IT202000028433A1 - PAINT GUN EQUIPPED WITH AN IMPROVED REGULATION SYSTEM - Google Patents

Description

DESCRIPTION

of the patent for industrial invention entitled:

?PAINT GUN EQUIPPED WITH AN IMPROVED REGULATION SYSTEM?

TECHNICAL FIELD

The present invention ? relating to a paint gun, in particular to an airbrush gun equipped with a system for regulating the flow of paint fluid.

STATE OF THE ART NOTE

Known painting systems usually comprise at least one painting gun configured to spray a painting fluid onto an object to be painted.

This airbrush gun therefore comprises an opening which allows the outlet of this painting fluid, usually under pressure, directed towards the object to be painted.

At the state of the art, the regulation of the fluid flow in painting circuits where airbrush guns are used can take place in the following ways:

? By regulating the pressure of the centralized paint supply pump located upstream of the circuit;

? By manually adjusting the adjustment handwheel on each gun; or again

? Using servo-pneumatic throttling devices to be placed between the color feed tube and the gun;

Clearly a centralized control where the regulation of the flow of the painting fluid? carried out upstream of the supply pipes to the guns, is inaccurate, if the same flow rate of fluid is supplied to all the guns why? each gun would be fed with a flow rate capable of meeting the needs of the one with greater need? of fluid. A dedicated adjustment of each gun, at the hydraulic level, would instead be extremely complex, cumbersome and expensive.

A manual adjustment, on the other hand, significantly affects the maintenance time of the painting systems, having to manually adjust each gun to change the quantity? of paint to dispense.

Finally, the use of intermediate adjustment devices to be inserted in line on the paint circuit do not allow precise adjustment when small quantities are required. of product to be dispensed, cause an increase in system management time as ? require more time for maintenance, and may be subject to clogging due to the small internal passages where the paint flows.

AND? therefore felt the need to provide paint guns that can be adjusted in an automatic, compact, precise and economical way.

AND? otherwise? felt the need to limit maintenance times and without having to add other devices that act on the paint supply circuit.

Purpose of the present invention? meet the above requirements.

SUMMARY OF THE INVENTION

The aforementioned purpose? achieved by a paint gun and a paint system as claimed in the attached independent claims.

Further preferred embodiments of the invention are made according to the dependent claims or claims linked to the aforementioned independent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, a preferred embodiment is described below, by way of non-limiting example and with reference to the attached drawings in which:

? Figure 1 ? a longitudinal sectional view of a painting system comprising a painting gun according to the invention;

? figure 2 ? a sectional view along the line II-II of the regulation system of figure 1;

? Figures 3 and 4 are enlarged partial longitudinal sectional views of different operating phases of the adjustment system for the paint gun of Figure 1;

? figures 5A to 5F are longitudinal sectional views of different operating phases of the regulation system for the paint gun of the system of figure 1 ; And ? figure 6 ? a perspective view, partially exploded, of the paint gun of the system of figure 1.

DETAILED DESCRIPTION OF THE INVENTION

In figure 1 ? shown is a portion of a painting system 1 comprising at least one painting assembly 2 each equipped with a painting gun 3. In the illustrated figure ? There is a single paint assembly 2, for simplicity. In particular, the paint gun 3 extends along a longitudinal axis A and ? supported by a support 4 which can be fixed to a fixed body (not shown) of the painting system 1.

Advantageously, the support 4 comprises a fixing portion 4a configured to allow the fixing of the support 4 to the body of the painting system 1.

Support 4 also defines? a first and and a second lateral relief 5 extending longitudinally parallel to the axis A and projecting from the fixing portion 4a. Preferably support 4 ? made of material that remains unchanged and stable over time, such as stainless steel.

The first and second lateral reliefs 5 transversally delimit a seat suitable for partially housing the paint gun 3.

The paint gun 3 defines a casing 3a, preferably cylindrical in shape and configured to delimit an internal space 3b adapted to house a flow regulation system 6 of the paint fluid as described below.

As known, the flow regulation system 6 comprises a rod 6a configured to open or close the free section of an opening 7, preferably defined as the outlet section of a nozzle. The opening 7 ? fluidically connected to a source 8 of painting fluid, as per se? known.

In particular, the 6a auction ? connected to adjustment means 9 configured to adjust the maximum vertical stroke position along axis A of said rod 6a as described below.

