SPRAY GUN

• US 3,688,990 A
• Filed: 08/04/1971
• Issued: 09/05/1972
• Est. Priority Date: 08/04/1971
• Status: Expired due to Term

• Current Assignee: N/A
• Original Assignee: N/A
• Primary Examiner(s): M. Henson Wood, Jr.
• Assistant Examiner(s): Edwin D. Grant
• Application Number:
  US05/168,855
• Time in Patent Office: 398 Days
• Field of Search: 239/518,524,15
• US Class Current: 239/524
• CPC Class Codes: B05B 5/032 for spraying particulate materials

Abstract

An optionally electrostatic spray gun is of the type wherein a carrier pressure fluid is supplied to an axial passage having its mouth at the tip portion of the gun, a deflecting head is provided centrally in front of the mouth for deflecting the carrier fluid flow annularly outwardly in transverse relation to the passage when emerging therefrom, and spraying material is atomized and entrained by the carrier flow as it sweeps past an orifice in the gun supplied with spraying material. In such a gun the orifice is arranged circumferentially around the mouth and emits the spraying material as an annular film into the carrier fluid flow substantially in counter-direction to the resultant deflection thereof.

Claims

1. An improved spray gun of the type wherein a carrier pressure fluid is supplied to an axial passage having its mouth at the tip portion of the gun, a deflecting means is provided centrally in front of said mouth for deflecting the carrier fluid flow annularly outwardly in transverse relation to said passage when emerging therefrom, and spraying material is atomized and entrained by said carrier flow at an orifice in the gun supplied with spraying material and passed by said flow, the improvement comprising:

a. a nozzle sleeve on said gun coaxially around said tip portion thereof and extending forwardly beyond said mouth;

b. passage means in said gun for supplying spraying material into said sleeve; and

c. an annular inwardly directed deflecting ridge on said sleeve spaced forwardly of said tip portion to provide said orifice between said ridge and tip portion annularly around the mouth of said passage.

2. Spray gun according to claim 1 in which said tip portion is tubular, said sleeve frusto-conical around said tip portion, and said ridge defines the orifice by a deflecting surface perpendicular to said passage.

3. A spray gun according to claim 2 in which said frusto-conical portion is countered by a cooperating bevelled surface on said tip portion, said tip portion having circumferentially spaced grooves, said bevelled surface directed towards said deflecting surface.

4. A spray gun according to claim 1 in which said deflecting means is a headed member comprising a stem portion supported with annular clearance in said passage and a head for deflecting the carrier flow emerging from said clearance.

5. A spray gun of the type wherein a carrier pressure fluid is supplied to an axial passage having its mouth at the tip portion of the gun, a deflecting head is provided centrally in front of said mouth for deflecting the carrier fluid flow annularly outwardly in transverse relation to said passage when emerging therefrom, a spraying material chamber rearwardly of said passage is supplied with spraying material, the flow of spraying material from said chamber is controlled by an axially movable needle valve, and spraying material is atomized and entrained by said carrier flow at an orifice in said gun in communication with said chamber and passed by said flow, the improvement comprising:

a. a nozzle plug on said gun providing a closure for the forward end of said chamber and having said tip portion and passage formed forwardly thereon;

b. a valve seat in said plug for said needle valve;

c. a nozzle sleeve on said nozzle plug coaxially around said tip portion thereof and extending forwardly beyond said mouth;

d. passage means in said plug connecting said seat with the interior of said sleeve; and

e. an annular inwardly directed deflecting ridge on said sleeve spaced forwardly of said tip portion to provide said orifice between said ridge and tip portion annularly around the mouth of said passage.

6. A spray gun according to claim 5 in which said tip portion is tubular, said sleeve frusto-conical around said tip portion, and said ridge defines the orifice by a deflecting surface perpendicular to said passage.

7. A spray gun according to claim 6 in which there is provided a frusto-conically converging secondary nozzle sleeve on said gun spaced around said sleeve to present an orifice therebetween directed towards said deflecting head, and means in said gun for supplying secondary pressure fluid into said secondary nozzle sleeve whereby a converging flow of secondary fluid is directed towards said head for modifying the annular shape of said carrier flow.