Technical Field

The present invention relates to an automatic computer controlled carving machine for the automated carving of materials such as wood, clay/ceramics, gypsum, stone or other suitable material and to a method of operating such a carving machine. The automatic computer controlled carving machine is controlled via a motion platform. A user reads data or carving data into a computer where the data is generated into machine controlling language or machine controlling data. The machine controlling language or machine controlling data is then used to control the motion platform in order to generate a carved pattern on an object to be carved such as for example a dried clay tile prior to firing.

Background of the Invention

Even today objects that are to be carved, in particular clay-/ceramic-tiles prior to firing, are carved manually by workers. Normally glazing is applied to the tiles prior to carving. The glazing may for example be a powder that is sintered during the firing process. In many cases the glazing is used to generate a specific colour of the ceramic tiles and/or to provide a shiny surface. In particular for architectural applications, for instance for the purpose of having a carved pattern or motif in a lobby of a building, carving is ongoingly popular. Typically the architect thereby designs a pattern or vector image that shall be carved on a wall. Such a pattern or vector image is normally carved on one or more tiles, very often clay- /ceramic-tiles prior to firing. This carving work is usually done far away from the place where the carved pattern will be installed in the end, since the carving work is a manual process and as such it is done where comparably cheap labour is available. After the carving work is done the tiles are normally fired at a high temperature. After firing the tiles are transported to the site where they will be installed.

Another application where carved tiles are used is for instance in lobbies or reception areas of companies where the logo or emblem of the company is carved out and installed on the wall, for instance on ceramic tiles. Also these ceramic tiles are even today manually carved and transported over long distances. The manual carving of tiles bears certain risks for the workers carving them, since the workers are subject to exposure to potentially dangerous ceramic dust.

The manual carving involves disadvantages such as high costs, long transportation and therefore high emissions, a long time to market due to the transportation and if a problem occurs on site, such as a faulty tile that does not match into the carved pattern or if a tile breaks on site, long waiting times.

The Object of the Invention

In view of the above an object of the invention is to provide an automatic, computer controlled carving machine for the carving of objects said carving machine getting rid of the above identified disadvantages.

Another object is to provide a carving machine that is economic and easy to handle.

Still another object is to provide a carving machine that increases the safety of the workers.

Still another object is to provide a method for operating a computer controlled carving machine for ensuring an efficient process.

Summary of the Invention

The inventor(s) of the automatic carving machine have realized that it is possible to automatically carve an object to be carved, preferably a clay-/ceramic- tile prior to firing. To do so the inventor(s) use a carving tool and move it along particular angles and movements via a motion platform for processing an object to be carved. Different movement patterns and different types of carving tools, which are described herein, can also be used in order to generate different impressions and looks of the carved pattern.

Herein the word clay refers to the raw material used to produce ceramic tiles. The clay may be a composite material in a doughy consistence comprising different minerals and any type of binder. The binder may comprise water, any type of silicate, bentonite or it may even be of organic origin. The clay may be dried after it has been brought into the final shape. The dried clay is then fired in an oven to generate ceramic material. The ceramic tile may or may not comprise a glazing layer. Disclosed herein is a computer controlled carving machine comprising a working area, a motion platform, a tool head coupled to the motion platform and a carving tool coupled to the tool head. The carving tool, which defines a longitudinal axis, can be moved and oriented in any direction in the three-dimensional space and any orientation via the motion platform and the tool head. In addition the carving tool may also be configured to be capable of rotating in between cuts but not more than +/- 90° around its longitudinal axis. Alternatively, the carving tool may be capable of being locked in predetermined rotational positions around the longitudinal axis for different cuts. During undergoing cuts the carving tool may however not be rotated. The working area is configured to receive a dried clay tile, said working area being arranged so that the dried clay tile to be carved is within the reach of the carving tool, wherein in order to perform a first cut the carving tool is brought into a surface of the dried clay tile at a first angle relative to a plane defined by the dried clay tile at a point of contact, and removed from the dried clay tile at a second angle relative to the plane defined by the dried clay tile, wherein the first angle is chosen of a range of 0° to 85° and wherein the second angle is chosen of a range of 1 ° to 179° minus the value of the first angle, whereby the carving tool is not rotating around its longitudinal axis during the first cut or any subsequent cut.

