Material quantity control device for limiting the material needle stroke of a spray gun, spray gun with a material quantity control device, and method for applying a coating material

Abstract

To provide a material amount control device of a spray gun, the spray gun, and a coating method.SOLUTION: Wherein the spray gun can be fitted with the material quantity control device (1) and has a front end with a holding means (5) in the form of a thread (14), an opposite rear end, a stop surface (7) for limiting the material needle stroke in interaction with a corresponding counter-piece of the spray gun, and adjustment means (8) by means of which the axial position of the stop surface can be adjusted in order to limit the material needle stroke without changing the axial position of the stop surface and without removing the material quantity control device, and a quick-adjustment mechanism (10), the position of which is adjustable relative to the adjusting means between a stroke-limiting position and a stroke-releasing position, wherein the stop face, at least in the stroke-limiting position, is arranged axially at the level of the retaining means or is arranged offset relative to the retaining means in the direction of the rear end of the device for controlling the quantity of material.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a material quantity control device for limiting a material needle stroke of a spray gun, the device having a front end with a holding means by which the material quantity control device can be attached to the spray gun, a rear end opposite the front end, a stop surface for limiting the material needle stroke, an adjustment means by which the axial position of the stop surface can be adjusted relative to the spray gun to limit the material needle stroke by interacting with a corresponding part of the spray gun, and a quick adjustment mechanism by which the position of the stop surface can be adjusted axially rearward and forward relative to the adjustment means between a stroke limiting position and a stroke open position different from the stroke limiting position without changing the adjustment of the adjustment means (8) and without removing the material quantity control device from the spray gun.

[0002] The present invention further relates to a spray gun for discharging a coating material, having a material needle and a material quantity control device for limiting the material needle stroke, as well as to a method for applying a coating material with a spray gun. [Background technology]

[0003] Material quantity control devices are used, for example, in the field of painting technology, and serve to provide a stop, via a stop surface, for the end of a material needle that controls the material discharge amount, facing away from the material discharge direction. Typically, the material quantity control device is attached to the end of the spray gun that faces away from the material nozzle of the spray gun in the material discharge direction. This attachment is usually achieved via an internally threaded hole in the body of the spray gun. The material quantity control device has a corresponding external thread and is screwed into the hole. By changing the screw-in depth of the material quantity control device, the stop of the material quantity control device can be displaced axially backward and forward, thereby limiting the maximum material needle stroke of the material needle to a greater or lesser extent.

[0004] For some applications or with certain coating materials, it is desirable to limit the material discharge amount, for example to achieve a special surface effect. For other applications, it is necessary to be able to discharge the maximum amount of material. For this purpose, it is preferable to be able to quickly switch between both positions backward and forward. Such a switchable material quantity control device is known from JP 4-126562 A.

[0005] JP 4-126562 A describes a material quantity control device that can be switched backward and forward between a fully open position and a half-open position. It is intended to enable non-skilled workers to achieve high surface quality. This is intended to be achieved by applying multiple layers of equal thickness in the half-open position, rather than the usual single layer applied in the fully open position. Skilled workers are intended to apply multiple layers of equal thickness in the half-open position for small or rough surfaces. To switch, the rear end of the material quantity control device slides forward in the material discharge direction, then rotates 90° and slides backward again.

[0006] This type of solution satisfies the need for rapid forward and backward switching between a first stop surface position and a second stop surface position. However, due to its design, the material quantity control device protrudes significantly and cannot be installed on a conventional spray gun without modification. Furthermore, when the material quantity control device is removed, the end of the material needle remains hidden within the gun body of the spray gun, making it difficult to remove. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 4-126562 [Patent Document 2] U.S. Patent No. 2,082,061 [Patent Document 3] Japanese Patent Application Publication No. 2016-098884 [Patent Document 4] German Patent No. 102007018339 [Patent Document 5] U.S. Patent No. 2,904,262 Summary of the Invention [Problem to be solved by the invention]

[0008] In light of the above-described prior art, it is an object of the present invention to provide a material needle control device with a compact design, a spray gun with a corresponding material needle control device, and a corresponding method for applying coating material using a quickly adjustable material quantity control device. [Means for solving the problem]

[0009] The material quantity control device can be used in a spray gun substantially consisting of a body having a gun grip, a nozzle head, a trigger guard, and a material guiding system, the material guiding system including a material needle and a material quantity control device for adjusting a maximum material needle stroke, and capable of determining the amount of material to be dispensed.Similarly, this may be an automatic spray gun that does not have a gun grip and a trigger, and is automatically operated by a release mechanism.

[0010] Such spray guns can be pressure-atomized or air-atomized. In pressure-atomized spray guns, the material to be atomized is placed under high pressure, and atomization occurs through interaction with ambient air as the material exits the nozzle opening under high pressure. Air-atomized spray guns additionally include an air supply connection to which a compressed air supply can be connected, a compressed air passage for guiding the compressed air, an air guide system with an air valve, and an air quantity control device for regulating the amount of compressed air. In air-atomized spray guns, the compressed air required for atomization is supplied by the air supply connection, which is located on or inside the gun grip. The trigger guard is operated to a first pressure point, opening the air valve. Further pulling of the trigger guard further withdraws the material needle from the nozzle. The coating agent then flows out of the material nozzle as a result of gravity or a pressure difference, is atomized by compressed air flowing through an air nozzle configured in the form of an annular gap surrounding the material nozzle, and is carried in the material discharge direction to the object to be coated, on which the material is deposited to form a coating film.

[0011] The nozzle head of such a spray gun has a material guide area through which the material to be atomized flows from the coating agent inlet to the material nozzle. The coating agent inlet is provided with a material supply, which can be provided, for example, in the form of a storage container or in the form of a lead-in pipe from an external material store. Typical storage containers are, for example, flow cups, suction cups, or side cups. The pressure difference required for material delivery is generated, for example, by gravity or by a material delivery device that places the material to be delivered under pressure. Material delivery can also be achieved by negative pressure, whereby negative pressure is generated by air flowing past the material nozzle, which causes the material to be sucked in.

[0012] Such spray guns offer users multiple adjustment possibilities. The air flow rate can be adjusted using an air volume control device. The round jet control / wide jet control allows for the change of the jet shape of the aerosol discharged from the spray gun. To achieve this, two or more horns are provided with horn air nozzles in the nozzle head, which are diametrically opposed relative to the material nozzle. The horn air nozzles face inward toward the coating agent jet being discharged. When no air flow is discharged from the horn air nozzle, the coating agent jet can diffuse evenly in all directions after being discharged from the nozzle, resulting in a circular material jet shape in cross section. When air is discharged from the horn air nozzle, the coating agent jet will have an elliptical material jet shape in cross section after being discharged from the material nozzle.

