Abstract: A temperature fuse for gas-generating mixtures consists of substances or mixtures of substances that have lower detonation points or decomposition points than the gas-generating mixture. In particular, the temperature fuse contains substances or mixtures of substances that thermally decompose exothermically in a narrowly restricted temperature range. The evolution of heat that results ignites the gas-generating mixture.

Abstract: A shaped-charge projectile includes a container in the form of a hollow shell elongated parallel to a projectile axis, with the container having a front end and a back end. A shaped-charge liner is within the container and adjacent to the front end of the container. The shaped-charge liner is a composite material of fibers or particles of a solid reinforcement dispersed in a solid amorphous matrix. An explosive charge is positioned between the shaped-charge liner and the back end of the container. The shaped-charge liner is preferably prepared by infiltration or casting, and assembled with the other elements to make the shaped-charge projectile.

Abstract: A tubular charge holder assembly for a perforating gun made of a tube having a plurality of pairs of diametrically opposed openings. The pairs of openings are formed over a length of the tube, wherein the each pair has a larger and a smaller opening. A shaped charge is located within the pairs of openings in the tubular charge holder so that at least a portion of the rim of a front face of the shaped charge extends out of the larger opening and at least a portion of a rear face of the shaped charge extends out from the smaller opening of the tube. A detonating cord is helically wrapped around the outside surface of the tube such that the detonating cord is positioned so that the cord is proximate to the rear surface of each of the shaped charges installed within the tube. A substantially semi-circular clip is positioned on the outside surface of the tube proximate each of the shaped charges.

Abstract: The invention disclosed is an apparatus for explosive blast suppression, and a method therefor, the apparatus comprising a hemispherical enclosure (10) defined by an upstanding wall, positioning means (42) associated with the enclosure, for positioning the explosive device substantially equidistant from any point on the wall, and in a preferred embodiment includes an integral floor (40) and a rounded lower wall, to provide a substantially even distribution of blast forces in all directions toward the wall. The enclosure is made of composite textile material, comprising one or several layers of a ballistic material (e.g. Dyneema Kevlar) sandwiched between inner and outer layers of a light-weight rip-stop nylon fabric material.

Abstract: A cartridge containing an explosive charge is inserted at the bottom of a short hole drilled in the rock. The cartridge is held in place or stemmed by a massive stemming bar of high-strength material such as steel. The cartridge incorporates additional internal volume designed to control the application of pressure in the bottom hole volume by the detonating explosive. The primary method by which the high-pressure gases are contained in the hole bottom until relieved by the opening up of controlled fractures, is by the massive inertial stemming bar which blocks the flow of gas up the drill hole except for a small leak path between the stemming bar and the drill hole walls. The stemming bar is preferably connected to a boom mounted on a carrier. A preferred embodiment incorporates an indexing mechanism to allow both a drill and a small-charge blasting apparatus to be used on the same boom for drilling and subsequent charge insertion and firing operations.

Abstract: A propellant grain for a cylindrical casing has a cavity including an axially central opening with a combustion product exit port at one end. The grain bears a plurality of surfaces extending circumferentially about and disposed normally or helically to this opening so as to define, between these surfaces and axially of the casing, alternating sections of propellant and sections of a groove or grooves in the propellant. The groove sections extend radially from the opening to a distance selectable to provide the grain with a large initial surface area while providing a high propellant volume.

Abstract: Disclosed herein is a center-cut blasting method for tunnel excavation. The center-cut blasting method includes the step of drilling a single central center-cut hole at the center of a center-cut region, drilling a plurality of auxiliary center-cut holes comprised of large unloaded auxiliary holes and loaded auxiliary holes that are alternately arranged around the central center-cut hole to be situated in a circle having a predetermined diameter, and drilling a plurality of spreader center-cut holes outside the auxiliary center-cut holes to be situated in concentric circles centered by the central center-cut hole. Thereafter, the center-cut holes are loaded with delay detonators and explosives and the center-cut holes are stemmed with stemming material at their entrances. The loaded auxiliary holes of the auxiliary center-cut holes are blasted so as to create a circular pre-split. After that, the central center-cut hole is blasted so as to create initial dual free surfaces.

Abstract: A device, system and method permitting on-line explosives-based cleaning and deslagging of a fuel burning facility (31) such as a boiler, furnace, incinerator, or scrubber. A coolant, such as ordinary water, is delivered to the explosives (101) to prevent them from detonating due to the heat of the on-line facility. Thus, controlled, appropriately-timed detonation can be initiated as desired, and boiler scale and slag is removed without the need to shut down or cool down the facility.

Abstract: Supplying a predetermined amount of electric energy to a fine metal wire 4 in a short time causes the fine metal wire 4 to melt and evaporate. Following this phenomenon, a blasting substance 10 expands in volume, so that the evaporative expansion force resulting from the melting evaporation of the fine metal wire 4 is transmitted to and blasts a to-be-blasted object 5.

Abstract: Pyrotechnic compositions having combustion reaction products that include a high percentage of carbon dioxide at high temperatures. These pyrotechnic compositions include a fuel component having combustion product with a relatively high percentage of carbon to hydrogen content, such as an aromatic polycarboxylic anhydride fuel component. These pyrotechnic compositions may be employed to emit infrared radiation from a decoy flare or other device. The compositions may also be employed as a gas generating propellant for a projectile, such as a flare or rocket, or for other applications such as an automobile airbag. These pyrotechnic compositions emit infrared emissions with minimized short wavelength components, and produce substantially non-toxic combustion gases having relatively small amounts of water vapor.

Abstract: A shock tube connector system comprises a substantially cylindrical detonator having a longitudinal axis a block body receiving the detonator therein, and an end cap. The detonator includes an axisymmetric exterior shell including a cylindrical main section, a cylindrical explosive end portion having a diameter less than the diameter of the main section, and a transition portion connecting the main section and the explosive end portion of the shell. An explosive charge is contained within the explosive end portion of the shell and is distributed along the longitudinal length of the explosive end portion. The explosive charge preferable comprises two portions of lead azide or a first charge portion of lead azide and PETN and a second charge portion of PETN. An initiating shock tube is operatively connected to the explosive charge via a delay element. The block body includes a housing within which the main section of the detonator is received.

Abstract: A control system for controlling the initiation of detonation of a series of explosive charges (13) spaced apart from each other in boreholes (12) formed in a rock medium (10) to be blasted, said system being operative to apply controlled time difference in the time interval between successive detonations of at least one phase of the series of charges, and which includes at least three successive detonations, so as to reduce the probability of consecutive stimulation and amplification of ground vibration by reason of the detonation of the charges in the rock medium.

Abstract: A perforating gun assembly that includes at least one component that is constructed from a composite material and that is impermeable to wellbore fluids. The components may include the outer carrier and/or loading tube of a perforating gun, the connecting tubing of a gun release mechanism, and the gun connector used to attach adjacent perforating guns. The composite material is designed to be very brittle under dynamic impact. The component is made impermeable to wellbore fluids by including an impermeable liner therein. The impermeable liner can be bonded to the inner or outer surface of the component or can be embedded within the component. Since it is brittle under dynamic impact, the composite component shatters into small pieces upon detonation of the perforating gun.

Abstract: A line charge assembly and system are provided for use in a shallow-water obstruction clearing operation. Each assembly has a propulsion unit capable of flight through the air, a line charge array, an air-safed water-armed fuze, and at least one explosive diode. The line charge array is defined by a plurality of line charges successively coupled to one another by a line capable of transferring detonation energy therealong successively to each of the line charges. One end of the line charge array is coupled to the propulsion unit and the other end is coupled to the fuze. The fuze is capable of generating the detonation energy only when in water. The explosive diode is positioned in the line charge array to limit transfer of the detonation energy in a direction of propagation running from the fuze to the propulsion unit. The system utilizes a plurality of the line charge assemblies deployed over an area.

Abstract: A line charge assembly and system are provided for use in a shallow-water obstruction clearing operation. Each assembly has a propulsion unit capable of flight through the air, a line charge array, an air-safed water-armed fuze, a first interrupter disposed between the line charge array and the fuze, and a second interrupter disposed in the line charge array. The line charge array is defined by a plurality of line charges successively coupled to one another by a detonation line capable of transferring detonation energy therealong successively to each line charge. The line charge array has a first end coupled to the propulsion unit and has a second end coupled to the first interrupter. The fuze generates the detonation energy at the expiration of a first time period provided the fuse is in water. The first interrupter permits the detonation energy to be transferred from the fuze to the second end of the line charge array until the expiration of a second time period.

Abstract: The present invention relates to a method for avoiding uneven ignition when initiating artillery propellant powder charges (1) which comprise a plurality of partial charges of the so-called modular type and which are initiated by means of laser initiation systems or conventional ignition cartridges. The invention also includes artillery propellant powder charge modules designed in accordance with this method. The invention is also based on the fact that each such charge module or modular charge has on the one hand been provided with an initiating charge (18, 19) at each end of the central ignition channel (11), where this initiating charge can consist for example of black powder, and, on the other hand, the middle part of the same ignition channel has been provided with a specially designed firing unit (14) consisting of a number of ring elements between which narrow ignition gaps (17) are maintained.

Abstract: Disclosed is an aerosol generating device comprising a cartridge containing a propellant. When ignited, propellant gases expand through a diffuser, then through and into a clearing pad and then through and into a filler area, thereby de-agglomerating and fluidizing the filler and increasing pressure until a frangible end seal on the retainer end of the cartridge ruptures and releases the filler as an aerosol cloud. Methods for disseminating an aerosol and for using the device are also disclosed.

Abstract: A method and apparatus for use in a wellbore includes explosive components, a housing containing the explosive components, and at least one protection barrier mounted on the housing to reduce transmissibility of an external force load to the housing. The explosive components array include shaped charges and detonating cords for use in perforating guns.

Abstract: System for clearing both light and heavy obstacles, in which one or more flying metal plates are propelled against heavy obstacles by explosive forces which also expand a folded continous rod member into a curvilinear, generally annular configuration that cuts through light obstacles such as concertina wire in the process of unfolding.

Abstract: A method for forming a breathable film material. A film which is a blend of a thermoplastic polymer and an inorganic filler is fed between a first roll and a second roll. The first roll has a plurality of toothed regions spaced apart by a plurality of grooved regions. The toothed regions include a plurality of teeth. The second roll has a plurality of teeth which mesh with the teeth on the first roll. As the film is fed between the first roll and the second roll the portion of the film passing between the grooved regions on the first roll and the teeth on the second roll remains substantially planar forming first regions in the film while the portion of the film passing between the teeth on the first roll and the teeth on the second roll are formed into second regions having raised rib-like elements.