US3759216A

US3759216A - Smoke flare signalling and marking device

Info

Publication number: US3759216A
Application number: US00095111A
Authority: US
Inventors: V Sanders; A Scotchie
Original assignee: Northrop Carolina Inc
Current assignee: Northrop Grumman Systems Corp
Priority date: 1970-12-04
Filing date: 1970-12-04
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

A visual signal device which is floatable on water when energized to produce smoke which comprises a cartridge containing a smoke-generating composition, an inflatable floatation member disposed adjacent to the smoke composition cartridge, means for conducting a portion of the gas generated from the ignited smoke composition into the floatation member to expand such member and thus serve as a float for the cartridge, and separate means for conducting a major portion of the gas to the environment, bypassing the floatation member to serve as a smoke marker.

Description

limited States Patent Sanders, deceased et a1.

SMOKE FLARE SIGNALLING AND MARKING DEVICE lnventors: Victor M. Sanders, deceased, late of Asheville, N.C. by Nellie M. Sanders, executrix; Andrew A. Scotchie, Asheville, N.C.

Northrop Carolina, lnc., Swannanoa, N.C.

Filed: Dec. 4, 1970 Appl. No.: 95,111

Assignee:

U.S. Cl. 116/124 B, 9/9, 102/65 lint. Cl. G091 9/00 Field of Search 116/114, 124, 129,

References Cited UNITED STATES PATENTS 9/1943 Le Comte 116/124 B UX 4/1944 Oliver 116/26 X 7/1947 Van Karner 4/1961 Jackson [451 Sept, 19,1973

3,167,050 1/1965 Johnson 116/124 B 3,427,973 2/1969 Beers 3,520,275 7/1970 Gawlick et a1. 116/124 B FOREIGN PATENTS OR APPLlCATlONS 693,479 9/1964 Canada 116/124 B Primary ExaminerLouis J. Capozi Attorney-Sokolski dz Wohlgemuth and W. M. Graham [57] AWS'HRACT A visual signal device which is floatable on water when energized to produce smoke which comprises a cartridge containing a smoke-generating composition, an inflatable floatation member disposed adjacent to the smoke composition cartridge, means for conducting a portion of the gas generated from the ignited smoke composition into the floatation member to expand such member and thus serve as a float for the cartridge, and separate means for conducting a major portion of the gas to the environment, bypassing the floatation member to serve as a smoke marker.

7 Claims, 3 Drawing Figures Pmzmin w 3.759.216

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p x 2 f) i 1 35 1 INVENTORS 1 VICTOR M. SANDERS BY ANDREW A. SCOTCH/E SOKOL SKI a WOHLGEMUITH PATENTED 3.759.216

SHEEI E [If 2 /O5 1 [ii L]: //5 k //2 I18 l I I II FIG 3 INVENTORS VICTOR M. SANDERS BY ANDREW A. SCOTCH/E SOKOLSK/ 8 WOHLGEMUTH ATTORNEYS SMOKE FLARE SIGNALLING AND MARKING DEVICE Prior to the herein invention it has been recognized that it is desirable to have a smoke marker or flare that can float on the water. Many applications for the utilization of smoke markers involve identification of positions through the use of a smoke marker in environments containing water, such as marshes, rivers, lakes, and even the ocean. The smoke markers are often projected from a gun or can even be thrown, in the form of a grenade or the like. Obviously, if the marker becomes submerged in the water or is disoriented in the water, such that the burning surface is wetted, extin guishment of the smoke composition can readily occur. Thus, one of the important requirements in providing a smoke marker for utilization in water environments is that it be capable of floating in a proper position in the water even after projection, so that the smoke generated will be directed in an upwardly manner away from the water.

Most all of the prior art devices for floating smoke markers utilized a can or similar element containing the smoke, which had a large open enclosed area therein which served as a ballast to provide flotation. The main problem with these conventional flotation markers is that they do not provide sufficient stability in extremely rough seas, nor stability when the markers are projected from a gun or such into water. Further, and of importance as well, is the fact that the large ballast area increases the overall size of the marker significantly. More recently designedfloating markers have utilized casings of foamed material, such as foamed polystyrene or the like, to provide flotation. However, once again, this significantly increases the size of the marker and makes it considerably more bulky than desired. Further, these materials in some instances add weight, while in other instances they provide for a fragile outer surface. Even these devices, however, do not provide satisfactory flotation in many environments.

Thus, an object of this invention is to provide an improved floating smoke signal or marker having improved flotation properties.

Another object of this invention is to provide an improved floating smoke signal or marker that is compact and lightweight.

The above and other objects of this invention are accomplished by the herein floating smoke signal which comprises a casing containing a conventional smoke composition. A port is provided on one side of the casing to allow the smoke to escape when the composition is ignited by an igniter. There is additionally provided at least one secondary port in the casing containing the smoke composition. The secondary port communicates with the interior of a hollow inflatable floatation member which is affixed and sealed to the casing containing the smoke composition. When the smoke composition is thus ignited, a portion of the gas generated will flow through the secondary port and expand the floatation member which can be of cloth or various water impermeable materials. Before the smoke is ignited, the floatation member material is tightly compacted, taking up little weight and volume within the device. When expanded after the smoke composition has been ignited, the floatation member provides a relatively large surface area lending great stability for the marker when in a body of water. Thus, the diameter of the inflated member can be from 2 to 3 or more times greater than the diameter of the smoke producing device. In a first embodiment of the invention, the casing containing the smoke generating composition, together with the attached floatation member, is disposed within an outer shell or housing from which it is ejected after the smoke composition is ignited generating gaseous pressure. in this embodiment, the shell is projected from a gun or suitable device. in another embodiment of this invention, the casing for the smoke generating composition is esentially a grenade housing which contains the smoke composition and the floatation member. A port is provided for directing a portion of the smoke gas to inflating the floatation member in the manner previously described, while the main portion of the gas will be directed outwardly from the grenade.

It is believed that the invention will be further understood from the following detailed description and drawing, in which:

FIG. l is a cross-sectional view of a first embodiment of a floating smoke device capable of being propelled from a gun.

FIG. 2 is a pictorial representation of the. device of FIG. l where the floatation member is expanded and floating on water.

FIG. 3 is a partially sectioned view of a hand grenade smoke generating device of this invention.

Turning now to FIG. ll, there is seen a smoke marker 11 which is capable of floating on water. In this embodiment the device comprises an outer shell 13 having a cylindrical body closed at one upper end 15. Closed end 15 has a threaded aperture T7 in which is disposed a delay assembly l9 containing a propellant delay composition Zil. End 15 further has an O-ring seal 23 about its outer circumference which enables it to be engaged with a conventional cartridge case having a primer percussion disposed therein. Further indents 25 can be formed in end 15 to lessen the weight of the overall device.

The shell 13 should preferably be formed of a suitable polymeric or plastic-material to also decrease the weight. it is to be noted that below the O-ring seal 23 there is located an enlarged ridge portion 2'7 having a greater diameter than the main cylindrical body of the shell. This enables the device to engage the rifling bore of the gun utilized to project the marker which may comprise a conventional hand grenade launcher.

The open bottom end 29 of the shell 13 is enclosed with a generally hemispherically shaped ogive end cover 311 which is sealed thereto by an O-ring 33 such that the ogive 31 can be separated from the shell 113. The ogive portion 31 once again is formed of a suitable plastic polymeric material as the shell i3. As will be explained, the shell 13 and ogive end cover 3i merely serve to suitably enclose the smoke marker of the invention so that it can be suitably projected from a gun or other device, and are eventually separated after projection to allow the exposure of the marker.

Within the shell ll3 there is disposed the main marker device 35 which is comprised of a circular plate 37 having a cylindrical chimney portion 39 formed therewith and extending upwardly toward the top end of the outer shell. Plate 37 has a circumferential indentation 41 formed about its periphery. Crimped to this indentation 4t and thus affixed to the plate 35 is a casing d3 containing the smoke composition 45. Casing d3 has dimensions to conform to the inner diameter of the shell 13 and ogive cover 311. The plate 37 and casing 43 are preferably formed out of a lightweight metal, such as aluminum or the like.

The description of the device as follows will be explained with regard to the assembling thereof. As can be appreciated, the smoke composition 45 in its casing 43 can be affixed by the crimp to notch 41 at any stage in the assembling of the device and is independent from the assembling of the remaining portion. An inflatable floatation member 47 is comprised of two halves as seen in FIG. 2 particularly which are sewn about their outer periphery 49 after both such halves are separately affixed to the device.

To assemble the device, a spacer element 51 is disposed on top of the plate 37. Plate 37 is provided with a plurality of vent apertures 53 with one shown in the Figure. Typically, three equidistantly spaced vents can be used. Additionally, the plate 37 is provided with threaded holes 55 which can receive bolts 57. Preferably three such equidistantly spaced threaded holes 55 are also provided in plate 37. As can be seen, the spacer 51 has an inner diameter 61 which bisects the vent apertures 53. Thus, the notched portions 59 are required adjacent each vent 53 to provide sufficient area for the gas to be vented to the floatation member. To assemble the device, spacer 51 is aligned relative to plate 37 such that holes provided in the spacer are properly aligned with the threaded hole 55 and notched portions 59 are co-aligned with the vent holes 53. The lower one-half portion of the floatation member is then laid on top of the spacer 51. The floatation member has holes provided therein for alignment with those provided in the spacer 51, as well as notched areas about its inner diameter to co-align with the notched area 59 in the spacer.

Overlying the floatation member and sandwiching it to the spacer 51 is a plate 63 having an inner diameter 65 slightly greater than the outer diameter of the chimney portion 39. The plate 63 is secured to the main plate 37 by bolt 57 which passes through the floatation member material 47 and spacer element 51. Plate 63 is preferably formed of a plastic insulation material that will not melt at the temperatures generated by the smoke composition. Generally, plate 63 can be of the same material used for the spacer element 51 and can be, for example, an asbestos filled phenolic plastic.

Plate 63 serves two main functions. The first function is to secure the floatation member 47 by sandwiching it to the spacer 51. Secondly, the plate 63 serves to deflect hot solid particles generated from the ignition and smoke compositions when it is first ignited and thus preventing them from entering the floatation member 47. This feature can be appreciated since the plate 63, as can be seen, blocks the direct pathway from the vent hole 53 and notched areas 61 in spacer 51. However, the space between the inner diameter 65 of plate 63 and the chimney 39 should be equivalent in area to the total area of vent holes 53, so the gas passing through vent holes 53 is not effectively restricted as to the volume of flow, but rather is forced to take a path whereby individual solid particles of ignition composition would be deflected back toward the smoke composition 45 allowing only the gaseous products of the ignition and smoke compositions to pass into the floatation member 47.

The spacer plate 51 serves the function mainly to prevent heat transfer from the plate 37 to the to prevent the floatation from becoming burned or deteriorating during the generation of the smoke.

After the lower half of the floatation member is affixed to the device, the separate upper half is then ready for attachment. A proportion of chimney 39 has a slightly reduced diameter to provide a ledge 67 upon which rests an additional plate 69 of the same material used in spacer 51. The upper half of the floatation member is then placed between plate 69 and a washer 71 comprised of asbestos or the like. A metal spring clamp 73 is then seated over the washer 71 gripping the chimney 39 and clamping the washer 71 and floatation member to the plate 69 in tight fitting sealing engagement. Washer 71 of asbestos or other insulating material serves to prevent heat from being conducted from the metal clamp 73 to the floatation member, much in the same manner that the spacer 51 prevents heat conductivity to the lower half of the floatation member.

After both halves of the floatation member 47 are attached to the device they are then sewn together about their outer periphery 49 to provide a tight seal. The floatation can be comprised of virtually any coated fabric, such as linen, cotton, fiberglass cloth, dacron and the like. The fabric is coated with, for example, a silicon coating to eliminate porosity and protect the material from the hot smoke deposits. Obviously, other suitable coatings can be utilized for the same purposes. After the ballute is sewn, the entire device 35 is ready to be disposed in the shell 13.

Prior to insertion in the shell, a metal bearing plate 75 is inserted in the casing 13 adjacent the top inner portion and aligned with the threaded aperture 17 It is noted that the bearing plate 75 has a hole having an inner diameter 77 which is less than the diameter of the chimney 39. The small inner diameter 77 is disposed adjacent the chimney 39 and flares outwardly toward a larger diameter portion 79 corresponding to the threaded aperture 17. The purpose of this construction will be explained in the operation of the device.

