WO2012110976A1

WO2012110976A1 - Device for tensioning the cutting wires in a multiwire machine for cutting slabs from blocks of stone material

Info

Publication number: WO2012110976A1
Application number: PCT/IB2012/050708
Authority: WO
Inventors: Eddy LIEVORE
Original assignee: Breton S.P.A.
Priority date: 2011-02-17
Filing date: 2012-02-16
Publication date: 2012-08-23
Also published as: BR112013012762A2; IT1404100B1; ES2437139B1; ITVI20120038A1; ES2437139R1; ITVI20110029A1; ES2437139A2

Abstract

A device for tensioning the cutting wires (20) in a multiwire machine (1) for cutting slabs from blocks (B) of stone material. The device comprises one support element (30) including one annular seat (35) for housing a respective cutting wire (20) and actuating means acting on the support element (30) to promote the sliding thereof along a predetermined direction (Y), thus tensioning the respective cutting wire (20). The actuating means include at least one pneumatic cylinder (60, 60') with a rod (51, 51') having the free end (56, 56') operatively connected with the support element (30). A multiwire machine (1) including one or more of these devices.

Description

DEVICE FOR TENSIONING THE CUTTING WIRES IN A MULTIWIRE MACHINE FOR CUTTING SLABS FROM BLOCKS OF STONE MATERIAL

DESCRIPTION

Field of the invention

The present invention generally relates to the technical field of the working of stone materials, and particularly concerns a device for tensioning the cutting wires in a multiwire machine for cutting slabs from blocks of stone material, as well as a multiwire machine comprising such device.

Background of the invention

M ultiwire machines for cutting slabs from blocks of stone material, such as stone, marble, concrete agglomerates and the like are known, which comprise a portal like frame on which the diamond cutting wires are mounted. The last ones, as known per se, penetrate into the block of stone material by translating along a substantially vertical direction, thus reducing it into slabs. The thickness of the slabs obtained from the cut is determined by the distance between two subsequent wires.

As known per se, the wires are wound around one or more elements for supporting thereof, generally drums or assemblies of juxtaposed pulleys, suitable to put the wires into rotation in order to facilitate the penetration thereof into the block. To allow this action, the multiwire machine comprises one or more devices suitable for tensioning the cutting wires.

The known devices of this type generally comprise actuating means of oil hydraulic type acting on the support element, whether a drum or a pulley, to promote the sliding thereof along a predetermined direction.

This known solution, even being effective from a functional point of view, can be improved in terms of cost-effectiveness, ease of maintenance and running and in terms of safety in case of breaking of one or more of the wires.

Summary of the invention

Object of the present invention is to at least partially overcome the above described drawbacks by providing a device for tensioning the cutting wires in a multiwire machine for cutting slabs from blocks of stone material having excellent efficiency and comparatively low costs.

Another object of the invention is to provide a device which allows a relative flexibility in use. Another object of the invention is to provide a device which allows a quick and simple maintenance.

Another object of the invention is to provide a device which results to be safe in case of breaking of one or more wires.

These and other objects, as better explained hereafter, are fulfilled by the device for tensioning the cutting wires in a multiwire machine for cutting slabs from blocks of stone material having one or more of the features herein described and/or shown.

Appropriately, the device may comprise at least one support element which may include one or more annular seats to house respective cutting wires. This support element may include, respectively consist of, one or more drums or one or more pulleys.

Moreover, the device may include actuating means of the pneumatic type, for example a pneumatic actuating unit, acting on the above mentioned at least one support element to promote the sliding thereof along a predetermined direction, so as tension the cutting wires wound thereon. Advantageously, the device may further comprise a pneumatic circuit for the fluidic connection of the pneumatic actuating means to means for supplying air in pressure therein.

Preferably, the actuating means may comprise one or more pneumatic cylinders with respective one or more rods having the free end operatively connected with the at least one support element.

In a preferred, non-exclusive embodiment of the invention, the pneumatic circuit may include means or a unit for detecting a variation of the air flow therein, for instance a variation of the air flow.

In this way, it will be very easy and practical to detect the breaking of one or more wires, so that the device results very safe for the operators who work therewith.

Appropriately, the device may comprise blocking means selectively activatable by the detecting means upon the detection of a variation within the bypass circuit, for example the variation of the air flow, to act on the motor means of the multiwire machine, in such a manner to block the movement of the cutting wires.

