CARTRIDGE FOR AIRBRUSHES

DESCRIPTION

Field of the invention

The present invention relates to the technical field of devices that are used for both professional and hobby use, for painting surfaces of different type, and in particular relates to a paint cartridge for airbrush that can be used both for airbrushes having a connection for the cartridge at the upper part, and for airbrushes having a connection for the cartridge at the lower part.

Description of the prior art.

As known spray painting is a very commonly used technique for both professional and hobby use for painting a surface avoiding a direct contact with the same, as, instead, happens in the case of painting with paintbrushes .

Among the tools used for spray painting, it is suitable to mention the so-called spray cans that are nowadays widespread for their availability and simplicity to be used. However, the spray cans have the drawback of being very expensive if compared to the surface that can be painted. As known, the spray cans essentially provide a container, commonly made of aluminium, inside of which are contained the paint, and a propellant, generally propane, or butane, or isobutane, that is a gas compressed until it turns to liquid state. However, the quality of spray painting reached by using the common spray cans is very low, therefore for applications requiring a medium-high quality other spray painting tools, which are able to guarantee better results, are preferred. Among the tools most appreciated by the painters for both professional and hobby use, there are the spray paint guns, also called airbrushes that are used for spraying various type of paints by a process of nebulization carried out by using compressed air.

More precisely, an airbrush essentially comprises a main body, or "gun", having a handle in order to be grasped by a user and, therefore, to be moved with respect to the object to be painted, in order to direct nebulized paint jet. At the handle, the airbrush, usually, provides a connection for connecting the duct feeding the compressed air produced by a compressor to a pneumatic circuit made in the main body of the airbrush. The paint passes from a container, or "glass", which is integral to the main body of the airbrush, in which, at the beginning, the paint is contained, to a hydraulic circuit, which is, also this, made in the main body of the airbrush, but that does not communicate with the aforementioned pneumatic circuit of the compressed air. In the airbrushes having the container of paint at the upper part of the main body, the paint passes by gravity in the aforementioned hydraulic circuit, whilst in the airbrushes having the connection for the paint container at the lower part of the main body, the paint is sucked from the bottom of the container by a suction duct. When the paint is supplied on the object to be painted, the user acts on an actuation lever of which the airbrush is provided of, in such a way to cause a needle, which opens and closes the supply nozzle, to move backward. In this way, the needle moves from a closing position to an opening position of the supply nozzle and allows, therefore, the paint to pass through the supply nozzle. Laterally to the paint supply nozzle apertures are, furthermore, provided through which the compressed air is supplied to nebulize the paint close to the aforementioned supply nozzle and, thus, to supply a nebulized paint jet, which is directed towards the object to be painted by the airbrush.

The aforementioned container of paint is usually integrated into the airbrush body. Only in few airbrushes with hanged containers, the container of paint is of removable type. In this case, the container and the main body of the airbrush provide elements of removable mutual engagement, in such a way that is possible to engage the container of paint to the airbrush, and removed the same once the paint is finished.

However, nowadays, the use of high pressure airbrushes is limited to few expert users, for different reasons, one of which is that the use of paints and diluents need to have a good knowledge on the paint chemistry, that not everyone has. Furthermore, the use of airbrush is not always advantageous, in particular for small works, this because a preparation procedure is necessary for measuring the amount of paint to be used, for choosing the specific diluent, as well as for mixing the two components in the correct ratio. In addition to the above, once the paint work is finished, it is, furthermore, necessary to carry out a procedure for cleaning the airbrush and, in particular, of the glass, i.e. the container containing the paint, considerable waste of time, of paint, and consumption of diluent necessary to carry out the aforementioned cleaning procedure.

Examples of cartridges for airbrush of prior art having the above disclosed drawbacks are, for example, described in US2011/114749, US2013/105598, US2017/239679 and DE3517122.

Summary of the invention

It is therefore an object of the present invention to provide a paint cartridge for airbrush that is able to overcome the aforementioned drawbacks.

It is in particular an object of the present invention to provide such a paint cartridge for airbrush that is universal, because can be engaged both to airbrushes with the connection for the paint cartridge at the upper part, and to airbrushes with the connection at the lower part.

It is also an object of the present invention to provide such a paint cartridge for airbrush that is able to protect the paint remaining within the cartridge at the end of a painting operation.

