WO2003004235A1

WO2003004235A1 - Method and system for dividing blocks of stone into slices using one or more cutting tools

Info

Publication number: WO2003004235A1
Application number: PCT/IB2002/002560
Authority: WO
Inventors: Emilio Brocco
Original assignee: Co.Fi.Plast S.R.L.
Priority date: 2001-07-04
Filing date: 2002-07-02
Publication date: 2003-01-16
Also published as: ITTO20010644A1

Abstract

According to the invention, each block of stone belonging to a plurality of blocks (B1, B4) arranged in sequence is advanced along a line by conveyor means (11, 14, 15, 16, 19) which feed it to an advancement and cutting station (I4), in which at least a closed loop cutting tool (17) is caused to continuously travel in a plane which is essentially vertical between a drive pulley (17.1) and at least a driven pulley (17.2) and makes a corresponding cut in said block with an essentially vertical branch (T1), i.e. in the direction of the height of the block, while the block is advanced continously towards a following unloading station (I5), so that all the blocks belonging to a plurality of blocks of stone (which are fed in sequence and in line along said conveyor means) are divided into slices; this arrangement permitting continous operation in optimal conditions in terms of planarity of each cut and parallelism between several cuts in a same block, when working with several cutting tools, with high specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving cutting efficiency and reducing tool wear.

Description

"METHOD AND SYSTEM FOR DIVIDING BLOCKS OF STONE INTO SLICES USING ONE OR MORE CUTTING TOOLS"

The present invention concerns a method for dividing blocks of stone into slices using one or more cutting tools. The invention also relates to the system for implementing such method.

Sawing machines with one or more cutting tools for dividing blocks of stone into slices are known. It is noted that before division using such machines, the blocks to be cut are advantageously squared into a form which is substantially that of a parallelepiped.

Italian patent 1,281,035 (international publication WO 98/35802) describes a sawing machine of the specified type which is used to divide a block of stone into a plurality of slices by means of several cutting tools. Each cutting tool consists of a respective metallic wire member, termed a "wire" . The cutting wires are formed into a closed loop and caused to travel between a drive pulley and a respective driven pulley, whose axes are both horizontal. The cutting wires are kept separated from each other by guide rollers, whose axes are also horizontal, in such a way that each cutting wire is in a respective vertical plane, essentially parallel to the planes in which the other cutting wires lie. This arrangement determines the reciprocal distance of the adjacent cutting wires and, consequently, the thickness of the cut slices .

In such machine, the driven pulley is fitted on a cutting head which is vertically mobile with respect to a column supporting structure, between a raised position at the beginning of the cutting stroke and a lowered position at the end of the cutting stroke. A supporting structure, for example a gantry structure, is erected in front of the machine at a distance from the supporting columns and carries a plurality of driven pulleys (one pulley for each cutting wire) . Two guide rollers in the cutting head hold a section of the lower branch of each cutting wire which is arranged in an essentially horizontal position in correspondence of the underlying block to be cut, so that said horizontal section of the lower branch of each wire makes the respective cut in the stone block progressively as the cutting head moves downwards, while the cutting wires are circulated until the cut is completed.

It is noted that in this machine the cutting tool (wire) is advanced in the block to be cut which is held stationary. The blocks are cut by a horizontal branch (or part of a branch) of each cutting wire. The respective distance between the rollers which guide the branch (or part of the branch) of the cutting wire are relatively very high, to permit cutting the block in the direction of width (this dimension is always larger than the height of the block) .

As appears in the description above, the blocks of stone cannot be divided into slides continuously using the machines of the specified known type.

This is because, at the end of each cutting operation, the cutting head must be returned to the raised starting position to be able to resume work after removing the cut slices and positioning a new block to be cut under the cutting head. Furthermore, the quality of the cut made by the wire cutting tools is poor because the horizontal branch of the tools is caused to travel between guide rollers arranged at a relatively high reciprocal distance to permit cutting in the direction of the block width. This causes errors of planarity concerning each cut and parallelism between cuts in the same block using several cutting tools . Particularly, in the middle of the block to be cut, where the cutting operation is most difficult, wire tools apply reduced specific pressure and consequently the cutting efficiency is lower. This causes a relatively high wear which reduces the life of the cutting wires. This invention intends to overcome these shortcomings starting from this notion.