How by itself? known, the movement of the rod 6a along the axis A ? implemented through a pneumatic system 6b. In particular, the pneumatic system 6b comprises a small piston 6c actuated by means of the air inlet from the duct 6d? and recalled in a neutral position what? in closing stop by elastic means 6f when the air is made to flow out of the duct 6d?.

To the 6c piston? connected to a second piston 6g integral with it and configured to allow the passage of compressed air coming from a duct 6d?? what can? then flow towards the opening 7. In particular, the air flows in separate ducts fluidically with respect to the opening 7 and communicating with the outside through orifices 3b made around the opening 7.

Since the components of the flow regulation system 6 are per se? known, will not be pi? described in detail for the sake of brevity.

The 6th auction ? carried by the cylinder 6c and follows its movements between a first, lower end position, in which the opening 7 is closed by the rod 6a, and a second, upper end position, whose maximum stroke ? delimited by the adjustment means 9, wherein between rod 6a and opening 7 ? frees a passage section for the passage of painting fluid coming from the source 8.

Said adjustment means 9 essentially comprise a handwheel 10 configured to rotate around the axis A and actuator means 11 configured to regulate this rotation of the handwheel 10.

Advantageously, these actuator means 11 are pneumatic actuator means.

According to the advantageous embodiment described, the adjustment means 9 comprise first actuator means 11? configured to allow the handwheel 10 to rotate clockwise about axis A and according to actuator means 11?? configured to allow the handwheel 10 to rotate counterclockwise around axis A. Clearly the actuator means 11?, 11?? they work alternately with respect to each other.

The clockwise or counterclockwise rotation of the handwheel 10 makes it possible, respectively, to reduce or increase the second end position, i.e. the upper abutment of the rod 6a, thus varying the maximum passage section between the rod 6a and the opening 7.

According to an embodiment illustrated in Figure 2 and following, each of the actuator means 11 comprises a plunger 12 housed freely with respect to translation in a support element 13 and configured to cooperate in contact with respective seats 14 made on the handwheel 10 to control the rotation.

Preferably, the seats 14 are mutually angularly equally spaced circumferentially so that there is the same angular pitch between one seat 14 and the other. In the case described are there twenty locations 14 and equally spaced by 18? from each other around the axis A.

In particular, the support element 13 ? configured to be fixed to the support 4 in such a position as to be able to laterally wrap, at least partially, the handwheel 10 of the paint gun 3. In particular, when fixed to the support 4, the fastening element extends projectingly from the fastening portion 4a of the support 4, preferably perpendicular to it.

Preferably, the support element 13 therefore comprises a fixing portion configured to allow it to be fixed to the support 4 and an end portion configured to wrap, at least in part, the handwheel 10 of the paint gun 3.

Preferably, this end portion defines an arcuate portion facing the handwheel 10 and more. preferably concentric to it.

The support element 13 ? advantageously hollow, that is? defines a through opening 15 configured to house the push rod 12 inside it and allow its translational movement along an axis C, preferably parallel to the axes A and B.

In particular, the through opening 15 comprises a first portion 15?, an intermediate portion 15?? and a second portion 15???, opposite along the axis C with respect to the first portion 15?. Advantageously, all portions 15?, 15??, 15??? are advantageously of axisymmetric shape, preferably cylindrical and the first portion 15? does it have transversal dimensions with respect to the C axis that are greater than the intermediate portion 15?? which in turn has transversal dimensions with respect to the C axis that are greater than the second portion 15???. According to the illustrated shape, the diameter of the first portion 15? ? greater than the diameter of the intermediate portion 15?? which in turn ? greater than the diameter of the second portion 15???.

The second portion 15??? ? sized so that the push rod 12 cooperates in contact with the internal walls radially delimiting the second portion 15???.

In particular, the ferrule 12 comprises a first end portion 12a configured to cooperate mechanically with the handwheel 10 and partially slidable in the second portion 15??? opening 15 and a second portion of? end? 12b, opposite the first portion of? extremity? 12a, and configured to scroll within the first portion 15? fluid-tight aperture 15. The first and second portions of? extremity? are connected to each other by means of an intermediate portion 12c.

The second portion of? end? 12b substantially defines a piston which therefore divides the first portion 15? in a first portion 15?a fluidically in contact with a source of fluid F under pressure and a second portion 15?b fluidly separated from the first portion 15?a.