This configuration makes the device even safer, as the blocking of the cutting wires takes place automatically upon detecting the flow variation in the bypass circuit.

In a preferred, non-exclusive embodiment of the invention, independently from the presence or not of the above means or unit for detecting a variation of the air flow within the pneumatic circuit, the actuating means or the actuating unit may comprise one pair of pneumatic cylinders and a connecting element having at least one first edge portion operatively connected with the at least one support element and at least one second edge portion operatively connected with both the rods of the pair of pneumatic cylinders in correspondence of respective connecting areas.

Appropriately, the connecting areas may be placed onto the at least one second edge portion of the connecting element on opposite sides with respect to a median plane interposed between the connecting areas passing through the at least one second edge portion and substantially orthogonal to the plane defined by the at least one annular seat of the drum or of the at least one pulley.

As used herein, the expression "median plane" interposed between two points is intended to indicate a plane interposed between the two points in a substantially central position, so to result substantially equidistant from the two points.

Advantageously, the at least one second edge portion of the connecting element may comprise one pair of second ends, each one operatively connected with the respective rod. The connecting areas may consist of these ends.

Thanks to one or more of the above features, the device results mechanically easier, cheaper and quick and simple to maintain with respect to the prior art devices.

On the other hand, a multiwire machine for cutting slabs from blocks of stone material is provided, including the tensioning device having one or more of the features herein described and/or shown.

Advantageous embodiments of the invention are defined according to the annexed claims.

Brief description of the drawings

Further features and advantages of the invention will appear more evident upon reading the detailed description of a preferred, non-exclusive embodiment of a device for tensioning the cutting wires in a multiwire machine for cutting slabs from blocks of stone material according to the invention, which is described as non limiting example with the help of the annexed drawings, in which:

FIG. 1 is a schematic view of a multiwire machine 1 for cutting slabs from blocks B of stone material including a plurality of tensioning devices 50;

FIG. 2 is a schematic view of a tensioning device 50 including a plurality of pulleys 30 mounted on the frame 10 of the multiwire machine 1, wherein the frame 10 is represented with dashed line;

FIG. 3 is a schematic view of a single tensioning device 50;

FIG. 4 is a schematic view of some details of the multiwire machine 1, in the resting condition;

FIG. 5 is a schematic view of some details of the multiwire machine 1, in the working condition;

FIG. 6 is a schematic view of some details of the multiwire machine 1 upon breaking of a cutting wire 20;

FIG. 6a is an enlarged view of some details of FIG. 6;

FIG. 7 is a schematic view of some details of an alternative configuration of the multiwire machine 1, in the working condition.

Detailed description of some preferred embodiments of the invention

Referring to the above figures, a multiwire machine 1 for cutting slabs from blocks B of stone material is described.

The machine 1 has several parts or elements equal to each other or anyway substantially similar. Unless differently specified, these parts or elements are singularly described and/or indicated with a single number, thus meaning that the described and/or shown features are common to all other parts or elements equal or anyway substantially similar.

As known per se, the above machine 1 comprises a frame 10, a plurality of diamond cutting wires 20 and at least one pair, preferably a plurality, of support elements 31, which may be drums or a plurality of pulleys, mounted on the frame 10 for supporting and moving the above cutting wires 20.

As known per se, each support element 31 includes one or more annular seats to house a respective cutting wire 20. Moreover, the support elements 31 are suitable to slide along the direction X, which may be substantially vertical, to penetrate into the block B and reduce it into slabs.

For this purpose, motor means may be provided, generally indicated with 40, which may be operatively connected to one or more of the support elements 31 for rotating thereof around their axis, so moving the cutting wires 20. I n this way, instant by instant, an active portion 21 is defined for each of them, facing the block B to be cut and intended to penetrate therein, and a returning portion 22, opposite thereto.

Advantageously, the machine 1 may comprise a plurality of devices 50 for tensioning the cutting wires 20.

In general, each device 50 may include one or more support elements 30, also having one or more annular seats 35 to house a respective cutting wire 20 and pneumatic actuating means acting thereon to promote the translation of the support elements 30 along the longitudinal direction Y.

Appropriately, each support element 30 may include one or more drums or one or more pulleys.

