Apparatus and methods for purging material application device

• US 20090107397A1
• Filed: 10/31/2007
• Published: 04/30/2009
• Est. Priority Date: 10/31/2007
• Status: Active Grant

• Current Assignee: Nordson Corporation
• Original Assignee: Nordson Corporation
• Inventors: Campbell, Donna, Sanner, Michael R., Mather, Brian
• Granted Patent: US 8,726,831 B2
• Time in Patent Office: Days
• US Class Current: 118/302
• CPC Class Codes: B05B 15/55 using cleaning fluids
• CPC Class Codes: B05B 5/032 for spraying particulate materials
• CPC Class Codes: B05B 7/1486 for spraying particulate material in dry state
• CPC Class Codes: B08B 9/0328 by purging the pipe with a gas or a mixture of gas and liquid

Abstract

Purge method and apparatus for a manual spray gun or coating material application device, in which purge air is introduced into the device through a handgrip portion that is manually held during a coating operation. Purge air first enters the coating material flow path after the purge air enters the handgrip portion.

Claims

1. Purge apparatus, comprising:

a spray gun comprising a nozzle and a handle that is manually gripped by an operator during a coating operation,

a coating material inlet to said handle,

a coating material flow path that extends through at least a portion of said handle to said nozzle,

a purge air inlet to said handle that is separate from said coating material inlet.

2. The apparatus of claim 1 comprising an electrode air wash inlet that is separate from said coating material inlet and said purge air inlet.

3. The apparatus of claim 1 wherein said handle comprises a purge air flow path through which purge air flows from said purge air inlet into said coating material flow path.

4. The apparatus of claim 3 wherein said purge air flow path comprises an annulus about a coating material inlet member, and a passageway between said purge air inlet and said annulus.

5. The apparatus of claim 4 wherein said coating material inlet member comprises said coating material inlet, with coating material flowing through said coating material inlet member and through said coating material flow path to said nozzle during a coating operation.

6. The apparatus of claim 4 wherein said coating material inlet member comprises a hose connector adapted to have a supply hose having a first end connected thereto, said supply hose having a second end that receives coating material from a coating material supply.

7. The apparatus of claim 5 comprising a coating material flow tube at least partially disposed with said handle and defining at least a portion of said coating material flow path, said hose connector is connected with said coating material flow tube by a quick release connector.

8. The apparatus of claim 7 wherein said hose connector telescopes into said coating material flow tube with said annulus defined between respective adjacent walls thereof.

9. The apparatus of claim 8 wherein said hose connector comprises an inner end that inserts into said coating material flow tube, with purge air flowing from said purge air inlet through said passageway into said annulus then into said coating material flow tube.

10. The apparatus of claim 9 wherein at least a portion of the purge air entering said coating material flow tube from said annulus flows along a surface that includes a shoulder that is angled other than transverse a longitudinal axis of said coating material flow tube.

11. The apparatus of claim 2 comprising an electrode that charges coating material from said nozzle, with electrode wash air flowing from said air wash inlet through an air wash passageway to a tip of said electrode, said air wash passageway being separate from said coating material flow path.

12. The apparatus of claim 4 wherein purge air flows into said annulus at an angle that produces a swirling flow of the purge air through said annulus.

13. The apparatus of claim 1 wherein purge air enters said coating material flow path during a purging operation at a location that purges coating material from said coating material inlet, through a barrel of said gun and through said nozzle, said purge air inlet being disposed in the base of said handle.

14. The apparatus of claim 13 comprising a flexible boot disposed on said handle, said boot providing a pressure responsive seal between a purge air flow path and said coating material flow path.

15. The apparatus of claim 14 wherein said boot comprises a purge air passage and a flexible wall that moves in response to purge air pressure to allow purge air to flow into said coating material flow path.

16. The apparatus of claim 15 wherein said boot is connectable to a source of pressurized air.

17. A coating material application system, comprising:

a coating material application device, a supply of coating material, a source of purge air and a control system that controls coating and purging operations,

said device comprising a nozzle and a handle that is manually gripped by an operator during a coating operation,

a coating material inlet to said handle,

a coating material flow path that extends through at least a portion of said handle to said nozzle,

a purge air inlet to said handle that is separate from said coating material inlet.

18. The apparatus of claim 17 comprising an electrode air wash inlet that is separate from said coating material inlet and said purge air inlet.

19. The apparatus of claim 17 wherein said handle comprises a purge air flow path through which purge air flows from said purge air inlet into said coating material flow path, said purge air inlet being disposed in the base of said handle.

20. The apparatus of claim 19 wherein said purge air flow path is part of a flexible boot.

21. The apparatus of claim 19 wherein said purge air flow path includes a portion that is integrally formed with said handle.

22. Method for purging a coating material spray gun, comprising:

supplying coating material to a coating material inlet during a coating operation,

supplying purge air to a pure air inlet during a purging operation,

said coating material flowing through a coating material flow path that is at least partially disposed within a handle that is manually gripped by an operator during a coating operation,

said purge air flowing into said handle along a purge air flow path that is separate from said coating material flow path.

23. The method of claim 22 comprising said purge air flowing from said purge air flow path into said coating material flow path at a location that is within said handle.

24. The method of claim 22 comprising supplying an electrode wash air flow into said handle along an electrode air wash flow path that is separate from said coating material flow path and said purge air flow path.

25. Purge apparatus, comprising:

a spray gun comprising a nozzle and a handle that is manually gripped by an operator during a coating operation,

a coating material inlet to said handle,

a coating material flow path that extends through at least a portion of said handle to said nozzle,

a purge air inlet to said handle that is separate from said coating material inlet,

a flexible boot disposed on said handle, said boot providing a seal between at least a part of said purge air flow path and said coating material flow path.

26. The apparatus of claim 25 wherein said boot comprises a purge air passage and a flexible wall that moves in response to purge air pressure to allow purge air to flow into said coating material flow path.

27. The apparatus of claim 26 wherein said flexible wall forms a face seal against a passage into said coating material flow path when purge air is not applied.

28. A coating material application device, comprising:

a handgrip that is manually held by an operator during a coating operation,

a coating material flow path at least a portion of which is disposed within said handgrip,

a purge air inlet on said handgrip for supplying purge air into said coating material flow path during a purge operation, purge air being introduced into said handgrip before entering said coating material flow path.

29. The device of claim 28 comprising a coating material inlet into said handgrip that is separate from said purge air inlet.