EP3930913B1 - Rear bowl for a spray gun and spray gun with such a rear bowl - Google Patents

Description

The present invention relates generally to the technical field of spray coating objects.

According to one aspect of the invention, this relates in particular to a spray gun for spray-coating objects with powdered coating material. However, the invention is not limited to this, but can also be used for spray guns for spray-coating objects with liquid coating material.

In particular, the invention relates to an optimized rear shell for spray guns, with which the back of a base body of a spray gun can be covered. The pamphlet US 6,536,688 B1 relates to a handle structure for a water spray gun.

The pamphlet US 10,293,351 B2 relates to a spray gun for spraying paint.

The pamphlet GB 2,067,923A relates to another spray gun for high-pressure cleaning.

The pamphlet US 2013/0075497 A1 relates to a handle structure for a water spray gun.

The pamphlet DE 195 38 252 A1 relates to a handle structure for power tools having a handle portion formed integrally with the main body of the power tool.

Spray guns of the type considered herein are already known from the prior art. For example, the document relates EP 0 383 030 A1 a spray gun for spray coating objects with coating powder. The spray gun known from this prior art has a grip part and a gun barrel connected to the grip part.

In the case of powder spray guns in particular, fine powder dust is produced when they are used, which can penetrate into the gun in an undesired manner. With spray guns for liquid coating material, there is a risk of atomized liquid particles being deposited inside the spray gun. Both with powder spray guns and with liquid spray guns, there is a fundamental risk that high-voltage creepage paths will occur at interfaces between the gun parts between high-voltage parts for electrostatic charging of the coating material and gun parts that are to be electrically insulated from it.

A further disadvantage of the spray guns generally known from the prior art is that the handle parts of the spray guns are often not optimally designed from an ergonomic point of view. In addition, the spray guns known from the prior art have the disadvantage that they often do not have the necessary rigidity with regard to bending and torsion.

The invention is therefore based on the object of remedying the problems mentioned.

The object on which the invention is based is achieved by the subject matter of independent patent claim 1, advantageous developments of the spray gun according to the invention being specified in dependent patent claims 2 to 15.

Accordingly, the invention relates in particular to a spray gun which has a grip part and a gun barrel connected to the grip part, with a rear shell being attached to the back of a base body of the spray gun.

The rear shell has a first area designed as a grip shell, which is designed to cover the grip body of the spray gun, in particular on the rear. Furthermore, the rear shell has a second area designed as a cover shell for covering a rear area of the pistol barrel on the back.

At least one connecting element is provided on the second area of the rear shell, via which a detachable connection can be formed, if necessary, with a part that is designed to be complementary thereto, at least in areas.

According to the invention, it is provided in particular that the entire rear shell, together with the at least one connecting element, is designed as a monolithic plastic component, in particular a plastic injection molded part.

The advantages that can be achieved with the invention are obvious: by providing a rear shell designed as a monolithic plastic component, the rear area of the spray gun and in particular the area which connects the grip part of the spray gun to the gun barrel can be made particularly rigid and torsion-resistant, which has a direct effect on simplified handling of the entire spray gun.

In addition, the rear shell formed in one piece means that the entire spray gun can be optimally sealed, since the boundary surface areas through which coating material can pass are minimized.

Another decisive advantage can be seen in the fact that the first area designed as a grip shell is connected in one piece and seamlessly, i.e. monolithically, to the second area designed as a cover shell. In this way, the handle part of the spray gun is ergonomically improved, since there are no disruptive transitions that could possibly lead to injuries to the hand of the operator of the spray gun.

According to embodiments of the present invention, the rear shell can also have a transition area which connects the first area designed as a grip shell to the second area designed as a cover shell. In this embodiment, the transition area together with the first area designed as a grip shell and the second area designed as a cover shell is designed overall as a monolithic plastic component.

According to preferred implementations of the rear shell according to the invention, it is provided that the first area designed as a handle shell is approximately U-shaped or V-shaped in cross section, at least in some areas, and has a rear wall and two side walls integrally formed thereon. Here, it makes sense if the outer surfaces of the rear wall and the side walls formed on it as a grip shell formed first area, at least in some areas, have a configuration that is adapted to increase grip security, and in particular have a quality.

According to preferred realizations of the rear shell according to the invention, the outer surfaces of the rear wall and the side walls formed thereon of the first area designed as a grip shell have a polygonal wave shape, which is particularly adapted to the hand of the operator of the spray gun.

This embodiment is based on the knowledge that when gripping the handle part of the spray gun, the operator inevitably bends or has to bend the fingers of the gripping hand at least partially. Therefore, from an ergonomic point of view, an optimal shape of the grip part or of the first area designed as a grip shell is an ergonomic multi-edged corrugated shape in order to create a perfect grip.

Of course, the invention is not limited to such special configurations of the first area designed as a grip shell.

According to embodiments of the rear shell according to the invention, at least one cable strain relief is preferably integrated in the rear wall of the first area designed as a grip shell. Due to the fact that in this embodiment the cable strain relief is integrated in the rear shell and specifically in the rear wall of the first area designed as a grip shell, the spray gun can be made particularly compact.

With regard to the second area of the rear shell designed as a covering shell, embodiments of the present invention provide that this area is approximately U-shaped in cross section, at least in some areas, with a rear wall and two side walls integrally formed thereon. According to embodiments of the rear shell according to the invention, the second area designed as a cover shell also has an upper wall that is at least partially or partially opposite the first area designed as a handle shell. This upper wall is integrally formed on the rear wall and the side walls formed thereon of the second area designed as a covering shell.

In this case, it makes sense for the at least one connecting part to be integrally formed on this upper wall. A hook-shaped or eye-shaped element is particularly suitable as the connecting part.

According to advantageous developments of the rear shell according to the invention, at least one in particular recessed opening for at least one control element and/or at least one display element of the spray gun is provided in the rear wall of the second area designed as a cover shell. The at least one opening is designed in particular to accommodate and/or embed the at least one control element and/or the at least one display element of the spray gun in a recessed manner in order to ensure optimal protection of the control element or the display element, while at the same time the penetration of coating material in the edge area of the opening is effectively prevented.

As an alternative or in addition to this, it is conceivable that in the rear shell and preferably in a side wall of the second area designed as a cover shell at least one receptacle for a switch or the like and preferably an integrally formed element that is movable relative to the rear shell for actuating a switch or the like is formed, in particular formed integrally.

With these developments, various functionalities can thus be integrated into the monolithic rear shell.

In preferred embodiments, for example, at least one galvanically conductive grounding element is integrated in the rear shell and preferably in the material of a side wall of the second area designed as a cover shell. The at least one grounding element serves to ground a counter-electrode of the spray gun or to set it to a ground potential. For this purpose, in the assembled state of the spray gun, the grounding element integrated in the rear shell can be connected via a grounding conductor, such as a galvanically conductive connecting web, to a counter-electrode arranged in the vicinity of a charging electrode of the spray gun, in order to connect the counter-electrode to an electrical potential which is different from the electrical potential. to which the charging electrode is connected. In this way, at least part of the free ions generated during the electrical charging of the coating powder can be absorbed via the counter-electrode and the grounding element integrated in the rear shell.

The grounding element integrated in the rear shell is preferably electrically conductively connected to grounding or a potential connection via an electrical line running in particular inside the handle of the spray gun.

In order to facilitate assembly of the spray gun, provision can be made for a centering, in particular in the form of a centering tab or the like, to be provided at least in regions on the front longitudinal edge of the side walls of the rear shell. The centering is designed in particular to bring about an independent alignment of the position of the rear shell relative to the rear of the base body of the spray gun when the rear shell is mounted on the rear of the base body.

Alternatively or additionally, it is advantageous if an at least partially stepped area is implemented at least partially on the front longitudinal edge of the side walls of the rear shell and in particular in or on the face of the front longitudinal edge of the side walls of the rear shell. In this way, an optimal seal with respect to the rear of the base body of the spray gun can be effectively achieved, since a labyrinth sealing area can be formed by the stepped area.

The rear shell can be plugged onto the back of the base body of the spray gun, wherein, according to preferred implementations, only a single screw is sufficient to fix the rear shell to the base body of the spray gun accordingly. This further reduces the risk of coating material entering the spray gun, since only a small number (in the best case just a single) opening for receiving a screw need be provided in the rear shell.

The entire rear shell is preferably designed as a monolithic component made from an antistatic plastic material. As the preferred plastic material Polyamide-12 should be mentioned at this point, although other plastic materials would also be suitable in principle.

An exemplary embodiment of the present invention will be described in more detail below with reference to the accompanying drawings.

Show it:

FIG. 1

schematically and in a side view an exemplary embodiment of the spray gun according to the invention with the optimized rear shell in the assembled state;

FIG. 2

schematically and in an exploded view according to the exemplary embodiment of the spray gun according to the invention FIG. 1 ;

FIG. 3

schematically and in a first isometric view, the exemplary embodiment of the spray gun according to the invention FIG. 1 ;

FIG. 4

shows schematically and in an isometric exploded view the exemplary embodiment of the spray gun according to the invention FIG. 3 ; and

FIG. 5

schematically and in a second isometric exploded view according to the exemplary embodiment of the spray gun according to the invention FIG. 1 .

The spray gun 1 according to the invention, as shown schematically in the drawings using an exemplary embodiment, is used in particular to apply coating material to an object (not shown in the drawings).

The illustrated embodiment of the spray gun 1 according to the invention is the coating material to be applied to the object especially electrostatically charged or chargeable coating powder.

However, it is envisaged that a spray gun 1 constructed in accordance with the invention may also be used to apply coating materials other than electrostatically charged coating powder to an object. For example, the spray gun 1 can be used to apply liquid coating materials to an object.

The spray gun 1 , as shown schematically in the drawings, essentially has a handle part 2 and a gun barrel 3 connected to the handle part 2 .

As can be seen in particular from the exploded views, the manually grippable handle part 2 has a base body 4 which is connected to a base body 4 of the pistol barrel 3 . The base body 4 of the grip part 2 is preferably formed in one piece with the base body 4 of the pistol barrel 3, for example as a monolithic plastic injection molded part. In this way, a particularly one-piece base body 4 of the spray gun 1 is created.

The gun barrel 3 of the spray gun 1 has a first (front) area 3a extending up to a nozzle arrangement 6 and a rear second (rear) area 3b. Here it is provided that the grip part 2 is arranged between the front and rear area 3a, 3b, specifically preferably in an area in which the grip part 2 is arranged over the center of gravity of the entire pistol barrel 3. This promotes the well-being of the operator of the spray gun 1 during use of the spray gun 1, in particular over a relatively long period of time.

The base body 4 of the spray gun 1 is in particular formed in one piece from an electrically insulating (polymeric) material.

Although not shown in the drawings, an electrode arrangement can be accommodated or integrated in the gun barrel 3 of the spray gun 1 in order to electrostatically charge the coating material to be sprayed, if required. For this purpose, in particular the gun barrel 3 inside a corresponding voltage multiplication unit can be included, which is connected to the electrode arrangement. The voltage multiplication unit and the electrode assembly cooperate to generate an electric field for electrostatically charging the coating material to be sprayed onto an object.

The coating material to be sprayed, in particular coating powder entrained in an air stream, is fed to the spray gun 1 from a powder source not shown in the drawings. The flow of the coating powder entrained in the air is fed from a coating material supply line through an adapter 7 provided at the lower region of the handle part 2 into a coating material line running through the handle part 2 .

Connections 9a for compressed air and connections 9b for electrical energy are also provided at the lower end area of the handle part 2 .

In the embodiment of the spray gun 1 according to the invention shown in the drawings, the back of the main body of the spray gun 1 is covered by a rear shell 10 .

It is provided here that the rear shell 10 can be detachably and interchangeably attached to the rear of the base body of the spray gun 1, with the rear shell 10 being fixed to the base body 4 of the spray gun 1 preferably by a single screw 30 guided through the rear shell 10 in the attached state.

A further screw 31 can optionally be provided, which through the lower end area of the base body of the pistol barrel 3 suitably interacts with a screw receptacle provided inside the rear shell 10 .

The rear shell 10 essentially has a first area embodied as a grip 11 and a second area embodied as a cover 12, with the first area embodied as a grip 11 serving to cover the base body 4 of the gun barrel 3 of the spray gun 1, in particular on the rear. Designed as a cover shell 12 second region of Rear shell 10 is used to cover the rear of a rear area of the pistol barrel 3.

A connecting element 14 in the form of a hook-shaped area is also provided on the second area of the rear shell 10 . In its fully assembled state, the spray gun 1 can be releasably connected to a holder, for example, via this connecting element 14 .

According to the invention, it is provided in particular that the entire rear shell 10 together with the at least one connecting element 14 (hook-shaped area) is designed as a monolithic plastic component, in particular a plastic injection molded part.

As indicated in the drawings, the rear shell 10 can also have a transition area 13 which connects the first area designed as a grip shell 11 to the second area designed as a cover shell 12 . This transition area 13 is also monolithic (as part of the entire rear shell 10) and connected in one piece to the grip shell 11 and the cover shell 12.

The first area designed as a grip shell 11 is approximately U-shaped or V-shaped in cross section, at least in some areas, and has a rear wall and two side walls integrally formed thereon. In this case, it is provided in particular that the outer surfaces of the rear wall and the side walls formed thereon of the first area designed as a grip shell 11 have a configuration that is adapted to increase grip security.

In particular, in the exemplary embodiment shown in the drawings, a polygonal wave shape adapted to the hand of the operator of the spray gun 1, specifically adapted in an ergonomic manner, is provided to increase grip security.

The representation in FIG. 3 It can be seen in particular that in the embodiment shown in the drawings, a cable strain relief 15 is integrated in the rear wall of the first area of the rear shell 10 designed as a grip shell 11 .

With regard to the second region of the rear shell 10 designed as a covering shell 12, it is provided that this is approximately U-shaped in cross section, at least in regions, with a rear wall and two side walls integrally formed thereon. In addition, the second area configured as cover shell 12 has an upper wall that is at least partially or partially opposite the first area configured as handle shell 11 and is integrally formed on the rear wall and the side walls formed thereon of the second area configured as cover shell 12. The connecting element 14 is formed in one piece in the form of a hook-shaped element on this upper wall.

According to the isometric view, for example FIG. 3 it can be seen that in the exemplary embodiment in the rear wall of the second area designed as a covering shell 12 there is an opening 16 , which is set back in particular for an operating element 5 of the spray gun 1 . In particular, this opening 16 is designed to accommodate and embed the operating element 5 of the spray gun 1 in a recessed manner.

Furthermore, it can be seen from the drawings that at least one galvanically conductive grounding element 17 is integrated in the rear shell 10 and preferably in the material of a side wall of the second area designed as a cover shell 12 . The at least one grounding element 17 serves to ground a counter-electrode of the spray gun or to set it to a ground potential. For this purpose, in the assembled state of the spray gun 1, the grounding element 17 integrated in the rear shell 10 can be connected via a grounding conductor, such as a galvanically conductive connecting web, to a counter-electrode arranged in the vicinity of a charging electrode of the spray gun, in order to connect the counter-electrode to an electrical potential which is different from the electrical potential to which the charging electrode is connected. In this way, at least some of the free ions generated during the electrical charging of the coating powder can be absorbed via the counter-electrode and the grounding element 17 integrated in the rear shell.

Preferably, the grounding element 17 integrated in the rear shell is electrically conductively connected to grounding or a potential connection via an electrical line running in particular inside the handle 2 of the spray gun 1 .

On the front longitudinal edge of the side walls of the rear shell 10, a centering device 18 in the form of a centering tab is provided at least in some areas, via which an independent alignment of the position of the rear shell 10 relative to the rear of the base body of the spray gun 1 is made possible when the rear shell 10 is mounted on the rear of the base body.

In addition, in the embodiment shown in the drawings, at least one guide element 21 formed inside the rear shell 10 is provided in order to simplify a plug-in movement when mounting the rear shell 10 on the rear of the main body of the spray gun 1 .

The end faces 19 of the front longitudinal edge of the side walls of the rear shell 10 are preferably stepped in order to be able to form a type of labyrinth seal with a corresponding area on the back of the base body of the spray gun 1 .

Claims (15)

1. A spray gun (1), in particular powder spray gun (1), comprising a handle member (2) and a gun barrel (3) connected to the handle member (2), wherein a rear casing (10) is attached to the rear side of a base body (4) of the spray gun (1),
   a first region designed as a handle casing (11) and a second region designed as a cover casing (12) for the rear-side covering of a rear region of the gun barrel (3), wherein at least one connection element (14) is provided on the second region of the rear casing (10) for forming a detachable connection as needed to a component of at least partially complementary design thereto, wherein the entire rear casing (10) together with the at least one connection element (14) is formed as a monolithic plastic component, particularly a plastic injection-molded part, wherein the gun barrel (3) of the spray gun (1) comprises a front region (3a) extending to a nozzle assembly (6) as well as a rear-side rear region (3b), wherein the handle member (2) is arranged between the front and rear region (3a, 3b), and specifically in a region in which the handle member (2) is located beneath the center of mass of the gun barrel (3) as a whole.
2. The spray gun (1) according to claim 1,
   wherein the rear casing (10) comprises a transition region (13) connecting the first region designed as a handle casing (11) to the second region designed as a cover casing (12).
3. The spray gun (1) according to claim 1 or 2,
   wherein the first region designed as a handle casing (11) is at least in part of approximate U or V shape in cross section with a rear-side wall and two side walls integrally formed thereon.
4. The spray gun (1) according to claim 3,
   wherein the outer surfaces of the rear-side wall and the side walls formed thereon of the first region designed as handle casing (11) exhibit a configuration, in particular a surface configuration, adapted to increasing secure grip, and that particularly in the form of a multi-edged shaft adapted to the human hand.
5. The spray gun (1) according to claim 3 or 4,
   wherein at least one cable strain relief (15) is integrated into the rear-side wall of the first region designed as a handle casing (11).
6. The spray gun (1) according to one of claims 1 to 5,
   wherein the second region designed as a cover casing (12) is at least in part of approximate U shape in cross section with a rear-side wall and two side walls integrally formed thereon.
7. The spray gun (1) according to claim 6,
   wherein the second region designed as a cover casing (12) further comprises an upper wall integrally formed on the rear-side wall and the side walls formed thereon of the second region designed as a cover casing (12) with at least sections or parts thereof disposed opposite the first region designed as a handle casing (11).
8. The spray gun (1) according to claim 7,
   wherein the at least one connection element (14) is integrally formed on the upper wall and is preferably designed as a hook-shaped or eyeletshaped element.
9. The spray gun (1) according to one of claims 6 to 8,
   wherein at least one in particular recessed opening (16) for at least one control element and/or display element (5) of the spray gun (1) is provided in the rear-side wall of the second region designed as a cover casing (12), wherein the at least one opening (16) is designed to accommodate and/or embed the at least one control element and/or display element (5), particularly in a recessed manner.
10. The spray gun (1) according to one of claims 6 to 9,
    wherein at least one seating for a switch and preferably an integrally formed element which is movable relative to the rear casing (10) for actuating the switch is formed in the rear casing (10), and preferably in a side wall of the second region designed as a cover casing (11).
11. The spray gun (1) according to one of claims 6 to 10,
    wherein at least one galvanically conductive grounding element (17) is integrated into the rear casing (10) and preferably into the material of a side wall of the second region designed as a cover casing (12).
12. The spray gun (1) according to one of claims 1 to 11,
    wherein a centering device (18), particularly in the form of at least one centering tab or the like, is provided at least in part of the front longitudinal edge area of the side walls of the rear casing (10) for the positional aligning, in particular self-aligning, of the rear casing (10) relative to the rear side of the base body (4) of the spray gun (1) when the rear casing (10) is mounted on the rear side of the base body (4).
13. The spray gun (1) according to one of claims 1 to 12,
    wherein a graded region (19) is provided at least in part of the front longitudinal edge of the side walls of the rear casing (10), and in particular on the frontal area of the front longitudinal edge of the side walls of the rear casing (10), wherein the frontal areas are in particular formed complementary to a corresponding region on the rear side of the base body (4) of the spray gun (1).
14. The spray gun (1) according to one of claims 1 to 13,
    wherein at least one and preferably exactly one opening (20) is formed in the rear casing (10) for accommodating a screw (30) for the detachable fixing of the rear casing (10) to the base body (4) of the spray gun (1).
15. The spray gun (1) according to one of claims 1 to 14,
    wherein the entire rear casing (10) together with the at least one connection element (14) is formed as a monolithic component made of an anti-static plastic material, particularly polyamide 12.

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