In a preferred, non-exclusive embodiment of the invention, shown in FIGS. 2 and 3, the actuating means may include one pair of guide elements 51, 5 operatively connected to a support element 30.

In a preferred, non-exclusive embodiment the support element may comprise, respectively may consist of, a pulley 30 having one or more annular seats 35 to house respective cutting wires 20. It is however understood that the device may equivalently include a drum, without departing from the scope of the invention expressed by the annexed claims.

Moreover, the guide elements 51, 5 may comprise, respectively consist of, rods mounted on the multiwire machine 1 so as to slide along predetermined sliding directions Y', Y", which may be parallel to each other. In this way, the rods 51, 51' drive the pulley 30 along the direction Y which may be parallel to the directions Y', Y".

In particular, the rods 51, 5 may be mounted on the machine 1 in such a manner that the directions Y, Y', Y" result substantially orthogonal with respect to the direction X of translation of the cutting wires 20. Alternatively, the rods 51, 5 may be mounted on the machine 1 so that the directions Y, Y', Y" result substantially inclined with respect to the direction X.

The reciprocal operative connection between the rods 51, 5 and the pulley 30 may be ensured by an appropriate connecting element 52.

In particular, the connecting element 52 may comprise, respectively consist of, one pair of facing plates 53, 53', placed on opposite parts of the pulley 30.

Each plate 53 may have a first edge portion 54 operatively connected with the pulley 30 and a second edge portion 54' opposite to the first one operatively connected to the corresponding ends 56, 56' of both rods 51, 51' of the pair of pneumatic cylinders 60, 60' in correspondence of respective connecting areas 55, 55'.

Advantageously, in order to better drive the pulley 30 during its sliding along the direction Y, the connecting areas 55, 55' may be placed on the second edge portion 54' of the connecting element 52 on opposite sides with respect to a median plane π_Μ interposed between the connecting areas 55, 55', passing through the second edge portion 54' and substantially orthogonal to the plane π defined by the least one annular seat 35 by the pulley 30 and/or by the relative annular seat 35.

Moreover, it is understood that in the usual working conditions the plane π defined by the at least one annular seat 35 may be substantially vertical, whereas the median plane π_Μ may be substantially horizontal.

Thanks to this configuration, no other driving means are necessary to drive the sliding of the pulley 30 along the direction Y. In other words, the rods 51, 51' define actuating as well as driving means for the support element 30.

It is understood that the connecting areas 55, 55' and/or the relative rods 51, 51' may be reciprocally superimposed or reciprocally offset.

Appropriately, the connecting areas 55, 55' may be reciprocally superimposed in such a manner that the relative rods 51, 5 define a plane π' substantially parallel to or coincident with the plane π defined by the least one annular seat 35 by the pulley 30 and/or by the relative annular seat 35.

Appropriately, the second edge portion 54' of the connecting element 52 may comprise one pair of ends, each one operatively connected with the respective rod 51, 51'. The connecting areas 55, 55' may consist of these ends.

Preferably, in order to optimize the mechanical stresses of the system, the median plane π_Μ may coincide with the symmetry plane of the first and second edge portion 54, 54'.

Moreover, the second edge portion 54' may suitably comprise one pair of opposite ends 55, 55' defining the above mentioned connection zones.

In a preferred, non-exclusive embodiment of the invention, shown in the FIGS 2 and 3, the connecting element 52 may have a substantially isosceles triangular shape, with a vertex defining the first edge portion 54 and the opposite edge defining the second edge portion 54'. Moreover, the ends of the last one may define the connecting areas 55, 55'.

In this case, the median plane π_Μ defines the symmetry plane of the connecting element 52 substantially orthogonal to the plane π defined by the pulley 30 and/or by the relative annular seat 35.

As used herein, the expression "isosceles triangle" or derivates thereof is intended to indicate a triangle having at least two sides equal to each other. Therefore, for the purpose of the present document an equilateral triangle is an isosceles triangle.

Preferably, the actuating means may include, respectively consist of, one pair of pneumatic cylinders 60, 60', which may be fluidically connected to means for supplying air in pressure therein, for example a compressor 70, by means of a pneumatic circuit 71.

The rods 51, 5 may have the ends 57, 57' operatively coupled with the pneumatic cylinders 60, 60'. In particular, each pneumatic cylinder 60, 60' may comprise a piston 61 tightly sliding therein between a starting end-stroke position, shown in FIG. 4, and a final end-stroke position, shown in FIG. 6. Each piston 61, 61' may be operatively connected to the relative rod 51, 51' in correspondence of the ends 57, 57'.

Each piston 61 may divide the relative cylinder 60 into two variable volume compartments 62', 62", preferably adjacent to each other.

Preferably, the rods 51, 5 may have the same size, and in particular the same length. Moreover, the pistons 61 operatively connected to the rods 51, 51' may appropriately have the same stroke within the respective cylinder 60, 60'.

Advantageously, the pneumatic cylinders 60, 60' may be connected in parallel to each other, in such a manner that the air flow therein is the same. Moreover, the pneumatic cylinders 60, 60' may preferably have the same size, so that the force exerted on the pulley 30 is the same.

Appropriately, the pneumatic circuit 71 may comprise valve means 72 to adjust the air flow into the cylinders 60, 60'.

The valve means 72 may direct the air flow into the two lines 73', 73" of the circuit 71, which may fluidically connect the compressor 70 respectively with the chambers 62' and 62".

In particular, in the first position shown in FIG. 4, which corresponds to the resting position of the multiwire machine 1, the valve means 72 connect the compressor 70 with the chamber 62", so that the piston 61 remains in the starting end-stroke position.

In the second position shown in FIG. 5, which corresponds to the working condition of the multiwire machine 1, the valve means 72 connect the compressor 70 with the chamber 62', so that the air blown by the compressor 70 into the cylinders 60, 60' determines the sliding of the rods 51, 51' along the directions Y', Y", with consequent sliding of the pulley 30 connected thereto and tensioning of the cutting wires 20 inserted in the seats 35.

Advantageously, the circuit 71 may comprise detecting means for detecting a flow variation therein, for example a variation of the air flow.

Appropriately, the detecting means for detecting a flow variation within the circuit 71 may comprise a flow switch 75. Moreover, the detecting means for detecting a variation within the circuit 71 may comprise a concave zone 76 made in each cylinder 60, 60'.

The concave zone 76 may have such size that, when the piston 61 goes to its final end-stroke, the two chambers 62', 62" of each cylinder 60 are in a reciprocal fluidic communication. The line 73" of the circuit 71 has an end 74 connected to the bottom of the concave zone 76, as shown in FIG. 6a.

Upon breaking of a wire 20, the pressure present in the chamber 62' pushes to the final end-stroke the piston 61 and, consequently, the pulley 30 connected thereto. The sudden sliding of the pulley allows an operator to see the breaking, so that he can block the machine to avoid seizures and/or breakings.

Upon breaking of the wire 20, shown in FIG. 6, the fluidic communication which forms between the chambers 62', 62" creates a flow variation within the circuit, which may be detected by the flow switch 75.

Appropriately, blocking means may be provided, for example a microprocessor logic unit 80, connected to the flow switch 75 and activated by the last one upon detecting a variation of the air flow within the circuit 71 to act on the motor means 40 and block the movement of the cutting wires 20, as shown in FIG. 6.

In this way, the device according to the invention results to be very safe in case of breaking of wires 20, because the blocking of the machine is completely automatic.

Furthermore, the microprocessor logic unit 80 may activate alarm means 81 of the visual and/or acoustic type.

A quick exhaust valve 77 may be also provided, which allows to rapidly discharge the circuit 71 in case of need.

Advantageously, all the pneumatic cylinders of the tensioning devices 50 mounted on the machine 1 may be fluidically connected to each other in parallel to the compressor 70. FIG. 7 illustrates an alternative embodiment of the invention, wherein the device 50 includes a single pneumatic cylinder 60 operatively connected to the support element 30, which may consist of one or more drums or one or more pulleys.

It is understood that the support element 30 may include driving means, for example driving rods 58, 58' designed to slidingly move within the frame 10 of the multiwire machine 1 along respective directions Y', Y" substantially parallel to the sliding direction Y of the rod 51 of the single pneumatic cylinder 60, without departing from the scope of the invention.

The pneumatic cylinder 60 may be fluidically connected to the source of air in pressure 70 by means of the pneumatic circuit 71.