These and other objects are achieved by a paint cartridge for airbrush, according to the invention, comprising :

- a containment body having a lateral wall and a bottom delimiting a containment chamber arranged to contain a predetermined initial volume of paint;

- a communication portion provided with: a first communication mouth associated to a first communication duct having a first length li and configured to protrude into said containment chamber; and

- a second communication mouth;

- an engagement portion providing a first and a second passage and configured to reversibly move between a disengagement configuration, in which said containment body is disengaged from an airbrush, and an engagement configuration, in which said engagement portion is arranged to engage said communication portion of the cartridge and said airbrush, in said engagement configuration said first passage being in communication with said containment chamber through one between said first and said second communication mouth to put said containment chamber in communication with the external environment and allow to introduce the compensation air within the same, and said second passage being in hydraulic communication with said containment chamber through the other communication mouth in order to allow said paint exiting said containment chamber to enter a hydraulic circuit provided in said airbrush;

whose main characteristic is that said first and said second communication mouth are, respectively, associated to a first and to a second closing/opening device, each of which configured to move between a closing position, in which is arranged to close a respective communication mouth, and an opening position, in which is arranged to open said respective communication mouth, said first and said second closing/opening device being configured in such a way that said movement from said closing position to said opening position is caused by the movement of said engagement portion from said disengagement configuration to said engagement configuration.

The solution provided by the present invention allows, in particular, to have the advantage that, once the work is finished, the cartridges, which are not finished, can be preserved also for a long time, because, once they are disengaged from the engagement portion, for example by a ring nut, the closing/opening devices guarantee a perfect closure of the cartridge, thus preserving the product for much more time than a paint can provided with a pressure cap of traditional type.

Further features and related embodiments of the invention are set out in the dependent claims.

In particular, the engagement portion can comprise:

- first engagement members configured to removably engage the engagement portion and the communication portion; and

- second engagement members configured to removably engage the engagement portion and an airbrush.

In particular, each actuation element can be a push member integral to said engagement portion.

Advantageously, each said first and second push member is a hollow member, and provides, respectively a first and a second opening in such a way that, after having caused the aforementioned movement from the closing position to the opening position of said first and second closing/opening device, is arranged to put the duct to which is associated to, in communication with the external environment, or to said hydraulic circuit of the airbrush for feeding the paint.

According to another aspect of the invention, a system for supplying paint comprises:

- a paint cartridge for airbrush as described above;

- an airbrush arranged, in use, to be operatively connected to a compressed air feeding device, said airbrush being provided of a connection portion configured to removably engage the aforementioned engagement portion of the cartridge.

In particular, the system for supplying paint can comprise :

- a paint cartridge for airbrush as described above;

- a first engagement portion comprising a first and a second actuation element, in cui said first actuation element is arranged at a first distance dl' from the aforementioned engagement axis equal to said first distance dl and arranged to operate, in use, the movement of said first closing/opening device from the closing position to the opening position, and said second actuation element is arranged at a second distance d2' from the engagement axis equal to said second distance d2, and is arranged to operate, in use, the movement of said second closing/opening device from the closing position to the opening position;

- a second engagement portion comprising a first and a second actuation element, in which said first actuation element is arranged at said second distance d2' from the engagement axis and is arranged, in use, to operate the movement of said second closing/opening device from the closing position to the opening position, and said second actuation element is arranged at said first distance dl' from said engagement axis and is arranged, in use, to operate the movement of said first closing/opening device from the closing position to the opening position;

- an airbrush arranged, in use, to be operatively connected to a compressed air feeding device, said airbrush being provided with a connection portion configured to removably engage the aforementioned engagement portion of the cartridge.

Brief description of the drawings

The invention will now be shown with the following description of its exemplary embodiments, exemplifying but not limitative, with reference to the attached drawings in which :

Fig. 1A diagrammatically shows a side elevational view partially sectioned of a first embodiment of a paint cartridge for airbrush, according to the invention;

Fig. IB diagrammatically shows a side elevational view partially sectioned of a first embodiment of an airbrush to which the paint cartridge for airbrush of figure 1A can be engaged;

Fig. 1C shows an enlargement of the closing/opening devices of which the cartridge of figure 1A is provided of, in the closing position, in order to highlight some technical characteristics;

Fig. ID diagrammatically shows a longitudinal section view of one of the different supply heads of which the airbrush of figure IB can be provided of, in a closing position;

Fig. 2A diagrammatically shows, side elevational view partially sectioned, the paint cartridge of figure 1A in an engagement configuration with respect to the supply device of figure 1A;

