Patent Description:
In particular, the present invention relates to the technical sector for obtaining bevelled tiles by means of cutting from a larger slab.

In the present description, for the sake of easier description, the term "slab" will be used to indicate a rough element which is yet to be cut into strips or tiles, the term "strip" will be used to indicate a strip of material which will then be cut into tiles, and the term "tile" will be used for a generally smaller element obtained by cutting the slab or strip. "Tile" will therefore also indicate panels having fairly large dimensions. The purpose of said simplification is merely to make reading of this text easier, without however having any limiting effect on the scope of protection as defined by the appended claims.

It is known that there exists a need to obtain slabs which are bevelled and cut-to-size. In fact, the tiles have rough edges such that often the edges of the tile must be chamfered. The chamfer is referred to by the term "bevel" and for example may be inclined at <NUM> degrees or curved.

A widely used technical solution, by means of which bevelled tiles may be obtained, involves the use of two types of machine in succession: a cutting machine and a bevelling machine which may be arranged in line, but separate from each other.

The cutting machine may be a conventional cutting machine which, for example, may have two lateral support structures above which at least one beam is slidable, resting with its ends on the lateral support structures. A sleeve-holder carriage having, mounted thereon, a vertically sliding sleeve travels along the at least one beam. A machining head with a spindle adapted to be equipped with a diamond cutting disc is mounted on the sleeve. Machines of this type are described for example in patent application <CIT>.

The bevelling machine may instead be provided with a series of inclined-axis pneumatic spindles arranged parallel with each other and equipped with lapping tools able to form the bevel along an edge of the tiles.

The use of these two machines arranged in succession to obtain a finished product has a number of drawbacks. Firstly it is a very costly solution since two separate machines are required. Secondly, it is a solution which is not very efficient since it increases considerably the overall machining time. In fact, in order to pass from one type of machining operation to another one, it is required to remove the material from a machine, move it to another machine and reposition the material. This repositioning of the tiles from the cutting machine to the bevelling machine may also give rise to a loss of precision. Moreover, adjusting the alignment of the bevelling machine with respect to the tiles is further complicated if the parts to be bevelled have dimensions or shapes which are very different from each other.

It has also been noticed that, when the bevel is performed after cutting the slab, if the latter is not performed with extreme precision or if the slab has thicknesses which differ, even slightly, with respect to the nominal thickness, a non-optimum bevel, with dimensional variations along the edge of the tile, will be obtained.

Finally, the movement of the material is an operation which may require the assistance of an operator, which could result in further positioning imprecision and which in any case represents a cost which must be added to the final product.

In order to overcome these drawbacks a composite machine adapted to perform both the cutting operations and the bevelling operations has been developed. In machines of this type, the spindle is equipped with a cutting disc and with an axially mounted bevelling tool which may be attached to or removed from the spindle of the cutting disc by means of a releasable connection. In this way the bevelling tool may be used to form a bevel and then removed so that the slab may be cut with the cutting disc.

This type of machine may also be provided with a guiding device which allows the bevelling disc to perform incisions or pre-cuts in the slab always to the same depth, irrespective as to any irregularities on the surface of the slab, so as to obtain an edge with a regular and uniform bevel.

Machines of this type are described for example in international patent application <CIT>.

However, even these machines, although widely used and popular, are not without drawbacks.

Firstly they have a limited productivity since the bevelling tool must be constantly mounted and removed and this requires machine stoppages which increase the machining time.

Another drawback is that, once the bevelling tool has been removed, it is necessary to align the cutting disc with the cut which has been previously made and this may result in a lack of precision and/or an increase in the manufacturing times for the finished product.

<CIT> discloses a machine as per the preamble of claim <NUM>.

The object of the invention is therefore to overcome substantially the drawbacks of the prior art.

A first task of the present invention is to reduce the times and costs necessary for obtaining strips or tiles with bevelled edges from a slab.

A second task of the present invention is to provide a technology where cutting of the slab and bevelling of the edges of the tile may be performed in a single simple and low-cost combined cutting and bevelling machine.