[0013] The material quantity control device defines one side of the path along which the material needle can move along its own axis. On the opposite side, this path is defined by the material nozzle. The greater the displacement of the stop surface of the material quantity control device in the material discharge direction, the shorter the path along which the material needle can move when the trigger guard is operated, thereby limiting the maximum material volume flow rate. With the trigger guard not operated, the material needle is held in the material nozzle by a compression spring, thereby sealing it. When the trigger guard is operated, the material needle moves out of the material nozzle, gradually releasing it.

[0014] The present invention proposes a material quantity control device for limiting a material needle stroke of a spray gun, preferably a handheld type. The material quantity control device has a front end with a retaining means, particularly in the form of a screw thread, by which the material quantity control device can be attached to the spray gun. A rear end faces the front end. The material quantity control device further has a stop surface for limiting the material needle stroke and an adjustment means formed by a part of the retaining means, particularly in the form of a screw thread, via which the axial position of the stop surface for limiting the material needle stroke can be adjusted relative to the spray gun through interaction with a corresponding part of the spray gun. The material quantity control device also has a quick adjustment mechanism by which the stop surface can be axially adjusted backward and forward relative to the adjustment means between a stroke limiting position and a stroke open position different from the stroke limiting position. This does not change the adjustment of the adjustment means or the axial position of the stop surface adjusted by the adjustment means, and the material quantity control device does not have to be removed from the spray gun. The stop surface is arranged axially at the level of the holding means or axially offset relative to the holding means toward the rear end of the material quantity control device, at least in the stroke limit position. Without the material quantity control device being removed is understood to mean that the material quantity control device is not removed from the spray gun but remains connected thereto. In the stroke limit position, the stop surface is preferably closer to the front end of the material quantity control device than in the stroke open position. This configuration of the material quantity control device allows for a particularly compact design, which simplifies handling by the user.

[0015] The open stroke position is understood to be the position of the material quantity control device in which the stop surface does not restrict or only slightly restricts the axial movement of the material needle of the spray gun when the coating material is being discharged. Accordingly, the trigger guard of the spray gun can be operated up to the position where the maximum amount is discharged. The stroke limit position is understood to be the position of the material quantity control device in which the stop surface of the material quantity control device restricts the axial movement of the material needle of the spray gun, allowing the material needle of the spray gun to be displaced axially in the direction opposite to the material discharge direction only to the extent that a reduced amount of coating material can be discharged compared to the maximum amount of coating material in the open stroke position. The amount of coating material that can be discharged in the stroke limit position is preferably more than one-third, and more preferably more than half, of the coating material that can be discharged in the open stroke position. It is particularly preferred that more than two-thirds, preferably more than 80%, of the maximum amount of material can be discharged in the stroke limit position.

[0016] In another preferred embodiment, the material quantity control device has a front end and a rear end opposite the front end, the front end having a holding means and an adjustment means, the adjustment means extending from the front end to the rear end. Furthermore, a stop surface for limiting the material needle stroke and a quick adjustment mechanism separate from the adjustment means are provided, by which the stop surface can be axially adjusted rearward and forward relative to the holding means between a stroke limiting position and a stroke open position different from the stroke limiting position. In this case, the stop surface is axially arranged at the same level as the holding means, or axially offset from the holding means toward the rear end of the material quantity control device, at least when in the stroke limiting position. In this design, the stop surface is offset rearward relative to the adjustment means, which also allows for a particularly compact design, which simplifies handling by the user.

[0017] In a particularly preferred embodiment, the stop surface is axially at the level of the adjusting means, at least in the stroke limit position, or is axially offset relative to the adjusting means toward the rear end of the material quantity control device, preferably closer to the rear end than the front end of the material quantity control device. Additionally, the material quantity control device may also be at the level of the adjusting means, or be axially offset relative to the adjusting means toward the rear end of the material quantity control device, preferably closer to the rear end than the front end of the material quantity control device, even in the stroke open position. This embodiment has the advantage that the stop surface for the material needle of the spray gun slides further rearward, thereby further shortening the required length of the material quantity control device, which leads to a more compact design. Preferably, the material quantity control device is configured so that, when the trigger guard is pulled, the material needle of the spray gun extends into the material quantity control device over at least half of its length, preferably over at least two-thirds of its length.

[0018] It is particularly preferred that the material quantity control device has a hollow space extending from the front end of the material quantity control device toward the rear end thereof into the material quantity control device, the hollow space being configured to accommodate a material needle of a spray gun. The hollow space described above increases the space available inside the material quantity control device for the material needle of the spray gun, which leads to a more compact design of the material quantity control device.

[0019] Preferably, the material quantity control device is configured such that, in the stroke limit position, the stop surface is located axially closer to the front end of the material quantity control device than in the stroke open position. In this case, the stop surface is preferably positioned within the half of the material quantity control device that includes the rear end of the material quantity control device in the stroke limit position. Since the stop surface is particularly far away at the rear end of the material quantity control device even in the stroke limit position, a particularly compact design is possible.

[0020] In a further particularly preferred embodiment, a locking means is provided, by means of which the material quantity control device can be axially locked relative to the spray gun in the position adjusted by the adjusting means, the locking means preferably being configured as a counter nut, thereby reducing the risk of unintentional displacement of the adjusting means.

[0021] Preferably, the material quantity control device has an adjustment element, particularly a sleeve-shaped adjustment element, including the adjustment means. Furthermore, preferably, a stop element, particularly a sleeve-shaped stop element, including a stop surface is provided. The stop element and the adjustment element are preferably axially displaceable relative to each other. The stop surface, and preferably the entire stop element, are supported so as to be axially slidable relative to the adjustment element between a stroke limiting position and a stroke open position.

[0022] It is particularly preferred that the stop member is at least partially arranged inside the adjusting member and / or the adjusting member is at least partially arranged inside the stop member. The nested design results in a particularly compact material quantity control device that requires particularly few parts and provides a large internal space for accommodating the material needle of the spray gun.

[0023] In another particularly preferred embodiment, the stop element and the adjustment element each have a shoulder that abuts against one another in the open stroke position, which creates a particularly simple maximum stop for the open stroke position without the need for additional parts.

[0024] Preferably, the material quantity control device is configured so that the position of the stop surface is adjusted by the quick adjustment mechanism, preferably only by this mechanism, by axial movement of the stop surface, and / or so that the position of the stop surface is adjusted by the adjusting means by a screw movement about the central axis of the material quantity control device. The above-mentioned adjustment movements allow for particularly easy operation of the quick adjustment mechanism and particularly precise operation of the adjusting means.

[0025] Particularly preferably, the quick adjustment mechanism is configured to automatically lock in the stroke limit position and / or the stroke open position, thereby automatically securing the quick adjustment mechanism against resetting, which improves the functional reliability of the quick adjustment mechanism.

