Abstract: A MEMS fuze having a moveable slider with a microdetonator at an end for positioning adjacent an initiator. A setback activated lock and a spin activated lock prevent movement of the slider until respective axial and centrifugal acceleration levels have been achieved. Once these acceleration levels are achieved, the slider is moved by a V-beam shaped actuator arrangement to position the microdetonator relative to a secondary lead to start an explosive train in a munitions round.

Abstract: A MEMS mechanical initiator having a striker arm extending from a striker body. The tip of the striker arm is adjacent to, but does not touch, the side of a microdetonator. A cocking and release mechanism moves the striker body such that the striker arm pulls away from the side of the microdetonator against the action of a set of springs connected to the striker body. Thereafter the cocking and release mechanism releases the striker body such that the tip of the striker arm swipes the side of the microdetonator causing initiation thereof.

Abstract: A MEMS fuze having a moveable slider with a microdetonator at an end for positioning adjacent an initiator. A setback activated lock and a spin activated lock prevent movement of the slider until respective axial and centrifugal acceleration levels have been achieved. Once these acceleration levels are achieved, the slider is moved by a V-beam shaped actuator arrangement to position the microdetonator relative to a secondary lead to start an explosive train in a munitions round.

Abstract: Microelectromechanical (MEM) safe-arm devices comprise a substrate upon which a sense mass, that can contain an energetic material, is constrained to move along a pathway defined by a track disposed on the surface of the substrate. The pathway has a first end comprising a “safe” position and a second end comprising an “armed” position, whereat the second end the sense mass can be aligned proximal to energetic materials comprising the explosive train, within an explosive component. The sense mass can be confined in the safe position by a first latch, operable to release the sense mass by an acceleration acting in a direction substantially normal to the surface of the substrate. A second acceleration, acting in a direction substantially parallel to the surface of the substrate, can cause the sense mass to traverse the pathway from the safe position to the armed position.

Abstract: A MEMS type safety and arming device includes a substrate; a frame disposed on the substrate; a setback slider disposed in the frame, the setback slider moving linearly in response to a setback acceleration; an arming slider disposed in the frame, the arming slider moving linearly in an arming direction perpendicular to the direction of the setback acceleration and in response to spin; a setback lock lever disposed in the frame, the setback lock lever engaging the arming slider to prevent linear motion of the arming slider until the setback slider contacts and moves the setback lock lever; and a command lock rocker disposed in the frame, the command lock rocker engaging the arming slider to prevent full arming motion of the arming slider until after the command lock rocker is actuated.

Abstract: A projectile fuze includes a detonator carrier having a safety position and an armed position; a pin having a blocking position in which it holds the detonator carrier in the safety position and a releasing position in which the pin allows the detonator carrier to move into the armed position; a spring urging the pin into the releasing position; a pyrotechnical delay element exposed to hot propellant gases for causing ignition and combustion of the delay element; and a pin-supporting component maintaining the pin in the blocking position against a force of the spring. The pin-supporting component is held in the pin-maintaining state by the delay element until combustion thereof, whereby the pin is allowed to move into the releasing position upon combustion of the delay element.

Abstract: A self destructing impact fuse including a cylindrical firing pin having a hollow centrifugal chamber for holding a number of spheres and a number of radial openings on its surface for exposing portions of the spheres when the chamber is spun. At one end of the chamber is a spring for exerting compression force along the longitudinal axis of the chamber and at the other end is a self-destructing (SD) firing pin for striking the detonator. A centrifugal lock having a pivot offset from the longitudinal axis holds the chamber in place by mating with a groove on the surface of the centrifugal chamber. The cylindrical firing pin is seated concentrically within a frame and disposed over an escapement assembly featuring the detonator. The detonator is rotated into alignment with the SD firing pin after the projectile, incorporating the fuse, travels the minimum tactical distance. The frame is further coupled with a base, which features a point detonation (PD) firing pin for striking the detonator.

Abstract: A shock tolerant fuze includes a detector for determining when fuze timing should be initiated, a movable safe and arm assembly containing a time delay circuit and a firing aperture. The firing train detonator is preferably also mounted on the movable armature. When the fuze is armed, the time delay circuit is coupled to the detector and to the detonator, and the aperture provides a pathway between the output of the detonator and the remainder of explosive firing train of the weapon. Electrical energy storage is provided on the armature for powering the time delay circuit and the detonator in the event that primary power thereto is interrupted by impact. By including the time delay circuit and energy storage on the movable armature, a very shock tolerant fuze is obtained.

