US2699958A - Extension spray gun structure - Google Patents

Description

Jan. 18, 1955 H. w. BEACH EXTENSION SPRAY GUN STRUCTURE Filed Jan. 11, 1950 l'lJ - 9 INVENTOR. HOWARD WARRENBEACH Armmzrs v 4 M a H w & & k N u a h n A v I. HW I m a. Q. Q uzV/ \\\i \\w m w. R v? Q Q 9 Q N TIN Unite tates Patent EXTENSION SPRAY GUN STRUCTURE Howard Warren Beach, Montville, N. J., assignor to Eclipse Air Brush Co., Newark, N. J., a corporation of New Jersey Application January 11, 1950, Serial No. 137,953

1 Claim. (Cl. 28522) This invention relates to an extension spray gun pipe assembly of the type used to spray atomized paint and other fluids on surfaces located so they are inconvenient to spray with a hand-held spray gun. In this type, the atomized and atomizing fluids are separately conducted to a spray head from which the spray is ejected, in the manner practiced in the case of hand-held guns.

An extension spray gun has the spray head mounted on one end of a relatively long pipe assembly to the other end of which a valve assembly connects so as to control the fluid flows. The operator can move the spray head to otherwise inconveniently reached locations byholding the valve assembly end of the gun and he can control the spray action through this valve assembly. Usually the spray head is made so it ejects the spray at an angle to the pipe assembly, because this makes the operation of the gun more convenient.

' In developing the present invention, the inventor had as one objective the development of an extension spray gun having a construction permitting it to be manufactured and serviced easier and less expensively than is possible with prior art constructions. The inventor desired to make the pipe assembly in the form of telescoped pipes held separably together in a more convenient fashion and so as to more readily permit separttion of the various pipes when servicing the gun. All of these objectives or aims are accomplished by the present invention.

A specific example of an extension spray gun embodying this invention is illustrated by the accompanying drawings and described hereinbelow. The following description explains the operation and principles of the invention. Once they are understood, the principles may be incorporated in other forms than are specifically illustrated bythe accompanying drawings. The features of the invention may prove applicable to other types, of spray guns, and those skilled in the various arts'other than the spray gun art may find it advantageous to use certain or even all of these features. The' manner of constructing the illustrated gun is obvious once its constructional details are known.

Having reference to these accompanying drawings, the various individual figures are as follows:

Figure 1 is a side elevation of the gun with the features of the invention displayed by sectioning, the'long pipe assembly being shown broken to compact the figure to practical dimensions.

Figure 2 is a cross-section taken on the line in Fig. 1 and is for the purpose of displaying the arrangement of the plural valves, which cannot be exposed very well in Fig. 1. e

In this illustrated gun, an angle spray head assembly 1 includes a connection shank 2 formed with axially superimposed pipe-connection holes 3 and 4. The hole 3has a small diameter while the hole 4 has a large diameter, as these holes are compared to each other. The hole 3 receives the fluid flow of the material, such as paint, to be atomized, and the hole 4 receives the compressed air or other atomizing fluid. The details of the nozzle head or nose piece assembly, shown on the spray head 1, are not illustrated in detail or explained because they are immaterial to understanding the invention.

A pipe assembly is provided by a small-diameter pipe 5 and a large-diameter pipe 6, the latter being telescoped over the small pipe 5. The small pipe 5 is large enough properly to carry the fluid flow of the atomized material, while the large pipe 6 is sufliciently larger to, form an annular space around the smaller pipe which properly passes the flow of air or other atomizing fluid. Both the holes 3 and 4 are internally threaded and the ends of the pipes 5 and 6, adjacent these holes, are externally threaded and screwed into these holes at the spray-head end of the pipe assembly. Sufficient tapers are provided to make these screw joints fluid-tight. Since the parts are threaded together, tension on the pipe 5 can pull on the connection hole 3 with the spray head 1 then pushing or applying compression to the pipe 6 through its connection at the hole 4.

The pipes 5 and 6 may be of any length and are, therefore, shown broken. The idea is that they should be long enough to permit the operator conveniently to manipulate the spray head 1 in situations where the usual hand spray gun is not so convenient to handle.

