US2029408A - Powder-spraying appliance - Google Patents

Description

A Feb. 4, 1936.

4s. BRAMSEN E1' AL POWDER SPRAYING APPLIANCE Filed June 29, 1933 3 Sheets-Sheet 1 Fb. 4, 1936. s. BRAMSEN Er A'. 2,029,408

Feb. 4, i936..

s. BRAMsEN Er A1.

POWDER SPRAYING APPLIANCE Filed June 29, 1935 3 Sheets-Sheet 3 q e WM :C PIJ n. e QW .cle l@ MIMI.. ir

Patented Feb. 4, 1936 UNITED STATES PATENT OFFICE POWDER-SPRAYING APPLIANCE Delaware Application June 29, 1933, Serial No. 678,220

17 Claims.

Our invention relates to a pneumatically actuated appliance forcing powdered or otherwise comminuted dry materials out of a container and thereafter projecting this material in the form of an effectively directed spray against a surface which is to be coated with a layer of such material.

. In one of its general objects, our invention aims to simplify the procedure required fo'r applying a dry and finely subdivided material to a surface and of greatly simplifying and cheapening the needed apparatus, in comparison with the procedure and apparatus heretofore employed for such purposes. Furthermore, our invention aims to provide a simple, light and easily portable container and spray device assembly for the above purpose which can readily be adjusted according to the nature of the material, and which will also permit the projected spray to be easily varied 20 from a circular cross-section to that of a flattened or sheet-like spray.

In using small particles of material as constituents of a coating which is adhesively attached to a surface, it has heretofore been customary 25 (on a large manufacturing scale) to drop such particles of material loosely upon a substantially horizontal surface after applying a thin layer of an adhesive liquid (such as a varnish or glue) to .that surface, and to brush or shake olf the surplus 30 of material later on. With soft materials, such a brushing usually roughens part of the surface, so that the coating may need to be rolled or pressed down later to secure a uniform appearance; and for many purposes it is necessary to pass the ma- 35 terial through an oscillating sievefor securing the desired distribution of its particles, thereby also requiring an additional operation and a correspondingly complicated equipment.

'Moreovelg dry material cannot readily be dis- 40 tributed with any degree of uniformity over interior surfaces of an object, as for example upon the inner faces or sides of a suit-case, violin case or the like'. And a subsequent smoothing of the coating is not readily feasible upon surfaces which 45 are not flat, nor can any such additional smoothing operation be employed when the coating is to have a roughened or pebbled appearance.

Another procedure which has also been employed with many materials consists in simul- 50 taneously projecting both particles of the material and an adhesive against the surface. This procedure either requires two separate projecting nozzles with a separate supply of air to each, or else requires some arranging for intermingling the L 55 material with the adhesive either before the joint projection of both thereof or otherwise before both the material particles and the adhesive reach the surface. In either case, these particles of material then are coated (either partly or entirely) with adhesive, so that the resulting coat,- ing has a more or less glossy appearance which is undesirable for many purposes, and the amount of adhesive is far greater than the quantity actually needed for causing the particles of material to adhere to each other and to the surface which 10 is to be coated.

Our present invention above recited objections cedures and apparatus by providing means whereby compressed air will rst loosen and separate particles of dry material within a container, and thereafter will forcibly project these particles in generally non-contiguous relation to each other and inthe form of a spray of suflicient concentration for effective direction against the surface which is to be coated; and whereby the pressure of the air projected along with these particles will also press such particles firmly against a still liquid adhesive layer on the said surface and will expedite the drying of the adhesive. i

More particularly, our invention aims to provide a material-spraying appliance for this purpose constructed so as to constitute a cover for a receptacle containing the material, and aims to provide an appliance construction which will be exceedingly simple, inexpensive, non-clogging,

aims to overcome the to the previous proand easily manipulated. In addition, our invention aims to provide means whereby such an appliance can readily be adjusted for eficient use with materials of widely varying specific gravity and compressibility, and aims to provide an easily cleaned appliance which can readily be manipulated as a unit by a single hand of the user.

Illustrative of our invention andv of more detailed objects of the same, Y

Fig. 1 is a vertical and generally diametric section through an embodiment of our invention in which the container is of the so called Mason jar type, and which includes convenient means for adjusting the proportion of the ejected material to the air projected with this material.

