US2734776A

US2734776A - elliott

Info

Publication number: US2734776A
Authority: US
Publication date: 1956-02-14
Anticipated expiration: 1973-02-14

Description

Feb. 14, 1956 c. H. ELLIOTT BLOW-GUN Filed Feb. 6, 1953 INVENTOR. Char/es E/hoff ATTORNEY United. States. Patent BLOW -GUN GharIesHQElIiott, Houston, Tex., assig'nor to Reed Roller Bit -Comp'any, Houston, Tex., a-c'orporation ofTexasi ApplicationFebruary6,1953, Serial No. 335,540

1 'Clflilll'. (Cl."Z99 --149) This invention. relates to blow-guns, consisting essentially of a" hand" hel'dbbdy having-a passage extending therethroughponezendfofiwhichlis provided with a nozzle while the other is shaped to receive .anair hose, and containing. manually operated valve means for controlling discharge of compressed air through the nozzle for cleaning purposes.

This application is a continuation-in-part of the copending application Serial No. 283,779, filedApril 22, 1952.

One object of this invention is to provide such blowguns with improved valve means, of relative large capacity, readily operable for controlling the discharge of compressed air through the nozzle.

Another object of this invention is to provide such blow-guns with valve means comprising a plurality of standard pneumatic tire core valves each constituting a single unit easily installed in and removed from the gun.

Another object of this invention is to provide valve means for blow-guns comprising a plurality of valve units arranged and disposed in a manner affording a smooth throttling action through which the amount of air discharged through the nozzle can readily be controlled.

For better understanding of the present invention, reference may be had to the accompanying drawing in which:

Figure 1 is a longitudinal sectional view of a blow-gun embodying the invention.

Figure 2 is an enlarged cross sectional view taken on line 2-2 in Figure 1.

Figure 3 is an enlarged sectional view taken on line 33 in Figure 2, and

Figure 4 is a top view of the blow-gun.

Referring to the drawing, the blow-gun consists of a body made of any suitable metal such as aluminum, bronze, or cast iron, or of non-metallic material such as molded rubber, plastic and the like. It can be of any desired configuration, but preferably it comprises a hand grip portion 11 adapted to fit in the hand of the operator, and an outwardly tapered extension 12 projecting angularly therefrom and terminated by a removable nozzle 13. Toward its free end, the extension 12 is provided with an integral hook 15 through which the blow-gun may be hung at easy reach of the user.

The hand grip portion 11 has a central inlet bore 16 extending partway therein from the lower end thereof as seen in Figure l, where it is screw threaded as at 17 to receive the threaded end 18 of a conduit through which compressed air is supplied to the bore 16. Similarly provided in the upper end of the hand grip portion 11, there is a second fiat bottom bore 19 extending partway therein and defining, between its inner end and the inner end of the bore 16, a relatively thick partition or valve carrying wall 20. The second bore 19 is normally closed by a removable bushing 21 screwed therein, through which is slidable a plunger 22 formed with a relatively large fiat face inner head 23 and an outer head or knob 24.

Drilled through the wall on axes offset from but parallel to the center axis of the

bores

16 and 19 are 2,734,776 Batente'd Febs 14;:1-956 'ice,

several relatively small' orifices 25 normally afiording communication between' the

bores

16 and 19. Eaeh orh ficei has its-end adjacent the bore 19 serew threaded as at" 26 to receive a standard pneumatic tire core lvalve unit 27. This valve unit, which iswell"known' andImiversally obtainable, may briefly be described as "comprising a housing 28 threaded at one-end to fitin thethreads 26, and carryinga ring packing 29' affording'a fluid tight joint'witlr the wall of the orifice 255 This housing has a-cent'ralbore 30=extending therethrou'gh in which is'slid ablY-mduntedavalve stem 31 hav'ing a metal cu'p shaped rubber filled valve head- 32"rig'idly' secured thereon This valve head has its under side engaged by oneend' of 'a compressionspring 33 mounted-"on the-stem while the other end 'engages aspringseat 3'4 slidablon the'adjacent end'bf'thestem 31. The other'or free end of th'ewalve or valve stem 31 extends into the bore 19.

