US20120037028A1 - Stationary self-destruct fuze mechanism - Google Patents
Stationary self-destruct fuze mechanism Download PDFInfo
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- US20120037028A1 US20120037028A1 US12/855,997 US85599710A US2012037028A1 US 20120037028 A1 US20120037028 A1 US 20120037028A1 US 85599710 A US85599710 A US 85599710A US 2012037028 A1 US2012037028 A1 US 2012037028A1
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- Prior art keywords
- self
- destruct
- fuze
- slide
- detonator
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
- F42C9/00—Time fuzes; Combined time and percussion or pressure-actuated fuzes; Fuzes for timed self-destruction of ammunition
- F42C9/14—Double fuzes; Multiple fuzes
- F42C9/16—Double fuzes; Multiple fuzes for self-destruction of ammunition
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
- F42C15/00—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges
- F42C15/38—Arming-means in fuzes; Safety means for preventing premature detonation of fuzes or charges wherein arming is effected by chemical action
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F42—AMMUNITION; BLASTING
- F42C—AMMUNITION FUZES; ARMING OR SAFETY MEANS THEREFOR
- F42C9/00—Time fuzes; Combined time and percussion or pressure-actuated fuzes; Fuzes for timed self-destruction of ammunition
- F42C9/08—Time fuzes; Combined time and percussion or pressure-actuated fuzes; Fuzes for timed self-destruction of ammunition the timing being caused by chemical action, e.g. of acids
Definitions
- 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.
- 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.
- the stabilizer ribbon 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.
- the firing pin which is typically attached to a small weight, drives into the detonator causing initiation of the main charge.
- U.S. Pat. No. 5,373,790 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.
- 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.
- LAOD Liquid Annular Orifice Device
- U.S. Pat. No. 4,998,476, to Haidenauer, 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.
- SD self-destruct
- U.S. Pat. No. 7,530,313 to Chamlee, et al. discloses a submunition having a slide that houses a self-destruct fuze delay.
- the delay includes a container filled with an activation fluid, a spring-loaded ampoule breaker to break the container upon deployment of the munition, a spring-loaded self-destruct firing pin to initiate a secondary detonator in close proximity to a primary detonator, and an interlock ball supported by the ampoule breaker that locks the self-destruct firing pin away from the secondary detonator.
- the ampoule breaker includes a piston and a timing ball, which accesses the activation liquid.
- the action of the activation liquid on the timing ball over time causes the timing ball to erode until it is forced into the container by the spring-loaded piston.
- the movement of the piston frees the interlock ball, allowing the spring-loaded self-destruct firing pin to move under force and impact or initiate the secondary detonator.
- Initiation of the secondary detonator destroys the primary detonator and, depending upon slide location, either sterilizes the submunition, or destroys the entire submunition.
- the preferred embodiments include a self-destruct detonating fuze for a submunition having a longitudinal axis, a main charge and the self-destruct detonating fuze for initiating the main charge upon impact.
- the exemplary self-destruct detonating fuze includes a self-destruct slide housing holding a first detonator, a movable fuze slide slidingly engaged with the self-destruct slide housing between a safe position and an armed position with the movable fuze slide having a second detonator mounted thereto, and a slide housing holding member permanently engaged with the self-destruct slide housing and holding the self-destruct slide housing in a stationary position relative to the submunition regardless of the position of the movable fuze slide.
- This stationary self-destruct slide housing includes a delay mechanism, an interlock unit and an activation mechanism.
- the delay mechanism is offset and substantially orthogonal to the longitudinal axis of the submunition.
- the delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the first detonator and urged toward the first detonator in a first direction by the energizing source to explode the first detonator.
- the interlock unit is movable between a first position within the self-destruct slide housing, in which the interlock unit abuts the self-destruct firing pin and restrains the self-destruct firing pin away from the first detonator, and a second position within the self-destruct slide housing offset from the first position in a second direction in which the interlock unit allows the energizing source to move the self-destruct firing pin into the first detonator.
- the activation mechanism is offset from the delay mechanism and supports the interlock unit in the first position against the self-destruct firing pin.
- the activation mechanism is adapted to shift after a delay and release its support of the interlock unit against the self-destruct firing pin to allow movement of the interlock unit to the second position.
- the preferred embodiments also include a self-destruct detonating fuze for a submunition having a longitudinal axis, a main charge and the self-destruct detonating fuze for initiating the main charge upon impact.
- the self-destruct detonating fuze includes a self-destruct slide housing holding a first detonator, a movable fuze slide slidingly engaged with the self-destruct slide housing between a safe position and an armed position with the movable fuze slide having a second detonator mounted thereto, and a slide housing holding member permanently engaged with the self-destruct slide housing and holding the self-destruct slide housing in a stationary position relative to the submunition regardless of the position of the movable fuze slide.
- This stationary self-destruct slide housing also includes a delay mechanism, an interlock unit and an activation mechanism.
- the delay mechanism is offset and substantially orthogonal to the longitudinal axis.
- the delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the first detonator and urged into the first detonator by the energizing source.
- the activation mechanism is offset from the delay mechanism, and 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-destruct firing pin.
- the interlock 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 first 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 first detonator.
- the self-destruct slide housing includes a channel between the delay mechanism and the activation mechanism, and the interlock unit includes at least one interlock ball that moves within the channel between the first position and the second position.
- the preferred slide housing holding member includes a fuze housing.
- the fuze housing is fixedly secured to the submunition and covers the stationary self-destruct slide housing.
- the fuze housing includes a slide housing locking unit extending around and holding the self-destruct slide housing in the stationary position relative to the submunition.
- the slide housing holding member preferably further includes an arming screw received within an aperture of the stationary self-destruct slide housing. The aperture is aligned between the arming screw and the second detonator when the movable fuze slide is in the armed position. While not considered a primary function of the arming screw, it is contemplated that the arming screw may also retain the self-destruct slide housing in the stationary position relative to the submunition.
- FIG. 1 is a top sectional view of an exemplary stationary self-destruct fuze mechanism according to the preferred embodiments
- FIG. 2 depicts the fuze mechanism shown in FIG. 1 from a side sectional view
- FIG. 3 is a perspective view of the exemplary stationary self-destruct fuze mechanism prior to loading into a carrier
- FIG. 4 is an exploded view of the exemplary stationary self-destruct fuze mechanism
- FIG. 5 is a perspective view of the stationary self-destruct slide housing
- FIG. 6 is a perspective view of the stationary self-destruct slide housing underside
- FIG. 7 is a perspective view of the movable fuze slide
- FIG. 8 is a side view of the exemplary stationary self-destruct fuze mechanism and partial side view of the attached charge before deployment into the atmosphere;
- FIG. 9 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism shown in FIG. 1 after deployment;
- FIG. 10 is a side view partially in section of the exemplary fuze delay device shown in FIG. 9 ;
- FIG. 11 is a side view of the timing ball and ampoule cup shown in FIGS. 9 and 10 ;
- FIG. 12 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism of FIG. 1 after erosion of the timing ball;
- FIG. 13 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism of FIG. 1 after release of the restraining unit and fuze slide in an armed position;
- FIG. 14 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism of FIG. 1 after release of the restraining unit and fuze slide not in the armed position;
- FIG. 15 is a flow diagram depicting an exemplary sequence of events for the destruction of the fuze mechanism.
- SSD stationary self-destruct
- the exemplary SSD fuze mechanisms are generally tailored toward use in the M864, M155 MM projectile which contains 72 submunitions, each with its own SSD fuze. While not being limited to a particular theory, the submunitions typically are disbursed via an expulsion charge that explodes in flight creating ample internal pressure to shear the base plate threads and expel the cargo out the rear of the projectile and into the atmosphere.
- 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 SSD fuze mechanisms of the preferred embodiments incorporate a predetermined time delay (e.g., about 25 seconds minimum to about 5 minutes) that is greater than the foreseeable flight time of the respective 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 SSD fuze mechanisms destroy the submunition or sterilize the fuze if the submunition fails to explode after it strikes the ground or target.
- the fuze also retains the positive operation of the M223/M239 fuze, that is, it utilizes the stabilizer ribbon, arming screw and slide to retain the known out-of-line safety features.
- FIGS. 1-15 depict an exemplary stationary self-destruct (SSD) fuze 10 as part of a SSD fuze mechanism 12 for a submunition, as readily understood by a skilled artisan.
- the SSD fuze 10 includes a stationary self-destruct slide housing 14 slidingly engaged with a movable fuze slide 16 of the fuze mechanism 12 .
- the movable fuze slide 16 holds a primary detonator 18 that shifts with the slide between a safety position ( FIGS.
- FIGS. 9 , 10 where the primary detonator is aligned with the arming screw preferably along the longitudinal axis of the submunition between the arming screw and the submunition.
- the slide holding members 28 in this exemplary embodiment extend from a fuze housing 30 as metal fingers bending down and about the SSD slide housing 14 .
- the fuze housing is preferably made of metal and maintains the slide housing in its stationary position relative to the submunition regardless of the position of the movable fuze slide 16 .
- the fuze housing 30 includes a first side wall 32 and opposing second side wall 34 that abut and hold a first lengthwise wall 36 and second lengthwise wall 38 of the SSD slide housing 14 , while the slide holding members 28 abut and hold a first width side wall 37 and opposing second width side wall 39 , of the SSD slide housing.
- the side walls 32 , 34 and holding members 28 combine to rigidly secure and protect the SSD slide housing 14 stationary relative to the submunition. This is especially beneficial to protect the internal components (e.g., movable fuze slide 16 , detonators 18 , 40 , arming screw 20 , delay mechanism 22 , activation mechanism 24 , interlock unit 26 ) from damage from severe premature impacts.
- the internal components e.g., movable fuze slide 16 , detonators 18 , 40 , arming screw 20 , delay mechanism 22 , activation mechanism 24 , interlock unit 26 .
- the delay mechanism 22 of the SSD fuze 10 includes a self-destruct (SD) detonator 40 that is arranged in a first channel 42 of the SSD slide housing 14 offset and substantially orthogonal to the longitudinal axis of the submunition and to the arming screw 20 .
- a self-destruct detonator retainer 44 preferable formed of a plastic or metal secured (e.g., by adhesives, crimping, friction, heat) to an inner-cylindrical wall 46 of the channel 42 to seal the self-destruct detonator 40 within the channel.
