SPRAYING DEVICE WITH PRE-AIR CONTROL

Abstract

A spraying device with air atomization and pneumatic drive, including at least one air valve for controlling a spraying air flow through the spraying device, at least one media valve for controlling a media flow through the spraying device, at least one first pneumatically actuated drive piston for actuation of the at least one air valve and at least one second pneumatically actuated drive piston for actuation of the at least one media valve.

Claims

1. A spraying device with air atomization and pneumatic drive, comprising: at least one air valve for controlling a spraying air flow through the spraying device, at least one media valve for controlling a media flow through the spraying device, and at least one first pneumatically actuated drive piston for actuation of the at least one air valve, and at least one second pneumatically actuated drive piston for actuation of the at least one media valve.

2. The spraying device according to claim 1, wherein the at least one first drive piston and the at least one second drive piston are mechanically decoupled.

3. The spraying device according to claim 1, wherein the at least one air valve comprises a first valve seat and a first closing part, which is preferably a valve plug, that is mechanically coupled to the at least one first drive piston.

4. The spraying device according to claim 3, wherein a first preload spring that acts on the at least one first drive piston and works against the effective direction thereof, whereby the at least one first drive piston can move linearly back and forth between an idle position and an operating position, and whereby the first preload spring presses the first closing part against the first valve seat, mediated by the at least one first drive piston.

5. The spraying device according to claim 1, wherein the media valve comprises a second valve seat and a second closing part, which is preferably a valve stem, that is mechanically coupled to the at least one second drive piston.

6. The spraying device according to claim 5, wherein a second preload spring that acts on the at least one second drive piston and works against the effective direction thereof, whereby the at least one second drive piston can move linearly back and forth between an idle position and an operating position, and whereby the second preload spring presses the second closing part against the second valve seat, mediated by the at least one second drive piston.

7. The spraying device according to claim 1, wherein the at least one first drive piston and the at least one second drive piston are arranged along a common longitudinal axis, acting in opposing effective directions.

8. The spraying device according to claim 1, wherein the at least one first drive piston and the at least one second drive piston are arranged along different longitudinal axes, acting in different effective directions.

9. The spraying device according to claim 1, wherein a first piston chamber associated with the at least one first drive piston and a second piston chamber associated with the at least one second drive piston and are directly fluidly connected to one another and have a common control air supply.

10. The spraying device according to claim 9, wherein there is a flow restriction in the fluid connection between the first piston chamber and the second piston chamber.

11. The spraying device according to claim 10, wherein the flow restriction is formed by a second throttle check valve.

12. The spraying device according to claim 7, wherein a first piston chamber associated with the at least one first drive piston and a second piston chamber associated with the at least one second drive piston are formed by a common piston chamber having a common control air supply.

13. The spraying device according to claim 6, wherein a first preload spring that acts on the at least one first drive piston and works against the effective direction thereof, whereby the at least one first drive piston can move linearly back and forth between an idle position and an operating position, and whereby the first preload spring presses the first closing part against the first valve seat, mediated by the at least one first drive piston and wherein the first preload spring and the second preload spring are designed such that the first preload spring in the idle position pushes against the at least one first drive piston with a lower preload than that applied by the second preload spring in the idle position pushing against the at least one second drive piston.

14. The spraying device according to claim 13, wherein the first preload spring has a lower spring constant than the second preload spring.

15. The spraying device according to claim 9, wherein there is a first throttle check valve upstream of the first piston chamber on the inlet side.

16. The spraying device according to claim 1, wherein there are at least two air valves for controlling a spraying air flow through the spraying device, wherein there are at least two first pneumatically actuated drive pistons for actuation of the at least two air valves.

17. The spraying device according to claim 1, wherein there are at least two media valves for controlling a media flow through the spraying device, wherein there are at least two second pneumatically actuated drive pistons for actuation of the at least two media valves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Further characteristics and advantages of the invention are explained in the following with the aid of the example embodiments depicted in the figures. The following are shown:

[0045] FIG. 1 shows a first embodiment of the spraying device in the idle position in a lateral sectional view;

[0046] FIG. 2 shows the first embodiment of the spraying device in an intermediate position in a lateral sectional view;

[0047] FIG. 3 shows the first embodiment of the spraying device in the operating position in a lateral sectional view;

[0048] FIG. 4 shows a second embodiment of the spraying device in the idle position in a lateral sectional view;

[0049] FIG. 5 shows a third embodiment of the spraying device in the idle position in a lateral sectional view;

[0050] FIG. 6 shows the third embodiment of the spraying device in the idle position in a top sectional view;

[0051] FIG. 7 shows the third embodiment of the spraying device in an intermediate position in a lateral sectional view;

[0052] FIG. 8 shows the third embodiment of the spraying device in the intermediate position in a top sectional view; and

[0053] FIG. 9 shows the third embodiment of the spraying device in the operating position in a lateral sectional view.

