US3780655A

US3780655A - Signaling device

Info

Publication number: US3780655A
Application number: US00802308A
Authority: US
Inventors: R Allen; E Bement
Original assignee: US Air Force
Current assignee: US Air Force
Priority date: 1969-02-24
Filing date: 1969-02-24
Publication date: 1973-12-25
Anticipated expiration: 1990-12-25

Abstract

This invention relates to a sealed multicompartment signaling device, each compartment containing at least one material which is mixed with the material of the other compartment upon puncturing of the seal by a member contained in one of the compartments, as the result of an external force on the device.

Description

lJnited States atent [191 Allen et al.

[451 Dec. 25, 1973 SIGNALING DEVIICE [75] Inventors: Robert A. Allen, Tonawanda;

Elmore L. Bement, Buffalo, both of NY.

'[73] Assignee: The United States of America as represented by the Secretary of the Air Force, Washington, DC.

221 Filed: Feb. 24, 1969 211 Appl. No.: 802,308

[56] References Cited UNITED STATES PATENTS Bachelder .1 102/57 2,328,276 8/1943 Hunt 102/8 2,487,818 ll/1949 MacFarland.. 102/8 2,592,434 4/1952 Krasnow l02/92.7

2,929,325 3/1960 Lewis 102/58 X 2,958,277 11/1960 Snelling 1 102/6 3,158,995 12/1964 Sprague et a1. 60/211 X 3,326,129 6/1967 Gould 102/49.3

3,399,468 9/1968 Gahle 102/8 3,464,869 9/1969 Wystrach et a1 149/44 Primary ExaminerSamuel W. Engle Attorney-Arthur .l. Plantamura and Jonathan Plaut [5 7] ABSTRACT This invention relates to a sealed multicompartment signaling device, each compartment containing at least one material which is mixed with the material of the other compartment upon puncturing of the seal by a member contained in one of the compartments, as the result of an external force on the device.

7 Claims, 5 Drawing Figures PAIENTED M82 5 I975 SHEET 1 0? 2 IIIII I I I I III I I III I III I III INVENTORS ROBERT A. ALLEN ATTORNEY PATENTED U125 3, 780 655 SNEU 2 0F 2 INVENTORS ROBERT A. ALLEN BY ELMORE L.BEMENT ATTORNEY SIGNALING DEVICE This invention relates to a pressure sensitive device comprised of sealed compartments containing reactants and a puncturing device within or affixed to one of said compartments for breaking the seal and causing intermixing of the reactants.

It has become necessary to have an easily assembled and effective device to demark the movement and, preferably, location of men or machines in warfare, as well as for other purposes such as security of the home. Especially in jungle or otherwise difficult terrain, where the movement of troops may be hidden by foliage or by night movement, such an indicative device is desirable. Such devices have been proposed in the past, but they have suffered from a number of deficiencies, including: early or lack of detonation because of faulty design, especially in the placement of the puncturing member;

lack of design features allowing for random deployment over a terrain from the air or by other method without need of special implanting of the device for proper operation; or comparative slowness of the reaction causing detonation.

It is an object of this invention to provide an easily assembled, reliable explosive device to meet the need previously mentioned. These and other objects and advantages of this invention will become more apparent upon reading the following detailed disclosure.

This invention generally relates to a pressure sensitive device comprising in one embodiment a bottom section, a top section, said sections maintained separate from each other and each section provided with a compartment containing one of at least two reacting materials, which as a result of the reaction, when intermixed, may preferably trigger the emission of an audible and/or visible report. A puncturing device contained within or affixed to one compartment causes the rupturing of the separation between the compartments upon the application of external pressure.

More specifically, the device of one embodiment (which will be described in more detail with relation to the drawings) consists of a top and bottom compartment heat sealed together with a separating layer between the compartments, which contain ingredients that interact when intermixed. The top compartment, for example, contains an oxidizer and preferably heat sensitive explosive device. The lower compartment contains sufficient reactant to liberate heat and detonate the explosive device if included in the assembly when said reactant is mixed with the ingredient in the top compartment. Contained within the lower compartment is a rupturing member for piercing the separating layer, upon the application of external pressure to the device, for mixing the reactants separately contained in the compartments. Preferably, a strip of film is attached under the lower compartment to ensure detonation, as will be discussed further hereinafter, and to serve as an air foil and thus aid in dispersion of the device over a terrain when dropped from a higher altitude.

The device will now be described in more detail with reference to the accompanying drawings:

FIG. 1 of the drawing is a spatial arrangement of the elements making up the device in one embodiment of this invention. In actual arrangement, the components shown in FIG. 1 interfit with each other in the relationship shown in FIG. 2.

FIGS. 3, 4 and 5 show modifications of the embodiment shown in FIG. 2.

The device shown in FIGS. 1 and 2 of the drawing is made up of a top section 1 with a cavity 2 molded therein. The top section 1 may be molded of polyethylene. The lower section 3, also preferably made of polyethylene, likewise has a cavity 4 molded therein, said cavity 4 containing in this embodiment a dimple or upward protuberance 5. A separating or barrier layer of film 6, again preferably of polyethylene, separates the upper and lower sections 1 and 3 and their facing

cavities

2 and 4. It is preferable that all parts of the device be made of the same material, such as polyethylene, to facilitate heat sealing.

In the cavity 2 is placed an ingredient for reaction, for example, an oxidizer such as potassium permanganate, ground to about mesh, or even mesh or less, in one embodiment, and, preferably, a primer cap, for example, such as used for shotgun shells to be exploded by the heat generated by the reaction. In the lower cavity 4 is placed a ring 8. In the embodiment shown, the ring 8 is in the form of a circular base 10 and pointed sections 9 extending from the base. The points 9 will rupture the film 6 upon the application of external pressure, as will be described hereinafter. In assembly, the base 10 of the ring 8 encircles the upward extent of the protuberance S and is held thereby. In the cavity 4, with the ring 8, is placed a second reactant to react exothermically with the previously named reactant. The second reactant to be used with the oxidizer named above may be, for example, a polyol, such as glycerine, ethylene glycol or the like. In one illustrative embodiment, such reactant is a combination of ethylene diamine and ethylene glycol, for example, in the ratio of about 5 percent diamine and 95 percent glycol. The advantageous potentiating effect of the diamine on the reaction of potassium permanganate and a polyol are described in the application filed contemporaneously herewith and afforded the Ser. No. 802,307, and the tiling date Jan. 24, 1969 Instead of the 95 percent glycol and 5 percent diamine combination just referred to, it is advantageous to use dimethyl sulfoxide in the cavity 4. Said material increases the speed of the reaction taking place so that in about 20 milliseconds from rupture of the seal a flame is propagated. Since, however, dimethyl sulfoxide has a freezing temperature of about C., a mix ture of dimethyl sulfoxide and glycol is an advantageous further substitute where rapid reactions are desired, and has the advantage of depressing the freezing point. A 70 percent dimethyl sulfoxide/30 percent ethylene glycol mixture has a freezing temperature of below 0 C. The period before flame propagation after interval time for glycol/diamine-permanganate mixture described is about 750 milliseconds under ambient conditions. The dimethyl sulfoxide/glycolpermanganate mixture just discussed has an induction period of only aboug 20 milliseconds before flame propagation. The glycerine-potassium permanganate reaction first discussed has an induction period before flame propagation of greater than about 4 seconds.

Preferably, a tab 11 of polyethylene film is located below and connected to the lower section 3 to serve as an air foil and to minimize premature detonation, as will be discussed later.

In assembly, the barrier film 6 is sealed over the lower section 3, thus closing the cavity 4 with its ring 8 and reactant therein. Then the combination of the film 6 and lower section 3 is sealed to the top section 1, closing the cavity 2 with its contents therein. The 11 is then added, if desired, by sealing one end of it 12 to the under part 13 of the lower cavity 3 so that it will be sealed to one end thereof and otherwise hang free therefrom. The sealing may be affected by heat sealing or a suitable adhesive may be employed, as desired. As indicated, polyethylene is desirable as the film constituent, but other types of flexible film may be employed as desired.

The assembled device described in the paragraphs above with relation to FIG. 1, is shown in FIG. 2.

In use, the device preferably lies upon the terrain on the tab 11. The downwardly facing cavity 2 is thus above the upwardly facing cavity 4, with the barrier film 6 therebetween. When someone or a vehicle, for example, applies pressure to the device (in the case of a person by stepping on the device), the, outside is deformed and the points on the ring 9 are pushed through the barrier film 6. When this breaking of the seal between the cavities of the sections 1 and 3 occurs, the ingredients are forced to intermix and react. The reaction of the potassium permanganate with the ethylene glycol, in the illustrative embodiment, for example, liberates sufficient heat, the temperature during the reaction reaching above about 1,500 F., to create a visible indication and to detonate the primer cap 7, if included in the assembly. As discussed in the earlier referred to copending application, the use of ethylene diamine with the ethylene glycol in cavity 4 accelerates the reaction with the potassium permanganate from slower than about 4 seconds to less than about 2 seconds. Metal powders may be advantageously added to the oxidizer resulting in the increase of the temperature of reaction and creation of molten fluxes for better heat transfer. The addition of up to 10 percent aluminum powders, for example, and preferably about 7 percent, results in an increase in the temperature of reaction to thermite temperature range. Other metal powders, such as copper, zinc, iron and magnesium, may be added with magnesium and aluminum producing a flaring effect which is very effective in producing a visible signal.

