US2470718A

US2470718A - Spray gun

Info

Publication number: US2470718A
Application number: US772779A
Authority: US
Inventors: Donald J Peeps
Original assignee: DeVilbiss Co
Current assignee: DeVilbiss Co
Priority date: 1947-09-08
Filing date: 1947-09-08
Publication date: 1949-05-17
Anticipated expiration: 1966-05-17

Description

46 l l 49 5| l 37 36 35 27 2625 B? INVENTOR DONALD J. Peeps ATTORNEY Patented May 17, 1949 'Donald J. Peeps, Toledo, 0hio, signor to The De Vilbiss Company, Toledo, Ohio, a corpoi'a.-`

tion of (lhlo Application September 8, 1941, Serial No. '172,719'v This invention relates to a spray gun of the type using air for atomizing the material to be spray applied and which is designed for manual support and manipulation.

It is particularly desirable in view of the continuous use usually made of such a spray gun that it be light and compact in order to be .nontiring and easy to handle for the operator.

Because oi the mechanism involved the length of hand spray'guns are inclined to be greater than desirable. This characteristic makes it more d imcult to direct the gun at various surfaces.

The primary purpose of this invention is to provide a spray gun with parts designed to permit the length to be shortened.

An associated object is to reduce the weight of the gun.

Another object is to simplify the design.

The means of accomplishing these purposes includes the combining into a single part a valve seat for the valve controlling the flow of the air to the horns with means for dividing the air into separate streams, one for the horns and the other for the center port of the air cap, and baille means lfor distributing the air of both streams circumferentally about the axis of the spray nozzle.

The'invention in its preferred form has other objects and advantages which may be noted cn reading the following description and referring to the accompanying drawing in which:

Figure 1 is a vertical sectional view of a spray gun embodying my invention;

Figure 2 is a perspective view of the combination valve seat, air dividing and baille part; and

Figure 3 is a rear elevational view of the lower portion of the trigger.

The spray gun shown in Figure 1 has a main body portion I with a depending handle 2. An air valve 3 for-'controlling the flow of atomizing air to the nozzle, generally referred to as 4, and the spray material needle valve 5 are both moved to open position through a rearward pull of the nger trigger 6.

Air is supplied to the spray gun through a ilexible hose (not shown) connected to the threaded nipple 1. The air travels from this nipple upwardly through passage 8 into air valve chamber 9. The air valve 3 is held against its seat III on the valve cage II by spring I2.

A valve stem I3 extends forwardly through the cage which has a packing chamber I4. The packing is held within this chamber by retainlng disc I5 which is clamped in place by split ring I5 sprung into groove I'I. The exterior 1 claim. (ci. zaag-140.1)

2 end of the stem I3 has motivating contact with a rearwardly bent tongue portion Il of a small -Isolate I9 integrally tlxed to the rear side of trigger The .distance between the air valve and the trigger is less in this gun than in conventional designs as the packing around the air valve stem inthe latter type is held in place by a protruding packing nut.

.The use of disc I5 and ring I5 has permitted the .trigger to be moved closer to the air valve. This results in the body being foreshortened to a like degree reducing the weight of the gun as well as its length.

The air after passing air valve l flows through ports 20 in thelcage II. From here it proceeds upwardly through passage 2i and around casing 22 enclosing the needle valve spring 23. The 'air continues along horizontal passage 24. At the forward end of this passage the air for the horns passes valve 25 into bore 26 and then intoannular chamber 21. From here the air moves forwardly through a series of circumferentially spaced ports 28 into the chamber 29 within the air cap retaining ring 30. The two passages 3l communicate with this chamber and deliver the air therefrom to the horn discharge ports 32.

The other portion of the air from horizontal passage 24 proceeds unregulated into annular space 33` which joins at the top with the passage 24. From this space the air moves forwardly through a series of circumierentially spaced ports 34 entering the rear side of member 35. These ports terminate behind a like series of ports 36 in ange 31 of the material discharge tip 38. From the space beyond the ange between `the tip 38 and air cap 39 this air ilows through the annular discharge port 40. The member 35 is set in a xed position by the mating of opening 54 on its rear side with a locating pin extending from the body.

It may be noted that member 35 not only provides the valve seat for valve 25 but also distributes the regulated air circumferentlally in chamber 21 before delivering it forwardly to the horn ports and in addition provides spaced ports 34 to deliver forwardly unregulated air to the central discharge port of-the air cap. Two or three separate parts are normally utilized to serve the purposes accomplished by this single part l5.

The use of this compact member permits the forward portion of the spray gun to be reduced in length.

The design of the trigger s is directed to minimizing the space it requires in relation to the lengthwise dimension of the spray gun. It is a thinned wall stamping with rearwardly indented shape to receive the operators fingers and to keep the trigger from contact with material supply nipple 4| and hose attached to the nipple. In order toretain the suitable contour for the nngers and to also present a flat contacting surface for the valve stem I3 the small bent plate I9 is welded to the main trigger body. To provide a straight pull for the operators fingers on the trigger, the latter is positioned directly below its pivot pin 42. l

Parts of the spray gun not heretofore explained, include the packing nut 43 which holds packing 44 around the stem of the material needle valve. The hollow adjusting nut 45 determines the degree of opening of the material valve as the end of the needle is stopped against its inner surface. The air valve 25 is mounted on a. stem 46 which has exteriorly on its other end an adjusting knob 41. Upon turning the knob the valve is moved axially due to the threaded engagement of the stem with bushing 48. 'I'he spring 49 is tensioned between a cross pin 54 through the stem and packing retaining disc il. It thus serves the dual purpose of keeping the packing 52 tight around.

the stem and furnishing a tension to resist any undesired turning of the knob.

The plugged bore 53 in the handle of the gun is necessary for machining the body beyond the air valve and the removal of stock also lightens the gun.

While there is herein described and shown a preferred embodiment of the invention, it is understood that the invention is not limited thereto as, variations thereof may be made Without departing fromthe spirit of the invention.

. I claim:

' In a spray gun ofthe type described, a body having a spray material duct andan air duct, an internally threaded cylindrical nipple `extend- .ing axially from the forward end of the gun with which the spray material duct communicates, the air duct having its outlet above the nipple, a spray material tip with an axial bore and a ported peripheral flange, said tip being threadedly connected to the nipple, an air cap fitted over the tip and seating against the forward side of the edge of thefiange, said cap being provided with a central air port surrounding the outlet of the tip and with two opposed side air ports which have supply passages with entrances radially outside oi' the seating contact between the cap and the ange, an annular air dividing and bailling member tting tightly in reenforcing engagement over the nipple and `held between the'rear side oi' the flange and the forward end of the' body, there being an air chamber between the member and the body communicating with the air duct. said annular member having passages therethrough terminating on its forward face radially inside of the contacting surface between the rear side of the ange and the member, said passages directing air from the chamber forwardly through the ported tip flange to the central air port of the cap, said member also having secondary air passage means directing air from the chamber forwardly past the outer edge of the ange to the two opposed side air ports of the cap, the said secondary air passage means having a single entering port on the rear side of the member directly in line with the outlet of the air duct, a valve seating in said entering port, and a valve shank. extending rearwardly and axially Within the air duct and with a manually operable part extending exteriorly from the rearward portion of the spray gun.

DONALD J. PEEPS.

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

UNITED STATES PATENTS Number Name Date 1,969,205 Carr Aug. 7, 1934 2,004,303 Wahlin June 1l, 1935 2,102,303 Bramsen et al Dec. 14, 1937 2,295,445 Anshicks Sept. 8, 1942 2,303,280 Jenkins Nov. 24, 1942 2,348,568 Pellar May 9, 1944 2,380,608 Palm July 31, 1945 2,416,923 Jenkins Mal'. 4, 1947 2,417,546 DeGiers Mar. 18, 1947 FOREIGN PATENTS Number Country Date 783,021 France Mar. 25, 1935