Figs. 2 and 3 are fragmentaryfront and side elevations, respectively, of the part of our appliance attached to the body of the jar or receptacle.

Fig. 4 is a fragmentary plan view of the cast body of the part of our appliance attached to the jar body to serve as a cover.

Fig. 5 is an enlarged axial section through the 55 body of the main aircontrol valve, taken along `the line 5--5 of Fig. 1.

Fig. 6 is a section similar to the upper portion of Fig. 4, showing a. simplified form having no means for varying the proportion of the ejected air to that of the projected material.

Fig. 7 is a. fragmentary bottom view of the main portion of the receptacle-cover and adjacent parts of Fig. 6.

Fig. 8 is an enlarged section taken along the line 6-8 of Fig. 6.

Fig. 9 is a fragmentary central, vertical and longitudinal section through the cast body of the same appliance, taken along the 'line 9--9 of Fig. '7.

Fig. 1U is a section allied to an upper portion ofFig. 1, showing our spray appliance as fur- Fig. 12 is an enlarged horizontal section, taken along the line I2--I2 of Fig. 10.

Generally speaking, we accomplish the objects n the jar' axis A, the resulting agitation will move of our invention by providing a generally closed and normally upright receptacle for the material; by admitting a jet of compressed air into this container in such a direction as to agitate, whirl and lift the material; by also blowing another jet of air across and above the mouth vof the receptacle toward an outlet nozzle to suck the mixture of air and air-separated material toward the said nozzle; by forming the cover of the cointainer so as to cooperate in guiding the material toward the said nozzle; and by providing control valves which can easily be manipulated by the user.

In the triple valve form shown in Figs. 1 to 4, designed for projecting thetmaterial in a conical mass spray, the receptacle I is a glass jar having the usual exterior thread T on its mouth portion. this jar being preferably of glass so that both the amount of material in the jar and the movement lof the material in the jar can readily be seen.

Screwed' upon the mouth end of this jar and normally sealed to it by a compressible gasket 2 is a cast body which includes a cover 3, a tubular shank 4`extending rearwardly from this cover, and a hollow handle 5 depending from the outer -end of the shank 4.

The cover 3 has at its forward edge an interiorly threaded bore 6 in axial alinement with the bore 4A of the tubular shank 4, into which bore Aa projecting nozzle or outlet nozzle 1 is screwed,

-pressed air is supplied to the lower end of the handle bore through an air hose H connected to the handle by a nipple 9, the passage of air from the handle bore to the shank bore 4A being controlled by an air valve including a nger-piece F which can be manipulated by a finger of the hand grasping the handle. v

Extending downwardly into thev cover 3 is a valve bore I0 which crosses the bore 4A so as to present a downwardly closed valve bore portion IDA below the said bore 4A for receiving the tip of an air valve II threaded into the said valve bore I0.

The bore 4A is further crossed behind the said ltal bore 4A to this tube I3 being controlled by 5 f a second valve I4. This tube I3 has its downwardly directed outlet at a considerable distance rearwardly from the axis A of the glass jar, and

also desirably has its lower portion upright, thereby permitting it todirect a jet of air downwardly in an approximately vertical direction. Moreover, we dispose the tube I3 with its lower end above the midheight of the receptacle, so that its discharge end is entirely above the material when the receptacle is not more than half lled l5 with material. This we do for the reason that initially closely packed material would unduly reduce the agitating and lifting action of the air issuing from this tube if the tube extended down into the material. When all three of the valves are at least partl open, part of the compressed air flowing forwardly through the air passage 4A issues downwardly into the jar so as to loosen and agitate any finely divided material M in the jar. With 25 this air directed in a jet J considerably behind the material largely in the general direction of the dotted line D in Fig. 1, namely forwardly-in the lower portion of the jar and thereafter upwardly. At the same/time, a blast of air will also issue forwardly from the air nozzle I6 and through the bore 8a of the-discharge nozzle to blow material which is in frontof the former nozzle through the latter nozzle-and to project this 35 material forcibly through the latter nozzle in a concentrated stream coaxial with the latter nozzle. In addition, the air issuing from the air nozzle I6 also acts (after the manner of fiuid issuing from the inner tube of an injector) for sucking 40 the mixture of air and material out of the entire Yupper portion of the receptacle, and for preventing the lifted material from collecting in or Y near the outlet bore.

To facilitate the directing of the agitated and aerated material toward the discharge nozzle, we form the cover 3 so that its lower face is generally"dome-shaped, with the highest point of the dome between the'rear end of the discharge nozzle 8 and the vertical axis A of the jar. Then we also have this lower face of the cap slope downward rearwardly (at opposite sides of the air nozzle I6 and of the cap part 3B into which this air nozzle is threaded) approximately to the level of the mouth end of the jar, as shown by the dotted line I5 in Fig. 1, thereby enabling the said suction to act eiectively also on material which has been forced upwardly in the rearward portion of the jar, so as to guide the lifted material to the discharge nozzle.

To obtain both an elcient suction and a forcible projection of the material after the latter is ejected through the dischargeinozzle, we eifectively elongate the horizontal air duct 4A by screwing into the cover (in axial alinement with` thisV duct) an air nozzle I6 which has a contracted outlet, and which has the discharge end of this outlet disposed forwardly of the /vertical axis of the receptacle. Then we also provide an ample spacing between the lrip of the air nozzle I6 and the rearward portion 8B of the bore of the discharge nozzle, so that the commingled air and material can flow freely through the discharge 170113.)10 aid in this While Still permitting the forward-portion 8A of the bore of the discharge 75 nozzle to project the air and material in the form of a fairly concentrated spray I1, we desirably form this forward bore portion approximately cylindrical and make the rearward'bore portion 8B of a decided forward taper.

As here shown, the main air valve comprises a tubular valve body I1 (Fig. '5) threaded axially into the upper end of the tubular handle and having an annular shoulder I8 seated on a corhas a closure element 22 fastened to its lower end and which has at its upper end the finger-piece F, a compression spring 23 being interposed between this ilnger-piece and the valve body for continually urging the just described main'valve member upwardly to its closure position.

' With our appliance thus constructed, and with both of the valve cocks II and I4 partly opened,

`the user can readily see experimentally (when the main valve is also opened) how vfar the'material is ejected from the container and to what degree this material is' distributed by the air. Then he can readily adjust one or both of the valve membersv II and I4 according to the specinc gravity of the material, the nature of the material and the proportionate aeration desired. And, since the entire supply of air is controlled by the spring resisted main valve, this adjustment remains undisturbed whenever the spraying of the material is halted.

In practice, the providing of two separate ad- `justments for the supply of agitating and lifting air to the receptacle, and for the control of the air jet issuing from the air nozzle I6, is important for two reasons: One is the difference in the amount of air required for agitating the material, which varies with the nature of the material, and another is the difference in the relative proportions of the emitted air to the ejected material, which may vary both with the material and with the purpose for which the appliance is used. For example, the difference in the specific gravity between finely ground wool or rayon and vitreous enamel is enormous, thereby requiring re1- atively much more air for properly agitating the heavier vitreous material within the receptacle.

So also, the relative amount of air emitted from one appliance needs to be adjusted -for eflilentirely overcomes this difiiculty and enables manufacturers of such. signs to apply the vitreous enamel 'with a simple spray device instead of using a sifting operation which is less economical in practice.

, On the other hand, when a sheet of cloth or paper is to be coated with a thin layer of socalled ilock" (meaning finely ground wool, cotton or rayon), this can speedily be done by spraying such ilock upon the sheet while the sheet is coated with still'sticky varnish, then as soon as the entire surface ofthe sheet is covered with the ock, the air valve I4 can be closed, thereby permitting air alone to issue from the appliance for expediting the hardening of the coating.

However, when the coating material is of such a nature that the particles will not readily pack or jam in the discharge outlet, the forward valve I I can be keptclosed during the spraying, thereby enabling the air admitted to the receptacle to eiect the entire ejection of the material in the form of a less concentrated mass spray andto a shorter distance from the appliance.

Since the body member of our appliance can be of aluminum, our entire appliance (including the receptacle) can readily be made suiiiciently light so as to be manipulated by a user grasping the handle with one hand, and. a mere unscrewing of the receptacle permits instant access to its interior for refilling. Moreover, itwill be obvious that all parts can readily be detached and cleaned when this becomes necessary.

However, while we have heretofore described our solid-material spraying appliance having two separate controls in addition to a main air control valve, we do not wish to be limited in this respect. Nor do We wish to be limited to the above described details of construction and arrangement, since many changes might be made without departing either from the spirit of our in vention or from the appended claims.

For example, if our appliance is to be used only in connection with materials which do not require a relatively large amount of air for agitating, lifting and ejecting thefmaterial, the previously described valve for controlling the part of the air supply which is emitted through the air nozzle I6 can be omitted, as shown in the more simple embodiment of Figs. 6 to 9. In this cheaper type, the upright bore into which 'the valve member II (which controls the air ejected into the receptacle) has its axis offset laterally from that of the air duct 4A, and the upright bore is continued downward entirely through the cover by a smaller diametered bore 24 through which a portion of the air enters the interior of the receptacle I.

On the other hand, we have found that for some purposes our appliance can be used more advantageously if designed for projecting the material in a mass spray which ,is attened in cross-section, and 'we have also found that the extent of this spray-shape flattening (which may vary from an ellipse to an almost rectangular section) may need to be varied according to the nature of the material which is being sprayed. To meet these requirements', we also provide an auxiliary air-passage in the container-cap portion of the body member of our appliance, provide an outlet nozzle having forwardly converging air discharge ports at opposite sides of a common outlet for the material and air issuing from the container, and provide separate means for controlling the supply` of air through the said auxiliary air-passage to the said discharge ports.

Thus, Fig. 10 shows the cap 3A of our appli- 1 ance as provided, in addition to the air inlet passage 4B which leads to the air nozzle I6, with an auxiliary air-passage 30 opening into an annular groove 3| formed in the forwardly facing edge of the cap which has the outlet bore 6A. This outlet bore 6A is cylindrical and unthreaded `and slidably receives the shank 32 of an 'outlet nozzle which has its forward portion formed (after the manner of the air nozzles in vspray guns) with two diametrically opposite and forwardly extending projections 33.

Each of these projections has an elbow-shaped air .passage extending through it, withy the rearward portion 34 of the passage open to the groove 3| and the forward portions 34A converging forwardly toward each other.

Then we provide an upright valve member 35 controlling a port 36 which connects the main air passage 4B with the auxiliary air passage 30, and dispose the other two adjustment-control valve members Il and4 I4 as employed for the same purposes in the embodiment of fFig. 1, as shown in Fig. 10 which gure has the port 24 indicated in dotted lines. 1 Thus arranged, 'the valve member I4 controls the flow of air'through the downwardly leading passage` 24 to the interior of the container, and the valve member I5 controls the supply of air to the "air nozzle I6.

With this four-valve form ofgur appliancel (which would also include agmain air control valve 22v as shown in Fig. 1), the' forwardly tapering inner portion 8B and the discharge portion 8A of the outlet for the discharge of the mixture of air and material can be the same as shown in Fig. 1; and when the valve 35 is closed, the material is discharged in the form of an aerated conical mass spray.

However, when the valve 35 is also opened, the supplemental air jets issuing from the ports 34A will flatten the projected spray so as to change the cross-section of the spray to that of an ellipsis havingI its major axis at right angles to the common plane of the axes'of the forwardly lconverging supplemental air jets. By varying the extent to which the supplemental air-control valve 35 is opened, we can correspondingly vary major' axis in a horizontal. plane diametric of the axis A of the said discharge nozzle, but for some purposes it may be more advantageous to have the discharge spray attened along an upright plane so as to be projected substantially in the form of an upright sheet which will move laterally over an upright surface when the operator passes the appliance horizontally in front of this surface. v

To permit this, we desirably construct the discharge nozzle so that its (rearward) unthreaded shank sockets slidably in the cap bore 6A, and so that this nozzle presents a flat annular rear face bearing flatwise against the adjacent part of the frontal cap portion of the body member of our appliance, and clamp this discharge nozzle 'to the body member by a clamping ring 4318 as of air to the interior of the container and to the air nozzle I6, and the upright valve 35 controls the air supply to the groove 3I`and'from this groove to the ports 34A fromwhich the spray-ilattening air jets issue. With the upright valve 35 closed, this type of our appliance operates in the same manner as the previously described two tening the emitted spray to any desired extent.

