Abstract: An initiator (14c) for a secondary explosive receptor charge is provided by forming a length of detonating cord (14) into a helical coil containing a plurality of windings with a cutoff barrier provided by, e.g., a separating rib (46) between adjacent windings. The adjacent windings may be not more than about 0.5 inch (12.7 mm) apart. The detonating cord (14) may be wound about a spindle (16) which may optionally provide the separating rib (46). The coil may be a tapered coil which may define a taper angle of e.g., from about 2 to 4 degrees. Alternatively, the coil may be a cylindrical coil, or the cord may be configured in a planar spiral. Optionally, the detonating cord in the helical coil may have a core of explosive material with a loading of less than 15 grains per foot of the cord, e.g., less than 12 grains per foot of the cord, or a loading in the range of from 8 to 12 grains per foot of the cord. The coil may consume about six inches of the cord.

Abstract: An explosive charge such as a cast booster charge (10, 110, 210) includes an explosive charge (14, 114, 214) having a first explosive matrix material (114a, 214a) with discrete bodies (118, 218) of a second material embedded therein. In some embodiments, discrete bodies may comprise explosive material and the first explosive matrix material (114a, 214a) may be more sensitive to initiation than the explosive material of the discrete bodies (118, 218). In a separate aspect of the invention, the discrete bodies may have a minimum dimension of at least 1 millimeter or, optionally, 1.6 millimeter, regardless of the explosive properties of the material therein. In a particular embodiment, discrete bodies may be shaped as cylindrical pellets rounded at at least one end. The cast booster charge (10, 110, 210) may be produced by melting the first explosive, disposing discrete bodies therein and cooling the molten material to solid form.

Abstract: A tubing and casing cutter is shown which can be assembled in the field from a plurality of pressed segmented pellets of free standing explosive material. The segmented pellets have a liner glued to at least one exposed face thereof. The pellets are glued to a backup plate with two mirror image plates being stacked to form a plate assembly. A plurality of plate assemblies are stacked within a surrounding container to form the cutter. The pressed pellets can also be assembled within a cup-shaped container to form a shaped charge.

Abstract: A gas generant material body in the form of a tablet having a triangular cross section and associated methods of gas generation are provided.

Abstract: Disclosed herein is a blasting apparatus for forming horizontal underground cavities and blasting method using the same. The blasting apparatus includes a metallic body horizontally formed through the center portion of a loading chamber. A delayed detonator and a shaped explosive are loaded in the loading chamber of the body. A connecting ring is formed on the body for connecting the body to a hoisting rope. The blasting method includes the step of loading a detonator lead, a delayed detonator and a shaped explosive in a loading chamber. The blasting apparatus is suspended over a vertical pit by operating a hoisting device. The blasting apparatus suspended by the hoisting rope is lowered to the entrance of a vertical pit, and a detonator lead drawn out of the body is connected to a leading wire. The blasting apparatus and the leading wire connected to the detonator lead drawn out of the body are lowered into the vertical pit at a position where fluid discharges.

Abstract: In ignition elements where the energy required to ignite the charge is produced using a laser source, the laser light is injected by means of an optical fiber or a laser optics system enabling the laser light to be focused onto the charge at the required intensity for ignition. Transmission losses and injection losses occur while the laser light is transmitted by means of optical devices or optical fibers. Known ignition devices are also complicated in terms of construction. According to the invention, the laser light source is a laser diode (3) and the explosive (4) that is to be ignited is arranged directly on the part (12) of the housing (8) of the laser diode (3) that allows the laser light (13) to pass through it.

Abstract: An electric actuated explosion detonator for use to detonate a confined explosive charge capable of being detonated by heat and/or shock, including an electrical resistor positioned in engagement with the confined explosive charge, the resistor having two electrical contacts and having a predetermined maximum electric current carrying capability and subject to receiving, by the application of an electrical energy source, sufficient voltage and wattage that an instantaneous current flow causes the resistor to instantaneously disintegrate.

Abstract: A system and method are disclosed for controlling the launch and burst of pyrotechnic projectiles in a pyrotechnic, or “fireworks”, display.

Abstract: The invention relates to a method of producing a screening smoke which is one-way transparent in the infrared spectrum (780 nm-14.0 &mgr;m) and opaque in the visible spectrum. According to the invention a known pyrotechnic screening smoke which is highly absorbent in the visible spectrum (380 nm-780 nm) is generated in the form of an aerosol, pyrotechnic scattered particles between 10 and 100 &mgr;m in size are simultaneously produced in said aerosol, and the resulting two-component smoke is irradiated by an infrared radiation source (spectrum: 780 nm-14.0 &mgr;m) from the smoke producer side.

Abstract: A priming unit, consisting of a combination of rested casings 5, 6, 7, a firing pin 3 with assembly aid 12, as well as a priming spring 8 and a propulsion spring 9, are arranged to provide a secure detonation of a fuze or bomblet fuze. The priming unit ensures a secure detonation upon impact with a target or at the completion of the flight phase. As a result, almost no duds are created. If, for any reason, the detonator carrier has not been armed, it is maintained in the unarmed position as a result of the arrangement, so that no dangerous duds result.