Consequently, the main objective of the invention is to provide a method for dividing blocks of stone into slices by means of one or more cutting members, which can work continuously on a plurality of subsequent blocks to be divided into slices.

Another object of the invention is to provide a method as specified in which the cutting tools can make their respective cuts in the block to be divided in optimal conditions, so to improve planarity of each cut and parallelism of cuts in the same block when several cutting tools are used.

Another object is to provide a method as indicated for increasing the specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving cutting efficiency and reducing wear.

An additional object of the invention is to provide a system for dividing blocks of stone into slices using one or more cutting tools for implementing the method specified above in which it is possible: to continuously cut plurality of blocks of stone to be sequentially divided into slices;

- to use each tool to make the respective cut in the block to be divided in optimal conditions, so to improve planarity of each cut and parallelism of the cuts made in the same block when several cutting tools are used;

- to increase the specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving the cutting efficiency and reducing tool wear .

In order to achieve these objects, the invention provides a method for dividing blocks of stone into slices using one or more cutting tools, whose essential characteristic is described in claim 1. The invention also provides a system for dividing blocks of stone into slices using one or more cutting tools for implementing the aforesaid method, whose essential characteristic is described in claim 5.

Additional advantageous characteristics are illustrated in the accompanying claims.

The above mentioned claims are to be regarded as being reproduced in full here.

In the method according to the invention, each block of stone, belonging to a plurality of blocks of stone arranged in sequence, is advanced along a line of conveyor means, is fed to a cutting station in which at least a closed loop wire cutting tool, which is continuously caused to travel on an essentially vertical plane between a drive pulley and at least a driven pulley, cuts the block with an essentially vertical branch, i.e. in the direction of height of the block, while the block is caused to advance continuously towards a following unloading station.

Preferably, a plurality of closed loop cutting wire tools are working in said cutting station and are caused to travel continuously between said pulleys and are held reciprocally distanced on respective essentially vertical and parallel planes.

In this way, a plurality of blocks of stone fed in sequence and on a line of said conveyor means can be divided into slices continuously.

Furthermore, since the vertical branch of each cutting wire is used to cut the block in the direction of its height

(which is always considerably smaller than the block's width) , the length of the cutting tool is reduced, whereby cuts are always optimal. This improves the planarity of each cut and the parallelism between cuts made in the same block when using several cutting tools. This also increases the specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving cutting efficiency and reducing tool wear. These and other characteristics and advantages of the invention will be more particularly described in the following detailed description with reference to the appended drawings, provided only by way of example, in which: figure 1 is a schematic laterally elevated view of a example of embodiment of the system for dividing blocks of stone material using several cutting members implementing the method according to the invention; - figure 2 is a top plan view (in which some of the blocks being cut, illustrated in figure 1, have been omitted for the sake of simplicity) ; figure 3 is a partial detailed cross-sectional view on a larger scale according to line A-A in figure 1; - figure 4 is a partial detailed cross-sectional view on a larger scale according to line B-B in figure 1;

With reference to the drawings, reference I (figures 1 and 2) indicates as a whole the system for dividing stone blocks into slices according to an embodiment of the invention, while references Bl, B2, B3, B4 indicate respectively four blocks of stone being cut, in following stations of said system. These blocks are preferably squared in the form of parallelepipeds, at least partially, before being cut in the system I. According to the invention, said system I comprises a plurality of following stations, in which respective conveyor means are arranged reciprocally in line and reciprocally form an ideal plane, essentially horizontal, to feed the blocks B1-B4, which are advanced continuously, in sequence and in a straight direction (arrow F, figure 1) , through the stations.

