WO1999055506A1

WO1999055506A1 - Stone cutting apparatus using a saw wire carrying chain like cutting elements

Info

Publication number: WO1999055506A1
Application number: PCT/IT1999/000104
Authority: WO
Inventors: Umberto Ferri
Original assignee: Umberto Ferri
Priority date: 1998-04-24
Filing date: 1999-04-23
Publication date: 1999-11-04
Also published as: AU3533299A

Abstract

An apparatus for cutting blocks of stone materials by means of a cutting wire (1) provided with teeth (2) having cutting edges or plates (3) made of sintered abrasive material. The teeth (2) are provided with coupling members (4) able to engage a pair of opposite gear wheels or pulleys (5), one of which is driven while the other is idle. The projecting coupling member (4) is capable of engagement between the teeth of the gear wheels or pulleys (5) which are further provided with side guide members (6) so that the wire always remains in the correct engaging position. The cutting teeth (2) have an opening for receiving the carrier wire (1) which opening is closed by a closing plate (7) to which the cutting edge or plate (3) of sintered material is welded.

Description

STONE CUTTING APPARATUS USING A SAW WIRE CARRYING CHAIN LIKE CUTTING ELEMENTS

The present invention relates to the cutting of marble, granite and generally stone materials, and particularly an apparatus that uses a serrated wire provided with diamond cutting points. Reciprocating diamond cutting frames are currently used to make a plurality of cuts m a block of stone material at the same time.

One drawbacks of such apparatus is the great noise due above all to the cutting method using long cutting blades which propagate the noise generated by their friction during the cutting step.

A second drawback of such apparatus is that it is unable to work on a continuous basis . Each block has to be positioned and held m its position ready to be cut and then removed after the cut.

Instead of using blades, diamond tooth disc machines have been proposed that, however, facilitate the propagation of noise so as to reach quickly an acoustic pollution such as to exceed the threshold allowed by law.

Diamond wire machines based on the friction between wire and stone material are also known.

One drawback of the diamond wire apparatus is that the diamond portions of the wire deposited by electrolysis are easily worn out and then the cutting capability is deteriorated m a short time. Still a drawback of such diamond wires is that they need driving wheels or pulleys of large diameter, the transmission being provided by the friction between the wire and the races of the pulleys. This means that in case of slipping between wire and pulley the contact surfaces wear out quickly and need to be restored with the result of increasing the cost and decreasing the productivity.

The present invention seeks to overcome the problems of the prior art by providing an apparatus equipped with one or more diamond tooth wires guided or not and capable of reducing the propagation of noise and to keep the cutting capability unchanged for long time. A second object of the invention is to provide an apparatus, which allows cuts of essentially reduced width to be carried out, thus reducing also the waste of material.

A third object of the invention is to provide an apparatus having a diamond tooth wire in which the teeth are made of a wearproof sintered material.

Still another object of the invention is to provide an apparatus of the above-mentioned type capable of operating on a continuous basis in combination with belt conveyers of the known type which move the blocks before, during, and after the cutting operation.

A better understanding of the invention will ensue from the following detailed description with reference to the annexed drawings, which schematically show some preferred embodiments by way of a not limiting example .

In the drawings :

Figure 1 is a cross section of a tooth of the wire according to a first embodiment of the invention;

Figure 2 like Figure 1 shows a second embodiment of a tooth located m the driving gearwheel;

Figures 3 and 4 show two embodiments of the member connecting the tooth to the gearwheel as well as the surface of connection to the wire;

Figure 5 shows a wire according to the invention;

Figure 6 is a detail of a tooth of the wire of Fig. 5;

Figure 7 schematically shows the wire assembled on the driving wheels;

Figures 8 and 9 like Figure 7 show a guide only for the teeth of the cutting side and a guide for both sides of the wire, respectively;

Figures 10 and 11 schematically show two possible applications of the invention for the transversal or longitudinal vertical cut of the blocks of stone materials;

Figure 12 is a cross section of a tooth connected to the driving wire;

Figure 13 shows a "U" or "C" channel to which the cutting edge is welded;

Figure 14 is a cross section of a driving wire;

Figure 15 shows the plate for closing and tightening the "ϋ" or "C" channel of Figure 12;

Figure 16 shows a different type of solid section supporting the cutting edge;

Figure 17 schematically shows the interposition of spacers between the teeth connected to the driving wire;

Figure 18 shows a further type of a solid circular section supporting the cutting edge.

With reference to Figures 1 to 11 the cutting apparatus according to the invention includes a frame provided with at least a pair of opposite gear wheels or pulleys 5, one of which is a driving wheel the other is idle, both wheels being able to engage the diamond teeth 2 of a stretched wire 1.

More particularly, the described diamond tooth wire consists of a wire 1 preferably of steel having a square cross section to which teeth 2 are rigidly connected so that each of them is provided with a blade or cutting edge 3 of sintered abrasive material directed outwards and, on the opposite side, with a coupling member 4 capable of engagement between the teeth of the gear wheels or pulleys 5 and the side guide members 6 of the latter so that the wire always remains m the correct engaging position with respect to the gear wheels without projecting outwards. In a first embodiment shown m Figure 1, each tooth 2 has a "ϋ"-shaped section supporting said projecting coupling member 4 m which wire 1 is passed and secured.

After tooth 2 is secured to wire 1 by braze welding, the open side of the "U"-shaped section s closed by a plate or metal foil 7 to which plate or cutting edge 3 of sintered abrasive material is welded.

Alternatively, plate 3 can be secured without interposition of plate 7. Of course, the distance between subsequent teeth 2 is equal to the pitch of the toothing of gear wheel 5. Accordingly, the length of the wire is a multiple of the pitch of the gear wheel .

The serrated wire according to the invention can be assembled as follows: the wire is placed m the "U"- shaped section provided with projecting member 4, a foil of welding material is put between said "U"- shaped section and wire 1, a second foil of welding material, a metal plate 7 (optional) and a further foil of welding material are placed on the wire, and eventually a sintered diamond tooth 3 is placed thereon. At this point the whole assembly needs only to be heated to cause all of the components of tooth 2 to be welded to wire 1. The next teeth are then welded to complete the wire, which can be made in one piece or a piece after the other.

Of course, the width of the cutting edge or sintered plate 3 has to be slightly larger than that of the "U"-shaped section and wire 1. An easy way of determining the correct position of tooth 2 to be secured to wire 1 is to use a gear wheel similar to those used to move and to stretch the wire in use. In this way, the projecting member 4 of each tooth 2 is put into a suitable cavity formed in the toothing of the wheel at the correct distance from the preceding tooth.

Advantageously, the use of the serrated wire allows the diameter of driving and stretching wheels 5 to be strongly reduced. In fact, the driving force is not any longer proportional to the friction between wire 1 and wheel 5 (and the contact surface and the tension between them either) . This allows cutting apparatus having size generally lower than those of the prior art as well as having minor problems of tensioning the wires and breaking the same because of slipping to be more easily manufactured.

It is then possible to use gear wheels with diameters of the order of 20-30 cm or more avoiding at the same time the need of having a high wire tension because of the pulling of wire 1. With particular reference to Figures 2 and 3, it should be appreciated that a second simplified embodiment may be provided in which tooth 2 is formed by a "T"-shaped section whose vertical arm is the projecting member 4 for the coupling to gear wheel or pulley 5, and the horizontal arm forms the surface to be directly connected to the square section wire, sintered plate 3 being directly welded to wire 1 at the opposite side with respect to the "T"-shaped section. It should be noted, as shown in Figure 4, that coupling member 4 of each tooth 2 can advantageously have such a width as to allow cable 1 to be secured thereto. Thus, the manufacturing of the serrated wire can be made easier. A third embodiment of the invention provides a guide 8 located between the two wheels 5 and laying on the plane of wire 1 so as to guide teeth 2 on the wire side contacting the material to be cut and, if necessary, also those on the opposite wire side (see Figure 9) .

Such an arrangement is particularly important if the faces of the blocks of stone materials to be cut are not even and/or parallel to the direction of the serrated wire. The surfaces of teeth 2 in contact with guide 8 may also be coated with an antifriction material in order to reduce the friction between guide and projecting members 4 put therein. The problems of the wear by friction can also be overcome by coating the contact surface with wearproof products based on cobalt, ceramics, etc.

In a simplified embodiment, the guide of teeth 2 is only applied to that side of the wire which is cutting the material, as shown in Figure 8 by numeral 8A. Advantageously, although it is preferable to use a square section wire 1, a wire 1 of any section, e.g. a circular section, can be used without any problem by putting and welding it to the "U"-shaped section. The invention has several applications in machines of different types for cutting blocks of stone material.

In particular, Figures 10 and 11 show two types of cutting machines having essentially known arrangements, one for the transversal vertical cut, one for the longitudinal vertical cut on a "continuous" basis. In the first case serrated wire 1 moves downwards when the block is being cut, while in the second case the wire does not move and the block to be cut is shifted with respect to the wire as the cut proceeds . Finally, in both above-mentioned applications two or more parallel wires can be advantageously provided so that several cuts may be executed at the same time. Thus, the productivity and the raw material machining rate are considerably increased. With regard to guides 8 and 8A used, if necessary, for improving the alignment of the teeth during the cut, as already mentioned, it should be appreciated that they often reach such a length as to make them extremely flexible, even if they are rigid, with the result that their duty could not be satisfactorily performed. For such reason, they are usually placed under longitudinal traction by ordinary end tie rods (not shown) .

A further embodiment of the invention shown in Figures 12 to 18 provides that teeth 2 are secured to driving wire 1 by mechanical means without using braze welding as in the former applications. In fact, each tooth is first secured in this case to the driving wire by braze welding of a cutting abrasive member 3 to the side of the "U"-shaped (or "C"-shaped) section which is opposite to the side where coupling member 4 and driving wheel are arranged.

Next, said section is radially applied to driving wire 1 and a locking plate 7A, thus ensuring a mechanical fastening closes its open side.

According to a peculiar feature of such further embodiment of the invention, the inside wall of said section, which is opposite to the open side, and the closing plate 7A are provided with a toothing 11 that pierces crosswise wire 1 so that the relative movements of wire 1 and tooth 2 are avoided. Advantageously, said plate may be secured to the section by a snap coupling means, by pressure or by screws . In the described embodiment there is also provided tongue means, preferably in the form of pins 13, which are orthogonal to the side of the section opposite to plate 7A and able to be coupled to such plate so that the latter can be secured just by pressing it in its position. 10

It should be noted that in the disclosed embodiment brazing 12 is used just for welding the cutting abrasive edge 3 to the section before fastening the tooth to the wire. With regard to the foregoing the tooth should be secured to the wire according to the following method: 1. securing cutting abrasive member 3 to the side of the "U"-shaped or "C"-shaped section which is opposite to tooth 4; 2. radially placing the "U"-shaped or "C"-shaped section on wire 1;

3. closing and locking the "U"-shaped or "C"-shaped section by a plate 7A able to be fastened by snap coupling means, by pressure or by screws. It should be appreciated that in disclosed embodiment the "U"-shaped or "C"-shaped section is essentially squared, however, in case driving wire 1 is circular, also the above-mentioned section will have a rounded profile capable of mating the wire when it is secured thereto.

According to another embodiment of the invention, Figure 16 shows a different section for supporting cutting edge 3 which is closed so that driving wire 1 has to be threaded and secured thereto. In this case cutting edge 3 can be electrodeposited or brazed on the section itself.

Finally, spacers 10 (Fig. 17) placed between teeth 2 secured to the wire can be provided for distributing the shearing stress to all teeth. With particular reference to Figure 18, a further 11

embodiment of the invention has a section for supporting cutting edge 3 which is closed and essentially circular. In this case, the cutting edge and the tooth have preferably concave contact surfaces which are conjugated to the surface of the supporting section so as to facilitate the fastening of the several portions to such supporting section. The present invention has been described and illustrated according to preferred embodiments thereof, however, it should be understood that those skilled in the art can make equivalent modifications and/or replacements without departing from the scope of the present industrial invention.

Claims

12 Claims

1. An apparatus for cutting blocks and/or lumps of stone materials, characterized in that a wire (1) provided with teeth (2) is used as cutting tool, said teeth being provided with coupling members (4) able to engage suitable gear wheels (5) , said teeth (2) being provided with cutting edges or plates (3) made of sintered abrasive material.

2. The cutting apparatus of claim 1, characterized in that it comprises a frame provided with at least a pair of opposite gear wheels or pulleys (5) , one of which is a driving wheel the other is idle, both wheels being able to engage the diamond teeth (2) of the stretched wire (1) , said diamond tooth wire consisting of a wire (1) to which teeth (2) provided with a blade or cutting edge (3) of sintered abrasive material directed outwards are rigidly connected on one side, and on the opposite side there is provided a projecting coupling member (4) capable of engagement between the teeth of the gear wheels or pulleys (5) which are further provided with side guide members (6) so that the wire always remains in the correct engaging position with respect to the gear wheels without projecting outwards.

3. The cutting apparatus of the preceding claims, characterized in that the distance between subsequent teeth (2) is equal to the pitch of the toothing of 13

gear wheel (5) , the length of the wire being a multiple of the pitch of the gear wheel (5) .

4. The cutting apparatus of the preceding claims, characterized in that, as the driving force is transmitted by the engagement of the projecting members (4) of teeth (2) with gear wheels (5), the diameter of such wheels is strongly reduced, thus allowing cutting apparatus having size generally lower than those of the prior art to be manufactured, and the tension of wire (1) is limited.

5. The cutting apparatus of the preceding claims, characterized in that each tooth (2) has a "U"-shaped section supporting said projecting coupling member (4) in which wire (1) is passed and secured by braze welding, the open side of the "U"-shaped section being closed by a plate or metal foil (7) to which plate or cutting edge (3) of sintered abrasive material is welded.

6. The cutting apparatus of the preceding claims, characterized in that the sintered abrasive plate (3) is directly connected to wire (1) , said wire having a square section.

7. The cutting apparatus of the preceding claims, characterized in that the width of the cutting edge or sintered plate (3) is slightly larger than that of the "U"-shaped section and wire (1). 14

8. The cutting apparatus of the preceding claims, characterized in that instead of the "U"-shaped section of tooth (2) there is provided a "T"-shaped section whose vertical arm is the projecting member (4) for the coupling to gear wheel or pulley (5), and the horizontal arm forms the surface to be directly connected to the square section wire, sintered plate (3) being directly welded to wire (1) at the opposite side with respect to the "T"-shaped section.

9. The cutting apparatus of claim 8, characterized in that in alternative to the "T"-shaped section coupling member (4) of each tooth (2) can advantageously have such a width as to allow cable (1) to be secured thereto.

10. The cutting apparatus of claims 1 to 4, characterized in that each tooth (2) consist of a "U"- shaped or "C"-shaped section able to be secured to driving wire (1) only by mechanical means, an abrasive cutting member (3) being previously welded by brazing (12) to said section.

11. The cutting apparatus of claim 10, characterized in that the inside wall of said "U"-shaped or "C"- shaped section is opposite to the open side and is provided with a toothing (11) able to pierce crosswise wire (1) so that the relative movements of wire (1) and said section are avoided. 15

12. The cutting apparatus of claim 11, characterized in that the open side of "U"-shaped or "C"-shaped section engaged with wire (1) is closed by a closing plate (7A) whose inner side is provided with a toothing (11) so that the relative movements of wire (1) and said section are avoided.

13. The cutting apparatus of claims 10 to 12, characterized in that there are provided abrasive cutting edges (3) that are secured to driving wire (1) according to the following steps :

- welding by brazing abrasive cutting member (3) to the side of the "U"-shaped or "C"-shaped section which is opposite to the side of the coupling member (4) engaged to the driving wheel;

2. placing said section on driving wire (1);

3. closing and locking said section to wire (1) by a plate (7A) provided with snap coupling means (13) , pressure coupling means or screws.

14. The cutting apparatus of claims 10 to 13, characterized in that said fastening means of plate (7A) are pins (13) which are orthogonal to the side of the section opposite to plate (7A) and able to be coupled to such plate so that the latter can be secured just by pressing it in its position.

15. The cutting apparatus of claim 10, characterized in that as an alternative to "U"-shaped or "C"-shaped section each tooth (2) has a hollow section supporting 16

cutting edge (3) so that driving wire 1 has to be threaded and secured thereto.

16. The cutting apparatus of claims 10 to 15, characterized in that spacers (10) are placed between teeth (2) for distributing the shearing stress to all teeth.

17. The cutting apparatus of claim 16, characterized in that said section for supporting cutting edge (3) is closed and essentially circular.

18. The cutting apparatus of the preceding claims, characterized in that a guide (8A) located between the two wheels (5) and laying on the plane of wire (1) is provided so as to guide projecting coupling members

(4) of teeth (2) on the wire side contacting the material to be cut.

19. The cutting apparatus of the preceding claims, characterized in that there is provided a guide (8) that also keeps in the correct position those teeth (2) which are on the opposite side with respect to the cutting side.

20. The cutting apparatus of the preceding claims, characterized in that the surfaces of teeth (2) in contact with guide (8, 8A) are coated with an antifriction material in order to reduce the friction between guide (8, 8A) and projecting members (4) put 17

therein.

21. The cutting apparatus of the preceding claims, characterized in that, as guides (8, 8A) used for improving the alignment of teeth during the cut often reach such a length as to make them extremely flexible, ordinary end tie rods capable of holding said guide under longitudinal traction increasing the rigidity thereof can be used.

22. The cutting apparatus of the preceding claims, characterized in that the problems of the wear by friction are overcome by coating the contact surface with wearproof products based on cobalt, ceramics, etc.

23. The apparatus for cutting blocks and/or lumps of stone materials of the preceding claims, characterized in that there are provided cutting machines both for the transversal vertical cut in which serrated wire (1) moves downwards when the block is being cut, and the longitudinal vertical cut on a "continuous" basis in which the wire does not move and the block to be cut is shifted with respect to the wire as the cut proceeds .

24. The cutting apparatus of the preceding claims, characterized in that two or more parallel wires (1) can be provided so that several cuts may be executed at the same time.