US3713589A - Fog nozzle - Google Patents

Abstract

The present invention comprises an improved fog nozzle consisting of a nozzle with a pair of generally concentric screens, wherein the screens have means for diffusing and dispersing a water jet to form a dense essentially uniform fog of predetermined pattern, the outer screen having an aperture therein of a diameter sufficient to let a solid water jet pass through and the means of entirely removing the inner screen from the path of the water being discharged by the nozzle. The fog nozzle is designed to generate water fog at low pressures and with the minimum amount of entrapped air. Means may be provided to reduce the discharge of water from the nozzle at any given pressure in order to maintain a desired pressure when necessary.

Description

limited States Patent 1 McNair et a1. Jan. 30, 1973 54 FOG NOZZLE 3,419,082 12/1968 O'Regan et al. ..239/5533 x [76] Inventors: Hugh McNair, Box Fruit 3,446,285 5/1969 Hout ..239/553.3 x

land Park, Fla. 32731; Stuart William Olson, 3111 68 S.W. 34th St., Gainsville, Fla. 32601 [58] Field of Search...239/370, 396, 428.5, 427, 504,

References Cited UNlTED STATES PATENTS Martin ..239/569 X Lewis et a1 ..239/553 X Thomsen ..239/396 X Watson et a1 ..239/427 Fitzgerald ..239/569 X lsenberg H239/590.3 X Eriksson ..239/428.5 X Freeman ..239/433 Primary ExaminerAllen N. Knowles Assistant Examiner--Gene A. Church Attorney-John C. La Prade [57] ABSTRACT The present invention comprises an improved fog nozzle consisting of a nozzle with a pair of generally concentric screens, wherein the screens have means for diffusing and dispersing a water jet to form a dense essentially uniform fog of predetermined pattern, the outer screen having an aperture therein of a diameter sufficient to let a solid water jet pass through and the means of entirely removing the inner screen from the path of the water being discharged by the nozzle. The fog nozzle is designed to generate water fog at low pressures and with the minimum amount of entrapped air. I

Means may be provided to reduce the discharge of water from the nozzle at any given pressure in order to maintain a desired pressure when necessary.

5 Claims, 2 Drawing Figures FOG NOZZLE PRIOR ART A search was conducted in the records of the U.S.

Patent Office and the following patents were located.

U.S. Pat. No. 2,829,874 Freeman U.S. Pat. No. 3,130,917 Aghnides U.S. Pat. No. 3,141 ,619 Benjamin et al. U.S. Pat. No. 3,363,841 Aghnides U.S. Pat. No. 3,388,868 Watson U.S. Pat. No. 3,419,082 ORegan et al. U.S. Pat. No. 3,446,285 Hout Applicants know of no closer prior art.

The present invention relates to an improved fog nozzle.

The invention, generally speaking, comprises a nozzle, equipped with a shut off valve, designed to produce an efficient solid stream or jet of water with suitable supporting structure for mounting a pair of generally concentric screens in the path of the water that flows from the nozzle, for the purpose of producing a discharge of water fog in a predetermined pattern. In the broadest sense, each of the concentric screens has a specific function and different structural features to accomplish such functions.

The present invention also has distinct advantages over the prior art in important respects among which are the following: (1) A fog of equal and consistent density is produced. (2) A controlled, predetermined pattern is produced. (3) A solid stream of water may be produced instantaneously to replace fog or fog may be produced instantaneously to replace water. (4) A constant flow rate may be produced.

it is one object of this invention to provide an improvied fog nozzle for producing a dense fire fighting fog.

It is one principal object of this invention to provide an improved fog nozzle that is capable of producing a controlled pattern of fog consisting of waterparticles that have been dispersed.

It is another important object of this invention to provide an improved fog nozzle that is capable of producing a fog of dispersed fine water droplets, where the fog is of essentially equaland consistent density throughout'the pattern.

It is another object of this invention to provide an im-. proved fog nozzle having structural features that will allow .the production of dense controlled fog and instantaneously allow the selection and use'of a solid jet or stream of water in place of the fog, both being of identical volume of discharge at all times. I

It is another object of this invention to provide a dense fog-of fine particle size with a minimum loss of velocity so as to'obtain' maximum projection or range at any given pressure.