DETAILED DESCRIPTION OF THE INVENTION

[0054] The first example embodiment of the spraying device according to the invention will be explained with the aid of FIGS. 1 through 3. This is a spraying device with air atomization, wherein the medium is primarily atomized via a high media pressure through a small media opening (airless). A secondary air atomization supports the primary airless atomization and improves the spray jet geometry, which is explained next.

[0055] FIGS. 1 through 3 are sections in the same plane; therefore, lines for the medium, control air, or spraying air, specifically for the atomizing air or shaping air, are only shown in part or are not shown at all where they are partially or completely located in other planes.

[0056] Orientation and direction information, such as “in front of,” “behind,” “rearward,” or “longitudinal” is always relative to the direction of discharge of the medium. For example, the nozzle is thus always “in front” in relation to the housing of the device.

[0057] The spraying device 10 comprises a housing 12 that spans along a longitudinal axis A. The housing is a three-part design, and it comprises a front housing part 14, a rear housing part 16, and a housing cover 18 for closure of the rear end of the rear housing part. The three-part design facilitates access to the interior components for simplification of assembly, maintenance, and repair. On the front end of the front housing part 14, there is a nozzle 20, through which the medium to be applied exits and by means of which it is atomized and discharged in the direction of the surface to be coated. The nozzle 20 comprises for this a central media opening 22 for the medium. The geometry of the media opening 22 and in particular the opening cross-section are dimensioned such that in coordination with the media pressure, the medium will be primarily atomized immediately after discharge from the media opening. The nozzle 20 also has feed channels 24 for atomizing air, which meets the media mist immediately after the primary atomization. The atomizing air thus supports the atomization and directs the media mist generated as a spray jet with a desired geometry in the direction of the object to be coated.

[0058] The spraying device 10 comprises an air valve 102 in the housing 12 for controlling a spraying air flow. The air valve 102 has a first closing part 106 and a first valve seat 108. The closing part 106 is formed by a conical section whose surface lies against the corresponding first valve seat 108, which is formed by an annular bore step in the housing 12 of the spraying device. A first pneumatically actuated drive piston 110 with a piston surface 111 is mechanically coupled to the closing part 106 for actuation of the air valve. The coupling is manifested in this case by the first closing part 106 being formed as a one-piece component together with the first drive piston 110. The first drive piston 110 is located and guided in a cavity in the housing 12 along the longitudinal axis A such that it is movable forward and rearward.

[0059] The spraying device 10 comprises also a media valve 112 in the housing 12 for (binary) controlling a media flow. The media valve 112 has a second closing part 116 and a second valve seat 118. The second closing part 116 is formed by a valve stem, which spans along the longitudinal axis concentrically to and through the direction of movement of the first drive piston 110, and which has at its front end a spherical-cap-shaped sealing surface and a sealing ring 120 that lies against the corresponding second valve seat 118. The geometry of the media opening 22 is responsible for the primary atomization. The media valve 112 is thus moved rearward into the housing interior relative to the media opening 22 and is able to quickly release the maximum cross-section of the media stream due to the spherical-cap shape. The second valve seat 118 is formed as a counterbore at the inlet opening 124 of a borehole 126, through which the medium is guided to the nozzle 20 when the media valve 112 is open. A second pneumatically actuated drive piston 130 with a piston surface 131 is mechanically coupled to the second closing part 116 for actuation of the media valve 112. Coupling occurs via a central bolt 132 via which the valve stem is connected at its rear end to the second drive piston 130 via positive mechanical engagement. The second drive piston 130 is also located and guided in a cavity in the housing 12 along the longitudinal axis A such that it is movable forward and rearward. The first drive piston 110 and the second drive piston 130 are thus arranged along the common longitudinal axis A, acting in opposing directions.

[0060] A common piston chamber 133 is formed between the piston surfaces 111, 131 of the two drive pistons 110 and 133. Said piston chamber simultaneously forms the first piston chamber, associated with the first drive piston, and the second piston chamber, associated with the second drive piston. The piston chambers are thereby naturally directly fluidly connected to one another and have a common control air supply, symbolized by arrow 134.