Abstract: An ignition and safety device for a grenade projectile provided with a shaped charge insert and having a bottom-side impact fuse that has a spin-dependent safety element and acceleration-dependent safety element (14, 17), and a self-destruct device. The self-destruct device includes a pyrotechnical delay segment (29) that is axially displaceable into engagement with a firing pin (30) by means of the launch acceleration and acts on a booster charge (8), which is disposed extremely off-center of the projectile axis for the projectile effective charge. Consequently, no shaped charge jet is formed during self-destruction for the projectile.

Abstract: The objectives of these inventions are to provide simple, reliable, and low-cost mechanical means to obtain (1) second impact detonation and (2) substantial safe arming separation from the gun for point detonating fuzes for small caliber spin stabilized shell. The first objective is attained by use of a heavy shield over the firing pin which is removable between the first and second impacts by spin forces; the second objective is attained by a centrifugally driven rotor, containing the out-of-line explosive element, which deforms a ductile material to effect the arming delay.

Abstract: A pyrotechnic chain igniter device for cargo warhead sub-ammunition including an explosive charge contained in an enclosure, comprising a first striker mobile in a longitudinal bore of a body for striking a primer, a slider carrying the primer, the slider being slidably mounted in a transverse groove in the body and being adapted for sliding between a safety position and an armed position, wherein the safety position is defined by the slider being misaligned with the first striker and the armed position is defined by the primer being substantially aligned with the first striker. The first striker is adapted for striking the primer when the slider is in the armed position and when the sub-ammunition impacts a target. At least one device for blocking the slider in the safety position is provided.

Abstract: A grenade projectile has a projectile housing having a fragmentation length portion; an explosive charge accommodated in the projectile housing and being surrounded by the fragmentation length portion; a forwardly acting shaped charge liner bounding the explosive charge at a front end thereof, as viewed in the flight direction of the projectile; and a percussion fuse assembly accommodated in the projectile housing behind the explosive charge as viewed in the flight direction. The percussion fuse assembly includes a percussion member, a flight acceleration-responsive first safety arrangement and a centrifugal force-responsive second safety arrangement for arming the percussion member when the projectile reaches a predetermined acceleration and a predetermined spin.

Abstract: An after-firing safety device in a projectile with percussion fuze includes a spiral spring set having at least three springs wound up in series with respectively opposite directions. The spring set, maintained under tension by a cage, starts to uncoil as soon as the cage slides off the spiral spring set on account of the acceleration of the projectile during firing. The time elapsing until a central aperture has been entirely vacated depends on the number of springs, the spring lengh, the spring tension, and the friction characteristic. The after-firing safety device is equally well suited for spinning projectiles as well as nonspinning projectiles.

Abstract: The invention relates to a safe and arm mechanism for an exploding projectile to be fired from a rifled gun. The projectile first experiences axial and angular acceleration which moves a setback ball to initially arm the mechanism. A third projectile parameter, angular velocity, functions to lock the ball in the armed position. During projectile flight, a spin actuated escapement mechanism moves toward a fully armed position, but may be precluded from reaching that fully armed position by a command arm arrangement. The projectile is then fully armed when a command arm signal releases the arrangement and the escapement mechanism is allowed to complete its motion to the fully armed position. When the projectile strikes a target, it experiences axial deceleration which moves a contact ball partway to a detonating position. After the projectile passes through the target surface and into a void, e.g.

Abstract: The invention relates to a safe and arm mechanism for an exploding projectile to be fired from a rifled gun. The projectile first experiences axial and angular acceleration which moves a setback ball to initially arm the mechanism. A third projectile parameter, angular velocity, functions to lock the ball in the armed position. During projectile flight, a spin actuated escapement mechanism moves toward a fully armed position, but may be precluded from reaching that fully armed position by a command arm arrangement. The projectile is then fully armed when a command arm signal releases the arrangement and the escapement mechanism is allowed to complete its motion to the fully armed position. When the projectile strikes a target, it experiences axial deceleration which moves a contact ball partway to a detonating position. After the projectile passes through the target surface and into a void, e.g.

Abstract: A safing and arming (S&A) device 20 for a spin stabilized projectile 16 having an electronic fuzing system 18 which produces an electrical arming signal after the projectile 16 is fired. The cylindrical S&A housing 26 has two faces 28, 30 and a blow through hole 32 through the center of housing 26. A barrier recess 34 is formed in one face 28 of the housing 26 and a detonator 40 is mounted on the other face 30 and in alignment with the blow through hole 32. A barrier 36 is pivotally mounted in the barrier recess 34. Barrier 36 is held in its safe position blocking blow through hole 32 by a set back tab 54 and a barrier latch 48. The set back tab 54 is rendered inoperative when projectile 16 is fired from a gun. Latch 48 is bent out of contact with barrier 36 by a pyrotechnic actuator 56 being activated by the arming signal. When latch 48 is disengaged from the barrier 36, barrier 36 is free to move to its armed position, in which barrier 36 no longer blocks blow through hole 32.

