Abstract: A projectile fuze (12) having fuze electronics in which the time of flight (T) can be programmed, having a timer/counter which counts up to the programmed time of flight (T)—minus a defined time value (?t)—and then charges an electrical firing circuit, and having a mechanical safety and arming unit (16) which switches a firing chain to the armed position after a specific time interval. The firing chain has an electrical detonator (24), a fuze needle (20), a piercing detonator (22) and a booster charge (26). The projectile fuze (12) has a pyrotechnic force element (14), which is interconnected with the fuze electronics and mechanically blocks the safety and arming unit (16) until the time of flight (T) minus the predetermined time value (?t) is reached, after which the electrical firing circuit is charged and the safety and arming unit (16) is unlocked to the armed position by initiation of the force element (14).

Abstract: An improved fuze for a submunition grenade designed to be launched from a cargo projectile comprising a fuze, a charge and a casing; the improved fuze comprising a fuze housing; a threaded firing pin having a pointed tip, oriented coaxially with the submunition grenade, and threadedly engageable to a threaded hole in a weighted insert that is able to reciprocate within the fuze housing; a slider slidingly moveable in a substantially radial plane tangential to the axis of the firing pin, between a safe position and an armed position; the firing pin being able to rotatably reciprocate forwards and backwards by rotation of the firing pin with respect to the weighted insert along the threadedly engaged screw threads; the fuze further comprising a fully mechanical inertial releasable safety apparatus for preventing swiveling of the swivel mounted striker, to prevention initiation of the time delay detonator ignition system.

Abstract: The present invention is directed to a remote digital firing system for firing of a remote mission payload that includes a firing circuit communicatively coupled to and operative to fire the remote mission payload, a firing control panel communicatively linked to said firing circuit, and a digital code plug configured to be integrated in communicative combination with said firing circuit and said firing control panel, wherein said firing circuit is operative, with said digital code plug integrated in communicative combination therewith, to generate and write one-time random session variables to said digital code plug and to simultaneously store said one-time random session variables internally in said firing circuit; wherein said firing control panel is operative, with said digital code plug integrated in communicative combination therewith, to generate and transmit messages having said one-time random session variable embodied therein to said firing circuit; and wherein said firing circuit validates said mes

Abstract: A microscale firetrain for a safe and arm device having a safe position and an armed position, the firetrain including an input explosive column having a longitudinal axis; a transfer charge having a longitudinal axis and first and second ends and movable from a safe position to an armed position; a receptor charge having a longitudinal axis that is non-collinear with and substantially parallel to the longitudinal axis of the input explosive column; wherein, in the safe position, the transfer charge is remote from both the input explosive column and the receptor charge; and wherein, in the armed position, the input explosive column is adjacent the first end of the transfer charge to thereby initiate the transfer charge, the longitudinal axis of the input explosive column is substantially perpendicular to the longitudinal axis of the transfer charge, the second end of the transfer charge is adjacent the receptor charge to thereby initiate the receptor charge and the longitudinal axis of the receptor charge is

Abstract: A shell fuse has a target acquisition sensor, such as an impact sensor, and a firing train in which a firing device carrier is movable from a safe position into an armed position. Overflight safety all the way to the target is afforded in a simple manner. There is provided a force element, in particular a pyrotechnic trigger device, which can be initiated by the response of the sensor. The force element is coupled to the firing device carrier such that the firing device carrier is movable into the armed position.