- the delay mechanism 22 also includes a compression spring 46 as an energizing source, and a self-destruct (SD) firing pin 48 , both preferably formed of metal or other hard material and located within the first channel 42 .
- the SD firing pin 48 includes a front end 50 proximate the self-destruct detonator 40 and a spring holding rod section 52 . While not being limited to a particular theory, the rod section 52 prior to deployment extends through a reduced diameter 54 of the first channel 42 at the second width side wall 39 of the SSD slide housing 14 , where it is held in place by a firing pin safety clip 56 , as would readily be understood by a skilled artisan. In this arrangement shown in FIG. 2 , the firing pin clip 56 holds the firing pin compression spring 46 in a state of tension between the front end 50 of the firing pin and an interior shoulder wall 58 of the first channel 42 .
- the firing pin safety clip 56 slides about a narrowed portion 60 of the rod section 52 between a distal end 62 of the SD firing pin 48 ( FIG. 10 ) and the second with side wall 39 of the SSD slide housing 14 .
- the SD firing pin 48 is aligned with the SD detonator 40 and movable along the first channel 42 to explode the detonator upon release of the SD firing pin and the compression spring 46 as described by example in greater detail below.
- the interlock unit 26 is shown in FIG. 2 as including as part of a restraining unit that secures the SD firing pin 48 during a predetermined delay away from the SD detonator 40 . While not being limited to a particular theory, the interlock unit 26 includes at least one, and preferable two interlock balls 64 , 66 housed within an adjoining channel 68 of the SSD slide housing 14 between the first channel 42 of the slide housing and a second channel 70 of the slide housing.
- the adjoining channels 68 is shown substantially orthogonal to the generally parallel directions of the first and second channels 42 , 70 , that the angle of the adjoining channel is not so limited and may be exactly orthogonal, acute or obtuse to the direction of the first and second channels within the scope of the invention.
- the preferred interlock unit 26 includes two interlock balls 64 , 66 , that the interlock unit is also not limited to the two balls, as the unit may include more or fewer balls, or one or more alternatively shaped members that are movable within the adjoining channel 68 and that extend from the activation mechanism 24 to restrict movement of the firing pin 48 for a predetermined self-destruct time after deployment of the submunition.
- the activation mechanism 24 is offset from the delay mechanism 22 and supports the interlock unit 26 in a position that restricts movement of the SD firing pin 48 toward the SD detonator 40 .
- the activation mechanism is adapted to shift after a time delay and release its support of the interlock unit against the self-destruct firing pin to allow movement of the interlock unit to a position that frees the firing pin to explode the SD detonator.
- the activation mechanism 24 is located in the second channel 70 , which is offset from the first channel 42 that houses the delay mechanism 22 .
- the activation mechanism 24 includes a breakable container 72 (e.g., glass ampoule, ceramic ampoule) that holds a reactant fluid 74 .
- the reactant fluid 74 is preferable a corrosive agent (e.g., acid or liquid solution) that chemically attacks and causes certain materials (e.g. hard plastics) of the interlock unit 26 to erode over time.
- the container 72 is partially housed in a generally cup-shaped ampoule cup 76 that is a resilient insulator preferably not susceptible to the reactant fluid 74 so that the reactant fluid does not erode the ampoule cup if it inadvertently leaks out of the container.
- the resilient insulative ampoule cup 76 seals the container 72 and other elements of the activation mechanism 24 discussed below within the second channel 70 of the SSD slide housing 14 .
- the container 72 is sealed inside the ampoule cup 76 preferably with an epoxy, and then secured inside the second channel 70 as a unit.
- the ampoule cup 76 also contains the orifice (e.g., ampoule cup aperture 94 ) through which the timing ball 90 must pass to release the self-destruct firing pin 48 , as discussed in greater detail below.
- the activation mechanism 24 further includes a breaking member (e.g., timing ball) 78 , an activation pin 80 , and an activation pin compression spring 82 , which is shown in FIG. 2 as being held in a compressed state by a self-destruct (SD) activation clip 84 . That is, the SD activation clip 84 slides about a decreased diameter portion 86 of the activation pin 80 between a distal end 88 of the activation pin and the outer force of the second width sidewall 39 of the SSD slide housing 14 .
- a breaking member e.g., timing ball
- the breaking member 78 is an ampoule breaker that upon release of the SD activation clip 84 is urged by the compression spring 82 into impact with the container 72 , causing the container to break and release the reactant fluid 74 into communication with the breaking member.
- the breaking member is a timing ball 90 made of a hard plastic or similar material that is hard enough to break glass or similar fragile material (e.g., ceramic), and that erodes when exposed to the reactant fluid 74 .
- a resilient sleeve 92 centers the timing ball 90 in the second channel 70 and keeps the timing ball aligned between the glass ampoule and the activation pin 80 .
- the ampoule cup 76 preferably includes a semi-closed end with an aperture 94 facing the timing ball 90 .
- the aperture 94 in the ampoule cup is large enough to allow direct contact between the timing ball 90 and the container 72 (e.g. glass ampoule), but is small enough to still prevent the ball from passing through until the reactant fluid has reduced the diameter.
- the exemplary ampoule cup aperture 94 is not completely circular, but is shaped to include aperture grooves 96 for allowing the reactant fluid 74 access to the side and back ends of the timing ball 90 . That is, the aperture grooves 96 allow the reactant fluid to seep to the outer surfaces of the timing ball for greater coverage of the ball beyond the aperture 94 .
- the timing ball 90 would emulate a plug and prevent the reactant fluid 74 from coating and dissolving the surface of the timing ball.
- the aperture 94 and breaking member 78 preferably have different shapes at their intersection to allow fluid bypass through their meeting. It is understood that the aperture 94 is not limited by shape or size by the aperture shown in FIG. 11 .
- the ampoule cup aperture 94 or its equivalents, such as a metal member placed between the container 22 and timing ball 90 , provide a means for permitting fluid communication between the timing ball and the reactant fluid 74 .
- the activation pin 80 is a generally rod-shaped metal unit that holds the breaking member 78 against the ball guide 92 before deployment.
- the activation pin 80 includes an enlarged diameter section 98 that abuts the compression spring 82 , and a proximal section 99 between the enlarged diameter section 98 and the timing ball 90 .
- the activation pin 80 is urged by the compression spring 82 toward the fragile container 72 , pushing the breaking member 78 at least partially past the ampoule cup aperture 94 at the semi-closed end of the ampoule cup 76 into the container 72 , breaking the container and releasing the reactant fluid 74 onto the breaking member 78 .
- the SD activation clip 84 holds the compression spring 82 in a state of tension between the enlarged diameter section 98 of the activation pin 80 and an interior wall 100 of the SSD slide housing 14 .
- the enlarged diameter section 98 also abuts and supports the interlock unit 26 to its first position where the interlock unit prevents the self-destruct firing pin 48 from moving into and exploding the self-destruct detonator 40 .
- the breaking member 78 , activation pin 80 and compression spring 82 are aligned with the container 72 in the second channel 70 of the SSD slide housing 14 , with the second channel being offset from the first channel 42 and in communication with the first channel via the adjoining channel 68 .
- the compression spring 82 is an energizing source mounted in a compressed state inside the second channel 70 between the interior wall 100 of the SSD slide housing 14 and the enlarged diameter section 98 of the activation pin 80 .
- the SD activation clip 84 keeps the compression spring 82 in its tension state, and thereby keeps the activation pin 80 and the breaking member 78 away from the container 72 .
- the inserted SD activation clip 84 is a spring retainer that prevents activation of the activation mechanism 24 by keeping the fragile container 72 safe from impact by the breaking member 78 .
- removal of the SD activation clip 84 from the decreased diameter portion 86 between the second width side wall 39 of the SSD slide housing 14 and the distal end 88 of the activation pin 80 releases the activation pin for movement within the second channel 70 .
- the timing ball 90 is contained in an aperture of the ball guide 92 and abuts the activation pin 80 .
- the timing ball 90 is free to move laterally within the confines of the guide to allow free movement from the expansional forces applied by the compression spring 82 against the activation pin 80 , which thereby drives the timing ball 90 into the container 72 .
- the fragile container 72 e.g., glass or ceramic ampoule
- the fragile container 72 is breakable upon collision with the breaking member 78 , for example, the timing ball 90 , when the breaking member is pushed into the container by the compression spring 82 .
- the ampoule cup 76 includes an open end 104 for allowing insertion of the container 72 into the cup where it is sealed in place with epoxy sealant within the interior walls of the ampoule cup and its semi-closed end 106 .
- the semi-closed end 106 of the ampoule cup 76 extends radially inward to define the ampoule cup aperture 94 having a diameter slightly less than the pre-deployment diameter of the breaking member 78 , so as to prevent premature passage of the timing ball 90 through the aperture.
- the ampoule cup 76 preferably includes a cylindrical wall extension that holds the ball guide 92 within.
- the timing ball 90 is both a part of the breaking member 78 that breaks the container 72 upon collision, and a weakened area of the activation mechanism 24 that erodes under chemical attack from the reactant fluid 74 and, after a delay, slips through the ampoule cup aperture 94 and allows the compression spring 82 to move the activation pin 80 beyond its prior abutment of the interlock unit 26 . This frees the SD firing pin 48 to overcome the restraint of the interlock unit 26 for release into the SD detonator 40 , as set forth in greater detail below.
- the timing ball 90 is constructed of a material, preferably styrene (e.g., polystyrene) that is both hard enough to break glass or ceramics, and is vulnerable to the reactant fluid 74 (e.g., corrosive agent, acid, solution).
- the timing ball 90 is vulnerable to the reactant fluid, in comparison to the other elements of the activation mechanism discussed above, to fail over time over application of the reactant fluid.
- the reactant fluid 74 erodes the timing ball 90 , changing the structure (e.g., size, shape, hardness, composition) of the ball until it pops through the ampoule cup aperture 94 under the expansive forces of the compression spring 82 .
- timing ball 90 while shown as a sphere, is not limited to that shape. It is more important that the timing ball 90 does not slide through the ampoule cup aperture 94 until after the delay required for the timing ball to erode to a structure that can slide through the aperture sufficiently to allow the interlock unit 26 to release the SD firing pin 48 .
- the stationary self-destruct fuze self destructs or sterilizes the submunition after a preset delay if the submunition fails to explode upon its impact with the ground or a target all while remaining stationary within the slide housing 14 .
- the SSD slide housing 16 which houses the delay mechanism 22 , activation mechanism 24 and interlock unit 26 , remains within the fuze housing 30 preferably by slide holding members 28 . These members hold the SSD slide housing 14 in a locked position within the fuze housing for reliable, desirable self destruction while permitting the movable fuze slide 16 , which holds the primary detonator 18 to shift out after deployment into its armed position.
- FIG. 8 depicts the fuze mechanism 12 with the stationary self-destruct fuze 10 in side view.
- the fuze mechanism 12 is mountable on a submunition 108 and includes a slide lock 110 and a stabilizer ribbon as well understood by a skilled artisan.
- the slide lock 110 is preferably a thin plastic ribbon retainer that holds the stabilizer ribbon and the movable fuze slide 16 in place prior to deployment of the submunition 108 .
- the slide lock 110 prevents premature unfurling of the stabilizer ribbon 110 , and also serves as a secondary safety device to prevents premature movement of the movable fuze slide 16 from its safe position ( FIGS. 1-3 ) to its armed position ( FIGS. 9 , 10 and 12 - 14 ) where the primary detonator 18 is aligned with the main striker of arming screw 18 .
- the slide lock 110 also extracts the SD activation clip 84 and the firing pin safety clip 56 .
- both the firing pin safety clip 56 and the SD activation clip 84 must be extracted before the self-destruct firing pin 48 can release, but neither clip prevents the movable fuze slide 16 from extending to its armed position. That is, slide arming and self-destruct initiation are two separate and independent functions.
- FIGS. 3 and 4 depict an exemplary stationary self-destruct fuze 10 mechanism 12 in perspective and exploded view, respectively.
- the fuze housing 30 is attached to a cover 112 and combined to substantially enclose the delay mechanism 22 , the activation mechanism 24 and the interlock unit 26 .
- the movable fuze slide 16 prior to loading a submunition with its fuze mechanism 12 into a carrier, the movable fuze slide 16 is locked to both the SSD slide housing 14 and the fuze housing 30 via a safety pin 114 .
- a safety clip 116 locks the arming screw 20 in the safe position with a distal tip 118 of the arming screw 20 engaged in the movable fuze slide ( FIG.
- the slide holding members 28 ( FIG. 1 ) lock about the first and second width side walls 37 , 39 on opposite sides of the SSD slide housing 14 to restrict the SSD slide housing movement at least until explosion of the submunition.
- the safety pin 114 and safety clip 116 are both removed preferably immediately prior to placing the submunition into the carrier.
- both the firing pin safety clip 56 and the SD activation clip 84 must be extracted and the activation mechanism 24 must time out (e.g., the activation pin 80 pushing the eroded breaking member 78 into the container 72 and releasing the interlock unit 26 ) before the SD firing pin 48 can move to strike the SD detonator 40 .
- the firing pin safety clip 56 and SD activation clip 84 remain attached to the fuze mechanism 12 until deployment.
- the cover 112 includes a finger bent upright as a backing to retain a fuze slide compression spring 120 against the movable fuze slide 16 .
- the compression spring 120 urges the fuze slide 16 from the safety position to the armed position after deployment.
- an anti-backlash ball 122 slides down into the movable fuze slide 16 when the fuze slide shifts into its armed position as would be readily understood by a skilled artisan.
- FIGS. 5 and 6 depict an exemplary stationary self-destruct (SSD) slide housing 14 in accordance with the preferred embodiments.
- the SSD slide housing 14 is preferably made of a tough, moldable material and is held stationary in the fuze mechanism by the slide holding members 28 of the fuze housing 30 .
- the SSD slide housing has a first channel 42 for housing the delay mechanism 22 , and further includes the second channel 70 for housing the activation mechanism 24 .
- the top bore 126 of the SSD slide housing is preferably aligned with the longitudinal axis of the submunition as a passage for the arming screw 20 to extend through the SSD slide housing as can best be seen in FIGS. 1 and 9 .
- the SSD slide housing further includes a safety pin channel 128 for holding the safety pin 114 until removal of the pin before the submunition is placed into its carrier pre-deployment.
- the SSD slide housing 14 also includes a bi-level movable fuze slide channel 130 defining interior walls 146 that extends to the bottom 132 of the SSD slide housing.
- the bi-level movable fuze slide channel extends from the first width side wall 37 to the second width side wall 39 at the opposite side of the SSD slide housing 14 , and is shaped to house the movable fuze slide 16 in sliding engagement therewith.
- the slide channel 130 also defines shoulders 148 of the interior walls 146 for stopping the movable fuze slide 16 in the armed position and preventing shifting of the movable fuze slide further out of the SSD slide housing beyond the armed position.
- the SSD slide housing 14 also includes a ball channel 144 as further described in greater detail below.
- FIG. 7 depicts an exemplary movable fuze slide 16 slidingly engaged with the SSD slide housing 14 and shaped slightly smaller than and approximate to the bi-level movable fuze slide channel 130 to slide from a safety position within the housing ( FIGS. 1 and 2 ) to an armed position offset from the safety position that aligns the primary detonator 18 with the arming screw 20 ( FIGS. 9 , 10 , 12 and 13 ).
- the movable fuze slide 16 has a two tier top surface 150 shaped to slide within the bi-level movable fuze slide channel 130 .
- the movable fuze slide 16 has a broad lower section 152 and a narrow top section 154 , with the broad lower section split by a gap 156 .
- the narrow top section includes a top side 138 , a first wall 158 and a second wall 160 defining a top section shoulder 162 for abutting one of the shoulders 148 and thus stopping the movable fuze slide 16 from shifting beyond the armed position.
- the movable fuze slide 16 further includes a primary detonator port 134 for holding the primary detonator 18 , and a safety pin port 136 for locking the movable fuze slide 16 with the SSD slide housing 14 via the safety pin 114 when the pin is engaged into the safety pin port.
- the movable fuze slide 16 includes two further ports.
- One of the ports is an arming screw port 140 that extends into the movable fuze slide through the top side 138 of the slide.
- the arming screw port 140 accepts the distal top 118 of the arming screw before deployment as can best be seen in FIG. 1 .
- Another opening extending into the top side 138 of the movable fuze slide 16 defines an anti-backlash ball port 142 that helps to lock the movable fuze slide 16 in its armed position as discussed by example in greater detail below.
- the anti-backlash ball 122 ( FIGS. 2 , 4 , 10 ) is a locking member preferably made of metal (e.g., chrome steel) that holds the movable fuze slide 16 against the SSD slide housing 14 when the movable fuze slide shifts into its armed position.
- metal e.g., chrome steel
- the anti-backlash ball 122 rests in the ball channel 144 ( FIG. 6 ) of the SSD slide housing 14 which is sized having a diameter slightly larger than a diameter of the anti-backlash ball 122 .
- the anti-backlash ball 122 sits within the ball channel 144 where it rests upon the top side 138 ( FIG. 7 ) of the movable fuze slide 16 .
- the anti-backlash ball sits upon the top side of the movable fuze slide, the ball does not impede movement of the movable fuze slide between its safety position and armed position. During this time, that is before the movable fuze slide is shifted to its armed position, the anti-backlash ball 122 is kept within the ball channel 144 as it is blocked from exit of the ball channel by the top side of the movable fuze slide.
- the ball channel 144 of the SSD slide housing is shifted over the anti-backlash ball port 142 of the movable fuze slide 16 .
- This alignment of the ball channel and anti-backlash ball port allows the anti-backlash ball 122 to fall into the anti-backlash ball port 142 ( FIG. 10 ).
- the depth of the anti-backlash ball port 142 is less than the diameter of the anti-backlash ball, and thus the ball does not fall completely out of the ball channel 144 of the SSD slide housing.
- the anti-backlash ball 122 remains housed within both the ball channel 144 and the anti-backlash ball port 142 , where it holds the movable fuze slide 16 in its armed position and thereby prevents further sliding or backlash of the movable fuze slide out of or into the SSD slide housing 14 . Accordingly, once the movable fuze slide 16 shifts into its armed position, the anti-backlash ball 122 holds the movable fuze slide in its position until detonation or sterilization of the SSD fuze 10 .
- FIG. 15 is a flow diagram depicting an exemplary functional sequence of events for explosion of the SSD fuze mechanism 12 of the preferred embodiments.
- an exemplary submunition 108 having the SSD fuze mechanism is expelled from its carrier and encounters the airstream at deployment (Step 200 )
- the force of the airstream discards the slide lock 110 , which removes the firing pin safety clip 56 and the SD activation clip 84 and allows the stabilizer ribbon to unfurl and stabilize the flight of the submunition (Step 202 ).
- the extraction of the SD activation clip 84 frees the activation pin compression spring 82 .
- the compression spring 82 drives the breaking member 78 through both the ball guide 92 , the ampoule cup aperture 94 , and then into the container 72 via the activation pin 80 .
- the breaking member 78 breaks the fragile container 72 and unleashes the reactant fluid 74 through the ampoule cup aperture 94 to the timing ball 90 at Step 204 .
- This exposure of the reactant fluid 74 about the breaking member 78 causes an erosion of the timing ball 90 at step 206 ( FIG. 9 ).
- the extraction of the firing pin safety clip 56 moves the self-destruct firing pin 48 into contact with the interlock ball 64 of the interlock unit 26 .
- the firing pin compression spring 46 is free to expand slightly and shift the self-destruct firing pin incrementally toward the self-destruct detonator 40 .
- the self-destruct firing pin remains urged against the interlock unit 26 by the firing pin compression spring.
- the fuze mechanism 12 appears, for example, at FIG. 10 with the activation pin compression spring 82 partially extended, the container 72 broken at its bottom by the timing ball 90 , the reactant fluid 74 initiating its erosion of the timing ball, and the self-destruct firing pin 48 being urged by the firing pin compression spring 46 against the interlock unit 26 , and more particularly, the SD firing pin releasing interlock ball 64 .
- the size (e.g., diameter) of the polystyrene timing ball 90 forbids its passing through the ampoule cup aperture 94 into the container 72 .
- 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 to resist the rotational spinning of the submunition 108 . This resistance to rotation is transferred to the arming screw 20 , causing the arming screw to rotate against the spinning submunition and back out from its pre-deployment position ( FIG. 1 ) that locks the movable fuze slide 16 in its safe position.
- the backing out of the arming screw 20 from its pre-deployment safe position releases the movable fuze slide 16 to shift, under the rotational forces of the deployed submunition 108 , to its armed position, as readily understood by a skilled artisan.
- the arming screw 20 is always engaged with the SSD slide housing 14 , providing a positive alignment of the arming screw distal tip 118 to the primary detonator 18 when the movable fuze slide 16 is in the armed position.
- submunitions are designed so that when the munition is designed to explode (e.g., upon impact with its target), the arming screw 20 with weight inertia initiates the primary detonator 18 , causing a chain of explosions through the lead charge 21 and main charge 23 ( FIG. 8 ) that destroys the submunition 108 .
- the sequence of events described in this example from the arming screw 20 releasing the movable fuze slide 16 to the destruction of the submunition 108 , occurs during the reaction between the timing ball 90 and the reactant fluid 74 .
- the reactant fluid 74 continues to erode the timing ball 338 ( FIGS. 9 , 10 ).
- a predetermined delay e.g., between about 25 seconds and 5 minutes, the timing ball 90 exposed to the reactant fluid 74 erodes to a point where it is small enough to pop through the ampoule cup aperture 94 .
- the predetermined time period typically varies in accordance with several factors, for example, the composition of the reactant fluid, the composition and density of the timing ball and the ambient temperature, as would be readily understood by a skilled artisan.
- the force of the activation pin compression spring 82 pulses the timing ball through the aperture at Step 208 .
- the compression spring 82 urges the activation pin's proximal section 99 through the ball guide 92 until the enlarged diameter section 98 of the activation pin 80 abuts the ball guide. This movement of the activation pin pushes the timing ball 90 into the container 72 .
- the enlarged diameter section 98 of the activation pin which previously supported the interlock unit 26 , moves out of its supporting position, thereby releasing the interlock balls 64 , 66 to move further through the adjoining channel 68 toward the second channel 70 .
- the self-destruct firing pin 48 pushes the interlock balls, forcing the interlock ball 66 into the second channel 70 .
- the interlock ball 64 is no longer available to restrict movement of the self-destruct firing pin 48 .
- the firing pin compression spring 46 drives the released self-destruct (SD) firing pin 48 toward the self-destruct detonator 22 , causing the SD firing pin to impact and explode the SD detonator 40 .
- FIG. 13 depicts the SD firing pin 48 at impact with the SD detonator 40 .
- output from the exploded SD detonator 40 initiates the adjacent primary detonator 18 , causing it to explode.
- the initiation of the primary detonator 18 from the SD detonator 40 fires the main charge and destroys the submunition 108 (e.g., grenade, missile, rocket warhead munition).
- the submunition 108 e.g., grenade, missile, rocket warhead munition
- the output from the exploded SD detonator 40 initiates and explodes the primary detonator 18 , which at least sterilizes the submunition 108 .
- the chain of explosions at step 214 may still initiate the submunition's main charge if the output from the SD detonator 40 and/or the primary detonator 18 are sufficient to initiate the non-aligned main charge. Accordingly, the stationary self-destruct fuze 10 ensures sterilization or destruction of the submunition 108 in a timely manner in accordance with the relationship between the primary detonator 18 and the main charge.
- the SD fuze delay device is applicable to all the various ICM items including the submunitions of the non-rotating GMLRS/MLRS warheads.
- 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.
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Abstract
A fuze mechanism for a submuntion includes an activation mechanism having a container filled with an activation fluid and an ampoule breaker to break the container upon deployment of the munition, a delay mechanism including a spring-loaded self-destruct firing pin to initiate a secondary detonator in close proximity to a primary detonator, and an interlock unit supported by the ampoule breaker that locks the self-destruct firing pin away from the secondary detonator. The ampoule breaker includes a piston and a timing ball, which accesses the activation liquid. The action of the activation liquid on the timing ball over time causes the timing ball to erode until it is forced into the container by the spring-loaded piston. The movement of the piston frees the interlock unit, allowing the spring-loaded self-destruct firing pin to move under force and impact or initiate the secondary detonator. Initiation of the secondary detonator destroys the primary detonator and, depending upon slide location, either sterilizes or destroys the submunition. The activation mechanism, delay mechanism and interlock unit are housed in a stationary self destruct slide housing for safe and reliable use of the fuze mechanism.
Description
- 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 subminitions would not function for various reasons. This failure rate of about 5% presents both an environmental and a humanitarian hazard. Unexploded Ordnance (UXO) 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.
- U.S. Pat. No. 7,530,313 to Chamlee, et al., discloses a submunition having a slide that houses a self-destruct fuze delay. The delay includes a container filled with an activation fluid, a spring-loaded ampoule breaker to break the container upon deployment of the munition, a spring-loaded self-destruct firing pin to initiate a secondary detonator in close proximity to a primary detonator, and an interlock ball supported by the ampoule breaker that locks the self-destruct firing pin away from the secondary detonator. The ampoule breaker includes a piston and a timing ball, which accesses the activation liquid. The action of the activation liquid on the timing ball over time causes the timing ball to erode until it is forced into the container by the spring-loaded piston. The movement of the piston frees the interlock ball, allowing the spring-loaded self-destruct firing pin to move under force and impact or initiate the secondary detonator. Initiation of the secondary detonator destroys the primary detonator and, depending upon slide location, either sterilizes the submunition, or destroys the entire submunition.
- The current self-destruct fuze development still does not consistently meet the overriding human safety requirement to reduce unexploded hazardous duds and unexploded ordinances to at least one percent. Accordingly, it would still be beneficial to provide more reliable 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.
- The preferred embodiments include a self-destruct detonating fuze for a submunition having a longitudinal axis, a main charge and the self-destruct detonating fuze for initiating the main charge upon impact. The exemplary self-destruct detonating fuze includes a self-destruct slide housing holding a first detonator, a movable fuze slide slidingly engaged with the self-destruct slide housing between a safe position and an armed position with the movable fuze slide having a second detonator mounted thereto, and a slide housing holding member permanently engaged with the self-destruct slide housing and holding the self-destruct slide housing in a stationary position relative to the submunition regardless of the position of the movable fuze slide. This stationary self-destruct slide housing includes a delay mechanism, an interlock unit and an activation mechanism. The delay mechanism is offset and substantially orthogonal to the longitudinal axis of the submunition. The delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the first detonator and urged toward the first detonator in a first direction by the energizing source to explode the first detonator. The interlock unit is movable between a first position within the self-destruct slide housing, in which the interlock unit abuts the self-destruct firing pin and restrains the self-destruct firing pin away from the first detonator, and a second position within the self-destruct slide housing offset from the first position in a second direction in which the interlock unit allows the energizing source to move the self-destruct firing pin into the first detonator. The activation mechanism is offset from the delay mechanism and supports the interlock unit in the first position against the self-destruct firing pin. The activation mechanism is adapted to shift after a delay and release its support of the interlock unit against the self-destruct firing pin to allow movement of the interlock unit to the second position.
- The preferred embodiments also include a self-destruct detonating fuze for a submunition having a longitudinal axis, a main charge and the self-destruct detonating fuze for initiating the main charge upon impact. The self-destruct detonating fuze includes a self-destruct slide housing holding a first detonator, a movable fuze slide slidingly engaged with the self-destruct slide housing between a safe position and an armed position with the movable fuze slide having a second detonator mounted thereto, and a slide housing holding member permanently engaged with the self-destruct slide housing and holding the self-destruct slide housing in a stationary position relative to the submunition regardless of the position of the movable fuze slide. This stationary self-destruct slide housing also includes a delay mechanism, an interlock unit and an activation mechanism. The delay mechanism is offset and substantially orthogonal to the longitudinal axis. The delay mechanism includes an energizing source and a self-destruct firing pin, with the self-destruct firing pin aligned with the first detonator and urged into the first detonator by the energizing source. The activation mechanism is offset from the delay mechanism, and 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-destruct firing pin. The interlock 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 first 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 first detonator. Preferably, the self-destruct slide housing includes a channel between the delay mechanism and the activation mechanism, and the interlock unit includes at least one interlock ball that moves within the channel between the first position and the second position.
- While not being limited to a particular theory, the preferred slide housing holding member includes a fuze housing. The fuze housing is fixedly secured to the submunition and covers the stationary self-destruct slide housing. The fuze housing includes a slide housing locking unit extending around and holding the self-destruct slide housing in the stationary position relative to the submunition. It should also be noted that the slide housing holding member preferably further includes an arming screw received within an aperture of the stationary self-destruct slide housing. The aperture is aligned between the arming screw and the second detonator when the movable fuze slide is in the armed position. While not considered a primary function of the arming screw, it is contemplated that the arming screw may also retain the self-destruct slide housing in the stationary position relative to the submunition.
- The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein:
-
FIG. 1 is a top sectional view of an exemplary stationary self-destruct fuze mechanism according to the preferred embodiments; -
FIG. 2 depicts the fuze mechanism shown inFIG. 1 from a side sectional view; -
FIG. 3 is a perspective view of the exemplary stationary self-destruct fuze mechanism prior to loading into a carrier; -
FIG. 4 is an exploded view of the exemplary stationary self-destruct fuze mechanism; -
FIG. 5 is a perspective view of the stationary self-destruct slide housing; -
FIG. 6 is a perspective view of the stationary self-destruct slide housing underside; -
FIG. 7 is a perspective view of the movable fuze slide; -
FIG. 8 is a side view of the exemplary stationary self-destruct fuze mechanism and partial side view of the attached charge before deployment into the atmosphere; -
FIG. 9 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism shown inFIG. 1 after deployment; -
FIG. 10 is a side view partially in section of the exemplary fuze delay device shown inFIG. 9 ; -
FIG. 11 is a side view of the timing ball and ampoule cup shown inFIGS. 9 and 10 ; -
FIG. 12 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism ofFIG. 1 after erosion of the timing ball; -
FIG. 13 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism ofFIG. 1 after release of the restraining unit and fuze slide in an armed position; -
FIG. 14 is a top view partially in section of the exemplary stationary self-destruct fuze mechanism ofFIG. 1 after release of the restraining unit and fuze slide not in the armed position; and -
FIG. 15 is a flow diagram depicting an exemplary sequence of events for the destruction of the fuze mechanism. - Exemplary embodiments for a stationary self-destruct (SSD) fuze mechanism are described with reference to the figures noted above. Although the preferred SSD fuze is applicable to all the various ICM items, in the interest of brevity, the exemplary SSD fuze mechanisms are generally tailored toward use in the M864, M155 MM projectile which contains 72 submunitions, each with its own SSD fuze. While not being limited to a particular theory, the submunitions typically are disbursed via an expulsion charge that explodes in flight creating ample internal pressure to shear the base plate threads and expel the cargo out the rear of the projectile and 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 SSD fuze mechanisms of the preferred embodiments incorporate a predetermined time delay (e.g., about 25 seconds minimum to about 5 minutes) that is greater than the foreseeable flight time of the respective 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 SSD fuze mechanisms destroy the submunition or sterilize the fuze if the submunition fails to explode after it strikes the ground or target. The fuze also retains the positive operation of the M223/M239 fuze, that is, it utilizes the stabilizer ribbon, arming screw and slide to retain the known out-of-line safety features.
- 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,
FIGS. 1-15 depict an exemplary stationary self-destruct (SSD) fuze 10 as part of aSSD fuze mechanism 12 for a submunition, as readily understood by a skilled artisan. TheSSD fuze 10 includes a stationary self-destruct slide housing 14 slidingly engaged with amovable fuze slide 16 of thefuze mechanism 12. Themovable fuze slide 16 holds aprimary detonator 18 that shifts with the slide between a safety position (FIGS. 1 , 3), where the primary detonator is not aligned with a main striker (e.g. arming screw 20), and an armed position (FIGS. 9 , 10), where the primary detonator is aligned with the arming screw preferably along the longitudinal axis of the submunition between the arming screw and the submunition. - As can be seen in
FIGS. 1 and 4 , theslide holding members 28 in this exemplary embodiment extend from afuze housing 30 as metal fingers bending down and about theSSD slide housing 14. The fuze housing is preferably made of metal and maintains the slide housing in its stationary position relative to the submunition regardless of the position of themovable fuze slide 16. For example, thefuze housing 30 includes afirst side wall 32 and opposingsecond side wall 34 that abut and hold a firstlengthwise wall 36 and secondlengthwise wall 38 of theSSD slide housing 14, while theslide holding members 28 abut and hold a firstwidth side wall 37 and opposing secondwidth side wall 39, of the SSD slide housing. Thus theside walls members 28 combine to rigidly secure and protect theSSD slide housing 14 stationary relative to the submunition. This is especially beneficial to protect the internal components (e.g.,movable fuze slide 16,detonators screw 20,delay mechanism 22,activation mechanism 24, interlock unit 26) from damage from severe premature impacts. - The
delay mechanism 22 of theSSD fuze 10 includes a self-destruct (SD)detonator 40 that is arranged in afirst channel 42 of theSSD slide housing 14 offset and substantially orthogonal to the longitudinal axis of the submunition and to the armingscrew 20. A self-destruct detonator retainer 44 preferable formed of a plastic or metal secured (e.g., by adhesives, crimping, friction, heat) to an inner-cylindrical wall 46 of thechannel 42 to seal the self-destruct detonator 40 within the channel. Thedelay mechanism 22 also includes acompression spring 46 as an energizing source, and a self-destruct (SD)firing pin 48, both preferably formed of metal or other hard material and located within thefirst channel 42. - The
SD firing pin 48 includes afront end 50 proximate the self-destruct detonator 40 and a spring holdingrod section 52. While not being limited to a particular theory, therod section 52 prior to deployment extends through a reduceddiameter 54 of thefirst channel 42 at the secondwidth side wall 39 of theSSD slide housing 14, where it is held in place by a firingpin safety clip 56, as would readily be understood by a skilled artisan. In this arrangement shown inFIG. 2 , thefiring pin clip 56 holds the firingpin compression spring 46 in a state of tension between thefront end 50 of the firing pin and aninterior shoulder wall 58 of thefirst channel 42. The firingpin safety clip 56 slides about a narrowedportion 60 of therod section 52 between adistal end 62 of the SD firing pin 48 (FIG. 10 ) and the second withside wall 39 of theSSD slide housing 14. As can be seen inFIG. 2 , theSD firing pin 48 is aligned with theSD detonator 40 and movable along thefirst channel 42 to explode the detonator upon release of the SD firing pin and thecompression spring 46 as described by example in greater detail below. - The
interlock unit 26 is shown inFIG. 2 as including as part of a restraining unit that secures theSD firing pin 48 during a predetermined delay away from theSD detonator 40. While not being limited to a particular theory, theinterlock unit 26 includes at least one, and preferable twointerlock balls channel 68 of theSSD slide housing 14 between thefirst channel 42 of the slide housing and asecond channel 70 of the slide housing. It should be noted that while the adjoiningchannels 68 is shown substantially orthogonal to the generally parallel directions of the first andsecond channels preferred interlock unit 26 includes twointerlock balls channel 68 and that extend from theactivation mechanism 24 to restrict movement of thefiring pin 48 for a predetermined self-destruct time after deployment of the submunition. - The
activation mechanism 24 is offset from thedelay mechanism 22 and supports theinterlock unit 26 in a position that restricts movement of theSD firing pin 48 toward theSD detonator 40. As will be described in greater detail below, the activation mechanism is adapted to shift after a time delay and release its support of the interlock unit against the self-destruct firing pin to allow movement of the interlock unit to a position that frees the firing pin to explode the SD detonator. - While not being limited to a particular theory, the
activation mechanism 24 is located in thesecond channel 70, which is offset from thefirst channel 42 that houses thedelay mechanism 22. Theactivation mechanism 24 includes a breakable container 72 (e.g., glass ampoule, ceramic ampoule) that holds areactant fluid 74. Thereactant fluid 74 is preferable a corrosive agent (e.g., acid or liquid solution) that chemically attacks and causes certain materials (e.g. hard plastics) of theinterlock unit 26 to erode over time. Thecontainer 72 is partially housed in a generally cup-shapedampoule cup 76 that is a resilient insulator preferably not susceptible to thereactant fluid 74 so that the reactant fluid does not erode the ampoule cup if it inadvertently leaks out of the container. The resilientinsulative ampoule cup 76 seals thecontainer 72 and other elements of theactivation mechanism 24 discussed below within thesecond channel 70 of theSSD slide housing 14. In particular, thecontainer 72 is sealed inside theampoule cup 76 preferably with an epoxy, and then secured inside thesecond channel 70 as a unit. Theampoule cup 76 also contains the orifice (e.g., ampoule cup aperture 94) through which thetiming ball 90 must pass to release the self-destruct firing pin 48, as discussed in greater detail below. - Still referring to
FIG. 2 , theactivation mechanism 24 further includes a breaking member (e.g., timing ball) 78, anactivation pin 80, and an activationpin compression spring 82, which is shown inFIG. 2 as being held in a compressed state by a self-destruct (SD)activation clip 84. That is, theSD activation clip 84 slides about a decreaseddiameter portion 86 of theactivation pin 80 between adistal end 88 of the activation pin and the outer force of thesecond width sidewall 39 of theSSD slide housing 14. - The breaking
member 78 is an ampoule breaker that upon release of theSD activation clip 84 is urged by thecompression spring 82 into impact with thecontainer 72, causing the container to break and release thereactant fluid 74 into communication with the breaking member. Preferably, the breaking member is atiming ball 90 made of a hard plastic or similar material that is hard enough to break glass or similar fragile material (e.g., ceramic), and that erodes when exposed to thereactant fluid 74. While not being limited to a particular theory, aresilient sleeve 92 centers thetiming ball 90 in thesecond channel 70 and keeps the timing ball aligned between the glass ampoule and theactivation pin 80. - The
ampoule cup 76 preferably includes a semi-closed end with anaperture 94 facing thetiming ball 90. Theaperture 94 in the ampoule cup is large enough to allow direct contact between the timingball 90 and the container 72 (e.g. glass ampoule), but is small enough to still prevent the ball from passing through until the reactant fluid has reduced the diameter. As can best be see inFIG. 11 , the exemplaryampoule cup aperture 94 is not completely circular, but is shaped to includeaperture grooves 96 for allowing thereactant fluid 74 access to the side and back ends of thetiming ball 90. That is, theaperture grooves 96 allow the reactant fluid to seep to the outer surfaces of the timing ball for greater coverage of the ball beyond theaperture 94. Without theaperture grooves 96, thetiming ball 90 would emulate a plug and prevent thereactant fluid 74 from coating and dissolving the surface of the timing ball. Accordingly, theaperture 94 and breakingmember 78 preferably have different shapes at their intersection to allow fluid bypass through their meeting. It is understood that theaperture 94 is not limited by shape or size by the aperture shown inFIG. 11 . Theampoule cup aperture 94, or its equivalents, such as a metal member placed between thecontainer 22 andtiming ball 90, provide a means for permitting fluid communication between the timing ball and thereactant fluid 74. - While not being limited to a particular theory, the
activation pin 80 is a generally rod-shaped metal unit that holds the breakingmember 78 against the ball guide 92 before deployment. In particular, theactivation pin 80 includes anenlarged diameter section 98 that abuts thecompression spring 82, and aproximal section 99 between theenlarged diameter section 98 and thetiming ball 90. During deployment and after release of theSD activation clip 84, theactivation pin 80 is urged by thecompression spring 82 toward thefragile container 72, pushing the breakingmember 78 at least partially past theampoule cup aperture 94 at the semi-closed end of theampoule cup 76 into thecontainer 72, breaking the container and releasing thereactant fluid 74 onto the breakingmember 78. Before deployment, theSD activation clip 84 holds thecompression spring 82 in a state of tension between theenlarged diameter section 98 of theactivation pin 80 and aninterior wall 100 of theSSD slide housing 14. Before and during deployment, theenlarged diameter section 98 also abuts and supports theinterlock unit 26 to its first position where the interlock unit prevents the self-destruct firing pin 48 from moving into and exploding the self-destruct detonator 40. - As noted above, the breaking
member 78,activation pin 80 andcompression spring 82 are aligned with thecontainer 72 in thesecond channel 70 of theSSD slide housing 14, with the second channel being offset from thefirst channel 42 and in communication with the first channel via the adjoiningchannel 68. Thecompression spring 82 is an energizing source mounted in a compressed state inside thesecond channel 70 between theinterior wall 100 of theSSD slide housing 14 and theenlarged diameter section 98 of theactivation pin 80. When inserted against theSSD slide housing 14, as shown inFIGS. 1 and 2 , theSD activation clip 84 keeps thecompression spring 82 in its tension state, and thereby keeps theactivation pin 80 and the breakingmember 78 away from thecontainer 72. Therefore, the insertedSD activation clip 84 is a spring retainer that prevents activation of theactivation mechanism 24 by keeping thefragile container 72 safe from impact by the breakingmember 78. As will be discussed in greater detail below, removal of theSD activation clip 84 from the decreaseddiameter portion 86 between the secondwidth side wall 39 of theSSD slide housing 14 and thedistal end 88 of theactivation pin 80 releases the activation pin for movement within thesecond channel 70. - Still referring to
FIGS. 1 and 2 , thetiming ball 90 is contained in an aperture of theball guide 92 and abuts theactivation pin 80. Preferably, thetiming ball 90 is free to move laterally within the confines of the guide to allow free movement from the expansional forces applied by thecompression spring 82 against theactivation pin 80, which thereby drives thetiming ball 90 into thecontainer 72. The fragile container 72 (e.g., glass or ceramic ampoule) is breakable upon collision with the breakingmember 78, for example, thetiming ball 90, when the breaking member is pushed into the container by thecompression spring 82. - While not being limited to a particular theory, the
ampoule cup 76 includes anopen end 104 for allowing insertion of thecontainer 72 into the cup where it is sealed in place with epoxy sealant within the interior walls of the ampoule cup and itssemi-closed end 106. Thesemi-closed end 106 of theampoule cup 76 extends radially inward to define theampoule cup aperture 94 having a diameter slightly less than the pre-deployment diameter of the breakingmember 78, so as to prevent premature passage of thetiming ball 90 through the aperture. As can be seen inFIGS. 1 and 2 , theampoule cup 76 preferably includes a cylindrical wall extension that holds the ball guide 92 within. - The
timing ball 90 is both a part of the breakingmember 78 that breaks thecontainer 72 upon collision, and a weakened area of theactivation mechanism 24 that erodes under chemical attack from thereactant fluid 74 and, after a delay, slips through theampoule cup aperture 94 and allows thecompression spring 82 to move theactivation pin 80 beyond its prior abutment of theinterlock unit 26. This frees theSD firing pin 48 to overcome the restraint of theinterlock unit 26 for release into theSD detonator 40, as set forth in greater detail below. As such, thetiming ball 90 is constructed of a material, preferably styrene (e.g., polystyrene) that is both hard enough to break glass or ceramics, and is vulnerable to the reactant fluid 74 (e.g., corrosive agent, acid, solution). In particular, thetiming ball 90 is vulnerable to the reactant fluid, in comparison to the other elements of the activation mechanism discussed above, to fail over time over application of the reactant fluid. As can be seen inFIGS. 9 , 10 and 12, thereactant fluid 74 erodes thetiming ball 90, changing the structure (e.g., size, shape, hardness, composition) of the ball until it pops through theampoule cup aperture 94 under the expansive forces of thecompression spring 82. It is understood that thetiming ball 90, while shown as a sphere, is not limited to that shape. It is more important that thetiming ball 90 does not slide through theampoule cup aperture 94 until after the delay required for the timing ball to erode to a structure that can slide through the aperture sufficiently to allow theinterlock unit 26 to release theSD firing pin 48. - The stationary self-destruct fuze self destructs or sterilizes the submunition after a preset delay if the submunition fails to explode upon its impact with the ground or a target all while remaining stationary within the
slide housing 14. As discussed above, theSSD slide housing 16, which houses thedelay mechanism 22,activation mechanism 24 andinterlock unit 26, remains within thefuze housing 30 preferably byslide holding members 28. These members hold theSSD slide housing 14 in a locked position within the fuze housing for reliable, desirable self destruction while permitting themovable fuze slide 16, which holds theprimary detonator 18 to shift out after deployment into its armed position. As noted above, the self-destruct fuze 10 self destructs the attached submunition after a preset delay if the submunition fails to explode upon its impact with the ground or a target.FIG. 8 depicts thefuze mechanism 12 with the stationary self-destruct fuze 10 in side view. As can be seen inFIG. 8 , thefuze mechanism 12 is mountable on asubmunition 108 and includes aslide lock 110 and a stabilizer ribbon as well understood by a skilled artisan. Theslide lock 110 is preferably a thin plastic ribbon retainer that holds the stabilizer ribbon and themovable fuze slide 16 in place prior to deployment of thesubmunition 108. That is, theslide lock 110 prevents premature unfurling of thestabilizer ribbon 110, and also serves as a secondary safety device to prevents premature movement of themovable fuze slide 16 from its safe position (FIGS. 1-3 ) to its armed position (FIGS. 9 , 10 and 12-14) where theprimary detonator 18 is aligned with the main striker of armingscrew 18. When discarded upon expulsion, theslide lock 110 also extracts theSD activation clip 84 and the firingpin safety clip 56. While not being limited to a particular theory, both the firingpin safety clip 56 and theSD activation clip 84 must be extracted before the self-destruct firing pin 48 can release, but neither clip prevents themovable fuze slide 16 from extending to its armed position. That is, slide arming and self-destruct initiation are two separate and independent functions. -
FIGS. 3 and 4 depict an exemplary stationary self-destruct fuze 10mechanism 12 in perspective and exploded view, respectively. As can be seen inFIGS. 3 and 8 , thefuze housing 30 is attached to acover 112 and combined to substantially enclose thedelay mechanism 22, theactivation mechanism 24 and theinterlock unit 26. Referring now toFIGS. 3 and 4 , prior to loading a submunition with itsfuze mechanism 12 into a carrier, themovable fuze slide 16 is locked to both theSSD slide housing 14 and thefuze housing 30 via asafety pin 114. Asafety clip 116 locks the armingscrew 20 in the safe position with adistal tip 118 of the armingscrew 20 engaged in the movable fuze slide (FIG. 1 ). As noted above, the slide holding members 28 (FIG. 1 ) lock about the first and secondwidth side walls SSD slide housing 14 to restrict the SSD slide housing movement at least until explosion of the submunition. Thesafety pin 114 andsafety clip 116 are both removed preferably immediately prior to placing the submunition into the carrier. In this preferred embodiment, both the firingpin safety clip 56 and theSD activation clip 84 must be extracted and theactivation mechanism 24 must time out (e.g., theactivation pin 80 pushing the eroded breakingmember 78 into thecontainer 72 and releasing the interlock unit 26) before theSD firing pin 48 can move to strike theSD detonator 40. The firingpin safety clip 56 andSD activation clip 84 remain attached to thefuze mechanism 12 until deployment. - The
cover 112 includes a finger bent upright as a backing to retain a fuzeslide compression spring 120 against themovable fuze slide 16. Thecompression spring 120 urges thefuze slide 16 from the safety position to the armed position after deployment. As can be seen inFIG. 4 , ananti-backlash ball 122 slides down into themovable fuze slide 16 when the fuze slide shifts into its armed position as would be readily understood by a skilled artisan. -
FIGS. 5 and 6 depict an exemplary stationary self-destruct (SSD) slidehousing 14 in accordance with the preferred embodiments. TheSSD slide housing 14 is preferably made of a tough, moldable material and is held stationary in the fuze mechanism by theslide holding members 28 of thefuze housing 30. As can best be seen inFIG. 5 , the SSD slide housing has afirst channel 42 for housing thedelay mechanism 22, and further includes thesecond channel 70 for housing theactivation mechanism 24. Thetop bore 126 of the SSD slide housing is preferably aligned with the longitudinal axis of the submunition as a passage for the armingscrew 20 to extend through the SSD slide housing as can best be seen inFIGS. 1 and 9 . The SSD slide housing further includes asafety pin channel 128 for holding thesafety pin 114 until removal of the pin before the submunition is placed into its carrier pre-deployment. As can best be seen inFIGS. 5 and 6 , theSSD slide housing 14 also includes a bi-level movablefuze slide channel 130 defininginterior walls 146 that extends to thebottom 132 of the SSD slide housing. The bi-level movable fuze slide channel extends from the firstwidth side wall 37 to the secondwidth side wall 39 at the opposite side of theSSD slide housing 14, and is shaped to house themovable fuze slide 16 in sliding engagement therewith. Theslide channel 130 also definesshoulders 148 of theinterior walls 146 for stopping themovable fuze slide 16 in the armed position and preventing shifting of the movable fuze slide further out of the SSD slide housing beyond the armed position. Referring toFIG. 6 , theSSD slide housing 14 also includes aball channel 144 as further described in greater detail below. -
FIG. 7 depicts an exemplarymovable fuze slide 16 slidingly engaged with theSSD slide housing 14 and shaped slightly smaller than and approximate to the bi-level movablefuze slide channel 130 to slide from a safety position within the housing (FIGS. 1 and 2 ) to an armed position offset from the safety position that aligns theprimary detonator 18 with the arming screw 20 (FIGS. 9 , 10, 12 and 13). As can be seen inFIG. 7 , themovable fuze slide 16 has a two tiertop surface 150 shaped to slide within the bi-level movablefuze slide channel 130. In particular, themovable fuze slide 16 has a broadlower section 152 and a narrowtop section 154, with the broad lower section split by agap 156. The narrow top section includes atop side 138, afirst wall 158 and asecond wall 160 defining atop section shoulder 162 for abutting one of theshoulders 148 and thus stopping themovable fuze slide 16 from shifting beyond the armed position. Themovable fuze slide 16 further includes aprimary detonator port 134 for holding theprimary detonator 18, and asafety pin port 136 for locking themovable fuze slide 16 with theSSD slide housing 14 via thesafety pin 114 when the pin is engaged into the safety pin port. - Still referring to
FIG. 7 , themovable fuze slide 16 includes two further ports. One of the ports is an armingscrew port 140 that extends into the movable fuze slide through thetop side 138 of the slide. The armingscrew port 140 accepts thedistal top 118 of the arming screw before deployment as can best be seen inFIG. 1 . Another opening extending into thetop side 138 of themovable fuze slide 16 defines ananti-backlash ball port 142 that helps to lock themovable fuze slide 16 in its armed position as discussed by example in greater detail below. - The anti-backlash ball 122 (
FIGS. 2 , 4, 10) is a locking member preferably made of metal (e.g., chrome steel) that holds themovable fuze slide 16 against theSSD slide housing 14 when the movable fuze slide shifts into its armed position. Before deployment, theanti-backlash ball 122 rests in the ball channel 144 (FIG. 6 ) of theSSD slide housing 14 which is sized having a diameter slightly larger than a diameter of theanti-backlash ball 122. Here, theanti-backlash ball 122 sits within theball channel 144 where it rests upon the top side 138 (FIG. 7 ) of themovable fuze slide 16. While the anti-backlash ball sits upon the top side of the movable fuze slide, the ball does not impede movement of the movable fuze slide between its safety position and armed position. During this time, that is before the movable fuze slide is shifted to its armed position, theanti-backlash ball 122 is kept within theball channel 144 as it is blocked from exit of the ball channel by the top side of the movable fuze slide. - When the
movable fuze slide 16 is shifted to its armed position, such that theprimary detonator 18 is aligned with the armingscrew 20, theball channel 144 of the SSD slide housing is shifted over theanti-backlash ball port 142 of themovable fuze slide 16. This alignment of the ball channel and anti-backlash ball port allows theanti-backlash ball 122 to fall into the anti-backlash ball port 142 (FIG. 10 ). However, the depth of theanti-backlash ball port 142 is less than the diameter of the anti-backlash ball, and thus the ball does not fall completely out of theball channel 144 of the SSD slide housing. Instead, theanti-backlash ball 122 remains housed within both theball channel 144 and theanti-backlash ball port 142, where it holds themovable fuze slide 16 in its armed position and thereby prevents further sliding or backlash of the movable fuze slide out of or into theSSD slide housing 14. Accordingly, once themovable fuze slide 16 shifts into its armed position, theanti-backlash ball 122 holds the movable fuze slide in its position until detonation or sterilization of theSSD fuze 10. -
FIG. 15 is a flow diagram depicting an exemplary functional sequence of events for explosion of theSSD fuze mechanism 12 of the preferred embodiments. When anexemplary submunition 108 having the SSD fuze mechanism is expelled from its carrier and encounters the airstream at deployment (Step 200), the force of the airstream discards theslide lock 110, which removes the firingpin safety clip 56 and theSD activation clip 84 and allows the stabilizer ribbon to unfurl and stabilize the flight of the submunition (Step 202). The extraction of theSD activation clip 84 frees the activationpin compression spring 82. Upon its release, thecompression spring 82 drives the breakingmember 78 through both theball guide 92, theampoule cup aperture 94, and then into thecontainer 72 via theactivation pin 80. The breakingmember 78 breaks thefragile container 72 and unleashes thereactant fluid 74 through theampoule cup aperture 94 to thetiming ball 90 atStep 204. This exposure of thereactant fluid 74 about the breaking member 78 (e.g., timing ball 90) causes an erosion of thetiming ball 90 at step 206 (FIG. 9 ). - As can best be seen in
FIG. 10 , the extraction of the firingpin safety clip 56 moves the self-destruct firing pin 48 into contact with theinterlock ball 64 of theinterlock unit 26. In other words, with the firingpin safety clip 56 no longer available as support for the self-destruct firing pin 48, the firingpin compression spring 46 is free to expand slightly and shift the self-destruct firing pin incrementally toward the self-destruct detonator 40. At this time, the self-destruct firing pin remains urged against theinterlock unit 26 by the firing pin compression spring. - As
steps fuze mechanism 12 appears, for example, atFIG. 10 with the activationpin compression spring 82 partially extended, thecontainer 72 broken at its bottom by thetiming ball 90, thereactant fluid 74 initiating its erosion of the timing ball, and the self-destruct firing pin 48 being urged by the firingpin compression spring 46 against theinterlock unit 26, and more particularly, the SD firing pin releasinginterlock ball 64. As this point, the size (e.g., diameter) of thepolystyrene timing ball 90 forbids its passing through theampoule cup aperture 94 into thecontainer 72. - 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 to resist the rotational spinning of the
submunition 108. This resistance to rotation is transferred to the armingscrew 20, causing the arming screw to rotate against the spinning submunition and back out from its pre-deployment position (FIG. 1 ) that locks themovable fuze slide 16 in its safe position. Preferably the backing out of the armingscrew 20 from its pre-deployment safe position releases themovable fuze slide 16 to shift, under the rotational forces of the deployedsubmunition 108, to its armed position, as readily understood by a skilled artisan. It should be noted that the armingscrew 20 is always engaged with theSSD slide housing 14, providing a positive alignment of the arming screwdistal tip 118 to theprimary detonator 18 when themovable fuze slide 16 is in the armed position. - It is generally recognized that not all submunitions are spinning projectiles. For example, some missile warheads are non-spin; meaning that rotation is not available to arm a deployed submunition. Here, 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 arming
screw 20 with weight inertia initiates theprimary detonator 18, causing a chain of explosions through thelead charge 21 and main charge 23 (FIG. 8 ) that destroys thesubmunition 108. In the preferred embodiments, the sequence of events described in this example, from the armingscrew 20 releasing themovable fuze slide 16 to the destruction of thesubmunition 108, occurs during the reaction between the timingball 90 and thereactant fluid 74. In other words, if thesubmunition 108 works as normally intended, the chain of explosions will destroy the submunition before the release of the selfdestruct firing pin 48 to the self-destruct detonator 40 while thereactant fluid 74 erodes thetiming ball 90 outside thecontainer 72. - However, if the
submunition 108 does not function normally, that is, explode upon hitting its target; thereactant fluid 74 continues to erode the timing ball 338 (FIGS. 9 , 10). After a predetermined delay (e.g., between about 25 seconds and 5 minutes, thetiming ball 90 exposed to thereactant fluid 74 erodes to a point where it is small enough to pop through theampoule cup aperture 94. The predetermined time period typically varies in accordance with several factors, for example, the composition of the reactant fluid, the composition and density of the timing ball and the ambient temperature, as would be readily understood by a skilled artisan. - As the
timing ball 90 erodes to a size small enough to fit through theampoule cup aperture 94, the force of the activationpin compression spring 82 pulses the timing ball through the aperture atStep 208. As can be seen inFIGS. 12-14 , thecompression spring 82 urges the activation pin'sproximal section 99 through the ball guide 92 until theenlarged diameter section 98 of theactivation pin 80 abuts the ball guide. This movement of the activation pin pushes thetiming ball 90 into thecontainer 72. As a result of this movement, theenlarged diameter section 98 of the activation pin, which previously supported theinterlock unit 26, moves out of its supporting position, thereby releasing theinterlock balls channel 68 toward thesecond channel 70. As can be seen inFIG. 12 , the self-destruct firing pin 48 pushes the interlock balls, forcing theinterlock ball 66 into thesecond channel 70. At this time, theinterlock ball 64 is no longer available to restrict movement of the self-destruct firing pin 48. - Accordingly, the movement of the
timing ball 90 into thecontainer 72 instep 208 releases the self-destruct firing pin 48. AtStep 210, the firingpin compression spring 46 drives the released self-destruct (SD)firing pin 48 toward the self-destruct detonator 22, causing the SD firing pin to impact and explode theSD detonator 40. See, for example,FIG. 13 , which depicts theSD firing pin 48 at impact with theSD detonator 40. As can be seen inFIG. 13 , output from the explodedSD detonator 40 initiates the adjacentprimary detonator 18, causing it to explode. If at this time themovable fuze slide 16 is in its armed position, such that theprimary detonator 18 is aligned with the armingscrew 20 and the main charge, then atStep 212 the initiation of theprimary detonator 18 from theSD detonator 40 fires the main charge and destroys the submunition 108 (e.g., grenade, missile, rocket warhead munition). - However, if the
movable fuze slide 16 is not in the armed position (e.g., the movable fuze slide did not complete its shift to arm and instead remains in the safe position or in a position between its safe an armed position where theprimary detonator 18 is not aligned with the main charge as show by example inFIG. 14 ), then at step 214 the output from the explodedSD detonator 40 initiates and explodes theprimary detonator 18, which at least sterilizes thesubmunition 108. As can be appreciated by a skilled artisan, the chain of explosions at step 214 may still initiate the submunition's main charge if the output from theSD detonator 40 and/or theprimary detonator 18 are sufficient to initiate the non-aligned main charge. Accordingly, the stationary self-destruct fuze 10 ensures sterilization or destruction of thesubmunition 108 in a timely manner in accordance with the relationship between theprimary detonator 18 and the main charge. - 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. 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.
Claims (20)
1. A self-destruct detonating fuze for a submunition, said submunition having a longitudinal axis, a main charge and said self-destruct detonating fuze for initiating the main charge upon impact, said self-destruct detonating fuze comprising:
a self-destruct slide housing holding a first detonator;
a movable fuze slide slidingly engaged with said self-destruct slide housing between a safe position and an armed position, said movable fuze slide having a second detonator mounted thereto;
a slide housing holding member permanently engaged with said self-destruct slide housing and holding said self-destruct slide housing in a stationary position relative to the submunition regardless of the position of said movable fuze slide;
said stationary self-destruct slide housing including
a delay mechanism offset and substantially orthogonal to the longitudinal axis of the submunition, said delay mechanism including an energizing source and a self-destruct firing pin, said self-destruct firing pin aligned with said first detonator and urged toward said first detonator in a first direction by said energizing source to explode said first detonator,
an interlock unit movable between a first position within said self-destruct slide housing, in which said interlock unit abuts said self-destruct firing pin and restrains said self-destruct firing pin away from said first detonator, and a second position within said self-destruct slide housing offset from said first position in a second direction in which said interlock unit allows said energizing source to move said self-destruct firing pin into said first detonator, and
an activation mechanism offset from said delay mechanism and supporting said interlock unit in said first position against said self-destruct firing pin, said activation mechanism adapted to shift after a delay and release its support of said interlock unit against said self-destruct firing pin to allow movement of said interlock unit to said second position.
2. The self-destruct detonating fuze of claim 1 , said slide housing holding member including a fuze housing, said fuze housing fixedly secured to the submunition and covering said stationary self-destruct slide housing, said fuze housing including a slide housing locking unit extending around and holding said self-destruct slide housing in the stationary position relative to the submunition.
3. The self-destruct detonating fuze of claim 2 , said slide housing holding member further including an arming screw, said stationary self-destruct slide housing including an aperture receiving said arming screw, said aperture being aligned between said arming screw and said second detonator when said movable fuze slide is in the armed position.
4. The self-destruct detonating fuze of claim 3 , said arming screw being engaged within said aperture of said self-destruct slide housing regardless of the position of the movable fuze slide.
5. The self-destruct detonating fuze of claim 1 , wherein the first direction is different that the second direction.
6. The self-destruct detonating fuze of claim 1 , said activation mechanism including a container holding a fluid, and a breaking member that breaks said container and accesses said fluid to erode said breaking member over the delay and release the support of said restraining unit against said self-destruct firing pin, said breaking member including a timing ball in contact with a piston, said timing ball adapted to break said container, access the fluid, erode when exposed to the fluid during the delay, and move into said container after the delay.
7. The self-destruct detonating fuze of claim 6 , wherein said activation mechanism further includes a second energizing source that causes the contact between said breaking member and said container.
8. The self-destruct detonating fuze of claim 7 , wherein said first energizing source and said second energizing source each include a compression spring.
9. The self-destruct detonating fuze of claim 7 , wherein said container is a glass ampoule and said breaking member is an ampoule weight that is urged by said second energizing source to contact and break said glass ampoule to access said fluid.
10. The self-destruct detonating fuze of claim 6 , said piston supporting said restraining unit during the erosion of said timing ball, and said piston releasing its support of said restraining unit when said timing ball moves into said container after the delay.
11. The self-destruct detonating fuze of claim 6 , further comprising a ribbon retainer that restricts an unfurling of a stabilizer ribbon prior to a deployment of the submunition, and that is extracted upon the unfurling of the stabilizer ribbon after the deployment.
12. The self-destruct detonating fuze of claim 11 , said activation mechanism further including a retainer clip that maintains separation between said container and said breaking member prior to a deployment of the submunition, said retainer clip abutting said breaking member and engaged with said ribbon retainer to extract from said breaking member upon the extraction of said ribbon retainer.
13. The self-destruct detonating fuze of claim 11 , wherein said ribbon retainer includes a movable slide lock housing said movable fuze slide and at least partially covering said stabilizer ribbon.
14. The self-destruct detonating fuze of claim 1 , wherein said slide housing includes a channel between said delay mechanism and said activation mechanism, and restraining unit includes at least one interlock ball that moves within said channel between the first position and the second position.
15. The self-destruct detonating fuze of claim 1 , said slide housing holding member including an arming screw, said stationary self-destruct slide housing including an aperture receiving said arming screw, said aperture being aligned between said arming screw and said second detonator when said movable slide is in the armed position, said arming screw slidingly engaged within said aperture to maintain alignment of said arming screw relative to said second detonator.
16. A self-destruct detonating fuze for a submunition, said submunition having a longitudinal axis, a main charge and said self-destruct detonating fuze for initiating the main charge upon impact, said self-destruct detonating fuze comprising:
a self-destruct slide housing holding a first detonator;
a movable fuze slide slidingly engaged with said self-destruct slide housing between a safe position and an armed position, said movable fuze slide having a second detonator mounted thereto;
a slide housing holding member permanently engaged with said self-destruct slide housing and holding said self-destruct slide housing in a stationary position relative to the submunition regardless of the position of said movable fuze slide;
said stationary self-destruct slide housing including
a delay mechanism offset and substantially orthogonal to the longitudinal axis, said delay mechanism including an energizing source and a self-destruct firing pin, said self-destruct firing pin aligned with said first detonator and urged into said first detonator by said energizing source;
an activation mechanism offset from said delay mechanism, said activation mechanism including a container holding a fluid, and a breaking member that breaks said container and accesses the fluid, which erodes said breaking member over a delay and releases a hold against said self-defense firing pin; and
an interlock unit movable between a first position supported by said activation mechanism against said self-destruct firing pin to hold said self-destruct firing pin away from said first detonator, and a second position that releases the hold against said self-destruct firing pin and allows said energizing source to move said self-destruct firing pin into said first detonator, the self-destruct slide housing including a channel between said delay mechanism and said activation mechanism, the interlock unit including at least one interlock ball that moves within said channel between the first position and the second position.
17. The self-destruct detonating fuze of claim 16 said slide housing holding member including a fuze housing, said fuze housing fixedly secured to the submunition and covering said stationary self-destruct slide housing, said fuze housing including a slide housing locking unit extending around and holding said self-destruct slide housing in the stationary position relative to the submunition.
18. The self-destruct detonating fuze of claim 16 , said slide housing holding member including an arming screw, said stationary self-destruct slide housing including an aperture receiving said arming screw, said aperture being aligned between said arming screw and said second detonator when said movable slide is in the armed position, said arming screw slidingly engaged within said aperture to maintain alignment of said arming screw relative to said second detonator.
19. The self-destruct detonating fuze of claim 18 , said arming screw being engaged within said aperture of said self-destruct slide housing regardless of the position of the movable fuze slide.
20. The self-destruct detonating fuze of claim 16 , said activation mechanism further including a second energizing source that urges said breaking member to contact and break said container to access said fluid, said breaking member including a timing ball in contact with a piston, said timing ball adapted to break said container, access the fluid, erode when in contact with the fluid during the delay, and move to the second position inside said container after the delay, said piston supporting said restraining unit during the erosion of said timing ball, and said piston releasing its support of said restraining unit when said timing ball moves to the second position, which releases the hold against said self-destruct firing pin and allows said energizing source to move said self-destruct firing pin into said detonator into said container.
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US12/855,997 US20120037028A1 (en) | 2010-08-13 | 2010-08-13 | Stationary self-destruct fuze mechanism |
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US12/855,997 US20120037028A1 (en) | 2010-08-13 | 2010-08-13 | Stationary self-destruct fuze mechanism |
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US12/855,997 Abandoned US20120037028A1 (en) | 2010-08-13 | 2010-08-13 | Stationary self-destruct fuze mechanism |
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US (1) | US20120037028A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110171511A1 (en) * | 2009-09-01 | 2011-07-14 | Omnitek Partners Llc | Compact and Low-Volume Mechanical Igniter and Ignition Systems For Thermal Batteries and the Like |
US20130152811A1 (en) * | 2009-09-01 | 2013-06-20 | Omnitek Partners Llc | Impulse-Based Compact Mechanical G-Switch With Modular Design |
CN113218258A (en) * | 2021-05-21 | 2021-08-06 | 南京理工大学 | Rotating rocket projectile warhead mechanical trigger fuse with self-destruction and floor-scrubbing blasting functions |
CN113935074A (en) * | 2021-09-17 | 2022-01-14 | 北京理工大学 | A safety control chip for memory transient self-destruction system |
CN114777582A (en) * | 2022-05-06 | 2022-07-22 | 南京理工大学 | A mechanical activation device for low-launch overload projectile heat-carrying battery |
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US3998164A (en) * | 1975-12-15 | 1976-12-21 | The United States Of America As Represented By The Secretary Of The Army | Self-destruct delay fuze |
US5932834A (en) * | 1997-04-24 | 1999-08-03 | The United States Of America As Represented By The Secretary Of The Army | Auto-destruct fuze |
US6050195A (en) * | 1998-12-03 | 2000-04-18 | The United States Of America As Represented By The Secretary Of The Army | Self neutralizing fuze |
US20070261586A1 (en) * | 2006-05-12 | 2007-11-15 | Day & Zimmerman, Inc. | Self-destruct fuze delay mechanism |
US20100258021A1 (en) * | 2009-04-10 | 2010-10-14 | Nexter Munitions | Ammunition firing device incorporating a firing pin |
US8082845B2 (en) * | 2006-12-28 | 2011-12-27 | Advanced Meterial Engineering Pte Ltd | Self destruction impact fuse |
-
2010
- 2010-08-13 US US12/855,997 patent/US20120037028A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
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US3998164A (en) * | 1975-12-15 | 1976-12-21 | The United States Of America As Represented By The Secretary Of The Army | Self-destruct delay fuze |
US5932834A (en) * | 1997-04-24 | 1999-08-03 | The United States Of America As Represented By The Secretary Of The Army | Auto-destruct fuze |
US6050195A (en) * | 1998-12-03 | 2000-04-18 | The United States Of America As Represented By The Secretary Of The Army | Self neutralizing fuze |
US20070261586A1 (en) * | 2006-05-12 | 2007-11-15 | Day & Zimmerman, Inc. | Self-destruct fuze delay mechanism |
US8082845B2 (en) * | 2006-12-28 | 2011-12-27 | Advanced Meterial Engineering Pte Ltd | Self destruction impact fuse |
US20100258021A1 (en) * | 2009-04-10 | 2010-10-14 | Nexter Munitions | Ammunition firing device incorporating a firing pin |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110171511A1 (en) * | 2009-09-01 | 2011-07-14 | Omnitek Partners Llc | Compact and Low-Volume Mechanical Igniter and Ignition Systems For Thermal Batteries and the Like |
US20130152811A1 (en) * | 2009-09-01 | 2013-06-20 | Omnitek Partners Llc | Impulse-Based Compact Mechanical G-Switch With Modular Design |
US8550001B2 (en) * | 2009-09-01 | 2013-10-08 | Omnitek Partners Llc | Compact and low-volume mechanical igniter and ignition systems for thermal batteries and the like |
US8869700B2 (en) * | 2009-09-01 | 2014-10-28 | Omnitek Partners Llc | Impulse-based compact mechanical G-switch with modular design |
CN113218258A (en) * | 2021-05-21 | 2021-08-06 | 南京理工大学 | Rotating rocket projectile warhead mechanical trigger fuse with self-destruction and floor-scrubbing blasting functions |
CN113935074A (en) * | 2021-09-17 | 2022-01-14 | 北京理工大学 | A safety control chip for memory transient self-destruction system |
CN114777582A (en) * | 2022-05-06 | 2022-07-22 | 南京理工大学 | A mechanical activation device for low-launch overload projectile heat-carrying battery |
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AS | Assignment |
Owner name: DAY & ZIMMERMANN, INC., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CHAMLEE, WILLIAM D.;SMITH, JERRY E.;FLOURNOY, BERRY W.;SIGNING DATES FROM 20100728 TO 20100802;REEL/FRAME:024834/0696 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |