EP3954468B1 - Spray gun - Google Patents

Description

The invention relates to a spray gun, a liquid guiding device and a set with a liquid guiding device.

A generic spray gun, a generic liquid guide device and a generic set are available from the EP 1 964 616 A1 known.

A similar spray gun, but where the liquid guide device is not pushed on but folded open, is shown by the US 2013/320110 A1

A thread is also understood to mean a bayonet lock. Within the scope of the invention, the base body and the liquid guide device are fastened to one another with a device such as a fastening nut.

The invention is based on the object of further developing such a spray gun and in particular a spray gun for paint.

This object is achieved with a generic spray gun having the features of patent claim 1.

The contact surfaces, which are arranged conically relative to one another, form a receptacle for a counterpart that can be inserted into the receptacle. As with a bottle cork, the component can be inserted into the counterpart with the contact surfaces to achieve a firm connection and a seal. The elevation with the passage and the contact surfaces arranged to the side of the passage can be formed on the liquid guide device, while the recess is formed in the base body. Alternatively, the recess can also be formed in the liquid guide device and accommodate an elevation formed in the base body.

A further aspect of the invention relates to a spray gun which has a fastening nut 4 and in which the base body has a thread 6 in order to fasten the liquid guide device 3 with the fastening nut 4 to the base body 2, wherein the thread 6 has a recess 7 and the liquid guide device 3 has at least one element 9 which protrudes radially from a central liquid guide tube 8 and which fits into the recess 7, so that after unscrewing the fastening nut 4, the liquid guide device 3 can be attached to the protruding Element 9 can be gripped in order to pull the liquid guide device 3 off the base body 2.

Instead of a fastening nut, a device such as an annular element can be used that holds the base body and the liquid guide device together and that can be arranged on the liquid guide device in such a way that the liquid guide device can be gripped by the protruding element in order to pull the liquid guide device off the base body. The device can also be plugged on or held in place in a locking manner, for example.

This makes it possible to initially manufacture the base body and the fastening nut from metal, while the liquid guide device is made from a plastic. The design according to the invention makes it possible to manufacture a spray gun in which the largest part of the liquid guide device is covered by metal parts. A liquid guide device made from plastic is thus protected externally by the metal parts and when the fastening nut is unscrewed, the liquid guide device can be easily grasped by the protruding elements in order to pull it off the base body.

A further aspect of the invention, which is essential to the invention even without the features described so far, relates to a generic spray gun which has a paint needle which is arranged in a channel of the liquid guide device, wherein a scraper is arranged between the channel and the paint needle.

When using the spray gun to spray varnishes, paints, adhesives, fillers or similar substances, spray guns are used in which a paint needle extends inside the liquid guide device. This paint needle therefore comes into contact with the liquid. When the liquid guide device or the needle is replaced, the needle remains dirty and must be cleaned, especially when changing colors.

It is therefore advantageous if a scraper is arranged between the channel and the paint needle. Such a scraper rests on the paint needle and, when the paint needle or the liquid guide device is pulled out, scrapes over the paint needle in such a way that the paint needle is freed of paint residues. This either makes cleaning the paint needle obsolete or at least makes it much easier. A simple embodiment provides that the scraper is inserted into the channel. For example, a rubber disk with a central hole can be used as a scraper, which wraps around the paint needle like a seal. Such a device inserted into the channel Disc, which can also be made of harder material and has, for example, a lip, is inexpensive to manufacture and can also be replaced if necessary.

Since it is advantageous to manufacture the liquid guide device as a disposable item, it is proposed to form the scraper in one piece with the liquid guide device. The scraper can be made of the same material as the liquid guide device. The shape of the scraper can ensure that it rests on the paint needle without restricting the mobility of the paint needle too much. The use of a two-component material for the manufacture of the liquid guide device makes it possible to manufacture a scraper in a material that is optimized for its function.

Another aspect of the invention, which can also be used independently of the features mentioned above, provides that an air distribution disc is screwed onto the base body, within which the liquid guide device extends. This makes it possible to use different air distribution discs with the same liquid guide device and to manufacture the air distribution disc from a different material than the liquid guide device. In particular, the air distribution disc can be made from metal, while the liquid guide device is made from plastic. Such an air distribution disc either has a thread with which it is screwed onto the base body, or it is screwed onto the base body with one or more screws that extend through holes in the air distribution disc.

Another aspect of the invention, which can also be used independently of the features mentioned above, provides that the base body has the air distribution disc. If the air distribution disc is manufactured as a single part, it can be placed on the base body and adapt various base bodies of spray guns to the paint supply device. On the other hand, a one-piece design of the air distribution disc with the base body of the spray gun has the advantage that no separate air distribution disc is required. For this purpose, the structure required as an air distribution disc is formed directly in the base body of the spray gun.

Another aspect of the spray gun, which can also be used independently of the features mentioned above, provides that it has an air cap, whereby the fastening nut pulls the air cap against the liquid guide device in such a way that the air cap can still be rotated when the fastening nut is screwed on. For this purpose, for example, a fit is provided which, on the one hand, allows the fastening nut to be tightened so tightly that the liquid guide device is securely attached to the base body and, on the other hand, a The air cap should only be clamped so tightly that it can still be rotated when the fastening nut is screwed on.

The air cap does not have to rest on an annular surface, but can also rest on just a segment of an annular surface to make it easier to rotate.

In particular with such a design, it is advantageous if the air cap has a contact surface with a locking element in order to lock in a certain position relative to the base body. The contact surface with the locking element can interact with a locking counterpart on the fastening nut, on a nozzle or on the liquid guide device or also on a movable pin.

Even independently of the features mentioned above, a design is advantageous in which the base body of a spray gun and a liquid guide device form an annular contact surface for a fastening nut, whereby the liquid guide device, which is not yet firmly screwed on, protrudes in a partial area of the contact surface compared to the rest of the contact surface. In practice, the liquid guide device is inserted into the base body and this leads to a part of the contact surface protruding compared to the rest of the contact surface. Only when the fastening nut is screwed on is this protruding part pushed into the plane of the rest of the contact surface and the liquid guide device is pressed against the base body so that a seal is created between the base body and the liquid guide device.

Cumulatively or alternatively, the liquid guide device can have a protruding element that engages in the thread of the fastening nut when the fastening nut is screwed on, so that the fastening nut presses the liquid guide device towards the base body when screwed on. The protruding element can have inclined contact surfaces that make it easier to engage with the thread, so that the protruding element is guided in a recess in the thread when the fastening nut is screwed on.

It is also advantageous if contact surfaces between the liquid guide device and the base body or a base body attachment are sealed and if passages are provided between these contact surfaces which enable an outwardly sealed passage from the base body of the spray gun to an air cap.

Regardless of the features mentioned above, it is particularly advantageous if, in order to attach a liquid guide device to the base body of a spray gun, the contact surfaces between the liquid guide device and the base body are arranged at an angle to the alignment of the liquid guide tube in such a way that a conical receptacle for the liquid guide device is created on the base body. The liquid guide device can then be pushed into the base body using the fastening nut, for example, whereby the inclined contact surfaces of the liquid guide device are pushed into the cone of the base body. This creates a good seal in a simple manner over a large surface area that also extends parallel to the liquid guide tube.

In order to be able to easily remove the liquid guide device from the base body again, another aspect, which is also independent of the features mentioned above, proposes arranging an axially displaceable pin in the base body. This pin can be used to exert pressure on the liquid guide device. When the pin is axially displaced, one end of the pin can press on the liquid guide device in order to remove the liquid guide device from the base body.

Such a pin can have a contact surface that is decentralized to its central axis for contact with the liquid guide device. This makes it possible to move the pin decentrally to the liquid guide tube of the liquid guide device and to press it onto the liquid guide device near the liquid guide tube. This minimizes the tilting of the liquid guide device when the pin is pressed onto a specific position of the liquid guide device when it is pushed out.

The object underlying the invention is also achieved with a liquid guide device that can be used for such a spray gun. This liquid guide device has a liquid inlet pipe that opens into a liquid guide pipe and is characterized by the features of patent claim 18.

The angle leads to conical contact surfaces, between which an air passage is provided and which, depending on the pressure, enable a particularly firm connection and thus also a special tightness.

The contact surfaces can be arranged in a U-shape or as a square. It is advantageous if they are arranged concentrically to the axis of the liquid guide tube and/or parallel to each other.

In this case, a raised area can be provided between the contact surfaces of the liquid guide device, in which the passage is provided, so that this raised area can be inserted into a corresponding recess in the base body. Alternatively, the recess can also be provided in the liquid guide device, into which a raised area of the base body is inserted.

According to a further aspect of the invention, the liquid guide device has a paint needle channel for a paint needle and, as a liquid guide tube, a paint channel for a spray agent, radially spaced therefrom. There is thus a wall between the paint needle channel and the liquid guide tube, which prevents the paint needle from becoming contaminated with liquid.

It is advantageous if the paint channel extends from the liquid inlet pipe (separated by a wall) from the paint needle channel to the outlet from the liquid guide device.

It is advantageous if a bushing is arranged in the liquid guide pipe in the direction of flow before the outlet. This bushing is preferably made of plastic. It can be screwed or glued into the liquid inlet pipe. The bushing is preferably held in the liquid guide pipe by means of a press fit.

To facilitate positioning of the bushing in the liquid guide tube, it is suggested that the bushing has a radial stop or a flange. This allows the bushing to be pushed into the liquid guide tube until the radial stop or the flange rests against the liquid guide tube.

It is advantageous if a scraper is arranged in the bushing. This scraper can work together with a paint needle to scrape liquid from the surface of the paint needle during a relative movement between the paint needle and the bushing.

This scraper can be formed by a perforated disc. Such a perforated disc either has a fine lip seal as a scraper or is made of a softer material such as rubber. This makes it possible to clean the paint needle with the perforated disc.

Such a perforated disc can be fixed in a recess of the bushing and preferably snap into place there, but it can also be manufactured by injection molding, so that a bushing is made of a two-component material, or a softer material is injected into a Recess is injected into the bushing so that an annular perforated disc is created which is one piece with the bushing and is therefore firmly connected to the bushing.

It is particularly advantageous if the scraper is formed by a flange that extends radially inwards from the bushing. This flange is preferably formed in one piece with the bushing. Even a small ring-shaped projection produced by injection molding that protrudes above the cylindrical inner surface of the bushing enables the bushing to rest in a ring on a paint needle, while the paint needle can be moved freely in the remaining area of the bushing.

A further development of the liquid guide device provides that a nozzle is arranged in the liquid guide tube in the flow direction after the mouth. This nozzle can be formed in one piece with the liquid guide tube or can be attached to the liquid guide tube.

It is advantageous if the nozzle is attached to the liquid guide tube with a press fit. Alternatively or cumulatively, the nozzle can also be attached to the liquid guide tube with a thread.

Depending on the design variant, it is advantageous if the nozzle has an air distribution disc. The air distribution disc can also be made in one piece with the liquid guide tube or attached to the liquid guide tube via a press fit. A screw connection is also possible.

In order to easily pull the liquid guide device out of the base body of a spray gun, it is proposed that a web extends radially outwards from the liquid feed pipe, at the end of which a gripping surface is arranged. At least two opposing gripping surfaces are advantageous, which can also be designed as pull tabs.

A special embodiment provides that pressure on a gripping surface leads to a deformation of the liquid guide device, via which the liquid guide device presses selectively against the base body of a spray gun in order to release the liquid guide device from the base body.

The liquid inlet pipe may have a radially outwardly extending flange with air holes. This radial flange with air holes may serve as an air distribution disc or only allow air to pass through in a flow parallel to the liquid inlet pipe.

It is advantageous if a web extends in an area of the outer surface of the radially outwardly extending flange, at the end of which a gripping surface is arranged. The liquid guide device can then be held, for example, by a gripping surface on the liquid guide tube and one on the outwardly extending flange in order to pull it out of the base body of a spray gun.

After the spraying process, the spray gun cup is usually unscrewed from the liquid guide device and emptied and cleaned or sealed hermetically to store the remaining paint. The liquid guide device is cleaned or thrown away and the paint needle on the base of the paint spray gun is cleaned. According to the invention, it is proposed that after the spraying process, the liquid guide device is removed from the base of the spray gun together with the spray gun cup and the two remaining openings are closed as the inlet and outlet of the liquid guide tube. For this purpose, it is proposed that the liquid guide device has an inlet and an outlet opposite one another and a closure device, with the closure device closing the inlet and the outlet. In order to be able to set up the spray gun cup with the liquid guide device pointing upwards, the air flow opening is closed on flow cups. The flow cup can then also be placed on its lid. This means that the spray gun cup is sealed hermetically for storage when the liquid guide device is screwed on.

While the cup, and in particular a gravity cup, can be closed with a simple stopper, two openings on the liquid-conducting device must be closed when the cup is closed with the liquid-conducting device. For this purpose, the closure device is provided with two lids, stoppers or screw caps. It is advantageous if the lids, stoppers or screw caps are identical so that different closure devices do not have to be stocked.

A particularly preferred embodiment makes it possible to close both openings of the liquid guide device with a closure means. For this purpose, it is proposed that the closure device has a mandrel that closes the inlet and outlet. This mandrel can be inserted into the liquid guide device like a paint needle and locking areas and/or fits ensure that the openings are sufficiently airtight. It should be noted that the mandrel will seal off areas that are not completely sealed when the paint dries. When the mandrel is removed, the openings are opened again so that the cup with the liquid guide device can be inserted into the spray gun body.

The paint needle or part of a paint needle can also be used as a mandrel. If the paint needle can be removed from the spray gun or the paint needle can be divided so that the front part of the paint needle can be separated from a rear part, it is possible for the mandrel to be part of a paint needle. The closure device and in particular the mandrel can preferably be made from a plastic material. The closure device can then be designed as a disposable component which, after spraying, serves together with the liquid guide device as an airtight seal for the paint outlet of the spray gun cup.

A suitable divisible paint needle is, for example, a paint needle such as the one in the EN 10 2007 053 855 A1 is described. Reference is made to this document in its entirety. As soon as axial displacement means of the paint needle can be connected to the paint needle, the paint needle or a part of the paint needle can be separated from the base body of the spray gun in order to use it as a closure device after spraying.

According to the invention, a method is thus provided in which a liquid guide device is part of the spray gun during spraying and is removed from the spray gun after spraying, preferably together with the cup, in order to serve as a closure or closable paint reservoir.

The statements regarding the closure device and its use are essential to the invention even without the features described above.

In order to make it easier for the user to select the correct nozzle for a liquid guide device, a set with a liquid guide device is proposed which has a liquid guide tube in which a nozzle with a bore is arranged. According to the invention, the set has various nozzles with different bore diameters, whereby nozzles with different bore diameters have different colors.

Alternatively, a set with several liquid guide devices is proposed, which have different nozzles with different bore diameters, whereby liquid guide devices with different nozzles have different colors. The user can This means that the user can select a specific liquid guide device with a certain bore diameter from a range of different types, with the colour immediately showing the bore diameter of the nozzle of the liquid guide device.

The features of claims 4, 5, 8, 9, 12, 13, 14, 1, 16, 18, 23, 25, 27, 31, 36, 40, 41, 43, 44 and 45 describe aspects of spray guns and liquid guiding devices which are essential to the invention, even independently of the features of the preceding claims.

Figur 1

eine perspektivische Ansicht einer Spritzpistole,

Figur 2

eine Explosionszeichnung der in Figur 1 gezeigten Spritzpistole,

Figur 3

eine perspektivische Ansicht einer Spritzpistole mit Luftverteilerscheibe,

Figur 4

eine Ansicht der Rückseite der Luftverteilerscheibe,

Figur 5

einen Schnitt durch die in Figur 3 gezeigte Spritzpistole,

Figur 6

eine Vorderansicht der in Figur 3 gezeigten Spritzpistole,

Figur 7

eine Explosionszeichnung einer Flüssigkeitsleiteinrichtung mit aufgeschraubter Düse,

Figur 8

eine Seitenansicht der in Figur 7 gezeigten Flüssigkeitsleiteinrichtung,

Figur 9

eine Vorderansicht der in Figur 7 gezeigten Flüssigkeitsleiteinrichtung,

Figur 10

einen Schnitt durch die in Figur 7 gezeigte Flüssigkeitsleiteinrichtung,

Figur 11

eine vergrößerte Ansicht des in Figur 10 gezeigten Details B,

Figur 12

eine vergrößerte Ansicht des in Figur 10 gezeigten Details C,

Figur 13

eine vergrößerte Ansicht des in Figur 12 gezeigten Details D,

Figur 14

eine vergrößerte Ansicht des in Figur 10 gezeigten Details E,

Figur 15

eine Düse für eine Presspassung,

Figur 16

einen Schnitt durch eine Flüssigkeitsleiteinrichtung mit einer Düse mit Presspassung,

Figur 17

eine vergrößerte Darstellung des in Figur 16 gezeigten Details B,

Figur 18

eine vergrößerte Darstellung des in Figur 16 gezeigten Details C,

Figur 19

eine vergrößerte Darstellung des in Figur 18 gezeigten Details D,

Figur 20

einen Schnitt durch eine Spritzpistole mit aufgeschraubter Befestigungsmutter,

Figur 21

einen Schnitt durch eine Spritzpistole mit abgeschraubter Befestigungsmutter,

Figur 22

eine vergrößerte Darstellung des in Figur 21 gezeigten Details G,

Figur 23

eine perspektivische Ansicht einer Spritzpistole mit abgeschraubter Befestigungsmutter,

Figur 24

eine vergrößerte Darstellung des in Figur 23 gezeigten Details C,

Figur 25

einen Teil eines Schnitts durch die in Figur 23 gezeigte Spritzpistole mit aufgeschraubter Befestigungsmutter,

Figur 26

eine vergrößerte Darstellung des in Figur 25 gezeigten Details B,

Figur 27

eine perspektivische Ansicht der in Figur 23 gezeigten Spritzpistole,

Figur 28

eine perspektivische Ansicht der Rückseite der Befestigungsmutter mit eingelegter Luftkappe,

Figur 29

eine perspektivische Ansicht der in Figur 23 gezeigten Spritzpistole mit Befestigungsmutter mit Luftkappe,

Figur 30

eine Draufsicht auf eine Spritzpistole mit Grundkörper, Luftverteilerscheibe und Flüssigkeitsleiteinrichtung,

Figur 31

einen Schnitt durch die in Figur 30 gezeigte Spritzpistole,

Figur 32

eine perspektivische Ansicht einer Flüssigkeitsleiteinrichtung mit integrierter Düse,

Figur 33

eine Seitenansicht der in Figur 32 gezeigten Flüssigkeitsleiteinrichtung,

Figur 34

einen Schnitt durch eine weitere Flüssigkeitsleiteinrichtung mit integrierter Düse,

Figur 35

eine perspektivische Ansicht der in Figur 34 gezeigten Flüssigkeitsleiteinrichtung,

Figur 36

einen Schnitt durch eine Flüssigkeitsleiteinrichtung mit Düse und Luftverteilerring,

Figur 37

eine perspektivische Ansicht der in Figur 36 gezeigten Flüssigkeitsleiteinrichtung,

Figur 38

eine perspektivische Ansicht einer Spritzpistole,

Figur 39

eine vergrößerte Ansicht des Details A in Figur 38,

Figur 40

ein Beispiel für eine Nut-Feder-Verbindung mit abgeschrägter Nut,

Figur 41

ein Beispiel für eine Nut-Feder-Verbindung mit gestufter Nut,

Figur 42

eine perspektivische Ansicht einer Spritzpistole

Figur 43

eine Vorderansicht der in Figur 42 gezeigten Spritzpistole,

Figur 44

eine perspektivische Ansicht einer Spritzpistole,

Figur 45

einen vergrößert dargestellten Schnitt im Bereich der Luftverteilerscheibe,

Figur 46

eine perspektivische Ansicht einer Spritzpistole mit gekapselter Luftführung,

Figur 47

eine weitere Ansicht der in Figur 46 gezeigten Spritzpistole,

Figur 48

eine Explosionsdarstellung einer Spritzpistole mit zur Farbnadel beabstandeter Spritzmittelführung,

Figur 49

die Befestigung der Luftverteilerscheibe im Grundkörper der Spritzpistole,

Figur 50

eine Rückansicht der n Figur 48 dargestellten Spritzpistole als Explosionsdarstellung,

Figur 51

einen Schnitt durch die in den Figuren 48 bis 50 gezeigte Spritzpistole,

Figur 52

eine Ansicht eines Spritzpistolenbechers mit aufgeschraubter Flüssigkeitsleiteinrichtung und Dorn,

Figur 53

eine Ansicht der in Figur 52 gezeigten Flüssigkeitsleiteinrichtung mit eingesetztem Dorn,

Figur 54

einen Schnitt durch die in Figur 52 gezeigte Flüssigkeitsleiteinrichtung mit eingesetztem Dorn,

Figur 55

eine vergrößerte Darstellung der in Figur 54 gezeigten Flüssigkeitsleiteinrichtung,

Figur 56

zwei Ansichten einer Flüssigkeitsleiteinrichtung mit Dorn,

Figur 57

einen Schnitt durch die in Figur 56 gezeigte Flüssigkeitsleiteinrichtung,

Figur 58

einen Schnitt durch die einen vorderen Bereich der die in der Figur 57 gezeigten Flüssigkeitsleiteinrichtung,

Figur 59

eine Draufsicht auf die Rückseite der in Figur 57 gezeigten Flüssigkeitsleiteinrichtung,

Figur 60

einen Schnitt durch eine Flüssigkeitsleiteinrichtung mit einer Farbnadelabdeckung,

Figur 61

einen Schnitt durch eine Spritzpistole mit Farbbecher,

Figur 62

ein Detail des vorderen Bereichs einer Spritzpistole im Schnitt,

Figur 63

einen Schnitt eines vorderen Bereichs einer Spritzpistole,

Figur 64

vergrößert das in Figur 63 gezeigte Detail,

Figur 65

eine perspektivische Ansicht von der Seite auf eine Farbleiteinrichtung,

Figur 66

eine perspektivische Ansicht der Rückseite der in Figur 65 gezeigten Farbleiteinrichtung und

Figur 67

einen Schnitt durch die in Figur 65 gezeigte Farbleiteinrichtung.

Examples of spray guns and liquid guide devices according to the invention are shown in the drawing and are described in more detail below. It shows

Figure 1

a perspective view of a spray gun,

Figure 2

an exploded view of the Figure 1 shown spray gun,

Figure 3

a perspective view of a spray gun with air distribution disc,

Figure 4

a view of the back of the air distribution disc,

Figure 5

a cross-section of the Figure 3 shown spray gun,

Figure 6

a front view of the Figure 3 shown spray gun,

Figure 7

an exploded view of a liquid guide device with a screwed-on nozzle,

Figure 8

a side view of the Figure 7 shown liquid guide device,

Figure 9

a front view of the Figure 7 shown liquid guide device,

Figure 10

a cross-section of the Figure 7 shown liquid guide device,

Figure 11

an enlarged view of the Figure 10 shown details B,

Figure 12

an enlarged view of the Figure 10 shown details C,

Figure 13

an enlarged view of the Figure 12 shown details D,

Figure 14

an enlarged view of the Figure 10 shown details E,

Figure 15

a nozzle for a press fit,

Figure 16

a section through a liquid guide device with a press-fit nozzle,

Figure 17

an enlarged view of the Figure 16 shown details B,

Figure 18

an enlarged view of the Figure 16 shown details C,

Figure 19

an enlarged view of the Figure 18 shown details D,

Figure 20

a cross-section of a spray gun with a screwed-on fastening nut,

Figure 21

a cross-section of a spray gun with the fastening nut unscrewed,

Figure 22

an enlarged view of the Figure 21 shown details G,

Figure 23

a perspective view of a spray gun with the fastening nut unscrewed,

Figure 24

an enlarged view of the Figure 23 shown details C,

Figure 25

a part of a section through the Figure 23 shown spray gun with screwed fastening nut,

Figure 26

an enlarged view of the Figure 25 shown details B,

Figure 27

a perspective view of the Figure 23 shown spray gun,

Figure 28

a perspective view of the back of the fastening nut with air cap inserted,

Figure 29

a perspective view of the Figure 23 shown spray gun with fastening nut with air cap,

Figure 30

a top view of a spray gun with base body, air distribution disc and liquid guide device,

Figure 31

a cross-section of the Figure 30 shown spray gun,

Figure 32

a perspective view of a liquid guide device with integrated nozzle,

Figure 33

a side view of the Figure 32 shown liquid guide device,

Figure 34

a section through another liquid guiding device with integrated nozzle,

Figure 35

a perspective view of the Figure 34 shown liquid guide device,

Figure 36

a section through a liquid guide device with nozzle and air distribution ring,

Figure 37

a perspective view of the Figure 36 shown liquid guide device,

Figure 38

a perspective view of a spray gun,

Figure 39

an enlarged view of detail A in Figure 38 ,

Figure 40

an example of a tongue and groove connection with a bevelled groove,

Figure 41

an example of a tongue-and-groove connection with stepped groove,

Figure 42

a perspective view of a spray gun

Figure 43

a front view of the Figure 42 shown spray gun,

Figure 44

a perspective view of a spray gun,

Figure 45

an enlarged section in the area of the air distribution disc,

Figure 46

a perspective view of a spray gun with encapsulated air duct,

Figure 47

another view of the Figure 46 shown spray gun,

Figure 48

an exploded view of a spray gun with spray guide spaced from the paint needle,

Figure 49

the fastening of the air distribution disc in the base body of the spray gun,

Figure 50

a rear view of the n Figure 48 illustrated spray gun as exploded view,

Figure 51

a cross-section of the Figures 48 to 50 shown spray gun,

Figure 52

a view of a spray gun cup with screwed-on fluid guide device and mandrel,

Figure 53

a view of the Figure 52 shown liquid guide device with inserted mandrel,

Figure 54

a cross-section of the Figure 52 shown liquid guide device with inserted mandrel,

Figure 55

an enlarged view of the Figure 54 shown liquid guide device,

Figure 56

two views of a liquid guide device with mandrel,

Figure 57

a cross-section of the Figure 56 shown liquid guide device,

Figure 58

a section through the front area of the Figure 57 shown liquid guide device,

Figure 59

a top view of the back of the Figure 57 shown liquid guide device,

Figure 60

a section through a liquid guide device with a paint needle cover,

Figure 61

a cross-section of a spray gun with paint cup,

Figure 62

a detail of the front area of a spray gun in section,

Figure 63

a section of a front section of a spray gun,

Figure 64

increases the Figure 63 shown detail,

Figure 65

a perspective view from the side of a color guide device,

Figure 66

a perspective view of the back of the Figure 65 shown color guide device and

Figure 67

a cross-section of the Figure 65 shown color guide device.

In the Figure 1 The spray gun 1 shown has a base body 2, a liquid guide device 3 and a fastening nut 4. A paint cup 5 can be attached to the spray gun 1. The liquid guide device 3 is attached to the base body 2 by screwing the fastening nut 4 onto a thread 6 of the base body 2. The thread 6 has a recess 7 and the liquid guide device 3 has an element 9 protruding from its central liquid guide pipe 8, which can be inserted into the recess 7. The liquid inlet pipe 10 of the liquid guide device 3 enters a recess 11 of the base body 2.

The paint cup 5 can be attached directly to the liquid inlet pipe 10 or it can be connected to the liquid guide device using an adapter. An adapter makes it possible to connect different paint guide devices to different paint cups. The paint cup 5 can be screwed on, plugged on or attached with a locking closure. With a locking closure, a click closure is suitable, which clicks into place audibly and/or tactilely to indicate to the user that the paint cup 5 is securely attached and preferably even locked. It is advantageous if a stabilizing sleeve surrounds the closure.

After unscrewing the fastening nut 4, the liquid guide device 3 can be grasped at the protruding element 9 in order to pull the liquid guide device 3 off the base body 2.

An air distribution disc 12 is screwed to the base body 2 by means of screws 13, 14. This air distribution disc 12 has a central recess 15 within which the liquid guide device 3 extends.

The liquid guide device 3 has an opening 16 at which the liquid feed pipe 10 opens into the liquid guide pipe 8. In the direction of flow in front of this opening 16 there is a bushing 17 with a flange 18 which is press-fitted into the liquid guide pipe 8. An annular rubber disk 19 is attached inside the bushing 17 as a wiper for the paint needle 20. This rubber ring is arranged approximately in the area of the flange 18 and forms a wiper for the paint needle 20 at the point where the needle 20 enters the bushing 17.

At the outlet of the needle 20 from the bushing 17, a radially inwardly extending flange 21 is provided on the inside of the bushing 17, which wipes the paint needle 20 at this point on the bushing 17. This flange 21 is manufactured from the material of the bushing by injection molding during the manufacture of the bushing.

In the direction of flow at the front end of the liquid guide device 3, a nozzle 22 with a thread 23 is attached in the liquid guide tube 8. In the Figures 15 to 19 In the alternative embodiment shown, a nozzle 24 is secured with a press fit 25 in the liquid guide tube 8. The nozzles 22 and 24 each have an air distribution disk 26 and 27, respectively.

Such a nozzle can be attached to the liquid guide tube with or without an air distribution disc as a press fit. The nozzle can be fitted into a recess in the liquid guide tube or the liquid guide tube is pushed into a recess in the nozzle. The fit is particularly stable if at least one of the two parts is not yet fully hardened when pushed together. The part then hardens after being pushed together and shrinks, which significantly increases the strength of the fit between the parts. The strength can also be increased even further if a small groove or undercut is provided between the parts in order to achieve a positive connection.

The nozzle or part of the nozzle can also be made of metal. This makes it possible to make the contact area between the paint needle tip and the nozzle out of metal in order to increase the stability of the nozzle.

A web 28 with a gripping surface 29 extends radially outward from the liquid guide tube 8. This gripping surface 29 is arranged in such a way that when the fastening nut 4 is screwed on, the gripping surface 29 is covered by the fastening nut 4. Opposite the gripping surface 29, a gripping surface 30 is attached to a web 31, the other end of which is located on a flange 32 extending radially outward from the liquid guide tube 8. This flange 32 is provided with holes 33 like an air distribution disk.

An air cap 34 with two color horns 35, 36 is arranged in the fastening nut 4, so that the air cap 34 is pressed against the liquid guide device 3 when the fastening nut 4 is screwed on. The air cap 34 rests against the liquid guide device 3 with its inclined contact surface 37 in such a way that the air cap 34 can still be rotated even when the fastening nut 4 is screwed on. A special fit on the contact surface 37 defines the force with which the air cap 34 can be rotated when the fastening nut 4 is screwed on.

When the spray gun 1 is assembled, the paint needle 20 extends in a channel 38. This channel 38 is formed by a bore 39 in the bushing 17, a widened space 40 in the area of the mouth 16 and a bore 41 in the nozzle 22 or 24. This channel ends at the nozzle tip 42, where the tip 43 of the paint needle 20 rests when the nozzle is closed and is positioned at a distance from the nozzle tip 42 when the nozzle is open.

This allows liquid such as paint to flow from the cup 5 through the liquid feed pipe 10 and the mouth 16 into the widened space 40 and from there through the bore 41 to the tip 42 of the nozzle 22. A flow of the liquid into the Bushing 17 is avoided by the flange 21, which fits tightly against the paint needle 20, but allows axial movement of the paint needle 20.

When the entire liquid guide device 3 is pulled out of the base body 2 of the spray gun 1, only a movement in the direction of the axial extension of the paint needle 20 is possible. The flange 21, which is in a ring shape on the paint needle 20, is pulled over the front end of the paint needle, whereby any liquid or paint adhering to the paint needle 20 is stripped off. The stripped paint needle area then reaches the perforated disk 19, where any paint still adhering to it is stripped off again.

In the embodiment, two different wipers 19 and 21 are arranged in the bushing 17. Of course, several identical or different wipers in different design variants can also be arranged within the bushing 17 in order to clean the paint needle as much as possible when the liquid guide device 3 is pulled out.

The air cap 34 with the paint horns 35 and 36 is inserted in the fastening nut 4 in a rotatable but captive manner. After screwing on the fastening nut 4, the paint horns 35, 36 should be arranged in a certain position (vertical or horizontal). For this purpose, locking elements 45, 46 are provided on the one hand on the air cap 34 and on the other hand on the nozzle 22 or the body 44 of the liquid guide device 3, which noticeably indicate one or more special positions when the air cap 34 is turned.

When the fastening nut 4 is screwed onto the thread 6 of the base body 2, the fastening nut 4 moves in the axial direction towards an annular surface 47. During this movement towards the surface 47, the fastening nut 4 touches a protruding area 49 of the liquid guide device 3 in a recessed partial area 48. This means that when the fastening nut 4 is screwed on, the liquid guide device 3 is pressed into the base body 2 of the spray gun 1.

In addition, the pressing of the liquid guiding device 3 when screwing on the fastening nut 4 can be pressed into the base body 2 of the spray gun 1 by a protruding element 50 (only shown schematically), in that the protruding element 50 engages in the thread 51 of the fastening nut 4.

The liquid guide device 3 should be inserted into a receptacle 52 in the base body 2 of the spray gun 1, centered along the orientation of the paint needle 20. For this purpose, the contact surfaces 53, 54 between the liquid guide device 3 and the base body 2 are slightly conical. In Figure 31 an angle 55, 56 of 1° is indicated in each case, which indicates the conical design. The radially extending surfaces 57 and 58 on the webs 28 and 31 are also slightly conical and interact with correspondingly conical contact surfaces in the base body 2 in order to optimally seal the entire system between the liquid guide device and the base body in a ring shape and to position the liquid guide device precisely when inserted into the base body.

When the liquid guide device 3 is firmly inserted into the base body 2 and tightened by the fastening nut 4, a secure, tight fit is created between the base body 2 and the liquid guide device 3. This means that when the fastening nut 4 is unscrewed from the base body 2, the liquid guide device 3 continues to sit securely in the base body 2 and must be pulled out of the base body 2 using the gripping surfaces 29 and 30.

Preferably, the fastening nut 4 is made of metal with an annular contact surface made of plastic. This plastic contact surface acts on the liquid guide device 3 when the fastening nut 4 is screwed on and slides along the liquid guide device 3. When the fastening nut 4 is tightened, this plastic contact surface acts as a seal between the liquid guide device 3 and the fastening nut 4.

A further seal can be achieved between the fastening nut 4 and the base body 2 of the spray gun by providing a seal on the surface where the ring-shaped side of the fastening nut facing the base body has a seal, which then rests against the base body when the fastening nut is fully screwed on. Such a seal can also be provided on the contact surface on the base body, so that the fastening nut 4 moves towards this seal when screwed on, in order to compress the seal slightly when screwed tight in order to achieve a seal.

This provides a sealed space between the base body 2 and the fastening nut 4, in which the spray agent guide device can be arranged. This space is preferably sealed even up to the contact surface between the paint needle 20 and the opening in the fastening nut that interacts with it.

The removal of the liquid guide device 3 from the base body 2 can be facilitated by a pin 59 which is guided in a bore 60 in the base body 2 and has a contact surface 61 which acts on a counter surface 62 on the body 44 of the liquid guide device 3. The contact surfaces 61 and 62 are in the Figure 22 shown embodiment are formed parallel to each other and in the present case are arranged at an angle 63 of 65° to the extension of the paint needle 20 in order to exert a pressure force 64 on the liquid guide device 3 with the pin 59.

A pressure force 64 acting decentrally in the direction of the central axis 65 of the pin 59 to align the paint needle can lead to the liquid guide device 3 becoming jammed within the base body 2. Therefore, a contact surface 66 decentralized to the central axis 65 of the pin 59 is provided at the front end of the pin 59 in order to specifically exert a force on the liquid guide device decentrally to the axis 65 of the pin 59. By means of such a pin 59, it is possible on the one hand to arrange the pin 59 decentrally to the paint needle 20 and on the other hand to let the force 64 act on the liquid guide device 3 at any point or in a defined area in order to press the liquid guide device 3 out of the base body 2 as effectively as possible.

The pin 59 has a circumferential groove 67 in which a snap ring 68 is arranged, which in turn interacts with a spring 69 in such a way that the pin 59 is pressed into a position in which it does not press against the liquid guide device 3. The end 70 of the pin 59 thus acts as a push button with which the liquid guide device 3 can be ejected.

In an alternative embodiment not shown, the snap ring and spring are arranged in such a way that when the spring is relieved, the pin 59 is positioned with its end 70 in the base body and barely or not at all protrudes from the base body at the opposite end. When the liquid guide device 3 is inserted, the pin 59 is then pushed backwards against the spring force so that its end 70 protrudes from the base body. This also makes it possible to press the liquid guide device 3 out of the base body 2 with the pin 59 after unscrewing the fastening nut 4.

The pin 59 can also be pulled backwards away from the liquid guide device 3 against the force of a spring 69, so that the pin 59, when released, is accelerated by the force of the spring 69 and moves quickly towards the liquid guide device 3. As a result, the pin 59 strikes the liquid guide device 3. It has been shown that that even a small blow from behind on the liquid guide device 3, for example with such a pin 59, is sufficient to loosen the liquid guide device 3 such that it detaches from the base body 2 of the spray gun 1.

The pin can also be pressed against a spring force into the base body 2 of the spray gun 1 when the liquid guide device 3 is inserted. When the tension built up as a result is later released, the pin strikes the liquid guide device 3 and can thereby detach the liquid guide device 3 from the base body 2 of the spray gun 1.

Alternatively or cumulatively, the liquid guide device 3 can also be detached from the base body 2 of the spray gun 1 by the paint needle 20. For this purpose, a stop 108 is provided on the paint needle 20, which is arranged in such a way that it can act on the liquid guide device 3 (see Figure 42 ). The paint needle 20 can, for example, strike the rubber disk 17, the sleeve 19 on the rear side of the liquid guide device 3 or the nozzle 22 in the front area in order to detach the liquid guide device 3 from the base body 2 of the spray gun 1.

For this purpose, the base body 2 can have a trigger (not shown) which moves the paint needle in the usual way. In order to trigger a strike with the paint needle 20 against the liquid guide device 3, the trigger can be brought into a position in which the paint needle 20 presses against the liquid guide device 3. Preferably, a paint needle 20 pre-tensioned with a spring is triggered via the trigger so that the paint needle 20 strikes the liquid guide device 3, moved by the spring.

The pin 59 and the gripping surfaces 29, 30 thus represent alternatively or cumulatively usable means which make it possible to remove the liquid guiding device 3 from the base body 2.

A blow or pressure on the liquid guide device 3 can act on a weakened area of the liquid guide device 3 in such a way that it is destroyed by the blow. This means that the liquid guide device 3, when it is detached from the base body 2 of the spray gun 1, is changed in such a way that it cannot be used a second time. The liquid guide device 3 thus becomes a genuine disposable item that is only used once in practice because of its predetermined breaking point. This means that after each removal of the liquid guide device 3, only a new liquid guide device is required. 3 can be used and thus a clean liquid guide device 3 is always available.

In terms of construction, this is solved, for example, by the paint needle 20 or the pin 59 striking a surface which is deformed or broken off in such a way that the spray gun is subsequently no longer sealed.

The liquid guide device 3, the sleeve 17, the nozzles 22 and 24 and the air distributors 12, 32 and 27 can be manufactured as individual parts, preferably from plastic, using the injection molding process and attached to one another. However, as many of these parts of the liquid guide device 3 as possible are preferably manufactured in one piece, preferably using the injection molding process. The Figures 32 to 35 show how the body 44 of the liquid guide device 3 can be manufactured in one piece with a nozzle 71. The Figures 36 and 37 show that such a nozzle can also have an air distribution disk 72. This enables the most cost-effective production of a liquid guide device 3 as a plastic injection molded part from a single-component or multi-component material.

A secure seal must be ensured at the transition from the base body of the spray gun to the air distribution disc and from the air distribution disc to the spray agent guide device and also directly from the base body to the spray agent guide device. This seal can be achieved by simply pressing the spray agent guide device onto an air distribution disc or the base body of a spray gun, as the spray agent guide device is made of a softer material and can be made softer in the transition area by shaping it, for example by providing a fine lip. Further types of connection with tongue and groove are shown below, where the groove can also be arranged at the point where the tongue is drawn, provided that the tongue is also provided at the opposite point.

The Figure 38 shows the detail of the radially protruding element 80, which has an oblique fit or even a tongue and groove connection 81 in the area of its frontal contact in order to ensure a seal. Details of the connection between an air distribution disc 82, 83 and a spray agent guide device 84, 85 are shown in the Figures 40 and 41 . The Figure 40 a sealing ring with bevelled cone 86 and bevelled spring 87 and the Figure 41 a sealing ring with a stepped spring 88, which engages in a stepped groove 89. The design of the groove and spring can, as in Figure 40 shown also help to center the parts in a simple way.

At the Figure 42 In the spray gun shown, the lower pull tab has been eliminated. This makes sealing easier in this area. Only a small web 90 remains, the underside 91 of which is designed in such a way that the web 90 tapers towards the spray gun in order to center the spray agent guide device 92 when it is inserted into the base body 93. This web 90 can also be dispensed with in order to facilitate an annular seal. Figure 43 shows such a seal running through the lower area 94, which is only interrupted at the upper side 95, since this is where the spray agent inlet 97 is pushed into the corresponding receptacle 96 of the spray gun 98.

At shot 96 in the Figures 43 and 44 a shoulder 106 is indicated as a circumferential line, which is provided on the inside of the holder 96 on the spray gun. This shoulder 106 corresponds to a shoulder 107 on the spray agent guide device 92. This shoulder can serve as a contact surface for a spray agent cup (not shown). It is advantageous if the shoulder 106 is designed at least in part as a protruding element that interacts with a corresponding recess on the spray gun in a form-fitting manner. The protruding element can, for example, be a circumferential elevation that interacts with a corresponding groove in the spray gun. However, other elements such as a pin and a hole can also act as a form-fitting connection. Accordingly, the element can also protrude on the spray gun, while a corresponding recess is provided on the spray agent guide device.

A positive or, if necessary, a force-fitting connection between the spray gun and the spray agent guide device ensures that the liquid guide device is held in particular against tension or pressure in the axial direction of the spray agent inlet 97. This connection can hold the spray agent guide device at the spray agent inlet 97 in such a way that forces acting from a paint cup on the spray agent guide device are already intercepted in the area of the spray agent inlet 97.

The Figure 44 shows a spray gun 100 with a base body 101 into which an air distribution disc 102 is inserted. In order to seal the air distribution disc 102 against the base body 101, a groove 103 is provided in the base body 101, into which a circumferential web 104 of the air distribution disc 102 engages. When the spray agent guide device 105 is pushed towards the base body 101, the air distribution disc 102 is pressed against the base body 101 and the web 104 is pushed into the groove 103.

In practice, nozzles 71 with bores 73 with different bore diameters 74 are required. It is therefore proposed to produce spray guide devices 3 with different bore diameters 74 and, in order to distinguish them, to colour spray guide devices with different bore diameters 74 differently or to produce them from materials of different colours, such as plastics of different colours in particular. The spray guide devices can be produced in the same colour and only have nozzles in different colours. These nozzles can either be permanently connected to the body of the spray guide device via a press fit or they can be inserted into the body in an interchangeable manner using a thread.

Alternatively, a set can be produced with a liquid guide device and several different nozzles 22 that fit into the liquid guide pipe 8 of the liquid guide device 3 and have different bore diameters and possibly also different air distribution disks 72. In this case, it is advantageous if the various nozzles 22 are made in different colors or from different colored plastics. The nozzles 22 can also be made of metal and screwed into a body 44 of a liquid guide device 3 or fastened there in some other way. If the nozzle is permanently connected to the body of the spray guide device, various spray guide devices that have the same body but different nozzles in a color that matches the nozzle can be offered as a set. The body of the spray guide device is preferably made black and the nozzles have different colors.

In the Figure 46 The spray gun 110 shown has a base body 111, a liquid guide device 112 and an air cap 113. The liquid guide device 112 has an air distribution disc 114 with a cover 115 in which an opening 116 is provided for a paint needle 117. Below this there is an air opening 118 for the air supplied via the base body 111 to the inner air chamber for conveying the liquid and an air opening 119 as an inlet for the air supplied from the base body 111 to the outer air chamber for forming the spray jet.

This creates an encapsulated liquid guide device 112, which has two inlets 118 and 119 for the air supplied via the base body 111 of the spray gun and an inlet for passing through the paint needle 117. The sealing of the air supplied via the base body 111 thus takes place at the air openings 118 and 119, which in the embodiment are designed as small pipe pieces that fit into corresponding openings in the base body of the The air cap 113 is placed over the liquid guide device 112 and screwed onto the base body 111 in order to hold the liquid guide device 112 firmly onto the base body 111.

The Figures 48 to 51 show a variant of a spray gun 120 in which an air distribution disc 121 is inserted into the base body 122 of the spray gun 120 and is fastened there by means of screws 123 or by locking. The air distribution disc 123 thus becomes part of the base body 122 and is no longer part of the liquid guide device 124 as in the previously shown embodiments.

The air distribution disc 121 has annular sealing webs 125, 126 and 127, which interact with a corresponding structure such as a groove 128, 129, 130 on the liquid guide device 124 to delimit air channels 132, 133. The liquid guide device 124 has a cover 131 for this purpose, which together with the air distribution disc 121 forms and seals the air channels 132 and 133. The webs 125 to 127 can be arranged either on the air distribution disc 121 or on the cover 131. It is advantageous if webs made of a harder material such as aluminum or hard plastic interact with grooves made of a softer material to ensure good sealing. The webs are preferably arranged on the air distribution disc 121, while the grooves are provided on the cover 131. The seal between a web and a corresponding counter-structure can be improved by a sealing material that is provided in the two-component injection molding on the cover 131 and/or on the air distribution disk 121. It is advantageous if sufficient sealing is achieved solely by the shape of the web and groove.

In the Figure 48 In the embodiment shown, the cover 131 has three grooves 128, 129 and 130, between which two ring-shaped surfaces with air holes are formed, which are raised relative to the base surface of the grooves and are inserted between the ring-shaped webs 125 to 127 in such a way that they seal like a plug. For this purpose, a conicity can be provided between the contact surfaces of the groove and web, which facilitates insertion and ensures a secure seal when the cover 131 is pressed onto the air distribution disk 121.

The spray medium flows at the spray medium inlet 134 into the liquid guide device 124. From there, the spray medium enters a narrowed channel 135, in which the spray medium is guided in the direction of the paint needle 136. A wall 137 prevents the spray medium from the channel 135 arranged at an acute angle to the paint needle 136 into the paint needle channel 138. From the channel 135, the spray medium enters a paint channel 139 running parallel to the paint needle 136, which is also separated from the paint needle channel by the wall 137.

Until now, it was usual to let the spray flow in a straight line from the spray inlet 134 to the paint needle so that as few surfaces of the liquid guide device as possible are wetted by the spray and so the path of the spray from the spray inlet to the paint needle is kept as short as possible. This means that the spray travels in a longer paint channel from the base body of the spray gun along the paint needle to the nozzle and wets the paint needle and the channel of the liquid guide device in this area. In another known embodiment, the spray inlet is close to the nozzle so that the spray only wets the liquid guide device and the paint needle in the area of a shorter paint channel. However, this means that the center of gravity of the spray gun shifts towards the nozzle.

In the Figures 48 to 51 In the embodiment shown, the spray inlet 134 is located in an area surrounded by the base body 122 of the spray gun 120. The spray 150 flowing from the spray inlet on a straight line into the liquid guide device 124 and from there in the direction of the paint needle 136 cannot, however, reach the paint needle on this line but is diverted into a paint channel 139 running parallel to the paint needle, in which it reaches the paint nozzle 141 parallel to the paint needle through a wall 137 at a distance from the paint needle.

This means that the spray medium is guided within the base body 122 of the spray gun 120, but the paint needle only comes into contact with the spray medium to such an extent that the paint needle can be cleaned without having to be removed.

Compared to the Figure 2 The embodiment shown in the Figures 48 to 51 In the embodiment shown, no beech 17 is necessary, since this area can be injection-molded in one piece with the rest of the liquid guide device.

The liquid thus flows in the liquid guide device 124 through the wall 137, separated from the paint needle 136, to the liquid outlet 140, where the liquid exits the liquid guide device 124 and enters the spray nozzle 141.

At this point, the liquid flows from the paint channel 139, which is radially removed from the paint needle 136, in a keyhole-shaped area to the paint needle 139 and from there concentrically around the paint needle 139 into the nozzle 142. This area can be provided as a keyhole-shaped recess in the liquid guide device 124 and interact with a keyhole-shaped web 142 on the nozzle 141, so that the liquid is transferred from the liquid guide device 124 into the nozzle 141 in a sealed channel.

Radially outside the nozzle 141, conveying air is fed to the liquid in an inner air chamber, which generates a spray jet via the Venturi principle, and in an outer air chamber, air for forming the spray jet is fed from the liquid guide device 124 into the air cap 143, from where it reaches the paint horns 144 and 145.

In order to prevent the air for forming the spray jet from escaping from the outer air chamber and thus from the spray gun, a sealing surface 146 is provided on the outer circumference of the liquid guide device 124, which interacts with a sealing surface 147 arranged in the air cap 143. For this purpose, for example, a ring seal can be provided in the air cap 143. However, a seal can also be provided on the liquid guide device, which interacts with the air cap 143.

The paint needle 136 therefore only comes into contact with the spray medium 150 after it has exited the paint needle channel 130. This means that in practice only the front end of the paint needle 136 comes into contact with the spray medium, which significantly reduces the area of the paint needle that needs to be cleaned. In order to also make cleaning this area of the tip 148 of the paint needle 136 easier, an annular wiper 149 is provided at the exit of the paint needle 136 from the liquid guide device 124, which, when the liquid guide device 124 is pulled off the paint needle 136, wipes over the front end 148 of the paint needle 136 in order to clean the paint needle.

The Figure 52 shows the liquid guide device with an inlet 151 and an outlet 152 as well as a connection 153 to a paint cup 5. Between the inlet 151 and the outlet 152 is the liquid guide tube 8, at least a part of which is wetted with paint or liquid during spraying. Since the connection to the paint cup 5 is hermetically sealed, in this case as a screw cap, the paint cup is hermetically sealed when the inlet 151 and the outlet 152 are hermetically sealed. The closure device 154 serves this purpose, which in this case is designed as a mandrel 155 with a handle 156. The mandrel 154 is designed so long that it not only covers the inlet 151 but can also close the outlet 152 if it is arranged in the color channel 8.

The paint cup is designed as a flow cup 5 with an air afterflow opening 157, which in the present case is arranged in a lid 158 of the cup 5 and can be opened during the spraying process to allow air to flow in, while it is closed when the spray agent is stored.

The interaction of a mandrel 160 with a liquid guide device 161 shows the Figure 56 . In the direction of the supplied air and in the direction of the supplied liquid, which is usually a paint, a varnish or a filler, the mandrel 160 is inserted into the liquid guide device 161 until a stop 162 is reached. In order to hold the mandrel firmly, a blind hole 163 is provided, into which a reduced-diameter area 164 of the mandrel fits.

The mandrel 160 has a structured handle 165 and a nozzle 166 is provided on the liquid guide device 161 opposite this handle 165. This nozzle 166 is connected to the liquid guide device 161 via a fitting 167.

In order for the liquid guide device to cooperate in a sealing manner with an air distribution ring 121, slightly conical regions 168 with 10° and a notch 169 are provided on its rear side, with which the liquid guide device can engage like a plug in recesses in an air distribution ring 121.

When spraying with the liquid guide device, paint comes into contact with the paint needle inside the liquid guide device. In order to make this area as small as possible, a paint needle cover 170 is provided as part of the liquid guide device, which extends into the liquid area 171 as a conical tip tapering towards the nozzle 172. This tip acts as a paint needle cover and covers part of the paint needle that runs through the liquid area, so that only a particularly small area of the paint needle (not shown) comes into contact with the liquid. This means that after the liquid guide device 173 has been removed from the spray gun base, the paint needle is only wetted with liquid as little as possible and this area is easily accessible from the outside for cleaning.

The transition between the spray agent guide device, the spray gun body and the paint cup is designed in such a way that a screwed or attached paint cup can be supported directly on the spray gun body. A force between the paint cup and the spray agent guide device is thus minimized by the outlet of the paint cup having a contact surface which, when the paint cup is attached, rests against a contact surface on the spray gun body. This also means that the spray agent guide device is enveloped and stabilized by the spray gun body at the transition to the paint cup. If the spray agent guide device and the paint cup are made of plastic and the spray gun body is made of metal, then the metal area of the spray gun body supports and protects the spray agent guide device.

It is advantageous if the spray agent guide device can only be pushed onto the needle so far that it does not yet fully rest against the spray gun base body. The tip of the needle acts as a stop and prevents the spray agent guide device from being pushed further towards the spray gun base body. Only when the needle is pulled back using the handle on the spray gun base body does the spray agent guide device slide into its position on the contact surface on the spray gun base body. The paint agent guide device can also be pressed against the paint needle using the fastening nut, for example, so that the paint needle is pressed into the base body of the spray gun and the spray agent guide device slides into its position on the contact surface on the spray gun base body. The handle on the spray gun base body is then also pushed back slightly.

The contact surface between the paint needle and the spray guide device is particularly important. If the paint needle has a cylindrical section in the area in which it can be arranged in the spray guide device, then the paint needle can be retracted within the spray guide device so that the passage to the nozzle is opened without the conical tip of the paint needle being pulled into the spray guide device. This means that only a cylindrical section of the paint needle moves within the spray guide device, thus preventing spray from being drawn into the spray guide device between the paint needle and the paint guide device at the front area of the paint needle and wetting the inner surface of the spray guide device with spray.

A scraper can also be provided in the front area of the contact surface between the spray agent guide device and the paint needle. For this purpose, a ring-shaped flange protruding inwards is formed on the spray agent guide device, which rests against the paint needle. A circumferential groove can also be provided in the contact area to prevent paint from being scraped off. and to prevent spray agent adhering to the paint needle from entering the spray agent guide device.

The space in which the spray medium flows from the paint cup to the nozzle can be increased by designing the front area of the spray medium guide device, which extends around the paint needle, to be cylindrical on the inside and tapered towards the nozzle on the outside.

The Figure 61 shows how the paint cup 180 rests against the base body 182 of the spray gun 183 with a circumferential contact surface 181. A conical area 190 on the outside of the spray agent guide device 191 shows Figure 62 This increases the passage 192 for spraying agent. A scraper 200 on the system between the spraying agent guide device 201 and the paint needle 202 shows the Figure 63 with the detail 64. A space 203 between the spray agent guide device 201 and the paint needle 202 extends to the scraper 200, which cooperates with a small groove 204.

An essential aspect of the invention is the airtight seal between the color guide device and the base body or an air distribution disc attached to the base body. For this purpose, a raised area is provided on the color guide device in which at least one passage is arranged. This raised area fits like a cork into a recess on the base body or a base body attachment. When the color guide device and the base body or base body attachment are pushed onto one another, the raised area slides into the recess in such a way that a seal is created between the parts. The raised area thus acts as a seal with a passage. It is understandable that the raised area can also be arranged on the base body or a base body attachment if a corresponding recess is provided in the color guide device. It is advantageous if at least one of the parts is made of such an elastic material that sealing is facilitated. For example, the color guide device can be made of a plastic and the base body or the base body attachment can be made of metal or a harder plastic than the plastic of the color guide device. The elevation and depression can each be conical so that the elevation can slide far enough into the depression to create a good seal. However, there can also be just one conical insertion area that transitions into a cylindrical area so that the seal is at least also created on a cylindrical contact surface.

An example is shown in the Figures 58 and 59 as well as in the Figures 65 to 67 shown. An almost ring-shaped elevation 205 with passages 206 to 216 concentrically encloses another almost ring-shaped elevation 217 with passages 218 to 224. The base body attachment 226 provided on the spray gun 225 has corresponding almost ring-shaped receptacles 227 and 228. Slightly conical contact surfaces 229 to 232 enable the elevations 205 and 217 to slide into the receptacles 227 and 228 and for the contact surfaces 229 to 232 to seal, while the passages 206 to 216 and 218 to 224 enable an outwardly sealed passage from the base body of the spray gun 225 to the air cap 233. Depending on the design variant, only one elevation with a corresponding receptacle and individual shape can be provided.

The paint guide device 237 has a shoulder 235 in the area of the liquid feed pipe 234 that rests on the base body of the spray gun. Another shoulder 236 serves as a contact surface for a screwed-on paint cup. These contact surfaces 235 and 236 are arranged at an acute angle to one another, so that the paint guide device 237 can be easily pushed onto the base body of the spray gun 225, while a paint cup can be screwed onto the slightly angled liquid feed pipe. The paint cup is thus held almost to the paint guide device by screwing it on, and the paint guide device, when pushed onto the base body of the paint spray gun, rests on the base body of the paint spray gun on the contact surface formed between the paint guide device and the base body.

Claims (12)

1. A spray gun (225) with a basic body (2), a paint needle (20), a liquid conveying device (3) which has a liquid supply pipe (234) which opens at an opening (16) into a liquid conveying pipe (8), and with contact surfaces between the liquid conveying device (233) and the basic body (2) or a basic body component (226), characterized in that the liquid conveying device (233), in the region of the liquid supply pipe (234), has a shoulder as a contact surface (235) which rests against the basic body of the spray gun, and a further shoulder (236) which serves as a contact surface for a screwed-on paint cup, wherein these contact surfaces (235 and 236) are arranged at an acute angle to one another so that the paint conveying device (233) can be easily pushed onto the basic body (2) of the spray gun (225) in the direction of the paint needle (20), and when it has been pushed onto the basic body, is supported on the contact surface formed between the paint conveying device and the basic body, while a paint cup can be screwed onto the liquid supply pipe (234) arranged at a slight angle to the liquid conveying pipe (8).
2. A spray gun (1) with a basic body (2), a liquid conveying device (3) and with contact surfaces between the liquid conveying device (237) and the basic body (2) or a basic body component (226), characterized in that the basic body has a liquid inlet (97) with a receptacle (96) on which a shoulder (106) is provided and a shoulder (107) is provided on the spray medium conveying device (92), or an element projects on the basic body while a corresponding recess is provided on the spray gun conveying device.
3. The spray gun according to claim 2, characterized in that the shoulder (106) is designed, at least in some areas, as a projecting element which positively interacts with a corresponding recess on the spray gun.
4. The spray gun according to any one of claims 2 or 3, characterized in that the projecting element is a circumferential elevation which interacts with a corresponding groove in the basic body of the spray gun.
5. The spray gun according to any one of claims 2 to 4, characterized in that the projecting element is a pin which interacts with a hole as a positive connection.
6. The spray gun according to any one of claims 2 to 5, characterized in that the shoulder (107) serves as a contact surface for a spray medium cup.
7. The spray gun according to any one of claims 2 to 6, characterized in that a positive or also a nonpositive connection between the basic body of the spray gun and the liquid conveying device also holds the liquid conveying device against tension or compression in the axial direction of the spray medium inlet (97).
8. The spray gun according to any one of the preceding claims, characterized in that two contact surfaces (229 to 232) are arranged conically to one another and in that at least one passage (206 to 216 and 218 to 224) is arranged between these contact surfaces (229, 230 and 231, 232, respectively).
9. The spray gun according to any one of the preceding claims, characterized in that it has a fastening nut (4) and the basic body has a thread (6) for fastening the liquid conveying device (3) to the basic body (2) by means of the fastening nut (4), wherein the thread (6) has a recess (7) and the liquid conveying device (3) has at least one element (9) which projects radially from a central liquid conveying pipe (8) and which fits into the recess (7), so that after unscrewing the fastening nut (4), the liquid conveying device (3) can be gripped on the projecting element (9) in order to pull the liquid conveying device (3) off the basic body (2).
10. The spray gun according to any one of claims 1 to 9, characterized in that it has a paint needle (20) which is arranged in a channel (38) of the liquid conveying device (3), and a stripper is arranged between the channel (38) and the paint needle (20), which stripper is formed integrally with the liquid conveying device (3).
11. The spray gun according to any one of the preceding claims, characterized in that an air distributor disk (12) is screwed onto the basic body (2), within which air distributor disk the liquid conveying device (3) extends.
12. The spray gun according to any one of the preceding claims, characterized in that it has an air cap (34), wherein the fastening nut (4) pulls the air cap (34) against the liquid conveying device (3) in such a manner that the air cap (34) can still be rotated when the fastening nut (4) is screwed on, wherein the air cap (34) has a contact surface (37) with a latching element (45, 46) in order to latch in a specific position relative to the basic body (2).

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