Abstract: A microscale firetrain for a safe and arm device having a safe position and an armed position, the firetrain including an input explosive column having a longitudinal axis; a transfer charge having a longitudinal axis and first and second ends and movable from a safe position to an armed position; a receptor charge having a longitudinal axis that is non-collinear with and substantially parallel to the longitudinal axis of the input explosive column; wherein, in the safe position, the transfer charge is remote from both the input explosive column and the receptor charge; and wherein, in the armed position, the input explosive column is adjacent the first end of the transfer charge to thereby initiate the transfer charge, the longitudinal axis of the input explosive column is substantially perpendicular to the longitudinal axis of the transfer charge, the second end of the transfer charge is adjacent the receptor charge to thereby initiate the receptor charge and the longitudinal axis of the receptor charge is

Abstract: A two-stage acceleration sensing apparatus is disclosed which has applications for use in a fuze assembly for a projected munition. The apparatus, which can be formed by bulk micromachining or LIGA, can sense acceleration components along two orthogonal directions to enable movement of a shuttle from an “as-fabricated” position to a final position and locking of the shuttle in the final position. With the shuttle moved to the final position, the apparatus can perform one or more functions including completing an explosive train or an electrical switch closure, or allowing a light beam to be transmitted through the device.

Abstract: The present invention is directed to a remote digital firing system for firing of a remote mission payload that includes a firing circuit communicatively coupled to and operative to fire the remote mission payload, a firing control panel communicatively linked to said firing circuit, and a digital code plug configured to be integrated in communicative combination with said firing circuit and said firing control panel, wherein said firing circuit is operative, with said digital code plug integrated in communicative combination therewith, to generate and write one-time random session variables to said digital code plug and to simultaneously store said one-time random session variables internally in said firing circuit; wherein said firing control panel is operative, with said digital code plug integrated in communicative combination therewith, to generate and transmit messages having said one-time random session variable embodied therein to said firing circuit; and wherein said firing circuit validates said mes

Abstract: An igniter for a flare that includes a housing and a slider assembly. The housing includes an ignition device portion and a slurry groove portion. The ignition device portion has an ignition device portal for holding an ignition device, while the slurry groove portion has a groove for ignition slurry. The slider assembly is disposed within the housing, the slider assembly has an armed position and a safe position, the armed position not covering the ignition device portal allowing the ignition device disposed within the ignition device portals to ignite the ignition slurry, which ignites the flare, the safe position covering the ignition device portal and preventing ignition of the flare.

Abstract: The invention provides a safety system for a small arms projectile in which an initiating device is impacted by a firing member in order to detonate a main explosive charge. The system requires the firing member to be retained in a safe position in relation to the initiating device by at least two independent mechanisms. The firing member is initially supported in a forward position, in which it assists in holding the initiator device in a safe condition, and is caused to move rearwardly, through inertia, when the projectile is fired, destroying one of the retaining mechanisms and allowing the initiator device to adopt a primed position in which it can be activated by the firing member which at this time is retained by the other retaining mechanism which is automatically released when the projectile is in flight.

Abstract: The invention aims to increase the overflight safety of a projectile, comprising a time-fuse which has an acceleration-activated battery. To this end, the safety device actuates a switch, whose position is interrogated during the flight phase and the fuse function is deactivated, if the switch is not in the correct position.

Abstract: A MEMS type safe and arm apparatus for a fuze includes a setback slider responsive to a first setback acceleration, the setback slider moving linearly in response to the first setback acceleration; a setforward slider responsive to a first setforward acceleration, the setback slider unlocking the setforward slider, the setforward slider moving linearly in response to the first setforward acceleration; a first rotor responsive to a second setback acceleration, the setforward slider unlocking the first rotor, the first rotor rotating in response to the second setback acceleration; a second rotor responsive to a second setforward acceleration, the first rotor unlocking the second rotor, the second rotor rotating in response to the second setforward acceleration; and an arming slider that moves linearly in response to the rotation of the second rotor to thereby arm the fuze.

Abstract: Miniature arm fire and safe and arm devices include an electrically operated pyrotechnic initiation device (5) to generate a detonation wave upon command and a movable pressure barrier (9) that blocks propagation of the detonation wave if the device is not intended to be fired and opens a window (12) to transfer the detonation wave externally of the device. The detonation wave may in alternate embodiments be a subsonic flame front and pressure wave or a supersonic shock wave, respectively. An electromagnet (7) may serve to move the pressure barrier. Detonation waves output from the device have application in igniting an explosive train, either directly or indirectly, the latter by operating an electrical switch. In the arm fire device, the barrier automatically prevents a detonation output when electrical power is removed from the device. In the safe and arm device, the barrier, once moved out of the way, remains out of the way, even when electrical power is removed.

Abstract: A disarm mechanism to maintain a safe work area for individuals that may be working in such area which allows for the remote disarming of an article of explosive equipment by remotely shifting a switch of an explosive circuit to an off or non-operative position. Said switch is connected in series with a detonator and along with an explosive charge housed within an extinguishant container from which extinguishant would normally be dispelled when the explosive circuit is activated. After switching, a lock-out device is secured to the disarm mechanism such that the switch cannot be shifted to the on or operative position without removal of such lockout. Visual indicia is provided to alert the operator as to the position of the control switch.

Abstract: A miniature, planar, inertially-damped, inertially-actuated delay slider uator is micromachined on a substrate and consists of a "slider", with zig-zag or stair-step-like patterns on the side edges, interacting with similar vertical-edged zig-zag patterns on "racks" which are positioned across a small gap on each side. The slider has been released from the substrate, and is captured vertically in its track by a non-interfering lattice or cover or other feature that bridges across from the top of one rack to the other. The racks are fixed to the substrate and the slider is forced axially down the "track" by an inertial load in the slider's axial direction. The slider is drawn along the track such that the "teeth" on the right edge of the slider engage with the teeth on the right rack. The slider is forced to move to the left as it slides down the faces on the right rack, until it is thrown clear of the right rack and goes across to engage similarly with the left rack.

Abstract: A method and an apparatus for use in a wellbore are provided to prevent an electrical current from passing between a power supply and an electrically operated downhole well tool until after the electrically operated downhole well tool is positioned downhole within the wellbore. A temperature sensitive member prevents a biased member from moving from a first position to a second position until after the temperature sensitive member has been heated to an activation temperature, at which the temperature sensitive member softens to allow the biased member to move through the temperature sensitive member and to the second position for electrically connecting between the power supply and the electrically operated downhole well tool.

Abstract: The ignition safety device is mounted on a rocket motor nozzle having a body with a longitudinal nozzle opening having an igniter therein for igniting the propulsion charge of the rocket motor. An electrically operable detonator is mounted in a detonator opening in a housing mounted in the body. An actuator and a locking member are movable in the body between safe and armed positions. The locking member has means operative in its safe position for locking the actuator. Movement of the locking member to its armed position unlocks the actuator. A spring biases the locking member to its safe position. The actuator is adapted to operate a switch which initially short circuits the electrically operable detonator but is operable by the actuator to an armed position in which the detonator is no longer short circuited and is connected to an electrical input circuit including a contact band on the nozzle body.

Abstract: A safe-and-arm device with a series connection formed through a switch which is activated through triggering criteria and which is connected ahead of a detonator for a secondary explosive, especially for utilization with a submunition projectile. Hereby, a switching element of a first switch is arranged on a first carrier or support for the switching element which is slidable from its blocked secured or safe position through the intermediary of a power element which is initiated by a releasing criterium into armed position, and a switching element of a second switch is arranged on a support for this switching element which is coupled with the support of the first switching element and displaceable by the latter from its safe position across an interim position into its armed position in the presence of a further releasing criterium.

Abstract: In the representative embodiments of the several methods and apparatus of the invention, a barrier formed of a low-temperature fusible metal alloy having a selected melting point greater than the anticipated well bore temperatures is arranged between a receptor explosive and a typical electrically-initiated detonator enclosed in a housing for blocking the transmission of detonation forces from the detonator to the receptor explosive until the barrier has been heated by an electrical heater adjacent to the barrier. By selecting a fusible metal alloy which has a melting point higher than the known temperatures of the well bore fluids, when the tool is exposed to those elevated temperatures, the barrier will be predictably maintained in its solid state to continue blocking the detonation path of the donor explosive if the heater fails thereby allowing the well tool carrying the explosives to be safely recovered from the well bore.

Abstract: In the representative embodiments of the several methods and apparatus of the invention, a barrier formed of a low-temperature fusible metal alloy having a selected melting point is arranged between a receptor explosive and a typical electrically-initiated detonator enclosed in an explosion-proof housing for blocking the transmission of detonation forces from the detonator to the receptor explosive until the detonator has been subjected to well bore temperatures which are greater than the melting point of the fusible alloy. By selecting a fusible metal alloy which has a melting point less than the known temperatures of the well bore fluids, when the tool is exposed to those elevated temperatures, the barrier will be predictably transformed to its liquid state thereby allowing the liquid alloy to flow to a non-blocking position away from the detonation path of the donor explosive.

Abstract: In the representative embodiments of the several methods and apparatus of the invention, a barrier formed of a low-temperature fusible metal alloy having a selected melting point is arranged between the donor and receptor explosives in an otherwise-typical detonator for reliably blocking the transmission of detonation forces from the donor explosive to the receptor explosive until the detonator has been subjected to well bore temperatures which are greater than the melting point of the fusible alloy. By selecting a fusible metal alloy which has a melting point less than the known temperatures of the well bore fluids, when the tool is exposed to those elevated temperatures, the barrier will be predictably transformed to its liquid state thereby allowing the liquid alloy to flow to a non-blocking position away from the detonation path of the donor explosive.

Abstract: A shotgun cartridge (1) has an armour piercing shell (11) which includes a main charge (17) arranged to be detonated or exploded by direct percussion of a primer (12). The cartridge (1) includes a bore safe cylindrical arming device (16) integrally formed with the obturator (6), which interrupts the detonation process after detonation of the primer (12). The arming device (16) is arranged to separate from the shell, to arm the shell, after firing of the shell (11) from the barrel of a gun, and the shell (11) includes an open base or rear portion to prevent shrapnel being thrown to the rear on detonation.

Abstract: An ammunition unit has a fuze which includes an electrical trajectory safety device for preventing arming of the ammunition unit within a trajectory safety distance. An arming igniter actuable by the electrical trajectory safety device activates a movable portion for execution of an instantaneous movement to move a bursting cap disposed in the movable portion into an arming position in register with the initiation detonator included in a detonation chain and actuable by an impact or a proximity fuze contact. The movable portion is lockable by a locking pin, which is actuable on a retardation of the ammunition unit caused by a first hit of the ammunition unit against a first object located within the trajectory safety distance. Upon actuation, the locking pin locks the movable portion to prevent it from executing the instantaneous movement, even if the first hit were to cause mechanical action on the electronics which effects actuation of the arming igniter.

Abstract: A fuse is capable of installation in a warhead only when a rotor of the fuse is in its safety position. If the rotor is in its live position, installation in the fuse is not possible. The fuse comprises an installation safety element which is movable between a normal first position blocking installation of the fuse and a second position permitting such installation. In its live position, the rotor blocks movement of the element to its second position. When in its second position, the element does not interfere with movement of the rotor to a live position.

Abstract: A combined warhead arming and drive motor ignition device for a self-propelled missile having a warhead and a drive motor comprises a first acceleration responsive means (1, 2, 3, 4) to provide an output when the missile achieves a first acceleration, a timer initiated by the output from the first acceleration responsive means and providing a first output (i) after expiry of a first period and before expiry of a second period and a second output (v) after expiry of a third period, and a speed responsive means (5, 6) to provide a speed output (ii) when the missile has attained a predetermined speed and also to provide a first distance indication output (vi) when the missile has travelled a first distance but has not yet travelled a second distance and a second distance indication (vi) output when the missile has travelled a third distance.

Abstract: A unique signal, safe and arming device for preventing the inadvertent detonation of an ordnance, having an initiator barrier disk and an ignitor barrier disk situated adjacent respective opposite open ends of at least one transfer tube containing an initiator therein. The barrier disks are interconnected to move in synchronism with each other from a first position blocking the ends of the transfer tube to a second position unblocking the ends of the transfer tube. A maze-like slot is located within the ignitor barrier disk and a peg operably engages the maze-like slot. While the ignitor barrier disk moves from its first position to its second position under the control of preselected signals, the peg moves radially within the slot also under the control of preselected signals. This arrangement requires the proper input signals for the appropriate movement of both the peg and ignitor barrier disk in order to permit activation of the initiator to take place.

Abstract: A missile safe and arm system incorporates an electrically triggered explosive train that extends from the missile body to an extendable probe and back to the missile body. When the probe is in its retracted position, the explosive train, and electrical triggering circuit is interrupted and detonator firing leads are shorted and the missile is in a safe condition. Upon launching and upon the extension of the extendable probe, the explosive train and its electrical triggering circuit become aligned, the detonator shorting lead is removed, and the missile is thus armed.

Abstract: A unique code device for use with explosive devices. A stepping motor is vided with a shaft for rotation a predetermined number of times for arming the explosive device. Magnetic damping (braking) means is provided to constrain rotation of the shaft.

Abstract: A compact safety device for a fuse or detonator for a weapon such as a bastic projectile to be fired or launched from a tube, is protected against the propellant charge gas pressure by a lightweight, yet pressure tight housing provided with double closure members. One arming detonator element out of a chain of such elements is mounted on a rotor in the pressure tight housing. The rotor is rotatable between an armed position and a disarmed position. The rotation of the rotor is controlled by separate safety elements so that the fuse or detonator can be armed only when it is installed in a weapon.

Abstract: An improved construction for a percussion fuse. The fuse function has a firing pin rigidly mounted in an ignition head an adapted to coact with a percussion cap mounted in an impact member. This impact member is securedly maintained in a first position by means of at least one blocking sphere which is partially mounted in an annular groove of the impact member and partially mounted in a bore of the cylindrical forward portion of the percussion fuse body. A movable inertial sphere is disposed in a chamber between the impact member and the ignition head. In order to improve the fail-safety there is mounted in this chamber a housing between the impact member and ignition head which is coaxially movable with respect to the firing pin.

Abstract: A slideably mounted interrupter, or barrier, is constructed to interrupt or break a detonating train when held in a first position by a leaf spring in an unflexed mode, and to complete the detonating train when the interrupter is moved, by a predetermined amplitude of impact force, to a second position wherein the leaf spring is flexed and firmly wedged into a channel to prevent the interrupter from bouncing or otherwise moving out of the second position.

Abstract: The invention deals with an impact igniter (1) for projectiles with a fuse (15) acting as a transport safety and delayed arming device. By partitioning off the fuse (15) and the striker pin (7, 17) located behind it forward in the projectile trajectory direction, and by leading some of the surrounding air which streams past the projectile, against the fuse (15) through channels (24, 31) angled in relation to the trajectory direction, the igniter has been made rain-safe without extending the arming time unacceptably.

Abstract: A percussion fuse for artillery training ammunition such as mortar and howitzer projectiles. The training fuse assembly includes a body adapted for connection to a projectile body, a composition signal charge mountable within the fuse body and emitting report, smoke, and flash signals, and a striker unit for detonating the signal charge upon impact with a desired target. A combination safety system prevents premature detonation of the charge during handling, transportation, loading, and initial in-flight upward travel of the projectile. The fuse only becomes fully armed when the projectile reaches its terminal velocity and begins its downward flight toward the designated target. The armed fuse is highly sensitive and even upon impact with water will detonate in super quick fashion to discharge the entire signal before the projectile disappears below the surface of the water.

Abstract: A latch device in which movement of a shutter from a first to a second position is controlled by two latches in turn controlled by separate timers, the arrangement being such as to prevent the shutter reaching the second position unless the latches are operated in the correct sequence and the time between operation is above a nominal small value.