To operate the smoke marker, the entire device 11 is affixed to a conventional cartridge element. It is then placed in a suitable gun or other means for projecting the device. When fired, the cartridge is initially detonated providing the gaseous force to push the entire device 1 1 as seen, out of the gun barrel, while also serving to ignite a first fire composition 21(a) which in turn ignites the delay composition 21 in the part 19. The delay composition-21 can be a conventional one such as set forth in specification MIlj-T-23 132, Series II. This is referred to as a tungsten delay composition. The composition 21 can, for example, provide a delay of five seconds between the projection of the marker from the gun to the ignition of the smoke. As the delay composition 21 burns, it forms a slag in the plug 31 and closes or significantly reduces the opening 79 therein, effectively blocking the escape of any gas from chimney 39.

The smoke composition 45 is preferably comprised of an initial layer of a first fire mix $1 immediately under the chimney 39 such that the hot gases generated by the output ignition composition 21(b), adjacent to the delay composition 21, initially strike the first fire mix 81 causing the ignition thereof. The first fire mix can be preferably a thin coating of any standard ignition material, such as boron potassium nitrate having thennite additives therein. First fire mix 81 serves both the function of igniting the main smoke composition and generating sufficient initial gas to eject the marker from the outer shell 13.

When the first fire composition is thus ignited, the gas generated thereby passes up through chimney 39 and bears against bearing plate 75. As indicated, the hole 79 in the plug 19 is closed by slag from the first fire composition. Thus, the gas generated by the first fire mix serves to propel the marker from the shell l3 forcing the ogive end cover 31 therefrom as it is projected. This can be accomplished before or after the device strikes the water. if fired into the water normal ejection of marker from the outer shell takes place, ignition of the smoke and inflation of the floatation member occurs, and the marker rises to the surface to emit a normal smoke signal.

The bearing plate 75 serves a function of taking the load from the chimney 39 when the device is projected from the shell. Since the shell is formed of a plastic material, the metal bearing plate 75 is particularly useful to receive the significant load generated during the projection step. Concurrent with the gas formed in chimney 39 by the first fire mix, the floatation member 47 is internally receiving a gas from this mix and is immediately inflated once it is free from the confines of the shell l3 prior to striking water or, as the case may be, below the surface of the water.

The first main layer 83 of the smoke composition is preferably comprised of a fast burning smoke mix. This is to insure that the floatation member 47 stays inflated before water impact since the first fire mix fill is expended preferably before impact. For example, in a sodium picrate smoke system, the top composition 83 could be comprised of 55 weight percent sodium picrate and 45 weight percent white dye if a white color, for example, is desired.

The device can additionally have a middle smoke composition as a slow burning mix having less sodium picrate and comprise, for example, 50 weight percent sodium picrate and 50 weight percent white dye. Finally, a remaining third composition 97 of the smoke mix can be comprised of a slowest burning increment and comprise for example, 37.5 weight percent sodium picrate, 611 weight percent white dye, and 1.5 weight percent sulphur which serves to retard the burning rate of the mixture.

The smoke compositions are preferably insulated from the casing 43 by a liner 84 made of paperphenolic or other suitable material. The utilization of three increments of different burning rates in the smoke composition is not mandatory to the successful operation of the device. It is preferred that an initial relatively quick burning smoke composition is provided to insure as indicated, that the floatation member be inflated upon water impact. The remaining portion of the smoke composition can, however, have a single burning rate less than that of the initial layer. However, even the initial layer is not necessarily required in that in many instances the smoke composition will have a burning rate sufficient to insure that the floatation member is fully inflated upon impact. As can be appreciated, the invention is thus not dependent upon the composition of the smoke material 45 and any known or even yet to be discovered smoke compositions can be utilized in the device to provide the desired end result both providing smoke and maintaining inflation of the floatation member 47. Further, the smoke composition can be substituted with a conventional colored or White flare composition to provide a flame marker for night marking and signaling.

As can be readily seen, when the device till is floating in water 95, as seen in PlG. 2, the main portion of the smoke is directed upwardly out of the water from the chimney 39. The inflated floatation member d7 provides a large surface of water contact which is light weight yet adding great stability to the device as it floats, with the shell portion 35 submerged in the water.

Turning now to H6. 3., there is seen a hand grenade version of the device of this invention. The device is quite similar to a conventional hand grenade smoke, except for modification to incorporate the inflatable floatation member concept of this invention. The grenade is comprised of an outer casing 93 containing the smoke composition 95. Casing 93 is crimped to plate 97. The plate 97 has integrally formed therewith a cylindrical upwardly extending neck portion 99, and has plurality of spaced holes 1193 therein to serve as ports or chimneys for the emission of smoke. Unly one such port T93 is seen in the drawing. However, three or four equidistantly spaced ones can be utilized.