A blade of the carving tool may be arranged in a plane perpendicular to the longitudinal axis of the carving tool, with the blade pointing away from a free end of the carving tool.

The forward direction may be changed during the actual (first) cut and any subsequent cut. This allows to make for example angled cuts, curved cuts or a combination thereof as seen when looking onto the plane and onto the object to be carved.

The first and/or second angle describes the angle of the carving tool when it is entering the object to be carved and after the carving tool entered the object to be carved for the first time. During the first cut or in general during a cut the angle of the carving tool may be changed in order to generate various patterns of the (first) cut.

A computer controlled carving machine according to the above solves the objects by providing an efficient, fast and cost effective solution for producing carved objects. Additionally the carving machine enables a user to make use of a wide range of creative freedom.

Removing the carving tool at a second angle has further the effect of removing all loose material that has been cut out during the first cut.

The first angle may be chosen to be steady during the first cut or it may be configured to vary during the first cut or any subsequent cut.

The second angle may be chosen to be steady during the removal or it may vary.

When the first angle and the second angle have the same value and when they are congruent with one another, respectively, then the carving machine is only performing a cut, similar to a knife, but not an actual carving or scraping. This becomes clear when studying the figures, such as for example figure 3b. This may however be enough in particular when a dried clay tile is carved since the brittle nature of the dried clay may release a chip or flake of the clay. This may further depend on the shape of the blade/edge of the carving tool a thicker blade may lead to a chip while a thinner blade to a cut.

The first angle and the second angle may be chosen so that they are not congruent with one another.

After entering the dried clay tile the first angle may remain constant or it may change and once the removal of the carving tool starts the second angle may remain constant or it may change. The first angle and the changing angle may be chosen independently from each other of a range of 0° to 180°, preferably 0° to 90°, relative to the plane defined by the dried clay tile. The first angle and the second changing angle may even be chosen to be 0° or 90° or 180°, for instance when the carving tool shall scrape out a horizontal cut.

The carving tool may be designed as a so called chip breaker, which means that the carving tool is designed so that it automatically chips off a piece of the material or dried clay tile to be carved as soon as it performs a cut. This can be achieved for example by a cam surface that guides the chip/material accordingly and extends from the blade away from the dried clay tile.

The carving tool may be controlled by the motion platform and the tool head to perform a second cut at a distance of the first cut.

Most likely there may be many cuts involved, thus more than one hundred, to generate a carved pattern, the first and second cut are merely used to illustrate the process. It is very likely that the carving machine performs a lot of cuts or scrapes while creating a carved pattern.

In an embodiment the distance between the first cut and the second cut is greater than 0,01 mm.

The distance may be in the range of about 0.5mm to about 100mm in order to generate cuts that are separated from each other. The distance between the first and second cut or any consecutive cuts may be alternatively chosen to be very small in order to create a continuous cut that is almost groove-like, for instance when the carved pattern is a map and a river should be illustrated.

In an embodiment a longitudinal extension of the carving tool defines an longitudinal axis, said axis may be oriented oblique relative to the plane of the object to be carved at the point of contact of the carving tool on the object to be carved and said axis may be at least more or less parallel to the first angle.

The carving tool may be shaped as a V, a U, a half circle or any combination thereof as seen in a cross section cut perpendicular to the longitudinal axis of the carving tool. The cross section may be taken comparably close to the free end comprising the blade of the carving tool. The V, U, half circle or any combination thereof refer to the profile of the carving tool and its carving tip.

The carving tool may be shaped as a straight flat blade, a straight oblique flat blade, a pointed flat blade, a half round flat blade or any combination thereof.

In a preferred embodiment the object to be carved may be a clay tile before firing. The clay tile may comprise a glazing layer whereby the depth of the first cut and any subsequent cut, as measured in a direction orthogonal to the plane, is greater than the thickness of the glazing layer.

Since the depth of the (first) cut is greater than the thickness of the glazing layer, the carved pattern has a different colour than the surface (non-carved area) of the clay tile. The carving tool and thus the carving machine can achieve this by accentuating the colour of the clay in the cuts. Since the glazing layer typically is shiny or even has a colour, the carved pattern looks different not only for its structure but also for its colour. The thickness of the glazing layer is typically less than 1 mm. Thus the carving tool does not need to carve very deep in order to accentuate the colour of the clay.

The clay tile or object to be carved may alternatively also be provided without a glazing layer. This does not affect the carving process. Disclosed herein is further a method of operating a computer controlled carving machine, said carving machine comprising a working area, a motion platform, a tool head and a carving tool, which defines a longitudinal axis, comprising the steps of:

- feeding machine controlling language or machine controlling data into the carving machine for steering the tool head and the carving tool via the motion platform; and

- moving the tool head to a point of contact on a dried clay tile to be carved The method further comprises the steps of:

- performing a first cut by bringing the carving tool into a surface of the dried clay tile at a first angle relative to a plane defined by the dried clay tile at a point of contact;

- removing the carving tool from the dried clay tile at a second angle relative to the plane in order to complete the first cut, wherein the first angle is chosen of a range of 0° to 85° and wherein the second angle is chosen of a range of 1 ° to 179° minus the value of the first angle, whereby the carving tool is not rotating around its longitudinal axis during the first cut or any subsequent cut.

During the first cut and any subsequent cut the carving tool may be moving in a direction in the plane defined by the dried clay tile, said direction being defined by the orientation of an edge of a blade of the carving tool.

By operating a computer controlled carving machine according to the above method it is possible to generate carved patterns automatically and at the same time to avoid destroying the dried clay tile.

The method may further comprise the step of performing a second cut with the carving tool at a distance of the first cut.

In a further embodiment the method may comprise the step of adapting any of the distance, the first angle, the second angle between the first cut and the second cut in order to generate different carving patterns on the dried clay tile.

As previously mentioned, this may help to create various styles of carved patterns comprising cuts that look like continuous grooves or independent cuts, separated from each other or any combination thereof. Brief Description of the Drawings

The present invention will now be described, for exemplary purposes, in more detail by way of embodiments and with reference to the enclosed drawings, in which:

Fig. 1 schematically illustrates a perspective view of a part of a carving machine and an object to be carved;

Fig. 2 schematically illustrates a perspective view of a carving tool of the carving machine and the object to be carved;

Fig. 3a schematically illustrates a cross section through the carving tool and the object to be carved;

Fig. 3b schematically illustrates a cross section through a first cut in the object to be carved, the first cut being cut according to the illustration of figure 3a;

Fig. 4 schematically illustrates a cross section through the object to be carved illustrating an example of an alternative first cut;

Fig. 5 schematically illustrates a cross section through the object to be carved illustrating an example of a further alternative first cut;

Fig. 6 schematically illustrates a cross section through the object to be carved illustrating an example of even a further alternative first cut;

Fig. 7a schematically illustrates a cross section through the carving tool and the object to be carved illustrating a distance between the first and second cuts;

Fig. 7b schematically illustrates a cross section through a first cut and a second cut in the object to be carved, the first and second cuts being cut according to the illustration of figure 7a;

Fig. 8a schematically illustrates a cross section through the carving tool and the object to be carved illustrating another distance between the first and second cuts;

Fig 8b schematically illustrates a cross section through the first cut and the second cut in the object to be carved, the first and second cuts being cut according to the illustration of figure 8a; and

Fig. 9 schematically illustrates a method for automatically carving an object. Detailed Description of Preferred Embodiments

Fig. 1 illustrates a part of a computer controlled carving machine 1 comprising a motion platform 4 (only partially shown), a tool head 2 and a working area 6 comprising an object to be carved 16. In figure 1 the motion platform 4 is not shown in its entirety mainly a connection element of the motion platform 4 is illustrated, since, as further described below, the motion platform 4 may be any type of automatic controllable machine. The tool head 2 comprises a carving tool 8. The carving tool 8 is fixedly connected to the tool head 2, it may however be removable in order to exchange it for other types of carving tools (not shown) depending on the requirement of the carved pattern. In the illustrated version of the carving machine 1 the object to be carved 16 is a clay tile prior to firing. The working area 6 may comprise means for holding the object to be carved. Such means may include rubber strips, pressure pistons, brackets, screws, suction cups or any other suitable configurations. The motion platform 4 is only partially illustrated for simplicity reasons. The motion platform 4, to which motion platform 4 the tool head 2 is coupled to, may be any suitable type such as a Cartesian moving platform, a Selective Compliance Assembly Robot Arm (SCARA), an articulated robotic arm, a delta robot system, a Stewart platform or any type of parallel robotic arm. These robot types are generally known and they are widely used.

