EP4188611A1

EP4188611A1 - Fluid reservoir for a spray gun with a ventilation device

Info

Publication number: EP4188611A1
Application number: EP21752024.6A
Authority: EP
Inventors: Peter Dettlaff
Original assignee: SATA GmbH and Co KG
Current assignee: SATA GmbH and Co KG
Priority date: 2020-07-31
Filing date: 2021-07-29
Publication date: 2023-06-07
Also published as: CN116056798A; WO2022023465A1; US20230271202A1; DE102020120229A1; CA3188155A1

Abstract

The invention relates to a fluid reservoir (11) for a spray gun (1), which fluid reservoir has a material outlet which is configured for the direct and/or indirect connection to a spray gun (1), wherein the fluid reservoir (11) comprises a material container (13) which is closed at least at one end face by a disk-shaped closing wall (71), wherein a ventilation device (16) is arranged on the outside of the closing wall (71). Advantageously, the closing wall (71) is provided with a concavity which uniformly extends over the closing wall (71).

Description

Gravity cup for a spray gun with an aeration device

The invention relates to a flow cup for a spray gun, which has a material outlet designed for direct and/or indirect connection to a spray gun, the flow cup having a material container which is closed off at least on one end by a disc-shaped end wall, with the Outside of the end wall a ventilation device is arranged, through which air can flow into the flow cup to allow pressure equalization when material flows out of the flow cup via the material outlet.

Such a flow cup is known, for example, from DE 10 2004 007 733 A1. The flow cup described there comprises a cup-shaped container and a lid that can be screwed onto it via a thread. On its upper side, the cover has an outlet socket with an outlet opening, which is designed for direct or indirect (by means of an adapter) connection to a spray gun. In order to ensure pressure equalization when material flows out of the flow cup via the outlet nozzle, a ventilation valve is provided on the outside of the bottom of the cup-shaped container, which forms a disk-shaped end wall of the container.

Even if gravity cups can be reused relatively often, depending on the design, they are consumables that are consumed in large numbers in a normal paint shop. Your procurement costs therefore play an economic role and are determined to a significant extent by the transport and storage costs of the gravity cup, which in turn are influenced by the space required by the individual gravity cup for storage and transport.

From US 2019/126300 A a flow cup is known, the ventilation valve of which is offset inwards and accommodated in a central depression in the bottom of the material container. The space requirement of the material container is reduced by this measure. The disadvantage, however, is that the ventilation valve arranged in the trough is difficult to access from the outside. The invention has therefore set itself the goal of reducing the space requirement of the generic flow cup without any loss of handling or functionality.

The object is achieved by a flow cup with the features of claim 1.

According to the invention, the end wall of the material container, on the outside of which the ventilation device is arranged, is provided with an indentation which extends evenly over the end wall. In particular, there is a concave curvature towards the interior of the material container.

Thanks to the uniform curvature, the ventilation device protrudes axially less than the edge area of the closing wall, which reduces the space required by the material container. At the same time, the ventilation device is still freely accessible from the outside. The defined inward curvature of the end wall also ensures that a disadvantageous convex curvature of the end wall, e.g. caused by the injection molding process, is reliably ruled out.

It goes without saying that the indentation is present in the basic state of the material container and not only when a force is applied to the end wall, e.g. B. by an internal pressure or the like.

The disc-shaped closing base is preferably produced from plastic, if necessary together with other components of the flow cup, in a plastic injection molding process. The indentation is created by a correspondingly curved cavity in the injection molding tool.

The curved end wall can also be advantageous for the injection molding process. A favorable choice of the injection point can reduce the curvature when filling the Tool cavity with liquid plastic under high pressure cause or support a centering of the injection mold parts to each other.

In practice, an embodiment of the invention has proven itself in which the point of the concave end wall, which protrudes furthest inward due to the indentation, has an offset or a depth of 1% to 4%, preferably from 1.5% to 3% of the diameter of the end wall. The relatively slight indentation results in the desired effect of a reduced space requirement, with the stability and manufacturability of the flow cup not being adversely affected at the same time.

In preferred exemplary embodiments, the concave end wall is circular with a defined diameter. In alternative embodiments, the shape of the end wall can also deviate from a circular shape and z. B. be elliptical or rectangular. In this case, the maximum width is to be regarded as the diameter for determining the preferred form of the indentation described above.

In a particularly preferred embodiment, the ventilation means comprises an off-centre ventilation opening through the domed end wall, which is offset from the center of the end wall by preferably greater than 5% and less than 10% of the diameter of the end wall. In this way, the ventilation device is arranged at least almost centrally on the end wall, but due to the off-center arrangement of the ventilation opening, the injection point can be selected as exactly as possible in the middle when producing the end wall in an injection molding process.

