Liquid supply cup for spray gun

[0001] The invention relates to a flow cup for a paint spray gun according to the preamble of claim 1.

[0002] Conventional flow cups for paint spray guns usually have a cup-shaped container, at the bottom of which a hole with a connection part is provided for the container to be torn apart on the upper side of the spray gun. The connecting part usually consists of a connecting stub, inserted into the bottom of the container, which has an external thread to be screwed into the corresponding threaded hole on the upper side of the spray gun. The cup-shaped container is usually closed from above with a suitable lid to prevent unwanted paint leakage.

[0003] There are already known from WO 01/12337 A1, WO2004 / 037433 A1, EP 1 366 823 A1 and EP 1902786 A1 flow cups which comprise a cup-shaped container and a lid fitted thereon with a hollow cylinder-shaped connection part. In this connection, the connection part comprises a connection stub, directly formed on the cup cover, for quick connection of the flow cup to the spray gun. Further, in the case of the flow cup of EP 1902786 A1, a fast closing thread is provided in the form of a four-stroke rigid thread with external thread pitch on the upper outer periphery of the container and corresponding internal thread pitch on the inside of the lid for sealing the lid to the cup-shaped container. The four outer thread strokes on the container are evenly distributed along the outer periphery of the container and positioned so that the start of one thread pitch lies directly above the end of the next thread pitch. Thanks to this, you can firmly screw the lid with the container for about a quarter turn.

[0004] Due to the fact that on the outer periphery of the container, the rigidity of the sealing edge of the cup is not homogeneous, and with the injection molding of the container, wall thicknesses are formed which are unevenly distributed around the perimeter, the containers known from the state of the art tend to leak, especially with local deformation when the container is being squeezed by hand in the area of ​​the upper edge.

[0005] The object of the invention is to further develop the flow cups of the type mentioned at the outset so that they have an improved seal between the container and the lid placed on it.

[0006] This task is solved by a flow cup with the features of claim 1. The intentional embodiments and preferred forms of further development of the invention are the subject of the dependent claims.

[0007] In the case of a flow cup according to the invention, which has a cup-shaped container and a lid disposed on the container, a several-step quick-closing thread with at least two external thread strokes and cooperating with the external thread strokes are provided for connecting the container and the lid. each external thread pitch being formed by several thread segments located along the rising line of the respective external thread pitch. A gap is formed between adjacent thread segments. Thanks to this, wall thickness accumulation arising at the injection molding in the area of ​​the external thread pitch can be avoided to a large extent and the upper edge of the container has the same rigidity around the entire outer circumference, which leads to improved tightness when the lid is screwed onto the container by means of a quick closing thread .

[0008] The outer thread pitch is usually formed on the upper outer periphery of the container, and the inner thread pitch is located on the lid. But it is also possible to place the outer thread pitch on the lid and the inner thread pitch on the outer circumference of the container. Furthermore, at least one guide ramp is foreseen for each pitch of the external thread, which enables an improved and especially light screwing process when screwing the lid onto the container. The guide ramp (guide ramps) are intentionally located on the upper side of each external thread pitch, especially on the upper side of two adjacent thread segments. In one preferred embodiment, the guide ramps are located between two adjacent thread segments, i.e. over the gap, and bridge the two adjacent thread segments.

[0009] In one preferred embodiment, the internal thread pitch is positioned on the inside of the flange at the cover and tapers around the inside perimeter of the collar in the closing direction of the quick closing thread in the axial direction. When applying the lid to the edge of the container, the guide ramps, located on the upper side of each pitch of the external thread, act as a guide aid and with the twisting of the fast closing thread, the guide ramps engage with the pitch of the internal thread on the lid and wedge there due to the narrowing of the pitch of the internal thread in closing direction of the fast closing thread. This guarantees the stability of the twisted quick-closing thread, which cannot be loosened again, e.g. by vibration during spraying.