Fig. 2B diagrammatically shows a longitudinal section view the supply head of figure ID in an opening position;

Fig. 2C shows an enlargement of the closing/opening devices of cartridge in an opening configuration;

Fig. 3A diagrammatically shows the cartridge, according to the invention, in a side elevational perspective view partially sectioned, in order to highlight some technical characteristics;

Fig. 3B shows an enlargement of a possible embodiment of an actuation element of which the engagement portion, according to the invention, can be provided of;

Fig. 3C shows an enlargement of a possible embodiment of the second communication duct of cartridge of figure 3A;

Fig. 4A diagrammatically shows a side elevational view partially sectioned of the cartridge of figure 1A engaged to an airbrush of different type from the one of figure IB and in a rest configuration;

Fig. 4B diagrammatically shows a longitudinal section view of one of the different supply heads of which the airbrush of figure 4A can be provided of, in a closing position;

Fig. 5A diagrammatically shows a side elevational view partially sectioned of the cartridge engaged to the airbrush of figure 4A, but in a working configuration;

Fig. 5B diagrammatically shows a longitudinal section view of the supply head of the airbrush of figure 5A in an opening position;

Fig. 5C diagrammatically shows an enlargement of the closing/opening devices of cartridge of figure 5A in order to highlight some functional aspects;

Figures 6A and 6B diagrammatically show, respectively, in an opening position and in a closing position, an enlargement of an alternative embodiment of the closing/opening devices shown in the figures 1C and 2C, ;

Fig. 7 diagrammatically shows a perspective view of a possible embodiment of the cartridge, according to the invention;

Fig. 8A and 8B diagrammatically show in exploded perspective views, two possible alternative embodiments provided for the engagement portion of cartridge ;

Figures 9A and 9B diagrammatically show, respectively the engagement portion of figure 8a and the engagement portion of figure 8B assembled to the cartridge of figure 7;

Fig. 10 diagrammatically shows a side elevational view partially sectioned of a possible alternative embodiment of the airbrush of figures IB and 4A according to the invention;

Fig. 11 diagrammatically shows a perspective view of a further alternative embodiment of the paint cartridge according to the invention;

Figures 12A and 12B show, respectively, a side elevational perspective view, and a side elevational view, of a further embodiment of the paint cartridge according to the invention;

Figures 13A and 13B diagrammatically show axial section views of the cartridge of figure 12A and 12B, respectively, in the disengagement configuration and in the engagement configuration;

Figures 14A and 14B show, respectively, a side elevational perspective view, and a side elevational view, of still a further embodiment of the paint cartridge according to the invention;

Figures 15A and 15B diagrammatically show axial section view of the cartridge of figure 14A and 14B, respectively, in the disengagement configuration and in the engagement configuration.

Detailed description of some exemplary embodiments of the invention

In figure 1A, a cartridge 1, is diagrammatically shown, in particular containing paint, but also ink, or another painting substance, at the liquid state, according to the invention, destined to a spray gun, or airbrush 100. The cartridge 1 comprises, in particular, a containment body 10 having a lateral wall 11 and a bottom 12 delimiting a containment chamber 15 arranged to contain a predetermined initial volume of paint 55. In particular, the initial volume of paint 55 is such to leave a predetermined empty initial volume 56, i.e. that is not occupied by paint, within the containment chamber 15. At the side opposite to the bottom 12, the cartridge 1 comprises a communication portion 20 having a first communication mouth 21 and a second communication mouth 22. In particular, the first communication mouth 21 is associated to a first communication duct 23 having a first length I . More in particular, the first length li can be substantially equal to the length L of cartridge 1. Therefore, the first communication duct 23 can protrude into the containment chamber 15, from the first communication mouth 21 substantially up to the bottom 12 of containment body 10. In a provided embodiment of the invention, the second communication mouth 22 can be associated to a second communication duct 24. This can be configured to protrude into the containment chamber 15, starting from the second communication mouth 22, for a second predetermined length 1 ₂ . Advantageously, the second predetermined length is less than the first predetermined length li, i.e. 1 ₂ < li- In a possible embodiment of the invention, the length 1 ₂ of the second duct 24 can be shorter than, or substantially equal to, the thickness of the communication portion 20. In particular, each duct 23, or 24 provides at least an inlet aperture at a first end and at least an outlet aperture at the opposite end.