Figure 2 illustrates an enlarged view of the carving tool 8 and the object to be carved 16 right after a first cut 12 has been performed. The first cut 12 is performed by entering the carving tool 8 into the surface of the object to be carved at a first angle a (c.f. figure 3a) relative to a plane of the object to be carved at a point of contact. In the present case with a dried clay tile, the plane is parallel to the plane defined by the clay tile, this may however be different if a three dimensional object is carved. The tool head 2 and the motion platform 4 may be configured to adjust the orientation of the carving tool 8 to any types of shapes of the object to be carved. The carving tool 8 is then pressed into the surface at the same first angle or at a first angle that is changing and removed from the object to be carved at a second angle β (illustrated in figure 3a) or at a second angle that is changing relative to the plane defined by the dried clay tile, whereby the carving tool is moving in a forward direction b on the object to be carved during the first cut. Figure 2 further illustrates the position of a blade 9 of the carving tool 8. The blade 9 of the carving tool 8 is arranged at a free end of the carving tool and wherein an edge of the blade 9 is pointing away from said free end in a direction at least more or less parallel to the longitudinal axis a of the carving tool 8.

The forward direction b is defined by the direction in which the edge of the blade 9 is pointing.

The forward direction b (figure 2) may also be changed in between two consecutive cuts, for example in between the first cut 12 and the second cut 14 by rotating the carving around a perpendicular to the plane defined by the dried clay tile.

As can be seen from figure 2 the first cut 12 has a triangular shape. This shape depends on the type of the carving tool 8 used. In the illustrated case it is a V-shaped carving tool 8. Any other type of carving tool may however be used such as for example: a V-shaped as illustrated, a U shaped, a half circle or any combination thereof. Alternatively the carving tool 8 may be shaped as a straight flat blade, a pointed flat blade, a half round flat blade, a curved flat blade or any combination thereof.

Figure 3a illustrates a cross section cut through the carving tool 8 and the object to be carved 16 and the intended first cut 12. The first angle a and the second angle β are well illustrated in figure 3a. The first angle a is measured between the plane at the point of contact on the object to be carved 16 and the direction of movement of the carving tool 8. The inclination of a longitudinal axis a defined by the longitudinal extension of the carving tool 8 may be parallel to the first angle a or differ from it. An at least more or less parallel orientation of the longitudinal axis a eases the cutting itself since the blade or the tip of the carving tool 8 is aligned with the direction of movement.

The second angle β is also measured between the plane and the direction of movement of the carving tool 8. During the removal of the carving tool 8 from the object to be carved 16, the blade of the carving tool 8 and direction of movement are not aligned. The reason for this is that carved out material will be removed when the carving tool 8 is removed in such a manner.

Figure 3b illustrates a cross section through the first cut 12 according to figure 3a in the object to be carved 16. In the example of figures 3a and 3b the first angle and the second angle are kept constant at the value of the first angle a and the value of the second angle β, respectively.

The value of the first angle a may be chosen to be in a range of 0° to 85°. The value of the second angle β may be chosen to be in a range of 1 ° to 179° minus the value of the first angle (a). The angle at the tip or lowest point of the first cut 12 may be around 90°. However the angle at the lowest point of the first cut 12 may also be different from 90°.