[0010] Further particularities and advantages of the invention result from the following description of the preferred embodiment based on the drawing. The figures show:

Figure 1 a flow cup according to the invention with a cup-shaped container and the lid attached thereto;

Figure 2 a view of the cup-shaped container and the flow cup cover of Figure 1 with a quick closing thread for screwing the cover onto the container;

Figure 3 a detailed view of the area X of figure 2;

Figure 4 a detailed view of the area Y of figure 2 and

Figure 5 a detailed view of the area Z of Figure 2;

Figure 6 detailed view of the transition area of ​​the fast closing thread pitch for the next thread pitch;

Figure 7 a cross-sectional view along the line AA of Figure 6.

[0011] The flow cup for a paint spray gun, shown in figure 1, comprises a cup-shaped container 1 and a lid 2 applied thereto, at which a connection part 3 is formed for the separable attachment of the flow cup on the spray gun. Both the container 1 and the lid 2 with the shaped attachment part 3 are intentionally made of plastic as injection-molded parts. In figure 2 the flow cup is shown with the lid 2 removed from the container 1 in cross section. The cup-shaped container 1 is in the position shown in figure 2, with the lid 2 removed, filled with liquid, sprayed with a spray gun, especially a varnish. Then cover 2 is put on the upper edge of the container and screwed to the container with a quick-closing thread. Then the flow cup can be inserted with the connection part 3 formed at the lid 2 in the connection opening of the inverted spray gun. Then, for spraying, the spray gun can be turned over so that the flow cup is on the upper side of the spray gun. To enable venting of the flow cup, a vent valve, not shown here, is provided, which is intentionally positioned at the bottom 4 of the container 3 and shaped so that it can be closed. The vent valve, which can be closed again after use, offers the advantage that the flow cup can also be used to store paint that has not been used up.

[0012] The connecting part 3 consists of a connecting piece 5 in the form of a pipe, injection-molded with a conical cover 2 or shaped differently thereon, which includes a front guide area 6 in the shape of a hollow cylinder, followed by an external thread 7 for screwing into a conventional internal thread , and behind the external thread 7 a screw wedge element 8 for quick connection of the flow cup to the spray gun.

For sealing the container 1 to the lid 2, as shown in figure 2, a four-stroke fast closing thread is provided with the outer thread 18, 18 'shaped on the upper outer circumference of the container 1 and the corresponding internal thread pitch 19 on the lid 2 The four pitches of the outer thread 18, 18 'are evenly distributed along the outer circumference at the upper edge of the container 1. Each pitch of the outer thread 18, 18 'is formed by several thread segments 18a, 18b, ..., 18e, 18f, ..., 18j located along the rise line 10 of the respective pitch of the outer thread 18, 18', with adjacent the thread segments are a gap 18p, 18q, 18r, each pitch of the external thread

18, 18 'has at least two thread segments 18a, 18b and usually 4 to 10 thread segments. In the embodiment shown in figure 2, 9 thread segments 18a, 18b, ..., 18e, 18f, ..., 18j are provided for one pitch of the external thread 18, 18 '.

[0014] Each pitch of the outer thread 18, 18 'has a guide ramp 16. Each guide ramp 16 is positioned at the upper edge of two adjacent thread segments 18e, 18f the pitch of the outer thread 18, 18', as shown in figure 5. The guide ramp 16 connects with this bridge both adjacent thread segments 18e, 18f.