A preferred exemplary embodiment is characterized by good accessibility of the corner region between the end base and a connected peripheral wall of the flow cup, in that the curved end wall adjoins the peripheral wall of the flow cup at an angle of greater than 90°. However, the angle is preferably less than 95°.

The concave end wall and the peripheral wall enclose an angle of greater than 90° and preferably less than 95°.

For the same reason, the curved end wall preferably merges into the peripheral wall with a relatively large radius of curvature.

The peripheral wall of the gravity cup is preferably widened conically, starting from the end face which is closed by the concave end wall. Thanks to the conical design, the component of the flow cup that is closed with the end wall can be stacked with other components of the same type, which enormously reduces the space required for the individual component during transport.

Particularly preferred is a variant in which the conicity also results in the concave end wall adjoining the peripheral wall at an angle of greater than 90° or the concave end wall and the peripheral wall enclose an angle of greater than 90° and preferably less than 95° .

In the case of a preferred variant, a peripheral edge is provided which projects outwards from the concave end wall. The peripheral edge can serve to hold back any material that may escape via the ventilation device. Depending on the design of the gravity cup, the peripheral edge can also serve as a standing edge for the component of the gravity cup that is provided with the concave end wall.

Mechanically actuated ventilation devices have proven themselves when used in the painting environment due to their functional reliability and robustness. A variant of the invention is therefore preferred in which the ventilation device comprises a closure element which can be moved between an open position, in which air can flow into the flow cup, and a closed position which no air can flow through the aeration device into the flow cup. The closure element is preferably moved between the open position and the closed position along the longitudinal axis of the gravity cup or transversely to the curved end wall.

The movable closure element of the ventilation device preferably stands back in relation to the peripheral edge in the closed position and/or protrudes in relation to the peripheral edge in the open position.

In a particularly preferred embodiment, the concave end wall is detachably connected to the material container.

The arched end wall is preferably part of a lid of the flow cup. In addition, the material outlet, in particular in the form of an outlet connector, can be provided on the side of the material container opposite the cover. In this case, the flow cup according to the invention is designed as a standard flow cup.

Alternatively, the flow cup according to the invention can be designed as an upsidedown flow cup. The concave end wall forms the bottom of a cup-shaped material container. The material outlet, in particular in the form of an outlet nozzle, is formed on a removable cover of the flow cup. The arched end wall is preferably produced in one piece together with the tubular, in particular slightly conical, container wall in an injection molding process from plastic.

The material container is designed in particular in such a way that several material containers can be stacked one inside the other, preferably with an overhang of less than 20%, preferably less than 15%, more preferably less than 10% of the total height of the individual material container.

In the material container with a uniformly arched bottom, unhindered and complete mixing of materials, for example a paint made up of several components.

The inside of the concave end wall preferably forms a flat or smooth surface, in particular when the ventilation device is closed. As already mentioned, the cover and the material container are preferably made of plastic in an injection molding process. It is particularly advantageous if the cover and/or the material container are produced as a one-piece plastic injection molded part. It goes without saying that the cover and the material container are also to be regarded as a component produced in one piece if individual smaller components are produced separately. For example, it has proven useful in practice not to manufacture sieve elements, (movable) valve bodies, caps, etc. in one piece with the cover or the material container. However, this is entirely conceivable and technically feasible. The flow cup according to the invention is preferably an extremely thin-walled product. So the wall thickness of the material container z. B. in the range of 0.55 mm to 0.65 mm, preferably at 0.60 mm, and / or the wall thickness of the lid z. B. in the range of 0.75 mm to 0.85 mm, preferably at 0.80 mm.

The invention is explained below using exemplary embodiments. The figures show:

Fig. 1 is a sectional view of a spray gun with a

Gravity cup according to a first embodiment of the invention,

Fig. 2 is a detail sectional view of the flow cup according to Figs. 1 and 9 in the area of the connection between the lid and the material container of the flow cup,

Figs. 3 to 5 partial sectional representations of the flow cup according to FIGS. 1 and 9 in the area of the ventilation system in three different states,

Figs. 6 and 7 a perspective and a side view of the closure element of the ventilation device of the gravity cup according to FIGS. 1 and 9,

8 shows a perspective view of an alternative embodiment of the closure element of the ventilation device of the flow cup according to FIGS. 1 and 9,

9 shows a sectional view of a flow cup according to a second embodiment of the invention,

