With particular reference to the ceramics sector, machining centers are known for performing longitudinal and transverse cutting work on slab- like articles, such as ceramic slabs known as Lam'Slab™, in order to obtain quadrangular cladding elements which are smaller than the original slab and are known as "square tiles".

This type of machining center substantially provides a first assembly for the longitudinal cutting of the slab into a plurality of strips and a second assembly for the transverse cutting of such strips to obtain a plurality of square tiles, the two assemblies being arranged in series transversely to the direction of flow of the material along the production line.

Each cutting assembly consists of a beam which can move alternately along the cutting direction and supports a plurality of cutting heads provided with a rotating blade, the arrangement of which along such beam is adjustable depending on the cut to be performed; below the cutting heads there is a worktable for supporting the article being cut and for the advancement thereof once cutting has ended. Such worktable consists of a plurality of motorized belts arranged in a fixed position, which are mutually parallel and spaced, for the movement of the article being worked through the cutting center (from the first cutting assembly to the second cutting assembly or from the second cutting assembly towards the output), between which a plurality of crossmembers for supporting sucker elements are interposed which can move alternately in a vertical direction between a raised position during the cutting step, in which the sucker elements protrude above the belts, picking up the article that previously rested on the belts, and a lowered position during the transfer step, in which the article is kept rested on the belts. During cutting work, the arrangement of the crossmembers and of the cutting heads is such that no interference occurs between the sucker elements aligned along the cutting direction and the rotating blades.

When the format to be cut varies and therefore the position of the cutting heads varies, it is possible to intervene by moving the crossmembers, which must in any case be arranged in the spaces left free by the motorized belts.

This machining center is not free from drawbacks, which include the fact that it allows a discrete adjustment of the dimensions of the format that can be obtained from the cutting of the ceramic slab, impairing considerably the flexibility of the work that can be performed. This adjustment is in fact limited in longitudinal cutting by the spacing with which the sucker elements are distributed on the respective crossmembers and, in transverse cutting, by the fact that the crossmembers can be arranged exclusively in the spaces left free by the motorized belts. Further, these operations for moving the crossmembers must be performed manually, consequently prolonging the machine downtimes when the work to be performed changes.

Moreover, these constraints imposed on the arrangement of the sucker elements with respect to the cutting blades in some cases do not allow support of the article proximately to the blade, leaving the portion of material that is proximate to the cut in a cantilever arrangement, with the consequent risk of obtaining defective cut parts which therefore have to be rejected.

Further, the installation of this type of machining center in a production line entails a misalignment between the flow of material in input to the center and the material in output from it. Taking into account the fact that generally production systems have a flow of material with a linear trend, the installation of this type of machining center in an existing system can entail the need to adapt the arrangement of the stations in which the work is done upstream or downstream of such center. Disclosure of the Invention

The aim of the present invention is to eliminate the drawbacks noted above of known machining centers, by devising a machine for cutting substantially slab-like articles, particularly made of ceramic, stone-like and similar materials, which allows continuous adjustment of the format that can be obtained from the cutting process, optimizing the flexibility of such machine.

Within this aim, an object of the present invention is to automate the positioning of the elements involved as the format to be cut varies, minimizing machine downtimes as the work to be performed changes. Another object of the present invention is to provide adequate support of the part during cutting also at the perimetric regions, so as to reduce the formation of work rejects.

Another object of the present invention is to obtain a flow of material that is linear, providing the entry of the slab and the exit of the square tiles in mutual alignment.

Another object of the present invention is to provide a machine which is simple, relatively easy to provide in practice, safe to use, effective in operation, and has relatively low costs.

This aim and these and other objects which will become better apparent hereinafter are achieved by the present machine for cutting substantially slab-like articles, particularly made of ceramic, stone-like and similar materials, comprising a frame for supporting at least one cutting assembly, which can move alternately along a cutting direction and whose arrangement can vary along a first axis which is substantially transverse to said cutting direction, and at least one assembly for supporting at least one substantially slab-like article, which is adapted to make contact with said article during cutting in at least one region that is not crossed by the cutting direction, characterized in that said supporting assembly is associated with said frame so that it can slide continuously along a second axis which is substantially parallel to said first axis, means for rigid and temporary connection of the supporting assembly to the frame being further provided for repositioning said supporting assembly along the second axis as the position of the cutting assembly along the first axis varies. Brief description of the drawings Further characteristics and advantages of the present invention will become better apparent from the following detailed description of two preferred but not exclusive embodiments of a machine for cutting substantially slab-like articles, particularly made of ceramic, stone-like and similar materials, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a schematic plan view of a first embodiment of a machine according to the invention for the longitudinal cutting of manufactured articles;

Figure 2 is a schematic side view of the machine of Figure 1; Figure 3 is a schematic front view of the machine of Figure 1 ;

Figure 4 is a schematic plan view of a second embodiment of the machine according to the invention for the transverse cutting of articles; Figure 5 is a schematic side view of the machine of Figure 4; Figure 6 is a schematic front view of the machine of Figure 4; Figure 7 is a partially sectional enlarged-scale schematic view of a portion of Figure 6 related to a supporting assembly and to the corresponding transfer assembly. Ways of carrying out the Invention

With reference to the figures, the reference numerals Ia, Ib generally designate a machine for cutting substantially slab-like articles M, particularly made of ceramic, stone-like and similar materials. The expression "slab-like article" is used to refer to a body that has a reduced thickness with respect to the extension of its mutually opposite faces, which are mutually parallel and have a generally rectangular shape. The article M therefore has a substantially elongated shape and is inserted in the machine

1 preferably along its longitudinal orientation.

The machine Ia, Ib is designed particularly but not exclusively to cut articles M of the type of ceramic slabs known as Lam'Slab™ or previously cut portions thereof. The machine Ia, Ib comprises a frame 2 for supporting at least one cutting assembly 3, which can move alternately along a cutting direction T and can assume a variable position along a first axis Al, which is substantially transverse to said cutting direction, and at least one supporting assembly 4 for at least one article M, which is adapted to make contact with such article during cutting in at least one region that is not crossed by the cutting direction T. The supporting assembly 4 is associated with the frame

2 so that it can slide continuously along at least one second axis A2, which is substantially parallel to the first axis Al.

The first axis Al and the second axis A2 are preferably perpendicular to the cutting direction T.

The frame 2 further comprises a carriage 2a, which is arranged in an upper region with respect to the supporting assembly 4 and lies along the first axis Al, with which the cutting assembly 3 is associated so that it can slide. The frame 2 further has two beams 2b for guiding the sliding of the carriage 2a, which are arranged parallel to the cutting direction T and with which the carriage 2a is associated slidingly. The frame 2 might have a single beam 2b that supports the carriage 2a in a cantilever fashion.

The cutting assembly 3 has a cutting element, which in the embodiments shown consists of a rotating blade 5 but the possibility is not excluded to use tools having a different shape or other technologies for cutting the articles.

The cutting assembly 3 is of a conventional type and is therefore not described in detail.

The machine Ia, Ib further has means 6 for rigid and temporary connection of the supporting assembly 4 to the frame 2 for repositioning said assembly along the second axis A2 as the position of the cutting assembly 3 along the first axis Al varies, so as to avoid interference between the rotating blade 5 in operation and the supporting assembly.

The machine Ia, Ib further comprises at least one assembly 7 for transferring the article M from an input region 8 to an output region 9 along an advancement direction A; such assembly is also associated with the frame 2 so that it can slide continuously along the second axis A2 and is jointly connected for sliding with the supporting assembly 4.

The machine Ia, Ib can be provided, at the input region 8 and/or at the output region 9, with a corresponding system for the conveyance of the article M, such as a motorized roller bed.

Advantageously, the machine Ia, Ib can be installed in a production line, which already exists or is newly built, so that the advancement direction A is aligned with the flow of material along said line. Moreover, the machine Ia, Ib is provided with means 10 for temporary disengagement of the connection means 6 and with means 11 for positioning the supporting assembly 4 and the transfer assembly 7 along the second axis A2.

The connection means 6 are of the friction type and have at least one lever 12, which is associated, so as to oscillate, with the supporting assembly 4 between an active configuration, in which it is pressed against the frame 2 so as to block the sliding of the supporting assembly 4 along the second axis A2, and an inactive configuration, in which it is spaced from the frame 2 so as to release the sliding of the supporting assembly 4 along the second axis A2. Finally, the connection means 6 comprise flexible means for retaining and returning the lever 12 to the active configuration, which are adapted to contrast the movement of the lever from the active configuration toward the inactive configuration; such flexible means can consist of a conventional elastic spring, which is not visible in the figures. The disengagement means 10 comprise at least one first element for actuating the movement of the lever 12 from the active configuration to the inactive configuration, which can engage said lever for retention in the inactive configuration in contrast with the action of said flexible means. The first actuator 10 is associated slidingly with a bar 13, which is associated with the frame and is arranged parallel to the second axis A2. The first actuator 10 is of the type of a first hydraulic or pneumatic cylinder, the stem of which engages in a corresponding seat which is associated with the lever 12, not visible in the figures; however, the first actuator 10 might also be of the electric type. The positioning means 11 comprise at least one second actuator, which is supported by the frame 2 for actuation of the first actuator 10, which cooperates with the lever 12 in the inactive configuration, with an alternating translational motion along the second axis A2, entraining the entire supporting assembly 4 and the transfer assembly 7 jointly connected thereto. The second actuator 11 can be of the pneumatic, hydraulic or electric type.

The frame 2 has at least two guiding elements 14, which are arranged parallel to the second axis A2 at the mutually opposite ends of the supporting assembly 4 along the cutting direction T, and along which said supporting assembly is associated slidingly. The connection means 6 further comprise two levers 12, which are associated with the supporting assembly 4, each at one respective guiding element 14; the disengagement means 10 comprise two first actuators, which are supported so that they can slide on corresponding bars 13, each of which actuators cooperates with a respective lever 12, and the positioning means 11 have two second actuators for entraining respective first actuators 10. It is noted that the movement of the two second actuators 11 occurs simultaneously by means of conventional control systems.

Advantageously, the machine Ia, Ib is provided with a plurality of supporting assemblies 4 and a plurality of transfer assemblies 7, each of which is jointly connected for sliding with a corresponding supporting assembly 4, which are distributed along the second axis A2, and a plurality of cutting assemblies 3, which are provided with respective rotating blades 5 which operate along respective cutting directrices which are parallel to the cutting direction T. Therefore, the connection means 6 comprise a pair of levers 12, each of which is arranged at a respective guiding element 14, for each supporting assembly 4. The first actuators 10 are moved simultaneously by the second actuators 11 so as to be arranged at the levers 12 of the supporting assembly 4. The machine Ia, Ib is thus provided with a management and control unit for coordinating the positioning of the cutting assemblies 3 according to the dimensional parameters of the work to be performed and of the supporting assembly 4 and the transfer assembly 7, so as to avoid interference between the rotating blades 5 and the elements of such assemblies during the cutting step. Such unit is of the type of a conventional PLC, which is not shown.

In a first embodiment (Figures 1-3) of the machine, indicated by the reference numeral Ia, each supporting assembly 4 is integrated in a respective transfer assembly 7; the cutting direction T and the advancement direction A are mutually parallel and transverse to the first and second axes, respectively Al and A2.