More precisely, said system I comprises the following in the direction of advancement F of each block of stone to be cut: - a first station II for loading, aligning and advancing a block of stone Bl to be divided into slices. Said station II comprises:

• driven roller means 11 for advancing the blocks to be cut according to said direction F; • a fork loading device 12 arranged by the side of the conveyor means 11 and equipped with hydraulic means 12.1 for lifting and lowering the fork 12.2; the fork crosses said roller conveyor means 11 in said movement and handles the block Bl transversally with respect to the conveyors means, so to receive the block Bl (off line and in lowered position) , lifts and moves the block Bl in line and over the conveyor means 11, arranges the block Bl on said conveyor means, when lowers, and retracts off line back to the starting position;

• reference and alignment means 13, arranged on the opposite side of the conveyor means 11; said reference and alignment means comprise a vertical resting plate 13.1 whose surface facing said loading device is parallel with respect to the direction of advancement F, said plate being selectively controlled and moved in the transversal direction with respect to the conveyor means 11 by a hydraulic cylinder 13.2 whose axis is essentially horizontal and orthogonal to the direction F (said means 13 are used to align approximately the block Bl against the surface of the resting plate in the direction of advancement F) ;

• it is to be noted that said roller conveyor means 11 feed the block Bl at a relatively high speed, to the following station, in which block B2 is shown and which is : a transit station 12 comprising an idle roller conveyor 14 on which the feeding speed of the block B2 in the direction F is decelerated. Preferably, the last two rollers are driven and caused to rotate to increase the feeding speed to the block B2 being let off the station 12 and handed over to the next station, i.e.: - an advancement and positioning station 13 where block B3 is shown and comprising:

• driven slat conveyor means 15 which advance the block B3 at a relatively slow speed according to said direction F; • a pair of reference and alignment means 22, reciprocally opposite, one on each side of the conveyor means 15; the structure and function of each means is identical to that of the reference and alignment means 13 described above and ensure that the block B3 is correctly positioned between them before the cutting operation is carried out in the station that follows, i.e.: an advancement and cutting station 14, where block B4 is shown while it is being divided into a plurality of slices and which comprises:

• driven roller conveyor means 16 which advance the block B4 to and beyond the cutting means 17 (which are described below) in said direction F at the same speed as the block B3 on the slat conveyor means 15 (note that during the cut, each block is driven - for the most part of its length - simultaneously by said slat conveyor means 15 and at least the first roller of said conveyor means 16) ;

• cutting means 17 for dividing the block of stone B4 into a plurality of slices using cutting tools T

(approximately eighty in the embodiment shown) and in which each cutting tool consists of a respective metallic wire cutting member, termed a "wire", as described in the aforementioned Italian patent 1,281,035. Particularly, according to the invention, each cutting wire T presents a vertical branch Tl

(figure 1) , freely caused to travel between a pair of rollers of the conveyor means 16 and pulled between a drive pulley 17.1 and a driven pulley

17.2, whose axes are in the same plane, which is essentially vertical and orthogonal to the direction

F, and by the said branch Tl each wire cuts through the block B4 as it advances through the station 14. Reference numeral 17.3 indicates an idle pulley for guiding the cutting wires T, while reference number

17.4 indicates a group of driven pulleys of the wires (one for each wire), as described in the quoted Italian patent 1,281,035. Reference M indicates a gear motor unit which turns the driven pulley 17.1.

Note that the arrangement of the cutting wires T having the vertical cutting branch Tl not only allows cutting the blocks continuously, while the blocks are made to advance on the conveyor means of the station 14, but also shortens the length of the branch, optimising it according to the maximum height of the blocks to be cut in the system I and consequently adjusting the distance between the axis of the drive pulley 17.1 and the axis of the driven pulley 17.2 Figure 3 schematically illustrates the block B4 while it is being divided into a plurality of slices by means of said vertical branches Tl of the cutting wires T.

