FLUID RESERVOIR FOR A SPRAY GUN WITH A SCREW CAP

FIELD OF THE INVENTION

The invention relates to a flow cup for a spray gun, which has a material outlet which is embodied for direct and/or indirect connection to a spray gun, the flow cup having a material container and a screw cover that closes the material container, a peripheral region of the material container while configuring a screw connection to be disposed in a receptacle groove on the cover for the releasable and fluid-tight connection of material container and cover.

Furthermore, the invention relates to a screw cover or a material container of a flow cup of this type.

BACKGROUND

A flow cup according to the type mentioned at the outset is disclosed in WO2009/090273 A1, for example. The cup described therein has a material container and a cover with which the material container can be closed. In order to use the cup with a spray gun, the material container is first filled with a coating material to be applied. The material container filled with the coating material is subsequently closed by means of the cover. For this purpose, the cover is placed on the material container, with the upper periphery of the material container being introduced into a receptacle groove in the cover. The flow cup known from WO2009/090273 A1 is a cup with a screw cover, i.e. the cover is attached to the material container by a rotating movement. A screw connection holds the cover on the material container, a fluid-tight connection between material container and cover being produced after screw-fitting.

The flow cup has a material outlet. In the case of WO2009/090273 A1, the material outlet is provided on the cover. This is a so-called upside-down flow cup, which is mounted on the spray gun with the cover facing down. The coating material can flow from the material container, through the material outlet on the cover, into the spray gun due to the effect of gravity. In the case of compressed-air atomizing spray guns, the coating material is additionally suctioned from the cup to the nozzle by negative pressure generated at the atomizing nozzle.

The fact that the periphery of the container is disposed in the receptacle groove in the cover results in a robust and tight connection between the cover and the container. This is particularly necessary by virtue of the high forces that during painting work arise e.g. by pivoting, tilting and moving back and forth of the assembly of the spray gun and the flow cup assembled on the latter.

In this context, it is also advantageous that the cover is embodied as a screw cover, since a screw connection, in contrast to a snap-fit connection, for example, is distinguished by a high degree of robustness against lateral forces due to impacts or very rapid pivoting movements. Moreover, the assembly and disassembly of a snap-on cover entails vibrations of the cover and of the material container, which in turn increase the risk of uncontrolled, sudden detachment of paint residues from the surface of the cover or material container and associated spattering. A screw cover, on the other hand, can be repeatedly attached and removed in a uniform manner without vibrations.

Flow cups are consumables. Depending on the construction mode, the cups may indeed be used several times. Nevertheless, a large number of cups are constantly consumed in paint shops. It is therefore a price-sensitive mass product.

SUMMARY OF THE INVENTION

One aspect of the invention relates to refining the known flow cup from the point of view of its suitability for cost-conscious mass production.

The flow cup according to the invention is characterized in that a central region of the screw cover, which adjoins the receptacle groove for the container periphery, is embodied as a continuation of a predominant part of the inner leg of the receptacle groove.

Unlike in the prior art, the inner leg of the receptacle groove is not embodied as a free-standing web or collar, but rather the central region of the screw cover transitions into the inner leg. At the other end, the inner leg preferably transitions into a central connecting web that forms the base of the receptacle groove. The central connecting web preferably in turn transitions into the outer leg of the receptacle groove.

The design embodiment of the inner leg according to the invention has considerable manufacturing advantages. Components of flow cups are advantageously produced from plastics material by an injection-molding method. In terms of the plastics injection-molding method, the invention is distinguished in that the liquid plastics stream is not divided at the transition from the central region of the screw cover to the receptacle groove when the injection-molding tool is being filled. Thanks to the invention, the region that is particularly sensitive to the functional reliability of the cover, specifically the receptacle groove, can be formed by a uniform (non-bifurcated) flow of liquid plastics material coming from the central region. This ensures that the injection-molding tool is filled quickly, uniformly and completely in this particularly critical peripheral region of the cover. As a result, the cycle times and also the wall thicknesses of the screw cover can be reduced without any loss of functionality, which in turn leads to overall cost and material savings.

Independently of the production method, the invention also leads to an increase in functional reliability or allows a reduction in wall thickness and thus material savings. Since the inner leg of the receptacle groove is not embodied to be free-standing, but rather its end is connected to the central region of the cover, the inner leg is supported or stiffened by the central region of the cover, which in turn allows the wall thickness to be reduced while maintaining or even increasing stiffness.

In order to obtain the advantages according to the invention, the central region does not have to be attached to the end of the inner leg (even if this is particularly preferable). The advantages of the invention are indeed derived to a reduced degree, but still to a considerable degree, if a major part of the inner leg, e.g. more than 50%, preferably more than 75%, more preferably 95% of the total length of the inner leg (spacing from the base of the groove to the outer edge of the inner leg) is embodied as a continuation of the central region. Conversely, this means that less than 50%, preferably less than 25%, more preferably 5% of the total length of the inner leg is configured as a free-standing or projecting collar, rib, bead, lip, etc.

In the case of a particularly preferred embodiment, the central region of the cover adjoins the receptacle groove by way of an annular portion which extends at least almost perpendicularly to the receptacle groove. This constructive measure reinforces the explained supporting effect of the inner leg by the central region.

Preferably, the at least almost perpendicular annular portion is followed by an annular portion of the central region, which runs at least almost parallel to the inner leg, specifically in such a manner that a further groove is formed, but said groove is open in the opposite direction of the receptacle groove. A compensating ring groove is formed by the further groove, and the desired support or rigidity of the inner leg can be defined via the dimensioning of this groove.

For reasons of stability and stiffness, a refinement of the invention is preferred in which the peripheral region of the material container, which for configuring the connection between the material container and the cover is to be disposed in the receptacle groove on the cover, is provided with an eversion which is preferably additionally reinforced by means of radial transverse ribs.

The transverse ribs preferably terminate so as to be at least almost flush with the outer (lower) periphery of the eversion.

In the case of a particularly preferred exemplary embodiment, the cover is embodied as a screw cover which is provided with at least one threaded element which with at least one corresponding threaded element on the material container forms a screw connection. The at least one threaded element on the cover and/or on the material container is preferably embodied as a threaded web. A functionally reliable connection is guaranteed in this way and at the same time material accumulations can be avoided and minor wall thicknesses can be achieved in the region of the threaded elements.

If necessary, the threaded webs can be embodied with an angle profile to further increase the functional reliability of the connection.

It has proven successful in practice that for forming the screw connection an internal thread is provided on the cover and a corresponding external thread is provided on the material container.

A fixed screw connection that is bordered on both sides in the receptacle groove and thus well supported is obtained by disposing the at least one cover-proximal threaded element inside the receptacle groove.

In particular, the at least one threaded element of the cover is disposed on the inside of an outer leg of the receptacle groove and/or the at least one threaded element of the material container is disposed on the outside of an outer leg of an eversion of the peripheral region of the material container.

In terms of injection-molding, an exemplary embodiment of the invention in which the at least one threaded element, which is disposed inside the receptacle groove, transitions into the central connecting web of the receptacle groove, which forms the base of the receptacle groove, is advantageous. In this way, the threaded element or the threaded elements can be molded in the interior of the receptacle groove, for example, by an injection-molding tool with a rotary core.

The screw connection is preferably embodied as a multi-threaded screw connection.

In particular, an exemplary embodiment in which a plurality of, in particular four, threaded webs of the same type are provided both on the cover side and on the material container side, is preferable. The cover-proximal threaded webs, for example, are provided inside the receptacle groove and preferably all transition into the base of the groove. Advantageously, these threaded webs can overlap in the circumferential direction, with the threaded webs running axially offset from one another in the overlapping region.

In the case of a particularly preferred exemplary embodiment, the cover in the closed state of the flow cup encompasses the material container, in particular said cover completely (axially and/or radially) encompasses an eversion of the peripheral region of the material container.

High demands are placed on the sealing of the connection between the cover and material container of a flow cup. With the flow cup, different coating materials are processed, sometimes with significant amounts of solvent. The seal must reliably prevent even small amounts of material from escaping, even if the coating material is stored for a longer period of time and internal pressure builds up in the flow cup. The sealing effect must be guaranteed at all times, even if the flow cup is opened and closed repeatedly and the seal is contaminated with the coating material (paint) it contains.