The pressurized fluid source F, not shown, is advantageously a pneumatic source configured to selectively supply a flow F of pressurized air inside the second portion 15?b so as to exert a force on the second end portion? 12b, therefore on the tip 12.

Tip 12? configured to move along the C axis between in a first operative, rest position (figure 3) in which the first end portion? 12a does not cooperate with the handwheel 10 and a second operative, actuation position (figure 4) in which the first end portion? 12a cooperates in contact with handwheel 10.

In particular, the actuator means 11 comprise elastic means 17 configured to keep the toe 12 in the first operating condition. Preferably, these elastic means are operatively interposed between the second end portion 12b and the? support element 11?, more? preferably inside the opening 15.

According to the described embodiment, the elastic means 17 are housed inside the second and third portions 15?, 15?? of the opening 15.

In particular, the elastic means 17 comprise a helical spring 18 housed around the intermediate portion 12c of the push rod 12, preferably coaxial with it, and comprising a first end? in contact with the shoulder defined by the narrowing between the second and third portions 15??, 15??? of the opening 15 and a second end? in contact with the second portion of? extremity? 12b of the tip 12.

The ferrule 12 advantageously comprises a pawl 20 movably carried by the first end portion 12a of the push rod 12 and configured to cooperate in contact with the handwheel 10.

In particular, the pawl 20 ? advantageously L-shaped, that is? comprising a first arm 20? and a second arm 20?? connected via a hinged connection 21 to the first end portion? 12a of the push rod 12. Advantageously, the first and second arms 20?, 20?? they are made in one piece with each other. The hinge 21 allows the pawl 20 to rotate about an axis parallel to the axis A between a first and a second limit value.

In particular, the first arm 20? ? dimensioned to cooperate with the seats 14 of the handwheel 10 to command the movement of the latter when in one of the two limit conditions of rotation of the pawl 20.

The actuator means 11 advantageously comprise thrust means 23 configured to keep exerting a force directed against the push rod 12 during its travel along the respective axis C. In particular, the thrust means 23 comprise a ball positioner 25 comprising a ball 24 adapted to return in a respective seat 25 under the action of a predetermined force provided by the push rod 12.

In particular, the handwheel 10 comprises a movable portion 10? defining the aforementioned seats 14 and with which the adjustment system 9 described above cooperates and a fixed portion 10?? carried by the casing 3a and on which the movable portion 10? ? rotationally free range.

In particular, the mobile portion 10? ? integral with a threaded pin 30, for example planted inside a through opening 31, the movable portion 10?. The threaded pin 30 ? cooperating in threading with a threaded shaft 32 which is in turn connected by threading made on the internal radial surface of a through opening 33 made inside the fixed portion 10??.

The integral rotation between the threaded pin 30 brings with it the rotation of the threaded pin 31 which therefore causes the threaded shaft 32 to move along the axis A. The threaded shaft 31 acts as a stop for the rod 6a which will therefore see? modify the maximum opening light H with respect to the shaft 31 and therefore consequently the maximum opening of the space between the rod 6a and the opening 7 of the nozzle.

The adjustment system 9 also includes angular phasing means 35 configured to adjust the relative starting position of the adjustment system 9, i.e. between moving part 10? and fixed 10?? of flyer 10.

In particular, the angular phasing means 35 comprise a positioner 36, for example similar to the positioner 23, configured to cooperate with a plurality of of internal seats formed radially corresponding to the seats 14. Furthermore, the phasing means 35 comprise a reference dowel 37 formed on the external surface of the body 3a.

The phasing means 35 also comprise a further reference grain 38 made on the body 3a of the gun 3.

Does the regulation system 9 for a paint gun 3 described above work? the following, with reference to figures 5A-5F and relating to the left actuator 11?.

In figure 5A ? illustrated is a rest condition where the toe 12 is in the first operating condition. In such a condition there ? pressurized air in the chamber 15?b to such a degree as to overcome the force exerted by the elastic means 17 which therefore maintains the second end portion? 12b at a predefined rest point. In this condition the pawl 20 does not cooperate in contact with the seat 14.