Furthermore, in said station 14, immediately downstream with respect to said vertical branches Tl, a device 18 is arranged to apply a liquid or molten quick setting adhesive substance (e.g. molten polystyrene foam) . Said applicator 18

(figure 4) comprises means 18.1 for dispensing an adhesive substance by means of a spray nozzle 18.2 carried (over the block B4 being cut) by the end of an essentially horizontal branch of a supporting arm 18.3, whose other arm is essentially vertical and arranged externally with respect to a side of the conveyor means 16 and which are moved transversally with respect to the direction F, while the adhesive substance is applied by the dispensing means. By means of said arrangement, said arm 18.3 is, for example, moved continuously or in intervals, repeatedly, transversally with respect to the direction F.

Figure 4 illustrates the adhesive substance applied on the block B4 being cut. The adhesive substance forms a bead C of adhesive sticking to the upper part of the block and partially introduced on the top of the empty seats V made by the cutting wires T in the block B4, in the form of spacers D. These spacers D separate the slices progressively as they are made in the block B4, compensating at the top of the seats V the thickness of the material removed by the cutting tools T.

In this way, having completed the operation of dividing the block B4 into slices, a "package" B5 of vertical, reciprocally parallel slices is obtained, the slices being arranged side by side and being stabily distanced by means of the spacers D. The package B5 consequently reaches the following station, which is the last in the system I, i.e.: an unloading station 15 comprising:

• driven roller conveyor means 19 for advancing the package B5 at a relative high speed and

• a fork unloading device 20, arranged externally by the side of said conveyor means 19 and whose arrangement and structure is essentially that of the loading device 12, but whose function is reversed. In the unloading device 20, the prongs of the fork take the package B5 lifting it from the conveyor means (19) and translate it transversally with respect to the direction F, over the opposite side of the conveyor means, whereby arranging it on extraction conveyor means 21 which remove it from the line and send it to the following processes. Of course in practice numerous variants may be applied to what has been described and illustrated purely by way of a non-restrictive example without thereby going beyond the scope of the invention and therefore the protection of this industrial monopoly.

For example, also one only wire cutting tool can work in the advancement and cutting station. Mechanical jacks can be used instead of hydraulic cylinders, for example.

Claims

1. Method for dividing blocks of stone into slices using one or more wire cutting tools, termed "cutting wires", formed into a closed loop and caused to travel between a drive pulley and at least one driven pulley, whose axes are both horizontal, characterised in that each block of stone belonging to a plurality of blocks of stone arranged in sequence is advanced along a line of conveyor means which feed it to an advancement and cutting station, in which at least a closed loop cutting wire tool - caused to travel continuously in a plane which is essentially vertical between a drive pulley and at least a driven pulley - makes a corresponding cut in said block with a branch (a part of a branch, respectively) , the cut being essentially vertical, i.e. in the direction of the height of the block, while the block is advanced continuously towards a following unloading station, so that all the blocks belonging to a plurality of blocks of stone fed in sequence and in line along said conveyor means are divided into slices; this method permitting continuous operation in optimal conditions in terms of planarity of each cut and parallelism between several cuts in a same block, when working with several cutting tools, with high specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving cutting efficiency and reducing tool wear.

2. Method according to claim 1, characterised in that each block of stone in said advancement and cutting station is divided into slices by a plurality of closed loop cutting wire tools caused to continuously travel between said drive pulley and said driven pulley and which are reciprocally distanced and arranged in respective planes essentially vertical and parallel by means of horizontal axis guiding rollers, in such a way that each cutting wire is in a respective vertical plane, essentially parallel to the planes in which the other cutting wires lie.

3. Method according to claim 1 or 2, characterised in that the blocks of stone to be cut into slices are continuously advanced in sequence and in a straight direction (arrows F, figure 1) through a plurality of following stations, comprising said advancement and cutting station and in which respective conveyor means are arranging reciprocally in line and form an ideal plane which is essentially horizontal for feeding the blocks of stone.