The device may be dispersed about an area by, for example, dropping it from an airplane. The tab 11 acts as an air foil when said device is dropped, resulting in an even and gentle flight, without damage to the components, and dispersion of such devices throughout an area. Furthermore, the tab 11 provides the additional feature when added to the device and resting on the ground to act as a base with the two sections 1 and 3 thereabove. Pressure on the device from above against that base will not result in imbedding said device in the ground without detonation, but in more reliable detonation as a result of providing more insurance of rupture of the film 6 by the points 9. The definition in this specification of top and bottom compartments is based on the position of the tab. Obviously, it is not critical which ingredient for reaction goes in which compartment, nor which compartment contains the rupturing member. in one embodiment, the primer cap may also serve as the rupturing member by simply including a rupture causing surface on that primer cap to break the seal between the compartments.

It is important to note that inclusion of the rupturing device within or attached to one of the compartments,

but not as a part forming a compartment, results in a high reliability factor, because the rupturing device cannot be damaged in dispersion and serves no function in containing either of the reacting ingredients, and the material forming the compartments may be selected without regard to the specifications required for the rupturing member.

The potassium permanganate or other oxidizer used may alternately be in the form of pellet 14, say for illustration by 5/16 inch, which fills the cavity 2, as shown in FIG. 3. Pelletizing the powder allows for more of such powder being locatable in the cavity since the pellet is formed under pressure conditions, as is well known. The pellet may include a recess 15 to seat the primer 7. Holding the primer 7 in the fu'rther most position away from the other reactant may tend to elongate the period after rupture of the seal to deterioration of the primer. This would be particularly advantageous where the device is used for security and no injury to the intruder is desired.

The ring 8, in another embodiment shown in FIG. 4, is replaced by tack structure 16 located in the cavity. The head 17 of the tack may be located inside or outside (as shown in FIG. 4) of the cavity 4, with the point 18 extending upwardly. Compression of the device results in puncturing of the seal with the point 18. The tack head acts as a piston on compression of the device to drive the fluid in the cavity through the puncture. This pumping action results in contact of reactants and rapid explosion.

Provision may be made to produce even greater visual indication by the addition of the modification shown in FIG. 5. A lining 19 preferably, but not essentially, of polyethylene film, is attached as by heat sealing to the section 1, so as to surround the cavity 2. lnside that lining in the sack formed by the lining and the section 1 is then placed a die material which is dispersed upon the reaction taking place to cause a visual signal. If desired, the dye may contain such elements so as to emit radiation effects detectable by metering devices.

It is intended that this invention only be limited by the scope of the claims which follow. Details of the device design, the chemical and physical ingredients incorporated therein, and of assembly, may be altered without departing from the scope of the invention.

We claim:

1. A deformable signaling device comprising two facing cavities sealed from one another, materials in each cavity which when conbined will react, the material in one cavity including a reactant polyol and the material in the other cavity including an oxidizer and a primer cap for producing an audible report upon reaction of the polyol and the oxidizer, means joining the cavities together and means for breaking the seal independent of forming either of the cavities entirely contained within the cavity containing the polyol reactant, whereby upon application of external pressure the seal is broken allowing the polyol and the oxidizer to react.

2. A device according to claim I wherein the oxidizer is in the form of a pellet.

3. A device according to claim 2 wherein the pellet is grooved to receive the primer cap.

4. A deformable signaling device comprising two cup-shaped members each having a rim, and a barrier film situated between the cup-shaped members and heat sealed to their rims, the bottom cup-shaped memis affixed to the device.

6. A device according to claim 4 wherein the cupshaped members and the barrier film are of polyethylene.

7. A device according to claim 6 wherein a strip of polyethylene film is externally heated sealed to the device.

Claims

2. A device according to claim 1 wherein the oxidizer is in the form of a pellet.

4. A deformable signaling device comprising two cup-shaped members each having a rim, and a barrier film situated between the cup-shaped members and heat sealed to their rims, the bottom cup-shaped member having an inwardly protruding dimple at the bottom and containing a reactant polyol and a means for rupturing the barrier film located over the dimple, whereby upon application of external pressure the cup-shaped members are deformed so as to allow the barrier film to be ruptured and the oxidizer and the polyol to react, resulting in emmision of visual and audible signals.

5. A device according to claim 4 wherein an air foil is affixed to the device.

6. A device according to claim 4 wherein the cup-shaped members and the barrier film are of polyethylene.