A portion of the inner diameter of the cylindrical portion 99 is threaded to receive a fuse assembly T95. Additionally, the cylindrical portion 99 is provided with a flat plate W7 integrally formed therewith parallel to plate 97 forming a circumferential chamber therebetween in which a ballute i199 is disposed. Ballute 199 can be affixed by adhesive or other suitable means to the respective plates 97 and 197. Tape llll ll or other suitable means can be utilized to enclose the chamber in which the floatation member T99 is located, as long as the material can be readily removed manually or due to the expansion force of the floatation member when it is filled with gas. A plurality of ports illl3 are located in plate 97 communicating the smoke composition 93 with the floatation member area, allowing escaping gases to expand the floatation member in the manner previously described in the embodiment shown in FlGS. ii and 2.

in this embodiment, the fuse assembly 1195 is of conventional construction having a firing pin i112 and fuse arm lid. A primer i115 actuates a delay charge til? which in turn ignites a fuse output ignition composition 129. The pyrotechnic composition of the fuse is similar to the delay assembly 119 previously mentioned, that is, a first fire composition llllti is initially ignited by the output of the primer illlfi. The first fire composition ignites the delay composition M9 (typical MlL-- T-23l32, Series ll). The delay composition llll9 burns the desired length of time and then ignites the output ignition composition T29. After the fuse output charge is ignited, the hot gas therefrom in turn initiates combustion of a layer of first fire mix ll2ll covering the smoke composition 95. The gas generated from the first fire mix exits through ports Th3 removing the cover T23 therefrom, which can be pieces of tape or the like. Additionally, the gas from the first fire mix causes pressure to build up within the ballute forcing it outwardly against its enclosing material W9, eventually blowing it away from the grenade and allowing the floatation member to expand in the manner previously described. The enclosing material il ll9 can be a tearaway cover which can be removed manually prior to throwing the grenade.

We claim:

ll. A floatable smoke signalling device comprising:

casing means,

a smoke generating composition housed in said casing means,

an inflatable floatation member housed in said casing means in a position proximate to said smoke generating composition,

said floatation member being attached to said casing means,

an igniter housed in said casing for igniting said composition so as to generate gas,

a port in said casing means for conducting a portion of the gas from said composition into said floatation member to inflate said member and a vent in said casing means for venting the remaining portion of the gas from said composition into the ambient environment.

2. The device of claim 1 wherein said casing means comprises an enclosed cartridge having a top plate integral therewith.

3. The device of claim 2 wherein said vent for venting the gas into the ambient environment comprises at least one primary opening in said plate and a chimney affixed to said plate surrounding the opening and extending from said cartridge.

4. The device of claim 3 wherein said inflatable member surrounds said chimney, a portion of said member being secured adjacent to said plate.

5. The device of claim 4! wherein the port for conducting a portion of the gas to said inflatable member comprises at least one secondary opening formed in said plate, there being a corresponding opening in the portion of said member adjacent to said plate whereby the gas can pass from said cartridge into said member.

6. The device ofclaim 5 and further comprising a second plate disposed between said secondary openings in said first mentioned plate and the opening in said inflatable member to prevent solid particles from entering said member.

7. The device of claim 5 and further comprising a separable outer shell enclosing the cartridge and inflatable member.

Claims

1. A floatable smoke signalling device comprising: casing means, a smoke generating composition housed in said casing means, an inflatable floatation member housed in said casing means in a position proximate to said smoke generating composition, said floatation member being attached to said casing means, an igniter housed in said casing for igniting said composition so as to generate gas, a port in said casing means for conducting a portion of the gas from said composition into said floatation member to inflate said member and a vent in said casing means for venting the remaining portion of the gas from said composition into the ambient environment.

5. The device of claim 4 wherein the port for conducting a portion of the gas to said inflatable member comprises at least one secondary opening formed in said plate, there being a corresponding opening in the portion of said member adjacent to said plate whereby the gas can pass from said cartridge into said member.

6. The device of claim 5 and further comprising a second plate disposed between said secondary openings in said first mentioned plate and the opening in said inflatable member to prevent solid particles from entering said member.