Advantageously, the cartridge 1, furthermore, comprises an engagement portion 120 configured to reversibly move between a disengagement configuration, in which the containment body 10 is disengaged from the airbrush, 100, and an engagement configuration, in which the engagement portion 120 is arranged to engage the containment body 10 to the aforementioned airbrush 100. More precisely, the engagement portion 120 provides a first and a second passage 121 and 122. When the engagement portion 120 is arranged in the engagement configuration, the first passage 121 is in communication with the containment chamber 15 through one between the first and the second communication mouth 21, or 22, for connecting the containment chamber 15 with the external environment, and the second passage 122 is in hydraulic communication with the containment chamber 15 through the other communication mouth 22, or 21, in order to allow paint to exit the containment chamber 15 and to be fed into a hydraulic circuit 101 made in the main body 112 of the airbrush 100.

The cartridge 1, according to the invention, provides, furthermore, a first and a second closing/opening device 41, 42. Each of these is configured to move between a closing position, in which is arranged to close a respective communication mouth 21, 22, and an opening position, in which is arranged to open the respective communication mouth 21 and 22. More precisely, the first and the second closing/opening device 41 and 42, are configured in such a way that the movement from the closing position to the opening position is caused by the movement of the engagement portion 120 from the aforementioned disengagement configuration to the aforementioned engagement configuration. In the embodiment of the invention that is shown in figure 1A, the engagement portion 120 provides first engagement members 141 and 142 arranged to removably engage the engagement portion 120 to the communication portion 20 and, therefore, to the containment body 10 integral to the same, and second engagement members 126 arranged to engage the engagement portion 120 to a support portion of airbrush 100. More in particular, the first engagement members 141 and 142 can be arranged to engage, respectively, the communication mouths 21 and 22. In addition, or in alternative, the first engagement members can be provided at respective engagement surfaces 129 and 29. For example, the first engagement members can provide threaded surfaces 129 and 29 configured to provide a threaded connection between the engagement portion 120 and the communication portion 20 (figure 3A) .

As shown in detail in the figures ID, 2B, 4B and 5B, airbrush 100 can be provided with a supply head 105 having a supply nozzle 102 for supplying the paint, and at least an outlet 104 for supplying compressed air. In particular, the supply nozzle 102 of the supply head 105 is in communication with the passage 122 of the engagement portion 120 through a hydraulic circuit 101 made in the main body 112 of airbrush 100. More in particular, the hydraulic circuit runs between the connection portion 125 and the supply nozzle 102.

Instead, the, or each, outlet 104 of the compressed air, or another transport fluid, is in pneumatic communication with a compressed air production device, commonly a compressor, through a feeding device, i.e. a duct provided with a suitable connection, through a pneumatic circuit 103. This is made in the main body 112 of airbrush 100 and runs between an inlet 111, in communication with the aforementioned compressed air production device, and, usually, positioned at a handle portion 115, and the, or each, aforementioned outlet 104 of the compressed air of the main body 112 of airbrush 100.

As known, airbrush 100 provides a needle 107 movable from, or towards, the supply nozzle 102. More in detail, at the moment of spraying the paint on the object to be painted, the user acts on an activation element, for example an activation lever 110, to operate the supply of paint through nozzle 102. In particular, the activation element 110 is operatively connected to needle 107 in such a way to cause the same to move away from the nozzle 102, which was, up to that moment, completely closed by needle 107, and, thus, causing, a greater, or smaller, opening ( figure ID) .