In view of the high requirements, an exemplary embodiment in which the fluid-tight sealing between the cover and the material container takes place by way of components bearing in an encircling tight manner in the interior of the receptacle groove is particularly preferable.

The fluid-tight sealing between the cover and the material container is preferably achieved by the components bearing in an encircling sealing radial and/or axial manner.

In the case of a particularly preferred exemplary embodiment, the fluid-tight sealing between the cover and the material container is implemented by bearing in an encircling sealing manner on the outside of the inner leg of the receptacle groove and/or by bearing in an encircling sealing manner on the central connecting web of the receptacle groove, which forms the base of the receptacle groove.

One or more encircling sealing beads, ribs, lips etc. on at least one of the contact surfaces on the cover and/or on the material container can further increase the sealing effect and its functional reliability. A variant in which a plurality of axially offset, encircling sealing beads are provided on the outside of the inner leg of the receptacle groove, which bear in a sealing manner against the inside of the material container, in particular in the region of the eversion, is particularly preferable. The sealing beads, ribs, lips, etc. can also be formed on the base of the receptacle groove (central connecting web), inside of the outer leg, the inside or outside of the eversion and/or its end side.

The stability of the cover/material container connection and optionally the functional reliability of the seal is increased in a preferred exemplary embodiment in that, when the container periphery is inserted into the receptacle groove, at least the peripheral region of the material container expands on the outside of the inner leg of the receptacle groove.

In the case of a particularly preferred exemplary embodiment, the connection between the cover and the material container is embodied in such a way that if the components swell under the influence of the coating material contained in the flow cup, the sealing effect between the cover and the material container is reinforced. The swelling results in particular from the penetration of solvents into the material of the cover or container. The cover material can show a different swelling behavior than the container material in the process. This in turn can result in the sealing effect between the cover and the container decreasing due to the swelling, as a result of which the dimensions of the components bearing on one another change. A particularly preferred refinement of the invention reduces the risk of swelling in that the cup periphery (in particular the eversion) is firmly enclosed or clamped radially on the inside and outside in the receptacle groove on the cover. Furthermore, the already mentioned expansion of the cup periphery on the outside of the inner leg of the receptacle groove counteracts a reduction in the sealing effect due to swelling.

The flow cup according to the invention is preferably an extremely thin-walled product. Thus, the wall thickness of the material container is in the range from 0.55 mm to 0.65 mm, for example, preferably is 0.60 mm, and/or the wall thickness of the screw cover is in the range from 0.75 mm to 0.85 mm, for example, preferably is 0.80 mm.

The flow cup is preferably embodied as a “standard flow cup”, i.e. the central region of the cover is closed, apart from any ventilation device or similar that may be present, and/or the material container is cup-shaped with a base, the base being provided with a (funnel-shaped) material outlet.

In the case of a particularly preferred embodiment, the flow cup is embodied as an upside-down flow cup. The removable screw cover is provided with a material outlet for mounting on a spray gun, which preferably comprises a tubular outlet port, and/or the base of the cup-shaped material container is configured in such a manner that the material container can be placed on a flat surface with the base downward for filling and any mixing, without any additional tools.

In a particularly preferred exemplary embodiment, the central region of the screw cover has a funnel-shaped section and/or the central region of the screw cover has an outlet port, which in turn can preferably be connected directly or indirectly to a spray gun.

As already mentioned, the cover and the material container are preferably made of plastic in an injection-molding method. It is particularly advantageous if the cover and/or the material container are produced as integral plastic injection-molded parts. It goes without saying that the cover and the material container are also to be regarded as an integrally produced component 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. integrally with the cover or the material container. However, this is entirely conceivable and technically feasible.

In order to enable pressure equalization in the material container when the coating material flows out, a ventilation device is provided in variants of the invention. The ventilation device can be disposed in the cover or in the material container, preferably in the base of the material container.

