US 2513417 A
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Description (OCR text may contain errors)
July 4, 1950 c. H. LINDSAY 2,513,417 7 AIRF'OAM NOZZLE Filed Feb. 5, 1.946
BY 7 w Patented July 4, 1950 AIRFOAM NOZZLE Charles H. Lindsay, Elmira, N. Y., assignor to American-La France-Foamite Corporation, Elmira, N. Y., a corporation of New York Application February 5, 1946, Serial No. 645,592
The invention relates to a, so-called airfoam nozzle, by which is meant a form of hand-held device adapted to mix and convert into airfoam appropriate ingredients supplied to it, and also to serve for discharging and directing the resulting airfoam. More particularly, the invention is concerned with such a nozzle of a form adapting it to be coupled to a supply of water under pressure and including means whereby suction created by the water stream serves to draw into the stream an airfoam liquid and whereby suction created by the resulting mixture in turn serves to draw in and incorporate with it sufficient air to convert the mixture: into airfoam.
The object of the invention is an improved nozzle of this general character, the various features of advantage being shown incorporated in preferred form, but by way of example only, in the accompanying drawings.
In these drawings, Fig. 1'; is a broken-out longitudinal section through the preferred form of nozzle; Fig. II is a section on. the line Il--II of Fig. I (with part of the background omitted for the sake of clearness) and Fig. III is a crosssection on the line IIIIII of Fig. I.
The nozzle illustrated consists of a cast body, generally designated 1, and a pipe section, generally designatedv 2,. the former serving as a supply unit by means. of which the ingredients are introduced, and the latter serving as a receiver within which the airfoam is formed and by which it is discharged.
The body I comprises an integrally formed tubular hub 3 encircled by a rim or sleeve portion 4, the two being united byan intervening spider 5. As shown, the rim overhangs the spider on both sides, The front face of the spider (meaning the right-hand side as viewed in Fig. I) is recessed, as at 6, andv the pipe section 2 telescoped into therecess. By making the recess of adequate depth to provide a substantial length of bearing for the pipe: section, the latter may be rigidly locked in position, abutting the spider face, by means of screws 1 extending radially in,-
wardly from the periphery of the rim and through the intervening. portion of the spider.
As shown more particularly in Fig. II, the spider apertures" 8, of which there are four in this instance, extend substantially from the hub toi the rim; and the diameter of the recess 6 and the pipe 5 section 2' are such that the latter intersects: the apertures. intermediate the hub and the rim- When the interior of the; pipesection is under suction (as: presently described) external air is thus; free to flow fromiront: to: rear of they spider 55 or. main; receiver 2.
in the outer portions of the apertures B, that is, between the pipe section and the rim; and air is likewise free to flow directly to the rear face of the spider and into the pipe section throughthe inner portions of the apertures 8, that is, between the pipe section and the hub. With this arrangement it is virtually impossible for anyone handling the nozzle inadvertently to block off the air supply and thereby interfere with'satisfactory foam formation within the nozzle. Without conscious attention the person handling the nozzle can grasp it as happens to be most convenient. If, by chance, his hand happens toobstruct the now of air into the nozzle directly from the exterior to the rear face of the spider, it is of no material consequence, because free air flow is still provided for from the front face of the spider between the rim and the nozzle as above described. Similarly, an adequate air supply by way of the direct or rear inlet is provided notwithstandingv inadvertent obstruction of the front air inlet. It will be understood that while the width of the rim is not critical, it should be such that even a heavily-gloved hand grasping it will not obstruct both inlets at the same time. It will also be recognized that by making the dual air inlet structure. an integral part of the body portion of the unit, as is preferred, an extremely rugged structure is provided. I r
The central bore of. the hub 3" is formed wit sections of two diameters. In this instance, the section of the bore which extends forwardly from about the center line of the spider to the front end of the hub is of substantially uniform diameter throughout; and the rear section of the bore is of a greater diameter and internally threaded to receive a water nozzle member 9. As illustrated, the member 9 is arranged to'projecta stream of water into the forward or receiver section of the bore so as to create suction in the space Ill surrounding the member 9-. C'ommuni'- eating with the space i0 is a radial inlet II incorporated in the enlarged spoke [2 of the spider and adapted for connection to a source of supply of airfoam. liquid.
From the rear end of the unit projects a. flange 13 on whichv is mounted a hose coupling collar M, a strainer l5 preferably being provided to -ex clude large particles of foreign matter from the unit. As will be observed, the flange l3 and the I collar l4 are so dimensioned and located as not to obstruct the: entryof air directly tothe rear face of the spider and thence: into the-pipe section Preferably, means are provided for spreading the emerging stream at a somewhat greater angle (and hence causing it to strike the receiver wall sooner) than would otherwise be the case, a
greater length of the receiver thereby being made available for the thorough incorporation of the I air with the liquid to form foam. In order to minimize interference with the flow of the stream emerging from the hub bore, such means may consist of a conical spreader l5 of the form commonly used in garden hose nozzles and positioned by means of four slender spokes l6 which are clamped against the front end of the hub by a nut member I1.
As illustrated, and as is preferred, the receiver 2 is of generally uniform diameter throughout the major portion of its length; but, unless otherwise controlled, they-emerging stream of airfoam is not of an ideal character from the standpoint of uniformity and range of discharge. It has been found that the stream is very much improved in both these respects by selectively controlling its velocity within and adjacent the outlet end of the receiver. in such manner that the entire stream throughout its cross-section travels at about the same speed. Left to its own devices, the stream exhibits substantial diiferences in velocity throughout its cross-section, it being materially slowed down at its skin or outer surface due to friction between it and the re- I ceiver wall. The core of the stream, on the other hand, is not so hindered and emerges at a higher velocity. The stream as a whole, after it has emerged, is thus less uniform or solid and its range is adversely affected, particularly when projected in a, strong breeze.
In general, the desired control is affected by perienced'by the skin of the stream.
To insure maximum range, the receiver is preferably provided with a short outlet tip r of a diameter slightly less than that of the receiver proper, the tip being coupled to the reof rubber or the like. Optimum conditions are found to obtain when the minimum area ofthe annular stream as it passes the baflle I8 is sub- I stantially equal to .the cross sectional area of the tip 20. While, of course, .the dimensionsof the parts are subject to variation as maybe convenient or preferred, it may be noted-that the proportions indicated by the following are productive of excellent results: diameter of main section of receiver, about 2 /2"; maximum diameter of paratus. the airfoam liquid is or may be conveniently mixed with the water stream at or near the water pump, so that the nozzle receives already-mixed airfoam liquid and water by way of the hose coupled to it by collar I4, the nozzle otherwise functioning just as described.
In the light of the foregoing specificdescription, for illustrative purposes only, of a preferred form of the invention and its principles, the following is claimed:
1. In an airfoam nozzle, the combination of a tubular hub constituting a receiver for water and foam-forming liquid, a concentric rim encircling the hub and spaced from and united therewith by a spider having apertures therein extending substantially from the hub to the rim, the said rim having forwardly and rearwardly projecting I portions overhanging the spider, a hose coupling ceiver by a tapered section 21'. As indicated,'the tip 20 may be provided with a protective rin 22 the tear drop bafile, about 1%"; diameter of outlet tip, about 2".
While the nozzle has been described primarily with reference to its use for so-called portable usually carried by the person handling the nozzle, it will be understood that it is equally adaptable for use in conjunction with motorized apoperation, in which the airfoam liquid supply is supported at the rear of the hub and spaced both from the rear face of the spider and from the rearwardly projecting rim portion, thereby permitting free flow of external air to the rear face of the spider, said spider and rim incorporating a-radial liquid passage leading into the hub, and
a pipe section abutting and protruding from the front face of the spider concentrically with the hub and of a diameter to intersect the said apertures intermediate the hub and the rim, thereby providing for free fiow of external air from front to rear of the spider intermediate the rim and the pipe section.
2. In an airfoam nozzle, the combination of a tubular hub, a concentric'rim encircling the huband spaced from and united therewith by a spider having apertures therein extending substantially from the hub to the rim, the said rim having forwardly and rearwardly projecting portions overhanging the spider, a hose coupling sup ported at the rear of the hub and spaced both from the rear faceof the spider and from the rearwardly projecting rim portion, thereby permitting free flow of external air tothe rear face of the spider, and a pipe section protruding from the front face of the spider concentrically with the hub, the rear end of the pipe section being of a diameter to intersect the said apertures intermediate the hub and the rim, thereby providing for free flow of external air from front to rear of the spider intermediate the rim and the pipe section.
3. In an airfoam nozzle, the combination of a tubular hub, a concentric rim encircling the hub and spaced from and united therewith by a spider having apertures therein extending substantially from the hub to the'rim, the said rim having forwardly and rearwardlylprojecting portions over hanging the spider, and a pipe section protruding from the front of the spider concentrically with the hub and of a diameter adjacent the spider to intersectthe said apertures intermedi;
ate the hub and the rim, thereby providing for free flow of external air from the front of the spider to the rearthereof, intermediate the rim-v In the latter case, as is well known,
one of its ends abutting the front face of the spider, the diameter of said section being intermediate the diameter of the hub and rim and means to introduce foam-making liquids into the nozzle through said hub, the apertures in said spider constituting air passageways to said nozzle from both sides of said rim.
5. An airfoam nozzle as claimed in claim 4 in which the front face of the spider defines a cylindrical recess and the pipe section is telescopically received in said recess with the end of the pipe section abutting the front face of the spider and wherein screws extend inwardly from said hub into looking engagement with a portion of said section that is telescoped within said recess.
CHARLES H. LINDSAY.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS