IT202100008606A1 - DEVICE FOR GLAZING MANUFACTURED PRODUCTS AND RELATED PLANT - Google Patents

Description

DESCRIPTION

of the Italian Patent for Industrial Invention entitled:

?DEVICE FOR GLAZING ARTIFACTS

AND RELATED INSTALLATION?

TECHNICAL FIELD

The present invention relates to a device for glazing articles, in particular ceramic articles, and a related plant.

PRE-EXISTING TECHNIQUE

In the ceramic field, various methods are known for the application of glaze on ceramic artefacts.

A first known method provides for the use of a device, known in the jargon as a "bell", which allows the formation of a film of glaze under which the product is passed.

A drawback of this first known methodology consists in the difficulty to apply the enamel evenly on the artifact, in fact, the quantity? of applied enamel is greater at the edges of the artefact and less in the central area.

Furthermore, in order to cover the entire surface of the manufactured article, the film defined by the bell must have a greater extension than the manufactured article itself, which involves a huge waste of material and a large volume of the bell. A second known method, known in the jargon as "airless", provides for the application of the enamel by nebulization.

Also this methodology presents for? some drawbacks, such as a high waste of material which remains suspended inside the relative container, and the fact that, in particular for medium-large sized articles, it is difficult to apply the glaze uniformly on the surface to be covered.

An object of the present invention ? that of overcoming the aforementioned drawbacks of the prior art, within the ambit of a simple, rational and low-cost solution.

These purposes are achieved by the characteristics of the invention set forth in the independent claims. The dependent claims outline preferred and/or particularly advantageous aspects of the invention.

EXHIBITION OF THE INVENTION

The invention, in particular, makes available a device for glazing manufactured articles which comprises:

a box container in which ? contains an enamel for glazing manufactured articles, in which the box-like container comprises a bottom wall equipped with at least one passage opening elongated along a horizontal longitudinal axis and configured to let out a veil of glaze into which the passage opening is made up of a plurality of through holes arranged in a single row and aligned along a horizontal alignment direction parallel to the longitudinal axis and orthogonal to a reciprocal movement direction between the articles and the box-like container.

According to the invention, each through hole ? formed by a respective delivery nozzle fixed to the back wall.

Thanks to this solution, ? made available a simple and functional, compact and effective device capable of allowing the application of enamel on the artefacts in a homogeneous way.

Basically, each dispensing nozzle allows a controlled and precise dispensing of glaze and the set of dispensing nozzles defines a homogeneous veil of glaze which determines an effective and homogeneous glazing of the articles.

Advantageously, each dispensing nozzle can comprising an elongated tubular body provided with a longitudinal axis orthogonal to the direction of movement and to the longitudinal axis of the passage opening, wherein the tubular body preferably protrudes below the bottom wall by at least one axial section.

Furthermore, the tubular body of each dispensing nozzle can have a length substantially between 30 mm and 60 mm, preferably equal to 50 mm ? 55m and/or the axial portion protruding below the bottom wall of each tubular body can? have a length substantially between 10 mm and 20 mm, preferably equal to 15 mm ? 2mm.

Advantageously, each tubular body can present a circular and constant internal transversal section along the entire longitudinal development of the same, with an internal diameter substantially equal to 0.8 mm ? 0.1mm.

Again, are the through holes of the row of through holes (ie the dispensing nozzles) equidistant from each other, preferably with a pitch substantially equal to 5 mm? 1 mm (i.e. between 4 mm and 6 mm).

In this way, said holes, suitable for dispensing a relative strip (or a relative jet) of glaze on the article, are spaced apart from each other so that the contiguous strips (or contiguous jets) join together to define a layer (or veil) of substantially homogeneous enamel, guaranteeing an optimal aesthetic result of the product.

In particular, one aspect of the invention provides that the device can comprise a pressure control unit inside the box-shaped container configured to generate a depression inside the box-shaped container at a pressure value lower than an atmospheric pressure value for stop the glaze from coming out of the passage opening.

Thanks to the control group, the device can? operate as the product passes and according to its size, thus controlling the distribution of the glaze in order to minimize (or avoid) waste of material and/or drippings and unwanted dirt.

According to one aspect of the invention, said control group can include a vacuum generator.

Thereby, ? made available an element with a small footprint and low energy absorption, simple maintenance and ease of use. of assembly, designed to generate a suitable vacuum inside the box-like container.

An aspect of the invention also provides that the passage opening can be constituted by at least one elongated through slot arranged orthogonal to a reciprocal movement direction between the articles and the box-like container.

Thanks to this solution ? made available a passage opening shaped in such a way as to make it possible to dispense a homogeneous film of glaze on the artefacts.

In particular, the dispensing of a film of enamel from the passage opening thus? conformed, allows you to obtain quality products? and optimal aesthetic result. Alternatively, one aspect of the invention provides that the passage opening can consist of a plurality of of through holes arranged in a (single) row and aligned along a horizontal alignment direction parallel to the longitudinal axis and orthogonal to a reciprocal movement direction between the articles and the box-like container.