4. Method according to claim 3, characterised in that said blocks are advanced in sequence through: a loading, aligning and advancement station (II) , at a relatively high speed; a transit station (12) in which the feeding speed according to the direction of advancement (F) is decelerated and then accelerated, when it is output from the station; an advancement and position station (13) and an advancement and cutting station (14) in which the speed is kept relatively slow and essentially constant, and an unloading station (15) in which a "package" of slices cut from each block is sequentially received, the block being advanced at a speed which is relatively high to an unloading device (20, 21) which removes it from the line.

5. System for dividing blocks of stone into slices using one or more wire cutting tools, termed "cutting wires", formed into a closed loop and caused to travel between a drive pulley and at least one driven pulley, whose axes are both horizontal, for implementing the method according to one or more of the claims from 1 to 4, characterised in that it comprises an advancement and cutting station (14), in which each block of stone belonging to a plurality of blocks (B1-B4) of stone arranged in sequence is advanced along a line of conveyor means (16) which fed it to at least a closed loop cutting wire tool

(17) - caused to travel continuously in a plane which is essentially vertical between a drive pulley (17.1) and at least one driven pulley (17.2) - making a corresponding cut in said block with a branch (a part of a branch, respectively), the cut being essentially vertical (Tl) , i.e. in the direction of the height of the block, while the block is advanced continuously towards a following unloading station (15), so that all the blocks belonging to a plurality of blocks of stone fed in sequence and in line along said conveyor means are divided into slices; this arrangement permitting continuous operation in optimal conditions in terms of planarity of each cut and parallelism between several cuts in a same block, when working with several cutting tools, with high specific pressure of each cutting tool, particularly in the middle of the block to be cut, whereby improving cutting efficiency and reducing tool wear.

6. System according to claim 5, characterised in that in said advancement and cutting station (14) each block of stone is divided into slices by a plurality of closed loop wire cutting tools (17) caused to continuously travel between said drive pulley (17.1) and said driven pulley (17.2) and which are reciprocally distanced and arranged in respective planes essentially vertical and parallel by means of horizontal axis guiding rollers (17.3), in such a way that each cutting wire is in a respective vertical plane, essentially parallel to the planes in which the other cutting wires lie.

7. System according to claim 5 and/or 6, characterised in that it comprises a plurality of following stations (II- 15), comprising said advancement and cutting station (14) and in which respective conveyor means (11, 14, 15, 16, 19) are arranged reciprocally in line and form an ideal plane which is essentially horizontal for feeding the blocks of stone to be cut, the blocks of stone being advanced continuously, in sequence, in a straight direction (arrows F, figure 1) through the stations.

8. System according to claim 7, characterised in that it comprises in sequence along the direction of advancement (F) of the blocks upstream with respect to this advancement and cutting station (14): - a block loading, aligning and advancement station

⁽ID; a transit station (12), and a block advancement and position station (13) .

9. System according to claim 8, characterised in that said block loading, aligning and advancement station (II) comprises: driven roller means (11) for advancing the blocks to be cut according to said direction (F) ; a fork loading device (12) arranged by the side of the conveyor means (11) and equipped with means (12.1) for lifting and lowering the fork (12.2); the fork crosses said roller conveyor means (11) in said movement and handles the block (Bl) transversally with respect to the conveyors means, so to receive the block (Bl) (off line and in lowered position) , lifts and moves the block (Bl) in line and over the conveyor means (11) , arranges the block (Bl) on said conveyor means, when lowers, and retracts off line back to the starting position; reference and alignment means (13), arranged on the opposite side of the conveyor means (11); said reference and alignment means comprise a vertical resting plate (13.1) whose surface facing said loading device (12) is parallel with respect to the direction of advancement (F) , said plate being selectively controlled and moved in the transversal direction with respect to the conveyor means (11) by a cylinder or jack (13.2) whose axis is essentially horizontal and orthogonal to the direction (F) and which is used to align the block (Bl) against said surface at least approximately in the direction of advancement (F) .

10. System according to claims 8 and 9, characterised in that said roller conveyor means (11) feed the block (Bl) to the following station at a relatively high speed.

11. System according to claims 8 and 9, characterised in that said transit station (12) comprises an idle roller conveyor (14), on which the feeding speed of the block (B2) in the direction (F) is decelerated; the last two rollers are driven and caused to rotate to increase the feeding speed to the block (B2) being let off the station according to which feeding speed the block is handed over to the following station.

12. System according to at least one of the claims 8 to

11, characterised in that said advancement and positioning station (13) comprises:

- driven slat conveyor means (15) which advance the block (B3) at a relatively slow speed according to said direction of advancement (F) ; a pair of reference and alignment means (22), reciprocally opposite, one on each side of the conveyor means (15) ; - the structure and function of each means is identical to that of the reference and alignment means (13) in the loading station (II) - which ensure that the block

(B3) is correctly positioned between them before the cutting operation which is carried out in the advancement and cutting station (14) that immediately follows.

13. System according to one or more of the claims 5 to

12, characterised in that said advancement and cutting station (14) comprises: driven roller conveyor means (16) which advance a block (B4) being cut to and beyond said at least one closed loop wire cutting tool (17) in said advancement direction (F) at the same speed as the block (B3) immediately preceding on the slat conveyor means (15) so that during the cut, each block is driven - for the most part of its length - simultaneously by said slat conveyor means (15) and at least the first roller of said conveyor means (16) and said at least a closed loop wire cutting tool (17) arranged with a vertical branch (Tl) , freely caused to travel between a pair of rollers of the conveyor means (16) and pulled between a drive pulley (17.1) and a driven pulley (17.2), whose axes are in the same plane, which is essentially vertical and orthogonal to the advancement direction (F) , so that said wires by said branch (Tl) cut through the block (B4) as it advances through the station (14) .

14. System according to claim 13, characterised in that it comprises a plurality of closed loop cutting wire tools (17) arranged with a vertical branch (Tl) freely passing between a pair of rollers of said conveyor means (16) and pulled between a drive pulley (17.1) and at least a driven pulley (17.2) .

15. System according to claim 13 or 14, characterised in the said station (14), downstream to said vertical branch (Tl) of the tool, respectively of the wire cutting tools (17) , is provided a device (iδ) for applying a liquid or molten quick ^■ setting adhesive substance (e.g. molten polystyrene foam), which comprises means (18.1) for dispensing an adhesive substance by means of a spray nozzle (18.2) carried - over the block (B4) being cut - by the end of a branch of a supporting arm (18.3), whose other arm is supported by sliding means arranged externally with respect to a side of the conveyor means (16), and which are moved essentially transversally with respect to the direction (F) , while the adhesive substance is applied by the dispensing means, so that the adhesive substance is applied on the block (B4) being cut and forms a bead of adhesive (C) sticking to the top of the block and partially introduced on the top of each empty seat (V) made by the cutting tool (17) in the block (B4) in the form of a spacer (D) ; the adhesive separates the slices progressively as they are divided from the block (B4) and compensates for the thickness of the material being removed by the respective cutting tool at the top of each seat (V) , whereby obtaining at the end of the cutting operation of each block (B1-B4), a "package" (B5) of slices arranged vertically side by side and reciprocally parallel, which are held stably distanced by means of a plurality of said spacers (D) .

16. System according one or more of the claims 5 to 15, characterised in that an unloading station (15) is arranged downstream to said advancement and cutting station (14) and comprises: driven roller conveyor means (19) for receiving and advancing a "package" of cut slices (B5) at a relative high speed and a fork unloading device (20), arranged externally by the side of said conveyor means (19) , whose prongs take the package (B5) lifting it from the conveyor means (19) and translate it transversally with respect to the direction of advancement (F) , over the opposite side of the said conveyor means, whereby arranging it on extraction conveyor means (21) which remove it from the line and send it to the following processes.