APPARATUS AND METHOD FOR MANUFACTURING TUBULAR SUPPORTS OF DIAMOND BEADS OF A CUTTING WIRE USABLE FOR CUTTING STONE MATERIAL, AND CUTTING WIRE OBTAINED BY SAID APPARATUS AND METHOD

5 Field of invention

The present invention is generally applicable to the technical field of the working of stone materials, and particularly relates to a method for manufacturing tubular supports for the diamond beads of a wire for cutting blocks of stone material, such as stone, marble, cement, granite and the like.

10 The invention also relates to a tubular support obtainable by this method.

The invention also relates to an apparatus for manufacturing such tubular supports.

The invention also relates to a method for manufacturing the cutting wires that include such tubular supports.

The invention also relates to a cutting wire that includes such tubular supports, as well as a

15 machine for cutting stone material comprising such a wire.

Background of the invention

Several wires are known for cutting blocks of stone material, such as stone, marble, concrete and the like. These wires are generally wound on drums or pulleys, which are rotatably moved to transfer a tangential motion to the wire and promote its penetration into the stone material to be 20 cut.

For example, cutting wires for stone material are known from JP9239721, DE3805405, JP3281118 and EP0718414.

In particular, WO02/04160 describes a wire rope comprising a support on which are fixed a plurality of beads and a plurality of spacer elements in plastic material interposed between the beads 25 to keep them appropriately spaced apart each other. Each bead has a hollow cylinder fixed to the

supporting rope and a peripheral annular member in diamond material for cutting the stone material.

Moreover, WO2012/052952 describes a wire for cutting stone material comprising a support rope having a plurality of diamond beads susceptible to interact with the stone material to cut it.

30 Each diamond bead comprises a metal tubular support externally to which an outer annualr member

made of metal alloy and diamond powder is mounted. During construction of the wire, each part of the support rope free from the diamond beads is coated by at least one spacer element of polymeric material applied by hot injection molding, having the purpose to keep unaltered the mutual distance between the diamond beads. Both the above known embodiments comprise a plurality of spacer elements in polymeric material, having the purpose of keeping unaltered the original position of the diamond beads. To increase the effectiveness of the spacer elements it is useful that during the molding step the polymeric material penetrates between the support rope and the diamond bead.

In order to increase the penetration of the polymeric material, the metal tubular support, which according to the prior art is generally made from a metal bar suitably cut to the desired lenght, is internally threaded. The grooves of the thread, lying on the inner wall of the metal tubular support, increase the penetration of the polymeric material between the rope and the tubular support.

An apparent drawback of these known solutions is the fact that the thread is to be made on each tubular support only after the cutting thereof from the metal bar. The manufacturing process of the finished tubular support, which apparently must be carried out in a discontinuous manner, is therefore long and economically disadvantageous.

Due to the stresses during the cutting, the internal thread of the tubular support of each diamond bead further promotes a spiral motion of the bead along the rope. This spiral motion causes an undesired shift of each bead, with consequent loss of the original distances between the beads and the reduction of the effectiveness and cutting uniformity of the wire. Therefore, the internal thread imparts to the bead a motion along the rope.

A further drawback of the known solutions is the fact that the spiral motion of the beads cause localized and premature wear, reducing the overall duration of the cutting wire.

Summary of the invention

An object of the present invention is to overcome at least partly the above mentioned drawbacks, by providing a method for manufacturing tubular supports for the diamond beads of a cutting wire of highly efficiencient and relatively cost-effective.

Another object of the invention is to provide a wire with high wear resistance and which allows relatively large maintenance intervals.

Another object of the invention is to provide cheap tubular supports for the diamond beads of a cutting wire cost.

Another object of the invention is to provide a wire whose diamond beads keep unaltered their original reciprocal distances for long periods, thus dramatically reducing any movement thereof along the rope.

Another object of the invention is to provide a method for manufacturing the tubular supports for the diamond beads of a cutting wire that is economically advantageous.

A further object of the invention is to obtain a method for manufacturing the tubular supports for the diamond beads of a cutting wire that is relatively simple to implement and allows providing wires with high levels of quality construction.

A further particular object is to provide a wire which has reduced localized wear.

These objects, as well as others that will appear more clearly hereinafter, are achieved by a method for manufacturing tubular supports for the diamond beads of a cutting wire according to claim 1.

In a further aspect, an apparatus for manufacturing tubular supports for the diamond beads of a cutting wire according to claim 17 may be provided.

In a further aspect, a tubular support for the diamond beads of a cutting wire according to claim 31 may be provided.