[0061] Furthermore, in the housing 12 is a first preload spring 136, which acts on the first drive piston 110 against the effective direction thereof. The preload spring 136 is designed as a helical compression spring, which can be located inside the first drive piston 110 in a space-saving manner. The first drive piston 110 is shown in FIG. 1 in an idle position, in which the first preload spring 136 is pressing the first closing part 106 against the first valve seat 108, mediated by the first drive piston 110. Because the first preload spring 136 is effective rearward and the first drive piston 110 is effective forward, it is possible, in contrast to the prior art, to simultaneously realize a large piston surface area 111 and a large flow cross-section when the air valve 102 is open.

[0062] In the same way, in the housing 12 is a second preload spring 138, which acts on the second drive piston 130 against the effective direction thereof. The preload spring 138 is likewise designed as a helical compression spring, which likewise can be located inside the second drive piston 130 in a space-saving manner. The second drive piston 130 is also shown in FIG. 1 in an idle position, in which the second preload spring 138 is pressing the second closing part 116 against the second valve seat 118, mediated by the second drive piston 130. Because the first and second drive pistons 110, 130 are effective in opposite directions, the preload springs 136, 138 are effective in opposite directions. The first preload spring 136 has a lower spring constant than the second preload spring 138. The difference between the preloads is selected such that the first preload spring in the idle position pushes against the first drive piston with a lower preload than that applied by the second preload spring in idle position pushing against the second drive piston. Because the piston surfaces 111, 131 only have a small size differential in the embodiment shown, it is thereby ensured that the first drive piston 110 will move first and that the air valve 102 will open before the media valve 112 opens.

[0063] While the valves 102 and 112, as described previously, are closed in FIG. 1, the supply lines upstream of the valves 102 and 112 have spraying air under pressure on one side, symbolized by arrow 140, and the medium under pressure on the other side, symbolized by arrows 142. Startup of the spraying device 10 occurs via the pressurization of the common piston chamber 133 with control air 134, wherein the first occurrence is that the first drive piston 110 is driven against the first preload spring 136, thus opening the coupled air valve 102, as depicted in FIG. 2. In the intermediate position shown here, the first drive piston 110 is already displaced to its maximum stroke in the forward direction, and therefore the air valve 102 is already fully open, while the higher preload of the second preload spring 138 keeps the media valve 112 fully closed. In the intermediate position, the spraying air, symbolized by arrow 144, flows through the spraying device 10, referred to at this point in time as pre-air, symbolized by arrow 146, and exits the nozzle 20 without medium. If the pressure of the control air 134 further increases in the piston chamber 133, the second drive piston 130 will be driven against the second preload spring 138 and the coupled media valve 112 will open, as depicted in FIG. 3. In the operating position shown here, both drive pistons 110 and 130 are displaced to their maximum stroke to the front or rear, respectively, such that the air valve 102 and the media valve 112 are completely open. In the operating position, the spraying air, symbolized by arrow 144, and the medium, symbolized by arrow 142, flow through the spraying device 10 and simultaneously exit the nozzle 20, symbolized by the arrows 146 and 148, wherein the medium is atomized and is directed toward the object to be coated. When terminating the spraying process, the media valve 112 and the air valve 102 are closed in the opposite order so that a post-air is discharged from the nozzle in the intermediate position, which blows the nozzle clean of media residue.

[0064] The second example embodiment of the spraying device according to the invention will be explained with the aid of FIG. 4. Here as well, the lines for the medium or the spraying air, or specifically for the atomizing air, control air, and shaping air, are only shown in part or are not shown at all where they are partially or completely located in other planes.

[0065] The spraying device 30 according to the second example embodiment has, analogous to the first example, first and second drive pistons along a common longitudinal axis, acting in opposing effective directions, each with associated valves and preload springs. It is different from the first example embodiment primarily in terms of the dimensioning of the components as well as a differing nozzle geometry. Therefore, the following description will essentially only consider the differences, while the preceding description of the first example embodiment is otherwise referred to.

[0066] The spraying device 30 according to FIG. 4 is an embodiment that only works with the assistance of air atomization; that is, unlike the example embodiment according to FIGS. 1 through 3, it does not atomize primarily “airlessly.” The spraying device 30 comprises in particular a nozzle 32 at the front end, which differs from the nozzle 20 in that the atomizing air exits through an annular mouth of an annular feed channel 36, wherein the mouth is concentrically around the media opening 34 for the medium. The channel structure inside the housing 38 has corresponding design differences.

