US2479507A

US2479507A - Spray gun nozzle

Info

Publication number: US2479507A
Application number: US530626A
Authority: US
Inventors: Donald J Peeps
Original assignee: DeVilbiss Co
Current assignee: DeVilbiss Co
Priority date: 1942-02-16
Filing date: 1944-04-12
Publication date: 1949-08-16
Anticipated expiration: 1966-08-16

Description

D. J. PEEPS SPRAY GUN NOZZLE Original Filed Feb. 16, 1942' Aug. 16, 1949.

til l INVENTOR DONALD J. PEEPS ATTORNEY Patented Aug. 16, 1949 Donald J. Peeps, Toledo, Ohio, assigning to The. De Vilbiss Company, Toledo, Ohio, a. corpora! tion of Ohio Original application February 16, 1:942; Serial No.- 431,036. Divided and this applicati'on April 12,

19.44, Serial No. 530,626

i 2 Claims. (01'. gee-14931 This invention relates to a type using air for atomization a The subject matter of; this application was originally a part of co-pending application, Serial No. 431,036 filed February 16, 1942, now abandoned, and this application is a division of the earlier application.

The principal object of the invention is to provide a nozzle structure which is easily assembled and has effective sealing means between the liquid and air passages.

A further object is to provide a spray gun which is compact and simple in construction. Other objects will be apparent from the following description and claims when read in conjunc tion with the accompanying drawing in which there is a single figure presenting a central vertical, longitudinal section through the forward end of a spray gun embodying my invention.

Referring to the drawing, the body of the spray gun is indicated at l. Mounted thereon is liquid discharge tip 2. This is threadedly engaged to the body at 3. This threaded area on the body is circumferentially interrupted by a series of longitudinal grooves 4 providing paths for the atomizing air.

Held over and against the tip by retaining ring 5, is air cap 6.

Coating liquid reaches the discharge tip 2 through entering passage 1 and axial bore 8. The outlet 9 of the tip is controlled by the conventional needle valve Ill.

The air for atomizin the coating material and forming the spray into fan shape travels forwardly through main air passage II. A branch thereof, not shown, carries some of the air into the circular chamber l3, past the baffle 26, then through the peripherally spaced channels I 4 in the inwardly facing flange l5 of the cap, hence into the space l6 between the cap and the tip, and along the horn passages I! to the opposed discharge ports l8. This air is utilized for flattening the spray discharge into fan shape while also improving the atomization.

The air to be utilized for the primary atomization continues along main air passage ll, until it enters annular space l9 beneath the rearward skirt section of the tip 2. From here it passes through the grooves 4, ports 28 through the tip, and from chamber 2| between the tip and the cap out annular discharge port 22 in atomizing relation to the material issuing from the tip.

The liquid tip 2 has two longitudinally spaced, annular, tapered seating surfaces which are held against similar complementary surfaces on the spray gurrof: the

body I. The more forwardly positioned pair at 2,3; is adjacent to. the location of the; ports. through the tip. The taper of these, contacting surfaces to the longitudinal axis of the gun is approximately thirty degrees. The adjoining surfaces of the rearwardly positioned pair of tapered seating faces 24 have a common taper inclined at an angle of five degrees.

The tubular skirt 25 of the liquid tip 2 is thin walled and will spread slightly when thrust with sufiicient force over the complementary taper on the forward end of the gun body. As a consequence these tapered surfaces may be pressed together or further wedged after they have been brought into initial contacting and sealing relation. This extra movement is advantageous should the forwardly positioned complementary tapers at 23 fall a trifle short of meeting when the 5 tapers at 24 first contact each other.

In this event by further pressing the tip against the gun body the slightly tapered sections at 24 will wedge telescopingly until the other complementary tapers at 23 meet in sealing contact. This extra give in the contacting relation of the slightly tapered sections may be helpful in compensating for any eccentricity in the spacings of the various tapers as well as any variances longitudinally of the body and tip axis. An effective seal at each tapered seatin point is important since the forward seat separates the liquid passage from the main atomizing air passage and the rearward seat separates the atomizing air passage from the passage for the air going to the horns for forming the discharged spray into fan shape.

The hardened steel ordinarily used in liquid tips is well suited to this invention as this metal provides the thin-walled skirt 25 with ample strength and also with resilience to incline it back to its original shape when removed temporarily from a wedged fit upon the spray gun body.

While the invention has been described in a preferred form, it should be understood that various modifications may be made without departing from the spirit or scope of the claims appended hereto.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a spray gun, a spray gun body, a liquid discharge tip fastened to the forward end of the body, an expansible thin-walled skirt on the rearward end of the tip, a slightly tapered annular seating surface on the inner side of the skirt inclined at an angle of less than ten degrees to the longitudinal axis of the tip, an outwardly facing complementary tapered surface on the spray gun body against which the seating surface on the skirt is thrust, a second set of annular seating surfaces on the tip and the body, liquid and air passages between the body and tip separated from each other by the two sets of seating surfaces, and means for drawing the tip against the body to bring the complementary the rearward end of the tip, a seating surface tapered at an angle of approximately five degrees to the longitudinal axis of the tip on the inner side of the skirt, an outwardly facing complementary tapered surface on the spray gun body against which the seating surface on the skirt is thrust, a second set of complementary annular seating surfaces on the tip and the body, and means for drawing the tip against the body to bring the complementary surfaces into sealing contact, the laterally resilient skirt on the tip spreading to permit the tip to be drawn further against the body should the second set of seating surfaces be not fully in sealing contact when the seating surfaces of the set includin that on theskirt of the tip initially come together.

DONALD J. PE'EPS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,004,033 Buzzard et al. June 4, 1935 2,146,416 Bramsen et al. Feb. '7, 1939 2,249,771 MacMartin July 22, 1941