By making the groove 3l of a cross-section many times greater than that of thelauxiliary air passage 30,l we permit the air pressure to equalize throughout the interior of this groove, thereby obtaining air jets of equal velocity and volume from both of the supplemental air ports 34A.

By arranging the outlet nozzle so that it can -easily be rotated when the clamping ring 38 is slightly loosened, we enable our appliance, when held substantially upright by the user, to project the material in a spray iiattened along any desired plane diametric of the axis A-of that outlet nozzle, so that the embodiment of Figs. 10 to 12 readily lends itself to the projecting of an enormous variety of finely divided solid'materialsas for example, paper scraps for filling hollow walls to deaden sound, sawdust `for producing a rough nish on a wall coated with a still wet varnishvor other adhesive material, sugar for coating cakes, or textile ock for coating book covers or caskets. f

With each of the illustrated embodiments, the air nozzle I6 desirably has a polygonal enlargement I6B intermediate of its length, for engagement by'a wrench when assemblying the appliance. This also enables the user to vary the spacing of the tip of the air nozzle from the discharge bore 8A, so as to eiect an adjustment vof the concentration of the ejected conical mass spray, and a similar adjustment might be made with the air nozzle in the triple-valve spray device of Fig. 1.

`So also, the distance towhich the air pipe I3 extends downwardly into the receptacle in Fig. 1 may be varied, and even the position of the outlet of this pipe with respect to the axis ofthe receptacle. However, we have found our appliance to operate most efllciently when the air is admitted to the receptacle considerably rearward of the receptacle axis (when the discharge outlet is at the front) and so asto emit the air approximately vertically downward. Then whenthe appliance is in use, some of the material will also be swirled upwards along (or near) most of the riser side portions of the receptacle in addition to the material following the general direction of the dotted line J in Fig. 1, as for example along the dotted line 26. Consequently, the entire dome-like lower face-of the cover 3 excepting that underhanging the nozzle-receiving portion 3B redirects the air-lifted material toward the entrance portion 8B of the discharge outlet, thereby substantially equalizing the distribution of the material and air in the discharged mixture.

In both of the illustrated embodiments of our invention, the compressed air which isdirected downwardly into the receptacle issues from an outlet disposed above the midheight of the receptacle-or above the material when the receptacle is not more than half filled initially-serves primarily for agitating and lifting the upper portion of the material, while the forcible projecting of the lifted material out of the receptacle is effected by the air which issues from the air nozzle I6 and which is directed coaxially with the outlet nozzle 8. Moreover, by forming the cover of the receptacle so that it arches freely above the forward portion of the air nozzle I6, we permit the particles of material to be lifted freely above and alongside this forward air nozzle portion, as well as in front of the said nozzle, and we utilize the suction effect of the air issuing from the air nozzle I6 for directing the lifted material into the discharge nozzle 8. f

Consequently, our invention avoids the following five difficulties encountered in attempts at using heretofore proposed pneumatic appliances for spraying nely divided materials:

(1) The substantial choking of the downwardly directed air duct which occurs when this-duct opens near the bottom of the receptacle, so that the outlet end of this duct is imbedded in the material unless the receptacle is almost empty.

(2) The impossibility of projecting the material either for any substantial distance or in a well concentrated stream, which occurs when the appliance is so constructed that the material is discharged only by the residual force left in the air after this air has agitatedand lifted the material.

(3) The reducing of the Adischarge velocity of the ejected material, which -occurs when the downwardly issuing air is directed against the inner face of a riser wall of the receptacle (instead of being directed toward the bottom of the receptacle as in our here presented appliance) so that this air is reduced in velocity before it reaches the material.

(4) The reduction in the concentration of the effected discharge'of material which occurs when theair nozzle which opens toward the material discharge outlet at the front of the appliance has its outlet rearward of the vertical axis of the receptacle, or has this outlet out of alinement with the said material discharge outlet.

(5) A lack of uniformity as to the distribution of the material in the projected spray.

Moreover, while we have illustrated our invention in the form of light and portable appliances, we do not wish to be limited in this respect. Indeed, even with a relatively small form of our appliance including anat-bottomed receptacle, we desirably provide the cover with an upwardly directed hook 25 (as in Figs. l, 2 and 3) so that this appliance can be suspended by a cord or the like which will then support the weight of `the entire appliance while permitting the user to vary the direction of emitted spray.

We claim as our invention:

1. A pneumatic appliance for spraying comminuted solid materials, comprising an upright receptacle; a'detachable cover normally sealed to the mouth of the receptacle, the cover having a horizontal bore at its forward edge and above wardly downward and substantially merging with the rear end of the bore of the discharge nozzle; the cover having a horizontal air passage extending through the rearward portion coaxial' with the said nozzle,v the said passage having its forward end open and freely spaced rearwardly from both the discharge'nozzle and freely underhanging the cover and disposed forwardly of the axis of the receptacle; the cover also having a port leading vdownwardly from the said passage behind the said receptacle axisy and opening into the receptacle; and means for supplying compressed air to the` rear end of the said passage; the air duct having its'forward end spaced rearwardly from the said nozzle and farther forward than the said highest portion of the dome-shaped lower face of the cover.

2.y An appliance for Vspraying finely divided solid material, comprising an upright container for the material, the container having a lateral discharge outlet adjacent its forward upper edge;

' means for projecting an initially cylindrical jet of compressed air downwardly and in an approximately vertical direction into the container with the axis of the jet spaced rearwardly from the axis of the container, and with the discharge of the said jet starting above the midheight of the container whereby the said air jet agitates the material and lifts the material, means for projecting a second jet of air across the upper portion of the container coaxial with the said opening, and adjustable means for proportioning the air supply to the said two projecting means,-the second a-ir projecting means including an air nozzle threaded into the cover and having its outlet disposed forwardly of the vertical axis of the receptacle and spaced rearwardly from the discharge outlet of the container, the said air nozzle being freely spaced downwardly from the top of the container.

3. A pneumatic appliance for spraying comminuted dry material housed by an upright receptacle, comprising a receptacle cover provided at its forward edge with an aperture and having an annular groove in the said forward edge concentric with the said aperture; the cover also having a main air duct extending forwardly into it and'presenting its discharge end coaxial with and spaced rearwardly from the said apertured cover edge, an air port leading downwardly from the main air duct and opening into the container, and an auxiliary air passage leading to the said groove from a part of the main air duct rearwardly of the connection of that duct tothe said downwardly leading air port; an air nozzle mounted on the cover and provided with a cen- -tral air discharge port alining with the said aperture' and with a supplemental air port leading forwardly from the said groove; and separately adjustable valves respectively controlling the supply of air from the main air duct to the said downwardly leading air port, the discharge end of the main air duct, and the auxiliary air passage.

4. A pneumatic appliance for spraying comminuted dry material, comprising an upright receptacle housing the material, a receptacle cover provided at its forward edge with an outlet bore above the mouth of the receptacle, means supported by the cover and freely spaced rearwardly from the rear end of the said outlet for projecting air forwardly and coaxial with the said outlet bore in a jet freely spaced downwardly from the forward portion of the cover and thereafter axially through the outlet to produce a suction from the upper portion of the receptacle the receptacle, the said dome-shaped face sloping through the outlet; means for projecting air downwardly into the receptacle from a point lower than axis of the said outlet and above the midheight of the receptacle, so as to agitate material and air within the receptacle, means for supplying compressed air to both ofthe said air-projecting means, and adjustable means for proportigning the`amount of air supplied to the `of the said face slopes downward and into merging relation to the rear end of the said outlet for guiding material from the uppermost portion of the receptacle outlet.

6. A pneumatic appliance for spraying dry comminuted material, comprising an upright receptacle housing the material; a cover member iitted upon the mouth end of the receptacle and provided at its forward edgewith a discharge bore; the cover member having an air passage extending into it and presenting its outlet portion coaxial with the said discharge bore and spaced rearwardly from the rear end of the said discharge bore; the diameter of the outlei'l end of the said air passage being a minor fraction of the diameter of the rear end of the discharge bore; the cover member also being provided with a second air passage for projecting air downwardly into the-receptacle in a iet of smaller diameter than the rear end of the said discharge bore.

7. A pneumatic material spraying appliance as per claim 6, in which the rearward portion of Athe lower face of the cover member is formed for forwardly deecting toward the said outlet the material lifted in the receptacle through the action of the air projectedrfrom the said second air passage, and for permitting the lifted material to ow around the air issuing from the lrst named air passage.