Figs. 10 and 11 a perspective and a sectional view of the lid of the flow cup according to FIG. 9,

Fig. 12 is a perspective view of the material container of the

Flow cup according to FIG. 9 and

Figs. 13 and 14 are a perspective view and a plan view of a alternative embodiment of the closure element of the ventilation device of the flow cup according to Figs. 1 and 9

FIG. 1 shows a hand-held spray gun 1 for the compressed air-assisted atomization and application of a free-flowing coating material. The spray gun 1 can be designed, for example, as a so-called high-pressure, compliant or HVLP spray gun 1 . The spray gun 1 has a cup connection 2 and a nozzle head 3 at which the coating material supplied to the spray gun 1 via the cup connection 2 is atomized and emerges in the form of a spray jet.

Furthermore, the spray gun 1 comprises a handle 4, a trigger guard 5 for actuating a material needle 10 arranged inside the spray gun 1, an adjustment mechanism 6 for the stroke of the material needle (material quantity regulation), an air pressure adjustment device 7 (micrometer), a round/broad jet adjustment device 8 and a compressed air connection 9. B. an atomization and transport air on the one hand and a horn air for a wide beam formation on the other hand.

A flow cup 11 is connected to the cup connection 2 of the spray gun 1 by means of a material outlet designed as an outlet socket 12 . The flow cup 11 has a material container 13 on the bottom 14 of which the outlet connector 12 is formed. Furthermore, the flow cup 11 comprises a screw cap 15 which closes the material container 13 and is provided with a ventilation device 16 . The ventilation device 16 enables pressure equalization when coating material flows out of the flow cup 11 via the outlet connection 12. Inside the material container 13 there is a sieve element 17 through which the coating material must pass before it can leave the material container 13 via the outlet connection 12.

The outlet connector 12 is equipped with connection means in the manner of a bayonet Closure equipped, which comprise a clamping wedge element 18 projecting radially from the outlet nozzle 12 . The clamping wedge element 18 engages in a corresponding receiving groove 19 on the spray gun 1 . The outlet port 12 seals axially z. B. by means of its end face 20 on the cup connection 2 and/or radially with the aid of two circumferential radial sealing lips 21 (hardly visible in FIG. 1 due to the proportions, see also FIG. 10).

The gravity cup 11 according to FIG. 1 is designed as a standard gravity cup.

The screw connection 22 between the screw cap 15 and the material container 13 is described in detail below with reference to FIG. The design of the screw connection 22 can be regarded as an independent subject matter of the invention, independently of the design of the concave end wall. FIG. 2 shows an enlarged section of the flow cup 11 according to FIGS. 1 and 9 in the area of the connection point between screw cap 15 and material container 13.

The edge area of the material container 13 is provided with a roll-up 23 which is reinforced by means of a plurality of radial transverse ribs 28 . The transverse ribs 28 end almost conclusively with the outer edge of the roll-up 23. The roll-up 23 has an outer leg 24, a central connecting web

25 and an inner leg 26 on. The inner leg 26 transitions into a peripheral wall 27 of the material container 13 . 2 shows a section through a radial transverse rib 28 which is integral with the outer and inner leg 24,

26 and the middle connecting web 25 is formed. The dotted lines in FIG.

Four threaded elements in the form of thread ridges 30 are provided on the outside of the outer leg 24 of the roll-up 23 . The thread ridges 30 are identical in construction to the thread ridges 30 shown in FIG. 12. FIG. 12 shows the material container 13 of a second exemplary embodiment of a flow cup 11, which will be described in more detail later, but whose screw connection 22 is identical in construction io is carried out and insofar is also shown in FIG.

The edge area of the screw cap 15 has a receiving groove 31 which is also formed by an outer leg 32 , a central connecting web 33 and an inner leg 34 . In the closed state of the flow cup 11, the receiving groove 31 encompasses the roll-up 23 in the edge area of the material container 13.

Inside the receiving groove 31, more precisely on the inside of the outer leg 32, four thread ridges 36 are formed, together with the thread ridges

30 form the multi-threaded screw connection 22 on the material container 13 . All four thread webs 36 begin approximately at the lower edge of the outer leg 32 and open into the middle connecting web 33, which is the bottom of the receiving groove

31 forms. The thread webs 36 therefore partially overlap in the circumferential direction, but are axially offset from one another in the overlapping area. This can also be seen from FIG. 2, which shows two thread webs 36 lying axially one above the other and overlapping in the circumferential direction. This can be seen even more clearly in FIG. 11, which shows a sectional illustration through the screw cap 15 of the second exemplary embodiment, in which the screw connection 22, as already mentioned, is of identical design.

The fluid-tight seal between the screw cap 15 and the material container 13 is provided by a circumferentially sealing, radial and axial contact inside the receiving groove 31. Specifically, the radial seal is provided between the outside of the inner leg 34 of the receiving groove 31 and the inside of the inner leg 26 of the roll-up 23 of the material container 13. The axial seal occurs between the top of the middle connecting web 33 of the roll-up 23 and the bottom of the middle connecting web 25 of the receiving groove 31.

In an embodiment that is not shown, analogously to the embodiment according to FIG the additional axial seal, no seal or a radial seal (and support) between the inside of the outer leg 32 of the receiving groove 31 and the outside of the outer leg 24 of the roll-up portion 23 of the material container 13 . The second radial seal and, if necessary, support can preferably take place near the corner area at the transition from the outer leg 24 to the central connecting web 25 of the roll-up 23 .

As an example, three circumferential sealing ribs 41 are shown in FIG. 2, which are formed on the outside of the inner leg 34 of the receiving groove 31 and lead to a further strengthening of the sealing effect. In addition, the sealing effect is improved in that the inner diameter of the material container 13 in the upper edge area is selected in such a way that the material container 13 is spread open when the screw cap 15 is installed, at least in the area of the roll-up 23, and this results in a particularly strong and sustained radial compression between the screw cap 15 and material container 13 results.

It goes without saying that, as an alternative or in addition, further sealing ribs, lips, beads can also be formed at other points in order to increase the sealing effect. Alternatively, for example, only an axial or only a radial seal between the screw cap 15 and the material container 13 can take place.

A central area 42 of the screw cap 15 is designed as a continuation of the inner leg 34 of the receiving groove 31 . In Fig. 2 only an outer portion of the central portion 42 of the screw cap 15 is shown. In particular, the inner leg 34 is followed by a first ring section 43 of the central area 42 which extends at least almost perpendicularly to the receiving groove 31 . The ring section 43 is followed by a second ring section 44 of the central region 42 which runs at least almost parallel to the inner leg 34 in such a way that a compensating ring groove 45 is formed which is open in the opposite direction to the receiving groove 31 . By means of the compensating ring groove 45 z. B. manufacturing tolerances of the components are compensated, in particular to ensure the functionality, strength and tightness of the screw connection 22. In addition, the dimensioning of the compensating ring groove 45 is a desired support or rigidity of the inner leg 34 can be defined.

1, the central area 42 of the screw cap 15 is provided with a ventilation device 16 in the case of the embodiment according to FIG. The structure of the ventilation device 16 is explained below with reference to FIGS. 3 to 5, which show the ventilation device 16 in three different states, and Figs. 6 and 7 explained in more detail. The design of the ventilation device 16 can be regarded as an independent subject matter of the invention, independently of the design of the concave end wall.

The ventilation device 16 is designed as a plug-in valve. It comprises a movable cap-shaped closure element 51 with a cap plate 52 from which a hollow collar 53 and a central hollow protuberance protrude. The hollow protuberance forms a hollow sealing plug 55 which protrudes axially relative to the hollow collar 53 by a distance which at least almost corresponds to the wall thickness of the flow cup 11 in the area of the aeration device 16 (see also FIG. 6).

The sealing plug 55 is provided with a circumferential shoulder 56 from which in turn an almost cylindrical plug tip 57 protrudes. The hollow collar 53 has first and second latching lugs 58, 59 which are axially offset relative to one another on the outer circumference. The first and second latching lugs 58, 59 are spaced apart from one another in the circumferential direction, as a result of which air channels 60 are formed.

The structure of the closure element 51 is shown in particular in FIGS. 6 and 7, which show the closure element 51 in a side view and a perspective top view. The design of the closure element 51 can be regarded as an independent subject matter of the invention, independently of the design of the arched end wall. On the outside of the flow cup 11 , the ventilation device 16 has a ventilation opening 61 and three hollow collars arranged concentrically to the ventilation opening 61 . The outer hollow collar 62 is provided on its open end face with an insertion chamfer 63 for the closure element 51 and a subsequent circumferential latching edge 64 . The middle hollow collar 65 forms a separate centering, retaining and guiding device. It is provided with a centering chamfer 66 on its outer circumference on its open end face. The inner hollow collar 67 forms the edge of the ventilation opening 61 and is provided with a centering chamfer 68 on its open end face.

The outer hollow collar 62 protrudes from the outside of the flow cup 11 by approximately three to four times the amount compared to the other two hollow collars 65, 67. The central hollow collar 65 protrudes from the inner hollow collar 67 approximately by the amount by which the closure plug 55 protrudes from the hollow collar 53 on the closure element 51 .