Thanks to this solution, ? possible to further minimize the waste of material, while guaranteeing a homogeneous film of glaze on the artefacts.

A further aspect of the invention also provides that the bottom wall of the device can be made of a plastic material, preferably polyurethane.

Thanks to this solution, the back wall of the device has excellent resistance/resilience to mechanical stress and good washability. surface which guarantees a high resistance to wear functional to maintaining the performance of the device itself and lengthens its useful life.

In particular, the back wall so? accomplished ? characterized by minimal deformations and/or wear phenomena in correspondence with the passage opening (for example due to the abrasive composition of the glaze) in correspondence with the passage opening, ensuring efficient distribution of the glaze for a high number of work cycles .

The dispensing nozzles can be made at least partially of metal, for example of steel.

One aspect of the invention provides that the bottom wall is associated with the box-like container in a removable manner.

Thereby, ? It is possible to replace the back wall of the container, minimizing the costs relating to the retooling of the device and guaranteeing constant efficiency over time.

A further aspect of the invention provides that the box-like container can comprise at least one openable wall adjacent to or opposite the bottom wall.

Thereby ? made available a container (at least partially) that is easy to clean, even inside, for example at each color change or as needed.

According to a further aspect of the invention, the device can comprising at least one dispensing unit configured to generate a positive pressure in the box-like container at at least one dispensing pressure value greater than atmospheric pressure to allow the forced release of glaze from the passage opening.

Thanks to the delivery group, the device can? operate check the distribution of the glaze, or rather its quantity? and/or dispensing pressure according to the degree of coverage desired.

Furthermore, thanks to the dispensing group, ? It is possible to dispense a continuous film of enamel dispensed at the optimal pressure, in order to obtain an optimal aesthetic result of the product.

Furthermore, one aspect of the invention provides that the dispensing unit can comprise a pressure regulator configured to vary the dispensing pressure value to regulate the flow of glaze leaving the passage opening.

Thanks to this solution, ? It is possible to adjust in a simple and practical way the quantity? of enamel to be dispensed, in order to obtain a product with a film of enamel more? or less opaque depending on the needs?.

For the same purposes set out above, a further aspect of the invention makes available a plant for glazing manufactured articles which comprises:

- a conveyor equipped with a support surface configured to support at least one article in support and equipped with a handling group for moving the article along a horizontal movement direction; - a device, in which the back wall of the box-like container is superimposed in plan on at least one section of the support plane and at a distance from it. According to one aspect of the invention, the box-like container can be movably mounted on a conveyor support frame.

Thanks to this solution, in case of non-operation? of the device and/or need? for replacing parts of the container and/or cleaning the container, the same can be easily disassembled and reassembled and/or orientated on said frame.

In particular, within this aspect of the invention, the plant can provide that the box-like container can slide with respect to the support frame along a sliding direction parallel to the longitudinal axis of the passage opening.

In this way, the assembly and disassembly operations of the container with respect to the frame are particularly simple and do not involve particular efforts for an operator who can easily slide said container onto the frame.

Again, as an alternative or in addition to the above, the box-like container can be associated in an oscillating manner with respect to the support frame, between a working position, in which the back wall is substantially horizontal, and a washing position, in which the back wall is inclined to the horizontal.

Thanks to this solution, ? Is it possible to carry out the cleaning and washing operations of the container itself effectively and without having to disassemble it from the frame, reducing downtime due to non-operation? of the system and at the same time facilitating said operations.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will become apparent from reading the following description provided by way of non-limiting example, with the aid of the figures illustrated in the attached tables.

Figure 1 ? a schematic view illustrating the main components of the plant according to the invention.

Figure 2 ? a schematic perspective view of the plant according to the invention.

Figure 3 ? a schematic isometric view of a box-shaped container of the system in figure 2.

Figure 4a ? a bottom view of a back wall of the box-shaped container of figure 3.

Figure 4b ? a top view of the back wall of the box-shaped container in figure 3.

Figure 4c ? a side view of the bottom wall of the box-shaped container of figure 3.

Figure 5 ? a sectional view along the plane V-V of figure 4b.

Figure 6 ? a schematic view of a control circuit of the plant according to the invention.

BEST WAY TO CARRY OUT THE INVENTION

With particular reference to these figures, yes? The reference numeral 10 generally designates a plant for glazing manufactured articles, in particular ceramic manufactured articles such as for example tiles.

The plant 10 comprises a conveyor 20 configured to support at least one article M in support on its own lower support surface M1 opposite to an upper surface M2 to be glazed.

The conveyor 20 comprises a horizontal support surface A on which the articles M are intended to rest with their upper surface M2 to be glazed facing upwards.

The conveyor 20 preferably comprises a movement unit for moving the article on the support plane A along a predetermined horizontal movement direction B (substantially rectilinear).

In the preferred example illustrated, the handling assembly comprises a belt conveyor, in particular the handling assembly comprises at least one pair of conveyor belts 21 arranged parallel to each other and to the direction of movement.