In a further aspect, a cutting wire may be provided according to claim 34.

In a further aspect, a machine for cutting slabs of blocks of stone material according to claim 35 may be provided.

In a further aspect, a method for manufacturing a cutting wire according to claim 36 may be provided.

Advantageous embodiments of the invention are defined in accordance with the dependent claims.

Brief description of the drawings

Further features and advantages of the invention will appear more evident upon reading the detailed description of some preferred, non-exclusive embodiments of a method and/or an apparatus according to the invention and of some preferred embodiments of a wire and of a machine according to the invention, which are described as non-limiting examples with the help of the annexed drawings, in which:

FIG. 1 is a side view of some details of a wire 1;

FIG. 2 is a sectional and enlarged view of some details of FIG.l;

FIG. 3 is an enlarged schematic view of a first example of laminar metallic element 6 obtained in an intermediate step of the manufacturing process;

FIG. 4 is a schematic and enlarged view of a second example of laminar metallic element 6 obtained in an intermediate step of the manufacturing process;

FIG. 5 is a schematic view of a machine 14 for cutting blocks of stone material B that includes the wire 1;

FIG. 6 is a partially sectioned and enlarged view of some details of FIG.5;

FIG. 7 is a schematic view of an embodiment of manufacturing process of the supports 4 starting from a metal foil 13;

FIGs. 8, 9 and 10 are schematic views of some embodiments of the supports 4. Detailed description of some preferrred embodiments

With reference to the above figures, a method and an apparatus are described for manufactuing tubular supports 4 susceptible to support the respective diamond cutting members 3 to obtain diamond beads 5 which are to be coupled to a flexible support structure 2 for manufacturing a wire 1 for cutting blocks B of stone material, such as stone, marble, granite, concrete and the like.

In a per se known manner, the wire 1 can be manufactured by a method which comprises a first step 1) of providing a flexible support structure 2, which may be, by way of non-limiting example, a cable or a rope in metallic material, e.g. steel.

A second step 2) of providing a plurality of diamond beads 5 may further be provided, each diamond beads 5 comprising in a per se manner a tubular support 4 and a diamond cutting member 3.

Each cutting member 3 is susceptible to interact with the stone material to cut it.

Each tubular support 4 may be susceptible to support a corresponding diamond cutting member 3 and to be interposed between the latter and the flexible support structure 2. The diamond cutting members 3 may be obtained in different ways, for example by sintering, and may include at least a part of its content derived from diamond or like material.

In a per se known manner, each diamond cutting member 3 may be put externally to a corresponding tubular support 4, so as to obtain the diamond beads 5.

It is understood that for the purpose of manufacturing the wire 1 diamond beads 5 already assembled may be used without departing from the scope of protection defined by the appended claims. In this case, the manufacturing method of the wire 1 may for example include a collection step of the diamond beads 5 already assembled from a storage site.

The manufacturing method of the wire 1 may then include a subsequent step 3) of inserting the diamond beads 5 on the flexible support structure 2.

In particular, the diamond beads 5 may be positioned at predetermined mutual distances. By suitably choosing the distances between the diamond beads 5, portions 8 of the flexible support structure 2 free from the latter diamond beads 5 may be provided, i.e. portions of the of the flexible support structure 2 not occupied by diamond beads 5.

A further step 4) may then be provided of manufacturing spacer elements 9 in thermoplastic polymeric material around the flexible support structure 2, for example by injection molding of polyurethane. More in detail, the spacer elements 9 may be injection molded externally to the flexible support structure 2 in correspondence of its free portions 8. In this manner, the spacer elements 9 interpose between the diamond beads 5 to mutually block them. In this step, the polymeric material interposes, inter alia, between the flexible support structure 2 and the tubular support 4.

Advantageously, the step 4) of manufacturing the spacer elements 9 may also include the molding of a layer 9' of polymeric material also externally to the diamond beads 5 already positioned on the support structure flexible.

Suitably, each of the tubular supports 4 may be manufactured by the sequence of steps described below.

A first step i) may include the provision of a metal foil 13, which may be substantially flat and may have a generally rectangular elongated shape along a longitudinal axis X. The metal foil 13 may have a pair of edges 7, 7' on opposite sides with respect to the longitudinal axis X.

It is understood that, although in this description a single foil 13 is mentioned, more metal foils may be provided, for example arranged in series or in parallel, without departing from the scope of protection defined by the appended claims.

