SPRAY GUN FOR APPLYING SOLID PARTICLES

• US 3,617,000 A
• Filed: 06/16/1969
• Issued: 11/02/1971
• Est. Priority Date: 06/16/1969
• Status: Expired due to Term

• Current Assignee: Kenneth E. Pollard, Richard O. Probst
• Original Assignee: Kenneth E. Pollard, Richard O. Probst
• Inventors: Pollard, Kenneth E., Probst, Richard O.
• Primary Examiner(s): Wood, Jr., M. Henson
• Assistant Examiner(s): Mar, Michael Y.
• Application Number:
  US04/833,352
• Time in Patent Office: 869 Days
• Field of Search: 239/3,15,142,143,144,302,303,307,308,339,526,591,602
• US Class Current: 239/706
• CPC Class Codes: B05B 5/032 for spraying particulate materials

Abstract

A spray gun for applying solid particles to an article includes a handle and a barrel member. The passageway for conveying a suspension of solid particles in a carrier gas is an elongated flexible tube which extends from the spray nozzle through a bore in the barrel member, the handle and outwardly from the gun to the source of coating material particles. Such a gun can also include an elongated insulator forming a passageway for highvoltage circuit means within the gun and curved between the grip portion of the handle and another bore in the barrel. A closure means of insulating material at the front of the barrel can include a portion projecting into the barrel to provide electrical insulation for the connection between the high-voltage circuit means and an electrode mounted on the front of the spray gun. The closure means can also provide a means for attaching a spray nozzle at the front of the gun.

Claims

1. An electrostatic spray gun for charging and depositing powder particles comprising, a handle including a grip portion, a barrel of nonconducting material including two bores, a closure means including a projecting portion at the rear and adapted to enter the forward end of the barrel, and including two bores in alignment with the bores of the barrel, an elongated flexible tube forming a passageway for powder particles from the gun and angled to pass within the grip portion of the handle and one of the bores of the barrel and of the closure means, an elongated insulator forming a passageway for circuit means within the gun and angled to fit within the grip portion of the handle and the other of the bores of the barrel and the closure means, said closure means including at its forward end a compression member on the axis of the elongated flexible tube and threadedly engaging the closure means, and means to grip the elongated flexible tube as the compression member is threadedly engaged.

2. The electrostatic spray gun of claim 1 wherein the elongated flexible tube angled between the barrel and the grip portion of the handle forms a smooth curve.

3. The electrostatic spray gun of claim 1, including a spray nozzle attached to the closure means on the axis of the elongated flexible tube and providing a seal with the compression member.

4. The electrostatic spray gun of claim 1 wherein the compression member is a cylinder around the elongated flexible tube and threaded into the forward end of the bore carrying the elongated flexible tube, and the means to grip the elongated flexible tube is an elastic member located in position to be compressed between the compression member and the closure means as the compression member is threaded into the bore.

5. The electrostatic spray gun of claim 1 wherein the barrel includes a barrel member comprised of a thin-walled tube and an insert providing the two bores.

6. An electrostatic spray gun for charging and depositing powder particles comprising, a handle including a grip portion, a barrel member of nonconducting material including two bores, a closure means including a projecting portion at the rear adapted to enter the forward end of the barrel and including two bores in alignment with the bores of the barrel, an elongated flexible tube forming a passageway for powder particles within the gun and curved to pass within the grip portion of the handle and one of the bores of the barrel and of the closure means, an elongated insulator forming a passageway for circuit means within the gun and gradually curved to fit within the grip portion of the handle and the other of the bores of the barrel and the closure means, said closure means including at its forward end means for attaching a spray nozzle on the axis of the bore for said elongated flexible tube and including means to electrically connect circuit means in the bore of said insulator to a forward surface of the closure means.

7. The electrostatic spray gun of claim 6 including means at the forward end of the closure means to fasten the elongated flexible tube within the spray gun.

8. The electrostatic spray gun of claim 7 wherein the means to fasten the elongated flexible tube includes a cylindrical compression member around the elongated flexible tube and threadedly engaging the closure means.

9. The electrostatic spray gun of claim 8 including a spray nozzle mounted on the compression means, attached to the closure means, and providing a seal between the compression means an the spray nozzle.

10. A gun for spraying solid particles, comprising, a handle, a barrel projecting from the handle and including a bore, spray forming means attached to the forward end of the barrel, an elongated flexible tube including a passageway for conveying solid particles suspended in gas passing within the handle and the bore of the barrel, the tube curving gradually in the gun, means to fasten the elongated flexible tube with the gun, the flexible tube adapted to be moved with respect to the gun when the tube is unfastened from the gun, the passageway of said elongated flexible tube being substantially smooth walled and having a substantially uniform cross section from a source of solid particles to the spray forming means whereby the solid particles flow to the spray forming means in a substantially stable suspension.

11. The gun of claim 10 including a cylindrical compression member around the elongated flexible tube and threadedly engaging the forward end of the barrel, and means compressed as the compression member is threadedly engaged to grip the elongated flexible tube.

12. The gun of claim 11 including a seal member between the cylindrical compression member and the spray forming means.

13. The electrostatic spray gun of claim 6 wherein the elongated flexible tube has a substantially uniform cross section from a source of solid particles to the spray nozzle whereby the solid particles flow to the nozzle is a substantially stable suspension.

14. A spray gun for spraying solid particles comprising a barrel including a bore, a handle including a portion depending at an angle from the barrel, a spray nozzle adjacent to the forward end of the barrel, an elongated flexible tube including a passageway for conveying solid particles suspended in a gas within the portion of the handle depending at an angle from the barrel and within the bore in the barrel, the passageway of the flexible tube curving gradually in the handle to reduce erosion of the passageway at the curve by solid particles flowing thereby and the passageway having a substantially uniform cross section from a source of solid particles to the spray nozzle whereby the solid particles flow to the nozzle in a substantially stable suspension.

15. The spray gun as claimed in claim 14 wherein a closure means is adjacent the forward end of the barrel and attaches the nozzle to the forward end of the barrel, the closure means engaging the elongated flexible tube to locate the tube within the forward end of the barrel.

16. The spray gun as claimed in claim 14, wherein the barrel includes two bores, the second of the bores including an elongated insulator for electrical circuit means, the elongated insulator includes a curved portion in the handle.

17. A spray gun for spraying solid particles comprising a barrel including a bore, a handle including a portion depending at an angle from the barrel, and means adapted to be moved with respect to the barrel, the means including a passageway for conveying solid particles suspended in a gas within the portion of the handle depending at an angle from the barrel and within the bore in the barrel, the passageway curving gradually in the handle to reduce erosion of the passageway at the curve by solid particles flowing thereby and the passageway having a substantially uniform cross section from a source of solid particles to a spray nozzle connected to the bore whereby solid particles flow to the nozzle in a substantially stable suspension.