A third task of the present invention is to provide a technology in which realignment of the cutting disc with respect to the cut previously made by the bevelling disc is no longer required.

Moreover the aim is to provide a combined cutting and bevelling machine which is able to produce a uniform bevel along the whole edge of the tile and/or the strip.

The object and tasks are achieved with a combined cutting and bevelling machine for slabs of stone or stone-like material according to claim <NUM>.

In particular, the invention relates to a machine comprising at least one work unit provided with a cutting unit and a bevelling unit, wherein the cutting unit comprises a cutting spindle and the bevelling unit comprises a bevelling spindle.

Further advantageous characteristic features according to the present invention are indicated in the dependent claims.

The advantages and characteristic features of the present invention will emerge more clearly from the detailed description below of a number of examples of embodiment provided by way of a non-limiting example, with reference to the attached drawings in which:.

The machine <NUM> comprises at least one work unit <NUM> provided with a cutting unit <NUM> and a bevelling unit <NUM>, wherein the cutting unit <NUM> comprises a cutting spindle <NUM> and the bevelling unit <NUM> comprises a bevelling spindle <NUM>.

The cutting spindle <NUM> is mounting a cutting disc <NUM>. The bevelling spindle <NUM> is mounting a bevelling disc <NUM>.

The machine <NUM> comprises a workpiece support bench <NUM>. In accordance with a possible embodiment of the present invention, the workpiece support bench <NUM> may be rotatable about a vertical axis. Advantageously a drive unit (not shown) may be provided for rotation of the workpiece support bench <NUM>.

Furthermore, the workpiece support bench <NUM> may be provided with an automated conveyor belt <NUM> for feeding a slab <NUM>. Advantageously, the conveyor belt <NUM> may be made of expendable material suitable for receiving incisions.

In accordance with the present invention, the at least one work unit <NUM> is movable above the workpiece support bench <NUM> along a beam <NUM> slidable on two lateral support structures <NUM>, <NUM>. This type of structure, since it is well-known to the person skilled in the art, will not be further described.

According to a possible embodiment of the present invention, the at least one work unit <NUM> comprises:.

The work unit <NUM> also comprises a machining head <NUM> equipped with the cutting unit <NUM> and with the bevelling unit <NUM>.

As can be seen in <FIG>, the machining head <NUM> comprises a support piece <NUM> adapted to be connected to the sleeve <NUM>. The cutting spindle <NUM>, on which the cutting disc <NUM> is mounted, is housed on the support piece <NUM>. This cutting spindle <NUM> may be operated by first drive means <NUM>.

In the embodiment shown in <FIG>, the first drive means <NUM> comprise an electric motor, which has its axis perpendicular to the workpiece support bench <NUM>.

The support piece <NUM> is provided with elements designed to connect the support piece <NUM> to the sleeve <NUM>.

Since the support piece <NUM> is rigidly connected to the sleeve <NUM>, the machining head <NUM> is also movable towards or away from the workpiece support bench <NUM>. Advantageously, the machining head <NUM> moving along this direction is movable between two configurations: a rest configuration (shown in <FIG>) and a cutting configuration (shown in <FIG>, <FIG>).

The rest configuration is understood as meaning a position of the machining head <NUM> where the cutting disc <NUM> is raised from the workpiece support bench <NUM> and is no longer designed to engage with the slab <NUM>, while a cutting configuration is understood as meaning a position of the machining head <NUM> where the cutting disc <NUM> is lowered towards the workpiece support bench <NUM> and is designed to engage with the slab <NUM> over the entire thickness of the said slab. In this position, the cutting disc may perform cuts in the expendable support surface on the workpiece support bench <NUM> to a depth of <NUM>-<NUM>.

According to a possible embodiment of the present invention, not shown in the attached figures, the machining head <NUM> may be adapted to rotate the cutting spindle <NUM> about a first axis substantially perpendicular to the workpiece support bench <NUM> and therefore vertical. This allows the machining head <NUM> to perform cuts in directions inclined in the horizontal plane with respect to the longitudinal direction of the workpiece support bench <NUM> which coincides with the direction of feeding of the slab <NUM>.