As used herein, the term "providing" and derivatives thereof designates the preparation of a relevant component for a relevant process step, including any preventive treatment designed for optimal performance of such relevant step, from simple collection and possible storage to thermal and/or chemical and/or physical pre-treatments or the like.

The step i) of providing the metal foil 13 may include the unwinding thereof from a reel 60 on which it is wound.

The step i) of providing the metal foil 13 may further comprise a step i") of grinding the edges

7, 7' by suitable grinding means 57, for example a pair of grinding cylinders or discs or a pair of grinding tools. This way, the edges 7, 7' became mutually complementary shaped, for example a substantially rectilinear or any curvilinear form, provided that the edges 7, 7' are complementary shaped.

Although in the present description it is assumed that the step i") of grinding the edges 7, 7' takes place subsequently to the unwinding of the metal foil 13 from the reel 60 on which it is wound, it is understood that the grinding step, if any, may be done at any time of the process, provided that it is accomplished before the joining step of the edges 7, 7', without departing from the scope of protection defined by the appended claims.

Suitably, the step i) of providing the metal foil 13 may also comprises a step i') of providing on its operative face 10 with a plurality of grooves or recesses 11 by suitable means 53 for manufacturing thereof. For example, the manufacturing means 53 of the grooves and/or recesses 11 on the operative face 10 may include a knurling device so as to obtain a knurl thereon.

As used herein, the term "grooves" or derivaties thereof means an elongated aperture, of any size.

As used herein, the term "recesses" or derivative thereof means a recessed or empty portion of the relevant surface, of any shape or size, provided they it has is not an elongated shape.

FIG. 8 shows an example of a tubular support 4 manufactured by a metallic foil 13 which includes exclusively grooves 11, in the form of a knurl.

In FIG. 9 shows an example of a tubular support 4 manufactured by means of a metallic foil 13 that includes only recesses 11, in the form of hexagonal openings.

FIG. 10 shows an example of a tubular support 4 manufactured by means of a metallic foil 13 which includes both recesses and grooves 11.

The grooves and/or recesses 11 may be manufactured in any manner on the operative face

10. For example, they may be made by sandblasting of the operative face 10 or by treatment thereof with an acid, so as to roughen the same operative face 10.

Alternatively, the grooves and/or recesses 11 may already be provided on the operative face 10 of the metal foil 13, as for example previously made or otherwise originally present thereon.

In any case, upon the next bending step ii) the metal foil 13 includes the operative face 10 with the grooves and/or recesses 11.

Subsequently to the first step i), a second step ii) may take place of bending the metal foil 13 around the axis X up to the reciprocal matching of the complementary shaped edges 7, 7'.

To this end, suitable bending means 54 may be provided, for example a bending machine for metal sheet, represented in FIG. 8 with a dotted line.

Advantageously, the step ii) may be accomplished by bending the metal foil 13 in correspondence of the operative face 10 provided with grooves and/or recesses 11, so that the latter defines the inner wall 12 of the tubular support 4.

This way, the grooves and/or recesses 11 may be manufactured on the inner wall 12 of the tubular support 4, so as to define a plurality of receptacles 11' susceptible to house the polymeric material of the spacer elements 9 during the above step 4) of manufacturing thereof, for example by injection molding of polyurethane.

If the operative face 10 includes only grooves 11, the receptacles 11' on the inner wall 12 of each tubular support 4 are annular shaped.

In this case, in order to prevent the diamond beads 5 to advance along the flexible support structure 2 upon the interaction thereof with the block B to be cut, the annular receptacles 11' may be non-parallel to the axis X and mutually apced apart and disconnected so as not to define a helical pattern.

In particular, the grooves 11 may extend along one or more directions inclined with respect to the axis X.

Suitably, the grooves 11 may further have direction substantially orthogonal to the axis R, as shown in FIG. 4. In this way, the direction of the grooves 11 does not impart a motion to the tubular support 4 upon the interaction with the flexible support structure 2 during use.

Therefore, the direction of the grooves 11 allows to obtain a substantial reduction of the movement of the diamond beads 5 along the flexible support structure 2, giving the wire 1 high resistance to wear and, more in general, greater duration.

Subsequently to the bending step ii), a third stage iii) may take place of permanent joining the complementary shaped edges 7, 7' so as to obtain the tubular support 4.

Suitably, the permanent joining step iii) of the com plementary shaped edges 7 may be accom plished by welding or hot or cold pressure bonding.

For this purpose, suitable means 55 for permanently joining the edges 7, 7' may be provided, which may include for example a welding or bonding device.

This way, a semifinished metal tube 4' may be obtained, which has substantially the same length of the metal foil 13 and may define an axis X' substantially parallel to the longitudinal axis X thereof.

Suitably, to correct any deformation due to the permanent joining step iii), a step iii') may be provided of calibration of the diameter of the semifinished metal tube 4'. For this purpose, suitable calibration means 59 may be provided, which may include for example a drawing device.

Subsequently to the permanent joining step iii) a fourth step iv) may take place ofcutting of the sem ifinished metal tube 4' 'in order to obtain the tubular supports 4. For this purpose, suitable cutting means 61 may be provided, for example a disc or water cutting device.

Suitably, subsequently to the step iv) a step iv') may take place of finishing the tubular elements 4. To this end, suitable finishing means 62 may be provided, which may include for example a deburring device.

In a preferred but not exclusive embodiment, for each metal foil 13 on the reel 60 all the above steps may take place continuously.

In particular, the step i) of providing the metallic foil 13, the step ii) of bending thereof and the step iii) of permanent joining the edges 7, 7' may advantageously take place sequentially in continuous.

Suitably, also the step iv) of cutting the semifinished metal tube 4' to obtain the tubular supports 4 may be accomplished in continuous after the step iii) of permanent joining of the edges 7, 7'.

For this purpose, suitable means for continuously feeding the metal foil 13 on the reel 60 from the inlet 51 of the folding means 54 to the inlet of the cutting means 61 may be provided, via the possible grinding means 57, the possible grooves and/or recesses 11 manufacturing means 53, the possible calibration means 59 and/or the possible finishing means 62.

These continuous feeding means, not represented in the figures because per se known, may include conveyor belts and/or rollers, motorized or driven. Carrier means of the metallic foil 13 through the various stations of the apparatus may further be provided.

The process may further be inherently continuous without departing from the scope of protection defined by the appended claims. In other words, only some steps may be accomplished sequentially in continuous, while others may be made singularly.

For example, the step i) of providing the metallic foil 13, the bending step ii) thereof and the step iii) of permanently joining the edges 7, 7' may take place sequentially in continuous. In this case, the semifinished metal tube 4' at the outlet of the permanent joining means 55 may be wound on a special reel and stored for the next cutting step iv) thereof, which may for example take place in another section of the apparatus or in another apparatus separate from the one in which the first three steps have been accomplished or in the same apparatus but the next day.

It is apparent that in any case the length of the starting metal foil 13 is greatly higher than that of the tubular supports 4, for example in a ratio 100:1 or more.

As used herein, the term "length greatly higher" and derivatives thereof means a ratio between the lengths of at least 30:1.

Thanks to the above features, it will be possible to minimize the time and cost of production of the tubular supports 4.

In fact, the production process of the finished tubular support 4 may be accomplished in a substantially continuous manner, with apparent advantages when compared to the production processes of the prior art.

Thereafter, a wire 1 for cutting blocks B of stone material is described, which may preferably be manufactured by the above method. The wire 1 may comprise a flexible support structure 2 defining an axis L and a plurality of diamond beads 5 inserted on the flexible support structure 2.

Each diamond bead 5 may include a tubular support 4 and a cutting member 3 in diamond material externally coupled to the tubular support 4 and susceptible to interact with the stone material to cut it.

Each tubular support 4 may have a pair of edges 7, 7' with a mutual complementary shape joined by a permanent joining, for example a weld or a bonding bead, and may have an inner wall 12 with the above described receptacles 11'.

The diamond beads 5 may be positioned on the flexible support structure 2 at predetermined mutual distances. The wire 1 may further comprise a plurality of spacer elements 9 in thermoplastic polymeric material, for example polyurethane, injection-molded between the diamond beads 5 to mutually block them.

As shown in FIG. 5, a machine 14 for cutting blocks of stone material B may comprise a frame 15, preferably of the portal-like type, at least one wire 1 for the cutting of the blocks B and at least one pair of devices 16 mounted on the frame 15 for supporting and moving the wire 1, for example drums and/or pulleys.

The wire 1 may be obtained by the above described method and/or apparatus. The machine 14 may have a plurality of wires 1 mounted on respective supporting and moving devices 16 so as to be substantially parallel to each other, thus allowing the cut into slabs of the blocks B of stone material.

From the above description, it is apparent that the invention fulfils the intended objects. The invention is susceptible to many changes and variants. All particulars may be replaced by other technically equivalent elements, and the materials may be different according to the needs, without exceeding the scope of the invention defined by the appended claims.