In this way, the paint exits the hydraulic circuit 101 of airbrush 100, through the supply nozzle 102, and is, then, hit by a compressed air flow exiting a respective pneumatic circuit 103 made in the airbrush 100 through at least an outlet 104, in order to cause the same to be nebulized before hitting the surface to be painted. At this regard it is suitable to note that airbrush 100 can have only an outlet 104 arranged substantially coaxial to nozzle 102 of paint (figure ID), or many outlets 104, in particular additional outlets 104 further to the main outlet 104 that is coaxially arranged to paint nozzle 102. The additional outlets are positioned on lateral portions 108a and 108b of which the supply head 105 of airbrush 100 is provided of, and can be rotated by the user in order to shape the nebulized paint jet. More in detail, in the embodiment of figures 1A and 2A, the engagement portion 120 provides a first and a second actuation element 141 and 142 arranged, respectively, to cause the first and the second closing/opening device, 41 and 42, to move from the closing position to the opening position. Instead, in the alternative embodiment shown in the figures 4A and 5A, the first and the second actuation element 141 and 142 of the engagement portion 120 are arranged, respectively, to cause the first and the second closing/opening device 41 and 42 to move from the closing position to the opening position. This, in particular, is possible because the actuation elements 141 and 142 are preferably of the same type and, therefore, are able to indifferently actuate, depending on the type of airbrush that is used, the first, or the second closing/opening device 41 and 42, which are, also these, of the same type. In particular, the possibility is provided that the communication ducts 23 and 24 can have the same diameter. More in particular, the possibility is provided that the actuation elements 141 and 142 can have the same size, in particular the same diameter. In this way, the cartridge 1, according to the invention, can be engaged both to airbrushes 100 providing the connection at the lower part (figure 2A) , in this case, in use the containment body 10 is arranged above the airbrush 100, and to airbrushes 100 providing the connection in the upper part (figure 5A) , in this case, in use, the containment body 10 is arranged below airbrush 100. More in detail, when the cartridge 1 is engaged to airbrushes 100 of the first type, it operates in a first working configuration, in which the containment chamber 15, and, therefore, the first communication duct 23, if present, is in communication with the external environment through passage 121 for introducing the compensation air into the containment body 10, whilst the second communication duct 24 is dipped in the paint and feed the same into the hydraulic circuit 101 of airbrush 100 through passage 122 (figures 2A and 2C) . Instead, when the cartridge 1 is engaged to airbrushes 100 of the second type, it operates in a second working configuration, in which the first communication duct 23 "draws" the paint from the bottom 12 of cartridge 1 in order to feed it into the hydraulic circuit 101 of airbrush 100 through passage 122, whilst, the second duct 24 put the containment chamber 15 in communication with the external environment through passage 121 (figure 5A) .

In a possible embodiment of the invention, the second engagement members 126 can comprise a threaded shaft arranged to engage a threaded tubular surface 127 of support portion 125. Different solutions are, anyway, provided for the second engagement members, which can be configured in such a way to provide a bayonet, or snap, coupling with the respective engagement elements of which the support portion 125 is provided of. In this case, the movement of the first and of the second closing/opening device 41 and 42 from the closing position to the opening position is caused by the movement of the first engagement members 141 and 142 from a disengagement position to an engagement position in particular of the communication mouths 21 and 22.

In a preferred embodiment of the invention, the first and the second closing/opening device 41 and 42 are of the same type. More in particular, the mechanism for actuating the movement of the first closing/opening device 41 is equal to the mechanism for actuating the movement of the second closing/opening device 42. In particular, the engagement portion 120 provides a first and a second actuation element 141 and 142 configured to cause respectively, the first and the second closing/opening device 41 and 42 to move from the closing position to the opening position, when the engagement portion 120 moves from the disengagement position of figure 1A to the engagement position of figure 2A.

In a preferred embodiment of the invention, each of the first and the second closing/opening device 41 and 42 comprises, respectively, a first and a second obturator member 45 and 46 (see for example figure 1C) . In particular, both the obturator members 45 and 46 can be substantially spherical shaped (figures from 1A a 6B) , or substantially planar, case not shown in figure for simplicity. In a further alternative embodiment, diagrammatically shown in the figures 13A, 13B and 15, the first obturator member 45, i.e. the one of the first closing/opening device 41, can be spherical shaped, whilst the second obturator member 46, i.e. the one of the second closing/opening device 42, can have a shape substantially planar, for example such a flat washer. The obturator member 45, or 46, is arranged to reversibly move from a closing position to an opening position of the respective communication mouth 21 and 22. Still with reference to the example of figure 1C, each closing/opening device 41, or 42 can comprise, furthermore, a push member, for example a spring 47, or 48, configured to exert a predetermined thrust force, on a respective obturator member 45, or 46, in such a way to oppose the aforementioned movement of the respective obturator member 45, or 46, from the closing position to the opening position.

As shown, for example, in the figure 1A and 2A, the first and the second closing/opening device 41 and 42 can be configured to be housed partially or completely, respectively, in the first and in the second duct 23 and 24. In this case, each push member 47, or 48, can be housed within the respective communication duct 23, or 24.

In the alternative embodiment shown in the figures 1C and 2C, the first and the second duct 23 and 24 can provide, going from the first and from the second communication mouth 21, and 22 towards the containment chamber 15 of the containment body 10, respectively, a first portion 23a and 24a, having a first cross section SI, and a second portion 23b and 24b, having a second cross section S2, with S1<S2. In particular, the cross section SI is smaller than the greatest size, in particular the diameter, of the sphere of the obturator member 45, or 46. Therefore, each communication duct 23 and 24 provides a "narrow passage", which limits the stroke of obturator member 45, 46 towards the respective communication mouth 21, 22, thus avoiding that the same can exit the cartridge 1 through the respective communication mouth 21, 22.

