US2497625A - Spray gun - Google Patents

Description

Feb., M1, E95@ H. M. NQRWHQK SPRAY GUN Filed Aug. 3

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m Kw www In m Patented Feb. 14, 1950 UNITED STATES ienrENT OFFICE SPRAY GUN Henrietta M. Norwick, Oakland, Calif.

Application August 3, 1944, Serial No. 547,826

the device in such manner that the operating parts will be exposed to a minimum wear, replace-- ment of the relatively quick wearing parts may be accomplished in an easy manner and without disturbing the assembly of the rest of the parts, and no loose tting or undue wear of the parts will be created by constantlyr taking the device apart and putting it together in order to keep the device clean and smooth operating.

A further object of the invention is to design the device in such manner as to require a minimum of machining operations, eliminate the need of transversely separable body sections and the attendant means for securing the sections together, and provide for effective sealing of the liquid from the operating mechanism within the gun.

The invention possesses other objects and features of advantage, some of which, with the foregoing, Will be set forth in the following description of the preferred form of the invention which is illustrated in the drawing accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted within the scope of the invention as set forth in the claims.

Referring to said drawings:

Figure 1 is a side View of the spray gun of my invention.

Figure 2 is an enlarged longitudinal sectional view of the gun.

Figure 3 is a transverse sectional view of the gun taken on the line 3-3 of Figure 2.

Figure 4 is a view similar to Figure 1, but showing a different liquid feed arrangement.

Figure 5 is a perspective view of the relatively separated packing unit and its normally axially abutting coupling ring.

The gun as illustrated in the drawings, comprises a body 6 preferably formed as an aluminum casting and having a barrel portion 'I and a handle portion 8 projecting angularly therefrom. Extending longitudinally through the barrel is a` bore 9 within which are contained telescopic tubes I2 and I3 through which air under pressure is passed for forcing the liquid from the gun in a spray or jet. Tube I3 which is slidably tted 2 Claims. (Cl. 299-140) over tube I2 is slidably mounted in a bearing I4 in the bore 9, while the tube. I2 is iitted within a bore I6 aligned with bore 9 and provided in a cap Il having a screw threaded connection with the barrel 1, tube I2 being held in xed position by means of a nut I6 which serves to clamp against the outer end of the cap the iianges I9 and 20 of the tube I2 and an air hose nipple 22.

The material is arranged to be ejected from the device through a nozzle 23 at the forward end of the device, and such nozzle is provided at the outer end of a T-shaped body extension 24 designed to be .connected to the barrel through means of a set of rings 26 and 21. Within extension 24 is formed a chamber 28 for the reception of the liquid spray material, the material being supplied to the chamber as shown in Figure 2 through a branch 29 adapted for connection to a flexible hose 30 leading to a suitable source ci material. Tube I3 is arranged to extend through both rings 26 and 2l and into chamber 28 where it is of reduced diameter and forms a valve stem shaped as a valve 3| at its outer extremity, the vaive being engageable with a valve seat 32 pro-- vided at the inner end of the tip 33 of nozzle 23. As will be clear, when the valve is seated, the liquid in chamber 28 Will be prevented from escaping through the nozzle, but when the valve is retracted the liquid will be ejected by the air forced through the tubes, it being understood that air under pressure is supplied from a suitable source connected to the nipple 22.

As a means ci closing and sealing the chamber 28 at the end through which the valve tube I3 I l enters the same, there is provided a packing unit 3d including a housing 36 which is tightly fitted by a driving t in the inner side of the extension and contains an insert 31 of packing material designed to embrace the outer-side of the tube. Ring 26 is arranged for direct attachment to the barrel 'I threaded portions 40 and 4I. The attachment between the rings 26 and 21 is afforded through cooperating external and internal threaded portions 35 and 35'. Ring 2l secures extension 24 against longitudinal displacement by means of a ange 38 extending over a collar 33 on housing 36. The ring 26 serves not only as a part of the means for supporting the extension on the end of the barrel, but forms a means of closing such end independent of the unit 34, the ring being provided with a solid end wall 4I which closes the bore 9 and forms a bearing for the tube. In this way when the rings 26 and 27 are separated as when the extension is detached for replacing the packing 31, the exposed end of the barrel will be protected. At the same time whenever it is necessary to have access to the interior of the barrel such as in the course of assembly of the inside working parts of the gun or when cleaning of the interior of the barrel becomes desirable, it is merely necessary to unscrew the ring 26 from the adjoining threaded end of the barrel. This feature is of considerable importance in practice as it permits the detachment and reattachment of the extension unit without disassembly of the parts in the main body and Without disturbing the relationship and connection between the extension body, the packing unit 34 and the rings 26 and 2. In reference to the foregoing, it may be explained that the gun in its present form, is designed for operation with the extension rotated to a position in which the liquid feed branch 2S is disposed at the bottom of the extension as shown in Figure 2, or to a position as shown in Figure 4 in which the branch 29 is at the top and at'- tached to a hopper d2. To lock the extension in either of said positions, the housing 36 With which the extension body is secured by a driving t (so that the extension 24 and the packing unit 3d are practically a single integral part), is designed to interlock with the ring 26 and preferably at their opposing faces, the interlock being provided for by engagement of teeth 63 of the ring in diametrically opposed recesses 4d formed between segmental shoulders 46 in the housing.

The valve 3l is urged to closed position by a coil spring M interposed between a shoulder 48 on the inner side of the barrel and a washer 49 at the inner end of the tube, and retraction of the tube against the spring to effect ejection of the liquid is aorded by means of a trigger 5! pivoted to the body and engaging another trigger 52 having a forked end 5l which engages a collar 53 on the tube i3. Both triggers are arranged within a cavity Sil in the body, and while the trigger 'i may be installed by being inserted into the cavity through a slot 56, the trigger 52 due to the spread of the forked portion 51 and the narrowness of the cavity 54, has to be inserted through the open end of the bore 9 with the ring 26 removed. While detachment oi the ring 26 from the barrel is normally required only at relatively rare intervals, the detachment of the ring 21 with the associated extension parts from the ring 26 is usually necessary at frequent periods in View of the desirability of cleaning the chamber and` replacing the packing after the work or the use I of the gun is completed. By reason of the above, both rings and are preferably formed of steel as in this manner no appreciable wear of the connecting threads and consequent loose fitting and connection of the rings will be produced regardless of the frequency with which the extension is removed for cleaning. Conversely both the body and the extension may be formed of a relatively soit material and cast as of aluminum, as the connection between such members and the rings is seldom disturbed.

I claim:

l. ln a spray gun having a main body provided with a tubular open-ended barrel, a handle extending frorn the body, a tubular air-conducting member extending through said barrel, an axially movable tubular valve stem telescopically engaged with the tubular member and extending outwardly from one end of the barrel, an extension connected with said barrel at the end thereof through which the tubular valve projects, said extension having therein inlet and outlet passages for fluid, said outlet passage being associated with and adapted to be opened and closed by the tubular valve upon axial movement of the latter, and a trigger for moving said tubular valve in combination with a seal for restraining leakage of liquid from said extension and along said tubular valve comprising a closure member having a bore therein slidably receiving said tubular valve and secured in an end of said barrel, a plug member secured in said extension coaxially with and having therein a bore through which the tubular valve extends and is slidable, said plug member having therein an annular recess concentric with and surrounding said tubular valve, said recess having an open end facing the closure member of said barrel, compressible packing material in said recess, and means for releasably securing said extension to the end or said barrel whereby said closure member overlies and closes the open end of said recess.

2. In a spray gun having a main body provided with a tubular open-ended barrel, a handle extending from the body, a tubular air-conducting member extending through said barrel, an axially movable tubular Valve stem telescopically engaged with the tubular member and extending outwardly from one end of the barrel, an extension connected with said barrel at the end thereof through which the tubular valve projects, said extension having therein inlet and outlet passages for iiuid, said outlet passage being associated with and adapted to be opened and closed by the tubular valve upon axial movement of the latter, and a trigger for moving said tubular valve in combination with a seal for restraining leakage of liquid from said extension and along said tubular valve' comprising a closure member having a bore therein slidably receiving said tubular valve and secured in an end of said barrel, said closure member having in a transaxial face thereof a plurality of indentations bordering the periphery'of said tubular valve stem, a plug member secured in said extension coaxially with and having therein a bore through which the tubular valve extends and is slidable, said plug member having therein an annular recess concentric with and surrounding said tubular valve, said recess having an open end facing the closure member of said barrel, compressible packing material in said recess, lugs on said plug member registerable with and reee'vable in the indentations of said closure member for securing the closure and plug members together against relative rotation, means interposed between and securing together the closure member and the plug member, and a portion of said closure member overlying the open end of said recess for retaining the packing material therein.

HENRIETTA M. NORWICK.

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

UNITED STATES PATENTS Number Name Date 96,545 Brady Nov. 19, 1869 2,054,136 Pfaff et al. Sept. 15, 1936 FOREIGN PATENTS Number Country Date 521,668 France July 18, 1921

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