[0015] The internal thread pitch 19 is located on the inside of the flange 11 at the cover 2 (Fig. 3). Each internal thread pitch 19 is limited by the first bridge 12 and the second bridge 13. The bridges 12, 13 protrude from the inner surface of the flange 11 and run obliquely at an elevation angle corresponding to the elevation angle of the external thread pitch 18, 18 ', along the inner periphery of the collar through the limited angular area. The number of pairs of bridges 12, 13, limiting the internal thread pitch, corresponds to the number of external thread pitch 18, 18 '. In the illustrated embodiment, four outer threads 18, 18 'are provided and four inner threads 19 respectively. In this embodiment, the bridges 12, 13 run through approx. 150 ° along the inner circumference of the flange 11, with the beginnings and ends of the bridges 12, 13 are placed relative to each other at an angle of approx. 90 ° and the first bridge 13 first form the lower bridge of one internal thread pitch, and then go to the upper bridge 12 of the adjacent internal thread pitch. The bridges 12, 13 slightly converge in the closing direction of the fast closing thread, so that the width of each pitch of the internal thread 19 slightly decreases in the axial direction.

[0016] To improve the stiffness of the edges, an edge flange 9, thickened relative to the walls of the container 1a, is provided at the upper edge of the container 1. The four pitches of the outer thread 18, 18 'are usually positioned at this edge flange 9 such that the end 20 of one pitch of the thread 18 lies directly above the start 21 of the next pitch of the thread 18', as shown in Fig. 6. The distance between the end 20 of one thread pitch 18 and the beginning 21 of the next thread pitch 18 'is, for example, 4-6 mm. The fast closing thread is usually made as a rigid thread, rising for example by 20 mm. This allows the lid 2 to be firmly screwed on to the container 1 for about a quarter of a turn.

[0017] As can be seen from figure 7, further in the example shown the thread is shaped as a trapezoidal thread with edges at an angle of about 30 °. But the quick-release thread can also be made as a round, pointed or other suitable profile. In a preferred embodiment, the outer diameter d of the outer thread is between 100 and 110 mm, usually around 105 mm, and the inner diameter D of the outer thread is between 90 and 105 mm, usually around 102 mm. The width b of the thread pitch on the outside is in this embodiment from 1.1 - 1.3 mm.

[0018] When applying the cover 2 to the container 1, the lower edge of the upper bridges 12 internal thread pitch lies first on the upper edge of the external thread pitch 18, 18 '. By turning the lid 2 relative to the container 1 in the closing direction of the fast closing thread, the outer thread strokes 18, 18 'mesh with the inner thread 19, wherein the guide ramps 16 serve as a guide and prevent edge displacement. With further rotation of the cover, the guide ramps 16 engage with the internal thread pitch 19 and tighten there - due to the narrowing of the internal thread pitch - between the upper bridge 12 and the lower bridge 13. The lower edge of both thread segments 18e, 18f above which is located the guide ramp 16 creates an opposite bearing at the upper edge of the lower bridge 13.

Further on the inside of the lid 2 there is a wedge-shaped sealing bridge 22 shown in figure 5, which between the outside and the inside of the lid 2 delimits the wedge-shaped ring groove 23 for inserting the upper edge of the container 24. Due to the groove of the ring 23, tapering wedge upwards in figure 5, when the lid 2 is screwed on, the upper edge of the container 24 is pressed outwards towards the inner wall of the lid flange 11, whereby a sealing seal is formed. The sealing bridge 22 is high enough to capture paint that is still in the cover when removing the cover and prevent it from flowing into the internal thread.

[0019] The invention is not limited to the embodiment described above and shown in the drawing. Thus, for example, the number of lead threads 18, 18 'and lead thread 19 may be variable. You can also choose a different number of thread segments for the outer thread pitch, with at least two thread segments per outer thread pitch. The outer thread pitch can also be placed on the top edge of the container, and the outer thread pitch on the lid. Further, the internal thread pitch can also be formed in the form of grooves on the inner surface of the flange 11 or on the upper surface of the circumference of the container 1. The lid-container connection according to the invention can also be used e.g. in flow cups, in which the connector for connecting the flow cup to the spray gun is placed not in the lid but in the bottom of the container. Further, in an embodiment in which the connection stub is formed in the lid, a roll-up paint insert can be inserted into the container, which is attached at the upper edge of the container.

Dorota Rzążewska

Patent Attorney