According to an alternative embodiment, the machining head <NUM> may be a bi-rotational head, i.e. a head adapted to rotate a cutting spindle <NUM> about a first axis substantially perpendicular to the workpiece support bench <NUM> and about a second axis, inclined with respect to the first axis. The second axis of rotation may be preferably perpendicular to the first axis. This allows the machining head <NUM> to perform cuts also in directions inclined with respect to the direction of the first axis, i.e. to the vertical direction. This embodiment of the machining head is not shown in the attached drawings; however it is known per se to the person skilled in the art.

According to a further embodiment, the machining head <NUM> may be of the fixed direction type. It is clear that a fixed-direction machining head <NUM> simplifies the constructional design compared to heads which may allow rotation about one or more axes. In this case, the workpiece support bench <NUM> may be rotatable. In this way, the inability of the machining head <NUM> to perform transverse cuts is compensated for.

The cutting unit <NUM>, in the vicinity of the cutting disc <NUM>, may be preferably provided with nozzles (not shown in the figures) for dispensing a cooling fluid with the dual function of cooling the cutting disc <NUM> which may overheat during the cutting step and cleaning the machining waste from the slab <NUM>.

In accordance with the present invention, the axis of rotation of the cutting disc <NUM>, which is indicated in the attached figures by the reference number <NUM>, is parallel to the axis of rotation of the bevelling disc <NUM>, which is indicated in the attached figures by the reference number <NUM>.

With reference to <FIG>, the cutting disc <NUM> and bevelling disc <NUM> lie in the same plane. As shown in the configuration of <FIG>, the two discs <NUM> and <NUM> are aligned so that a bevelling operation and a subsequent cutting operation may be performed without having to reposition the machining head <NUM>.

The machining head <NUM>, in addition to the cutting unit <NUM>, also comprises the bevelling unit <NUM>.

The bevelling unit <NUM> comprises the bevelling spindle <NUM> on which the bevelling disc <NUM> is mounted. This bevelling spindle <NUM> may be operated by second drive means <NUM>.

In the embodiment shown in <FIG>, the second drive means <NUM> comprise an electric motor, which has its axis perpendicular to the workpiece support bench <NUM>.

The machining head <NUM> therefore comprises in a single head both the cutting unit <NUM> and the bevelling unit <NUM> with the respective spindles <NUM> and <NUM>, so as to perform in succession the bevelling step, shown for example in <FIG>, and a step for cutting the slab <NUM>, shown for example in <FIG>. In this connection, the machining head <NUM> must be such that the bevelling unit <NUM> is positioned in front of the cutting unit <NUM>. In fact, if the cutting operation were to be performed first, followed by the bevelling operation, the tiles cut from the slab <NUM> could be subject to a relative displacement and therefore might not be situated in an optimum position for the bevelling operation.

In accordance with a possible embodiment of the present invention, the bevelling unit <NUM> may be connected to the support piece <NUM> by supporting means <NUM>.

Moreover, the supporting means <NUM> may allow the movement of the bevelling unit <NUM> between a retracted configuration and an extracted configuration.

"Retracted configuration" is understood as meaning a configuration in which the bevelling disc <NUM> is not operative, while "extracted configuration" is understood as meaning an operating condition in which the bevelling disc <NUM> may cut into a slab <NUM> being machined.

The movement of the bevelling unit <NUM> between the two configurations may be performed manually by an operator. For this purpose, locking means (known per se to the person skilled in the art) may be provided for locking the bevelling unit in the two configurations.

Alternatively, the supporting means <NUM> may comprise a linear actuator <NUM> designed to move the bevelling unit <NUM> towards or away from the workpiece support bench <NUM>.

According to a further embodiment, the supporting means <NUM> comprise a linear actuator <NUM> which has two ends: a first end <NUM> connected by means of an actuator hinge <NUM> to the support piece <NUM>, and a second end <NUM> connected by means of a second actuator hinge <NUM> to the bevelling unit <NUM>.

The first actuator hinge <NUM> may be formed by a bracket which is arranged on the support piece <NUM> and on which a pin provided on the first end <NUM> rotates.

The second actuator hinge <NUM> may consist of a bracket arranged on the bevelling unit <NUM> and a pin arranged on the second end <NUM>.

Moreover, the supporting means <NUM> comprise a third hinge <NUM> between the bevelling unit <NUM> and the support bracket <NUM>, such that the bevelling unit is adapted to rotate about the axis of the third hinge <NUM> substantially parallel to the axis of rotation of the bevelling disc.

In the embodiment shown in <FIG> the linear actuator <NUM> is a pneumatic actuator with a cylinder <NUM> having a rod <NUM>. The cylinder <NUM> is connected to the support piece by means of the first hinge <NUM> and the rod <NUM> is connected to the bevelling unit <NUM> by means of the second hinge <NUM>.

The retracted configuration of the bevelling unit <NUM> where the bevelling disc <NUM> is not operative coincides with retraction of the linear actuator <NUM>, as shown in <FIG>. During this retraction movement, the rod <NUM> is sufficiently inserted inside the cylinder <NUM>, forcing the bevelling unit <NUM> to rotate along a curved arc away from the workpiece support bench <NUM>. The bevelling unit <NUM> moves until it reaches a retracted configuration.

The operative configuration of the bevelling unit <NUM>, where the bevelling disc <NUM> may cut into a slab <NUM>, coincides with extension of the linear actuator <NUM>, as shown in <FIG>. During said extension, the rod <NUM> is displaced, extending outwards relative to the cylinder <NUM>, forcing the bevelling unit <NUM> to rotate along a curved arc towards the workpiece support bench <NUM> about the axis of the third hinge <NUM>. The bevelling unit <NUM> moves until it reaches an operative configuration.

The extracted and retracted configurations of the bevelling unit <NUM> may be combined with the movement of the whole machining head <NUM> between a rest configuration and a cutting configuration.

A configuration is possible where the machining head <NUM> is in the rest configuration and the bevelling unit <NUM> is the retracted configuration (<FIG>).

Another configuration is also possible where the machining head <NUM> is in the cutting configuration and the bevelling unit <NUM> is the retracted configuration (<FIG>).

A further configuration is possible where the machining head <NUM> is in the cutting configuration and the bevelling unit <NUM> is the extracted configuration (<FIG>). It is clear that in this configuration at the start of machining of the slab <NUM>, only the bevelling disc <NUM> will engage the slab <NUM> (<FIG>) and only subsequently, for example with the advancing movement of the machining head <NUM> along the direction of the beam <NUM>, also the cutting disc <NUM> will engage with the slab <NUM> (<FIG>).

Should it be necessary to use only the cutting disc <NUM> and not the bevelling disc <NUM>, the machining head <NUM> may assume the cutting configuration with the bevelling unit <NUM> in the retracted configuration (<FIG>).

In accordance with a possible embodiment of the present invention, the rod <NUM> may be covered by a protection piece <NUM> adapted to prevent the entry into the cylinder <NUM> of any waste matter produced by machining.

According to a possible embodiment of the present invention, the bevelling unit <NUM> may be provided with a protection element or cowl <NUM> (see for example <FIG>).

In accordance with a possible embodiment of the present invention, the protection element or cowl <NUM> may be opened so as to allow access in order to service or replace the bevelling disc <NUM>. Advantageously the protection element or cowl <NUM> may be provided with a hatch <NUM> rotatable about the cowl hinges <NUM> and kept in a closed position by locking elements <NUM>.

According to a possible embodiment of the present invention, the bevelling unit <NUM> may be provided with nozzles for dispensing a cooling fluid with the dual function of cooling the bevelling disc <NUM> which may overheat during a bevelling step and cleaning the machining waste from the slab <NUM>. According to a possible embodiment of the present invention, the bevelling unit <NUM> may be provided with locating or adjustment means <NUM>. The locating means <NUM> allow a constant distance to be kept between the surface of the slab <NUM> being machined and the axis of rotation of the bevelling disc <NUM>.

It is therefore clear that the locating means <NUM> act so that the depth of the incision made by the bevelling disc <NUM> is always that pre-set by the operator and remains constant for the whole of the machining operation. In this way, the locating means <NUM> are able to compensate for any variations in the thickness of the slab <NUM> which occur during the advancing movement of the machining head <NUM>.

According to a possible embodiment of the present invention, the locating means <NUM> may comprise optical means, such as a laser spacing meter.

According to another possible embodiment of the present invention, the locating means <NUM> may comprise a rubberized wheel <NUM>.

In the embodiment shown in <FIG>, the rubberized wheel <NUM> is located alongside the bevelling disc <NUM>.

Advantageously the rubberized wheel <NUM> may be mounted idle.

The rubberized wheel <NUM> may be made to move by the movement of the machining head <NUM>. In <FIG> and <FIG> it can be noted that the position of the rubberized wheel <NUM> may be adjusted along a direction substantially perpendicular to the workpiece support bench <NUM>. Consequently, the relative position of the rubberized wheel <NUM> with respect to the bevelling disc <NUM>, and in particular with respect to its bottom edge, may therefore be varied. As a result it is possible to define a plurality of different depths of the incision made by the bevelling disc <NUM>.

According to a possible embodiment of the present invention, the adjustment of the position of the rubberized wheel <NUM> with respect to the bevelling disc <NUM> may be performed manually by an operator.

The adjustment of the position of the rubberized wheel <NUM> with respect to the bevelling disc <NUM> may be performed by means of an eccentric pin <NUM>. In <FIG> it can be noted that the eccentric pin <NUM> may comprise a first part <NUM> and a second part <NUM>, which are both cylindrical, the first part <NUM> and the second part <NUM> having axes which are parallel, but do not coincide.

According to a possible embodiment of the present invention, the eccentric pin <NUM> may be mounted on the shaft on which the bevelling disc <NUM> is mounted.

Alternatively, the eccentric pin <NUM> may be mounted on the protection element or cowl <NUM>. In particular, the first part <NUM> of the eccentric pin <NUM> may be adapted to engage with the protection element or cowl <NUM> of the bevelling unit <NUM>.

In accordance with a possible embodiment, the hatch <NUM> of the protection element or cowl <NUM> may be provided with a through-hole <NUM> inside which the first part <NUM> of the eccentric pin <NUM> may be seated.

The through-hole <NUM> may be coaxial with the axis of rotation of the bevelling disc <NUM>.

It is evident that, when the first part <NUM> rotates, the second part <NUM> also rotates, but eccentrically with respect to the first part <NUM>. By so doing, the second part <NUM> may assume different relative positions with respect to the axis of rotation of the bevelling disc <NUM>. Advantageously, the rubberized wheel <NUM> may be mounted on the second part <NUM>. According to an embodiment, the first part <NUM>, in order to be rotationally guided, may comprise a bottom surface <NUM> having a recess <NUM>, formed by containing edges <NUM>, <NUM>, and a hole <NUM>, positioned in the centre of the bottom surface <NUM> (see <FIG>).

The recess <NUM> is adapted to seat a first end <NUM> of a lever <NUM> which also has a second free end <NUM>. The first end <NUM> is pivotably mounted by means of fixing means <NUM>, the shank of which is received inside the hole <NUM>. Owing to the cooperation between the fixing means <NUM> and containing edges <NUM>, <NUM>, the first end <NUM> of the lever <NUM> is locked together with the first part <NUM> of the eccentric pin <NUM>. It is clear that, when the second end <NUM> is operated, the lever <NUM> rotates and, at the same time, the first part <NUM> and the second part <NUM> of the eccentric pin <NUM> also rotate, the second part <NUM> rotating eccentrically with respect to the first part <NUM> and the lever <NUM>.

The second end <NUM> of the lever <NUM> may be provided with a ring-type gripping handle <NUM> in order to facilitate movement of the lever <NUM>.

Moreover, the lever <NUM> may be provided with a control knob <NUM> provided with a pin adapted to engage with holes <NUM> formed in the protection element <NUM> and positioned along a circumference having its centre coinciding with the centre of the bottom surface <NUM> of the first part <NUM> of the eccentric pin <NUM>.

In this way, for heightwise adjustment of the rubberized wheel <NUM>, the following steps must be performed:.

In this way it is possible to arrange the rubberized wheel <NUM> in a predefined heightwise position with respect to the bevelling disc <NUM>.

In accordance with a possible embodiment, the movement of the bevelling unit <NUM> may be further controlled by means of a rod locking brake <NUM>.

As can be seen in <FIG>, the brake <NUM> is formed by a pneumatic cylinder <NUM> provided with a chamber <NUM> containing a piston <NUM>, provided with a wedge-shaped portion <NUM>, and a U-shaped element <NUM>, provided with first and second flanges <NUM>, <NUM>, between which the wedge-shaped portion <NUM> is able to slide.

Opposite the flanges <NUM>, <NUM>, coaxial holes <NUM>, <NUM> extending in a direction substantially perpendicular to the direction of the piston <NUM> are provided. The coaxial holes <NUM>, <NUM> are adapted to receive a guide rod <NUM> adapted to guide the first and second flanges <NUM>, <NUM> towards or away from each other.

The flanges <NUM>, <NUM> are also provided with tapered holes <NUM>, <NUM> which are substantially parallel to the coaxial holes <NUM>, <NUM> and inside which the rod <NUM> of the linear actuator <NUM> slides.

In the case where the cylinder <NUM> is not energized, the piston <NUM> does not act on the first and second flanges <NUM>, <NUM> which are therefore inclined with respect to each other, locking the rod <NUM> owing to the friction which is generated between the tapered holes <NUM>, <NUM> and the rod <NUM> itself (<FIG>). In this way, by locking the rod <NUM>, the bevelling unit <NUM> may also be locked in a predetermined position.

If the cylinder <NUM> is energized, the piston <NUM> via its wedge-shaped portion <NUM> (<FIG>) acts on the first and second flanges <NUM>, <NUM>, splaying them. This results in slackening of the friction between the tapered holes <NUM>, <NUM> and the rod <NUM>, allowing the rod <NUM> to slide freely and therefore the bevelling unit <NUM> to be moved.

Advantageously, the presence of the rod locking brake <NUM> ensures that the bevelling unit <NUM>, when it is in the extracted position and removed from the slab at the end of the bevelling step, does not move downwards suddenly and cut into the conveyor belt <NUM>. This because the rod locking brake <NUM> is energized and therefore the rod <NUM> is able to slide freely during machining, allowing the rubberized wheel <NUM> to rest constantly against the surface of the slab, rolling thereon; when the unit is removed from the slab, the brake is locked and therefore sudden lowering is prevented.

The above description clearly highlights features of the combined cutting and bevelling machine for slabs of stone or stone-like material according to the present invention, as well as the associated advantages.

Claim 1:
Combined cutting and bevelling machine (<NUM>) for slabs of stone or stone-like material, comprising a workpiece support bench (<NUM>) and at least one work unit (<NUM>) movable above the workpiece support bench (<NUM>) along a beam (<NUM>) slidable on two lateral support structures (<NUM>, <NUM>) and provided with a cutting unit (<NUM>) and a bevelling unit (<NUM>), whereby
the cutting unit (<NUM>) comprises a cutting spindle (<NUM>) mounting a cutting disc (<NUM>) and characterized in that
the bevelling unit (<NUM>) comprises a bevelling spindle (<NUM>) mounting a bevelling disc (<NUM>), and in that the cutting disc (<NUM>) and the bevelling disc (<NUM>) lie in the same plane; and
in that said at least one work unit (<NUM>) comprises a machining head (<NUM>) equipped with the cutting unit (<NUM>) and with the bevelling unit (<NUM>).