In this embodiment, the machine 1 a is particularly designed to cut an article M into a plurality of longitudinal strips, the width of which is determined by the placement of the cutting assemblies 3 along the first axis Al . Each supporting and transfer assembly 4≡7 comprises a supporting frame 15, which is associated slidingly with the guiding elements 14, and at least one flexible element 16, which is closed on itself so as to form a loop whose plane of arrangement is parallel to the cutting direction T and is wound around corresponding driving and driven wheels, respectively 17a and 17b, which are supported by the frame 15. The flexible element 16 preferably consists of a belt and, in plan view, it can be arranged laterally and proximately to the cutting directrix of a corresponding cutting assembly 3 during the cutting step. Moreover, each supporting and transfer assembly 4≡7 can have at least two flexible elements 16 which are arranged parallel to each other; during the cutting step, the supporting and transfer assembly 4≡7 can be arranged, in plan view, so that the cutting directrix of the corresponding cutting assembly 3 passes between the flexible elements 16. The machine Ia that is shown has two supporting and transfer assemblies 4≡7, which are provided with a single flexible element 16, arranged laterally and between which three supporting and transfer assemblies 4≡7 are interposed which are provided with a pair of flexible elements 16. The machine Ia is further provided with five cutting assemblies 3; during cutting, each cutting assembly 3 cooperates with a corresponding supporting and transfer assembly 4≡7, which supports the article M proximately to the corresponding cutting directrix.

It is noted that the possibility of arranging the flexible elements 16 proximately the cutting directrices makes it possible to ensure optimum support of the article M during cutting, minimizing the formation of rejects during work.

Advantageously, the machine Ia comprises means 18 for temporary retention of at least one and more preferably both perimetric bands of the article M which are arranged parallel to the cutting direction and means 19 for the evacuation of such bands from the remaining part of said article once they have been cut.

Advantageously, the retention means 18 support the perimetric bands over their entire length.

The retention means 18 provide adequate support of the article M being worked, since the two end cutting assemblies 3 work with the corresponding cutting directrices arranged laterally to the corresponding flexible elements 16 on the side directed toward the frame 2. Therefore, each perimetric band of the article M with respect to the cutting directrix rests with one side on the flexible element 16 of the supporting and transfer assembly 4≡7 that cooperates with the corresponding cutting assembly 3 and is supported on the other side by the retention means 18.

The retention means 18 comprise a first clamp and a second clamp, respectively 18a and 18b, which are actuated automatically and lie longitudinally and parallel to the cutting direction T and are adapted to retain respective perimetric bands of the article M. The first clamp 18a is associated with the frame 2 so that it can oscillate about an axis which is parallel to the cutting direction T, between a first position, in which it is clamped on the respective perimetric band during cutting, and a second position, which is inclined with respect to the first one and in which, after cutting, it releases such band, which is cut from the remaining portion of the article M, means for actuating the oscillation of the first clamp 18a being provided and not being shown because they are of a conventional type.

The second clamp 18b is associated with the frame 2 so that it can move alternately toward and away from the article M, and in the nearer position it is adapted to retain the corresponding perimetric band during cutting work and in the spaced position, once cutting has been performed, it is adapted to release said band cut from the remaining portion of the article M. Means are thus provided for actuating the movement of the second clamp 18b, such as one or more cylinders 19 which operate in a horizontal direction, whose jacket is jointly connected to the frame 2, and whose movable stem is associated with the second clamp 18b.

The evacuation means 19 consist of a chute 20, which is arranged below the support and transfer assemblies 4≡7 and on which the retention means 18 release the perimetric bands after cutting. In a second embodiment (Figures 4-7) of the machine Ib, each supporting assembly 4 is jointly connected, for translational motion along the second axis A2, to a corresponding transfer assembly 7, although the mechanical elements that provide the two functions are distinct. In this case, the cutting direction T is substantially transverse, and preferably perpendicular, to the advancement direction A, which in turn is substantially parallel to the first axis Al and to the second axis A2.

In this embodiment, the machine Ib is particularly designed to perform the transverse cutting of an article M that has been previously cut into a plurality of longitudinal strips arranged mutually adjacent so as to obtain a plurality of square tiles, whose dimension perpendicular to the cutting direction T is determined by the position of the cutting assemblies 3 along the first axis Al.

