US20130186295A1

US20130186295A1 - Diversionary grenade having watertight seal

Info

Publication number: US20130186295A1
Application number: US13/357,973
Authority: US
Inventors: Jacob Kravel
Original assignee: Combined Systems Inc
Current assignee: Combined Systems Inc
Priority date: 2012-01-25
Filing date: 2012-01-25
Publication date: 2013-07-25

Abstract

A grenade is defined by a body made from a rubberized material, the body including a hollow interior and a stem section. A cap is releasably secured to the stem section, the cap retaining a fuze assembly which is threadingly engaged therewith. The grenade is equipped with an ejection charge that causes said cap and said fuze assembly to be separated from said body prior to detonation of the grenade. A hydrophobic sealing layer applied to the exterior of the stem section and cap provides a watertight seal relative to the interior of the grenade, but without substantially interfering with the ejection of said cap and fuze assembly.

Description

TECHNICAL FIELD

The application relates generally to the field of non-lethal weapons and/or diversionary devices and more specifically to a non-lethal grenade having a seal that enables use in water environments.

BACKGROUND AND RELATED ART

There are numerous versions of grenades that are presently available for purposes of law enforcement, military and other related applications. Included among these devices are what are referred to as so called “non lethal” or distraction devices. These devices include, among others, “flash-bang” grenades and “stun” grenades, each of which are commonly designed to temporarily incapacitate a person or persons that are within a prescribed area or to cause persons to leave a prescribed area due to the detonation of a grenade therein. In the case of “flash hang” grenades, a combination of a released charges of intense flash illumination and auditory (loud sound) discharge are emitted by the grenade while in the case of “stun” grenades, a plurality of hardened rubberized pellets are caused to be released at high speed when the grenade is detonated. Other non-lethal versions can include those containing at least one of or combinations of chemical (e.g., tear gas) and other deterrent filler materials that are intended to cause considerable discomfort.
In the common course of use, each of the above-noted grenades is provided with a fuze assembly, which permits detonation of the device after a timed delay (i.e., a few seconds) following the release of an arming pin and safety lever by a user or launching apparatus. Commonly the time assembly is securably attached to a cap, the latter of which is secured by means of an interference fit with the remainder of the grenade body while the fuze assembly is threadingly engaged with the cap. An ejection charge is used prior to detonation of the grenade and following release of the safety lever to safely eject the fuze assembly and cap in order to permit the filler material within the grenade to be dispersed upon detonation. Failure to release the cap properly will yield unsatisfactory results and potentially dangerous safety issues due to the confinement of forces within the grenade body. Therefore, it is essential that the cap be properly jettisoned from the remainder of the grenade.
The use of these devices is increasing and as such are the number of possible applications, including those in environments for example in which grenades could be inventoried on boats, ships and naval vessels. It is therefore a somewhat competing interest to provide a grenade having increased versatility in terms of the environment in which it is used, but without sacrificing either functionality or manufacturability.