It is another purpose of this invention to provide a fog nozzle wherein the volume of discharge can be reduced in order to maintain a desired nozzle pressure.

It is an additional object of this invention to provide a fog nozzle that will entrain the minimum amount of air during the formation of the fog so that if wetting agents and/r foaming agents are added to the water for fire fighting, air filled bubbles will not form until after impingement on the burning material, as the formation of foam bubbles at the nozzle greatly limits the projection or range of a fog discharge.

It is an additional object of this invention to provide an improved fog nozzle equipped with a pair of concentric screens that may be cone shaped. The screens may preferably be of different diameters to produce fog, wherein the inner screen can be completely removed from the stream of water instantaneously, the outer screen being protected from damage by the presence of a series of rods, or other protective mans so designed as not to appreciably impair the fog or solid stream discharge.

It is an additional object of this invention to provide an improved fog nozzle equipped with a pair of concentric screens wherein the outer screen contains an opening to allow passage there through of a solid jet of water without alteration or impediment for fire fighting or other useful purposes.

It is another object of this invention to provide a fog nozzle possessing the above desirable features that will at all times without adjustment provide the desirable combination of a high degree of personal protection, uniform coverage of the target area, and maximum forward projection under a wide range of pressures.

. While this fog nozzle is pecularly suited for use where water pressures and volume is limited to normal domestic water systems it is by no means confined thereto.

With these and other objects to be hereinafter set forth, we have devised the arrangement of parts to be described and more particularly pointed out in the claims appended hereto.

In the accompanying drawings, wherein an illustrative embodiment of the invention is disclosed FIG. 1 is a sectional view of one embodiment of the nozzleaccording to the invention.

F IG. 2 is a sectional view taken at 2-2 of FIG. 1.

Referring to the drawings, FIG. 1 illustrates the rearward portion of the body of a generally tubular nozzle 10, that may be gripped in the hand of the user. This portion of the tubular nozzle is usually cylindrical in shape, while the forward portion of the nozzle is flared out as at Hand may. also form a larger cylindrical section. The rearwardportion of the nozzle 10 may be equipped with athreaded opening 12 so as to be: at-

tached/to a-hose of appropriate size and equipped with a' conventionally threaded coupling, or other connection. A longitudinal opening or passage 13, which contains a conventional shut off valve, extends along through the center of the nozzle bodyto a reduced area opening or orifice 14' of the venturi type wherein water passing through orifice 14 increases in velocity-because of the smaller area of the opening 14 through which it passes. The base 15 of this portion of the nozzle may be equipped with standard screw threads as at 16, for easy attachment to the rearward portions of the nozzle, and

the tip of the reduced area at orifice 14 may be externally threaded to permit the attachment of an orifice of screen 22 may be equipped with suitable means to remove it from the path of the water jet when a solid stream is desired. Inner screen 22 may be fastened to a lever arm 24 by any conventional means such as welding, bracing, glueing, or by a threaded cap. The lever arm 24 which extends at substantially a right angle from the generally cylindrical outer surface 19, may be pivoted at point 26 -by a screw or other pivot member, and the arc of such pivot may be controlled by the length of the aperture through which said lever arm passes through sleeve 19. The perimeter of screen 22 may be encircled by a collar 23 that extends beyond screen 22.

Collar 23 has been found to provide an orderly mass of fog without entrapped air which can be easily directed as a visible column.

It is one function of generally cylindrical collar 23 to aid in the prevention of air entrapment at the point of discharge of water through screen 22. It is an additional function of the collar 23 to block the escape of water to the side and thereby to assist in the control of the pattern of discharge from screen 22 so as to direct same within the limits of screen 27. It should be understood that the water thus is directed, dispersed and broken up into a high velocity spray by screen 22 and the extended cylindrical collar 23 prevents runoff resulting from impingement-of water on sleeve 19 and helps to control the formation and direction of the spray in a forward, even though angular direction towards screen 27 without formation of droplets on the interior of sleeve 19. It is a function of sleeve 19, which may be essentially air tight, to further prevent the introduction of air into the high velocity spray discharge emanating from screen 22 and impingeing upon screen 27. Outer screen 27 that breaks up the high velocity discharge from screen 22 into fine fog particles and disperses same in a controlled pattern may be suitably attached to a collar 29 that may have screw threads 30 for a ready attachment with the forward end of sleeve 19. Outer screen 27 has an opening in the center thereof 28 to allow a solid stream of water to flow without alteration or impediment through opening 28 when inner screen 22 has been removed from the path of the water.

It should also be understood that in oneembodiment of the invention, screen 22 may be equipped with a small blocked off center section 31 that constitutes a solid portion .of the screen that does not permit the flow there through of any water. The function of this blocked off portion 31 is to aid in breaking up the water jet projected through opening 21 and to prevent the passage of high velocity spray through opening 28 in screen 27 by blocking the projection of high velocity spray that would if unblocked pass through opening 28.

In FIG. 2, the plan view of the generally cylindrical nozzle 10, is shown with inner'screen 22 having been pivoted to a position where it is in the path of the solid stream of water that is being discharged through orifice l4. Dashed lines show the position of inner screen 22 when not in the path of the solid stream of water being discharged from orifice 14. The collar 23 with screen 22 which is affixed to lever arm 24 may be swiveled by arm 24 being securely fastened by screw 25 to point 26. Other pivot means or equivalent means may be used to remove inner screen 22 from the path of the jet flowing through opening 21. For example, upper end of lever arm 24 may ride in a circumferential slot cut in wall 20.

A suitable mechanism such as a flat spring 32 bearing on inner screen assembly may be used to maintain inner screen 22 firmly in desired position.

The nozzle connecting core 33 may be connected by threads to the rearward portion of nozzle 10 as illustrated in FIG. 1. The spring mounting flange 34 is needed to secure spring 32 to the rear side of wall 20 by means of a pair of screws 35. The rear of wall 20 is denominated 38 for clarity. A ball valve control handle 37 is used to control ball valve 36.

As will be apparent to those skilled in the art from the study of FIGS. 1 and 2, and the embodiment of the invention disclosed therein, that the flow of water through the nozzle will remain constant whether the inner screen 22 is in the path of the water flowing through the nozzle, thereby producing fog or whether, on the other hand, the inner screen 22. has been removed from the path of the flow of water which will, of course give a solid jet stream of water with considerably greater range. It is also apparent that when a person is fighting a fire, there will be times when it will be desirable to have a solid stream of water with a much greater range of distance than is available when the fogging or fog technique is used. It is readily apparent from a study of FIG. 1 and 2 of the drawings that the user of the inventive fog nozzle may switch from the production of a dense fog to a solid stream or jet of water that has greater reach or distance by actuating lever arm 24 thereby pivoting inner screen 22 out of the path of the jet of water and allowing a solid jet of water to pass through opening 28 in outer screen 27 and visa versa may switch from a solid stream to fog without any loss of volume. Other equivalent means including the mechanism therefore will appear and be obvious to those having skill in this art for the purpose of moving or pivoting inner screen 22 out of the path of the jet of water as it passes through opening 21 in FIG. 1.

Screen 22 and Screen 27 may be made of any conventional screening material having, from approximately 800 openings to openings per square inch. One skilled in the art may select a suitable mesh for screen 22 and a suitable mesh for screen 27 and obviously, they may be the same or may be of different mesh if desired. Where maximum projection is desired the inner screen 22 will be of a larger mesh, i.e., having less openings per square inch, whereas if a fog of lower velocity is desired, a finer mesh may be used. The screen material may be aluminum, plastic, copper or any other suitable material.

The inventive fog nozzle, of this invention solves a substantial problem in fire fighting, firstly by providing a discharge of fine water fog of an essentially solid pattern with" an effective range that functions at normal domestic water pressures and, secondly by providing said fog at one instant and by flipping a lever or other equivalent operation providing a solid stream or jet of water with much greater range. The water employed can of course contain chemical additives, if desired.

It should be understood that the tubular section 10 with orifice 14 and sleeve 19 can be molded from plastic or other material in a one piece construction, with screen 22, collar 23 and lever arm 24 as well as screen 27 being mounted thereon by known methods.

The spring 32 used to put pressure on movable fluid diffusion screen may in combination with lever arm 24 be considered a setting means, used to set the movable screen 22 with circumferential collar 23. The arm 24 may be pivoted by the user so that the outer periphery of the screen or collar 23, if one is used in the particular embodiment may be pressured by spring means 32 and thereby set at any desired position. Other equivalent setting means coming within the scope of applicants invention will occur to those skilled in the art including variations in the lever arm arrangement and the spring means used to put pressure on the movable fluid diffusion screen assembly or collar.

The domestic water pressure at which the instant invention is operative may vary from approximately psi gage to over 100 psi gage.

If desired a series of guard rods (not shown) or other equivalent means may be mounted on collar 29 or elsewhere to afford protection to the fixed fluid diffusion screen 27.

Although the present invention has been described herein with reference to certain specific structural embodiments thereof, it will be understood that various modifications and equivalent structures may be resorted to without departing from the scope and spirit of the invention as set forth in the appended claims.

What is claimed is:

1. in fog producing and jet firefighting apparatus and the like, a readily held and manipulated nozzle housing said nozzle housing comprising a fluid inlet connecting means, a valve for controlling volume and pressure of fluid, a means provided for accelerating and forming said fluid into a cohesive jet, a movable fluid diffusion screen located in the path of and substantially co-axial to said cohesive jet, setting means provided for moving said movable fluid diffusion screen into and out of the path of said cohesive jet and setting the said screen in the desired position, a fixed fluid diffusion screen located sequentially downstream of and substantially co-axial to said movable fluid diffusion screen, wherein said setting means comprises the combination of a lever arm and a resilient spring means capable of moving and holding said movable fluid diffusion screen in the desired position.

2. The apparatus of claim 1, wherein the movable fluid diffusion screen is equipped with a solid center section that is not penetrable by a fluid.

3. The apparatus of claim 1, wherein the solid center section is surrounded with a screen through which dispersed fluid can be forced.

4. The apparatus of claim 1, wherein the movable fluid diffusion screen is equipped with a circumferential collar.

5. The apparatus of claim 4 wherein the circumferential collar extends beyond the tip of the movable fluid diffusion screen.

Claims (5)

1. In fog producing and jet firefighting apparatus and the like, a readily held and manipulated nozzle housing said nozzle housing comprising a fluid inlet connecting means, a valve for controlling volume and pressure of fluid, a means provided for accelerating and forming said fluid into a cohesive jet, a movable fluid diffusion screen located in the path of and substantially co-axial to said cohesive jet, setting means provided for moving said movable fluid diffusion screen into and out of the path of said cohesive jet and setting the said screen in the desired position, a fixed fluid diffusion screen located sequentially downstream of and substantially co-axial to said movable fluid diffusion screen, wherein said setting means comprises the combination of a lever arm and a resilient spring means capable of moving and holding said movable fluid diffusion screen in the desired position.

1. In fog producing and jet firefighting apparatus and the like, a readily held and manipulated nozzle housing said nozzle housing comprising a fluid inlet connecting means, a valve for controlling volume and pressure of fluid, a means provided for accelerating and forming said fluid into a cohesive jet, a movable fluid diffusion screen located in the path of and substantially co-axial to said cohesive jet, setting means provided for moving said movable fluid diffusion screen into and out of the path of said cohesive jet and setting the said screen in the desired position, a fixed fluid diffusion screen located sequentially downstream of and substantially co-axial to said movable fluid diffusion screen, wherein said setting means comprises the combination of a lever arm and a resilient spring means capable of moving and holding said movable fluid diffusion screen in the desired position.

2. The apparatus of claim 1, wherein the movable fluid diffusion screen is equipped with a solid center section that is not penetrable by a fluid.

3. The apparatus of claim 1, wherein the solid center section is surrounded with a screen through which dispersed fluid can be forced.

4. The apparatus of claim 1, wherein the movable fluid diffusion screen is equipped with a circumferential collar.

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