Incendiary grenade

An incendiary grenade's casing has a fuze with a portion extending into the casing. Thermite disposed in the casing encases the portion of the fuze that extends into the grenade casing. Insulating material is disposed in the casing adjacent to the thermite. Layers of a titanium-boron intermetallic and an oxidizer are disposed in the casing. One layer of the titanium-boron intermetallic is adjacent to the layer of insulating material. This one layer of the titanium-boron intermetallic and a layer of the oxidizer adjacent thereto have a common-axis hole formed therethrough that is aligned with the portion of the fuze. A separating material is disposed at each interface between the titanium-boron intermetallic and the oxidizer.

FIELD OF THE INVENTION

The invention relates generally to grenades, and more particularly to an incendiary grenade.

BACKGROUND OF THE INVENTION

Incendiary grenades are used to generate thermal energy that is useful in the destruction of biological agents and certain types of hardware. Typically, incendiary grenades contain a thermite (e.g., aluminum/iron oxide) that, when ignited, generates flame temperatures of 4000-5000° F. for a few seconds. However, this burn temperature and burn duration may not be sufficient for some applications.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide an incendiary grenade.

Another object of the present invention is to provide incendiary grenade having improved burn temperature and burn duration capabilities.

Still another object of the present invention is to provide incendiary grenade that is safe to handle and store.

In accordance with the present invention, an incendiary grenade includes a casing having a fuze with a portion thereof extending into the casing. A layer of thermite disposed in the casing encases the portion of the fuze that extends into the grenade casing. A layer of insulating material is disposed in the casing adjacent to the layer of thermite. Layers of a titanium-boron intermetallic and an oxidizer are disposed in the casing. One layer of the titanium-boron intermetallic is adjacent to the layer of insulating material. This one layer of the titanium-boron intermetallic and a separate layer of the oxidizer adjacent thereto have a common-axis hole formed therethrough. A separating material is disposed at each interface between the titanium-boron intermetallic and the oxidizer. A portion of the separating material extends perpendicular from each of the interfaces between the titanium-boron and the oxidizer along a length of the common-axis hole.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and more particularly toFIG. 1, a cross-sectional view of an incendiary grenade in accordance with an exemplary embodiment of the present invention is shown and is referenced generally by numeral10. The novel aspects of grenade10reside within the grenade's casing. Accordingly, it is to be understood that the particular casing and casing components such as the grenade's handle, pin, etc., are not limitations of the present invention. By way of an illustrative example, grenade10may be structurally based on the casing and casing components of the U.S. military's AN-M14 thermite grenade.

The casing and casing components of grenade10are referenced by the base numeral12. Briefly, the grenade's outer casing is referenced by numeral12A, the grenade's handle is referenced by numeral12B, the grenade's pin is referenced by numeral12C, and the grenade's fuze is referenced by numeral12D. Fuze12D (e.g., the U.S. military's M201A1 fuze) extends partially into casing12A. The function and operation of pin12C, handle12B, and fuze12D are well understood in the art and will not be explained further herein.

A starter material14encases the portion of fuze12D that extends into casing12A. For example, starter material14may include a layer thereof (as shown) filling the upper regions of casing12A. Starter material14is any acceptable material that initiates a burn reaction when fuze12D is activated/ignited. Generally, starter material14is a thermite such as aluminum/iron oxide.

Adjacent the starter material14is a layer of insulating material16. Insulating material16may be any material that resists burning when starter material14is ignited. In this way, the burn reaction of ignited starter material14eventually burns through the insulating material16. Suitable materials for insulating material16may include plastic, wool, and cardboard.