Each transfer assembly 7 consists of a framework 21, which is associated to the guiding elements 14 so that it can slide and supports at least one motorized roller 22, which is arranged so that its longitudinal axis is parallel to the cutting direction T. Moreover, each supporting assembly 4 consists of a comb-like structure, which is provided with at least one longitudinal element 23 arranged laterally adjacent to the roller 22, is associated with the framework 21 and can move alternately between a cutting configuration, in which the longitudinal element 23 protrudes upward with respect to the roller 22, with the article M resting on said longitudinal element, and a transfer configuration, in which the longitudinal element 23 is at a level that is substantially lower than the level of the roller 22, with the article M resting on said roller. During cutting, each supporting assembly 4 and the corresponding transfer assembly 7 can be arranged so that the longitudinal element 23, in plan view, is arranged proximately and laterally to the cutting directrix of the corresponding cutting assembly 3.

Preferably, the comb-like structure has a pair of longitudinal elements 23 arranged on opposite sides of each roller 22. In the figures, the machine Ib is provided with a plurality of supporting assemblies 4, which are coupled to respective transfer assemblies 7. The two transfer assemblies 7 arranged externally to the advancement direction A have two rollers 22 each, whereas the intermediate transfer assemblies 7 are provided with three rollers 22 each. The machine Ib has at least one third actuator 24 for the movement of the supporting assemblies 4 between the cutting and transfer configurations, such as one or more cylinders interposed between the frame 2 and the comb- like structure which operate in a vertical direction.

In practice it is possible to provide an apparatus for cutting articles M such as ceramic slabs so as to obtain a plurality of square tiles by arranging in series two machines according to the invention with the respective advancement directions A mutually aligned, the first machine Ia for the longitudinal cutting of the article M into a plurality of longitudinal strips according to the first embodiment shown in Figures 1-3 and the second machine Ib for transverse cutting of said strips arranged mutually adjacent so as to obtain square tiles according to the second embodiment shown in Figures 4-7.

The operation of the present invention is as follows.

At the beginning of the machining process, the user can set on the PLC the dimensions of the cuts to be performed, from which the arrangement of each cutting assembly 3 and of the supporting assembly 4 that cooperates therewith and of the corresponding transfer assembly 7 is generated.

For the positioning of each supporting assembly 4 and of the corresponding transfer assembly 7, the second actuators 11 are activated which arrange the first actuators 10 at the levers 12 for locking the supporting assembly in the active configuration. By means of the actuation of the first actuators 10, the levers 12 are moved into the inactive configuration, disengaging the sliding of the supporting assembly 4 and of the corresponding transfer assembly 7, jointly connected thereto and optionally integrated therein, along the second axis A2. Once the correct position depending on the work to be performed has been reached, the first actuators 10 release the levers 12, which with the help of the yielding means return to the active configuration, blocking the movement of the assembly. The arrangement of the supporting assembly 4 is such that the corresponding flexible elements 16 or longitudinal elements 23 are arranged laterally to the cutting directrix of the corresponding cutting assembly 3, so that no interference occurs during machining.

In the second embodiment (Figures 4-7), the third actuators 24 are activated during cutting so as to arrange the comb-like structure in the cutting configuration, with the article M rested on the longitudinal elements 23 and raised by the rollers 22.

In practice it has been found that the described invention achieves the proposed aim and objects, and in particular the fact is stressed that the machine according to the invention allows continuous and fully automated adjustment of the arrangement of the supporting and transfer assemblies depending on the arrangement of the cutting assemblies, calculated according to the dimensional parameters of the cuts to be performed.

Moreover, the machine according to the invention has an article crossing direction which is linear, according to the longitudinal orientation of the article, and is therefore well-suited to be installed in systems with a rectilinear flow of material.

The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. All the details may further be replaced with other technically equivalent elements.

In practice, the materials used, as well as the contingent shapes and dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.

The disclosures in Italian Patent Application No. MO2008A000320 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.