In figure 5B ? shown a stroke start condition of the push rod 12 under the action of the pressurized air entering the chamber 15. In particular, the pressurized air exerts a force which exceeds that exerted by the elastic means 17 which tend to compress and therefore the second portion of? end? 12b tends to return inside the opening 15. Consequently the first end portion? 12a moves, carried by the second end portion? 12b, until the first arm 20? will touch? one of the walls of the seat 14 of the handwheel 10. During this phase the thrust means 23 prevent the rotation of the pawl 20 so that the first arm 20? yes ?hook? in the relative seat 14, cio? the ball 24 exerts a pressure against the second arm 20??.

In figure 5C ? illustrated is a rest condition where the push rod 12 is in the second operating condition. In this condition, the air under pressure in chamber 15? ? such that it completely overcomes the force exerted by the elastic means 17 and therefore the second end portion? 12b ? in contact with the shoulder between the portions 15? and 15??. In this condition the plunger 12, as the pawl 20 ? hooked into the seat 14, it has dragged the handwheel 10 in its movement which therefore rotates around the axis A.

Once the second operating condition of figure 5C has been reached, the pressurized air is made to flow out of the chamber 15. Consequently, the elastic means 17 tend to overcome the force exerted by the pressurized air in the chamber 15 and to push the second portion 12b towards the position assumed in the first operating condition of figure 5A. During this movement, the arm 20? releases from its seat 14.

During phases 5B, 5C the thrust means 23 provide a force configured to keep the push rod 12 in contact with the pawl 10.

Continuing in its movement towards the condition of figure 5A, the thrust means 23 will be in contact with only the pawl 20 (figure 5E) which will be? pushed by the sphere 24 that tender? to come out of the seat 25 by exerting a force on the second arm 20??. In this way (figure 5F) the pawl 20 will be? rotated so as to return to its original position so that it can once again begin an actuation cycle of the handwheel 10.

The functioning of the right actuator 11?? ? the same of the left actuator 11? described above, simply specular and therefore actuating the handwheel 10 to rotate counterclockwise.

As a function of the above, the counterclockwise rotation of the handwheel 10 allows the rotation of the threaded shaft 32, increasing the maximum light H between the limit switch defined by the latter and the rod 6a. In this way ? is it possible to increase the flow rate of the painting fluid that can? slide between rod 6a and opening 7 of the nozzle. Conversely, a clockwise rotation of the handwheel 10 reduces the maximum light H, potentially reducing this flow rate of the painting fluid to zero.

The correct assembly of the handwheel 10 ? ensured by the angular phasing means 35. The positioner 36 performs the function of keeping the seats 14 in the correct angular position with respect to the plunger 12. Instead, the set of references given by the dowel 37 and the position of the positioner 36 itself allows to mount the handwheel 10 so as to maintain a predetermined distance between rod 6a and opening 7 of the nozzle.

Clearly, the control of the actuator means 11 can be carried out at an electro-pneumatic level thanks to a control unit, not described, which interpolates the data necessary for the painting of an object by means of the painting gun 2 and which consequently regulates their activation to provide a correct flow rate of painting fluid .

From the foregoing, the advantages of the painting gun and of the painting system according to the invention are evident.

Thanks to the proposed pistol ? It is possible to autonomously adjust the flow of fluid by opening or closing the adjustment handwheel, allowing for fine, singular and fast adjustment of each single gun of a painting system.

The use of pneumatic actuators allows an automatic adjustment and no more? manual of the handwheel 10, with considerable economic advantages given the reduced maintenance time which, in the state of the art, was used to manually adjust the guns.

In addition, this invention makes it possible to simply and quickly adjust the flow rate of fluid delivered by each airbrush device, without the need to to interpose further components subject to maintenance between the color supply circuit and the gun. The presence of two actuators for each direction of rotation makes this pneumo-mechanical adjustment simplified.

The presence of seats at fixed distances allows the opening of the handwheel to be adjusted in a constant, and therefore calculable, way.

The presence of thrust means facilitates coupling between pawl and seat and therefore allows for a repetitive operation at high speeds.

Similarly, the presence of the elastic means allows a quick return of the toe to the rest position, permitting a repetitive operation at high speed.

Clearly, the proposed adjustment mechanism of the handwheel 10 allows an extremely fine adjustment of the passage between the rod 6a and the opening 7 of the nozzle which depends on the number of seats 14 made on the handwheel and the pitch of the thread of the shaft 32. In the illustrated case, comprising for example twenty seats 14 and a one millimeter thread ? It is possible to go and adjust a vertical distance of the rod of 0.05 mm by clicking on the handwheel 10, thus allowing very high precision.