The conveyor belts 21 of the pair of conveyor belts are coplanar so that an external surface of the upper branch of the same is able to define the horizontal support surface A on which the articles M to be glazed rest. The conveyor belts 21 are stretched between a pair of end cylinders, arranged for example with an axis orthogonal to the movement direction B, at least one of which is motorized, and on which the conveyor belts 21 are at least partially wound.

An internal surface of the conveyor belts 21 ? then in contact with said cylinders, able to guarantee the movement of the conveyor belts 21 themselves.

In particular, at least one cylinder ? connected to an engine (not shown in the figure), which ? suitable for causing said cylinder to rotate around its axis.

In the example shown in the figure, the cylinder in turn transmits the movement to the conveyor belts 21 by means of a gear system 23.

It is not excluded that the transmission of the movement from the cylinder to the conveyor belts 21 can take place by means of a transmission chain, a belt, or other known motion transmission systems.

In the example shown in the figure, the movement unit comprises a pair of similar or identical belt conveyors, which are placed in sequence one after the other along the movement direction B at a predetermined non-zero distance between them.

In particular, a first extremity? 210 upstream of the conveyor belts 21 of the first conveyor corresponds to a loading area of the product M to be glazed in the plant 10, and a second end? 221 downstream of the second conveyor corresponds to an unloading area of the glazed article M from the plant 10. As mentioned, the first conveyor and the second conveyor are spaced apart in the movement direction B, so that between a second end? 211 downstream of the first conveyor and a first extremity? 220 upstream of the second conveyor a passage opening 24 is defined (having a dimension smaller than the length of the tiles to be glazed along the movement direction B).

The transporter 20 ? also equipped with a support frame 25 comprising at least one lateral side 250, which rests on the ground at one end? lower, and supports the handling unit at an opposite end? superior.

The support frame 25, in correspondence with a central area of the lateral side 250, substantially aligned vertically (and below) of the passage opening 24, comprises a discharge opening 251 (whose main function will be specified below).

In alternative embodiments not shown in the figure, the movement group could comprise a roller conveyor, or other conveyor suitable for glazing plants of the known type.

The plant 10 particularly comprises a device 30 for glazing items M, i.e. a device configured to dispense a predetermined (or predeterminable) quantity? of glaze (shaped like a veil or a curtain) on the upper surface M2 of the manufactured article M resting on the support surface A made available by the movement unit (and in relative motion with respect to the device 30).

The device 30 comprises a box-like container 31 for example having the overall shape of a hollow parallelepiped.

The box container 31 ? format (includes or consists of):

- a bottom wall 32, for example substantially quadrangular (in plan view), having a prevalent longitudinal dimension which defines the length of the box-like container 31 (and a minor orthogonal dimension which defines the width of the box-like container 31),

- an opposing upper wall 33, parallel to the bottom wall 32, which ? placed at a distance from the bottom wall 32 substantially equal to a vertical dimension which defines the height of the box-like container 31, and

- a shell, for example formed by four substantially vertical and substantially quadrangular infill walls joined together and joined at opposite ends? to the bottom wall 32 and to the upper wall 33, of which a rear wall 34, an opposite front wall 35 (of the same shape as the rear wall 34) and a pair of side walls 36 adjacent to the rear wall 34 and to the front wall 35.

The internal volume of the box-like container 31 ? bounded by these walls. The bottom wall 32 of the box-like container 31? equipped with at least one passage opening 320 elongated along a horizontal longitudinal axis C and, for example, arranged in a substantially central position, through which the internal volume of the box-like container 31 communicates with the outside.

In particular, the box-shaped container 31 contains a glaze for glazing the manufactured articles M, and the passage opening 320 of the bottom wall 32? configured to let out a veil of enamel.

The Polish ? an aqueous suspension of powder, for example glass powder or other ceramic material, which preferably must be fired (together with the substrate) to make a glazed tile.

In a preferred embodiment of the invention the passage opening 320 is made up of a plurality of through holes 322, for example arranged in a row, preferably a single row, and aligned along a horizontal alignment direction parallel to the longitudinal axis C and orthogonal to the reciprocal movement direction B between the articles M and the box-like container 31 ( imposed by the carrier 20).

Preferably, each through hole 322 ? formed by a respective dispensing nozzle 323 (or needle) fixed to the back wall 32.

In practice, the device 30 comprises a plurality of dispensing nozzles 323 (each of which defines a respective through hole 322 for the glaze to exit from the box-like container 31), which are arranged in a row, preferably a single row, and aligned along the alignment direction and which, overall, they define the aforesaid passage opening 320 which causes the aforesaid veil of glaze (composed in turn by a plurality of vertical jets of glaze, each of which is dispensed by the single dispensing nozzle 323) to exit the box-like container 31.

For example, each dispensing nozzle 323 comprises an elongated tubular body 3230 which is equipped with a longitudinal axis (straight) perpendicular to the movement direction B and to the longitudinal axis C of the passage opening 320, or perpendicular to the support surface A.

Each dispensing nozzle 323 has a cavity longitudinal interior which defines the through hole 322 from which the enamel emerges.

