Connection device for a spray gun, spray gun and method for operating a spray gun

Description

[0001] The invention relates to a connection device for a spray gun for atomizing a flowable material using compressed air, wherein the connection device has a first connection for connecting an air line and a second connection for connecting a material line, wherein the connection device is designed as a rotary joint, such that the first connection and the second connection are rotatable relative to the spray gun about a common axis of rotation, wherein the connection device comprises a fixed part that is stationary relative to the spray gun and a rotating part that is rotatably connected to the fixed part, wherein the rotating part has the first connection and the second connection, and wherein the fixed part comprises a nozzle element that can be fixedly connected to the spray gun.The invention further relates to a spray gun for atomizing a flowable material using compressed air, a method for operating a spray gun designed for atomizing a flowable material using compressed air, and the use of a connection device for a spray gun designed for atomizing a flowable material using compressed air.

[0002] A spray gun of the type described above is well known in the art and is regularly used for painting, whereby a flowable material, for example, paint or coating material, can be dispensed onto an object to be painted using compressed air. Typically, the handle of the spray gun has a first connection at one end, to which an air line from a compressed air source is connected, and the shaft of the spray gun, in the area of ​​a nozzle assembly, has a second connection to which a material line from a material source is connected. Thus, the spray gun has two connection points, which adversely restricts the operator's freedom of movement during operation.

[0003] The present invention is therefore based on the objective of proposing a connection device for a spray gun, a spray gun, a method for operating a spray gun and a use of a connection device for a spray gun which enables simplified operation of the spray gun.

[0004] DE 38 34 983 A1 discloses a connection device according to the preamble of claim 1.

[0005] FR 1 204 772 A discloses a swivel joint comprising a fixed central body surrounded by a housing connected to the central body by means of ball bearings. The swivel joint serves to distribute three different liquids. For this purpose, the swivel joint includes an axial channel that can be connected via a thread to a conduit or fixed pipe through which one of the liquids to be distributed can flow. The channel opens into a chamber in which an outlet is mounted. Furthermore, two additional axial channels are provided, each opening into an annular chamber. Openings are also provided in the housing that can receive a threaded end of an end piece attached to a pipe distributor. The housing can rotate at any angle up to 360°. The pipes leading to the outlet or the openings can therefore be oriented in any desired direction.

[0006] This problem is solved by a connection device having the features of claim 1, a spray gun having the features of claim 13, a method having the features of claim 14 and a use having the features of claim 15.

[0007] The connection device according to the invention for a spray gun for atomizing a flowable material using compressed air has a first connection for connecting an air line and a second connection for connecting a material line, wherein the connection device is designed as a rotary joint, such that the first connection and the second connection are rotatable relative to the spray gun about a common axis of rotation, wherein the connection device comprises a fixed part that is stationary relative to the spray gun and a rotating part rotatably connected to the fixed part, wherein the rotating part has the first connection and the second connection, wherein the fixed part comprises a nozzle element that can be fixedly connected to the spray gun, wherein the fixed part comprises an axle element that is fixedly connected to the nozzle element and on which the rotating part is rotatably mounted, and wherein the axle element has a material channel.

[0008] Accordingly, the connection device allows both the air line, which can be connected to a compressed air source at one end, and the material line, which can be connected to a material line at one end, to be connected to essentially a single connection point on the spray gun. Furthermore, the connection device is designed as a swivel joint, such that the first connection and the second connection, which is separate from the first, are rotatable about a common axis of rotation relative to the spray gun when the connection device is mounted on the spray gun. During operation of the spray gun, the air line connected to the spray gun via the connection device or the first connection can be connected together with the material line, which is also connected via the connection device or the second connection.The material line connected to the second port on the spray gun can be rotated around the common axis of rotation, especially when the spray gun is rotated by an operator, thereby increasing the operator's freedom of movement and simplifying the operation of the spray gun.

[0009] Advantageously, the connection device can be designed for mounting on the handle of the spray gun. Preferably, the connection device can then be attached to the end of the handle. The axis of rotation can run parallel to a longitudinal axis of the handle.

[0010] According to the invention, the connection device comprises a fixed part which, when the connection device is arranged on the spray gun, is stationary relative to the spray gun, and a rotating part which is rotatably connected to the fixed part, wherein the rotating part has the first connection and the second connection.

[0011] Advantageously, the compressed air and the material can be guided separately from the rotating part via the fixed part to the spray gun, for which purpose separate air passages and material passages can be provided in the rotating part and the fixed part.

[0012] Furthermore, the turned part can comprise a first connection element, which may have the first connection, and a second connection element, which may have the second connection and is rigidly connected to the first connection element. The first connection element can form a central section forming a through-hole and a side cut forming the first connection. Furthermore, the second connection element can form a material channel located in an axial direction, i.e., parallel to the axis of rotation, downstream of the second connection.

[0013] According to the invention, the fixed part comprises a nozzle element that can be rigidly connected to the spray gun and an axle element rigidly connected to the nozzle element, on which the rotating part is rotatably mounted. The axle element can be inserted into the passage. With a first end of the axle element received in the passage, the axle element can project into the material channel formed by the second connection element, which engages in a widened first end of the passage and is located axially behind the second connection. The axle element can be in a material-tight contact with the second connection element via a seal of the connection device. Radially on the outside, in a contact area of ​​the seal, the first connection element can form an overflow through which the material can escape to the outside in the event of a defect in the seal.A gap, a lubricating layer, or a bearing, in particular an axial sliding bearing, may be provided between a flange of the axle element and the second connecting element. With a second end of the axle element projecting beyond the passage in the axial direction, the axle element may extend into a material channel formed by the nozzle element, which engages in a widened second end of the passage. This channel may bend perpendicular to the axial direction, essentially in a direction of material discharge from the spray gun, and lead to a material outlet of the nozzle element. This outlet may be connected via a material line to a material inlet of the spray gun located on a shaft of the spray gun.

[0014] According to the invention, the axle element has a material channel. Thus, the material supplied via the material line can pass from a material source, to which the material line may be connected, through the material channel of the second connecting element, subsequently through the material channel of the axle element, further subsequently through the material channel of the nozzle element, and further subsequently through the material line to a mixing chamber of the spray gun arranged in the shaft.

[0015] Advantageously, the connection device can include a bearing arrangement with at least one bearing, via which the rotating part can be rotatably connected to the fixed part. The bearing can be a thrust bearing or a radial bearing. Furthermore, the bearing can be a rolling bearing or a sliding bearing. The bearing arrangement can, in particular, include two or three bearings. The bearing, which can be provided between the flange and the second connection element, can be part of the bearing arrangement.

[0016] In an advantageous embodiment, the bearing arrangement can comprise at least one axial bearing, preferably an axial rolling bearing. The bearing arrangement can further comprise a radial bearing, preferably a radial sliding bearing. The sliding bearing can be arranged adjacent to the axial rolling bearing in the axial direction. By means of the axial bearing, the rotating part can be attached to the fixed part particularly easily along the axial direction and yet still be rotatably connected to the fixed part.For example, the axial bearing can be attached to the flange and to a shoulder formed in the passage of an inner wall of the central section, which is provided axially downstream of the flange. This serves, on the one hand, to fix the rotating part supported by the axial bearing along the axial direction relative to the fixed part and, on the other hand, preferably together with the sliding bearing, to enable the rotational movement of the rotating part relative to the fixed part about the axis of rotation. The axial bearing can preferably be a rolling bearing, in particular a ball bearing. The bearing arrangement can include a further axial bearing, in particular an axial sliding bearing, which can be arranged adjacent to the axial bearing in the opposite direction, in particular between the flange and the second connecting element.

[0017] To guide compressed air from the rotating part to the stationary part independently of any angle of rotation between the stationary and rotating parts, the stationary part or the nozzle part can have or form an air channel. The rotating part, the first connecting element, or the central section can have or form an annular channel for the compressed air, which can open into the air channel, such that the compressed air can be guided from the annular channel into the air channel regardless of the angle of rotation between the stationary and rotating parts. The annular channel can be bounded in the axial direction by the stationary part or nozzle element.

[0018] Advantageously, the connection device or the nozzle part can be arranged on the spray gun in such a way that the air channel of the fixed part or nozzle part can lead to an air inlet of the handle or open into an air channel of the handle located downstream of the air inlet in the axial direction.

[0019] Advantageously, the rotating part or the first connecting element or the side section can have or form an air channel, preferably at an angle to the axis of rotation, running from the first connection to the annular channel.

[0020] Thus, the compressed air supplied via the air line can pass from a compressed air source, to which the air line can be connected, through the air channel of the first connection element or side section, then through the ring channel of the first connection element or central section, then through the air channel of the nozzle element and then through the air channel of the handle to reach the mixing chamber.

[0021] The fixed part or nozzle part can have or form a material outlet, which can be connected via the material line to the material inlet of the spray gun located on the shaft of the spray gun. The connection device or spray gun can include the material line.

[0022] Advantageously, the connecting device allows the material to be guided parallel to the axis of rotation from the rotating part to the fixed part.

[0023] The connection device may include a fastening element for attaching the connection device or nozzle element to the spray gun. The fastening element may be designed such that the connection device can be detachably attached to the spray gun, in particular by screwing it on. For example, the fastening element may be a union nut with an internal thread that can be screwed onto an external thread of the handle.

[0024] The spray gun according to the invention for atomizing a material using compressed air comprises a connection device according to the invention.

[0025] Advantageously, the spray gun can comprise a handle, a shaft, a mixing chamber, a nozzle assembly, a valve assembly, and a trigger. By actuating the trigger, the operator of the spray gun can feed the material into the mixing chamber, where it interacts with the compressed air flowing into the chamber upon actuation of the trigger. This allows the material to then be atomized and dispensed through a nozzle of the nozzle assembly. The spray gun can comprise a housing that includes or forms the handle and the shaft. The handle can, preferably at its end, have or form an air inlet and an air channel located axially downstream of the air inlet, so that the compressed air can enter the spray gun via the air inlet and reach the mixing chamber via the air channel. Furthermore, the spray gun can have or form a material inlet arranged on the shaft.The housing is designed to allow the material to reach the mixing chamber. It can accommodate the mixing chamber, the nozzle assembly, and the valve assembly. The spray gun is advantageously suited for painting. The dispensed material can therefore be, in particular, a paint or varnish.

[0026] In the inventive method for operating a spray gun designed for atomizing a free-flowing material using compressed air, an air line is connected to a first connection of a connection device of the spray gun and a material line is connected to a second connection of the connection device, wherein, by means of the connection device designed as a rotary joint, the first connection and the second connection are rotated relative to the spray gun about a common axis of rotation, particularly when the spray gun is rotated, wherein the connection device comprises a fixed part that is stationary relative to the spray gun and a rotating part that is rotatably connected to the fixed part, wherein the rotating part has the first connection and the second connection, wherein the fixed part comprises a nozzle element that can be fixedly connected to the spray gun, and wherein the fixed part has an axle element that is fixedly connected to the nozzle element.comprising on which the rotating part is rotatably mounted, wherein the axle element has a material channel.

[0027] For the advantageous effects of the method according to the invention, reference is made to the description of advantages of the connection device according to the invention.

[0028] Further advantageous embodiments of the method according to the invention result from the feature descriptions of the dependent claims relating to device claim 1.

[0029] According to the invention, a connection device is used for a spray gun designed for atomizing a free-flowing material using compressed air, wherein the connection device has a first connection for connecting an air line and a second connection for connecting a material line, wherein the connection device is designed as a rotary joint such that the first connection and the second connection are rotatable relative to the spray gun about a common axis of rotation, wherein the connection device comprises a fixed part that is stationary relative to the spray gun and a rotating part rotatably connected to the fixed part, wherein the rotating part has the first connection and the second connection, wherein the fixed part comprises a nozzle element that can be fixedly connected to the spray gun, and wherein the fixed part comprises an axle element that is fixedly connected to the nozzle element and on which the rotating part is rotatably mounted.wherein the axle element has a material channel.

[0030] For the advantageous effects of the use according to the invention, reference is made to the description of advantages of the connection device according to the invention.

[0031] Further advantageous embodiments of the use according to the invention result from the feature descriptions of the dependent claims relating to device claim 1.

[0032] A preferred embodiment of the invention is explained in more detail below with reference to the accompanying drawing.

[0033] They show: Fig. 1 a sectional view of a spray gun; Fig. 2 a detailed view of the Fig. 1 in the area of ​​a connection device for the spray gun.

[0034] A summary of Fig. 1 and 2Figure 1 shows a spray gun 10 for dispensing a flowable material using compressed air. The gun comprises a housing 11, which forms a handle 12 and a shaft 13. The spray gun 10 further includes a nozzle assembly 14 arranged at the end of the shaft 13, a mixing chamber 16 arranged upstream of the nozzle assembly 14 in the dispensing direction 15 of the material, and a valve assembly 17 arranged in the shaft 13, which is coupled to a trigger 18 arranged laterally on the shaft 13. The material can enter the spray gun 10 and thus reach the mixing chamber 16 via a material inlet 19 arranged laterally on the shaft 13, passing through a filter assembly 65.Compressed air can enter the spray gun 10 via an air inlet 20 formed at the end of the handle 12. Behind the air inlet 20, an air channel 21 formed by the handle 12 is located, through which the compressed air can reach the mixing chamber 16. By actuating the trigger 18, the operator of the spray gun 10 can then supply the material to the mixing chamber 16, where it interacts with the compressed air flowing into the mixing chamber 16 by actuating the trigger 18, so that it can subsequently be atomized and dispensed by means of a nozzle 22 of the nozzle assembly 14.

[0035] Furthermore, the spray gun 10 includes a connection device 23, which is attached to the handle 12 at its end by means of a fastening element 24. The connection device 23, designed as a pivot joint 25, comprises a fixed part 26 relative to the spray gun 10 and a rotating part 27 rotatably connected to the fixed part 26. The rotating part 27 has a first connection 28, to which an air line 29 is connected, and a second connection 30, to which a material line 31 is connected. The first connection 28 and the second connection 30 are rotatable relative to the spray gun 10 about a common axis of rotation 32, thus increasing the operator's freedom of movement.The connecting device 23 comprises a bearing arrangement 33 with an axial rolling bearing 34, a radial sliding bearing 36 arranged adjacent to the axial rolling bearing 34 in an axial direction 35 parallel to the axis of rotation 32, and an axial sliding bearing 54 arranged adjacent to the axial rolling bearing 34 in the opposite direction 35, by means of which the rotating part 27 is rotatably connected to the fixed part 26.

[0036] More specifically, the rotating part 27 comprises a first connecting element 37, which forms a central section 38 and a side section 39, the side section 39 forming the first connection 28, and a second connecting element 40, which forms the second connection 30 and is fixedly connected to the first connecting element 27. Furthermore, the fixed part 26 comprises a nozzle element 41, which is fixedly connected to the handle 12 by means of the fastening element 24, and an axle element 42, which is fixedly connected to the nozzle element 41 and on which the rotating part 27 is rotatably mounted via the bearing arrangement 33.

[0037] The axle element 42, which forms a material channel 43, is inserted into a passage 44 formed by the central section 38, wherein the axial rolling bearing 34, which is attached to a flange 45 of the axle element 42 and to a shoulder 47 provided in the axial direction 35 following the flange 45 and formed by an inner wall 46 of the central section 38 in the passage 44, firstly fixes the rotating part 27, which is supported on the axial rolling bearing 34, along the axial direction 35 relative to the fixed part 26 and, secondly, together with the radial sliding bearing 36, enables the rotational movement of the rotating part 27 relative to the fixed part 26 about the axis of rotation 32.With a first end 48 of the axle element 42 received in the passage 44, the axle element 42 projects into a material channel 50 formed by the second connecting element 40, which engages in a widened first end 49 of the passage 44 and is located axially downstream of the second connection 30. The axle element 42 rests material-tight against the second connecting element 40 via a seal 51 of the connecting device 23. Radially on the outside, in a contact area 52 of the seal 51, the first connecting element 42 forms an overflow 53 through which material can escape to the outside in the event of a defect in the seal 51. The axial sliding bearing 54 is provided between the flange 45 and the second connecting element 40.With a second end 55 of the axis element 42 projecting beyond the passage 44 in the axial direction 35, the axis element 42 projects into a material channel 57 formed by the nozzle element 41 engaging in a second widened end 56 of the passage 44, which in a further course of the material channel 57 bends perpendicular to the axial direction 35, essentially in the output direction 15 and leads to a material outlet 58 of the nozzle element 41, which is connected to the material inlet 19 via a material line 59 of the connection device 23.Thus, the material supplied via the material line 31 can pass from a material source (not shown here), to which the material line 31 may be connected, through the material channel 50 of the second connection element 40, then through the material channel 43 of the axis element 42, then through the material channel 57 of the nozzle element 41 and then through the material line 59 to reach the mixing chamber 16.

[0038] Furthermore, the nozzle element 41 forms an air channel 60, wherein the central section 38 or the widened second end 56 forms an annular channel 61 for the compressed air, which is bounded in the axial direction 35 by the nozzle element 41 and opens into the air channel 60, such that the compressed air can be guided from the annular channel 61 into the air channel 60 independently of any angle of rotation formed between the fixed part 26 or the nozzle element 41 and the rotating part 27 or the first connecting element 37. The first connecting element 37 is in airtight contact with the shaft element 42 via a seal 62 and with the nozzle element 41 via a seal 63. Furthermore, the nozzle element 41 is arranged on the handle 12 or the air inlet 20 such that the air channel 60 opens into the air channel 21. Furthermore, the side section 39 forms an air channel 64 running obliquely to the axis of rotation 32 from the first connection 28 to the annular channel 61.Thus, the compressed air supplied by means of the air line 29 from a compressed air source not shown here, to which the air line 29 may be connected, can pass through the air channel 64 of the first connection element 37, then the annular channel 61 of the first connection element 37, then the air channel 60 of the nozzle element 41 and then the air channel 21 of the handle 12 to reach the mixing chamber 16.

Claims

1. A connector unit (23) for a spray gun (10) for spraying a flowable material using compressed air, the connector unit having a first connector (28) for the connection of an air line (29) and a second connector (30) for the connection of a material line (31), the connector unit being configured as a swivel joint (25) in such a manner that the first connector and the second connector are rotatable around a shared rotation axis (32) relative to the spray gun, the connector unit comprising a fixed part (26) fixed relative to the spray gun and a swivel part (27) rotatably connected to the fixed part, the swivel part having the first connector and the second connector, the fixed part comprising a socket element (41) rigidly connectable to the spray gun (10), characterized in that the fixed part comprises an axis element (42) rigidly connected to the socket element, the swivel part (27) being rotatably mounted on said axis element (42), the axis element (42) having a material channel (43).

2. The connector unit according to claim 1, characterized in that the connector unit (23) is configured for being arranged on a handle (12) of the spray gun (10).

3. The connector unit according to claim 1 or 2, characterized in that the compressed air and the material are separately guidable from the swivel part (27) to the spray gun (10) via the fixed part (26).

4. The connector unit according to any one of the preceding claims, characterized in that the swivel part (27) comprises a first connector element (37), which comprises the first connector (28), and a second connector element (40), which comprises the second connector (30), said second connector element (40) being rigidly connected to the first connector element.

5. The connector unit according to any one of the preceding claims, characterized in that the connector unit (23) comprises a bearing arrangement (33) having at least one bearing via which the swivel part (27) is rotatably connected to the fixed part (26).

6. The connector unit according to claim 5, characterized in that the bearing arrangement (33) comprises at least one axial bearing, preferably an axial rolling bearing (34).

7. The connector unit according to any one of the preceding claims, characterized in that the fixed part (26) has an air channel (60), the swivel part (27) having a ring channel (61) for the compressed air, said ring channel (61) opening into the air channel in such a manner that the compressed air is guidable from the ring channel to the air channel irrespective of a rotation angle formed between the fixed part and the swivel part.

8. The connector unit according to claim 7, characterized in that the connector unit (23) is disposed such on the spray gun (10) that the air channel (60) of the fixed part (26) opens into an air channel (21) of a handle (12) of the spray gun.

9. The connector unit according to claim 7 or 8, characterized in that the swivel part (27) has an air channel (64) running from the first connector (28) to the ring channel (61), preferably at an angle to the rotation axis (32).

10. The connector unit according to any one of the preceding claims, characterized in that the fixed part (26) comprises a material outlet (58) which is connectable to a material inlet (19) of the spray gun via a material line (59), said material inlet (19) being disposed on a shaft (13) of the spray gun (10).

11. The connector unit according to any one of the preceding claims, characterized in that the material is guidable parallel to the rotation axis (32) from the swivel part (27) into the fixed part (26) by means of the connector unit (23).

12. The connector unit according to any one of the preceding claims, characterized in that the connector unit (23) comprises a fastening element (24) for fastening the connector unit to the spray gun (10).

13. A spray gun (10) for spraying a material using compressed air, said spray gun (10) comprising a connector unit (23) according to any one of the preceding claims.

14. A method for operating a spray gun (10) configured for spraying a flowable material using compressed air, an air line (29) being connected to a first connector (28) of a connector unit (23) of the spray gun and a material line (31) being connected to a second connector (30) of the connector unit, the first connector and the second connector being rotated relative to the spray gun around a shared rotation axis (32), in particular when rotating the spray gun, by means of the connector unit configured as a swivel joint (25), the connector unit comprising a fixed part (26) fixed relative to the spray gun and a swivel part (27) rotatably connected to the fixed part, the swivel part having the first connector and the second connector, the fixed part comprising a socket element (41) rigidly connectable to the spray gun (10), characterized in that the fixed part comprises an axis element (42) rigidly connected to the socket element, the swivel part (27) being rotatably mounted on said axis element (42), the axis element having a material channel (43).

15. A use of a connector unit (23) for a spray gun (10) configured for spraying a flowable material using compressed air, the connector unit having a first connector (28) for the connection of an air line (29) and a second connector (30) for the connection of a material line (31), the connector unit being configured as a swivel joint (25) in such a manner that the first connector and the second connector are rotatable around a shared rotation axis (32) relative to the spray gun, the connector unit comprising a fixed part (26) fixed relative to the spray gun and a swivel part (27) rotatably connected to the fixed part, the swivel part having the first connector and the second connector, the fixed part comprising a socket element (41) rigidly connectable to the spray gun (10), characterized in that the fixed part comprises an axis element (42) rigidly connected to the socket element, the swivel part (27) being rotatably mounted on said axis element (42), the axis element having a material channel (43).