1. Field of Invention
The present invention relates to fuzes for submunissions of the type which are disbursable by a vehicle such as a projectile or carrier shell, and in particular, to a self-destructing fuze that automatically self-destructs or self-neutralizes the submunition if the primary mode of detonation fails.
2. Description of Related Art
For many years, submunitions included in the family of Improved Conventional Munitions (ICM) employed a simple, low cost point detonating fuze for initiating a main charge upon impact. Reliability of the fuze was in the 95% range, meaning fairly large quantities of submunitions would not function for various reasons. This failure rate of about 5% presents both an environmental and a humanitarian hazard. Hazardous duds (e.g., armed but unexploded submunitions) remained on the battle field indefinitely and with potentially undesirable consequences to friendly troops and/or civilians.
The currently used M223 fuze incorporated unique and effective safety features for personnel and property protection during the manufacturing and loading process. Key among these safety features is a stabilizer ribbon attached to an arming screw that, in its engaged position, locks a detonator-containing slide in an unaligned position, thereby preventing any possible contact of a primary firing pin with the detonator. Upon deployment of the submunition from its carrier (e.g., howitzer projectile) the stabilizer ribbon becomes exposed to the air stream wind resistance and unfurls. The combination of wind resistance, induced spin of the submunition, and/or vibration causes the submunition to rotate relative to the ribbon, causing an arming screw to back out, which in turn releases a spring loaded slide that shifts, allowing the firing pin to align with the detonator. Upon impact, the firing pin, which is typically attached to a small weight, drives into the detonator causing initiation of the main charge.
In the case of projectile carrier, the entire submunition is spinning at a very high rate at ejection and the ribbon's resistance to spinning causes the arming screw to back out. However, a missile is a non-spin carrier so rotation is not available to arm the unit. Instead, the arming screw backs out because of the vibration induced as the submunition descends. That is, a loose fit between the arming screw and weight allows the arming screw to back out, which releases the spring loaded slide to align the firing pin with the detonator.
The failure of the armed submunitions described above results in hazardous duds. Incidence of death and injury to innocent victims from such hazardous duds, coupled with an international moratorium on antipersonnel mines, demonstrates a need to find a solution that would minimize these residuals on the battle field. It would be beneficial to provide a Self-Destruct Fuze (SDF) that, in the event of failure of the fuze in the primary mode, would cause a secondary action to either explode the entire submunition or at least destroy the detonator (e.g., sterilize the submunition, otherwise referred to as sterilization).
U.S. Pat. No. 5,373,790, to Chemiere, et al., discloses a mechanical system for self-destruction of a submunition, having a warhead initiated by a pyrotechnic sequence, a main striker and a priming device composed of a slide movable between a safety position and an armed position, and which has a device for priming the charge. The self-destruction system includes a secondary striker mounted inside a receptacle of the slide, and a control device that releases the secondary striker after a delay. The secondary striker is integral with a holding element held abutting a seat by the urging of an arming spring. The control device of the secondary striker has a corrosive agent stored in a glass ampoule that, when broken by the holding element, chemically attacks the holding element to release it from its seat. When the holding element is released, the arming spring moves the secondary striker to contact the detonator and destroy the munition.
U.S. Pat. No. 4,653,401, to Gatti, discloses a self-destructing fuze having a first striker member movable within the body of the fuze and able to come into contact with a detonator to cause it to explode, and a slide that is movable in a direction substantially orthogonal to the direction in which the first striker member is movable. A second striker member is disposed in the slide, and is movable from a first position in which it elastically deforms a spring and is held at a predetermined distance from the detonator, to a second position in which it comes into contact with the detonator to cause it to explode. The movement of the second striker member is delayed by a section of wire that under a force exerted by the spring is plastically deformed over time. The plastic deformation eventually frees the second striker member allowing its movement to the second position and against the detonator to cause it to explode.
U.S. Pat. No. 5,932,834, to Lyon, et al., discloses an auto-destruct fuze that provides a primary mode detonator and a delayed auto-destruct/self-neutralize mode detonator for a grenade. The mechanics for the primary mode detonator is similar to the M223 fuze. Operation of the auto-destruct/self-neutralize is based on a Liquid Annular Orifice Device (LAOD) that is released from a locked position upon expulsion of the LAOD from a storage container. The LAOD moves slowly under the urging of a spring and eventually releases a clean-up firing pin which activates a clean-up detonator to activate the primary mode detonator and destructs or self-neutralizes the grenade.
U.S. Pat. No. 4,998,476, to Rüdenauer, et al., discloses a fuze for a bomblet including a slide having a detonator triggered in response to an impact and which undergoes a transition during the free flight of the bomblet from a safe position into an armed position. The slide also includes a hydraulic or pneumatic cylinder-piston retarding device and a spring biased self-destruct pin which is operatively coupled to the device and has a self-destruct detonator associated therewith. The retarding device is freed upon movement of the slide to the armed position, and releases the movement of the self-destruct pin after a time delay to trigger the self-destruct detonator and, if needed, the primary detonator.
Numerous variations of self-destruct (SD) devices, working in conjunction with proven safety features of the stabilizer ribbon arming screw, and sliding arrangement have been developed with various degrees of success. In one variant, the SD feature centers around a microelectronic battery and circuit with a complicated attendant initiating device. Two other variants employ a critical pyrotechnic delay column to achieve the necessary time lapse. Even if successful, the critical manufacturing process and high costs of these candidates raise long term and expensive productabilty concerns.
Even with the current self-destruct fuze development, it would still be beneficial to provide reliable low-cost and improved self-destruct delay devices or mechanisms for automatically destroying or self-neutralizing submunitions after a time delay to minimize undesirable consequences to friendly troops and/or civilians. All references cited herein are incorporated herein by reference in their entireties.
In accordance with the preferred embodiments of the invention, a self-destruct fuze delay device for a submunition is provided, with the submunition having a longitudinal access, a main charge, and a detonating fuze with a movable slide for initiating the main charge upon impact. The self-destruct fuze delay device includes a detonator mounted to the fuze slide, a delay mechanism arranged within the submunition offset and substantially orthogonal to the submunition's longitudinal axis, and an activation mechanism. The delay mechanism includes an energizing source (e.g., compression spring, gas chamber), a restraining link (e.g., plunger, rod), and a self-destruct firing pin attached to the restraining link at a first portion thereof proximate to the detonator. The restraining link also has a second portion longitudinally extending from the first portion away from the detonator and attached to the fuze slide. The first portion is movable from a first position, in which it is held by it attachment to the second portion at a predetermined distance from the detonator, to a second position in which the first portion is separated from the second portion and the self-destruct firing pin is urged toward the detonator by the energizing source. The activation mechanism separates the first portion from the second portion after a predetermined delay, with the second portion remaining attached to the fuze slide after separation from the first portion.
While not being limited to a particular theory, the activation mechanism may include a container (e.g., glass ampoule) holding a fluid (e.g., acid, solution, reactant, liquid) for corroding the restraining link between the first portion and the second portion to separate the first portion form the second portion, and a breaking member (e.g., ampoule weight that impacts the container to release the fluid toward the restraining link). Moreover, this embodiment may also include a wick adjacent the restraining link at a predetermined area between the first portion and the second portion that collects the fluid from the container and isolates the collected fluid onto the predetermined area to facilitate the corroding of the restraining link. In accordance with the preferred embodiments, the detonating fuze may also have a main detonator in the fuze slide moveable between a safety position and an armed position, wherein the urging of the self-destruct firing pin toward the detonator by the energizing source causes the detonator to explode, which causes the main detonator to explode.
In another preferred embodiment of the invention, a self-destruct fuze delay device is provided, preferably for a submunition having a longitudinal axis, a main charge and a detonating fuze having a movable slide for initiating a main charge upon impact. The self-destruct fuze delay includes a detonator mounted to the fuze slide, a delay mechanism arranged within the submunition substantially orthogonal to the submunition's longitudinal axis, and an activating mechanism. The delay mechanism includes an energizing source (e.g., compression spring, pressurized gas container), a restraining link (e.g, piston, rod) having a first end attached to the self-destruct firing pin and a second end attached to the fuze slide. The restraining link is moveable from a first position, in which it is held by its attachment to the fuze slide at a predetermined distance from the detonator, to a second position in which the restraining link is separated from its attachment to the fuze slide and the self-destruct firing pin is urged toward the detonator by the energizing source. The activation mechanism separates the restraining link from its attachment to the detonating fuze slide. The activation mechanism includes a container (e.g., glass ampoule) holding a fluid (e.g., acid, solution, liquid) for corroding the restraining link, and a wick adjacent a predetermined area of the restraining link, with the wick being porous to absorb and draw the fluid from the container onto the restraining link at the predetermined area to facilitate the corroding and separation of the restraining link from attachment to the fuze slide.
While not being limited to a particular theory, the restraining link of this preferred embodiment may include a first portion proximate to the detonator, a second portion distal to the detonator and attached to the fuze slide, with the first portion and the second portion defined by the predetermined area. In this arrangement, the restraining link is separated from its attachment to the fuze slide at the predetermined area with the second portion remaining attached to the fuze slide after the separation. In the preferred embodiments, the predetermined area between the first portion and the second portion is preferably structurally weaker (e.g., undercut, thinner) than the first portion and the second portion to pulling forces along the longitudinal axis of the restraining link.
Another preferred embodiment of the invention includes a method or means for self-destructing a detonator of the submunition having a detonating fuze with a moveable slide upon deployment into the air. The method includes releasing an activation liquid from a container, absorbing the activation liquid with a porous wick, directing the absorbed activation liquid onto a predetermined area of a restraining link having a firing pin and held in place via attachment to the fuze slide, corroding the predetermined area with the directed activation liquid, separating the restraining link at the predetermined area, urging the firing pin toward the detonator, and colliding the firing pin into the detonator to destroy the detonator. The method may also include separating the restraining link at the predetermined area into a first portion having the firing pin and the second portion remaining attached to the fuze slide.
In yet another preferred embodiment of the invention, a self-destruct fuze delay device is provided, preferably for a submunition having a longitudinal axis, a main charge and a detonating fuze having a movable slide for initiating a main charge upon impact. The self-destruct fuze delay includes a detonator mounted to the fuze slide, a delay mechanism offset and substantially orthogonal to the longitudinal axis, a restraining unit movable within the movable slide, and an activation mechanism offset from the delay mechanism and supporting the restraining unit. The delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the detonator and urged toward the detonator in a first direction by the energizing source. The restraining unit is movable between a first position within the movable slide, in which the restraining unit abuts the self-destruct firing pin and holds the self-destruct firing pin away from the detonator, and a second position within the movable slide offset from the first position in a second direction in which the restraining unit allows the energizing source to move the self-destruct firing pin into the detonator. The activation mechanism supports the restraining unit in the first position against the self-destruct firing pin, and is adapted to shift after a delay and release its support of the restraining unit against the self-destruct firing pin to allow movement of the restraining unit to the position.
In still another preferred embodiment of the invention, a self-destruct fuze delay device is provided, preferably for a submunition having a longitudinal axis, a main charge and a detonating fuze having a movable slide for initiating a main charge upon impact. The self-destruct fuze delay includes a detonator mounted to the fuze slide, a delay mechanism offset and substantially orthogonal to the longitudinal axis, an activation mechanism offset from the delay mechanism, and a restraining unit movable within the movable slide. The delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the detonator and urged toward the detonator in a first direction by the energizing source. The activation mechanism includes a container holding a fluid, and a breaking member that breaks the container and accesses the fluid, which erodes the breaking member over a delay and releases a hold against the self-defense firing pin. The restraining unit is movable between a first position supported by the activation mechanism against the self-destruct firing pin to hold the self-destruct firing pin away from the detonator, and a second position that releases the hold against the self-destruct firing pin and allows the energizing source to move the self-destruct firing pin into the detonator.
Yet still another preferred embodiment of the invention includes a method or means for self-destructing a detonator of the submunition having a detonating fuze with a moveable slide upon deployment into the air. The method includes breaking a container held within the movable slide, moving a breaking member to a first position partially in the container, accessing an activation liquid in a container, eroding the breaking member with the activation liquid, moving the breaking member to a second position further into the container, shifting a restraining unit within the movable slide, releasing a firing pin toward the detonator, and colliding the firing pin into the detonator to initiate the detonator and destroy the submunition.
The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:
Exemplary embodiments for a self-destruct fuze delay device are described with reference to
The time required for the activation fluid to react with the restraining link and achieve failure at the predetermined location of the restraining link is the predetermined time necessary to satisfy desired delay requirements for the self-destruct fuze. The primary fuze also retains the positive operation of the M223 fuze, that is, it utilizes the stabilizer ribbon, firing pin and slide to retain the known out-of-line safety features.
Although the preferred self-destruct fuze delay device is applicable to all the various ICM items, in the interest of brevity, the exemplary self-destruct fuze devices are generally tailored toward use in the Guided Multiple Launch Rocket System (GMLRS). The GMLRS warhead typically contains 404 submunitions, each with its own self-destruct (SD) fuze. While not being limited to a particular theory, the submunitions typically are disbursed via a center core burster that explodes in flight creating ample pressure to burst the warhead casing, and allowing the currently-used submunition's random dispersion into the atmosphere.
In general, as each submunition is disbursed into the atmosphere, the impact of the air stream causes the submunition's stabilizer ribbon to unfurl, allowing an arming screw to back out and a slide to move to its armed position. Upon impact, the firing pin is free to pierce the primary detonator and cause a subsequent main charge explosion, which destroys the submunition. Damaged fuzes and fuzes that arm properly but come into contact with the ground or a target via side impact may fail to initiate the main charge resulting in residual hazardous duds. A hazardous dud is a submunition that still has its fuze attached and its primary detonator present that together could potentially initiate the main charge. A hazardous dud is different than an unexploded ordinance, which is a submunition that has no means of initiation (e.g., primary detonator is missing or destroyed).
The delay necessary for the activation liquid to corrode the restraining link to failure (e.g., about 25 seconds minimum to 30 minutes) is greater than the foreseeable flight time of the submunition, which ends when the submunition reaches the ground or target. This delay allows the primary detonator to initiate the main submunition charge when the submunition strikes the ground or target. The self-destruct fuze delay device is designed to destroy the submunition if the submunition fails to explode after it strikes the ground or target.
Other advantages, characteristics and details of the invention will emerge from the explanatory description thereof provided below with reference to the attached drawings and examples, but it should be understood that the present invention is not deemed to be limited thereto. Toward that end,
Still referring to
If the detonating fuze 14, which includes the primary detonator 18, the slide 16, and the primary striker 20, functions normally, the submunition 12 explodes and the SD fuze delay device 10 is destroyed in the process. If the detonating fuze 14 functions normally to the point that the slide 16 moves into its armed position, but the submunition 12 fails to explode, the SD fuze delay device 10 will initiate the primary detonator 18 and, in turn, will then fire the main charge to explode the submunition. If the detonating fuze 14 does not function normally so that the slide 16 remains in the safety position or does not reach the armed position, then the SD fuze delay device 10 will initiate the primary detonator 18 but likely not the main charge, resulting in a sterilized submunition or unexploded ordinance.
Referring in particular to
While not being limited to a particular theory, the axial rod 36 includes a weakened area 48 that defines a first portion 50 and a second portion 52 of the restraining link 26. The first portion 50 is proximate or adjacent to the secondary detonator 22 and includes the secondary firing pin 28, the piston 34 and part of the axial rod 36 extending from the piston. The second portion 52 is distal or away from the secondary firing pin 28 and is fixedly attached to the slide 16 via the retainer pin 40. The weakened area 48 is a predetermined part of the axial rod 36 that is constructed weaker than the remainder of the axial rod to fail upon application of a reactant (e.g., corrosive agent, acid, solution) and release the first portion 50 toward the secondary detonator 22. For example, the weakened area may include a circumferential plane or ring section that is undercut (e.g., having walls thinner than the walls of the adjacent first and second portions). Furthermore, a wick 54 is positioned adjacent, and preferably encircles the weakened area 48. The wick 54 is made of a porous material that absorbs the reactant fluid and directs it to the weakened area 48 to facilitate the corrosion of the restraining link 26 at the weakened area, as is described, for example, in greater detail below.
As can best be seen in
The activation mechanism 25 also includes an ampoule weight 60, a compression spring 62 and a spring retainer clip or pin 64. In the exemplary embodiment of
Upon deployment of the submunition 12, the self-destruct fuze delay device 10 self-destructs the submunition after a preset delay if the submunition fails to explode upon its impact with the ground or a target.
Upon its release, the compression spring 62 drives the ampoule weight 60 into the container 56, breaking the container and releasing the reactant fluid 58 to flow into and be absorbed by the felt wick 54. To help facilitate the flow of the released fluid 58 to the wick 54, a channel is provided therebetween and preferably the ampoule weight 60 acts as a plunger and pushes the fluid through the channel to the wick. In other words, after breaking the container 56, the compression spring 62 continues to drive the ampoule weight 60, forcing the fluid 58 into the wick 54. At this time, the delay mechanism 24 appears as depicted in
The wick 54 encircles the weakened area 48 of the restraining link 26 allowing the reactant fluid 58 (e.g., activation liquid) to communicate with and attack (e.g., corrode) the axial rod 36 at the weakened area 48.
Output from the exploded secondary detonator 22 initiates the adjacent primary detonator 18, causing it to explode and sterilize the submunition. If at this time the fuze slide 16 is in its armed position, such that the primary detonator 18 is aligned with the main charge, then the initiation of the primary detonator from the secondary detonator 22 will then fire the submunition 12. Accordingly, the SD fuze delay device 10 is reliable since it ensures either sterilization or destruction of the submunition 12 depending on the relationship between the primary detonator 18 and the main charge.
As noted above, the explosion of the secondary detonator 22 activates the primary detonator 18, causing it to explode and set off the main charge if the primary detonator is aligned therewith. Preferably, the secondary detonator 22 remains adjacent the primary detonator 18 regardless of the position of the primary detonator to ensure that output from an explosion of the second detonator initiates the primary detonator. This ensures one of the previously discussed potential outcomes upon dispersion of the submunition into the atmosphere.
Still referring to
The axial rod 110 extends away from the secondary detonator 22 from the secondary firing pin 28, freely passes inside the compression spring 30 and is attached at its distal end 38 to the closure plate 122 of the fuze slide 16 via the restraining link 114 as set forth in greater detail below. The axial rod 110 and compression spring 30 are partially embedded in a cylindrical sleeve 124 of the piston 112, which extends away from the secondary firing pin 28 to form the cylindrical sleeve having a central bore that partially houses the axial rod and compression spring 30 therein. The compression spring 30 is mounted in a compressed state around the axial rod 110 and is positioned between the piston 112 and the closure plate 122 of the fuze slide 16 to urge the piston, and thus the axial rod and the secondary firing pin 28 toward the secondary detonator 22. As can best be seen in
While not being limited to a particular theory, the restraining link 114 holds the axial rod 110 to the closure plate 122. The restraining link 114 is preferably a styrene based (e.g., polystyrene) shaft embedded and sealed (e.g., adhesively, frictionally) to aligned counter bores 126, 128 in the closure plate 122 and the axial rod 110, respectively. As such, the restraining link 114 is a weakened area that fails under chemical attack and breaks to release the firing pin and axial rod 110 from the closure plate 122. When broken, the restraining link 114 separates into two sections, which define adjacent edges of first and second portions 130, 132 of the restraining link. The first portion 130 is attached to the axial rod 110 which is attached to the secondary firing pin 28. The second portion 132 is distal or away from the secondary firing pin 28 and is attached to the closure plate 122.
The restraining link 114 is constructed of a material vulnerable to a reactant (e.g., corrosive agent, acid, solution), in particular, in comparison to the other elements of the delay mechanism 104 discussed above, to fail over time under application of the reactant. While not being limited to a particular theory, the reactant erodes the restraining link 114, causing the restraining link fail or break under the pulling stress of the compression spring 30 and release the first portion 130 toward the secondary detonator 22 (
Still referring to
The activation mechanism 106 also includes an ampoule breaker 134, a compression spring 62 and a spring retainer pin 136. As shown in
Like the ampoule weight 60 described above, the ampoule breaker 134 is a breaking member that, but for the spring retainer pin 136, is urged by the compression spring 62 into impact with the container 56, causing the container to break and release the reactant fluid 58. In addition to breaking the container 56, the ampoule breaker 134 also preferably acts as a plunger and pushes the released fluid 58 toward the delay mechanism 104 whereupon the fluid corrodes the restraining link 114 to release the secondary firing pin 28 toward the secondary detonator 22 (
In a preferred embodiment, such as exemplified in
The self-destruct fuze delay device 100 self-destructs the submunition 12 after a preset delay if the submunition fails to explode upon its impact with the ground or a target.
The extraction of the safety lockout pin 46 removes the lockout from the delay mechanism 104, and the extraction of the spring retainer pin 136 releases the compression spring 62. Upon its release at Step 204, the compression spring 62 drives the ampoule breaker 134 into the container 56, breaking the container and releasing the reactant fluid 58 to flow to the restraining link 114, preferably via the wick 54. To help facilitate the flow of the released fluid 58 to the wick 54 and restraining link 114, a liquid passage 158 within the aperture 108 is provided therebetween.
As can best be seen in
The wick 54 encircles an area (e.g., weakened area) of the restraining link 114, and directs the reactant fluid 58 to access and attack (e.g., erode, corrode) the restraining link at Step 208. Preferably the fluid 58 erodes the restraining link in contact with the wick 54. In other words, the axial rod 110, the piston 112, the compression spring 30 and the secondary firing pin 28 are preferably made of metal and not vulnerable to erosion by the reactant fluid 58.
At Step 210, over a predetermined time period (e.g., between about 25 seconds and 30 minutes the restraining link 114 exposed to the reactant fluid 58 weakens to a point of failure and breaks, thus defining the first and second portions 130, 132. The predetermined time period typically varies in accordance with several factors, for example, the composition of the reactant fluid, the density of the restraining link and the ambient temperature, as would be readily understood by a skilled artisan. For example, at cold temperatures of about −25° F., the restraining link fails at about 20 to 29 minutes. Of course the failure time decreases as the temperature increases.
Upon the failure of the restraining link 114 at Step 212, the compression spring 30 drives the first portion 130 of the restraining link 114, the piston 112, the axial rod 110 and the secondary firing pin 28 toward the secondary detonator 22, causing the secondary firing pin to impact and explode the secondary detonator 22. See, for example,
As can best be seen in
The delay device 300 further includes an activation mechanism 306 offset and in communication with the delay mechanism 304 via a first channel 308. After deployment and a subsequent delay typically resulting from the failure of an armed submunition, the activation mechanism 306 activates the delay mechanism 304, which causes the secondary detonator 22 to explode. As noted above, the explosion of the secondary detonator 22 activates the primary detonator 18, causing it to explode and set off the main charge if the primary detonator is aligned therewith. Preferably, the secondary detonator 22 remains adjacent the primary detonator 18 regardless of the position of the primary detonator to ensure that output from an explosion of the secondary detonator initiates the primary detonator. This ensures one of the previously discussed potential outcomes upon dispersion of the submunition into the atmosphere.
Still referring to
The compression spring 30 is mounted in a compressed state between the wall 322 of the secondary firing pin 314 and the closure plug 310 of the fuze slide 16 to urge the secondary firing pin toward the secondary detonator 22. Before deployment, the sloped wall 326 abuts an interlock ball 330 aligned within the first channel 308 in the fuze slide 16. As can best be seen in
While not being limited to a particular theory, the activation mechanism 306 is located in a third channel 362 offset from the second channel 32 that houses the delay mechanism 304. The activation mechanism 306 includes a glass ampoule as a container 56 that holds a reactant fluid 58. The reactant fluid 58 is a corrosive agent (e.g., acid or liquid solution) that chemically attacks and causes certain materials (e.g., hard plastics) to erode over time. Preferably the glass ampoule is partially housed in a generally cup-shaped resilient insulator 332 that is preferably not susceptible to the reactant fluid so that the reactant fluid 58 does not erode the container 56. The insulator 332 also provides a benefit similar to the closure plug 310, since the insulator seals the container 56 and other elements of the activation mechanism 306 within the slide 16. Since the container 56 is breakable, it is beneficial to include the insulator 332 about the container to absorb the vibrations and prevent the container from moving and breaking prematurely. Accordingly, the insulator 332 is not required for the operation of the invention, but is helpful to protect the container 56.
The activation mechanism 306 further includes the ampoule breaker 334, a compression spring 62 and an activation pin 336. Like the ampoule weight 60 and the ampoule breaker 134 described above in other preferred embodiments, the ampoule breaker 334 is a breaking member that, but for the activation pin 336, is urged by the compression spring 62 into impact with the container 56, causing the container to break and release the reactant fluid 58.
The ampoule breaker 334 is a breaking member that includes a timing ball 338 and a piston 340 held in contact by a clamp 342. The clamp 342 is made of metal or other hard material that preferably is at least substantially impervious to erosion by the reactant fluid 58. As can be seen, for example, in
Referring to
As noted above, the ampoule breaker 334 and compression spring 62 are aligned with the container 56 in the third channel 362 of the fuze slide 16 that is offset from the second channel 32 and in communication with the first channel 308. The compression spring 62 is an energizing source mounted in a compressed state inside the ampoule breaker 334 between an inner wall 364 of the sleeve member 358 and a shoulder 366 of the slide 16. When inserted into the fuze slide 16 as shown in
The timing ball 338 is seated in the aperture 350 of the first supporting wall 348 and abuts the axial rod 356, as both the timing ball and the piston 340 are held together by the clamp 342. Initially, the timing ball 338 is sized and structurally hard enough to remain seated, that is, not slide through the aperture 350 when urged by the compression spring 62, and is sufficiently hard to impact and break the container 56. As discussed above, the container 56 (e.g., glass ampoule) is breakable upon collision with a projecting member, for example, the timing ball 338 when the timing ball is pushed into the container by the compression spring 62.
While not being limited to a particular theory, the timing ball 338 is both a part of the breaking member that breaks the container 56 upon collision, and a weakened area of the self destruct fuze delay device 300 that erodes under chemical attack and, after a delay, slips through the aperture 350 and allows the interlock ball 330 to release the secondary firing pin 314, as set forth in greater detail below. As such, the timing ball 338 is constructed of a material, preferably styrene (e.g., polystyrene) that is both hard enough to break glass and is vulnerable to the reactant 58 (e.g., corrosive agent, acid, solution). In particular, the timing ball 338 is vulnerable to the reactant 58, in comparison to the other elements of the activation mechanism 306 discussed above, to fail over time under application of the reactant. As can best be seen in
The self-destruct fuze delay device 300 self-destructs the submunition 12 after a preset delay if the submunition fails to explode upon its impact with the ground or a target.
The fuze assembly 302 of the fuze delay device 300 is mountable on the submunition 12, and includes a ribbon retainer 372 and a stabilizer ribbon 374. The ribbon retainer 372 is preferably a thin plastic slide lock that holds both the stabilizer ribbon 374 and the fuze slide 16 in place prior to deployment of the submunition 12. That is, the ribbon retainer 372 prevents premature unfurling of the stabilizer ribbon 374, and also prevents premature movement of the fuze slide 16 from its safe position (as shown for example in
As can be seen in
While not being limited to a particular theory, the activation pin 336 may be structured as a single solid generally cylindrical shaft that is bent to form a hook. As an alternative, the activation pin 336 may be structured with more than one shaft strand (e.g., two shaft strands) similar to a bent hair pin. Forming the activation pin 336 with, for example, two shaft strands, allows the activation pin to be formed with less material and easily bent into shape. It is understood that the thickness and construction of the activation pin is not critical to the invention, as long as the pin works for its purpose of holding the axial rod 356 in places when inserted into the annular groove 360, and of being removable from the annular groove upon extraction by the ribbon retainer 372.
The extraction of the activation pin 336 frees the compression spring 62. Upon its release, the compression spring 62 drives the ampoule breaker 334 into the container 56, breaks the container and exposes the timing ball 338 to the reactant fluid 58 at Step 404. This exposure initiates a reaction causing an erosion of the timing ball at Step 406. As can best be seen in
At Steps 404 and 406, the fuze delay device 300 appears, for example, in
In the case of projectile carrier, the entire submunition is spinning at a very high rate at ejection. While not being limited to a particular theory, the wind resistance of the air stream tends to cause the unfurled stabilizer ribbon 374 to resist the rotational spinning of the submunition 12. This resistance to rotation is transferred to the arming screw 378, causing the arming screw to rotate against the spinning submunition 12 and back out from its typical pre-deployment position that locks the fuze slide 16 in its safe position. Preferably the backing out of the arming screw 378 from its pre-deployment position releases the fuze slide to move, under the rotational forces of the deployed submunition, to its armed position, as readily understood by a skilled artisan. However, not all submunitions are spinning projectile. For example, as discussed above, a missile is a non-spin submunition; meaning that rotation is not available to arm a deployed missile. Instead, the arming screw backs out because of the vibration induced as the submunition descends. That is, a loose fit between the arming screw and its housing, along with the screw's weight allows the arming screw to back out, which releases the spring loaded slide to align the firing pin with the detonator, as readily understood by a skilled artisan. Regardless of their spinning characteristics, submunitions are designed so that when the munition is designed to explode (e.g., upon impact with its target), the main striker 20 with weight inertia initiates the primary detonator 18, causing a chain of explosions through the lead and main charges that destroys the submunition. In the preferred embodiments, the sequence of events described in this paragraph, from the arming screw 378 releasing the fuze slide 16 to the destruction of the submunition, occurs during the reaction between the timing ball 338 and the reactant fluid 58. In other words, if the submunition 12 works as normally intended, the chain of explosions will destroy the submunition while the reactant fluid 58 erodes the timing ball 338.
However, if the submunition does not function normally, that is, explode upon hitting its target; the reactant fluid continues to erode the timing ball 338 (
As the timing ball 338 erodes to a size small enough to fit through the aperture 350, the force of the compression spring 62 pops the timing ball through the aperture at Step 408. As can be seen in
Accordingly, the movement of the timing ball 338 and the piston 340 in step 408 releases the secondary firing pin 314. At Step 410, the compression spring 30 drives the released secondary firing pin 314 toward the secondary detonator 22, causing the secondary firing pin to impact and explode the secondary detonator 22. See, for example,
It is understood that the method and mechanism for making and using the self-destruct fuze delay device described herein are exemplary indications of preferred embodiments of the invention, and are given by way of illustration only. It other words, the concept of the present invention may be readily applied to a variety of preferred embodiments, including those disclosed herein.
While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. For example, the SD fuze delay device is applicable to all the various ICM items including the submunitions of the non-rotating GMLRS/MLRS warheads. For non-rotating submunitions, deployment into the air stream induces vibration sufficient to cause the arming screw to back out, allowing the fuze slide to move into the armed position. Accordingly and preferably, upon deployment of rotating or non-rotating submunitions into the atmosphere, the ribbon unfurls, the safety and retainer pins extract, and the fuze slide moves to its armed position. Moreover, while the wicks are shown encircling the weakened area of the restraining link, it is understood that such preferred relationship is not required, as long as the wick is adjacent the weakened area to expedite the desired failure. As another example, the timing ball 338 could be coupled or integral with the piston 340, and the container 56 or insulator 332 constructed to restrict movement of the timing ball upon collision with the container to an opening about the size of the aperture 350; that is, having a diameter smaller than the diameter of the timing ball. In this example, the timing ball 338 does not pop through the opening and into the container 56 until the reactant fluid 58 erodes the timing ball to a size that allows passage through the opening. Without further elaboration, the foregoing will so fully illustrate the invention that other may, by applying current or future knowledge, readily adapt the same for use under various conditions of service.
This utility application is a Continuation-in-Part application of, and claims the benefit under 35 U.S.C. §120 of application Ser. No. 11/383,116 filed on May 12, 2006 entitled SELF-DESTRUCT FUZE DELAY MECHANISM and whose entire disclosure is incorporated by reference herein.
Number | Name | Date | Kind |
---|---|---|---|
2454281 | Hicks | Nov 1948 | A |
2641185 | Lockett | Jun 1953 | A |
2669929 | Shull et al. | Feb 1954 | A |
2741182 | Faust et al. | Apr 1956 | A |
2779276 | Clary, Jr. | Jan 1957 | A |
3779168 | Hinely et al. | Dec 1973 | A |
3792663 | Schneider, Jr. | Feb 1974 | A |
4653401 | Gatti | Mar 1987 | A |
4998476 | Rudenauer et al. | Mar 1991 | A |
5373790 | Chemiere et al. | Dec 1994 | A |
5932834 | Lyon et al. | Aug 1999 | A |
Number | Date | Country | |
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20070261585 A1 | Nov 2007 | US |
Number | Date | Country | |
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Parent | 11383116 | May 2006 | US |
Child | 11616625 | US |