Filling the remainder of casing12A is at least one layer of a titanium-boron intermetallic and at least one layer of an oxidizer. In the exemplary embodiment illustrated inFIG. 1, three layers18A,18B and18C of a titanium-boron intermetallic are alternated with three layers of an oxidizer20A,20B and20C. Each intermetallic layer18A/18B/18C is a titanium-boron intermetallic composition containing titanium, boron, and binder materials such as carboxyl-terminated butadiene and polytetra-fluoroethylene. The particular formulation may be adapted for a particular application as would be understood in the art. Further, it is to be understood that more or less alternating layers, that is, the number of alternating layers, of intermetallic and oxidizer material may be used without departing from the scope of the present invention. To prevent any migration between intermetallic layers18A-C and oxidizer layers20A-C, a separating material layer22(e.g., a plastic material or an insulating material) is disposed at each inter-metallic/oxidizer interface, that is, the separating material layer22is situated intermediate each of the intermetallic layers and the oxidizers layers, respectively.

Regardless of the number of intermetallic/oxidizer “sets” used in grenade10(e.g., layers18A/20A form a first set, layers18B/20B form a second set, etc.), an inter-metallic layer is always disposed adjacent insulating material16. In this way, the initial reaction from ignited starter material14is first provided to the intermetallic (e.g., intermetallic layer18A in the illustrated embodiment). As intermetallic layer18A burns, the reaction byproduct, that is, titanium-diboride, is generated and provided to oxidizer layer20A. A suitable oxidizer for use in the present invention is lithium perchlorate. However, it is to be understood that other oxidizers (e.g., sodium chlorate) could be used without departing from the scope of the present invention.

To expedite and enhance the burn attributes of grenade10, a hole24, that is, a common axis hole, which is aligned with the fuze12D, may be provided in one or more of the intermetallic/oxidizer sets. More specifically, such a hole24is always provided in the first intermetallic/oxidizer set that is adjacent insulating material16, and may be provided through additional sets as a means to control burn rate as will be explained later with respect to the embodiment illustrated inFIG. 2. In theFIG. 1exemplary embodiment, the common-axis hole24is provided through layers18A and20A.

Referring now toFIG. 2, another embodiment of the present invention is illustrated. In this embodiment, common-axis hole24is used as a means to increase the burn rate of the intermetallic/oxidizer sets. More specifically, hole24extends through two intermetallic/oxidizer sets (i.e., layers18A/20A and18B/20B). It is to be understood that hole24could also be extended through all intermetallic/oxidizer sets. In operation, the starting material14burns through the insulating layer16and the flame enters the common-axis hole24helping ignite the intermetallic/oxidizer sets.

As mentioned above, separating material layers22, e.g., an insulating material, are situated at each interface between each intermetallic layer18A,18b,18C, and each oxidizer layer20A,20band20C. The separating material layers prevent migration between the intermetallic and oxidizer layers of the present invention. Layers22may be installed in casing12A during the manufacturing process. Further, a portion of the separating material22extends perpendicular from each of the interface locations between each intermetallic layer18A,18b18C, that is, the titanium-boron, and each oxidizer layer20A,20B,20C, that is, the oxidizer, along a length of the common-axis hole24. However, the present invention is not so limited. For example, each intermetallic layer and oxidizer layer may be pre-formed in a cup designed to be placed/fitted in casing12A. For example,FIG. 3presents an isolated view of the alternating layer structure used inFIG. 1where intermetallic layer18A and oxidizer layer20A are each pressed into a donut-shaped cup32(e.g., a plastic cup) having a central hole32A, while intermetallic layers18B/18C and oxidizer layers20B/20C are each pressed into a conventional cup34. The pre-filled cups may be stacked in a grenade casing (not shown) with intermetallic/oxidizer interfaces being separated by the cups.

The advantages of the present invention are numerous. The layered titanium-boron intermetallic oxidizer construction provides high burn temperatures of approximately 7000° F. The layered construction and hole bored therethrough may be used to adjust the burn rate for a desired effect.

Finally, any numerical parameters set forth in the specification and attached claims are approximations (for example, by using the term “about”) that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be at least construed in light of the number of significant digits and by applying ordinary rounding.