In practice, the dispensing nozzle 323 has a first end? upper axial (open) that ? arranged inside the box-shaped container 31, for example at a higher level than the inner face of the bottom wall 32 or substantially flush with it, and an opposite second end? lower axial (open) facing or ? arranged outside the box-like container 31, for example at a lower level than the outer face of the bottom wall 32 (or, at most, substantially flush with it).

Preferably, the second end? axial (and the first axial end) of each tubular body 3230 lies in a plane orthogonal to the longitudinal axis of the tubular body 3230.

For example, the tubular body 3230 of each dispensing nozzle 323 has a length substantially between 30 mm and 60 mm, preferably equal to 50 mm? 55m

Preferably, the tubular body 3230 protrudes below the (external face of) the bottom wall 32 by at least one axial section.

This axial section protruding below the bottom wall 32 of each tubular body 3230 preferably has a length substantially between 10 mm and 20 mm, preferably equal to 15 mm? 2mm

The tubular body 3230 of each dispensing nozzle 323 has a constant circular internal transversal section along its entire longitudinal development, with an internal diameter substantially equal to 0.8 mm? 0.1mm.

For example, each dispensing nozzle 323 ? fixed to the back wall 32, for example in a removable or permanent way.

For example, each dispensing nozzle 323 can be fixed to the back wall 32 for example by interference.

In practice, each dispensing nozzle 323 can be inserted axially, by interference, into an axial hole made in the back wall 32 (which passes from side to side of the same).

It is not excluded that each dispensing nozzle 323 can be fixed in a different way, such as screwed or similar, or can be permanently associated, for example welded to or co-molded with the bottom wall 32.

Each 323 dispensing nozzle can? present an annular enlargement 3231 At (or near?) the first extremity? upper axial of the delivery nozzle 323, which ? configured to rest on the (inner wall of) the back wall 32.

For example, between the annular enlargement 3231 and the (inner wall of) the back wall 32 ? defined a sealing ring (for example defined integral with the annular enlargement 3231).

The annular enlargement 3231 pu? present a substantially conical shape, so as to essentially act as an invitation funnel for channeling the enamel inside the cavity? inside of the tubular body 3230.

The through holes 322 of the row of through holes (ie the dispensing nozzles 323) are mutually equidistant along said alignment direction, preferably with a pitch substantially equal to 5 mm? 1mm.

.

Furthermore, it is not excluded that the through holes 322 (ie the dispensing nozzles 323) can be arranged on a plurality of? of rows, for example a pair of rows side by side along a side by side direction orthogonal to the longitudinal axis C.

Furthermore, the bottom wall 32 of the container body 31 is preferably internally shaped, so as to facilitate the escape of the glaze from the passage opening 320.

In particular, an internal surface (of the box-like container 31) of the bottom wall 32 defines an axial concave seat 324, which for example extends along the entire longitudinal dimension of the bottom wall 32 itself.

Said concave seat 324 therefore defines a wide mouth at the extreme edges of the bottom wall 32 and a narrow outlet at the passage opening 320, so as to flow the glaze towards the passage opening 320 (i.e. the delivery nozzles 323 which define it).

In this case, the bottom wall 32 has a greater thickness (in the direction orthogonal to its longitudinal dimension) in correspondence with the extreme edges, which decreases to a lesser thickness in correspondence with the passage opening 320.

In a preferred embodiment of the invention, the bottom wall 32 of the box-like container 31 is associated with it in a removable way.

For this purpose, the back wall 32 ? fixable (rigidly) in a resolvable way to the infill walls 34,35,36 of the box-shaped container 31, for example by means of fixing members such as screws or bolts (which abut from the bottom and/or from the sides into the shell).

Also the infill walls 34,35,36, adjacent to the bottom wall 32, or the upper wall 33, opposite to the bottom wall 32, can be opened and therefore fixed (rigidly) in a resolvable way to the corresponding adjacent walls of the box-like container 31, for example by means of fixation members that can be solved as screws or bolts.

Alternatively, the box-shaped container 31 can at least partially comprising a monolithic body, to which for example the bottom wall 32 and possibly another wall adjacent or opposite to it can be fixed.

In a preferred embodiment, above the back wall 32? fixable a filtering septum 325, which ? configured to filter the glaze directed towards the passage opening 320 defined by the through holes 322 of the dispensing nozzles 323.

For example, the filtering septum 325 ? defined by a membrane or filtering net, for example planar (horizontal), which ? interposed between the infill walls 34,35,36 and the bottom wall 32 (so as to have its perimetric edge clamped between them).

In practice, all the glaze contained in the box-like container 31 is forced to cross (due to gravity and/or other thrust forces) the filtering septum 325 before being able to exit (filtered) from the passage opening 320 defined by the through holes 322 of the dispensing nozzles 323.

The front wall 35 of the box-shaped container 31 also has an opening 350 closed in a removable way by a plugging element 351.

In the embodiment illustrated in the figures, the opening 350 of the front wall 35 is consisting of a through hole, for example substantially quadrangular and slightly smaller than the dimensions of the front wall 35 itself.

The bottom wall 32 of the box-like container 31? preferably made of a plastic material, preferably of polyurethane.

However, it is not excluded that this bottom wall 32 can be made of metal or other material.