Abstract: Munitions are dropped from military aircraft to quickly combat large area fires within vast threatened regions. Each munition has a shell-shaped case having a chamber containing an air-bag power module and fire retardant. A lid closes one end of the chamber, and switches on the case provide signals for the air-bag power module to suddenly forcefully displace the lid from the chamber by the air-bag module and suddenly forcefully eject the fire retardant from the chamber and out of the case by the air-bag module. Munitions containing fire retardant can be targeted accurately at single hot spots, isolated structures, and along fire lines or can be quickly and accurately dropped to create a protected zone behind an area that has been made not to burn by munitions to protect fire fighters trapped in the path of runaway fires. Munitions are deployed from aircraft by military crewmen without requiring additional training.

Abstract: A shaped charge with enhanced performance is provided. In a disclosed embodiment, an oilwell perforator includes a liner which is formed of a metal powder. The metal powder has particles thereof which are coated with metal. The metal powder may be tungsten, and the particles may be coated with metals such as copper, lead, molybdenum, tin, nickel or silver. The resulting liner content by weight may be between approximately 95 and 100% tungsten.

Abstract: The invention relates to an electronically and mechanically-operated ignition delay which is used in cartridge-type pyrotechnic decoy flare ammunition. Said ignition delay comprises a cylindrical sleeve (10), containing an ignition device (1) in the base, a propellant (2) for expelling the inflammable active material (8) and devices (9) for delaying the ignition of the active material. The electric ignition device of the propellant charge is galvanically connected to a capacitor element (3) which is fixed in the propulsion reflector (4). Said capacitor element is galvanically connected to a mechanical switch-on element (7) in the active material, whereby said mechanical switch-on element is, in turn, galvanically connected to an electric ignition unit in the active material. The switch-on process is thus triggered by the relative movement of the active material as it travels along the sleeve axis away from the propulsion reflector.

Abstract: A method to form a sealed, partially or fully densified fiber reinforced composite preform which comprises: impregnating said preform with a major portion of a liquid, ceramic-forming precursor; initiating cure of the outer surface of said precursor with radiation, such as actinic radiation; a thereby forming a sealing barrier or skin on the surface of said preform. In a second embodiment the preform is infiltrated with a thermoplastic as liquid, frozen, excess frozen infiltrate optionally removed from the preform surface, then the preform is coated with a liquid which is curable with radiation, cure is initiated with radiation and the preform is sealed with a barrier coat.

Abstract: The present invention relates to the field of hybrid gas generators intended to inflate a protective airbag. The generator (1) consists of two metal tubes (50, 51) welded together, the upstream tube (50) being of one piece with an internal partition (26) that has a central orifice (27) closed by a diaphragm (28). The generator thus has a reservoir chamber (29) containing a pressurized gas and a combustion and mixing chamber (46) containing a pyrotechnic device (4) and a support piece (30) carrying a piston-pillar (31) the stroke of which is limited. The hot gases cannot enter the reservoir chamber (29) which may thus contain a greater amount of gas.

Abstract: A carrier for containing explosives (e.g., shaped charges) includes a housing having a plurality of recesses, each recess having a periphery and a side surface extending around the periphery. The side surface is shaped to a geometry to reduce or control reflection of compression waves generated in response to an explosive jet (e.g., a perforating jet) created due to detonation of an explosive. The side surface may be slanted from a bottom surface of the recess, or a predetermined profile may be formed in the side surface to scatter or direct compression waves. One or more shock absorbing inserts may also be placed in recesses formed by the inserts, or the recesses may be capped to trap air so that compression waves generated in the recesses are significantly reduced as compared to compression waves generated in well fluids.

Abstract: A method of blasting rock or similar materials in surface and underground mining operations is described in which neighboring bore holes are charged with explosives and primed with detonators. The detonators are programmed with respective delay intervals according to the firing pattern and the mineralogical/geological environment and the resulting seismic velocities.

Abstract: A launching device for launching multiple aerial fireworks in succession from the launching device has a tubular member having a wall defining an internal perimeter sized and shaped to receive conventional aerial fireworks shells. A unitary base is mountable to the tubular member to thereby support the tubular member in an upright use position on a support surface. The base includes a lower portion of appropriate size and shape to support the tubular member in a stable upright position; and a protrusion extends from the lower portion. The protrusion has an outer perimeter corresponding in size and shape to the inner perimeter of the tubular member to thereby permit snug insertion of the protrusion into the tubular member to secure it to the base.

Abstract: The invention of the present application provides a method of controlled blasting comprising dispersing an explosive (9) within a blasthole (1) to form a dispersed explosive having a lower average bulk density than said explosive (9) prior to dispersion and detonating said dispersed explosive. Typically the explosive (9) is dispersed in air, however the explosive (9) may be dispersed in other matrices such as other gases or liquids or in gases comprising particulate matter. The explosive (9) may be dispersed using a number of different techniques such as, using a discharge of pressurised fluid or by detonation of a small propellant charge or by falling under gravity in the blasthole. The invention of the present application is particularly useful where a reduced concentration of explosive energy is required such as in perimeter control, presplitting or soft rock conditions, can be controlled by a method which involves dispersion the explosives composition (9) within a blasthole prior to initiating the blast.

Abstract: A shaped charge capsule includes an open-ended casing and a ring. The casing is adapted to house an explosive, and the casing includes a shoulder to receive a cap to close the casing. A rim of the casing at least partially surrounds the shoulder. The ring is adapted to be placed radially inside the rim and crimped with the rim to secure the cap to the casing. The ring is adapted to melt above an approximate predetermined temperature to release the cap from the casing. The cap may alternatively be secured to the casing by an adhesive that decomposes above the approximate predetermined temperature threshold.