To assemble the ventilation device 16 , the closure element 51 is inserted into the outer hollow collar 62 , which is facilitated by the insertion chamfer 63 . The closure element 51 can be separated from the flow cup 11 or z. B. via a tear-off tab, web, film hinge, etc. to the screw cap 15 or the material container 13 of the flow cup 11 and are made available to the user. The ventilation device 16 can also be pre-assembled in the factory and delivered to the user in working order.

In FIG. 3 the ventilation device 16 is shown in the maximum open position of the closure element 51 . The first latching lugs 58 on the hollow collar 53, which is arranged on the closure element 51, engage behind the circumferential latching edge 64 on the outer hollow collar 62 on the outside of the flow cup 11. The interaction of the first latching lugs 58 and the circumferential latching edge 64 means that the closure element 51 cannot be lost attached to the flow cup 11. The frictional connection between the hollow collars 53, 62 prevents the closure element 51 from moving downwards from the maximum open position in FIG. 3 without an external force device or solely by the effect of gravity. Specifically, the first latching lugs 58 are designed in such a way that they are pressed radially with the inner peripheral surface of the outer hollow collar 62 . But it is also conceivable that further locking means such. B. in the form of a second circumferential locking edge below the front locking edge 64, which counteract an undesirable slipping and tilting of the closure element 51.

In the maximum open position shown, there is a certain amount of play between the peripheral latching edge 64 on the outer hollow collar 62 and the outer peripheral surface of the hollow collar 53 , through which play air can enter the flow cup 11 . The flow path via which air from the outside gets into the interior of the gravity cup 11 in order to ensure pressure equalization when coating material leaves the material container 13 via the outlet nozzle 12 is sketched in FIG. 3 as a dashed arrow 69 . After the inflowing air has passed the play or the gap formed thereby at the latching edge 64, it flows between the first latching lugs 58 through the air channels 60 and finally through the ventilation opening 61 into the interior of the flow cup 11.

The constriction in the contact area of the outer hollow collar 62 and the hollow collar 53 has the advantage that even when the ventilation device 16 is in the open state, coating material is prevented from escaping if it sloshes or sprays out of the flow cup 11 through the ventilation opening 61 during the spraying process .

In addition, it is also conceivable that the circumferential locking edge 64 is designed with many smaller openings, i.e. segmented, so that the inflowing air can flow through these openings and not (only) through the gap created by the play between locking edge 64 and the outer peripheral surface of the Hollow collar 53 is formed, can flow. In this case, play between the locking edge 64 and the outer peripheral surface of the hollow collar 53 can also be completely dispensed with and the two components fit together at the point. The closure element 51 and in particular the cap plate 52 protrude significantly beyond an outer peripheral edge 70 of the flow cup 11 . An exemplary configuration of the peripheral edge 70 can be seen in FIG. 1 .

Thanks to the overhang, a user can clearly see when the ventilation device 16 is in the open state. In addition, when the gravity cup 11 is placed down on the peripheral edge 70 with the side equipped with the ventilation device 16 and a user has failed to close the ventilation device 16 beforehand, the closure element 51 is Gravity cup 11 is to be parked, automatically pushed towards the closed position. This prevents large quantities of the coating material from accidentally escaping. If he places the (still) empty flow cup 11 with the ventilation device 16 open on the peripheral edge 70, the flow cup 11 tilts back and forth due to the protruding cap plate 52, which advantageously draws the user's attention to the ventilation device 16 that is still open before he fills in the coating material .

In order to close the ventilation device 16 in the usual way, a user presses on the cap plate 52, as a result of which the closure element 51 moves downwards in a straight line until it initially assumes the intermediate position according to FIG. In the course of this first section of the closing movement, the closure element 51 is guided by the interaction of the two hollow collars 53, 62. In particular, the closure element 51 is guided by the first latching lugs 58 sliding along the inner peripheral surface of the outer hollow collar 62 .

In the intermediate position according to FIG. 4, the second latching lugs 59 meet the latching edge 64 on the outer hollow collar 62. At least almost simultaneously, the end face of the hollow collar 53 meets the centering chamfer 66 on the middle hollow collar 65 and the plug tip 57 meets the centering chamfer 68 the inner hollow collar 67. The meeting at the three different points results in a precise and functionally reliable centering of the closure element 51 and in particular the sealing plug 55 before the sealing plug 55 penetrates into the ventilation opening 61 during the further closing movement.