SUMMARY

Therefore and according to a first aspect there is provided a grenade, said grenade comprising a body made from a rubberized material, said body including a hollow interior and a stem section;
a cap attached releasably to the stern section of said grenade body;
a fuze assembly threadingly attached to said cap;
an ejection charge that causes said cap and said fuze assembly to be separated from said body prior to detonation of said grenade; and
a hydrophobic sealing layer applied to the exterior of said stem section and said cap, said sealing layer providing a watertight seal relative to the interior of said grenade without substantially interfering with the ejection of said cap and fuze assembly.
According to one version, the hydrophobic sealing layer comprises a liquified synthetic rubber. Preferably, this material can be applied at room temperature, such as by brush. Desirably, a minimum layer thickness in the range of about 0.001 to about 0.100 inches is preferred.
The grenade is preferably non-lethal wherein the cap is made from plastic or other suitable material that permits securement to the rubberized stern section while also pe miffing bonding relative to the applied sealing layer. The surfaces to be bonded can be abraded or roughened sufficiently prior to applying the sealing layer to better guarantee adhesion.
According to another aspect, there is provided a method for fabricating a grenade, said method comprising the steps of providing a grenade body made from a rubberized material, the grenade having a hollow interior and a stern section extending therefrom, attaching a cap to said stem section, said cap including a center opening sized for receiving a fuze assembly, said cap being releasably attached to said stem section, applying a sealing layer to the exterior of said cap and said stem section, including an attachment boundary therebetween wherein said sealing layer comprises a hydrophobic material, and attaching said fuze assembly to said cap.
The fuze assembly of the grenade includes an ejection charge for jettisoning said cap from said grenade body prior to detonation of said grenade, said sealing layer being applied so as not to substantially affect the ability of said ejection charge to jettison said cap and fuze assembly from said grenade. According to one described version, the fuze assembly is threadingly attached to the cap.
The cap can be made, for example, from a durable plastic material that enables release from the rubberized stem section while also permitting bonding thereupon by the sealing layer. The grenade according to a preferred version, as described herein, is non-lethal.
The sealing layer can be suitably applied. According to one described version, the layer is applied by brush. This sealing layer can be, for example, a liquified synthetic rubber. Preferably, the sealing layer can be applied at room temperature. The surfaces to be bonded can be abraded or roughened sufficiently prior to applying the sealing layer to better guarantee adhesion.
Additionally and according to one version, the method can further include the step of applying an epoxy to the threaded connection between the fuze assembly and the cap to further isolate and seal moisture from the interior of the grenade.
One realized advantage is increased versatility in the use of non-lethal devices in terms of naval, law enforcement and other applications in water environments.
Another advantage provided is that the waterproofing seal provided by the herein sealing layer does not interfere with the functionality of the grenade or its overall reliability.
Yet another advantage is that this waterproofing feature can be realized without having to substantially modify the design of the overall device and in which the sealing agent can be readily applied so as not to increase complexity in manufacturability or cost.
These and other features and advantages will be readily apparent from the following Detailed Description, which should be read in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, shown in section, of a prior art grenade.

FIG. 2 is a side elevational view, shown partially in section, of a prior art fuze assembly;

FIG. 3 is a side elevational view of prior art grenade, shown during release of the safety lever and prior to detonation;

FIG. 4 illustrates a partial partially exploded view of a prior art grenade, the grenade being similar to those depicted in FIGS. 1 and 3;

FIG. 5 is a side perspective view of a portion of the prior art grenade of FIG. 4;

FIG. 6 is a partially disassembled view of the prior art grenade, illustrating the ejected portion of the cap of the grenade of FIGS. 4 and 5 in a condition similar to that occurring just prior to detonation;

FIG. 7 is a partial side perspective view of a grenade in accordance with an exemplary embodiment of the present invention;

FIG. 8 is a side perspective view of the cap and grenade body of the grenade of FIG. 7; and

FIG. 9 is an enlarged view of the sealed area of the grenade of FIGS. 7 and 8.

DETAILED DESCRIPTION

The following embodiments described herein relate to a grenade having a sealing feature enabling the grenade to be effectively water-tight and therefore more versatile than previous known versions. Throughout the course of discussion, various terms are used to aid in providing a suitable frame of reference with regard to the accompanying drawings. To that end, terms such as “above”, “below”, “top”. “bottom”, “upward”, downward”, “proximal”, “distal” and the like are used throughout. These terms, however, are not intended to be overlimiting of the present invention as claimed. In passing, it should further be noted that the drawings in this application should not be necessarily relied upon in ten 135 of their depicted scale.
Moreover, the embodiments described herein relate specifically to a specific version of a so-called “non-lethal” weapon/device or grenade. It will be readily apparent that the concepts that are described herein, however, are also applicable to other fauns of weaponry used in conjunction with at least one fuze or fuze assembly to effect detonation thereof.
Referring to FIG. 1 a grenade 20 made in accordance with the prior art is shown, the grenade being defined by a body or housing 24 having a suitable shape and including at least one interior chamber 28. In the present example, the housing 24 is defined by a substantially spherical configuration with the exception of a substantially cylindrical neck or stern portion 32 having an open end. The entirety of the housing 24 and the stem section 32 is hollow, thereby permitting the inclusion of various components through the open end of the stem section. According to this version, the housing 24 and the stem section 32 are each fabricated by known means from a hardened rubber material each with fairly thickened walls to provide suitable structure but also maintaining a requisite level of elasticity.
As previously noted, the grenade 20 described herein is a so-called non-lethal grenade. A plurality of hardened (e.g., Durometer 70) rubberized pellets 36 are added according to this specific version as filler material within the hollow interior of the grenade housing 24, although other materials could be utilized. These rubberized pellets 36 are dispersed at a high speed over a predetermined radius upon detonation of the grenade 20 and are intended to stun or incapacitate persons within that radius. A cap 40 is engaged with the stern portion 32, the cap being made, according to this embodiment, from a moldable rubber and/or plastic material and having a downwardly extending portion 44 that is sized to create an interference fit with the interior walls of the cylindrical stem section 32 and an upper ledge 48 shaped to configure substantially to that of the stem section when the cap is fitted thereto. In addition, the mating surfaces of the cap 40 and stem portion 32 should be initially roughened in order to improve the fit therebetween. When mated the cap 40 is tightly, though releasably, attached to the grenade housing 24.
The cap 40 includes a center through opening or bore 52, the opening according to this embodiment including a set of screw threads (not shown) for receiving a portion of a fuze assembly 60, which is attached thereto. A portion of a known fuze assembly that is useful for the presently depicted grenade is shown in FIG. 3 for purposes of background.
The fuze assembly 60 is mounted to the cap 40. According to this version, the fuze assembly 60 includes an fuze body 64 that is disposed above the cap 40 and a lower extending portion 66 that extends downwardly into the central bore 52 of the cap 40. The fuze body 64 is made from a hardened metal such as steel or brass or constructed from other suitable material, the body retaining therein a striker 70 that is attached to one end of a striker spring 74 as well as a primer that is disposed within the lower extending portion 66, wherein the lower extending portion is a hollow member that retains at least one charge and is connected to at least one additional charge, in this instance, a flash charge 29, FIG. 1, disposed in the interior chamber 28 of the grenade body 24. A set of screw threads 67 are provided in an upper axial section, and at least one charge (not shown) so as to effect detonation of the grenade 20. The type of fuze used in the herein described embodiments is an M 201, pyrotechnic delay fuze. It should be noted in passing, however, that the specifics of the particular fuze assembly are not necessarily critical to the workings of the present invention, as described herein.
A safety lever 80 is attached to the fuze body 64 in biased fashion by means of the striker spring 74 wherein the lever is initially retained in place by means of an aiming pin 90 that is also attached to the fuze body 64 through a set of axially aligned lateral openings 37 that are formed in the fuze body 64 and safety lever 80. The safety lever 80 extends downwardly from the fuze body 64 and is pivotally or hingeably attached thereto in a releasable manner, the lever substantially conforming to the fuze body 64 and the grenade body 24, respectively.
Due to the chance of catastrophic injury that could occur if the arming pin 90 is prematurely or unintentionally is pulled, a retaining clip 98 is further provided. As shown in FIG. 2, the retaining clip 98 is provided as a separate component and is disposed between the threaded portion of the fuse body 64 and the cap 40 of the grenade 20. The retaining clip 98 is configured to retain a proximal ring portion 94 of the arming pin 90, thereby requiring both a transverse (twisting) motion followed by an axial (pulling) motion in order to effectuate the release of the arming pin and thereby effect release of the safety lever 80.
In operation and as noted. release of the aiming pin 90 from the retaining clip 98 is realized by a twisting motion of the proximal ring portion 94 of the pin. The retaining clip 98 according to this version is made from aluminum or similar material which is defined as a single separate component including an opening 99 that is sized to permit the clip to mounted onto the downwardly extending portion 66 of the fuze body 64, the retaining clip being mounted between the top of the cap 40 and the bottom of the fuze assembly housing. The clip 98 includes a pair of flanges that match corresponding opposing side walls of the fuze body 64 in order to align a clip portion 103 relative to the lateral openings 37 that support the firing pin 90 and subsequently the safety lever 80. The clip portion 103 according to this version is a substantially C-shaped spring configuration having a spacing that is sized to retain the proximal ring portion 94 of the firing pin 90 and in which elastic deformation of the spring clip portion is required in order to secure and release the pin.