The extension 12 has a passage 35 extending' 'therethrouglr and connecting the bottom of'th'e here" 1910 the nozzle 13 Thi'spassagetogzther with'" bores lfi and 19 and orifices-25 constitute a-passageway havingth'e nozzle 13asits outlet end andthe threaded" end 17' of the bore IG as -its*- inletend. Interposed between the outlet I and inlet ends of this passageway are the valve units 27 which are normally closed, and therefore prevent the flow of compressed air through the passageway.

The valve units 27 may be installed in or removed from the wall 20 by simply removing the screwed in bushing 21, thereby leaving the valve units readily accessible for installation or removal.

An important feature of this invention is to mount the four valve units in the wall 20 in such a manner as to position the free ends of the stems 31, when the valves are closed, at different distances from the flat face of the inner head 23 of the operating plunger 22, to cause successive opening of the valves upon downward movement of the plunger 22. Since the valves are normally held in closed position by the air pressure acting on the underside of the valve heads 32, it will be understood that with the valves opening successively, the user can gradually open the passageway leading to the nozzle 13 without having to overcome the combined pressure of the four valves. In other words, the pressure required by the operator on the plunger 22 to open all four valves is the same as that required to open one valve. Furthermore, the amount of compressed air discharged through the nozzle 13 may be controlled by the operator within a range of one valve partly opened to all valves fully opened.

The extent of variation in the distance between the free ends of the valve stems 31 and the inner head 23 of the plunger 22 need not be very pronounced. Only a few thousandths of an inch difference between each valve stem is suflicient to assure successive opening of the valves. This may be accomplished by purposely threading the holes 25 to difierent depths, thereby causing the entire valve units 27 to be differently spaced from the operating plunger head 23. In practice, excellent results have been obtained by simply relying on various manufacturing tolerances. Tolerances such as variations in the length of the valve stems, depth of the threads in holes 25, the degree of tightness with which the valve housings 28 are screwed in the orifices 25 and others, have been found sufficient to position the valve stems 31 in different distances from the plunger head 23 and cause successive opening of the valves upon downward movement of the operating plunger 22.

From the foregoing, it will be understood that the invention provides for a very simple and inexpensive blowgun, wherein the often complicated valves heretofore used in such devices have been replaced by standard valves which are universally obtainable at relatively low cost and can be installed in or removed from the blowgun without any difficulty. It will further be understood that by providing a plurality of valves in the wall 20, it has been possible to greatly increase the air capacity of the blow-gun while retaining all the advantages incident to the use of standard pneumatic tire core valves.

It is also apparent that with the valve stems 31 projecting into the lower end of the bore 19 in diiferent spaced relationship with the inner end 23 of the plunger 22, upon downward movement of the plunger the valves will automatically open successively, thereby enabling all the valves to be opened Without undue resistance by the combined pressure of the compressed air urging the valves in closed position, and that this successive or gradual opening of the valves enables the user to readily control the amount of compressed air discharged through the nozzle 13.

The details of structure and arrangements of parts shown and described may be variously changed and modified without departing from the spirit and scope of the invention.

I claim:

A blow-gun comprising a single member formed with an extension integral therewith, a compressed air conveying passageway within said member including an inlet bore having compressed air supplied thereto, a second bore coaxial with said inlet bore, a detachable bushing closing the'outer end of said second bore, a plunger slidable through said bushing, an air passage through said extension having one end opening into said second bore, a nozzle at the other end of said passage, a wall between said bores integral with said member, a plurality of orifices through said wall affording communication between said bores, interchangeable valve assemblies in said orifices each bodily removable as a unit upon removal of said bushing, each valve assembly including a valve member normally closing its respective orifice and a valve stem protruding into said secondbore, said stems being substantially of equal lengths and adapted to be depressed by said plunger for causing said valve members to open said orifices, said valve assemblies being mounted in said orifices so that when said valve members close said orifices the free ends of said stems are diiierently spaced from said plunger to cause said valve members to open said orifices successively.

References Cited in the file of this patent UNITED STATES PATENTS 1,706,230 Hilger Mar. 19, 1929 2,177,544 Warner Oct. 24, 1939 2,233,395 Blanchard Mar. 4, 1941 2,281,604 Smith May 5, 1942 2,534,183 Shaft Dec. 12, 1950