Thanks to the angular timing 35 ? it is also possible to assemble and reassemble the handwheel 10 correctly without losing the correct calibration of the opening between the rod 6a and the opening 7 of the nozzle.

Finally, it is clear that modifications and variations can be made to the paint gun and to the paint system according to the present invention which however do not depart from the scope of protection defined by the claims.

For example, the type of elastic means and push means can? vary, as well as the shape of the support element, pawl or push rod and their construction materials.

Likewise, the actuating means could be electromechanical or hydraulic.

Claims (1)

1. - Paint gun (3) configured to paint an article, said paint gun (3) defining a housing (3a) extending along a longitudinal axis (A), said housing (3a) configured to house flow regulation means (6 ) suitable for regulating the passage of painting fluid coming from a source (8) of painting fluid, said painting gun (3) comprising a regulation system (9) to control the quantity? maximum paint fluid that can? be regulated by said flow regulation means (6) said flow regulation means (6) comprising a rod (6a) and an opening (7) defined by a portion of said gun (3), said rod (6a) being controlled to move with respect to said opening (7) and selectively cooperate in contact to close said opening (7) or allow the passage of said painting fluid between said opening (7a) and said rod (6a), said adjustment system (9) comprising a handwheel (10) configured to rotate around an axis (A) to vary the maximum stroke (H) of said rod (6a) with respect to said opening (7), said adjustment system (9) comprising actuator means configured to rotate said handwheel 2. - Gun according to claim 1, wherein said adjustment system (9) comprises first actuator means (11?) configured to move said handwheel (10 ) in a direction of rotation around said axis (A) and second actuator means (11??) configured to move said handwheel (10) in an opposite direction with respect to that of said first actuator means (11??), said first and second actuator means (11?, 11??) acting alternatively on said handwheel (10). 3. Gun according to Claim 1 or 2, wherein said actuator means (11) are pneumatic actuators. 4. - Gun according to one of the preceding claims, wherein the actuator means (11) comprise: - a support element (13) configured to be fixed to a support (4); - a push rod (12) carried freely for translation along an axis (C) by said support element (13); said ferrule (12) comprising a first end portion? (12a) configured to cooperate in contact with said handwheel (10) and a second end portion (12b) fluidically connected to a source (F) of pressurized fluid. 5. - Pistol according to claim 4, wherein said tip (12) ? housed movably sliding inside an opening (15) made in said support element (13), said second end portion (12b) by defining a piston sliding hermetically in said opening (15) under the action of said source (F) of pressurized fluid. 6. - Pistol according to one of Claims 4 or 5, wherein said handwheel (10) comprises a plurality of of seats (14) circumferentially arranged on said handwheel (10), said first end portion? (12a) being configured to cooperate selectively in contact with one of said seats (14) to exert a force on said handwheel (10). 7. A pistol according to claim 6, wherein said first end portion? (12a) comprises a pawl (20) hinged on said first end portion (12a) and sized to cooperate in contact with one of said seats (14). 8. - Gun according to Claim 7, comprising thrust means (23) configured to exert a force against said pawl (20) so that said pawl, in use, engages in said seat (14). 9. Gun according to one of Claims 4 to 8, comprising elastic means (17) configured to exert a force on said push rod (12) opposite to that supplied by said source (F) of pressurized fluid. 10. - Pistol according to one of the preceding claims in which said handwheel (10) comprises a fixed portion (10??) relative to said body (3a) and a movable portion (10?) around said axis (A), said portion movable (10?) carrying a threaded shaft (32) cooperating by threading with said fixed portion (10??), said threaded shaft (32) moving along an axis (A), when said movable portion (10?) ? rotated around said axis (A), varying said maximum stroke (H) of said rod (6a). 11. - Gun according to Claim 10, comprising angular adjustment means (35) configured to allow the assembly of said movable portion (10?) and said fixed portion (10??) of said handwheel (10) in a relative angular portion set. 12. - Painting system (1) for painting an article, said painting system (1) comprising at least one painting assembly (2) provided with a source (8) of painting fluid and a painting gun (3), said gun coating agent (3) being made according to any one of the preceding claims.