The present invention relates to a machine for the inkjet decoration of ceramic manufactured articles.

Background Art

The present invention finds special application in the decoration of visible surfaces having reliefs, recesses, depths or areas differentially inclined to each other.

Inkjet printing devices have long been used in the ceramics industry. These devices comprise one or more printing heads consisting of a plurality of nozzles, placed along at least one line, typically a straight line, which emit controlled jets of micro-droplets of ink, taken from a tank or a cartridge.

The printing head is controlled by an electronic processor that gives a sequence of printing controls to the various nozzles, depending on the image to be obtained and of the relevant position between the head and the surface to be printed, activating the nozzles or leaving them inactive.

Generally, in the event of the manufactured article to be decorated having reliefs, recesses or portions of surfaces differently inclined to each other, these are decorated at different times and with different devices to each other.

As can be easily guessed, this significantly complicates the decoration of this type of manufactured articles compared to the manufactured articles that have a flat surface to be decorated.

In order to overcome these drawbacks, decoration devices have been devised provided with adjustable heads, that is, with a variable inclination in order to adapt to the particular conformation of the manufactured article to be decorated and thus allow the complete decoration of the manufactured article itself in a single solution.

These devices do, however, also have some drawbacks, since they are designed to decorate “special” manufactured articles, i.e. provided with reliefs, recesses or surfaces differently inclined to each other, while they are not suitable or are characterized by a significantly lower production output in the case of “standard” manufactured articles, or the surface of which to be decorated is flat. As can be easily understood, this drawback makes the use of these machines inflexible and, therefore, expensive if compared to their production capacity. Description of the Invention

The main aim of the present invention is to devise a machine for the inkjet decoration of ceramic manufactured articles that allows decorating both manufactured articles having reliefs, recesses and/or surfaces differently inclined to each other and manufactured articles having a surface to be decorated of the flat type.

Within this aim, one object of the present invention is therefore to devise a machine that is of more flexible use than the machines of known type.

Another object of the present invention is to manufacture a machine that has higher production efficiency than the machines of known type.

Another aim of the present invention is to devise a machine for the inkjet decoration of ceramic manufactured articles that allows overcoming the aforementioned drawbacks of the prior art in the context of a simple, rational, easy, effective to use and affordable solution.

The aforementioned objects are achieved by the present machine for the inkjet decoration of ceramic manufactured articles according to claim 1.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more apparent from the description of a preferred, but not exclusive, embodiment of a machine for the inkjet decoration of ceramic manufactured articles, illustrated by way of an indicative, yet non-limiting example, in the accompanying tables of drawings wherein:

Figure 1 is an axonometric view of a machine according to the invention, in a first embodiment;

Figure 2 is a side elevation view of the machine in Figure 1 ;

Figure 3 is an axonometric view from below of the machine in Figure 1 ;

Figure 4 is a magnifying view of a part of the machine shown in Figure 3; Figure 5 is a cross-sectional view of the machine in Figure 1 with the swivel heads in neutral configuration;

Figure 6 is a cross-sectional view of the machine in Figure 1 with the swivel heads in special configuration;

Figure 7 is an axonometric view of a machine according to the invention, in a second embodiment;

Figure 8 is an axonometric view from below of the machine in Figure 7 ;

Figure 9 is a magnifying view of a part of the machine shown in Figure 8. Fmbodiments of the Invention

With particular reference to these figures, reference numeral 1 globally indicates a machine for the inkjet decoration of ceramic manufactured articles. The machine 1 comprises a basic frame 2, at least one supporting surface 3 of a ceramic manufactured article M having a surface to be decorated Ma, where the supporting surface 3 is associated with the basic frame 2 and is movable along a direction of forward movement 4.

More particularly, the basic frame 2 is only partly shown in the figures and is intended to be arranged to rest on a supporting surface, such as the ground.

The machine 1 comprises a plurality of printing heads 5,6 each provided with a plurality of nozzles 7 substantially aligned with each other along a relevant line of action 8 and adapted to dispense ink along a relevant direction of dispensing 9, each of said heads defining a respective range of action 10 on the surface to be decorated.

The direction of dispensing 9 is arranged transversely, and in particular perpendicularly, to the relevant line of action 8.

The nozzles 7 of each head 5,6 can be used either in whole or in part depending on the extent and shape of the surface to be decorated. The relevant range of action 10 may therefore differ from head to head.

The heads 5,6 comprise at least one fixed head 5, the line of action 8 of which is fixed and substantially parallel to the supporting surface 3, and at least one swivel head 6 with variable inclination between at least one neutral configuration, wherein the respective line of action 8 is substantially parallel to the supporting surface 3, and at least one special configuration, wherein the relevant line of action 8 is inclined with respect to the supporting surface 3.

More in detail, the machine 1 comprises a plurality of fixed heads 5 and a plurality of swivel heads 6.

Preferably, the swivel heads 6 are continuously movable, so that a wide variety of possible angles can be achieved.

It cannot however be ruled out that the swivel heads 6 can be moved discretely, i.e., at predefined angular intervals.

Suitably, the swivel heads 6 are movable along an angular range ranging from 0° to 90°.

According to the invention, the machine 1 comprises a plurality of groups 11 of heads 5,6, where each of such groups 11 comprises a plurality of rows 12 of heads 5,6 arranged parallel to each other along a direction transverse to the direction of forward movement 4.

The heads 5,6 of each row 12 are staggered with respect to the heads 5,6 of the adjacent row 12 belonging to the same group 11 so that their ranges of action 10 involve the entire width of the surface to be decorated Ma, transversely to the direction of forward movement 4, when the swivel heads 6 are in a neutral configuration, while the ranges of action of the heads 5,6 only partly cover the width of the surface to be decorated Ma, transversely to the direction of forward movement 4, when the said swivel heads 6 are arranged in a special configuration.

Each head 5,6 has two end nozzles 7a arranged along the relevant line of action

8.

Advantageously, when the swivel heads 6 are in neutral configuration, the lines of action 8 of the heads 5, 6 belonging to each of the rows 12 are substantially aligned to each other and the distance between the end nozzles 7a of the heads 5,6 of each of the rows 12 and the end nozzles 7a of the consecutive heads 5,6, belonging to the adjacent row 12 of the same group 11, is substantially equal to the distance between two nozzles 7 belonging to the same head 5,6.

In this way, the end of the range of action 10 of a head 5,6 corresponds to the beginning of the range of action 10 of the next head 5,6 arranged in the adjacent row of the same group 11 of heads 5,6.

Preferably, when the swivel heads 6 are in neutral configuration, the nozzles 7 belonging to different rows 12 are aligned with each other, by alternating rows 12, along a direction of alignment 13 which is transverse to the relevant lines of action 8.

Conveniently, the direction of alignment 13 is substantially parallel to the direction of forward movement 4.

In more detail, each of the groups 11 of heads 5,6 is adapted to dispense a corresponding color of ink. In the embodiments shown in the figures, each group 11 comprises two rows 12 of heads 5,6.

More particularly, the machine 1 comprises at least one supporting plate 14 of the heads 5,6 associated with the basic frame 2 and positioned above the supporting surface 3. The supporting plate 14 comprises at least one fixed portion 14a supporting the fixed heads 5 and at least one movable portion 14b supporting the swivel heads 6 and movable in rotation around a relevant axis with respect to the basic frame 2.

Advantageously, the machine 1 comprises actuation means 15 of the displacement of the movable portion 14b.

More particularly, the actuation means 15 comprise at least one actuation element, of the type of a fluid- operated cylinder, associated with the movable portion 14b. In the embodiment shown in the figures, the fluid- operated cylinder 15 has a body associated with the basic frame 2 and a piston, movable in a sliding manner with respect to the body, associated with the movable portion 14b.

In an embodiment, not shown in the figures, the swivel heads 6 are movable independently to each other between the neutral configuration and the special configuration. In other words, each swivel head 6 can be moved independently of the other swivel heads 6, in such a way that each of the swivel heads 6 can be arranged in the most suitable position depending on the conformation of the manufactured article M to be decorated. In the embodiment shown in Figures 1 to 6, on the other end, at least some of the swivel heads 6 are movable locked together between the neutral configuration and the special configuration.

More particularly, in the embodiment shown in the figures, the swivel heads 6 correspond to one of the end heads of at least one of the rows 12 of each of the groups 11 of heads 5,6.

Conveniently, the movable portion 14b of the supporting plate 14 supports the swivel heads 6 locked to each other and the actuation means 15 comprise a single actuation element adapted to move the movable portion 14b.

In the second embodiment shown in Figures 7 to 9, the movable portion 14b comprises at least a first movable portion 14b’, supporting the swivel heads 6 locked to each other which are arranged at one end of at least one of the rows 12 of each of the groups 11 of heads 5,6, and at least a second movable portion 14b”, supporting the swivel heads 6 locked to each other which are arranged at the other end of the same row 12 of each of the groups 11 of heads 5,6. Preferably, the first movable portion 14b’ and the second movable portion 14b” are movable independently of each other.

In this embodiment, the actuation means 15 comprise two actuation elements, arranged on opposite sides of the supporting plate 14 and each adapted to move a relevant movable portion 14b’, 14b”.

In more detail, the actuation elements 15 are arranged on opposite sides with respect to a median plane of the supporting plate 14 passing through the direction of forward movement 4.

The operation of the present invention is as follows.

Depending on the manufactured article M to be decorated, the swivel heads 6 are moved to the special configuration, in such a way as to arrange the relevant lines of action 8 in a manner that is almost parallel to the average inclination line of the transverse profile of the portion of the surface to be decorated Ma subjected to the range of action 10 of the head itself. In particular, said average inclination is identified by the chord joining the two end points of the profile of the concerned portion of the surface to be decorated Ma. One example may be the decoration of the so-called “skirting boards”, which have a main substantially flat portion and a portion inclined with respect to such main portion.

In the event of the manufactured article M having both lateral edges, opposite each other, and inclined with respect to the upper surface to be decorated Ma, it is possible to use the machine 1 shown in Figures 7 to 9 and move the two movable portions 14b’ and 14b” independently of each other so as to move the relevant swivel heads 6 to the special configuration most suitable for the decoration thereof.

If, on the other hand, “standard” type manufactured articles M are also fed onto the conveying surface, i.e., the surface of which to be decorated Ma is substantially flat and devoid of reliefs, recesses or differently inclined portions, the swivel heads 6 are brought back, or kept, in neutral position, so that their range of actions 10 are able to cover the entire width of the surface to be decorated Ma.

It has in practice been ascertained that the described invention achieves the intended objects and, in particular, the fact has been underlined that the machine to which the present invention relates, allows adapting in a flexible manner to the production requirements, thus optimizing the decorative process both in case of “special” manufactured articles, i.e. provided with reliefs, recesses or differently inclined surfaces, and of “standard” manufactured articles, i.e. the surface of which to be decorated is flat.

This is due to the special arrangement of the heads, both swivel and fixed, which allows the largest possible printing area to be covered when the swivel heads are in the neutral position.