The invention is further implemented by a screw cover or a material container embodied for use as part of a flow cup having the features described above and below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained hereunder by means of exemplary embodiments. In the figures:

FIG. 1 shows a sectional view of a spray gun with a flow cup according to a first exemplary embodiment of the invention;

FIG. 2 shows a partial sectional view of the flow cup according to FIGS. 1 and 9 in the region of the connection between the cover and the material container of the flow cup;

FIGS. 3 to 5 show partial sectional views of the flow cup according to FIGS. 1 and 9 in the region of the ventilation system in three different states;

FIGS. 6 and 7 show a perspective and a lateral view of the closure element of the ventilation device of the flow cup according to FIGS. 1 and 9;

FIG. 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;

FIG. 9 shows a sectional view of a flow cup according to a second exemplary embodiment of the invention;

FIGS. 10 and 11 show a perspective and a sectional view of the cover of the flow cup according to FIG. 9; and

FIG. 12 shows a perspective view of the material container of the flow cup according to FIG. 9.

DETAILED DESCRIPTION

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 configured, for example, as a so-called high-pressure, compliant or HVLP spray gun 1. The spray gun 1 has a cup connector 2 and a nozzle head 3 at which the coating material supplied to the spray gun 1 via the cup connector 2 is atomized and emerges in the form of a spray jet.

Furthermore, the spray gun 1 comprises a handle 4, a trigger 5 for actuating a material needle 10 disposed 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 adjusting device 8 and a compressed air connection 9. By means of the round/broad jet adjustment device 8, the distribution of the compressed air supplied to e.g. an atomization and transport air on the one hand and a horn air for a wide beam formation on the other hand can be changed.

A flow cup 11 is connected to the cup connector 2 of the spray gun 1 by means of a material outlet configured as an outlet port 12. The flow cup 11 has a material container 13 on the base 14 of which the outlet port 12 is molded. Furthermore, the flow cup 11 comprises a screw cover 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 port 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 port 12.

The outlet port 12 is equipped with connection means in the manner of a bayonet lock, which include a clamping wedge element 18 protruding radially from the outlet port 12. The clamping wedge element 18 engages in a corresponding receptacle groove 19 on the spray gun 1. The outlet port 12 seals axially e.g. by means of its end side 20 on the cup connector 2 and/or radially with the aid of two circumferential radial sealing lips 21 (barely visible in FIG. 1 due to the proportions, see also FIG. 10).

The flow cup 11 according to FIG. 1 is embodied as a standard flow cup.

The screw connection 22 between the screw cover 15 and the material container 13 is described in detail below with reference to FIG. 2. FIG. 2 shows an enlarged section of the flow cup 11 according to FIGS. 1 and 9 in the region of the connection point between screw cover 15 and material container 13.

The peripheral region of the material container 13 is provided with an eversion 23 which is reinforced by means of a plurality of radial transverse ribs 28. The transverse ribs 28 terminate almost flush with the outer periphery of the eversion 23. Alternatively, the transverse ribs 28 can also be embodied lower and in the eversion 23 set back somewhat in relation to the outer periphery of the eversion 23.

The eversion 23 has an outer leg 24, a central connecting web 25 and an inner leg 26. The inner leg 26 transitions into a circumferential wall 27 of the material container 13. A section through a radial transverse rib 28, which is molded so as to be integral to the outer and the inner leg 24, 26 and the central connecting web 25 is shown in FIG. 2. The dotted lines in FIG. 2 indicate the profile of the outer and inner leg 24, 26 and of the central connecting web 25.

Four threaded elements in the form of threaded webs 30 are provided on the outside of the outer leg 24 of the eversion 23. The threaded webs 30 are structurally identical to the threaded webs 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 of identical design and is therefore also shown in FIG. 2.

The peripheral region of the screw cover 15 has a receptacle groove 31 which is likewise 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 receptacle groove 31 encompasses the eversion 23 in the peripheral region of the material container 13.

Inside the receptacle groove 31, more precisely on the inside of the outer leg 32, four threaded webs 36 are formed, which conjointly with the threaded webs 30 on the material container 13 form the multi-threaded screw connection 22. All four threaded webs 36 begin approximately at the lower periphery of the outer leg 32 and open into the central connecting web 33 which forms the base of the receptacle groove 31. The threaded webs 36 therefore partially overlap in the circumferential direction, but are axially offset from one another in the overlapping region. This can also be seen from FIG. 2, which shows two threaded 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 cover of the second exemplary embodiment, in which the screw connection 22, as already mentioned, is of identical embodiment.

The fluid-tight sealing between screw cover 15 and material container 13 is performed by radial and axial bearing in an encircling sealing manner in the inside of the receptacle groove 31. Specifically, the radial sealing occurs between the outside of the inner leg 34 of the receptacle groove 31 and the inside of the inner leg 26 of the eversion 23 of the material container 13. The axial sealing takes place between the upper side of the central connecting web 33 of the eversion 23 and the lower side of the central connecting web 25 of the receptacle groove 31.

In an exemplary embodiment that is not shown, analogously to the exemplary embodiment according to FIG. 2, radial sealing can take place between the outside of the inner leg 34 of the receptacle groove 31 and the inside of the inner leg 26 of the eversion 23 of the material container 13, but instead of the additional axial sealing, no, or radial sealing (and supporting) between the inside of the outer leg 32 of the receptacle groove 31 and the outside of the outer leg 24 of the eversion 23 of the material container 13 may take place. The second radial sealing and, if necessary, supporting action can preferably take place near the corner region at the transition from the outer leg 24 to the central connecting web 25 of the eversion 23.

In a further exemplary embodiment that is not shown, analogously to the exemplary embodiment according to FIG. 2, radial sealing can be provided between the outside of the inner leg 34 of the receptacle groove 31 and the inside of the inner leg 26 of the eversion 23 of the material container 13, wherein the sealing action takes place along an encircling and almost linear bearing action between the outside of the inner leg 34 of the receptacle groove 31 and the inside of the inner leg 26 of the eversion 23 of the material container 13 in the region of the lower end of the inner leg 34 of the receptacle groove 31. Additional axial sealing analogously to the exemplary embodiment according to FIG. 2 may or may not be provided in this embodiment. By way of example, three encircling sealing ribs 41 are shown in FIG. 2, which are molded on the outside of the inner leg 34 of the receptacle groove 31 and lead to a further reinforcement of the sealing effect. Moreover, the sealing effect is improved in that the inner diameter of the material container 13 in the upper peripheral region is selected in such a manner that the material container 13 is expanded when the screw cover 15 is installed, at least in the region of the eversion 23, and this results in a particularly strong and sustained radial compression between the screw cover 15 and material container 13.

It goes without saying that, alternatively or additionally, 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 sealing can take place between the screw cover 15 and the material container 13.

A central region 42 of the screw cover 15 is embodied as a continuation of the inner leg 34 of the receptacle groove 31. In FIG. 2 only an outer portion of the central region 42 of the screw cover 15 is shown. In particular, the inner leg 34 is followed by a first annular portion 43 of the central region 42 which extends at least almost perpendicularly to the receptacle groove 31. The annular portion 43 is followed by a second annular portion 44 of the central region 42 which runs at least almost parallel to the inner leg 34, specifically in such a manner that a compensating ring groove 45 is formed which is open in the opposite direction to the receptacle groove 31. By means of the compensating ring groove 45 e.g. manufacturing tolerances of the components can be compensated, in particular to ensure the functionality, strength and tightness of the screw connection 22. Moreover, a desired support or stiffness of the inner leg 34 can be defined via the dimensioning of the compensating ring groove 45.

As can be seen from FIG. 1, the central region 42 of the screw cover 15 in the case of the exemplary embodiment according to FIG. 1 is provided with a ventilation device 16 which enables pressure equalization when coating materials flow out of the flow cup 11 by way of the opposite outlet port 12. 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 explained in more detail in FIGS. 6 and 7.

The ventilation device 16 is embodied as a snap-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 project. The hollow protuberance forms a hollow closure plug 55 which protrudes axially relative to the hollow collar 53 by a distance which corresponds at least almost to the wall thickness of the flow cup 11 in the region of the ventilation device 16 (see also FIG. 6).

