WO2017016622A1

WO2017016622A1 - Diamond wire with pearls or beads applied directly to its surface

Info

Publication number: WO2017016622A1
Application number: PCT/EP2016/001010
Authority: WO
Inventors: Sergio CRESSINA; Denis CUSINATO
Original assignee: Ferriera Di Cittadella S.P.A.
Priority date: 2015-07-30
Filing date: 2016-06-16
Publication date: 2017-02-02

Abstract

A diamond wire (10) for cutting blocks of marble, granite and stone materials in general and different materials, comprises a steel cable (12) of several strands provided with a plurality of beads (14) axially perforated. These beads are strung on the cable itself and suitably spaced from each other depending on the type and properties of the material to be cut. The beads (14) are made of plastic polymers impregnated with synthetic diamond granules and are bound to the cable (12) by means of a self-locking function.

Description

"Diamond wire with pearls or beads applied directly to its surface"

Description

This invention relates to a diamond wire with pearls applied direcdy to its surface.

More particularly, this invention relates to a diamond wire for cutting and squaring marble, granite and stone materials in general and different materials, in which the pearls or beads are formed by cylinders impregnated with synthetic diamonds, without any metal support and bound direcdy to the surface of the wire itself.

It is known that, for sawing blocks or slabs from blocks of marble and granite and for cutting stone materials in general, diamond wires are used, moved by special mono- or multi-wire machines. On the diamond wires are inserted and fixed multiple small cylinders suitably spaced from each other, generally called "beads", the surface of which is made abrasive by the presence of granules of synthetic diamonds. A traditional pearl or bead comprises a cylindrical steel support, called rivet or pin, along the surface of which is a crown constituted by sintered metal powders, impregnated with said synthetic diamond granules. The beads so produced are strung and distributed in a regular manner on a steel cable of several strands, to which they are fixed by means of the plastic coating process that covers the cable itself. An example of a diamond wire of this type is described in Patent US 20130061731 in which the beads, which are shaped internally and externally, are threaded on the cable and covered with a plastic film that prevents axial movement and rotation. Another known solution, described in US 7089925, provides that the abrasive material of which the beads are provided is made integral with the outer surface of the rivet of the same, by brazing, with the addition of a brazing alloy.

In both these known solutions, the beads thus comprise the traditional rivet or pin, to which the abrasive material is fixed directly or indirectly,

The use of the rivet or pin for the realisation of the known beads determines several major drawbacks.

In the first place, it constitutes a significant extra cost, being among other things usually realised with expensive mechanical machining; in addition, the use of the rivet can give rise to thermal shock by brazing during its fixing to the diamond crown of the bead.

Additionally, the rivet or pin, consisting of a cylindrical metal support, causes a considerable increase of the external diameter of the bead as a whole, resulting in a greater force being exerted on it during movement to make the cut and, in parallel, reduced durability of the diamond wire as a whole.

The purpose of this invention is to overcome the drawbacks listed above.

More particularly, the purpose of this invention is to provide a diamond wire for cutting and squaring marble, granite and stone materials in general and different materials, in which the multiple beads, without the rivet, are fixed direcdy to the outer surface of the wire itself. A further purpose of the invention is to provide a diamond wire for cutting and squaring marble, granite and stone materials in general and different materials, with beads of small diameter, significantiy less than conventional ones provided with rivet or pin.

A further purpose of the invention is to make available to users a diamond wire for cutting and squaring marble, granite and stone materials in general and different materials suitable to ensure high strength, cutting quality and reliability over time, such as to be easily and economically produced.

These and still other purposes are achieved by the diamond wire of this invention according to the main claim.

The constructive and functional characteristics of the diamond wire of this invention will be better understood from the following detailed description, wherein reference is made to the accompanying drawings that illustrate a preferred and non-limiting embodiment and in which:

Figure 1 schematically represents the diamond wire of this invention, with one of the multiple pearls strung on it and fixed; Figure 2 shows schematically, in a front perspective view, one of the pearls combined with the diamond wire of this invention.

With reference to the above figures, the diamond wire of this invention, indicated in its entirety with 10 in Figure 1, which schematically shows a section of it, comprising a very strong steel cable 12 with several strands, very durable, multi-strands, also called rope; on it are strung the beads 14, one of which is illustrated in Figure 2, made of synthetic material of the plastic polymer type. In particular, the material belongs to families of advanced chargeable plastic polymers suitable to retain powders or granules of synthetic diamonds with which they are impregnated and that provide adequate mechanical and abrasion resistance during cutting. The individual beads 14 define a cylindrical shape and are provided with an axial through hole through which they are strung on the steel cable 12 at a predefined distance from each other, based on the type and properties of the material to be cut. On the latter, said beads are fixed directly by means of a self-locking function, which is realised by the compression due to the shrinkage of the plastic polymer material constituting the beads following a thermal- mechanical treatment. This treatment preferably is carried out on known systems of plants like furnaces and injection-compression machines, at temperatures approximately between 250 °C and 600 °C.

Doing so avoids recourse to conventional rivets and pins to support the abrasive material, with considerable advantages both in terms of production costs and cutting effectiveness. Under the latter aspect, it should be considered that the individual beads 14, since without rivet, can be made with smaller diameters than the known beads that, instead, comprise this rivet. In fact, the absence of the rivet makes it possible to appreciably reduce the outer diameter of the pearl for the same diameter of rope or cable used; in fact, beads can be made as small as 3 mm and this translates into a lesser rotation effort during cutting and, consequently, longer life of the diamond wire 10 as a whole, as well as in a saving of cutting system and energy costs, as well as in a lower environmental impact due to the lower amount of production scrap.

As can be seen from the foregoing, the advantages achieved by the invention are clear.

In the diamond wire 10 of this invention, the individual beads 14 made of plastic polymers impregnated with synthetic diamond granules are without rivets and are strung on a steel wire 12 to which are fastened by means of a self-locking function. Moreover, this solution avoids problems arising from possible thermal shock to the materials due to brazing, which could limit the effectiveness of the diamond.

Although the invention has been described above with particular reference to an embodiment, provided by way of non-limiting example, many modifications and variations will be apparent to a person skilled in the art in light of the above description. Therefore, this invention intends to embrace all the modifications and variants falling within the scope of the following claims.

Claims

1. A diamond wire (10) for cutting blocks of marble, granite and stone materials in general and different materials, comprising a steel cable (12) of several strands provided with a plurality of beads (14) ties axially perforated, threaded onto the cable itself and suitably spaced from each other, characterised in that the beads (14) are made of plastic polymers impregnated with synthetic diamond granules and are bound to the cable (12) by a self-locking function.

2. The diamond wire according to claim 1, characterised in that the self-locking function of the beads (14) on the steel cable (12) is achieved by the compression due to the shrinkage of the plastic polymer material constituting the beads following a thermal- mechanical treatment.

3. The diamond wire according to claim 2, characterised in that said thermal-mechanical treatment is carried out on on plants like furnaces and injection-compression machines.

4. The diamond wire according to claim 3, characterised in that, during the heat treatment, the temperature to which are subjected the beads (14) threaded onto the steel cable (12) is between 250 °C and 600 °C.