According to the invention, the aforementioned narrow passage, which limits the stroke of the obturator members 45 and 46, can be made at the portion of the communication ducts 23 and 24 of communication portion 20, as shown, for example in figure 2C, or can be obtained for a different cross section between the portion of communication ducts 23 and 24 arranged at the containment body 10, and the portion, which passes through the communication portion 20, case not shown in figure for reasons of simplicity. In this latter case, the actuation elements have a length higher than the section of communication portion 20.

In the preferred embodiment of the invention that is shown in detail in the figures 2C and 5C, the first and the second actuation element 141 and 142 provide, respectively, a first and a second push member, which is preferable hollow, integral to the engagement portion 120. More in detail, each push member 141 and 142 can be arranged to engage, in use, a respective duct 23, or 24, of cartridge 1, depending on this has to engage an airbrush 100 with a connection in the upper part, or in the lower part. In particular, when the engagement portion 120 is arranged in the engagement configuration, each push member 141 and 142 is arranged to push on a respective obturator member 45, or 46, exceeding the elastic force of the respective spring 47, or 48, in such a way to cause the same to move backward within the duct 23, or 24. In this way, it is possible to put the containment chamber 15 in communication with the external environment and with the hydraulic circuit 101 of airbrush 100, respectively, in the case the cartridge 1 is engaged to an airbrush 100 of the type of figure IB, or, through the communication mouths 22 and 21, in the case the cartridge 1 is engaged to an airbrush 100 of the type of figure 5B. More in particular, in each push member 141, 142 a respective passage 121 and 122 is made. For example, as diagrammatically shown in figure 3B, each push member 141, or 142, at least at the end portion, provides a bevelled surface formed by protruding portions 147 and recessed portions 148 alternated to each other, in such a way to define the aforementioned apertures, or slits, 143 and 144.

As shown, in particular in figure 2C, between the engagement portion 120 and the communication portion 20, sealing elements 145, for example O-ring, can be provided arranged to guarantee hydraulic/pneumatic sealing conditions between the two parts.

In a possible embodiment, the engagement portion 120 and the communication portion 20 can provide elements of mutual engagement of "snap", or bayonet, type. In addition, or in alternative, to the snap, or bayonet, engagement elements 141, 142 and 21, 22, a tightening element 130 can be provided, arranged to firmly engage the engagement portion 120 to the communication portion 20 and, therefore, to guarantee that these remain in position during the use of airbrush 100, once arranged in the engagement configuration. For example, the tightening element 130 can be a tightening ring nut, which is mounted externally to the engagement portion 120 and to the communication portion 20. In particular, the tightening ring nut 130 provides an internal threaded surface 131 arranged to provide, in use, a threaded connection with the external surface of at least one between the engagement portion 120 and the communication portion 20.

According to another aspect of the invention, shown in detail in figure 3C, the lateral surface 28 of second communication duct 24 can have a series of lateral apertures 28a in such a way to provide a substantially "an open cage", or "reticular", structure. In this way, the communication duct 24 is able, for all its length 1 ₂ , to put the containment chamber 15 in communication with the hydraulic circuit 102 of airbrush 100, in order that the paint completely exits, in the case of figure 2A, or to introduce within the same the compensation air from the external environment, in the case of figure 5A, and therefore, to guarantee that all the paint contained in the cartridge 1 can be used, in ideal safety conditions for the user.

In an alternative embodiment diagrammatically shown in the figures 6A and 6B, respectively in a closing position (figure 6A) , and in an opening position (figure 6B) of the communication mouths 21 and 22, the aforementioned section narrowing of duct 23 and 24 is, instead, obtained by a stop element 25, or 26, which protrudes from the surface of duct 23 and 24 towards the inside of the same duct.