The closure plug 55 is provided with an encircling 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 external 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 construction of the closure element 51 is shown in particular in FIGS. 6 and 7, which show the closure element 51 in a lateral view and a perspective top view.

On the outside of the flow cup 11, the ventilation device 16 has a ventilation opening 61 and three hollow collars disposed concentrically to the ventilation opening 61. The outer hollow collar 62 is provided on its open end side with an introduction chamfer 63 for the closure element 51 and a subsequent encircling latching edge 64 on the internal circumference. The central hollow collar 65 forms a separate centering, retaining and guiding device. On the open end side thereof, said central hollow collar 65 is provided with a centering chamfer 66 on the external circumference. The inner hollow collar 67 forms the periphery of the ventilation opening 61 and on its open end side is provided with a centering chamfer 68 on the internal circumference.

The outer hollow collar 62 projects 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 projects from the hollow collar 53 on the closure element 51.

To assemble the ventilation device 16, the closure element 51 is introduced into the outer hollow collar 62, which is facilitated by the introduction chamfer 63. The closure element 51 can be attached and thus provided to the user separately from the flow cup 11 or e.g. via a tear-off tab, web, film hinge, etc. to the screw cover 15 or the material container 13 of the flow cup 11. The ventilation device 16 can also be already 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 disposed on the closure element 51, engage behind the encircling latching edge 64 on the outer hollow collar 62 on the outside of the flow cup 11. Due to the interaction of the first latching lugs 58 and the encircling latching edge 64, the closure element 51 is captively 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 embodied in such a way that they are compressed radially with the internal circumferential face of the outer hollow collar 62. But it is also conceivable that further latching means are formed, for example, in the form of a second circumferential latching edge below the front latching 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 periphery 64 on the outer hollow collar 62 and the outer circumferential face 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 flow cup 11 in order to ensure pressure equalization when coating material leaves the material container 13 via the outlet port 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 periphery 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 region 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, the 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 peripheral latching edge 64 with many smaller openings, i.e. segmented, is embodied so that the incoming air can flow through these openings and not (only) through the gap formed by the play between latching edge 64 and the outer circumferential face of hollow collar 53. In this case, play between the latching edge 64 and the outer circumferential face 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 project significantly beyond an outer circumferential periphery 70 of the flow cup 11. An exemplary configuration of the circumferential periphery 70 can be seen in FIG. 1.

Thanks to the protrusion, a user can clearly see when the ventilation device 16 is in the open state. Moreover, when the flow cup 11 is placed on the circumferential periphery 70 with the side equipped with the ventilation device 16 facing down and a user has failed to close the ventilation device 16 beforehand, the closure element 51 is automatically pushed in the direction of the closed position by the deposition surface on which the flow cup 11 is to be deposited. This prevents large quantities of the coating material from accidentally escaping. If the user places the (still) empty flow cup 11 with the ventilation device 16 open on the circumferential periphery 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/she 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. 4. In the course of this first portion of the closing movement, the closure element 51 is guided by an 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 internal circumferential face of the outer hollow collar 62.

In the intermediate position according to FIG. 4, the second latching lugs 59 meet the latching periphery 64 on the outer hollow collar 62. At least almost simultaneously, the end side of the hollow collar 53 impacts the centering chamfer 66 on the central hollow collar 65 and the plug tip 57 hits the centering chamfer 68 on 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 of the closure plug 55 before the closure plug 55 penetrates 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. 5. In this movement portion, the closure element 51 is additionally guided by an interaction of the hollow collar 53 and the central hollow collar 65. Specifically, the internal circumferential face of the hollow collar 53 slides along the outer circumferential face 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 closure plug 55 closes the ventilation opening 61. Said closure plug 55 bears in a sealing manner on the internal circumferential face of the opening 61. 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 side of the hollow collar 53 is disposed 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 interspace between the inner and central hollow collars 67, 65 before the ventilation device 16 is closed, thus preventing said coating material from getting out into the environment.

In particular, the internal circumferential face of the hollow collar 53 can also bear circumferentially tightly against the outer circumferential face 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 side 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 is now set back from the circumferential periphery 70. The closure element 51 is held in a functionally reliable manner in the closed end position by an interaction of the second latching lugs 59 on the hollow collar 53 and the encircling 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 plate 52 and pull it upwards back into the maximum open position according to FIG. 3.

Shown in FIG. 8 is 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 exemplary embodiment differs only in that the first and second latching lugs 58, 59 are disposed offset from one another not only axially but also in the circumferential direction. Each latching lug 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 demolding using a simple two-part injection molding tool, the tool parts of which are converged and diverged along the longitudinal axis 73 of the closure plug 55.

It can be seen from FIGS. 1 and 9 that the ventilation device 16 is disposed on the outside of the end wall 71 of the flow cup 11, which is provided with an indentation which extends evenly over the end wall 71.

The location 74 of the concave end wall 71, which protrudes furthest inward due to the concavity, has an offset of 1% to 4%, more precisely 2% to 3%, of the diameter of the end wall 71 relative to the outer periphery region of the end wall 71. In the embodiment shown, the diameter is e.g. d=84.6 mm and the offset e.g. V=2.0 mm.

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

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. 9. The second embodiment will be explained in more detail below.

The exemplary embodiment of a flow 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 flow cup 11 according to the second embodiment is embodied as an upside-down flow cup.

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

Alternatively, the sieve elements can be fastened by direct welding or injection into the screw cover 15.

The connection means, by means of which the outlet port 12 can be assembled on a spray gun 1, correspond to the connection means on the outlet port 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 ventilation device 16 including the concave end wall 71 on which the ventilation device 16 is disposed also 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 base 14 of the cup-shaped material container 13. In the exemplary embodiment shown, the end wall 71 is produced in one piece with the circumferential wall 75 and the circumferential periphery 70 of the material container 13. Thanks to the conical design of the circumferential wall 75 of the material container 13 and the concavity of the end wall 71 forming the base 14, a plurality of material containers 13 can be stacked closely one inside the other.

From FIG. 9, which shows a sectional view of the entire flow cup 11, it can be seen that the closure element 51 of the ventilation device 16 can also serve as a closure element 51 for the outlet port 12. The same applies to the outlet port 12 of the first exemplary embodiment.

In FIG. 10, which shows a perspective top view of the screw cover 15 without the closure element 51 on the outlet port 12, the compensating ring groove 45, which follows the receptacle groove 31 in the screw cover 15, and the connection and sealing means on the outlet port 12 in the form of the clamping wedge element 18 and the radial sealing lips 21 are clearly visible.

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 cover 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 threaded webs 36 on the cover are disposed in the receptacle groove 31 and each run from the lower periphery of the receptacle groove 31 to the base of the receptacle groove 31. The cover-side threaded webs 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 method, with the screw cover 15 and the material container 13 being integrally molded—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 cover 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 covers 15 are made of, for example hard polyethylene or high-density polyethylene (HDPE) or polypropylene (PP). The closure element 51 is also produced from, for example hard polyethylene or high-density polyethylene (HDPE) or polypropylene (PP).

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 cover 15 is in the range from 0.50 mm to 0.85 mm, specifically 0.60 mm. The only exceptions are accumulations of material at local locations, e.g. for the formation of thread flanks, latching and gripping edges or on the outlet port, in particular for the formation of the clamping wedge element 18.

The screw cover 15 of the first exemplary embodiment and the material container 13 of the second exemplary embodiment are preferably produced in an injection-molding method in which the injection point of the components is located as centrally as possible on the concave end wall 71. In order to make this possible, the ventilation device 16 is disposed slightly off-center. It is disposed 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 is also the location 74 (FIGS. 1 and 9, maximum concavity), to the left of the ventilation opening 61 can be seen from 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, with a diameter of the end wall 71 of 84.6 mm, this corresponds to 6.50%.

The flow cup 11 according to the invention and the spray gun 1 equipped therewith are suitable for atomizing and applying very different materials. A main region 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. However, a large number of other materials can also be processed using the flow cup 11 and a possibly modified spray gun 1. The decisive factor is that the materials are free-flowing and can be sprayed, at least to a certain extent.

FLUID RESERVOIR FOR A SPRAY GUN WITH A SCREW CAP

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