[0026] Preferably, the quick adjustment mechanism includes a locking element that serves to lock the quick adjustment mechanism in the stroke limiting position and / or the open stroke position, and that preferably at least partially surrounds the adjustment element and / or the stop element in the circumferential direction. The locking element prevents automatic adjustment from the selected open stroke or stroke limiting position.

[0027] In a particularly preferred embodiment, the quick adjustment mechanism automatically transitions from the stroke limiting position to the stroke open position when the locking member is retracted. Automatic adjustment from the stroke limiting position to the stroke open position is achieved by a force generated by a spring member that preferably acts on the stop member axially away from the front end of the material quantity control device. This can be achieved by a spring member internal to the material quantity control device or a spring member internal to the spray gun that slides the material needle back into the sealing seat of the material valve when the material valve is opened.

[0028] In another particularly preferred embodiment, the material quantity control device has a sleeve-shaped adjusting element and a sleeve-shaped stop element that is arranged inside the adjusting element in a partial area and is coaxially supported on the inner surface of the sleeve-shaped adjusting element.

[0029] In a particularly preferred development, the adjustment element is provided with an external thread that constitutes the holding means and the adjustment element. A locking means in the form of a counter nut can be provided on the external thread. The axial position of the stop surface in the stroke limit position and the stroke open position can be adjusted via the adjustment element by means of the thread.

[0030] In another embodiment, the stop element can be closed at its end opposite the front end of the quantity control device, with a stop surface formed on the inside of the closed end.

[0031] In a preferred development of the invention, the outer surface of the stop element can be provided with a shoulder in the region of its open end opposite the closed end, which shoulder abuts against a shoulder on the inner surface of the adjusting element when the inner stop element is in the open stroke position with its maximum sliding in the direction of the rear end of the material quantity control device, blocking the axial movement of the stop element from the front end of the material quantity control device in the direction of the rear end of the material quantity control device.

[0032] In one preferred variant of the invention, the stopper member has a circumferential groove in the region of the closed end, and the adjustment member can have a hole in its rear region in which a ball is supported so as to be able to slide radially relative to the axial direction, wherein when in the fixed position the position of the hole is at the same axial level as the position of the circumferential groove, and the stopper member slides inside the adjustment member towards its front end.

[0033] In another embodiment, an additional sleeve-like fastening element can be provided which surrounds the rear end of the material quantity control device in the region of the bore and the circumferential groove and which can have a relatively large open inner diameter axially forward and a relatively small fixed inner diameter axially rearward.

[0034] Particularly preferred is an embodiment in which the locking element is axially slidably supported on the adjustment element and / or the stop element, whereby it can slide axially backwards and forwards between a locking position and an open position, whereby in the locking position the circumferential groove, the hole and the locking bore are axially level, whereas in the open position the circumferential groove, the hole and the open bore can be axially level.

[0035] In a fixed position, the ball can be pressed into or engaged with the circumferential groove of the stopper member, and the movement of the ball radially away from the central axis of the material quantity control device is restricted by a relatively small fixed inner diameter that keeps it engaged with the circumferential groove, thereby preventing axial movement of the stopper member relative to the material quantity control device.

[0036] In the open position, the ball may be deflectable radially outward, away from the central axis of the material quantity control device, due to its relatively large open inner diameter, to the extent that it no longer engages in the groove around which it circumferentially revolves, thereby allowing the stop member to slide axially backward and forward relative to the adjustment member between the open position and the locked position.

[0037] In a particularly preferred embodiment, a spring element may be provided which exerts an axial force from the fixing element on the stop element in the direction of the rear end of the material quantity control device, causing the stop element to automatically slide rearward in the open position and maintain it in this open position.

[0038] The spring member can exert an axial force on the fixing member in the direction toward the front end of the material quantity control device, which force automatically slides the fixing member forward and keeps it in a fixed position, thereby keeping the ball engaged with the groove.

[0039] The above-mentioned features make it possible to create a material quantity control device that is particularly compact in design and particularly easy to operate. Such a material quantity control device can also replace a material quantity control device that is conventionally installed on an existing spray gun, without requiring any modifications to the spray gun, and conventional material needles can also be used without adapting the length of the material needle. Therefore, no additional parts need to be manufactured, which reduces manufacturing costs.

[0040] The present invention further relates to a spray gun, particularly a handheld spray gun, for dispensing coating material, comprising a material needle and a material quantity control device for limiting the material needle stroke, having one or more of the aforementioned features. The material quantity control device is preferably attached directly to the spray gun or via at least one intervening component. The attachment means used to attach the material quantity control device to the spray gun can then be used to adjust the stroke limit position. For example, attachment can be achieved by an external thread on the material quantity control device and an internal thread on a passage in the spray gun surrounding the material needle. The position of the stop surface can be axially adjusted when the material quantity control device is screwed in or unscrewed via the thread. Such a spray gun with a material quantity control device of this type allows particularly fast and reliable function switching back and forth between the stroke limit position and the stroke open position, thereby simplifying operation of the spray gun.

[0041] In another preferred embodiment of the spray gun, the stop surface limits the maximum axial deflection of the material needle in the stroke limit position toward the rear end of the material quantity control device, allowing a reduced amount of coating material to be discharged compared to the open stroke position. Preferably, the maximum axial deflection of the material needle in the stroke limit position toward the rear end of the material quantity control device is not limited by the stop surface, allowing a maximum possible amount of coating material to be discharged. The maximum possible amount of coating material discharge is preferably understood to mean an amount in which the amount of coating material that can be discharged cannot be reduced, or can be reduced only slightly, through the limitation of the material needle stroke. In this context, slight is understood to mean a reduction of the maximum amount of material that can be discharged, preferably by less than 5%. Thus, the maximum amount of material that can be discharged in the open stroke position is primarily limited not by the material needle stroke but primarily by the design of the material nozzle.

[0042] The present invention further relates to a method for applying a coating material by means of a spray gun, in particular by means of a spray gun having one or more of the features described above, and / or by means of a material quantity control device having one or more of the features described above. First, an adjustment element is typically used to adjust the material quantity control device to a closed position in which a stop of the material quantity control device relative to the material needle of the spray gun is displaced to its maximum extent in the material discharge direction. This position forms the zero point or initial position. In this position, the material quantity control device can be completely closed. The stop surface of the material quantity control device can also completely block the axial movement of the material needle of the spray gun.