[0067] The nozzle 32 is also different from the nozzle 20 in terms of the media supply. The medium is supplied through a media connection 39 under a relatively low overpressure (12 bar maximum), wherein a different media valve 212 and different cross-sections for the lines inside the housing 38 are necessary. This media valve 212 is also designed as a needle valve. It has a second closing part 216 in the form of a valve stem and a second corresponding valve seat 218. However, the tip of the valve stem is a conical tapered point in this case, and it enters a conical borehole of the same conical dimensioning in a form-fitting manner without an additional sealing element when the media valve 212 is closed. The sealing surface of the valve seat 218 also transitions directly to the central media opening 34, through which the medium discharges without atomization. With this construction, it is possible to set the media flow as required via an adjustable end position of the valve stem relative to the valve seat 218. The second pneumatically actuated drive piston 230 is likewise mechanically coupled to the second closing part 216, for example by a threaded connection, for actuation of the media valve 212.

[0068] The third example embodiment of the spraying device according to the invention will be explained with the aid of FIGS. 5 through 9. These show sections in two planes that are perpendicular to each other. Here as well, the lines for the medium or the spraying air, or individually for the atomizing air, control air, and shaping air, are only shown in part or are not shown at all where they are partially or completely located in other planes.

[0069] The spraying device 40 comprises a housing 42 that spans along a longitudinal axis A. The housing is a four-part construction and comprises a front housing part 44, a rear housing part 46, an adapter 47 connected lateral to the front and rear housing parts 44, 46 relative to the longitudinal axis A, and a housing cover 48 for closing off the rear end of the rear housing part 46. On the front end of the front housing part 44, there is a nozzle 50, through which the medium to be applied exits and by means of which it is atomized and discharged in the direction of the surface to be coated. The nozzle 50 comprises for this a central media opening 52 for the medium. The nozzle 50 also has an annular mouth of an annular feed channel 54, the annular mouth being concentrically around the media opening 52, and being the component out of which the atomizing air escapes, and which atomizes the escaping medium and directs the media mist generated thereby as a spray jet in the direction of the object to be coated. There are also shaping air channels, not shown, that are separate from the feed channel 54 and that open into two horns 56, which are mirrored opposite one another relative to the longitudinal axis A. The shaping air exits the horn mouths 58 at an acute angle to the longitudinal axis and then meets and shapes the spray jet. This spraying device 40 is used in a robotic system with air atomization and separate shaping air for automatic applications.

[0070] The spraying device 40 comprises an air valve 302 in the adapter 47 of the housing 42 for controlling a spraying air flow 340. The air valve 302 has a first closing part 306 and a first valve seat 308. The closing part 306 is formed by a conical section whose surface lies against the corresponding first valve seat 308, which is formed by an annular bore step in the adapter 47 of the spraying device. A first pneumatically actuated drive piston 310 with a first piston surface 311 is mechanically coupled to the closing part 306 for actuation of the air valve. The coupling is manifested in this case by the first closing part 306 being formed as a one-piece component together with the first drive piston 310. The first drive piston 310 is located and guided in a cavity in the adapter 47 perpendicular to the longitudinal axis A such that it can move back and forth. A first piston chamber 313 is associated with the first drive piston 310 and forms a variable part of the cavity delimited by the first piston surface 311.

[0071] The spraying device 40 comprises also a media valve 312 in the housing 42 for controlling a media flow 342. This media valve 312 is also designed as a needle valve than spans along the longitudinal axis A. It has a second corresponding valve seat 318 and a second closing part 316 in the form of a valve stem. Like in the second example, the tip of the valve stem is a conical tapered point, and it mates with the second valve seat 318, which is a conically tipped borehole of the same conical dimensioning, in a form-fitting manner without an additional sealing element when the media valve 312 is closed. The sealing surface of the valve seat 318 again transitions directly to the central media opening 52. A second pneumatically actuated drive piston 330 with a second piston surface 331 is mechanically coupled to the second closing part 316 for actuation of the media valve 312. Coupling occurs via a central bolt 332, via which the valve stem is connected at its rear end to the second drive piston 330 via positive mechanical engagement. The second drive piston 330 is located and guided in a cavity in the rear housing part 46 of the housing 42 along the longitudinal axis A such that it is movable forward and rearward. A second piston chamber 333 is associated with the second drive piston 330 and forms a variable part of the cavity delimited by the piston surface 331.

[0072] In contrast to the first example, the first drive piston 310 and the second drive piston 330 are not coaxially arranged. Nevertheless, the first piston chamber 313, associated with the first drive piston 310, and the second piston chamber 333, associated with the second drive piston 330, are directly fluidly connected to one another and to a common control air supply 352 via a connecting line 350, referred to here also as a fluid connection. In the fluid connection 350 between the first piston chamber 313 and the second piston chamber 333 is a flow restriction in the form of the connecting line 350 itself. Because this constitutes a cross-sectional reduction with respect to the cross-sections of the piston chambers 313 and 333, it effects a pressure drop along its length, such that pressure builds up more slowly in the second piston chamber 333 than in the first piston chamber 313. There can also be a second throttle check valve in this location instead of a cross-sectional reduction.

[0073] Furthermore, in the adapter 47 of the housing 42 is a first preload spring 336, which acts on the first drive piston 310 against the effective direction thereof. The preload spring 336 is designed as a helical compression spring, which can be located inside the first drive piston 310 in a space-saving manner. The first drive piston 310 is shown in FIG. 6 in an idle position, in which the first preload spring 336 is pressing the first closing part 306 against the first valve seat 308, mediated by the first drive piston 310. Here as well, the first preload spring 336 and the first drive piston 310 are in opposition, whereby a large piston surface area 311 and a large flow cross-section are simultaneously possible with an open air valve 302.

[0074] In the same way, in the housing part 46 of the housing 42 is a second preload spring 338, which acts on the second drive piston 330 against the effective direction thereof. The preload spring 338 is likewise designed as a helical compression spring, which can be located inside the second drive piston 330 in a space-saving manner. The second drive piston 330 is also shown in FIG. 5 in an idle position, in which the second preload spring 338 is pressing the second closing part 316 against the second valve seat 318, mediated by the second drive piston 330.

[0075] The first preload spring 336 has a lower spring constant than the second preload spring 338. The first preload spring 336 and the second preload spring 338 are designed such that the first preload spring 336 in the idle position presses against the first drive piston 310 with a lower preload than that of the second preload spring 338 in the idle position pressing against the second drive piston 330, and to such a degree that considering the size difference between the first and second piston surface areas 311, 331, and considering where applicable a pressure loss across the connecting line 350, the first drive piston 310 is moved first, and the air valve 302 opens before the media valve 312.

[0076] In contrast to all previous examples, there is also a second air valve 362 in the adapter 47 of the housing 42 for separate control of a shaping air flow. The second air valve 362 has a mirror-image construction to the air valve 302 in the view of FIG. 6. The second air valve 362 accordingly has another first closing part 366 and another first valve seat 368. The closing part 366 is formed by a conical section whose surface lies against the corresponding valve seat 368, which is formed by an annular bore step in the adapter 47 of the spraying device 40. Accordingly, another first pneumatically actuated drive piston 370 with a piston surface 371 is mechanically coupled to the closing part 366 for actuation of the second air valve 362. Coupling is manifested, as in the case of the first drive piston 310 with the air valve 302, by the first closing part 366 being formed as a one-piece component together with the first drive piston 370. The first drive piston 370 is also located and guided perpendicular to the longitudinal axis A in a cavity in the adapter 47 such that it is movable back and forth in the opposite direction as the first drive piston 310. The same first piston chamber 313 as the first drive piston 310 is associated with the first drive piston 370.

[0077] Also analogous is another first preload spring 376, which acts on the first drive piston 370 against the effective direction thereof. The preload spring 376 is designed as a helical compression spring, which can be located inside the first drive piston 370 in a space-saving manner. The first drive piston 370 is shown in FIG. 6, like the first drive piston 310, in an idle position, in which the preload spring 376 presses the closing part 366 against the valve seat 368, mediated by the first drive piston 370. Here as well, the preload spring 376 and the first drive piston 370 are in opposition, whereby a large piston surface 371 and a large flow cross-section are simultaneously possible with an open second air valve 362. The preload spring 376, with a piston surface 371 of the same size and a common first piston chamber 313, is designed, like preload spring 336, such that the first drive piston 370 is moved at the same time as the first drive piston 310 and before the second drive piston 330, so that the second air valve 362 opens at the same time as the air valve 302 before the media valve 312.

[0078] At the inlet side, that is, between the first piston chamber 313 and the control air supply 352, there is also a first throttle check valve 378 upstream of the first piston chamber 313 in the adapter 47. The first throttle check valve 378 allows the control air to flow into the first piston chamber 313 unthrottled, but it then throttles the control air upon venting, such that a dynamic pressure forms in the first piston chamber upon venting. An asymmetry thus develops between the pressure increase and the pressure decrease.

[0079] While the valves 302, 312, and 362, as described previously, are closed in FIGS. 5 and 6, the supply lines have atomizing air, symbolized by arrow 340, or shaping air, symbolized by arrow 341, upstream of the valves 302 and 362, and the medium on the other side, symbolized by arrow 342, all of which are pressurized. Startup of the spraying device 40 occurs via the pressurization of the piston chambers 313 and 333 with control air 334, wherein the first occurrence is that the first drive pistons 310, 370 are driven against the respective first preload springs 336, 376, thus opening the air valves 302, 362, as illustrated in FIGS. 7 and 8. In the intermediate position shown here, the first drive pistons 310, 370 are each already displaced to their maximum stroke so that the air valves 302, 362 are completely open while the higher preload of the second preload spring 338 still maintains the media valve 312 closed upon a simultaneous potential pressure decrease in the connecting line 350. In the intermediate position, the atomizing air, symbolized by arrow 340, and the shaping air, symbolized by arrow 341, flows through the spraying device 40 and at this point in time exits the nozzle as pre-air without medium. If the pressure of the control air 334 further increases in the piston chamber 333, the second drive piston 330 will be driven against the second preload spring 338 and the coupled media valve 312 will open, as depicted in FIG. 9. In the operating position shown here, all three drive pistons 310, 330, and 370 are displaced to their maximum stroke to the side or rear, respectively, so that the air valves 302, 362 and the media valve 312 are completely open. In the operating position, the atomizing air, symbolized by arrow 340, the shaping air (not shown in FIG. 9), and the medium, symbolized by arrow 342, flow through the spraying device 40 and simultaneously exit the nozzle 50, wherein the medium is atomized and is directed toward the object to be coated in the set shape of the spray jet. When terminating the spraying process, the media valve 312 and the air valves 302, 362 are closed in the opposite order so that in the intermediate position, a post-air, comprising atomizing air and shaping air, is discharged from the nozzle, which blows the nozzle clean of media residue. The aforementioned asymmetry between the pressure increase and the pressure decrease in the first piston chamber 313 extends the post-air duration.

[0080] As is seen in the preceding example, the invention provides for a powerful spraying device whose drive exhibits both efficiency and low susceptibility to wear due to lower stress on the individual components. The spraying device also requires fewer components than the prior art. It is therefore advantageous in terms of both service life and maintenance.

TABLE-US-00001 Reference designations 10 Spraying device 12 Housing 14 Front housing part 16 Rear housing part 18 Housing cover 20 Nozzle 22 Media opening 24 Feed channel 30 Spraying device 32 Nozzle 34 Media opening 36 Feed channel 38 Housing 39 Media connection 40 Spraying device 42 Housing 44 Front housing part 46 Rear housing part 47 Adapter 48 Housing cover 50 Nozzle 52 Media opening 54 Feed channel 56 Horn 58 Horn mouth 102 Air valve 106 First closing part 108 First valve seat 110 First drive piston 111 Piston surface 112 Media valve 116 Second closing part 118 Second valve seat 120 Sealing ring 124 Inlet mouth 126 Borehole 130 Second drive piston 131 Piston surface 132 Bolt 133 Piston chamber 134 Arrow: Control air 136 First preload spring 138 Second preload spring 140 Arrow: Spraying air 142 Arrow: Medium 144 Arrow: Spraying air 146 Arrow: Spraying air 148 Arrow: Medium 212 Media valve 216 Second closing part 218 Second valve seat 230 Second drive piston 302 Air valve 306 First closing part 308 First valve seat 310 First drive piston 311 First piston surface 312 Media valve 313 First piston chamber 316 Second closing part 318 Second valve seat 330 Second drive piston 331 Second piston surface 332 Bolt 333 Second piston chamber 334 Control air 336 First preload spring 338 Second preload spring 340 Spraying air flow 342 Media flow 350 Connecting line 352 Control air supply 362 Second air valve 366 Additional first closing part 368 Additional first valve seat 370 Additional first drive piston 371 Piston surface 376 Additional first preload spring 378 Throttle check valve