Air cap arrangement and spray gun

Abstract

An air cap arrangement and a spray gun. The air cap arrangement comprises an air cap, an air cap ring and a retaining ring. The air cap ring comprises a groove configured to extend on the circumferential inner surface of the air cap ring. The air cap also comprises a groove configured to extend on the circumferential outer surface of the air cap, and the retaining ring is arranged in the groove of the air cap ring and the groove of the air cap to limit the axial movement of the air cap within the air cap ring.

Claims

1. An air cap arrangement for a spray gun, said air cap arrangement comprising: an air cap; an air cap ring; and a retaining ring, wherein the air cap has a circumferential outer surface extending longitudinally, and the air cap ring has a circumferential inner surface extending longitudinally, the air cap ring comprises a groove configured to extend on the circumferential inner surface of the air cap ring, the air cap comprises a groove configured to extend on the circumferential outer surface of the air cap, the retaining ring is arranged in the groove of the air cap ring and the groove of the air cap to limit the axial movement of the air cap within the air cap ring, the air cap ring further comprises a protrusion configured to protrude radially from the circumferential inner surface of the air cap ring, the groove of the air cap ring is further configured to extend circumferentially and to be located closer to a front end of the air cap ring than the protrusion, the air cap further comprises a step configured to protrude radially from the circumferential outer surface of the air cap, the groove of the air cap is further configured to extend circumferentially and to be located closer to a front end of the air cap than the step, and a front face of the step, which faces the front end of the air cap, is configured to contact against a rear face of the protrusion, which faces a rear end of the air cap ring, when the air cap arrangement is assembled.

2. The air cap arrangement according to claim 1, wherein the circumferential inner surface of the rear end of the air cap ring is provided with a thread.

3. The air cap arrangement according to claim 1, wherein the retaining ring is configured to be flexible such that the air cap can be pressed out of the air cap ring by only pressing the air cap toward the rear end of the air cap ring.

4. The air cap arrangement according to claim 3, wherein the retaining ring is a polygonal ring.

5. The air cap arrangement according to claim 3, wherein the retaining ring is made of elastic material.

6. The air cap arrangement according to claim 3, wherein the retaining ring is made of rubber material.

7. The air cap arrangement according to claim 1, wherein the rear end of the air cap is provided with a circular protrusion protruding backward, and an end, protruding backward, of the circular protrusion is provided with a circular cone surface.

8. The air cap arrangement according to claim 1, wherein the step and the protrusion each run over the whole circumference.

9. The air cap arrangement according to claim 1, wherein at least one of the step and the protrusion is discontinuous.

10. The air cap arrangement according to claim 1, wherein the retaining ring is an entire ring.

11. The air cap arrangement according to claim 1, wherein the retaining ring comprises a cut.

12. The air cap arrangement according to claim 1, wherein the front face of the step and the rear face of the protrusion each extend in a radial direction of the air cap arrangement.

13. The air cap arrangement according to claim 1, wherein the groove of the air cap is configured to be separated from the step of the air cap in an axial direction of the air cap arrangement.

14. The air cap arrangement according to claim 13, wherein the protrusion of the air cap ring is configured to be located entirely between the groove of the air cap and the step of the air cap in the axial direction when the air cap arrangement is assembled.

15. The air cap arrangement according to claim 1, wherein the step of the air cap is configured to protrude radially further than the circumferential outer surface of the air cap at a front side of the groove of the air cap.

16. A spray gun comprising: a gun body that includes a spray gun head; and an air cap arrangement, the spray gun head of the gun body being connected with the air cap arrangement, wherein the air cap arrangement comprises an air cap, an air cap ring, and a retaining ring, a rear end of the air cap ring is connected with the spray gun head, the air cap has a circumferential outer surface extending longitudinally, and the air cap ring has a circumferential inner surface extending longitudinally, the air cap ring comprises a groove configured to extend on the circumferential inner surface of the air cap ring, the air cap comprises a groove configured to extend on the circumferential outer surface of the air cap, and the retaining ring is arranged in the groove of the air cap ring and the groove of the air cap to limit the axial movement of the air cap within the air cap ring, the air cap ring further comprises a protrusion configured to protrude radially from the circumferential inner surface of the air cap ring, the groove of the air cap ring is further configured to extend circumferentially and to be located closer to a front end of the air cap ring than the protrusion, the air cap further comprises a step configured to protrude radially from the circumferential outer surface of the air cap, the groove of the air cap is further configured to extend circumferentially and to be located closer to a front end of the air cap than the step, and a front face of the step, which faces the front end of the air cap, is configured to contact against a rear face of the protrusion, which faces a rear end of the air cap ring, when the air cap arrangement is assembled.

17. The spray gun according to claim 16, wherein the rear end of the air cap is provided with a first circular protrusion protruding backward, and an end, protruding backward, of the first circular protrusion is configured in a circular cone surface, the spray gun further comprises a paint nozzle that is provided with a second circular protrusion protruding forward, and an end, protruding forward, of the second circular protrusion is configured in a circular cone surface, and the circular cone surface of the second circular protrusion is configured to contact against the circular cone surface of the first circular protrusion when the air cap arrangement is assembled.

18. The spray gun according to claim 16, wherein the air cap, the air cap ring, and the retaining ring are configured such that the air cap can readily rotate with respect to the air cap ring around a spray axis to adjust spray orientation when the air cap arrangement is assembled.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The drawings constitute a portion of the description for further understanding of the present disclosure. These drawings illustrate the embodiments of the present disclosure and explain the principle of the present disclosure together with the description. In the drawings, the same part is represented by the same reference sign. In the drawings,

(2) FIG. 1 is a schematic diagram illustrating a spray gun according to the prior art.

(3) FIG. 2 is an enlarged schematic diagram illustrating a sectional view of the air cap arrangement and the spray gun head according to the prior art.

(4) FIG. 3 is an enlarged schematic diagram illustrating a sectional view of the air cap arrangement and the spray gun head according to the prior art.

(5) FIG. 4 is a disassembling diagram illustrating an air cap arrangement according to Example 1 of present disclosure.

(6) FIG. 5A is a schematic diagram illustrating the air cap according to Example 1 of present disclosure.

(7) FIG. 5B is a schematic diagram illustrating the air cap with the retaining ring according to Example 1 of present disclosure.

(8) FIG. 6A is a schematic diagram illustrating a front view of the air cap ring with the retaining ring according to Example 1 of present disclosure.

(9) FIG. 6B is a schematic diagram illustrating a rear view of the air cap ring with the retaining ring according to Example 1 of present disclosure.

(10) FIG. 7 is a schematic diagram illustrating an assembled air cap arrangement according to Example 1 of present disclosure.

(11) FIG. 8 is a schematic diagram illustrating a sectional view of the air cap arrangement and the spray gun head according to Example 1 of present disclosure.

(12) FIG. 9A is a schematic diagram illustrating the air cap arrangement according to Example 2 of present disclosure.

(13) FIG. 9B is a schematic diagram illustrating the air cap with the retaining ring according to Example 2 of present disclosure.

DETAILED DESCRIPTION

(14) The front direction mentioned herein refers to a direction pointed by the spray gun head, and the rear direction refers to a direction substantially opposite to the front direction; and the up direction mentioned in the present application refers to a direction substantially opposite to the handle direction in a normal hand-held operation state when the handle points downwards. The left side or right side mentioned herein refers to a side of the spray gun or spray gun body corresponding to the operator's left hand or right hand, viewing from the operator's angle, in the normal hand-held operation state when the spray gun head points to the front and the handle points downwards.

Example 1

(15) FIG. 4 is a disassembling diagram illustrating an air cap arrangement according to Example 1 of present disclosure. As shown in FIG. 4, the air cap arrangement proposed by Example 1 of present disclosure comprises an air cap 5, an air cap ring 6 and a retaining ring 7 having a cut 71 in this embodiment. The air cap ring 6 is connected with the spray gun head 23 on the gun body 2 of the spray gun 1.

(16) FIG. 5A is a schematic diagram illustrating the air cap according to Example 1 of present disclosure. As shown in FIG. 5A, the front end of the air cap 5 has two two lateral horns 53, and each of the lateral horns 53 comprises horn air nozzle(s) 531. The air cap 5 comprises: a step 51 configured to protrude radially from the circumferential outer surface of the air cap 5; and a groove 52 configured to extend circumferentially on the circumferential outer surface of the air cap 5 and locate closer to the front end of the air cap 5 than the step 51.

(17) FIG. 5B is a schematic diagram illustrating the air cap with the retaining ring according to Example 1 of present disclosure. As shown in FIG. 5B, the retaining ring 7 can be arranged in the groove 52 of the air cap 5. And since the retaining ring 7 is polygonal, the contact area between the retaining ring 7 and the groove 52 is small, thus the friction between them is small.

(18) FIG. 6A and FIG. 6B respectively illustrates the front view and rear view of the air cap ring with the retaining ring according to Example 1 of present disclosure. And as shown in FIGS. 6A and 6B, a protrusion 61 is still arranged on the circumferential inner surface of the air cap ring 6. However, the protrusion 61 is located closer to the rear end of the air cap ring 6 than that of the prior art. Furthermore, a groove 62 is arranged on the circumferential inner surface of the air cap ring 6 and closer to the front end of the air cap ring 6 with respect to the protrusion 61. And furthermore, the retaining ring 7 can be arranged in the groove 62 of the air cap ring 6.

(19) As shown in FIGS. 6A and 6B, since the retaining ring 7 is polygonal, the contact area between the retaining ring 7 and the groove 62 is small, thus the friction between them is small.

(20) It should be noted that in FIGS. 5B and 6B, both the air cap 5 as well as the air cap ring 6 are equipped with a retaining ring 7, only to show the position of the retaining ring 7 in the groove 52 and the groove 62 when the air cap 5 and the air cap arrangement is assembled, i.e. when the air cap 5 and the air cap ring 6 are connected. However, the assembled air cap arrangement preferably comprises just one single retaining ring 7. However, of course it can also comprise several retaining rings arranged in several grooves.

(21) The air cap 5 can be inserted from the rear end of the air cap ring 6 arranged with the retaining ring 7, to form the air cap arrangement, as shown in FIG. 7. As an alternative to this preferred solution, it can be provided that the air cap 5 can be equipped with the retaining ring 7 before inserting it from the from the rear end of the air cap ring 6.

(22) FIG. 8 is a schematic diagram illustrating a sectional view of the air cap arrangement and the spray gun head according to Example 1 of present disclosure. As shown in FIG. 8, the front surface of the step 51 can contact against the rear surface of the protrusion 61 of the air cap ring 6 to prevent the air cap 5 from moving forward with respect to the air cap ring 6.

(23) Furthermore, since the groove 52 is located in front of the step 51, when the air cap 5 is inserted into the air cap ring 6 from the rear of the air cap ring 6, the retaining ring 7 disposed in the groove 62 will enter the groove 52 of the air cap 5. Thus the retaining ring 7 can prevent the air cap 5 from moving backward with respect to the air cap ring 6.

(24) Thus, in the air cap ring arrangement above, the air cap 5 can rotate in the air cap ring 6 around the spray axis, and the air cap 5 is not or hardly moveable in the direction of spray axis.

(25) The step 51, the groove 52 and the protrusion 61 advantageously run over the whole circumference of the air cap 5 or the air cap ring 6 respectively; the retaining ring 7 is advantageously cut 71 at one position, As shown in FIGS. 4 and 5B.

(26) Since the retaining ring 7 is flexible to some extent, the air cap 5 can be pressed out only by pressing the air cap 5 toward the rear end of the air cap ring 6 when the user wants to remove the air cap 5 from the air cap ring 6. Therefore, compared to prior art, it is easy to remove the air cap 5 from the air cap ring 6 and clean it.

(27) As shown in FIGS. 4 and 5B, since the retaining ring 7 comprises a cut 71, the retaining ring 7 may be more flexible to make it easier to remove air cap 5 from the air cap ring 6.

(28) Furthermore, since the retaining ring 7 is arranged in the air cap ring 6 rather than exposed to outside, therefore the foreign matter is prevented from attaching on or near the retaining ring 7 such that the spray gun is kept clean.

(29) Furthermore, as shown in the FIG. 8, retaining ring 7 is arranged in the air cap ring 6, thus it is unnecessary to protrude the air cap 5 out of the air cap ring 6 too far, thus the length of the air cap 5 is reduced such that the weight of the air cap 5 is reduced and the material is saved. And since the retaining ring 7 is arranged in the air cap ring 6, the spray gun is aesthetically pleasing.

(30) Furthermore, as shown in FIGS. 4 and 5B, the retaining ring 7 is a hexagonal ring, thus the contact area between the retaining ring 7 and the groove 62 of the air cap ring 6 is small, and the contact area between the retaining ring 7 and the groove 52 of the air cap 5 is also small. Thus, the friction between the retaining ring 7 and the air cap ring 6 and the friction between the retaining ring 7 and the air cap 5 are both small, so that the air cap 5 can readily rotate with respect to the air cap ring 6 to adjust the orientation of the spray flat. At the same time, as it is already the case with spray guns according to the state of the art, the air cap 5 is fixed when the air cap ring 6 is screwed tight to the spray gun head 23, so that the orientation of the flat spray is fix and cannot be changed unintentionally.

(31) Furthermore, as shown in FIG. 8, since the retaining ring 7 is arranged in the groove 52 disposed on the circumferential outside surface of the air cap 5, thus the retaining ring 7 doesn't lie within the air path. Thus, the flow of the air is not disturbed so that the flow of the air can be kept stable.

(32) Furthermore, as shown in FIG. 8, a circular protrusion 54, which surrounds the spray axis, is arranged on the rear surface of the air cap 5, and the outside surface of end of the circular protrusion 54 is formed as a circular cone surface 541. A circular protrusion 27 is also arranged on the paint nozzle 26, and the inner surface of the end of the protrusion 27 is also configured as circular cone surface 271. The air cap 5 can be aligned with respect to the paint nozzle 26 through making the circular cone surface 541 of the circular protrusion 54 to contact against the circuit cone surface 271 of the circular protrusion 27. In the state of the art, the connection manner of the air cap 5 and the spray gun head 23 limits the movement of the air cap 5, and impedes the air cap 5 from aligning with the paint nozzle 26. However, with the present disclosure, since the retaining ring 7 is not lying tightly in the groove 62, but has space (As shown in FIG. 8), it doesn't impede the air cap 5 from aligning with the paint nozzle 26.

(33) The spray gun according to the present disclosure and a spray gun having an air cap arrangement according to the present disclosure may further have a paint needle 10, a needle sealing arrangement comprising a sealing element 12, a pressure spring 14 and a fixing element 16. The sealing arrangement seals the paint conducting channel in the spray gun body against the outer areas. The paint needle 10 is sliding within the axial symmetrical sealing element 12 when the spray gun is activated, i.e. when the trigger is pulled, by which the sealing element wears out. However, due to the pressure spring 14, which lies against the fixing element 16 and presses against the sealing element 12, the sealing element 12 always lies in its seat tightly. The spray gun can further comprise an air distribution ring 17, a colored marking ring 18, a sealing element 20 in the paint cup connection, a hook, a pressure measuring device and other components known in the state of the art.

(34) Accordingly, through the structure of the air cap arrangement of present Example 1, it is easy to remove the air cap 5 from the air cap ring 6 for cleaning; the air cap 5 can readily rotate with the air cap ring 6 to adjust the orientation of the spray flat; the air flow is more stable because it is not disturbed by the retaining ring 7; and the air cap 5 can be aligned with the paint nozzle 26 more precisely. Therefore, the air cap arrangement of Example 1 involves advantageous technical effect while overcoming the problem in the prior art.

(35) However, the example described above is only used to explain the disclosure, but should not be viewed as the limitation to the disclosure. For example, although the retaining ring 7 used in the Example 1 is hexagon, the retaining ring 7 can also be any other polygonal ring with different number of edges, such as pentagon and heptagon. Furthermore, although the retaining ring 7 in the above Example 1 comprises a cut at the position 71, the retaining ring 7 can also be an entire ring. Although the step 51 and the protrusion 61 in the Example 1 run over the whole circumference of the air cap 5 or the air cap ring 6, the step 51 and/or the protrusion 61 can be discontinuous, as long as they may prevent the air cap 5 from moving forward.

Example 2

(36) FIG. 9A is a schematic diagram illustrating the air cap arrangement according to Example 2 of present disclosure. And FIG. 9B illustrates a schematic diagram of an air cap 5 and retaining ring 7 according to Example 2 of present disclosure.

(37) As shown in FIGS. 9A and 9B, the air cap arrangement described in Example 2 is substantively similar to that of Example 1, and the difference only lies in the retaining ring 7 used in Example 2 and the ring 7 described in Example 1.

(38) As shown in FIG. 9B, the retaining ring 7 used in Example 2 is a elastic holding ring made of rubber or other elastic material. Similar technical effect as that of Example 1 can be achieved through arranging the retaining ring 7 in the grooves of the air cap ring 6 and the air cap 5 (not shown). In this Example, it is preferred to first arrange the retaining ring 7 into the groove 52 of the air cap 5 and then insert the air cap 5 from the rear end of the air cap ring 6 into the air cap ring 6 to form the air cap arrangement. However, it can of course also be provided to first arrange the retaining ring 7 into the groove 62 of the air cap ring 6 and then insert the air cap 5.

(39) And preferably, the retaining ring 7 is an entire circular ring. However, as for present disclosure, the retaining ring 7 can be cut to increase its flexibility. Furthermore, the retaining ring 7 can also be configured as a polygonal ring as described in Example 1.