Abstract: A safety device for a fuze of a spinning projectile comprises a spin acceleration safety element and a firing forward acceleration safety element. The firing forward acceleration safety element contains a ball displaceable by the action of the firing forward acceleration. The spin acceleration safety element employs an escapement or delay mechanism including an asymmetrically structured balance wheel whose center of gravity is radially displaced from its pivot axis such that the escapement or delay mechanism can begin to operate and time out only after the spin acceleration has ceased to be effective.

Abstract: In a weapon subject to a sequence of high acceleration followed by high spin and including a detonator and an explosive charge; the improvement comprising a barrier located between the detonator and explosive charge to normally form an obstruction to prevent accidental detonation of the explosive charge by the detonator. Mechanical locking means are provided to lock the barrier in place, comprising a spirally wound ribbon, a pair of pins restraining the outer surface of the ribbon to prevent premature unwinding, and a pair of superimposed anti-friction balls mounted on a hub portion of the ribbon, the upper ball being seated in an extension portion of the barrier. When the weapon is fired from a gun, the high acceleration will remove the pins and allow the ribbon to unwind. Upon unwinding the entire ribbon, the balls will be released and the barrier under the action of spin, will be removed to provide an unobstructed path between the detonator and explosive charge.

Abstract: A fuse for a spinning projectile comprises a rotor having safety elements which prevent rotation of the rotor to an active position. The safety elements are arranged such that when the safety elements are properly installed, the center of gravity of the rotor induces rotation of the rotor in a first direction toward the active position. An escapement mechanism regulates the rate of rotation of the rotor in such first direction. A stop prevents rotation of the rotor in the opposite direction. When a safety element is missing, the center of gravity is positioned to induce rotation of the rotor in such opposite direction in which the rotor cannot rotate.

Abstract: A fuze includes a conically shaped body having a central longitudinal chal communicating with a rearward central chamber, a firing pin assembly containing a primary and a biased secondary firing pin disposed in the channel, a delay arming assembly disposed in the chamber, a sleeve containing a setback locking assembly disposed in chamber, and a pyrotechnic smoke cartridge located in the hollow of the sleeve. The arming assembly contains two V-shaped pivotable levers held in the safe position by the secondary firing pin extending into a hole in each lever and by a detent pin extending into a hole in the lower lever, each lever having a hole containing a firing ball. On firing the projectile from the gun, the biased detent pin is withdrawn by setback force and the detents on the secondary firing pin are withdrawn by centrifugal force, releasing both levers to pivot by centrifugal force and align the firing balls with the firing pins and the cartridge primer.

Abstract: A safety apparatus for a spinning projectile fuze comprises a rotor with which there is operatively associated a toothed segment which, under the action of the spin, drives a retarding or restraining mechanism and following expiration of the action of the retarding mechanism moves the rotor into its armed or live position. The safety apparatus further comprises a spin safety element and an acceleration-spin safety element. The acceleration-spin safety element contains a ball displaceable by the action of the firing acceleration, and a disc member, and the spin safety element possesses a piston displaceable by the action of the projectile spin in order to release the rotor.

Abstract: A fuse provided with a detonator which is ignited by an electrical ignition signal is described. The detonator has a first terminal normally connected to earth and supported by a rotatable member which can move the detonator from a first position in which it is unable to transmit ignition to the chain, to a second position in which a second terminal thereof is in contact with a contact element at which the ignition signal arrives. The rotatable member is rotated by the centrifugal and inertia forces acting on the fuse and is controlled by a delay device arranged to allow it to rotate in a predetermined time and during at least part of the rotation of the rotatable member, the second terminal of the detonator is maintained in electrical contact with the earth so as to make the detonator electrically inactive during the part of the rotation.

Abstract: This is a new point-detonating fuze for spin-stabilized munitions. The fuze has three modules housed in a two-piece body, designed to optimize the penetration capability and to adjust the weight of the fuze. The upper body carries the point-detonating module which has a double-initiation feature, designed to function on impact against the target but preventing detonation on impact against rain droplets and against the foliage of wooded areas. The explosion, initiated at the top of the point-detonating module, is propagated by a mild-detonating fuze, first axially inside the shaft of the point-detonating module, then axially through the time-delay module, to reach the detonator in the safing-and-arming module. The point-detonating module acts as a selector designed to provide either a super-quick function or a time-delay function with several time-delay options. The desired choice is made by rotating the moving portion of the time-delay module to one of several pre-indexed positions.

Abstract: The invention relates to a safety device for a pyrotechnic assembly in a projectile, comprising a fire-screening flap disposed between an ignition primer and explosives, said flap being mounted so as to be escapable under the action of a mechanism provided with a regulator, said regulator being mounted on said flap itself.