The last part of the closing movement follows, in which the closure element 51 is transferred from the intermediate position shown in FIG. 4 to the closed position shown in FIG. In this movement section, the closure element 51 is additionally guided by the interaction of the hollow collar 53 and the central hollow collar 65 . In particular, the inner peripheral surface of the hollow collar 53 slides along the outer peripheral surface of the central hollow collar 65. In this very delicate movement section, the closure element 51 is guided in a very robust and stable manner.

In FIG. 5 the closure element 51 assumes the closed end position. The sealing plug 55 closes the ventilation opening 61. It rests against the inner peripheral surface of the opening 61 in a sealing manner. In this state, neither air can flow into the flow cup 11 via the ventilation device 16, nor can coating material escape from the flow cup 11 via the ventilation device 16.

The fact that the end face of the hollow collar 53 is arranged or enclosed in an annular space between the outer hollow collar 62 and the central hollow collar 65 also results in a type of labyrinth restraint device. As a result, in particular, coating material is held back that has entered the space between the inner and central hollow collars 67, 65 before the ventilation device 16 is closed, thus preventing it from getting out into the environment.

In particular, the inner peripheral surface of the hollow collar 53 can also lie tightly against the outer peripheral surface of the central hollow collar 65 so that an escape of coating material is counteracted even more effectively. It can be seen from FIG. 5 that the shoulder 56 on the closure plug 55 rests on the end face of the inner hollow collar 67 in the closed end position, which defines the axial position of the closure element 51 in the closed end position. The defined axial stop ensures that the closure plug 55 does not penetrate too far into the interior of the flow cup 11 and does not protrude inward relative to the end wall 71 .

Furthermore, it can be seen from FIG. 5 that the cap plate 52 now stands back from the peripheral edge 70 . The closure element 51 is held in a functionally reliable manner in the closed end position by the interaction of the second latching lugs 59 on the hollow collar 53 and the circumferential latching edge 64 on the outer hollow collar 62 .

In order to open the ventilation device 16 again, a user can grip the closure element 51 on the cap disk 52 and pull it upwards back into the maximum open position according to FIG. 3 .

8 shows an alternative second embodiment of a closure element 51, which largely corresponds to the first embodiment, so that identical and similar components are given the same reference numbers. The second embodiment of the closure element 51 can also be regarded as an independent subject matter of the invention, independently of the embodiment of the arched end wall. The second exemplary embodiment differs only in that the first and second latching lugs 58, 59 are arranged offset from one another not only axially but also in the circumferential direction. Each detent 58, 59 is assigned an overlying opening 72 in the cap plate 52. Thanks to these measures, the closure element 51 can be produced without forced demoulding using a simple two-part injection molding tool, the tool parts of which are brought together and apart along the longitudinal axis 73 of the closure plug 55 . In the figs. 13 and 14 an alternative third embodiment of a closure element 51 is shown, which largely corresponds to the first and second embodiment, so that identical and similar components are denoted by the same reference numbers. The third embodiment of the closure element 51 can also be regarded as an independent subject matter of the invention, independently of the embodiment of the rest of the ventilation device 16 . The third exemplary embodiment is distinguished in comparison to the other exemplary embodiments in that six pocket-shaped recesses are formed by reducing the wall thickness in the circumferential direction between the six sections with the locking lugs 58, 59, which serve as air ducts 60 or lead to an enlargement of the air ducts 60 , when the closure element 51 is arranged in the maximum open position on the flow cup 11. Furthermore, the rigidity of the hollow collar 53 is specifically adjusted by the pocket-shaped recesses.

The cap plate 52 of the closure element 51 has a plurality of openings 72 like the exemplary embodiment according to FIG. An opening 72 in the cap plate 52 is assigned to each detent 59 . Thanks to these measures, the latching lugs 59, which are particularly important for functionally reliable holding of the closure element 51 in the closed position, can be produced without forced demoulding and tool-related using a simple two-part injection mold, the tool parts of which are brought together and apart along the longitudinal axis 73 of the closure plug 55 will. The latching lugs 58, which are arranged offset only axially but not in the circumferential direction with respect to the latching lugs 59, are produced by forced demoulding. Four circular imprints are visible on the cap plate 52, which originate from the ejectors of the injection molding tool for producing the closure element 51.

It can be seen from FIGS. 1 and 9 that the aeration device 16 is arranged on the outside of the end wall 71 of the flow cup 11, which is provided with a bulge extending evenly over the end wall 71 extends. In particular, there is a concave curvature towards the interior of the material container 13.

The point 74 of the concave end wall 71, which protrudes furthest inward due to the concavity, has an offset or a depth of 1% to 4%, more precisely 2% to 3% of the diameter of the end wall compared to the outer edge region of the end wall 71 71 on. In the embodiment shown, the diameter is z. B. d = 84.6 mm and the (height) offset z. B. V = 2.0 mm.

A peripheral wall 75 of the flow cup 11 adjoins the arched end wall 71. The surrounding wall 75 is closed by the arched end wall 71. The peripheral wall 75 is conical to such an extent that the concave end wall 71 (despite the concavity) adjoins the peripheral wall 75 at an angle of greater than 90°. In the exemplary embodiments shown, there is an angle a of approximately 92°.

Due to the proportions in FIG. 1, this can hardly be seen. For a better understanding, reference is therefore made to the exemplary embodiment shown in FIG. The second embodiment is explained in more detail below.

The exemplary embodiment of a gravity cup 11 according to the invention shown in FIG. 9 and FIGS. 10 to 12 largely corresponds to the first exemplary embodiment, so that the same reference numbers are used for identical or similar components.

Overall, the gravity cup 11 according to the second embodiment is designed as an upside-down gravity cup.

The flow cup 11 also has a screw cap 15 and a material container 13 which can be closed in a fluid-tight manner by means of the screw cap 15 . In contrast to the first exemplary embodiment, the outlet connection 12 is on the screw cap 15 and the ventilation device 16 is on the Bottom of the material container 13 arranged. A sieve element receptacle 76 for a flat, disc-shaped sieve element (not shown) is provided in the screw cap 15, analogously to the sieve element 17 shown in FIG. As an alternative to a flat screen element, a cylindrical plug-in screen can be used, which can be fixed in the outlet socket 12 or in the cup connection 2 on the spray gun side. This also applies to the first exemplary embodiment according to FIG. 1 to.

The connection means, by means of which the outlet connection piece 12 can be mounted on a spray gun 1, correspond to the connection means on the outlet connection piece 12 of the first exemplary embodiment, so that reference is made to the corresponding passages in the description of the figures.

The screw connection 22, the aeration device 16 including the arched end wall 71 on which the aeration device 16 is arranged correspond in structure and function to that of the first exemplary embodiment of a flow cup 11, so that reference is also made to the relevant passages.

Based on Figs. 9 to 12 it follows that the concave end wall 71 forms the bottom 14 of the cup-shaped material container 13. In the exemplary embodiment shown, the end wall 71 is produced in one piece with the peripheral wall 75 and the peripheral edge 70 of the material container 13 . Thanks to the conical design of the peripheral wall 75 of the material container 13 and the inward curvature of the end wall 71 forming the base 14, a plurality of material containers 13 can be stacked closely one inside the other.

It can be seen from FIG. 9, which shows a sectional view of the entire flow cup 11, that the closure element 51 of the ventilation device 16 can also serve as a closure element 51 for the outlet connection piece 12. The same applies to the outlet connector 12 of the first exemplary embodiment. In Fig. 10, which shows a perspective top view of the screw cap 15 without the closure element 51 on the outlet socket 12, the compensating ring groove 45, which follows the receiving groove 31 in the screw cap 15, and the connection and sealing means on the outlet socket 12 are in the form of the clamping wedge element 18 and the radial sealing lips 21 are clearly visible.

The Figs. 11 and 12 serve in particular to illustrate the formation of the threaded webs 30, 36 of the screw connection 22 between the screw cap 15 and the material container 13. As already explained, it is a multi-threaded screw connection 22. Four threaded webs 30, 36 are formed on both the cover and the container side. The cover-side threaded ridges 36 are arranged in the receiving groove 31 and each run from the lower edge of the receiving groove 31 to the bottom of the receiving groove 31. The cover-side threaded ridges 36 therefore partially overlap in the circumferential direction. The container-side threaded webs 30, on the other hand, do not overlap in the circumferential direction.

The flow cups 11 according to the first and second exemplary embodiment are preferably made of plastic in a plastic injection molding process, with the screw cap 15 and the material container 13 being formed in one piece apart from the closure element 51 and the sieve elements 17 .

In the case of an exemplary embodiment that is not shown, one or more closure elements 51 and/or one or more sieve elements 17 can also be produced in one piece with the screw cap 15 or the material container 13 . For example, they can be attached at any point by tear-off webs, tabs, film hinges, etc., which can be severed in order to assemble the elements elsewhere.

The material containers 13 are made of polypropylene (PP), for example, and the screw caps 15 are made of high-density polyethylene (HDPE), for example Polypropylene (PP) manufactured. The closure element 51 is also made of high-density polyethylene (HDPE) or polypropylene (PP), for example.

The flow cups 11 according to the invention are preferably extremely thin-walled products. The wall thickness of the material container 13 is in the range from 0.55 mm to 0.65 mm, specifically around 0.60 mm, and the wall thickness of the screw cap 15 is in the range from 0.75 mm to 0.85 mm, specifically 0 .80mm. The only exceptions are accumulations of material at local locations, e.g. B. for the formation of thread flanks, latching and gripping edges or on the outlet nozzle, in particular for the formation of the clamping wedge element 18.

The screw cap 15 of the first exemplary embodiment and the material container 13 of the second exemplary embodiment are preferably produced in an injection molding process, in which the injection point of the components is in each case as centrally as possible on the concave end wall 71 . In order to make this possible, the ventilation device 16 is arranged slightly off-centre. It is arranged with an offset of more than 5% but less than 10% of the diameter of the end wall 71 towards the middle of the end wall 71 .

In FIG. 3, the injection point 77, which also corresponds to the point 74 (FIGS. 1 and 9, maximum curvature), can be seen to the left of the ventilation opening 61 by means of a smaller accumulation of material. In the exemplary embodiment shown, the offset between the eccentric ventilation opening 61 and the central injection point 77 is 5.50 mm, which corresponds to 6.50% for a diameter of the end wall 71 of 84.6 mm.

The flow cup 11 according to the invention and the spray gun 1 equipped with it are suitable for atomizing and applying very different materials. A main area of application is automotive refinishing, in which top coat, filler and clear coat are used and which places very high demands on atomization and the properties of the spray jet. But it can also be a variety of other materials using the flow cup 11 and a possibly modified spray gun 1 are processed. The decisive factor is that the materials are flowable and can be sprayed, at least to a certain extent.

Claims

Expectations

1. Gravity cup (11) for a spray gun (1), which has a Materialausiass for direct and / or indirect connection with a

spray gun (1), the flow cup (11) having a material container (13) which is closed off at least on one end by a disc-shaped end wall (71), a ventilation device (16) being arranged on the outside of the end wall (71). through which air can flow into the gravity cup (11) in order to enable pressure equalization when material flows out of the gravity cup (11) via the material outlet, characterized in that the end wall (71) has an indentation, in particular a concave one Bulge towards the inside of the material container (13), which extends evenly over the end wall (71) of time.

2. Gravity cup (11) according to claim 1, characterized in that the point (74) of the concave end wall (71), which due to the concavity protrudes furthest inwards, is offset relative to the outer edge region of the end wall (71), in particular one

Having a depth of 1% to 4%, preferably 1.5% to 3%, of the diameter of the end wall (71).

3. Gravity cup (11) according to any one of the preceding claims, characterized in that the ventilation device (16) has an eccentric

Ventilation opening (61) through the domed end wall (71) which is arranged towards the center of the end wall (71) with an offset which is preferably greater than 5% and less than 10% of the diameter of the end wall (71).

4. Flow cup (11) according to one of the preceding claims, characterized in that the concave end wall (71) adjoins a peripheral wall (75) of the flow cup (11) at an angle (a) of greater than 90°.

5. Flow cup (11) according to one of the preceding claims, characterized in that a peripheral wall (75) of the flow cup (11) widens conically, starting from the end face which is closed by the concave end wall (71), preferably to an extent that the concave end wall (71) connects to the peripheral wall (75) at an angle (a) of greater than 90°.

6. Gravity cup (11) according to any one of the preceding claims, characterized in that a peripheral edge (70) is provided which protrudes outwards with respect to the concave end wall (71).

7. flow cup (11) according to any one of the preceding claims, characterized in that the ventilation device (16).

Closing element (51) which can be moved between at least one open position in which air can flow into the gravity cup (11) and a closed position in which no air can flow through the ventilation device (16) into the gravity cup (11).

8. flow cup (11) according to any one of the preceding claims, characterized in that a movable closure element (51) of

Ventilation device (16) in a closed position, in which no air can flow through the ventilation device (16) into the gravity cup (11), is set back relative to a peripheral edge (70).

9. flow cup (11) according to any one of the preceding claims, characterized in that a movable closure element (51) of

Ventilation device (16) in an open position, in which air can flow through the ventilation device (16) into the flow cup (11), opposite a peripheral edge (70) protrudes.

10. Gravity cup (11) according to one of the preceding claims, characterized in that the concave end wall (71) is detachably connected to the material container (13), preferably as part of a cover (15) of the gravity cup (11).