Figures 4 to 6 illustrate the various different first cuts 12', 12", 12"' that are possible in the object to be carved 16 with the computer controlled carving machine 1 and the method of operating the carving machine 1 . The first cut 12', 12", 12"' may be curved 12' as illustrated in figure 4, it may be a combination of straight and curved 12" as illustrated in figure 5 or it may even be more complex 12"', such as illustrated in figure 6. In the first cuts 12', 12", 12"' the first angle and/or the second angle have been varied during the actual cut in order to generate the shown first cuts 12', 12", 12"'. The first angle and the second angle may by chosen independently from one another in a range from about 0 to 180° or 0° to 90° and 180° to 0 or 90° to 0°, respectively, when measured in the same way as illustrated for the first angle a and the second angle β, respectively.

As an example, when the first changing angle is 0° then the carving tool 8 is moving parallel to the plane in the object to be carved 16.

As a further example, the carving tool 8 may move orthogonal to the plane downwards or upwards when the first angle a is 90° or the second angle β is 90°.

Figure 7a illustrates a cross sectional view of the carving tool 8 and how a first cut 12 and a second cut 14 can be done. The carving tool 8 is shown in drawn lines and dashed lines in order to illustrate how it is moving between the first cut 12 and the second 14 and any consecutive cut (not shown). The distance d between the first cut 12 and the second cut 14 is well shown in figure 7a and figure 7b illustrates the resulting first cut 12 and second 14 in the object to be carved 16.

The distance d may be varied between the first cut 12 and the second cut 14 and any subsequent cut, as figures 8a and 8b illustrate. The distance d is not a fixed distance it may be greater than 0.01 mm, preferably greater than 0.5mm but it is however possible to have the distance d at a very small value in order to create an almost groove-like cut. Figures 7 a to 8b only illustrate a possible shape of the first cut 12 and the second cut 14, any other shape is conceivable as for instance illustrated in figures 4 to 6 in order to create a carved pattern.

Further, although not illustrated it is even possible to rotate or turn the carving tool 8 in the plane while doing the (first) cut, thus in other words changing the direction b of movement (c.f. figure 2) of the carving tool 8 while carving the object to be carved 16 and in between subsequent cuts.

Between or during the first cut 12, the second cut 14 and any subsequent cut any of the described parameters such as distance d, forward direction b, first angle a, second angle β, may be changed or varied.

Figure 9 illustrates a method of operating an automatically controlled carving machine 1 , said carving machine 1 comprising a working area 6, a motion platform 4, a tool head 2 and a carving tool 8 and comprises the steps of:

- feeding S01 machine controlling data into the carving machine 1 for steering the tool head 2 and the carving tool 8 via the motion platform 4;

- moving S02 the tool head 2 to a point of contact on an object to be carved 16;

- performing S03 a first cut 12 by bringing the carving tool 8 into a surface of the object to be carved 16 at a first angle a relative to a plane of the object to be carved 16 at a point of contact;

- pressing S03 the carving tool 8 into the surface of the object to be carved 16 at the same first angle a or at a first angle that is changing; and

- removing S04 the carving tool 8 from the object to be carved at a second angle β relative to the plane or at a second angle that is changing in order to complete the first cut 12.

The forward direction b may change in between cuts, for example in between the first cut 12 and the second cut 14. Thus the forward direction b is not a fixed parameter of the cutting method.

After completion of the first cut 12, the method may comprise the step of checking S05 if the carved pattern is finished.

If the carved pattern is finished the carving machine 1 may signal S08 this to the user so that the carved object can be automatically or manually removed from the working area 6. If the pattern is not finished the method comprises the step of optionally changing S06 any of the distance d, the first angle a and/or the second angle between the first cut 12 and the second cut 14 in order to generate different carving patterns on the object to be carved 16. In a further step S07 the steps S01 to S06 may then be repeated to generate a carved pattern.

Even though the tool head 2 is illustrated for example in figure 1 , it may also be shaped and designed in a different way.

The step of pressing S03 the carving tool 8 into the object to be carved may ensure that the carving tool 8 is pressed into the surface of the object to be carved so that a glazing layer (not shown) on the object to be carved is passed. The carving tool may advance to a depth, as measured in a direction orthogonal to the plane, below the glazing layer.

As one may conceive such a carved pattern is very likely to contain a plurality of cuts, somewhere in the hundreds to thousands and not just a few such as 1 to one hundred.