In a preferred, non-exclusive embodiment, this embodiment of the invention may include the detecting means 75 and/or the blocking means 80, which may be preferably completely analogous and may work in the same way described above for the embodiment shown in FIGS. 4 to 6a.

The above description clearly shows that the tensioning device and the multiwire machine according to the invention fulfil the intended scopes.

The device according to the invention results to be easier, cheaper and has a simple and quick maintenance with respect to the prior art devices.

Moreover, it results to be safer in case of breaking of the wire, because in this case the rods 51, 5 reach the final end-stroke position, so as to outwardly project the relative pulley 30. Moreover, the blocking means 80 and/or the alarm means 81 are activated.

The tensioning device and the multiwire machine according to the invention are susceptible to many changes and variants, all falling within the inventive concept expressed in the annexed claims. All particulars may be replaced by other technically equivalent elements, and the materials may be different according to the needs, without departing from the scope of the invention.

Claims

1. A device for tensioning the cutting wires (20) in a multiwire machine (1) for cutting slabs from blocks (B) of stone material, the device comprising:

- at least one support element (30) including at least one annular seat (35) for a respective cutting wire (20);

- actuating means acting on said at least one support element (30) to promote the sliding thereof along a predetermined direction (Y), thus tensioning the respective cutting wire (20),

wherein said actuating means include at least one pneumatic cylinder (60, 60') with a rod (51, 51') having the free end (56, 56') operatively connected with said at least one support element (30).

2. Device according to claim 1, wherein said actuating means include one couple of pneumatic cylinders (60, 60'), each of the rods (51, 51') of said couple having a respective free end (56, 56') operatively connected with said at least one support element (30).

3. Device according to claim 2, further comprising a connecting element (52) having a first edge portion (54) operatively connected with said at least one support element (30) and at least one second edge portion (54') operatively connected with both said rods (51, 51') in correspondence of respective connecting areas (55, 55').

4. Device according to claim 3, wherein said connecting areas (55, 55') are placed on said at least one second edge portion (54') of said connecting element (52) at opposite sides with respect to a median plane (π_Μ) which is interposed between said connecting areas (55, 55') and substantially perpendicular to the plane (π) defined by said at least one annular seat (35).

5. Device according to claim 3 or 4, wherein said connecting areas (55, 55') are reciprocally superimposed in such a manner that said rods (51, 51') define a plane (π') substantially parallel to or coincident with the plane (π) defined by said at least one annular seat (35).

6. Device according to claim 4 or 5, wherein said median plane (π_Μ) coincides with the symmetry plane of said connecting element (52) passing through said first edge portion (54) and said at least one second edge portion (54').

7. Device according to claim 4, 5 or 6, wherein said at least one second edge portion (54') includes one couple of opposite ends (55, 55') defining said connecting areas.

8. Device according to claims 6 and 7, wherein said connecting element (52) has a substantially isosceles triangular shape with a vertex defining said first edge portion (54) and the opposite edge defining said at least one second edge portion (54').

9. Device according to one or more of the preceding claims, further comprising a pneumatic circuit (71) for fluidically connecting said at least one pneumatic cylinder (60, 60') and means (70) for supplying air in pressure therein, said circuit (71) including means (75) for detecting an air flow change therein.

10. Device according to the preceding claim, wherein said at least one pneumatic cylinder (60, 60') internally includes a piston (61, 61') operatively connected with said rod (51, 51') to slidably moving between a starting end-stroke position and a final end-stroke position, said at least one pneumatic cylinder (60, 60') and said hydraulic circuit (71) being reciprocally configured so that said detection means (75) detect an air flow change in the circuit (71) when said piston (61, 61') is in the proximity of the final end-stroke position.

11. Device according to claim 9 or 10, wherein the multiwire machine (1) includes motor means (40) for moving the cutting wires (20), the device including blocking means (80) selectively activatable by said detection means (75) upon detection of an air flow change in the circuit (71) and susceptible to act on the motor means (40) to automatically blocking the movement of the cutting wires (20).

12. A multiwire machine for cutting slabs from blocks (B) of stone material, comprising a frame (10) and a plurality of cutting wires (20), the machine further including at least one device (50) for tensioning the cutting wires (20) according to one or more of the preceding claims.

13. Multiwire machine according to claim 12, wherein all the pneumatic cylinders (60, 60') are fluidically connected in parallel with means (70) for supplying air in pressure therein.