In the preferred embodiment diagrammatically shown in the plan view of figure 7, the first and the second communication mouth 21 and 22 are, advantageously, made at the same diameter, but in eccentric positions with respect to the communication portion 20. More precisely, in order to move from the disengagement configuration to the engagement configuration, the engagement portion 120 and the communication portion 20 are arranged to translate along a predetermined engagement axis 27 one with respect to the other. In particular, the aforementioned communication mouths 21 and 22 can be provided on the communication portion 20, respectively at a first distance dl, and at a second distance d2, with dl¹d2 from the aforementioned engagement axis 27, for example coincident with geometric axis of the communication portion 20. In this way, the engagement portion 120 can engage the containment body 10 of cartridge 1 only if it is positioned with a predetermined orientation with respect to the same. Therefore, it is avoided that the user can erroneously position the cartridge 1 with respect to the airbrush 100. More precisely, 2 different engagement portions 120a and 120b can be provided depending on that the cartridge 1 has to engage an airbrush of the type of figure IB, or an airbrush of the type of figure 4A. In particular, in both the cases, the engagement portion 120a, or 120b, comprises a first and a second actuation element 141 and 142. However, in the first case the first actuation element 141 is arranged at a first distance dl' from the engagement axis 27 that is equal to distance dl, and is arranged, in use, to operate the movement of the first closing/opening device 41 to move from the closing position to the opening position, whilst the second actuation element 142a is arranged at a second distance d2' from the engagement axis 27 that is equal to distance d2, and is arranged, in use, to operate the movement of the second closing/opening device 42 from the closing position to the opening position (figures 8A and 9A) . Instead, in the second case, the first actuation element 141 is arranged at a first distance dl' from the engagement axis 27 that is equal to the second distance d2 and is arranged, in use, to operate the movement of the second closing/opening device from the closing position to the opening position, and instead the second actuation element 142 is arranged at a second distance d2' from the engagement axis 27 that is equal to the first distance dl, and is arranged, in use, to operate the movement of the first closing/opening device 41 from the closing position to the opening position (figures 8B and 9B) .

In a further alternative embodiment of the invention, not shown in the figures for simplicity, the cartridge 1 can, furthermore, provide reference elements arranged to provide a "matching", i.e. a coupling, only in a predetermined relative position between the cartridge and the engagement portion. In addition, or in alternative, identification symbols can be provided in proximity to the respective communication mouths 21 and 22, in such a way that it is possible to univocally identify the communication mouth 21, i.e. the one associated to duct 23 of length l _lf and the communication mouth 22, i.e. the one associated to duct 24 of length 12 with l ₂ «li.

According to another aspect of the invention, a system 200 for supplying paint comprises a spray gun, or airbrush, 100 arranged, in use, to be operatively connected to a compressed air production device, usually a compressor, not shown in figure for reasons of simplicity, but anyway of known type, and a paint cartridge 1, as above described with reference to figures from 1A to 9B .

The system 200 can comprise both a first engagement portion 120a and a second engagement portion 120b as described above. In this way, the kit so obtained can be used, from time to time, in order to engage the cartridge 1 to airbrushes 100 of the type shown in figure 1A, or to airbrushes of the type shown in figure 4A.

According to still another aspect of the invention, as diagrammatically shown in figure 10, the engagement portion 120 provided of the aforementioned actuation devices 141 and 142, which actuate the movement of the closing/opening devices 41 and 42 of cartridge 1 can be provided integrated into the airbrush 100 shown in figure 10.

In a possible alternative embodiment diagrammatically shown in figure 11 the communication portion 20 provided of the closing/opening devices 41 and 42, and of the ducts 21 and 22, can be of removable type. More precisely, the communication portion 20 can be a stand alone component with respect to the containment body 10 of cartridge 1. In this case, the communication portion 20 and the containment body 10 of cartridge 1 can be provided of mutual coupling elements configured to provide a removable connection of the two components. In particular, the containment body 10 of cartridge 1 can have an engagement mouth 13 configured to engage the aforementioned communication portion 20, for example by a threaded connection. More precisely, in the example of figure 11, the lateral surface 14 of the engagement mouth 13 can be threaded and be arranged to engage a respective threaded surface 29 of the communication portion 20. This is however provided with the aforementioned elements of mutual engagement, which allow the engagement to the aforementioned engagement portion 120. Notwithstanding, as an example, reference has been made to a threaded connection, the possibility is also provided that the body 10 of cartridge 1 and the communication portion 20 can be provided of mutual coupling elements configured to provide a bayonet coupling, a snap coupling, or another coupling of removable type.

