal of the object undergoing the sawing process. A wire rope having a progressive breakage is therefore likely to prevent such wastage as compared to the catastrophic breakage of a single strand. Further, by providing a wire rope, ends of the wire rope may be braided together so as to provide an endless loop. This would only be possible for a single wire strand if a butt joint were possible, however, the veracity of such a joint precludes the use of an endless loop cutting band.

It will be appreciated that the range of diameters suitable for the wire rope will be broad and may be as small as 100 microns and as large as 2 millimetres with intermediate sizes of 250 and 500 microns. The diamond particle size for the abrasive coating may be 10, 40, 100 or even 200 micron size particles depending upon the diameter of the wire rope and the intended application.

In a further embodiment, rather than coating the wire rope, individual wire strands may be coated first and then twisted so as to create a wire rope of coated wire strands as compared to the previous embodiment being a coated wire rope. Details of these embodiments will be discussed with reference to Figures 2A to 2C.

With reference to Figure 1 , and the above embodiment, rather than the twisting unit 17 there may instead be a twisting unit 65 located adjacent to the end reel 70 for combining the parallel wire strands into a wire rope just prior to spooling onto the end reel. In a third embodiment, coated wire strands may be spooled onto the end reel 70 for later twisting and thus in this embodiment, Figure 1 may omit the twisting stations 17 and 65. Figure 2A shows a longitudinal view of a wire rope 75 having a peripheral abrasive surface 80.

This may be achieved in at least two different ways with Figure 2B showing a wire rope 85 having individual wire strands 90 with a coating 95. In the embodiment of Figure 2B, the individual wire strands have received a coating and are then subsequently twisted into the wire rope 85 to achieve the desired cutting wire. As mentioned, the twisting which would occur after the coating process may occur in line with the coating process such as shown in Figure 1 having a twisting unit 65 adjacent to the end spool. Alternatively, the wire rope 85 may be twisted at a later time from a plurality of end spools as a secondary process.

In an alternative embodiment, the internal wire strands 92 defined as not having an exposed peripheral surface that may aid in the cutting process may be uncoated so as to save cost of material. According such uncoated wire strands may be introduced into the twisting device from a different spool. Similarly, the internal strand may be of a different material having high tensile strength as compared with the coated wire strands, and thus adding further to the strength of the cutting wire. Figure 2C shows an alternative arrangement whereby the wire rope 100 comprises a plurality of wire strands 105 to which is applied a coating 1 10. With reference to Figure 1 , this would be an arrangement whereby the uncoated wire strands are twisted by a twisting unit 17 and therefore do not require the end twisting unit 65. In this arrangement the coating is applied to the uncoated wire rope and subsequently spooled as a coated wire rope as compared to the embodiment of Figure 2B having a wire rope of coated wire strands.

To preserve the generality of the invention, a general term of element may substitute for a wire strand or a wire rope, subject to the embodiment. Thus, where the invention could include a wire strand or a wire rope, the term element may be substitute so as to depict either case.