8. A pneumatic material spraying appliance per claim 6, 'including valve means on the cover member for proportioning. the amount of air projected respectively from the said air passage and from the said air duct.

9.v A pneumatic appliance for' spraying comminuted dry material, comprising an upright receptacle housing the material, a receptacle cover t provided at its forward edge with an outlet bore above the mouth ofthe receptacle; the cover also being provided with an air passage having its outlet portion underhanging andfreely spaced downwardly from a forward portion of the cover, the outlet portion of the said passage. being coaxial with and spaced rearwardly from the said outlet fbore and being of smaller diameter than the rear 1 1. A spray gun for fibrous material including a receptacle having a relatively large open neck,

a gun body mounted on said neck overlying the opening of said receptacle, said gun body having a main" air passage adapted to communicate with a source of air pressure, means closing said pas- 10 sage manually operable to open the same, said gun body having an orice communicating with said main air passage and having its discharge directed into said receptacle for agitating said material, means to regulate the air flow in said i5' oriflce, a' spray head carried by said gun body having a central nozzle opening with a forwardly convergent surface providing a discharge throat, and oppositely disposed side openings, s'aid main air passage being oflesser diameter than said 20 discharge throat, said gun body having an auxiliary air passage communicating with said main air passage and said side openings whereby the stream of fibrous material passing from said nozzle opening isfcaused to be divergent in a 25 single plane and means to regulate the flow of air through said side openings.

12. Arpneumatic appliance for spraying comminuted dry material, comprising an upright reA ceptacle housing the material, a receptacle cover 80 provided at its forward edge with an outlet bore above the mouth of the receptacle; the cover also being provided with an air passage having its outlet portion underhanging and freely spaced downwardly from a forward portion of the cover, ,35 the outlet portion. of the said passage being coaxial with and spaced rearwardly from the said outlet bore and being of smallerydiameter than the rear end of the said outlet bore; and an air tube supported by the cover and communicating 4o with said air passage and disposed for directing air downwardly against material in the receptacle.

13. A pneumatic appliance for spraying dry comminuted material, comprising an upright receptacle housing the material; a cover member 5 tted upon the mouth end of the receptacle and having a lateral aperture; a material discharge nozzle fitted upon and detachable from the apertured portion of the cover member, the cover member having a main air passage extending into 150` it; and an air projecting nozzle detachably fastened to the cover member and connected to the main air passage and coaxial with the said discharge nozzle, the discharge end of the air projecting nozzle being freely spaced from the bore 65 of the discharge nozzle; the cover member also having a supplemental air passage disposed for projecting air downward into the receptacle to agitate and lift material within the receptacle, and the cover member having a downward face 60 portion thereof spaced upwardly from the air projecting nozzle and from the inlet end of the bore of the discharge nozzle to permit both air and lifted material to pass alongside and above. the air projecting nozzle. 65

14. A pneumatic appliance as per claim 13, in

in which the said downward face portion of the cover issubstantially dome-shaped and merges with'the inlet end of the said aperture.

15. A pneumatic appliance as per claim 13'. in- 70 16. A pneumatic appliance for spraying dry comminuted material, comprising an upright receptacle housing the material; a cover member iitted upon the mouth en d of the receptacle and having a lateral aperture; a material discharge nozzle tted upon and detachable from the apertured portion of the cover member, the cover member having a main air passage extending into it; an air projecting nozzle detachably fastened to the cover member and connected to the main air passage and coaxial'with the said discharge nozzle, the discharge' end of the air projecting nozzle being freely spaced from the bore of the discharge nozzle; the cover member also having a supplemental air passage disposed for projecting air downward into the receptacle to agitate and lift material within the receptacle; an exterior -air nozzle associated with the material nozzle,

the cover having a third air passage leading to the said exterior nozzle, and the exterior air nozzle having outlet ports for projecting forwardly converging air jets against the stream of material and air issuing from the material nozzle. 17. A-pneumatic appliance as per claim 16, in which the supplemental air passage and the third air passage both lead from a part of the main air passage rearward of the connection of the latter to the air projecting nozzle; the appliance also including separate valves 'for controlling the flow of air through the supplemental air passage, and for controlling the supply of air to the said outlet ports of the air nozzle.

SVEND BRAMSEN. ERIC GUSTAFSSON. FRITZ WAHLIN.

Images