With respect to the embodiments of cartridge 1 described above, according to the invention, with reference to the figures from 1 to 10, which are, advantageously, intended to be sold containing a predetermined amount of paint and, in particular, as "disposable" product, the alternative embodiment shown in figure 11 allows, instead, to provide a cartridge 1 that can be sold empty and with the "valve group" comprising the closing/opening devices 41 and 42, separated from it, because integral to the communication portion 20. Furthermore, for this embodiment, the cartridges could be provided empty, in such a way that they can be used by paint shops equipped with tintometers for selling paints on demand, or used, even several times, by the expert user, who can prepare specific customized mixture of colours and, then, preserve the same for following retouching.

In the figures from 12A to 15B further embodiments according to the invention are shown. More precisely, both in the embodiment of the figures from 12A to 13B and in the embodiments of the figures from 14A to 15B, the first communication mouth 21 and the second communication mouth 22 of communication portion 20 are arranged coaxially one with respect to the other. Also the respective closing/opening devices 41 and 42 are configured in such a way to be arranged coaxially one with respect to the other. More in detail, as diagrammatically shown both in the embodiment shown in the figures from 12A to 13B and that refer to the case in which the cartridge 1 is engaged below the airbrush 100, analogously to what has been described with reference to figure 5A, and in the embodiment shown in the figures from 14A to 15B, which, instead, refers to the case in which the cartridge 1 is engaged above the airbrush 100, analogously to what described with reference to figure 2A, the first communication mouth 21 of communication portion 20 can be arranged axially to cartridge 1, and the second communication mouth 22, in particular substantially annular-shaped, can be arranged around the first communication mouth 21. In particular, the first closing/opening device 41 can provide an obturator member 45, for example of spherical shape, and a push member 47 arranged to oppose the movement of the closing/opening device 41 from the closing position of figure 13A and 15A to the opening position of figure 13B and 15B. Analogously, the closing/opening device 42 provides an obturator member 46, advantageously of flattening shape, for example substantially annular-shaped, and a respective push member 48 arranged to oppose the movement of the closing/opening device 41 from the closing position of figure 13A and 15A to the opening position of figure 13B and 15B. More in particular, the second push member 48 can be arranged externally to the closing/opening device 41, advantageously coaxially to the first push member 47. More precisely, the second push member 48 can be contained between the second obturator member 46 and a shoulder, or protruding portion 49 of the containment portion of the first closing/opening device 41, for example the end portion of the communication duct 23 if present. In particular, the protruding portion 49 can be a support surface of a support body 43 running from the communication portion 20 to the duct 23. More in particular, the support body 43 provides one, or more holes, in order to allow the paint to exit cartridge 1 (figure 13B) , or the compensation air to enter the cartridge 1 (figure 15B) . For example, the support body 43 can have a substantially reticular geometry, advantageously can be substantially "cage-shaped".

The second obturator member 46 can be provided with sealing elements, solution not shown for simplicity. In addition, or in alternative, the sealing elements 44 can be integral to the containment body 10 near the second communication mouth 22, solution not shown for simplicity. More in detail, in the embodiment of the figures from 12A a 13B, in the engagement configuration of the communication portion 20 and of the engagement portion 120, for example by threaded connection (figure 13B) , the closing/opening device 41 is arranged in the opening position and puts, therefore, the containment chamber 15 in communication with the outside. Therefore, the compensation air can enter into the containment chamber 15 after having crossed the engagement portion 120 through passage 122, and the communication portion 20 through the first communication mouth 21. The paint, instead, passes in the communication portion 20 through the second communication mouth 22 and from here in the circuit of the airbrush 100 through passage 121 of engagement portion 120.

In the embodiment shown in the figures from 14A to 15B, in the engagement configuration of the communication portion 20 and of the engagement portion 120 (figure 15B) , the closing/opening device 41 is arranged in the opening position and, therefore, allows the paint exiting the containment chamber 15 of containment body 10 to enter the circuit of the airbrush 100. Instead, the compensation air enters the engagement portion 120 through passage 122 and, then, passes in the communication portion 20 through the second communication mouth 22 and from here in the containment chamber 15. In particular, the passage 122 of the engagement portion 120 can be coaxial to passage 121 (figures 15A and 15B) , or substantially orthogonal to the same (figures 13A and 13B) . As diagrammatically shown in the figures 13B and 15B, at least a sealing element 128, for example an O-ring, is advantageously, furthermore, provided, arranged to guarantee the necessary sealing conditions between the engagement portion 120 and the communication portion 20.

The foregoing description exemplary embodiments of the invention will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt for various applications such embodiment without further research and without parting from the invention, and, accordingly, it is therefore to be understood that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realize the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation .