US2832424A - Foam-fog applicators - Google Patents

Description

April 29, 1958 G. F. HuRs'r FoAM-FoG APPLICAToRs 2 Sheets-Sheet 1 Filed April 16. 1954 INVENTOR G'onooN F HuRs-r rNilmU ATTORNEYS April 29, 1958 G. F. HuRs'r FoAu-Foc APPLICATORS 2 Sheets-Sheet 2 Filed April 16, 1954 www www

BURUBUA nUnUnUn I I n n n n n i n n n n l n u l a l n u r l n 9 i NNN `T ma TR Nu WH m F. N 0 n m G United States arent hice FAM-FGG AFPLICATRS Gordon F. Hurst, San dose, Application April 16, 1954, Serial No. 423,674

9 Claims. (Cl. 169-45) This invention relates to lire ghting equipment and more particularly to foam and fog applicators for producing and controlling the iiow of materials for extinguishing tires. Such applicators are commonly known as guns and will be so termed herein.

lt has been recognized for many years that a solid stream of water is not only an inadequate rire extinguishing agent, but, in the case of tires involving volatile fluids, such as oil and gasoline, the application of a so-lid stream of water may spread the fire and increase fire damage.

Two agents have been developed which are particularly effective in controlling such res and have been used extensively particularly in military operations by the Navy and Air Force. The rst of these agents is foam which is a stable cohesive blanket comprised of a mass of small bubbles which effectively cools and smothers lires which are dicult to control by other methods. Foam may be produced chemically or mechanically and it is with apparatus for the mechanical production and application of foam that the present invention is primarily concerned.

The second of these agents now used for combating fires which cannot be controlled by solid water streams is fog which consists of a finely dispersed spray of water with or without fire extinguishing additives. While fog, under some circumstances, does not have the fire extinguishing eifectiveness of foam it is nevertheless preferred in many situations because of the protection it affords the fire ghter by screening him from the heat of a burning substance.

In many instances it is desirable that both kinds of equipment be available so that a selection of the type of equipment which may be used with best effect can be made instantly. Accordingly, in order to prevent duplication of equipment so-called all-purpose guns have been developed by which either foam or fog may be delivered.

In the past such combined guns have been characterized yby relatively poor performance as compared with the single purpose guns designed specifically for either the delivery of fog or foam and are often cumbersome, expensive and fail to produce foam effectively or fail to provide adequate control of the quantity and pattern of the discharged agent. Also many of the existing guns of this type require separate spray heads, adapters or other auxiliary equipment which must be installed or removed to permit conversion between fog and foam.

It is accordingly the major purpose and object of the present invention to provide improved guns of the allpurpose type which are capable of readily selectively producing fog or foam.

It is a further object of the invention to provide improved combined fog and foam guns which may instantly and easily be converted from the production of foam to the delivery of fog and vice versa without the installation or removal of auxiliary units.

It is also an object of the invention to provide improved combined fog and foam guns having improved foam generating and shaping characteristics in which the foam is Patented Apr. 29, 1958 @i fully developed in a primary chamber and is shaped and discharged in a desired pattern in an enlarged secondary chamber.

lt is still another object of this invention to provide a combined foam fog gun with a rotatable valve body having parallel axially extending passages therethrough for selective seaied communication with a single inlet passage in a stationary head or handle section and a novel seal construction therefor.

lt is an additional object to provide combined foam and fog guns having separate controls for regulatingthe quantity and pattern of the discharged agents, each set of controis being operable independently of and without affecting the other controls.

it is a further object to provide improved foam and fog guns which are of simple, durable, lightweight and inexpensive construction.

Further objects and advantages will become apparent as the description proceeds in connection with the accompanying drawings in which:

Figure 1 is a partial longitudinal section of a preferred embodiment of the present invention;

Figure lA is a continuation of Figure l;

Figure 2 is an elevation of the discharge of Figures l and lA;

Figure 3 is a transverse section taken along line 3-3 of Figure l;

Figure 4 illustrates partly longitudinal section a modified invention;

Figure 5 is an enlarged fragmentary section of a portion of the gun of Figure 4; and

Figure 6 is a fragmentary sectional view showing a end of the gun in elevation and partly in embodiment of the present further modification of the invention.

Referring now more particularly to Figures 1 and lA of the drawings, the principal elements of the gun thereshown are the handle assembly indicated generally at 20, the selector valve body assembly 22, the aspirating cage assembly 2li, the primary foam generating chamber assembly 2o, the secondary foam shaping chamber and foam nozzle assembly 2d, the fog tube assembly 30 and the fog nozzle assembly 32.

The handle 2t) is of one piece construction and made of brass or similar material which is corrosion resistant and capable of withstanding the normal operating pressures. The grip portion 3o of the handle is hollow and at its lower end is provided with a threaded terminal portion 313 in which a sleeve extension 4t) is secured. The outer end of extension 4d is adapted to receive a standard sealed swivel hose connection assembly 42 connected to a high pressure flexible lhose d4 and including a. filter screen 46 which extends through the extension 40 into the lower end of the hollow grip 36. In operation the hose 44 is connected to a solution of water and a commercially available foam stabilizer which, as is well known in the art, is a substance for increasing the surface tension of the water, or to a source of water under pressure and is adapted through use of any suitable and well known pick-up tube structure to selectively aspirato a foam stabilizer into the water stream. Ordinarily the solution or water stream will be supplied at a pressure in the neighborhood of 8O to 600 p. s. i.

At its upper end, `the hollow grip 36 communicates through a passage Sil with an enlarged valve inlet passage 52 in which a sealing O-ring 54 and an annular valve seat member 56 are positioned, the latter preferably being constructed of reinforced nylon or like iiibrous material.

The valve seat member 56 is provided on its outer end witha thin sealing edge which is adapted to selectively sealingly contact the area of the end face of valve body 22 surrounding either aperture 60 are aperture 62 formed in the selector valve body 22 which is rotatably mounted on ball bearings 64 received in suitable grooves formed in the interior of a substantially cylindrical integral extension 66 of the handle 20 The bearings 64 also extend into grooves formed in the outer surface of the selector valve body 22 and thus function as thrust bearings preventing separation of the selector valve body 22 and the handle under all pressure conditions. The bearings 64 may be removed through openings provided in the grip which are normally closed by set screws 70. The connection between the grip 20 and the selector valve body 22 is completed by a sealing O-ring 7?. which prevents the escape of lluid to the bearings 64 or to the exterior of the selector valve body.

The passage 60 communicates with an enlarged cham ber 74 in valve body 22 in the outer wall 76 of which a plurality, preferably eight, spray nozzles 78 of conventional construction well known in the foam art are threadedly mounted. By appropriate change in the size of nozzles 78, the 4capacity of the gun may be varied from 20 to 50 gallons per minute.

The passage 62 is in turn connected through an internal centrally located passageway '79 to a boss 80 formed centrally of the selector valve body 22 into which is threaded a tube 82 which forms the initial portion of the fog tube assembly 30. The tube 82 extends through a central aperture in the wall 76 and is surrounded by sealing O-ring 84 mounted in the wall.

From the foregoing it will be apparent that with the selector valve body 22 positioned as shown in Figure l, iluid will be delivered from the hose 44 through the hollow grip 36, through the passage 60 to the chamber 74 for delivery through the'spray nozzles 78 to the aspirating cage assembly 24. However, if the selector valve body 22 is rotated 180 from the position shown in Figure l, the aperture 62 will be put into registry with the aperture 50, ilow through aperture 60 will be cut off and established through aperture 62 and passage 79 to the interior of the tube 82 for delivery to the fog tube assembly 30. To facilitate rotation of the selector valve 22 an operating handle 86 is mounted in a side wall thereof. To retain the selector valve body 22 in either of its adjusted positions a trigger type latch 90 is pivoted as at 92 on the grip assembly and is urged by a spring 94 into contact with bifurcated upper and lower abutments 96 and 98 on the selector valve body. It will be appreciated that other conventional detent structures may be used in place of the trigger 90.

The aspirating cage 24, which is preferably an aluminum alloy casting, is threaded onto the selector valve body 22 at 100 and is provided with a convergent wall portion 102 leading to a throat portion 104. The enlarged portion of the aspirating cage 24 has `a plurality, preferably four, circumferentially spaced air inlet openings 106 formed rearwardly of the outlet openings of the spray nozzles 78. It will be noted that the junction between the convergent wall portion 102 and the throat portion 104 of the aspirating cage is positioned slightly forwardly of the spray nozzles 78. `This arrangement, coupled with the location of the air inlets 106, permits the etiicient entrainment oflarge quantities of air in the spray discharge from nozzles 78 and precludes the possibility of the emission of foam through the passages 106 due to the residual orback pressure normally developed in forcing the foam through the gun. The mixture of water, foaming agent and air passes through the aspirating cage 24 into a primary foam generating tube 108 preferably formed of thin sheet aluminum which extends into the aspirating cage 24 and is secured thereto as by screws 110. The foam tube 108 thus forms with the fog tube assembly 30, an elongated primary foam generating chamber 111. Y

At its outlet end the tube 108 communicates with a secondary foam shaping chamber 112 formed between the fog tube assembly 30 and an enlarged foam discharge outer nozzle member 114 which is preferably an aluminum alloy casting. The nozzle member 114 which is provided with an annular inwardly extending flow control lip 115 is rotatably and slidably mounted on the tube 108 by a reduced portion 116 which carries a spaced pair of sealing O-rings 118.

A nozzle control ring 120 is secured to the tube 108 as by screws 122 and is provided with a threaded portion 123 which engages a matingly threaded portion 124 of the nozzle member 114 so that rotation of the latter will effect its axial displacement with respect to the former and tube Rearward movement of the nozzle member 114 is limited by cooperating abutment shoulders 126 and 128 formed on control ring 120 and nozzle member 114, respectively, and forward movement of the nozzle member 114 is limited by a stop member 130 secured to the outer end of the tube 108 by screws 132 for mating cooperation with the inner wall of transition section 134 connecting nozzle member 114 and reduced portion 116 of foam nozzle assembly 28.

The foam nozzle is completed by a torpedo 134 mounted on the outer end of the main fog tube 136 the other end of which is secured through an `adapter 138 to the tube 82.

To facilitate handling and to protect the gun, the central exposed portion of foam generating tube 108 and portion 116 of the nozzle member 114 are wrapped with lengths of braided cotton cording A140 and 142 and a protective neoprene bumper 144 is provided on the outer exposed end of the nozzle member 114. A synthetic rubber cover may be used, if desired, in place of the cording.

The quantity and pattern of the fog is controlled by the inner nozzle assembly 32 which comprises a female fog stream nozzle member threaded into the foam torpedo 134 and having a central fluid passage 152and a male control assembly or torpedo 154. An O-ring seal 151 seals member 150 and torpedo 134 against leakage therebetween. The torpedo assembly 154 comprises a .valve element 156 integrally secured to a positioning member comprising four vanesf158, the outer edges of which are adapted to be received with a sliding fit within the main fog tube 136. The torpedo assembly 154 is mounted on one end of a control rod 160 which extends along the length of the gun and is slidably received in aligned bores 162 and 164 in the selector valve body 22 and handle assembly 20 respectively. The bores 162 and 164 are sealed by O-n'ngs 166 and 168, respectively.

The outer end of control rod 160 is attached by nuts to a collar 172 secured by edge peening as at 174 to a knurled control knob threadedly mounted on a stud sleeve 176 which encircles control rod 160 and is threaded into the grip .assembly 20. Stud sleeve 176 is held in place by a set screw 178. Accordingly, rotation of control knob 175 will displace the valve member 156 axially with respect to the seat assembly 150 to permit desiredcontrol of the quantity and pattern of the discharged fog stream.

In operation, assuming the gun to be supplied with a suitable solution of water and foaming agent under pressure and the valve selector body 22 to be in the position shown in Figure l, the solution is delivered by the jets 78 in a number of nely dispersed streams to the aspirating cage 24. The ow of fluid through the spray jets 78 entrains large quantities of air which enter through the large apertures 106 in the aspirating cage and the turbulence in the aspirating cage causes the solution to mix with the entrained air to form foam. The formation of foam continues as the liquid-air mixture passes through the foam generating chamber 111 formed by tube 108 and final development of a cohesive fine bubble foam occurs in the tube 108 before the mixture reaches the secondary chamber 112 formed about the outlet of the tube 108. The secondary chamber 112 is thus utilized essentially only for shaping the foam and discharging it in the desired pattern. With nozzle member 114 in the position shown the foam will issue in a dispersed spray pattern. This pattern may readily be changed as desired by advancing nozzle member 114 to the right as viewed in Figure 1A, such movement of the nozzle being elfective to gradually eliminate the divergent effect of the cone and finally convert the spray pattern into a solid axially discharged foam stream. 1t is to be noted that since the foam generation and shaping are eiected independently the variation in the discharge pattern of the foam is effected without reducing the quantity of foam discharged so that regardless of the discharge pattern employed the foam will always be discharged at the predetermined maximum rate.

