Air cap and nozzle assembly for a spray gun, and spray gun

• US 10,464,076 B2
• Filed: 12/15/2016
• Issued: 11/05/2019
• Est. Priority Date: 12/21/2015
• Status: Active Grant

• Current Assignee: Sata GmbH & Co. KG (SATA Holding GmbH)
• Original Assignee: Sata GmbH & Co. KG (SATA Holding GmbH)
• Inventors: Kruse, Albrecht
• Primary Examiner(s): Gorman, Darren W
• Application Number:
  US15/379,972
• Publication Number:
  US 20170173600A1
• Time in Patent Office: 1,055 Days
• Field of Search: 239290, 239296-301
• CPC Class Codes: B05B 1/02 designed to produce a jet, spray, or other discharge of particular shape or nature, e.g. in single drops, or having an outlet of particular shapeB05B1/26, B05B1/28, B05B1/34 take precedence
• CPC Class Codes: B05B 1/14 with multiple outlet openings B05B1/02, B05B1/26 take precedence; with strainers in or outside the outlet opening
• CPC Class Codes: B05B 7/02 Spray pistols; Apparatus for discharge for spraying particulate material B05B7/14; with means for heating the material to be sprayed B05B7/16; with means for supplying fluent material to a discharge device B05B7/24
• CPC Class Codes: B05B 7/0815 with at least one gas jet intersecting a jet constituted by a liquid or a mixture containing a liquid for controlling the shape of the latter

Abstract

An air cap for a spray gun, in particular a paint spray gun, having at least one central opening, which is delimited by a mouth, and two horns, each having at least one inner and one outer horn air duct and one inner and one outer horn air opening. The spacing between the front end of the central opening and an axis which perpendicularly intersects the central axis of the central opening and runs through the center of an inner horn air opening is between 0.6 mm and 2.6 mm. The spray pattern generated by the air cap has a longer core region and a steeper transition of the layer thickness between the external region and the core region, compared to conventional air caps leading to improvement in coating quality. A nozzle assembly and a spray gun, in particular a paint spray gun, can have an air cap having the above properties.

Claims

1. An air cap for a spray gun comprising:

a central opening defined by a peripheral rim, the peripheral rim having a conical external face; and

two horns arranged on opposite sides of the central opening, each of the two horns having an inner air duct disposed in proximity to the central opening and extending inwardly from the respective horn toward the central opening and an outer air duct disposed further from the central opening than the inner air duct and extending inwardly from the respective horn toward the central opening;

wherein a space between a front end of the central opening and a point B at which a line extending from an axis of one of the inner air ducts perpendicularly intersects an axis of the central opening measures between 2.4 mm and 2.6 mm and an angle between the axis of the one of the inner air ducts and the axis of the central opening measures between 57° and

60°

.

2. The air cap according to claim 1, wherein a space between the front end of the central opening and a point C at which a line extending from an axis of one of the outer air ducts perpendicularly intersects the axis of the central opening measures between 6.0 mm and 6.6 mm.

3. The air cap according to claim 2, wherein the space between the front end of the central opening and the point C measures between 6.2 mm and 6.4 mm.

4. The air cap according to claim 1, wherein an angle between an axis of one of the outer air ducts and the axis of the central opening measures between 78°

and 82°

.

5. The air cap according to claim 4, wherein the angle between the axis of the one of the outer air ducts and the axis of the central opening measures between 79°

and 80.5°

.

6. The air cap according to claim 5, wherein the angle between the axis of the one of the outer air ducts and the axis of the central opening is a spot bore angle of the one of the outer air ducts and the angle between the axis of the one of the inner air ducts and the axis of the central opening is a spot bore angle of the inner air duct.

7. The air cap according to claim 6, wherein a ratio of the spot bore angle of the one of the outer air ducts to the spot bore angle of the one of the inner air ducts is between 1.2 and 1.6.

8. The air cap according to claim 1, wherein a space between one of the inner air ducts and one of the outer air ducts along the axis of the central opening measures between 3.3 mm and 5.8 mm.

9. The air cap according to claim 8, wherein the space between the one of the inner air ducts and the one of the outer air ducts along the axis of the central opening measures between 3.4 mm and 4.2 mm.

10. The air cap according to claim 1, wherein an internal diameter of at least one of the two inner air ducts measures between 1.1 mm and 1.3 mm.

11. The air cap according to claim 10, wherein the internal diameter of the at least one of the two inner air ducts is 1.2 mm.

12. The air cap according to claim 1, wherein an internal diameter of at least one of the two outer air ducts measures between 1.4 mm and 1.6 mm.

13. The air cap according to claim 12, wherein the internal diameter of the at least one of the two outer air ducts is 1.5 mm.

14. The air cap according to claim 1, wherein the space between the front end of the central opening and the point B at which the line extending from the axis of the one of the inner air ducts perpendicularly intersects the axis of the central opening is a spot bore height of the one of the inner air ducts and an internal diameter of the one of the inner air ducts measures between 1.1 mm and 1.3 mm.

15. The air cap according to claim 14, wherein a ratio of the spot bore height of the one of the inner air ducts to the internal diameter of the one of the inner air ducts is between 1.7 and 2.4.

16. The air cap according to claim 2, wherein the space between the front end of the central opening and the point C at which the line extending from the axis of the one of the outer air ducts perpendicularly intersects the axis of the central opening is a spot bore height of the one of the outer air ducts and an internal diameter of the one of the outer air ducts measures between 1.4 mm and 1.6 mm.

17. The air cap according to claim 16, wherein a ratio of the spot bore height of the one of the outer air ducts to the internal diameter of the one of the outer air ducts is between 3.8 and 4.5.

18. The air cap according to claim 1, wherein a front face of the air cap includes six control openings disposed in groups of three in a shape of a triangle on opposite sides of the central opening, a tip of each triangle aligned in a direction of the inner or outer air ducts.

19. The air cap according to claim 18, wherein the control openings have an angle of between 8°

and 12°

in relation to the axis of the central opening.

20. The air cap according to claim 1, wherein a front face of the air cap includes four control openings disposed in groups of two on opposite sides of the central opening, the groups aligned in a direction of the inner or outer air ducts.

21. The air cap according to claim 1, wherein an internal diameter of the central opening measures between 3.5 mm and 3.7 mm.

22. The air cap according to claim 1, wherein the conical external face of the peripheral rim of the central opening has an angle of between 25°

and 35°

in relation to the axis of the central opening.

23. The air cap according to claim 1, wherein an axis of at least one of the two inner air ducts and an axis of at least one of the two outer air ducts intersect at a point along the axis of the central opening.

24. The air cap according to claim 23, wherein a space between the front end of the central opening and the point of intersection of the axis of the at least one inner air duct and the axis of the at least one outer air duct measures between 7.5 mm and 8.5 mm.

27. A nozzle assembly for a spray gun comprising the air cap according to claim 1.

28. A spray gun comprising the nozzle assembly according to claim 27.

29. A spray gun comprising the air cap according to claim 1.

25. An air cap for a spray gun comprising:

a central opening defined by a peripheral rim, the peripheral rim having a conical external face; and

two horns arranged on opposite sides of the central opening, each of the two horns having an inner air duct disposed in proximity to the central opening and extending inwardly from the respective horn toward the central opening and an outer air duct disposed further from the central opening than the inner air duct and extending inwardly from the respective horn toward the central opening;

wherein a space between a front end of the central opening and a point B at which a line extending from an axis of one of the inner air ducts perpendicularly intersects an axis of the central opening is a spot bore height of the one of the inner air ducts and measures between 2.4 mm and 2.6 mm and an angle between the axis of the one of the inner air ducts and the axis of the central opening measures between 57° and

60°

; and

wherein a space between the front end of the central opening and a point C at which a line extending from an axis of one of the outer air ducts perpendicularly intersects the axis of the central opening is a spot bore height of the one of the outer air ducts and measures between 6.2 mm and 6.4 mm and an angle between the axis of the one of the outer air ducts and the axis of the central opening measures between 78° and

82°

.

26. The air cap according to claim 25, wherein a ratio of the spot bore height of the one of the outer air ducts to the spot bore height of the one of the inner air ducts is between 2.0 and 3.0.

30. A spray gun comprising the air cap according to claim 25.