Once the firing pin 90 has been released from the retaining clip 98, the pin can be axially pulled away from the fuze body 64, through the lateral openings 37 formed in the fuze body 64 and safety lever 80, thereby releasing the safety lever from its locked condition. Typically and upon pulling the arming pin 90, the user immediately pushes the safety lever 80 toward the grenade body 24 and hurls the grenade 20 toward a target. Alternatively, the grenade 20 is enabled by apparatus (not shown) prior to launching of same in a manner that is known. As shown most clearly in FIG. 3, release of the safety lever 80 causes the lever to pivot under the action of the preloaded striker spring 74 and further causes the striker 70 to also pivot and axially engage the primer 78 causing an ignition spark and thereby engaging the fuze assembly 60. In the above-depicted apparatus, an ejection charge is ignited, separating the cap 40 from the grenade body 24 followed by a delay charge after which the hardened rubberized pellets 36 (not shown in this view, refer to FIG. 1) and a high intensity illumination (flash) and/or sonic charge 29, FIG. 1, are dispersed in a radial (circular) pattern.
Referring to FIGS. 4-6, a similar grenade 20 is herein depicted in terms of its as assembled components. Similar parts are herein labeled with the same reference numerals for the sake of clarity. It should be pointed out that the explosive portions of the fuze assembly and the filler material of the grenade are not depicted herein for the sake of clarity. In terms of construction, the cap 40 is assembled to the top of the stem section 32 wherein the lower section of the cap is directly fitted within the stem section, the rubberized stem section expanding and permitting an interference fit with the upper ledge of the cap covering the stem section and in contact peripherally therewith.
The fuze assembly 60 is then assembled to the cap 40 by means of inserting the lower portion 66 of the fuze body 64 into the center bore 52 of the cap and threadingly engaging the components, drawing the fuze body 64 down onto the top of the cap. In the instance a retaining clip 98, FIG. 1, is utilized, the clip is first attached in overlaying fashion onto the lower portion 66 of the fuze assembly 60 with the clip portion 103 being aligned in relation to the lateral openings 37 in order to permit assembly of the firing pin 90.
A grenade made in accordance with one version of the invention is shown in FIGS. 7-9. For purposes of clarity, the grenade 120 shown is similar to that previously described. To that end, similar parts are herein labeled with the same reference numerals. Like the preceding, the grenade 120 includes a rubberized body 24 including a substantially cylindrically shaped stem section 32 having an open end, each of which are essentially hollow components. A cap 40 is used to cover the open end of the stem section 32, the cap including a downwardly extending portion 44, FIG. 1, and an upper ledge 48, FIG. 1, respectively, and in which the cap is fabricated, such as by molding from a plastic material such as polycarbonate, polyimide or other suitable material. As in the preceding, the cap 40 further includes a center bore or opening 52, FIG. 1, at least a portion of which includes a set of screw threads adjacent the upper ledge 48 and extending an intermediate axial distance.
A fuze assembly 60, in this embodiment an M201 pyrotechnic fuze, is used to detonate the grenade 120 is mounted to the cap 40, the fuze assembly including a fuze body 64 (partially shown) having a lower portion 66, FIG. 1, that is sized to be fitted into the center bore 52, FIG. 1 of the cap 40. A safety lever 80 is hingeably attached to the top of the fuze body 64 and is biased into a first position by means of a striker spring (not shown but similar to that shown in FIGS. 2 and 3) one end of which is attached to a striker (not shown in this view, but also similar to that shown in FIGS. 2 and 3), the safety lever being retained in the biased position by means of a firing pin 90 that is inserted through a set of lateral openings 37 formed in the fuze body and safety lever, respectively. A retaining clip 98 may also be used to retain the firing pin 90 to insure against premature release of the safety lever 80.
According to this version, a waterproofing sealing layer 136 is applied to the exterior of the cap 40 and the stem section 32 of the grenade body 24, including the boundary therebetween. A waterproofing agent, such as Performix Plasti Dip synthetic rubber coating solution manufactured by Plasti Dip International, Inc., of Blaine, Minn. is applied by brush, dipping or other suitable means prior to the attachment of the fuze assembly 60 to the grenade 120. A preferred minimum layer thickness of between about 0.001 and 0.100 inches should provide adequate sealing. Each of the exterior of the stem section 32 and the upper ledge 48 of the cap 40 are abraded or otherwise roughened prior to application of the sealing layer 136 to better guarantee adhesion. This specific agent is insoluble in water, wherein the sealing layer 136 creates a hydrophobic barrier and prevents moisture or liquid from entering the interior chamber 124 through the seam between the cap 40 and the stem section 32 of the grenade 20. In addition, an epoxy such as RTV or equivalent can be applied to the threads of the downwardly extending portion 66 of the fuze assembly 60 during manufacture to the cap 40 to prevent the possible passage or migration of moisture through the fuze assembly 60 and to the interior chamber 28 of the grenade 20.
The sealing layer 136 described herein provides a waterproof barrier enabling the grenade to be used, for example in various naval-type environments (e.g., on naval vessels). However, the operation of the grenade is substantially unaffected in that the ejection charge is still sufficient to properly eject the cap 40 and fuze assembly 60 away from the remainder of the grenade 120 prior to detonation irrespective of the presence of the coating layer.

PARTS LIST FOR FIGS. 1-9

20 grenade
24 housing or body
28 interior chamber
29 flash charge
32 stem section
36 rubberized pellets
37 lateral openings
40 cap
44 lower portion
48 upper portion
52 center opening or bore
60 fuze assembly
64 fuze body
66 downwardly extending portion
67 screw threads
70 striker
74 striker spring
78 primer
80 safety lever
90 arming or tiring pin
94 proximal ring portion
98 retaining clip
103 spring clip portion
120 grenade
124 grenade body
136 sealing layer

It will be readily apparent that other variations and modifications are possible within the intended ambits of the inventive concepts described herein, and according to the following claims:

Claims

1. A grenade comprising:

a body made from a rubberized material, said body including a hollow interior and a stem section;

a cap attached releasably to the stem section of said grenade body;

a fuze assembly threadingly attached to said cap;

an ejection charge that causes said cap and said fuze assembly to be separated from said body prior to detonation of said grenade; and

a hydrophobic sealing layer applied to the exterior of said stem section and said cap, said sealing layer providing a watertight seal relative to the interior of said grenade without substantially interfering with the ejection of said cap and fuze assembly.

2. A grenade as recited in claim 1, wherein said cap is made from plastic.

3. A grenade as recited in claim 1, wherein said waterproofing sealing layer includes a synthetic rubber.

4. A grenade as recited in claim 1, wherein said grenade is non-lethal.

5. A grenade as recited in claim 3, wherein said sealing layer is applied over a minimum thickness of about 0.001 and about 0.100 inches.

6. A method of fabricating a waterproof grenade, said method comprising the steps of:

providing a grenade body made from a rubberized material, said grenade having a hollow interior and a stem section extending therefrom;

attaching a cap to said stem section, said cap including a center opening sized for receiving a fuze assembly, said cap being releasably attached to said stem section;

applying a sealing layer to the exterior of said cap and said stem section, including an attachment boundary therebetween, said sealing layer comprising a hydrophobic material; and

attaching said fuze assembly to said cap.

7. A method as recited in claim 6, wherein said fuze assembly includes an ejection charge for jettisoning said cap from said grenade body prior to detonation of said grenade, said sealing layer being applied so as not to substantially affect the ability of said ejection charge to jettison said cap and fuze assembly from said grenade.

8. A method as recited in claim 6, wherein said fuze assembly is threadingly attached to said cap.

9. A method as recited in claim 6, wherein said cap is made from a plastic material.

10. A method as recited in claim 6, wherein said grenade is non-lethal.

11. A method as recited in claim 6, wherein said sealing layer is applied by brush.

12. A method as recited in claim 8, further including the step of applying an epoxy to the threaded connection between said fuze assembly and said cap.

13. A method as recited in claim 6, wherein said sealing layer includes a liquified synthetic rubber.

14. A method as recited in claim 13, wherein said sealing layer is applied at room temperature.

15. A method as recited in claim 6, including the additional step of roughening the surfaces of said cap and said stem section prior to said applying step.