The dispensing nozzles 323, for example their tubular body 3230 (with the exception of the annular enlargement 3231 which could be made of a plastic and/or elastic material), ? made of metal, for example steel (stainless).

The upper wall 33 and the buffer walls 34,35,36 are for example made of metallic material, for example steel.

The bottom wall 32 of the box-shaped container 31 is superimposed in plan view on at least a portion of the support surface A and at a distance (not zero) from it.

In particular, the box-shaped container 31? mounted on the support frame 25 of the conveyor 20, in particular so that the bottom wall 32 of the box-like container 31 faces the passageway 24 between the pairs of conveyors 21.

In this way, the box-shaped container 31 can dispensing glaze onto the upper surface M2 of the manufactured article M which passes in correspondence with the passageway 24 between the pairs of conveyors 21, and the excess glaze which does not adhere to said upper surface M2 falls through the passageway 24 and ? directed by a suitable collector and conveyor towards the discharge opening 251 of the support frame 25.

For example, the box-like container 31 ? movably mounted with respect to the support frame 25.

The support frame 25 comprises a support structure 26 of the box-shaped container 31, rigidly connected to the support frame 25 above the support surface A.

The support structure 26 comprises a pair of support walls 260 distant from each other by a distance equal to or greater than the distance between two opposite side walls 36 of the box-like container 31.

Rigidly fixed to the support walls 260 are longitudinal guides 261, for example defined by grooved longitudinal members, with a horizontal longitudinal axis, to which suitable sliding slides 262 are connected, fixed to the opposite side walls 36 of the box-like container 31.

The box container 31 ? sliding with respect to the longitudinal guides 261 along a sliding direction D parallel to the longitudinal axis C of the passage opening 320 of the bottom wall 32.

Furthermore, at least one longitudinal guide 261 comprises a locking system of the box-shaped container 31, configured to lock the same in position on the longitudinal guides 261, for example in a predefined axial working position on the support surface A.

In detail, said locking system ? adapted to allow at least two relative positions of the box-shaped container 31 with respect to the longitudinal guides 261, of which a first retracted working position, in which the box-shaped container 31 is centered on the support surface A (defined by the conveyor 20 with respect to a median vertical and longitudinal plane thereof), and a second advanced rest position, in which the box-like container 31 is? vertically decentralized from the support plane A, i.e. ? arranged laterally with respect to it (or on the same side of the longitudinal vertical median plane thereof) in a lateral area of the support frame 25 accessible by an operator, in order to facilitate washing or any maintenance of the box-shaped container 31.

In particular, the locking system comprises for example a release button 27, rigidly connected to the longitudinal guide 261, and able to be manually moved for example to lock (and release) axially the box-shaped container 31 by means of forced contact (and detachment) with one of its side walls 36 equipped with engagement stops for this release button 27.

Each support wall 260 of the support structure 26 ? for example movably associated, for example rotatable (about a horizontal oscillation axis and parallel to the movement direction B), with respect to the support frame 25 of the conveyor 20.

Preferably, the support walls 260 are configured to incline the longitudinal guides 261 between a working configuration, in which they are substantially horizontal, and a washing configuration, in which they are inclined with respect to the horizontal (for example by an acute angle, preferably less than 45?, for example facing the side area of the support frame 25 accessible by the operator).

For example, the support walls 260 are operated by actuators 28, for example linear, supported by the support frame 25 of the conveyor 20.

In particular, each actuator 28 ? connected to a vertical support part 263 fixed to the support wall 260.

In this way, the box-shaped container 31, associated with (the longitudinal guides 261 of) the support structure 26 by means of the sliding slides 262, is associated in an oscillating manner with respect to the support frame 25.

In particular, the box-shaped container 31? selectively positionable between a working position, corresponding to the working configuration of the longitudinal guides 261 to a retracted position of the linear actuators 28, in which the bottom wall 32 of the box-like container 31 is substantially horizontal, and a washing position, corresponding to the washing configuration of the longitudinal guides 261 to an extracted position of the linear actuators 28, in which the bottom wall 32 of the box-like container 31 is inclined to the horizontal, for example so that the portion pi? top of the box-like container 31 is arranged in the side area of the support frame 25 accessible by the operator.

The box-shaped container 31 also comprises at least one handle device, able to facilitate the movement of the box-shaped container 31 itself and/or to allow the opening of some walls of the same.

In the preferred example illustrated in the figure, the box-shaped container 31 comprises a first handle device, i.e. a first handle 37, rigidly fixed in correspondence with the plugging element 351 of the front wall 35.

Said first handle 37 can? for example, allowing the plugging element 351 to be removed from the opening 350 of the front wall 35 and/or, when the plugging element 351 is ? rigidly connected to the front wall 35, the first handle 37 can? facilitate the handling of the box container 31.

Furthermore, the box-shaped container 31 comprises a second handle device, i.e. a second handle 38, rigidly fixed at the upper wall 33 and suitable for facilitating the handling of the box-shaped container 31 and/or the removal of the upper wall 33, in case which this is fixed in a resolvable way to the infill walls 34,35,36 of the box-like container 31.

The box-like container 31 also comprises a first opening 310 for the glaze inlet, which is for example made in correspondence with one of the infill walls 34,35,36 of the box-shaped container 31, preferably equipped with a connection union.

The box-shaped container 31 also comprises a second opening 311 for pressurized air, which for example ? made at the upper wall 33 of the box-like container 31, preferably equipped with a connection fitting.

The box-shaped container 31 also comprises a third air intake opening 312, which for example ? made at the upper wall 33 of the box-like container 31, preferably equipped with a connection union.

In particular, the first opening 310 ? connected, via the connection union, to a glaze delivery pump 11, which draws the glaze from a tank 12, for example equipped with a mixer, to send it to the box-shaped container 31.

The device 30 comprises at least one dispensing unit 40 configured to generate a positive pressure in the box-like container 31 at at least a dispensing pressure value greater than atmospheric pressure.

Said delivery group ? configured to introduce pressurized air into the box-like container 31, through the second opening 311 of the same, allowing the forced escape of glaze from the passage opening 320 of the bottom wall 32.

In particular, the dispensing unit 40 comprises a pressure regulator 41 configured to vary the dispensing pressure value to regulate the flow of glaze leaving the passage opening 320.

The device 30 also comprises a pressure control unit 50 inside the box-shaped container 31 configured to generate a vacuum inside the same, at a pressure value lower than an atmospheric pressure value.

In particular, said control unit 50 comprises a vacuum generator 51 configured to suck air from inside the box-like container 31 (or generate a vacuum condition inside the box-like container itself), by means of the third opening 312 of the same, allowing to stop the outflow of glaze from the passage opening 320 of the bottom wall 32 (or from the through holes 322 defined by the dispensing nozzles 323).

The system 10 comprises, in particular, a control circuit 60 configured to allow operation and/or to control and set the dispensing group 40 and/or the control group 50.

The control circuit 60 comprises, for example, a compressor 13 capable of allowing pressurized air to enter the circuit 60.

The pressurized air entering the control circuit 60 can selectively be directed to the dispensing group 40, to the control group 50 or to a filling branch 62.

The dispensing unit 40 and the control unit 50 are in communication respectively with the second opening 311 and with the third opening 312 of the box-like container 31 via a regulated pressure outlet 601 and a regulated vacuum outlet 602, respectively, and the filling 62 ? in communication with (the delivery of) the glaze delivery pump 11 and with the first opening 310 of the box-like container 31 through a glaze outlet 603.

The air under pressure? directed initially through a filter F and a safety valve S.

Said safety valve S ? a pressure reducing valve designed to reduce the incoming air pressure to make it stable at the outlet.

In particular, the pressure regulation takes place by means of a calibrated spring, and the control of the same is obtained by piloting a pressure switch placed downstream of the safety valve S.

The control circuit 60 comprises, downstream of the safety valve S, mainly a first pressure branch 61, a second filling branch 62 and a third vacuum branch 63.

The first pressure branch 61 ? initially intercepted by the pressure regulator 41.

In particular, the pressure regulator 41 comprises a microprocessor 410 capable of establishing a predetermined pressure of the air to be delivered.

Said microprocessor 410, following the setting of the predetermined pressure, actuates at least one solenoid valve 610 suitable for allowing the passage of pressurized air towards the regulated pressure outlet 601.

The 610 solenoid valve? therefore operatively movable (electrically operated by the microprocessor 410) between a first position in which it sends air under pressure towards the regulated pressure outlet 601, and a second position in which it is? closed and does not send pressurized air.

The 610 solenoid valve? for example an electrically actuated valve using a single coil solenoid and spring return.

The first pressure branch 61 ? intercepted, downstream of the pressure regulator 41, by a passage valve 611, i.e. an isolation cock preferably shaped like a ball valve.

Said passage valve 611 ? preferably a two-port, two-position valve, configured to selectively open or close the first pressure branch 61 at the regulated pressure outlet 601.

The passage valve 611, in particular, is opened and closed by a first control valve 612.

Said first control valve 612 ? preferably a solenoid valve which is in turn controlled by the application of a pneumatic pressure in a pilot stage.

The second fill branch 62 ? initially intercepted by a further solenoid valve 620 controlled in its first passage position and in its second closed position, by electric actuation and application of a pneumatic pressure in a pilot stage.

Downstream of the further solenoid valve 620, the second filling branch ? intercepted by a pneumatic actuator 621 which allows the glaze to be sent towards the glaze outlet 603, when the further solenoid valve 620 ? in his first pass position.

The third vacuum branch 63, initially intercepted by a second solenoid valve 630, is controlled by a vacuum switch able to monitor and guarantee safety to the control circuit 60 which is preparing to generate a predetermined depression.

The second solenoid valve 630 ? operably movable between an operating position, controlled by electric actuation and application of a pneumatic pressure in a pilot stage, and a non-operating position.

The control circuit 60 particularly comprises a pair of tanks, of which a first tank 52 with maximum vacuum level, and a second tank 53 with controlled vacuum level, connected to each other and suitable for generating a depression inside the box-like container 31.

In particular, the first tank 52, placed downstream of the second solenoid valve 630 on the third vacuum branch 63, is connected to the vacuum generator 51.

The vacuum generator 51 ? configured to generate a vacuum inside the first tank 52 and the second tank 53 (as will be explained later), and via the regulated vacuum outlet 602 to generate a vacuum inside the box-like container 31, such as to block the ?dispensing nail polish.

The vacuum generator 51 preferably comprises a venturi meter 510.

In detail, the venturi meter 510 comprises an inlet P for pressurized air, a restriction section at a second inlet U, and an outlet R.

The air entering P, directed to the third vacuum branch 63 by the second solenoid valve 630 in the operating position, undergoes an acceleration and a simultaneous reduction in pressure in correspondence with the restriction section of the venturi meter 510, allowing air to be drawn from the first tank 52 and generating a vacuum inside it.

In particular, between the first tank 52 and the second inlet U of the venturi meter 510 ? interposed a check valve 631 with spring.

Said check valve 631 allows the passage of air from the first tank 52 to the second inlet U of the venturi meter 510 only if the air pressure upstream of the same, ie at the outlet from the first tank 52, is greater than the pressure downstream of the check valve 631, i.e. at the second inlet U of the venturi meter 510, added to the pressure exerted by the force of the spring.

In other words, the 631 spring-loaded check valve ? calibrated so as to generate a predetermined depression value inside the first tank 52.

The first tank 52 communicates with the second tank 53 via a connection branch 64.

Said connection branch 64 ? intercepted by a second safety valve 640.

The second safety valve 640 ? a pressure regulating valve suitable for regulating the incoming air pressure to make it stable at the outlet.

In particular, the pressure regulation takes place by means of a calibrated spring, and the control of the same is obtained by piloting a pressure switch placed downstream of the second safety valve 640.

The connection branch 64 ? further intercepted by at least a first further vacuum switch, and by a second further vacuum switch, able to monitor and establish the respective vacuum level of each tank.

The connection branch 64, which connects the first tank 52 to the second tank 53, allows a vacuum to be created in correspondence with the second tank 53, which is controlled on the basis of the level set by the vacuum switch. The second tank 53 is then in turn connected by means of a second flow valve 641 to the regulated vacuum outlet 602.

Said second passage valve 641, i.e. an isolation cock, is preferably shaped like a ball valve.

The second pass valve 641 ? preferably a two-port, two-position valve configured to selectively open or close the regulated vacuum outlet 602.

The second passage valve 641, in particular, is opened and closed by a second control valve 642.

The second control valve 642 ? preferably a solenoid valve which is in turn controlled by the application of a pneumatic pressure in a pilot stage.

The first tank 52 and the second tank 53 are also connected to a respective tap, or preferably a ball valve, configured to open or close the corresponding tank as required.

In an alternative embodiment not shown in the figures, the control circuit 60 could comprise a single pressure/vacuum branch intercepted by an electronically controlled proportional valve, suitable for regulating the pressure delivery or the creation of a depression in matching the box container.

The system 10 also comprises a sensing assembly operatively connected to the control circuit 60 and/or to the glaze delivery pump 11.

The detection group comprises at least one level sensor 71, connected to the box-like container 31 and to the control circuit 60 and configured to measure the quantity? of enamel contained in the same.

For example, the level sensor 71 ? of the capacitive type, applied to the outside of the box-like container 31 and able to detect the punctual and/or continuous level of the glaze through a wall of the box-like container 31 itself.

It is not excluded that the level sensor 71 could be of the optical type, ultrasound, or any other type suitable for glazing plants.

The level sensor 71 ? for example connected to the glaze delivery pump 11 so as to allow the filling of the box-shaped container 31 when the level of glaze falls below a predetermined threshold value, or to block the filling of the box-shaped container 31 when the level of glaze rises below above a predetermined limit value.

Also, the 71 level sensor? for example connected to further solenoid valve 620 of the filling branch 62 of the control circuit 60, so as to control the first passage position and the second closing position thereof.

In this way, the level sensor 71 allows the movement of the pneumatic actuator 621 which sends glaze to the box-shaped container, when the level of glaze falls below a pre-set threshold value, or which blocks the delivery of glaze to the box-shaped container , when the glaze level rises above a pre-set limit value.

The sensing assembly also comprises a position sensor 72, for example a position transducer, operatively connected to the control circuit 60 and configured for example to control the relative position of the manufactured articles M with respect to the box-like container 31.

In particular, the position sensor 72 ? adapted to convert, by means of the control circuit 60, the relative position of the manufactured articles M with respect to the box-shaped container 31, into an air pressure value, allowing to dispense a film of glaze or to block its leakage from the box-shaped container 31.

The plant 10 also comprises a unit? control electronics U configured to manage the operation of the system in an automated way 10.

The unit control electronics U ?, for example, operatively connected to the control circuit 60 and/or to the glaze dispensing pump 11 and/or to the sensing group 71,72 for the management and control of the automated operation of the system 10.

In the light of what has been described above, the operation of the plant 10 is the following.

A manufactured article M or a sequence of manufactured articles M to be glazed is made to advance in the movement direction B by the conveyors 21, with the upper surface M2 to be glazed facing upwards.

Each artifact M so? arranged on the support surface A, it advances below the box-shaped container 31, which dispenses glaze from the passage opening 320 defined by the set of through holes 322 of the dispensing nozzles 323.

In practice, each dispensing nozzle 323 dispenses a (perfectly) vertical jet of glaze, which by joining the jet of the other dispensing nozzles 323 generates a uniform veil of glaze falling vertically onto the upper surface M2 of the article M advancing along the direction of handling B. The veil of glaze generated by the dispensing nozzles 323, thanks to their conformation and mutual distance (and to the dispensing pressure and/or the advancement speed of the manufactured articles M) homogeneously covers the upper surface M2 of the manufactured article M advancing along the movement direction B.

In particular, the dispensing of glaze is controlled according to the position sensor 72 operatively connected to the control circuit 60.

In particular:

- by means of the pressure regulator 41 ? It is possible to set the pressure at which to dispense glaze (thus regulating the quantity of glaze on the product M);

- by means of the vacuum generator 51 ? It is possible to generate a depression in the box-shaped container 31 so as to block the delivery of glaze.

The excess glaze, dispensed from the box-like container 31 and which does not adhere to the product M, is discharged from the passage port 24 between the conveyors 21 through the discharge opening 251 in correspondence with the tank 12, from which it is drawn up by the pump 11 and returned inside the box-like container 31 to be dispensed again.

Any lack or excess of glaze inside the box-like container 31 is also detected by the level sensor 71 operatively connected to the pump 11.

Furthermore, when the system 10 is not? operational, ? It is possible to tilt the box-shaped container 31 with respect to the support frame 25 by actuating the linear actuators 28, so as to facilitate the cleaning and/or maintenance operations of the box-shaped container 31 itself.

The invention so? conceived ? susceptible to numerous modifications and variations, all of which are within the scope of the inventive concept.

Furthermore, all the details can be replaced by other technically equivalent elements. In practice, the materials used, as well as? the contingent shapes and dimensions may be any according to requirements without thereby departing from the scope of protection of the following claims.

Claims (10)

1. A device (30) for glazing manufactured articles (M) comprising: a box-like container (31) in which ? contains an enamel for glazing manufactured articles (M), in which the box-shaped container (31) comprises a bottom wall (32) equipped with at least one passage opening (320) elongated along a horizontal longitudinal axis (C) and configured to release a veil of glaze in which the passage opening (320) ? made up of a plurality of through holes (322) arranged in a single row and aligned along a horizontal alignment direction parallel to the longitudinal axis (C) and orthogonal to a reciprocal movement direction (B) between the articles (M) and the box-like container (31 ), characterized by the fact that: each through hole (322) ? formed by a respective delivery nozzle (323) fixed to the back wall (32). 2. The device (30) according to claim 1, wherein each dispensing nozzle (323) comprises an elongated tubular body (3230) provided with a longitudinal axis orthogonal to the movement direction (B) and to the longitudinal axis (C) of the passage opening (320), wherein the tubular body (323) preferably protrudes below the bottom wall (32) by at least one axial section. 3. The device (30) according to the preceding claim, wherein the tubular body (3230) has a length substantially comprised between 30 mm and 60 mm, preferably equal to 50 mm? 5m and/or the axial section protruding below the bottom wall (32) of each tubular body (3230) has a length substantially between 10 mm and 20 mm, preferably equal to 15 mm? 2mm. 4. The device (30) according to claim 2, wherein each tubular body (3230) has a constant circular internal transversal section along its entire longitudinal development, with an internal diameter substantially equal to 0.8 mm? 0.1mm. 5. The device (30) according to claim 1, in which the through holes (322) of the row of through holes are mutually equidistant, preferably with a pitch substantially equal to 5 mm? 1mm. 6. The device (30) according to claim 1, which comprises a pressure control assembly (50) inside the box-shaped container (31) configured to generate a vacuum inside the box-shaped container (31) at a value of pressure lower than a value of atmospheric pressure to stop the escape of glaze from the passage opening (320). The device (30) according to claim 6, wherein the control assembly (50) comprises a vacuum generator (51). The device (30) according to claim 1, wherein the bottom wall (32) is made of a plastic material, preferably polyurethane and each dispensing nozzle (323) ? made of metal material. 9. The device (30) according to claim 1, which comprises at least one dispensing assembly (40) configured to generate a positive pressure in the box-like container (31) at at least a dispensing pressure value higher than atmospheric pressure to allow the leakage forced enamel from the passage opening (320). 10. A plant (10) for the glazing of manufactured articles (M) which includes: - a conveyor (20) equipped with a support surface (A) configured to support at least one article (M) and equipped with a handling unit (21) to move the article (M) along a movement direction (B ) horizontal; - a device (30) according to claim 1, in which the bottom wall (32) of the box-shaped container (31) is superimposed in plan view on at least a section of the support surface (A) with the dispensing nozzles (323) placed at a non-zero distance from it.