If conditions require, the gun can instantly be converted to deliver a water fog or stream by releasing the latch 90 and rotating the selector valve assembly 22 by the handle 86 to bring passage 62 into registry with passage 50. The introduction of foam stabilizer into the liquid supplied to the gun need not be discontinued since negligible quantities of foam will be produced. All of the uid will thus be delivered to the fog tube assembly 30 and will issue from the nozzle 150 when the valve 156 is opened by rotation of the control knob 175. An effective lire extinguishing agent is formed which screens the operator from the intense heat of the tire. Variation in both the discharge pattern and quantity of fluid discharged can be eifected by appropriate adjustment of the valve 156.

Basically the modified gun illustrated in Figures 4 and 5 is the same as the gun above described and is convertible for the production of either fog or foam and controllable in exactly the same manner as the gun of Figures 1 and 1A. However it will be seen from a comparison of Figures 1 and 1A and Figure 4, which are drawn to the same scale, that the primary foam generating chamber 190 and the secondary foam shaping charnber 192 of the gun of Figure 4 are considerably shorter than the corresponding chambers of the gun of Figures 1 and 1A. The shortening of the overall length of the gun is made possible by the use of the screen assembly indicated generally at 200 which accelerates the formation of foam and thus renders a chamber of the length of that shown in Figures l and 1A unnecessary. The aspirating cage 202 and the control ring 204, are generally similar to the corresponding elements 24 and 120 of the gun of Figures l and lA but are modified to receive the screen assembly 200. To this end, the aspirating cage 202 is provided with an enlarged bore 206 in which the screen assembly 200 is held by an annular extension 20S of the 4control ring 204. The aspirating cage 202 and the control ring 204 are provided with mating flanges 210 and 212 respectively which are secured together by screws 214. The screen assembly 200 preferably comprises three annular screen sections 216 separated at their peripheries by washers 218. The foam tube 220, which is secured to the control ring 204 by a plurality of screws 222, extends from the screen assembly 200 into the secondary foam generation chamber 192 where it terminates in a flared section 226 which functions as a stop for limiting forward movement of the outer nozzle member 22S. Except for changes in dimensions, the latter is generally similar to the nozzle member 114 described in detail above. The protective cotton cording 230 and the protective bumper 232 are similar to the corresponding elements described in connection with Figure 1A.

The two forms of the invention are generally interchangeable, the gun of Figures l and 1A being preferred in circumstances where it is necessary to project the foam stream as far as possible and the gun of Figures 4 and 5 being preferred under circumstances where size and weight are of controlling importance.

Both guns are characterized by simplicity, reliability, versatility and improved control characteristics and both may be converted from foam to fog or vice versa by relatively simple adjustments which may be made instantly and do not require the addition or deletion of auxiliary parts such as separate spray heads, nozzles or adapters generally necessary in prior constructions.

If desired, either of the basic guns may be equipped with the attachment shown in Figure 6 for producing a flat fog pattern. With further reference to Figure 6, the attachment as at 236 to the projection 238 formed on a ring 240 clamped between the fog nozzle and the foam torpedo 134.

In the position shown, the deector plate 234, which projects angularly across the fog stream discharged through the opening 152, will form the fog into a fiat pattern. When the usual fog pattern is desired the plate 234 may be swung back out of registry with the opening 152. By rotation of the ring 240 with the plate 234 in the position shown the direction of the flat fog stream may be varied as desired.

The invention may be embodied in other speciiic forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention. being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. A combined foam-fog gun or applicator comprising a hollow hand grip portion providing a liquid inlet and a liquid outlet terminating in an open ended chamber; valve means rotatably mounted in said chamber and having one end `wall providing a. pair of spaced ports adapted for selective communication with said outlet and respectively leading to an annular chamber in said valve means and a centrally located coaxial passage and also having an opposed end wall; passage means communicating with said centrally located coaxial passage and extending axially therefrom to form a fog discharge nozzle; a plurality of spaced spray jets extending through said opposed end wall into communication with said annular chamber; an annular passage surrounding said passage means and said spray jets and extending from said opposed end wall of said valve means to form a foam discharge nozzle and having a plurality of air admission ports adjacent said spray jets; means for supplying an aqueous liquid to said inlet; and means for rotating said valve means to selectively connect one or the other of said ports to said outlet to supply liquid to said spray jets whereby liquid sprayed therefrom will aspirato and entrain air into said sprayed liquid to produce foam in said annular passage and discharge it .from said foam nozzle or alternately supply liquid to said centrally located coaxial passage and said fog nozzle to thereby produce a fog spray.

2. The gun or applicator of claim l wherein said liquid outlet receives a fibrous cylindrical seat having an end protruding therefrom into sealing engagement with said one end Wall and of a diameter to encircle the selected one of said ports.

3. The gun or applicator of claim 1 wherein said foam nozzle surrounds said fog nozzle and is mounted for move ment with respect thereto to vary the pattern of said discharged foam between a widely divergent spray and a forwardly directed stream.

4. The gun or applicator of claim 3 wherein said annular passage is formed by a primary foam forming tube section carried by said valve means and having forwardly inclined air admission ports disposed rearwardly of said jets and an additional tube section mounted for movement axially of said primary foam forming tube section and having a secondary foam forming chamber of substantially greater cross-sectional area than said primary form forming tube section terminating in surrounding relation to said fog nozzle to form an annular foam discharge passage.

5. The gun or applicator of claim 4 wherein the exterior of said fog nozzle is of progressively increasing diameter from a point a substantial distance inwardly from said terminus of said additional tube section in its retracted position to a point just inwardly from said terminus in said retracted position and forms a flow dividing torpedo 4for imparting a divergent trajectory to foam discharged through said annular passage in the fully retracted position of said additional tube section and positions nearest said fully retracted position.

6. A foam and fog gun comprising means forming an elongated foam generating chamber having air inlet openings at one end, a plurality of spray nozzles adjacent said openings, means defining a restricted orifice at the end of said passage adjacent said foam discharge orifice, and means for selectively introducing fluid into said charn- `ber through said nozzles or into the end of said passage remote from said restricted orifice.

7. A foam and fog gun comprising, a first tubular member having a fluid inlet at one end and a fog discharge nozzle at the other end, a second tubular member surrounding said first tubular member in concentric relation therewith, the outer surface of said first tubular member in the inner surface of said second tubular member forming a foam generating chamber, a plurality of spray devices opening into one end of said foam generating chamber in surrounding relation with said first tubular member, means defining a plurality of air inlets in said second tubular member adjacent said nozzles, means forming cooperating surfaces on the adjacent ends of said tubular members to control the discharge of foam from said chamber, and means for selectively connecting said nozzles and said fluid inlet at said one end of said first tubular member to a source of fluid under pressure.

8. In a foam and fog gun, a first tubular member forming an elongated primary foam generating chamber, means forming a plurality of circumferentially spaced air inlets in the Wall of said chamber adjacent one end thereof, a plurality of spray devices adapted to introduce a dispersed mixture of water and foaming agent into said one end of said primary foam generating chamber, a second tubular member having a portion mounted on said first tubular member `for movement axially thereof, said second tubular member also having an enlarged portion forming an enlarged secondary foam generating chamber surrounding the Opposite end of said primary foam generating chamber, and fixed nozzle structure within the outer discharge end of said second tubular member having flow directing surfaces inclined with respect to the axes of said primary and secondary'foam generating chamber whereby upon axial movement of said second tubular member the configuration of said outlet maybe changed to vary the foam discharge pattern.

9. The gun of claim 8 togetherwith a screen assembly for accelerating the generation of foam, said assembly being mounted in and extending transversely of said primary foam generating chamber.

References Cited in the file of this patent UNITED STATES PATENTS

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