[0043] In the method according to the present invention, the material quantity control device is adjusted by an adjusting element to a stroke limiting position in which the stop surface allows the material needle to move axially to a freely definable intermediate position from which a reduced amount of material can be released. Subsequently, the quick adjustment mechanism of the material quantity control device is operated, so that the stop surface is displaced from the stroke limiting position to an open stroke position without operating the adjusting element. In this open stroke position, the material needle can be opened axially to its maximum position and an unreduced or only a small amount of material can be released. In the next step, a coating material layer is applied to the object to be coated with the maximum possible (unreduced) material release rate. After the lower material layer is applied, the quick adjustment mechanism is operated, so that the stop surface moves to the stroke limiting position from which a reduced amount of material can be released. The adjusting element is not operated at this time. In the next step, another coating material layer is applied with a reduced material release rate. Using the method described above, the lower material layer is first applied with a relatively large layer thickness, and then an upper material layer is applied, which preferably has a smaller layer thickness based on the reduced material amount. This type of method allows for reproducible application of coating material layers, preferably with two different layer thicknesses, with the thinner upper layer achieving particularly high surface quality. Furthermore, various effects are better realized with a thinner layer thickness. Unlike when multiple layers of material of the same thickness are applied, this allows for faster processing and there is no risk of the coating material drying out before the coating process is complete. Unlike the methods described above, different coating materials can be used for both layers. Further layers of different thicknesses can also be applied.

[0044] The present invention further relates to a method for applying a coating material using a spray gun, in particular using a spray gun having one or more of the features described above, and / or using a material quantity control device having one or more of the features described above. In this method, an adjustment element is used to adjust the material quantity control device to a stroke limit position in which a stop surface allows axial movement of the material needle to a freely definable intermediate position. A layer of coating material is then applied with a reduced material discharge rate. After the layer of coating material has been completely applied, a quick adjustment mechanism of the material quantity control device is operated, whereby the stop surface is displaced from the stroke limit position to an open stroke position without operating the adjustment element, allowing the material needle to be opened axially to its maximum position in the open stroke position, thereby discharging the maximum possible (unreduced) or only slightly reduced material quantity. A further layer of coating material is then applied with a non-reduced material discharge rate. The above-described method can, for example, be used to achieve special surface effects. It is also possible to produce particularly opaque coating material layers.

[0045] Next, an embodiment of the device according to the present invention will be described in detail with reference to a schematic diagram. [Brief explanation of the drawings]

[0046] [Figure 1] 1 is a perspective view showing a first embodiment of an ingredient quantity control device in a stroke limit position. FIG. [Figure 2] 2 is a partial cross-sectional view showing the first embodiment of the material quantity control device of FIG. 1 in a stroke limit position. FIG. [Figure 3] 2 is a central cross-sectional view showing the first embodiment of the material quantity control device of FIG. 1 at a stroke limit position. FIG. [Figure 4] 2 is a central cross-sectional view showing the first embodiment of the material quantity control device of FIG. 1 in a stroke open position. FIG. [Figure 5] 2 shows a spray gun having the first embodiment of the material quantity control device of FIG. 1 in an open stroke position. [Figure 6] 6 is a partial cross-sectional view of the spray gun of FIG. 5 having the embodiment of the material quantity control device of FIG. 1 in a stroke limiting position when the trigger guard is not operated. [Figure 7] 6 is a partial cross-sectional view of the spray gun of FIG. 5 having the first embodiment of the material quantity control device of FIG. 1 in a stroke limiting position with the trigger guard fully operated; [Figure 8] 6 is a partial cross-sectional view of the spray gun of FIG. 5 having the first embodiment of the material quantity control device of FIG. 1 in an open stroke position with the trigger guard fully operated; [Figure 9] FIG. 7 is a central cross-sectional view showing the spray gun of FIG. 6. [Figure 10] FIG. 10 is a central cross-sectional view showing a second embodiment of the material quantity control device in a stroke limit position. [Figure 11] FIG. 10 is a central cross-sectional view showing a second embodiment of the material quantity control device in a stroke open position. [Figure 12] FIG. 10 is a central cross-sectional view showing a third embodiment of the material quantity control device at a stroke limit position. [Figure 13] FIG. 10 is a central cross-sectional view showing a third embodiment of the material quantity control device in a stroke open position. [Figure 14] FIG. 10 is a central cross-sectional view showing a fourth embodiment of the material amount control device at a stroke limit position. [Figure 15] FIG. 10 is a central cross-sectional view showing a fourth embodiment of the material quantity control device in a stroke open position. [Figure 16] FIG. 10 is a side view showing the fourth embodiment of the material quantity control device in the stroke open position. DETAILED DESCRIPTION OF THE INVENTION

[0047] Figures 1 to 4 show a material quantity control device 1 for limiting the material needle stroke of a hand-held spray gun 3, as shown by way of example in Figure 5. The material quantity control device 1 has a front end 4 with a retaining member 5 in the form of a screw thread 14, by means of which the material quantity control device 1 can be attached to the spray gun 3 shown in Figure 5. Also shown is a rear end 6 opposite the front end 4. The material quantity control device 1 has a stop surface 7, shown in Figures 2 to 4, for limiting the material needle stroke, as well as an adjustment means 8 formed by part of the retaining member 5 in the form of a screw thread 14.

[0048] The adjusting means 8 allows the axial position of the stop surface 7 for limiting the material needle stroke to be adjusted in interaction with a corresponding counter part 9 of the spray gun 3. Furthermore, a quick adjustment mechanism 10 is shown, by means of which the stop surface 7 can be adjusted backwards and forwards in the axial direction 13 relative to the adjusting means 8 between a stroke limiting position and a stroke opening position different from the stroke limiting position, without changing the position of the adjusting means 8 and without removing the material quantity control device 1 from the spray gun 3.

[0049] In the illustrated material quantity control device 1, the stop surface 7 is arranged offset in the axial direction 13 relative to the holding means 5 towards the rear end 6 of the material quantity control device 1. In this case, in the stroke limit position, the stop surface 7 is closer to the front end 4 of the material quantity control device 1 than in the stroke open position.

[0050] 1 to 4, the adjustment means 8 extends from the front end 4 toward the rear end 6 of the material quantity control device 1. A stop surface 7 for limiting the material needle stroke can be adjusted rearward and forward in the axial direction 13 between a stroke limiting position and a stroke open position different from the stroke limiting position by a quick adjustment mechanism 10 separate from the adjustment means 8. The position of the stop surface 7 can be adjusted relative to the adjustment means 8 by the quick adjustment mechanism 10, and in the stroke limiting position, the stop surface 7 is offset in the axial direction 13 from the adjustment means 8 toward the rear end 6 of the material quantity control device 1.

[0051] As the design of the material quantity control device 1 shows, the stop surface 7 is arranged offset relative to the adjusting means 8 towards the rear end 6 of the material quantity control device 1 even when in the stroke limit position. Accordingly, the stop surface 7 is arranged closer to the rear end 6 than to the front end 4 of the material quantity control device 1, both in the stroke limit position and in the stroke open position. In an alternative embodiment, the stop surface 7 may also be arranged at the level of the adjusting means 8 in the axial direction 13 when the material quantity control device 1 is in the stroke limit position.

[0052] As can be seen from FIGS. 1 to 4, a locking means 17 is provided by means of which the adjusting means 8 can be locked in a position in the axial direction 13, the locking means 17 being configured as a counter nut 17.

[0053] 1 to 4 also show a hollow space 15 extending into the interior of the material quantity control device 1 from the front end 4 of the material quantity control device 1 towards the rear end 6 of the material quantity control device 1. As can be seen in Figures 6 to 9, the hollow space 15 is configured to accommodate a material needle 16 of the spray gun 3.

[0054] Also shown are a sleeve-shaped adjustment member 18 comprising the adjustment means 8 and a sleeve-shaped stop member 19 comprising the stop surface 7, the stop member 19 being partially arranged inside the adjustment member 18. Embodiments in which the adjustment member 18 is at least partially arranged inside the stop member 19 are also possible.

[0055] Figure 3 shows the material quantity control device in the stroke limit position, and Figure 4 shows the material quantity control device in the stroke open position. As is clear from both figures, in the stroke limit position the stop surface 7 is closer to the front end 4 of the material quantity control device 1 in the axial direction 13 than in the stroke open position, and in the stroke limit position the stop surface 7 is positioned within the half of the material quantity control device 1 that includes the rear end 6 of the material quantity control device 1.

[0056] It is also shown that the stop element 19 and the adjustment element 18 have shoulders 27, 29, respectively, which abut against each other in the open stroke position and limit the maximum rearward deflection of the stop element 19 in the open stroke position. As is clear from the illustrated construction, adjustment of the position of the stop surface 7 by the quick adjustment mechanism 10 is effected only by movement of the stop surface 7 in the axial direction 13. In the case of other embodiments of the invention, adjustment of the position of the stop surface 7 by the adjustment means 8 can also be effected by a rotational movement of the operating element 21 about the central axis of the material quantity control device 1, or by a combination of such a rotational movement with the above-described movement in the axial direction 13, as shown, for example, in Figures 10 and 11, 12 and 13 or 14 and 15.

[0057] As can be seen particularly from Figures 3 and 4, the quick adjustment mechanism 10 is configured to automatically lock in the stroke limit position and the stroke release position. To this end, the quick adjustment mechanism 10 has a locking member 22 that serves to lock the quick adjustment mechanism 10 in the stroke limit position and the stroke release position. The locking member 22 partially surrounds the adjustment member 18 and the stop member 19 in the circumferential direction. The quick adjustment mechanism 10 is configured to automatically move from the stroke limit position to the stroke release position when the locking member 22 is retracted. To this end, a spring member 37 is provided that, in cooperation with the material needle spring 47, exerts a rearward force on the stop member 19, moving it in the retracting direction, when the quick adjustment mechanism 10 is released via the locking member 22. For this reason, the locking member 22 is pulled rearward when in the stroke limit position.

[0058] As shown in FIGS. 3 and 4, the adjustment element 18 is sleeve-shaped and includes a sleeve-shaped stop element 19 that is positioned within the adjustment element 18 in a partial region and is coaxially supported on the inner surface 30 of the sleeve-shaped adjustment element 18. The adjustment element 18 is provided with an external thread 14, shown in detail in FIGS. 1 and 2, which constitutes the holding means 5 and the adjustment element 8. A locking means 17 in the form of a counter nut 17 is provided on the external thread 14. The stop element 19 is closed at its end 23, which faces the front end 4 of the material quantity control device 1. The stop surface 7 is formed on the inside 24 of the closed end 23. In the region of the open end 25 of the stop element 19 opposite the closed end 23, a shoulder 27 is provided on its outer surface 26. In the open stroke position shown in FIG. 4, this shoulder 27 abuts against a shoulder 29 on the inner surface 30 of the adjustment element 18, thereby blocking movement of the stop element 19 in the axial direction 13. The inner stopper member 19 slides to the maximum extent towards the rear end 6 of the material quantity control device 1 when in the stroke release position.

[0059] The stopper element 19 has a circumferential groove 31 in the region of the closed end 23. The adjustment element 18 has a hole 32 in its rear region, in which a ball 33 is supported so as to be able to slide radially in the axial direction 13. In the locked position shown in Figure 3, the hole 32 is at the same level as the circumferential groove 31 in the axial direction 13, and the stopper element 19 slides inside the adjustment element 18 towards the front end 4.

[0060] Also shown is a sleeve-like fastening element 22 which surrounds the rear end 6 of the material quantity control device 1 in the region of the bore 32 and the circumferential groove 31. The fastening element 22 has a relatively large open inner diameter 35 located at the front end as viewed in the axial direction 13 and a relatively small fastening inner diameter 36 located at the rear end as viewed in the axial direction 13. The fastening element 22 is supported so as to be slidable in the axial direction 13 relative to the adjustment element 18 and the stop element 19, and can thereby slide rearward and forward in the axial direction 13 between a fastening position shown in FIG. 3 and an open position shown in FIG. 4.

[0061] In the fixed position shown in Figure 3, the circumferential groove 31, the hole 32, and the fixed inner diameter 36 are at the same level when viewed in the axial direction 13, and in the open position shown in Figure 4, the circumferential groove 31, the hole 32, and the open inner diameter 35 are at the same level when viewed in the axial direction 13.

[0062] 3, the ball 33 engages the circumferential groove 31 of the stopper member 19, and the movement of the ball 33 radially away from the central axis of the material quantity control device 1 is limited by the relatively small fixed inner diameter 36, which keeps the ball 33 engaged with the circumferential groove 31. This prevents axial movement of the stopper member 19 relative to the adjustment member 18.

[0063] 4, the relatively large open inner diameter 35 allows the ball 33 to be deflected radially outward from the central axis of the material quantity control device 1 to the extent that the ball 33 no longer engages with the circumferential groove 31. In this way, the stop member 19 can be slid rearward and forward in the axial direction 13 relative to the adjustment member 18 from the stroke limiting position to the stroke open position.

[0064] A spring member 37 is provided between the stopper member 19 and the fixed member 22, and this spring member exerts a force on the stopper member 19 in the axial direction 13 toward the rear end 6 of the material quantity control device 1, which force causes the stopper member 19 to automatically slide outward from the stroke limit position to the stroke release position and remain in that position.

[0065] Conversely, the spring element 37 exerts a force on the locking element 22 in the axial direction 13 towards the front end 4 of the material quantity control device 1, which force urges the locking element 22 forward towards the locked position. However, the locking element 22 is kept in the open position by the ball 33 located in the open inner diameter 35 of the locking element 22.

[0066] To move the stop surface 7 or stop element 19 from the stroke open position shown in FIG. 4 to the stroke limiting position shown in FIG. 3, the push button 38 on the stop element 19 must be operated, causing the stop element 19 to slide toward the front end 4 until the groove 31 is again axially level with the ball 33. The ball 33 is then pressed radially inward into the groove 31. The spring element 37 then causes the unlocked locking element 22 to slide toward the front end 4, and the quick adjustment mechanism 10 is automatically locked in the stroke limiting position shown in FIG. 3, because the radial movement of the ball 33 outward is limited by the locking bore 36 of the locking element 22, which is now level with the ball 33.

[0067] To move the stop surface 7 or stop element 19 from the stroke limiting position shown in FIG. 3 to the stroke open position shown in FIG. 4, the locking element 22 slides toward the rear end 6 of the control device 1. This further compresses the spring element 37, increasing the spring force it exerts on the stop element 19 via the push button 38. As soon as the locking element 22 is displaced toward the rear end 6 of the control device 1 to the extent that the open bore 35 and the ball 33 are flush with each other, the spring force causes the ball 33 to move axially outward, thereby releasing the stop element 19 and automatically moving it rearward. As long as a forward force is not exerted on the push button 38 as described above, the spring force exerted by the spring element 37 on the push button 38 and thus on the stop element 19 keeps the stop element in the stroke open position.

[0068] Figure 5 shows an exemplary spray gun 3 for discharging coating material. The spray gun shown is a handheld spray gun 3 having a material needle 16, shown in cross section in Figure 9, and a material quantity control device 1 for limiting the material needle stroke, corresponding to Figures 1 to 4. The material quantity control device 1 is attached directly to the spray gun 3, but in alternative embodiments it can also be attached via at least one intervening component.

[0069] Figures 6 to 8 show the spray gun 3 in different material discharge states. Figure 6 shows the state with the material needle 16 not released, with no coating material being discharged. Figures 7 and 8 show the state when the trigger guard 45 is fully retracted, with the material quantity control device 1 in the stroke limit position in Figure 7 and in the stroke release position in Figure 8.

[0070] As can be seen from FIG. 7 , in the stroke limit position, the stop surface 7 limits the maximum axial deflection of the material needle 16 toward the rear end 6 of the material quantity control device 1 so that a reduced amount of coating material can be released compared to the open stroke position. This is particularly clear in relation to FIG. 8 , in which the material quantity control device 1 is in the open stroke position. It can be seen here that in the open stroke position, the material needle 16 can be displaced further rearward, thereby opening the material nozzle 54 further and thus releasing a larger amount of coating material, since the opening cross-sectional area between the material nozzle 54 and the material needle 16 is now larger. FIG. 8 also shows that in the open stroke position, the maximum deflection of the material needle 16 in the axial direction 13 toward the rear end 6 of the material quantity control device 1 is not limited by the stop surface 7, as long as the maximum possible amount of coating material can be released. Alternatively, in another embodiment, the deflection of the material needle 16 may be limited by the stop surface 7, but nevertheless the deflection of the material needle 16 is limited less in the open stroke position than in the limited stroke position.

[0071] Preferably, application of coating material by the spray gun 3 is initiated by first moving the material quantity control device 1 into a closed position (not shown) in which the material quantity control device 1 is completely closed by the adjusting member 18. In this position, the stop surface 7 of the material quantity control device 1 completely blocks movement of the material needle 16 of the spray gun 3 in the axial direction 13 (zero or initial position).

[0072] Subsequently, the material quantity control device 1 is adjusted by the adjustment member 18 to a stroke limit position, shown by way of example in FIG. 4, in which the stop surface 7 allows movement of the material needle 16 in the axial direction 13 up to an intermediate position, shown in FIG. 7, from which a reduced amount of material can be released.

[0073] Subsequently, the quick adjustment mechanism 10 of the material quantity control device 1 is operated, whereby the stop surface 7 is displaced from the stroke limit position to the stroke open position shown in FIG. 4 without operating the adjustment member 18, in which position the material needle 16 can be opened in the axial direction 13 to its maximum position as shown in FIG. 8 and an unreduced amount of material can be released.

[0074] The quick adjustment mechanism 10 is operated to move the material quantity control device 1 to the stroke open position, and then the lower coating material layer is applied to the object to be coated with an unreduced material discharge rate.

[0075] The quick adjustment mechanism 10 is then operated again, so that the stop surface 7 moves back to the stroke limiting position without operating the adjustment member 18, allowing only a reduced amount of material to be discharged.

[0076] The quick adjustment mechanism 10 is operated, whereby the material quantity control device 1 is moved to a stroke limiting position, after which the application of the upper coating material layer to the object takes place with a reduced material discharge rate.

[0077] In the case of an alternative embodiment, the coating material is applied by the spray gun 3 by first applying a lower (first) layer of coating material using the material quantity control device 1 in the stroke limit position with a reduced material discharge rate, and subsequently applying another layer of coating material using the material quantity control device 1 in the stroke open position with the maximum possible material discharge rate.

[0078] FIG. 9 shows the spray gun of FIGS. 5 to 8 in a center cross-sectional view, with the material quantity control device 1 in the stroke limit position shown in FIG. 3. The spray gun 3 has a coating agent inlet 41, to which a material supply device for supplying coating material to the spray gun 3 can be attached. In the illustrated spray gun 3, a flow cup can be attached to the coating agent inlet 41. An air valve 42 is also shown, which controls the air flow through the spray gun 3. In addition, an air supply connection 43 is provided for supplying compressed air to the spray gun 3. The spray gun 3 also has a gun grip 44, which allows the user to hold the spray gun 3. A trigger guard 45 is also provided, which controls the air valve 42 and the deflection of the material needle 16, and therefore the material discharge rate. An air quantity control device 46 is also shown, which controls the amount of compressed air reaching the air supply connection 43 to the air valve 42. A material needle spring 47 biases the material needle 16 in the material discharge direction, again moving it forward when the trigger guard 45 is released. Also shown is an air nozzle 53 that surrounds a circular material nozzle 54, also shown in the form of an annular gap, and atomizes the coating material discharged from the material nozzle 54. Both the material nozzle 54 and the air nozzle 53 are located in a nozzle head 55. The nozzle head 55 is also provided with a horn 57 that projects in the material discharge direction and carries a horn air nozzle 58. A circular jet control / wide jet control 56 allows control of how much air is discharged by the horn air nozzle 58 when the trigger guard 45 is operated.

[0079] 10 to 16 show alternative embodiments of a material quantity control device 1 according to the invention, although many other embodiments are possible which are also considered to be in accordance with the invention.

[0080] 10 and 11 show a second embodiment of the material quantity control device 1. Unlike the previously described embodiment, the stopper member 19 has a quick adjustment mechanism 10 consisting of a first quick screw thread 48 and a second quick screw thread 49. Here, the first quick screw thread 48 is longer than the second quick screw thread 49. When the quick adjustment mechanism is in the stroke limit position shown in FIG. 10, the stopper member 19 is connected to the adjustment member 18 by the shorter second quick screw thread 49. When the quick adjustment mechanism 10 is shifted to the stroke open position, the stopper member 19 is unscrewed from the adjustment member 18 by the second quick screw thread 49, and then the stopper member 19 is screwed onto the thread of the adjustment member 18 by the first quick screw thread 48. Due to the different lengths of the first quick screw thread 48 and the second quick screw thread 49, the stopper surface 7 is farther away from the front end 4 of the material quantity control device 1 in the stroke open position than when it is in the stroke limit position.

[0081] 12 and 13 show yet another embodiment of the material quantity control device 1, which differs from the previously described embodiments in that the stop member 19 and the adjusting member 18 are connected via a threaded knob 50, which carries an external thread 60 at its front end, so that the threaded knob 50 is connected to the adjusting member 18 and can be displaced forward or backward relative to the adjusting member 18 via the thread 60 when the threaded knob 50 is turned about its own axis. The threaded knob 50 has an inner bore 61 at its front end, in which the stop member 19 is freely rotatable but positively supported in the axial direction 13, so that when the threaded knob 50 is turned circumferentially to the right or left, the stop member 19 moves forward or backward together with the threaded knob 50 relative to the adjusting member 18. In this way, the stop surface 7 of the stop member 19 can be moved relative to the adjusting member 18 from a stroke limiting position (FIG. 12) to a stroke opening position (FIG. 13).

[0082] 14 to 16 show yet another embodiment of the material quantity control device 1. In this embodiment, as can be seen in FIG. 16, a portion of the stop member 19 is substantially triangular in cross section, with the side of the triangular portion forming the return offset 52. At the front end of the return offset 52, the triangular cross section transitions into a circular cross section, with its outer diameter located at the vertex of the triangular cross section. The transition between the triangular cross section and the circular cross section forms a return offset shoulder 59 on each side of the triangle. Furthermore, an intervening fixing element 22 having a snap hook 51 is provided. This is configured to engage with the return offset shoulder 59 in the stroke limit position shown in FIG. 14 when the angular positions of the return offset shoulder 59 and the snap hook 51 coincide with each other relative to the axis of the material quantity control device 1. In this way, the stop member 19 is maintained in the stroke limit position even when the material needle 16 or, if applicable, the material needle spring 47 presses directly backward in the axial direction 13 against the stop member 19.

[0083] To move the stop member 19 to the stroke release position (FIG. 15), the stop member 19 is rotated about its own axis until the snap hooks 51 are positioned on the circular outer diameter of the stop member 19 and displaced outwardly enough to disengage from the return offset shoulder 59. The force exerted directly on the stop member 19 by the material needle 16 or material needle spring 47 then displaces it to the stroke release position.

[0084] When a force is applied to the rear end 6 of the material quantity control device 1, the stop member 19 is again displaced forward and can be fixed in the stroke limit position by rotation about its own axis. As with the other embodiments, the material quantity control device 1 can have position markings 40 that indicate the angular position of the material quantity control device 1 relative to the spray gun.

[0085] With reference to the drawings and the above-described embodiments, preferred embodiments of the present invention are described by way of example only. Other design forms, materials, or connection methods are conceivable and will be apparent to those skilled in the art from the teachings of the embodiments and the prior art. Individual features of the embodiments can be combined with one another, even if not explicitly stated. This also applies to the embodiments themselves. If a combination is not possible or meaningful, the skilled artisan will unambiguously recognize this. All embodiments can be applied to various types of spray guns, even if not explicitly stated. [Explanation of symbols]

[0086] 1.Material quantity control device 3. Spray gun 4. Front end (of material quantity control device) 5. Holding means (of material quantity control device) 6. Rear end of the material quantity control device 7. Stopper surface 8. Adjustment means (for material quantity control devices) 9. Spray gun compatible parts 10. Quick adjustment mechanism 13. Axial direction 14. Thread 15. Hollow Space 16. Material Needle 17.Latching means 18. Adjustment parts 19.Stopper member 21. Operating member (for rotational movement) 22. Fixing member 23. Closed end of stopper member 24. Inside the closed end of the stopper member 25. Open end of stopper member 26. Outer surface of stopper member 27. Shoulder of stopper member 29.Adjustment member shoulder 30.Inner surface of adjustment member 31. Circling Groove 32. Hole 33. Ball 35.Open inner diameter 36.Fixed inner diameter 37. Spring parts 38. Push Button 39. Coupling screw 40. Position marking 41. Coating agent inlet 42. Air valve 43.Air supply connection 44. Ganglion Grip 45. Trigger guard 46.Air volume control device 47.Material needle spring 48. First quick screw thread 49. 2nd quick thread 50. Threaded knob 51. Snap Hook 52. Return offset 53.Air nozzle 54.Material nozzle 55.Nozzle head 56.Circular jet control unit / wide jet control unit 57. Horn 58. Horn air nozzle 59. Return offset shoulder 60. Male thread of threaded knob 61. Inner hole of threaded knob

Claims

1. 1. A material quantity control device for limiting a material needle stroke of a material needle of a handheld spray gun, the material quantity control device comprising: a front end having a mounting member for removably mounting the material quantity control device to the spray gun; a rear end opposite the front end; a stop surface that limits the material needle stroke; an adjustment member operatively associated with the mounting member, through which the adjustment member interacts with a corresponding counterpart on the spray gun, such that rotation of the adjustment member moves the mounting member to adjust the axial position of the stop face relative to the spray gun to vary the material needle stroke; and a quick adjustment member by which the stop surface can be selectively changed between a stroke limiting position that allows movement of the material needle a first stroke length and a stroke open position that allows movement of the material needle a second stroke length without rotating the adjustment member, without moving the mounting member, and without removing the material quantity control device from the spray gun; the second stroke length is longer than the first stroke length; at least in the stroke limit position, the stop surface is arranged at the level of the mounting member in the axial direction or is offset relative to the mounting member in the axial direction towards the rear end of the material quantity control device. Material quantity control device.

2. The material quantity control device of claim 1 , wherein the mounting member is configured in the form of a screw thread.

3. 3. A material quantity control device as claimed in claim 1, characterized in that the stop surface is arranged at the level of the adjustment member or offset relative to the adjustment member in the direction of the rear end of the material quantity control device at least when in the stroke limit position.

4. 4. The material quantity control device according to claim 3, wherein said stopper surface is located closer to said rear end than to said front end of said material quantity control device at least when said stopper surface is in the stroke limit position.

5. 3. The material quantity control device according to claim 1, wherein the material quantity control device has a hollow space configured to accommodate a material needle of the spray gun, the hollow space extending from the front end of the material quantity control device toward the rear end of the material quantity control device.

6. 3. The material quantity control device according to claim 1, wherein the stopper surface is located closer to the front end of the material quantity control device in the axial direction when the stopper surface is in the stroke limit position than when the stopper surface is in the stroke open position.

7. 7. The material quantity control device according to claim 6, wherein said stop surface is positioned within a half of said material quantity control device, including said rear end portion of said material quantity control device, when said stop surface is in the stroke limit position.

8. 3. A material quantity control device according to claim 1, further comprising a locking means for locking the material quantity control device axially relative to the spray gun in a position adjusted by the adjusting member.

9. 9. The material quantity control device according to claim 8, wherein the locking means is configured as a counter nut.

10. 3. The material quantity control device according to claim 1, further comprising an adjustment member including the adjustment member, and a stopper member including the stopper surface, wherein the stopper member and the adjustment member are displaceable relative to each other in the axial direction.

11. 11. The material quantity control device according to claim 10, wherein the adjusting member has a sleeve shape, and the stopper member has a sleeve shape.

12. 11. The material quantity control device according to claim 10, wherein said stopper member and said adjustment member each have a shoulder portion which abuts against each other when in the stroke open position.

13. 3. The material quantity control device according to claim 1, wherein the position of the stopper surface is adjusted by the quick adjustment member through axial movement of the stopper surface, and / or the position of the stopper surface is adjusted by the adjustment member through screw movement around the central axis of the material quantity control device.

14. 3. A material quantity control device according to claim 1, wherein the quick adjustment member is adapted to be automatically locked in the stroke limit position and / or the stroke open position.

15. 3. A material quantity control device according to claim 1, wherein the quick adjustment member comprises a fixing element which serves to lock the quick adjustment member in the stroke limiting position and / or the stroke open position.

16. 16. The material quantity control device according to claim 15, characterized in that an adjustment member including the adjustment member and a stopper member including the stopper surface are provided, and the fixing member at least partially surrounds the adjustment member and / or the stopper member in the circumferential direction.

17. 3. The material quantity control device according to claim 1, wherein the quick adjustment member is automatically moved from the stroke limiting position to the stroke releasing position by the movement of the fixing member.

18. 3. The material quantity control device according to claim 1, further comprising a sleeve-shaped adjusting member and a sleeve-shaped stopper member arranged in a partial region inside the adjusting member and coaxially supported on the inner surface of the sleeve-shaped adjusting member, the adjusting member having an external thread that forms the mounting member and the adjusting member, on which a locking means in the form of a counter nut is provided, the stopper member being closed at its end opposite to the front end of the material quantity control device, the stop surface being formed on the inside of the closed end, and the outer surface of the stopper member being provided with a shoulder in the region of its open end opposite to the closed end, which shoulder abuts against a shoulder on the inner surface of the adjusting member when the inner stopper member is in a stroke open position in which it has slid maximally toward the rear end of the material quantity control device, thereby blocking axial movement of the stopper member from the front end of the material quantity control device to the rear end of the material quantity control device.

19. An adjusting member including the adjusting member is provided, and a stopper member including the stopper surface is provided, the stopper member having a circumferential groove, the adjusting member having a hole in which a ball is supported so as to be slidable in the radial direction relative to the axial direction, and an additional sleeve-like fixing member is provided which surrounds the rear end region of the material quantity control device in the region of the hole and the circumferential groove and has a relatively large open inner diameter located forward as viewed in the axial direction and a relatively small fixed inner diameter located rearward as viewed in the axial direction, the fixing member being slidable rearward and forward in the axial direction relative to the adjusting member and the stopper member between a fixed position and an open position, and when the fixing member is arranged in the fixed position, the circumferential groove, the hole, and the fixed inner diameter are at the same level in the axial direction, and the stopper member is attached to the adjusting member.

3. A material quantity control device according to claim 1, wherein the stopper member is arranged in a stroke limiting position relative to the adjustment member, whereby the ball is forced radially inward by the fixed inner diameter of the fixing member into the groove of the stopper member, thereby locking the stopper member in the stroke limiting position relative to the adjustment member, and when the fixing member is arranged in an open position, the hole is at the same axial level as the ball supported therein and the open inner diameter of the fixing member, whereby the ball can be displaced radially outward from the groove of the stopper member into the open inner diameter, whereby the stopper member can slide backward and forward in the axial direction relative to the adjustment member between the stroke limiting position and the stroke open position.

20. 17. The material quantity control device according to claim 16, wherein a spring member is provided, through which the stopper member and the fixing member are axially supported to each other.

21. 1. A spray gun for discharging a coating material, comprising a material needle and a material quantity control device for limiting the material needle stroke as claimed in claim 1 or 2, wherein the material quantity control device is attached directly to the spray gun or via at least one intervening component.

22. 22. The material quantity control device of claim 21, wherein the spray gun is a hand-held spray gun.

23. 22. The spray gun of claim 21, wherein the stop surface, when in the stroke limit position, limits the maximum axial deflection of the material needle toward the rear end of the material quantity control device so as to allow the release of a reduced amount of coating material compared to the open stroke position.

24. 24. A spray gun as claimed in claim 23, characterized in that the maximum axial deflection of the material needle in the axial direction towards the rear end of the material quantity control device is not limited by the stop surface in the stroke open position, so that the maximum possible amount of coating material can be released.

25. 22. A method of applying a coating material with a spray gun as claimed in claim 21, comprising the steps of: a) the material quantity control device is adjusted by an adjustment member including the adjustment member to a stroke limit position where the stop surface allows the material needle to move axially to an intermediate position where a reduced amount of material can be released, b) the quick adjustment member of the material quantity control device is operated, whereby the stop surface is displaced from a stroke limiting position without operating the adjustment member to a stroke opening position in which the material needle can be opened axially to its maximum position and the maximum possible material quantity can be released; c) the coating material layer is applied with the greatest possible material release; d) the quick adjustment member is operated, whereby the stop surface moves back to a stroke limiting position where a reduced amount of material can be released without operating the adjustment member; e) the layer of coating material is applied with reduced material release.

26. 22. A method of applying a coating material with a spray gun as claimed in claim 21, comprising the steps of: a) the material quantity control device is adjusted by an adjustment member including the adjustment member to a stroke limit position where the stop surface allows the material needle to move axially to an intermediate position where a reduced amount of material can be released, b) the coating material layer is applied with reduced material release; c) the quick adjustment member of the material quantity control device is operated, whereby the stop surface is displaced from a stroke limiting position without operating the adjustment member to a stroke opening position in which the material needle can be opened axially to its maximum position and the maximum possible material quantity can be released; d) the layer of coating material is applied with the greatest possible material release.

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