At the end of the pipe assembly opposite the spray head 1, the small pipe 5 is externally screw threaded. The large pipe 6 is finished with a smooth cylindrical surface while its end edge is externally chamfered at 7. The chamfered surface 7 is provided with a good machine finish.

This chamfered pipe-end surface 7 is engaged by the correspondingly chamfered surface 8 of an' annular cap 9 having a ferrule or sleeve 10 with a cylindrical inside fitting the cylindrical outside of the pipe 6. This cap 9 is further formed to provide an inwardly extending annular flange 11 through which an annular series of relatively small holes 12 are axially formed. This flange 11 provides an internally screw-threaded hole 13 inside of the series of holes 12.

An externally and internally scf'ewwthreaded bushing 14 is screwed into the bushing hole '13 and onto the threaded end of the small pipe 5. This threaded end and both threaded surfaces of the bushing hole and the threaded surface of the flange hole 13 are all cylindrical. There is no taper. This bushing 14 has an outwardly projecting head 15 which may be engaged by a wrench, and the cap 9 has an annularly reduced outer end '16 which may also be engaged by a wrench. It is immatcrial Whether these wrench-engaging surfaces are burred by the wrench being roughly used.

Now it is possible to explain how the pipe assembly is put together. First, the small pipe 5 has its sprayhead end screwed tightly into the hole 3 of the spray head connection 2. Next, the large pipe 6 is slipped or telescoped over the small pipe 5, and the corresponding end of this large pipe is screwed tightly into the large hole 4. The hole 3 is axially superimposed in the hole 4 but it need not be radially registered therewith. Furthermore, the hole 3 need not be concentric to the'hole 4.

Going to the opposite end of the pipe assembly, the nextstep is to slip the sleeve 10 of the cap 9 over the outside of that end of the large pipe 7 with the respectively chamfered surfaces 7 and 8 intercontacting. Then, by screwing the bushing 14 onto the threaded end of the small pipeand into the threaded hole of the flange '11 ex tendinginwardly from the sleeve of the cap 9, assembly is completed. Tightening is effected by turning the bushing 14 on the small pipe end while permitting the sleeve ltl to rotate on the pipe 6, or by holding the bushing 14 stationary while rotating the cap, or as may be required to get proper tightening. The head 15 and the reduced surface 16 permit the use of wrenches during this operation. Since the wrench surfaces are spacedfrom all the other gun parts, it is immaterial Whether they are burred or battered.

. With the cap 9 thoroughly tightened, all the parts of the pipe assembly are held tightly together. The small pipe 5 works as a tension bar pulling on its threaded i connection with the bushing 14 andat the hole 3 of the spr y he 1- The l rg pipe 6. works. as a compression member with the spray head 1 pushing or compressing the pipe 6 through the connection and large hole 14, with the corresponding compression applied at the opposite.

1 end through the bushing 14 and cap 9. This holds the chamfered surfaces 7 and 8 fluid-tightly together while the ferrule or sleeve 10 of the cap 9 provides the otherwise smooth exterior of the valve end of the pipe 6. with a coupling or union shoulder. The pipe assembly issvery rigid, since it is a stressed assembly.

The valve arrangement includes a valve casing 17 made in the form of a handle and providing an internally screw-threaded hole or recess 18 at its front end. This recess 18 is substantially larger in diameter than the outside diameter of the large pipe 6. The pipe assembly is fastened in this recess 18 by a collar or coupling 19 providing a smoothly cylindrical bore 20 that fits the outside of the ferrule 10 of the cap 9, the outside of this part 10 being correspondingly smoothly finished. The forward end of this collar 19 has an internal flange 21, providing a bore that snugly but slidingly fits the outside of the large pipe 6.

When the collar 19 is slid backwardly along the pipe 5, the inner end of the flange 21 engages the front end of. the sleeve 10 so that the collar 19 forms a rotative coupling or union element. This collar 19 extends backwardly and provides an externally threaded end 22 fitting inside of the internally threaded recess 18 in the end of the valve casing 17. If the pipe 6 had a larger diameter than is illustrated, the collar 19 might be large enough so that the external threads of. its ends 22 would directly engage the internal threads of the recess 18. Since the pipe 6 is shown with a smaller diameter, an externally and internally threaded bushing 23 is interposed for the purpose of obtaining a proper fit. When the collar 19 is firmly screwed in the recess 18, the pipe assembly is fastened to the casing 17 fluid-tightly respecting fluid loss to the outside.

The inside of the end 15 of the bushing 14 is charnfered to the hole through it, and the valve casing 17 has a bore 25 in the center of the bottom of the recess 18. This bore 25 is provided with screw threads. A nipple 26 has an externally threaded mounting-end screwed into this hole 25, while its other end provides a nose piece which is chamfered at 27 corresponding to the chamfer 24. These two chamfered surfaces are jammed together when the pipe assembly is mounted to the easing 17 by the described action of the collar or coupling 19.

It can now be seen that fluid introduced to the bore 25 goes into the small pipe 5, while fluid introduced to the recess 18 goes through the holes 12 in the flange 11 of the sleeve 10 and into the space between the small pipe and the large pipe 6. Everything can be easily dismounted for cleaning or for replacing the parts, and fluid-tightness is easily established on reassembly of the parts. Furthermore, all of the parts that have been described may be easily manufactured. The combined assembly has extremely good mechanical strength which is important in the case of an extension gun.

The back end of the handle-like valve casing 17 has two threaded inlets equipped with hose couplings 28 and 29. These two inlets respectively lead through ducts 30 and 31 to laterally spaced and mutually parallel bores 32 and 33 respectively. These bores are formed transversely and completely through the casing 17 so they extend between what is normally the top or bottom of the handle provided by this casing. The top portions of these bores 32 and 33 are counterbored to provide enlarged portions 34 and 35 respectively.

The two bores 32 and 33 are threaded adjacent to their junction with their counterbored upper portions, and externally threaded valve seats 36 are screwed into the respective bores. Each valve seat 36 has an outwardly extending top shoulder or external flange 37 that fits against the shoulder naturally formed at the junction of the bores 32 and 33 with their respective counterbores 34 and 35.

It is now possible to emphasize an important feature of this valve assembly. The valve seats 36 are made exactly alike and are completely interchangeable as are all the fluid-controlling valve parts described hereinbelow. The corresponding parts of each valves assembly are, for this reason, all given the same numbers hereinbelow, as has just been done for the valve seats 36. Heretofore, the prior art has been unable to make the necessary two valves of a spray gun, so that the valve parts of the respective valves are completely interchangeable. This interchangeability has, of course, great advantages from the manufacturing standpoint and respecting the sellers of the gun who must stock replacement parts. It is also important to the operator or user of the gun because he needs to maintain only a single set of replacement valve parts, and when he goes to assemble the parts it is impossible for him to get the different valve parts confused between different valves.

This feature permitting this interchangeabality of parts is particularly clearly illustrated by Fig. 2. This feature is obtained by making one of the counterbores 34 and 35 deeper or longer than the other. In Fig. 2, the broken line XX shows the approximate level to which the counterbore 35 is sunk. It is apparent that the counterbore 34 is not sunk so deeply. Thus, the shoulders at the bottoms of the counterbores 34 and 35 are relatively offset vertically. Therefore, when the two identical valve seats 36 are screwed into the respective bores 32 and 33, the valve seat in the bore 32 automatically comes to rest at a higher level than does its mate when it is screwed into the bore 33. This different leveling or offsetting, thus effected by the diiferent counterbore depths, permits all of the working parts of the valves to be made exactly alike in the form of mates or duplicates.

'With the above understood, the balance of the valve assembly parts include, in each instance, a poppet valve 38 made to fit the valve seat 36 and having a stem 39 extending downwardly through the bore 32 or 33 and projecting from the bottom of the valve casing 17. The stem passes through a compression packing seal assembly 40 screwed into the bottom end of the bore 32. The counterbore 34 or 35 is sealed at its top by a screw cap 41. A helical compression spring 42 surrounds the projection of the stem 30 and works between the seal assembly 40 and an enlarged head 43 formed on the outermost end of the stem 39. The packing nut of the seal assembly extends well outside of the casing 17.

With the two ducts 30 and 31 opening into the counterbores 34 and 35, respectively, fluid is admitted to the lower bore portions 32 and 33 whenever the poppet valves are lifted from their seats 36 by pushing up on the enlarged ends of the stems 39. This permits the fluid to flow through the seats and into the bores 32 and 33. Since the bore 32 connects through a duct 44 with the bore 25, fluid admitted to that bore 32 goes through the small pipe 5. The other bore 33 connects through a duct 45 to the recess 18 and, therefore, it connects to the space between the two pipes of the pipe assembly.

With the identical valve seats 36 positioned at different levels, or relatively offset, if the valve stems are provided with a common operator the valves are sequentially operated as is ordinarily required for spray gun operation. In the illustrated gun, the left-hand valve assembly in Fig. 2 controls the air and has the valve seat 36 at the lower position. Therefore, actuation by a commonactuator opens this valve first, the valve in the bore 32 then opening later. The closing action is in the same order, the valve in the bore 32 closing first with closing of the valve in the bore 33 following. The valve in the bore 33 controls the atomizing fluid, usually air, so the atomizing fluid is turned on first and off last, as compared to the control of the valve controlling the atomized fluid.

A common actuator for the two valves is provided by a lever pivoted by a bolt 46. The lever, adjacent to this bolt, has the form of a box section 47 with an open face facing the valve casing 17 and enclosing and protecting the two valve stems 42, the projection portions of the valve stem sealing assemblies 40 and practically everthing relating to the valve construction that might be damaged by rough usage. The bolt 46 fastens this section to the valve casing 17, and the balance of the lever extends backwardly along the handle or valve casing 17 in the form of a smooth, conveniently grasped portion 48. The entire lever including its portions 47 and 48 is an integral piece. Since the valve stems 39 project through what has been considered the bottom of the casing 17, and since the bolt 46 must therefore fasten the valve actuating lever or trigger to the handle bottom, the portion 48 is located for convenient use.

With this actuator or trigger, lifting of the lever portion 48 causes the outer wall of the box section 47 to first engage the lowermost one of the valve stem bottoms 43 and lift it before the other valve stem is engaged. Release occurs, of course, in the reverse manner.

The sealing assemblies 40 have not been described in detail because they may comprise conventional arrangement, the one shown being of usual type. It is to be emphasized, however, that each valve is made of parts that are exactly like the corresponding parts of the other valve, this being possible because of the dilferent depths the counterbores 34 and 35 are formed, whereby to automatically bring the valve seats 36 to difierent levels, when the seats are installed, even though these seats are identical. Since identical parts are used, there is no chance for an inexperienced person to get the valve parts mixed and confused and installed in the wrong places. The manufacturing and servicing advantages have already been mentioned.

I claim:

A spray gun subcornbination including telescoped small and large pipes, a member at one end of said telescoped pipes and which provides corresponding small and large connections for the ends of said pipes, means for anchoring said small pipe against pulling from its said connection and means for anchoring said large pipe against pushing ahead of its said connection, the opposite end of said small pipe being externally threaded and the opposite end of said large pipe being cylindrical, a sleeve fitting over said cylindrical end of said large pipe and having an internal flange engaging the edge of said end and providing an internally threaded hole surrounding said threaded end of said small pipe, and an internally and externally threaded bushing screwed into said hole and onto said threaded end surrounded thereby, said flange being axially perforated for fluid flow therethrough.

References Cited in the file of this patent UNITED STATES PATENTS Layne Jan. 26, McDuflie Jan. 25, Shonnard Oct. 4, Binks Nov. 29, Albers Dec. 15, Ross May 1, Roach July 17, Jenkins Nov. 27, Brown Dec. 12, Pick Apr. 29, Sturman Mar. 17,

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