Abstract: A method of stemming a blast hole loaded with an explosive charge. The blast hole has side walls, an outwardly opening mouth and a central axis extending longitudinally of the blast hole. The method comprises inserting a conduit having a discharge end inwardly through the mouth of the blast hole and positioning the discharge end of the conduit within the blast hole generally adjacent the explosive charge. Particulate stemming material is forced under pressure through the conduit for exit from its discharge end into the blast hole toward the explosive charge thereby to pack stemming material in the blast hole adjacent the explosive charge. As stemming material is forced out the discharge end of the conduit, the discharge end of the conduit is moved generally axially outwardly relative to the blast hole toward the mouth of the blast hole to simultaneously fill and pack the blast hole with stemming material.

Abstract: A plug for use in stemming a blast hole having an explosive charge therein. The plug comprises a wedge member and a stabilizing structure on the wedge member. The wedge member tapers in an outward direction from a relatively wide base to a relatively narrow end and has a central axis extending endwise with respect to the wedge member. The stabilizing structure extends generally axially with respect to the wedge member from adjacent the base of the wedge member. The plug is to be positioned in the blast hole with the base of the wedge member facing inwardly toward the explosive charge, with the narrow end of the wedge member facing outwardly toward the mouth of the blast hole, with the central axis of the wedge member generally coincident with the central longitudinal axis of the blast hole, and with the stabilizing structure in close proximity to the side walls of the blast hole.

Abstract: This invention relates to a waterproof device for holding explosives in a borehole, a method of lining at least a portion of a borehole with an elongated, flexible, waterproof liner and a method of lining at least a portion a borehole with an elongated, flexible, waterproof liner and filling the liner with explosives.

Abstract: An explosive stemming device for dispensing granular material into a boree containing an explosive charge therein is disclosed as including a cylindrical member having a flexible sleeve-like liner adapted to conform to the interior thereof when filled with granular material. One end of the liner is turned around an end of the cylindrical member and secured thereto while the other end of the liner is fixed to a centrally positioned pipe whereby extracting of the member containing granular material from the borehole causes everting or turning inside out of the liner and dispensing of the material in the borehole.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of exposives into a borehole in order to produce desired blast results acording to the several methods of the invention.

Abstract: Inflatable devices configured for supporting explosives particularly in vertical boreholes of widely varying diameter. The inflatable devices of the invention can be used in the pre-splitting and blast removal of earth formations by suspending explosives in both pre-splitting and production boreholes. Plugging of such boreholes is accomplished through the use of the present inflatable devices which are formed of flexible polymeric material and which stretch to seal boreholes and to exert forces against borehole walls sufficient to support heavy columns of explosives and/or stemming at desirable borehole locations. The present inflatable devices are restrained into a pre-splitting configuration and inflated to a configuration capable of supporting explosives and/or stemming within a borehole.

Abstract: The invention provides methods and apparatus useful primarily in the presplitting and blast removal of earth formations, the improvements according to the invention involving the use of inflatable devices suspended in boreholes used in shattering earth formations. The inflatable devices of the invention can be of various shapes and are provided with valves to allow a fluid such as air to be pumped into each device on placement of the device at a desired location in a borehole. The inflatable devices are preferably formed of a flexible, polymeric material which allows a desired degree of stretching to cause plugging of a borehole. The "plug" formed by an inflatable device of the invention allows loading of explosives into a borehole in order to produce desired blast results according to the several methods of the invention.

Abstract: A blasting plug used in conjunction with a drilled blasting hole and serving fill retaining purposes in a use condition. The blasting plug is an assembly of lightweight material, and serves as a substitute for inflatable air bags now in use and, thereby, represents a considerable cost reduction. Typically, the blasting plug is defined by plywood layers having one or more sections of plastic resin disposed therebetween. The invention presents an inexpensive blasting plug which satisfies operational needs.

Abstract: An inflatable borehole plug is disclosed, the inflation of which is achieved by chemical reaction of two co-reagents disposed therein which results in evolution of a gas. The borehole plug can be dropped or lowered down a borehole to a preselected position since the extent of gas-producing chemical reaction is able to be delayed following initiation of mixing of co-reagents, by delay means in the borehole plug, for sufficient time to enable placement of the borehole plug.

Abstract: An inflatable wand for positioning within an upward oriented, mining borehole and near a lower collar opening thereof wherein the wand provides a conduit for introducing and retaining liquid explosive materials within the borehole. The wand includes a flexible tube with longitudinally oriented reinforcing fibers embedded in an elastic composition such as rubber. The tube is constructed to permit radial elongation in response to a force arising within the tube and directed radially outward, but to restrain against axial elongation during use. Such radial elongation arises because of back pressure developed by the flowing explosive as it is impeded at a valve outlet at the distal end of the wand. Enlargement of the wand seals the opening of the borehole without destruction of the elastic material on sharp points and edges of the borehole collar.

Abstract: An expansive demolition agent prepared by crushing a clinker for manufacturing powdered expansive demolition agent obtained by sintering, which is capable of hydrating and expanding in a hole drilled in a brittle material to demolish the brittle material, the maximum particle diameter of the agent being one-third or less the diameter of the hole, and containing 10% or less of fine particles having a particle diameter of 0.3 mm or less.

Abstract: A composition for making an in situ disposable propellant canister for utilization in controlled pulse fracturing. Said canister is composed of a porous light fabric material in combination with a gel solution. The gel creates a formable mass after solidification. Said mass can be made of a gel thickness sufficient to support and contain a propellant. Upon ignition of said propellant, the gelled canister is destroyed thereby alleviating a clean up operation.

Abstract: A stemming construction for a blast hole loaded with an explosive charge, comprising a tapering wedge member dispersed in the blast hole outwardly of the explosive charge with its narrower end facing outwardly toward the mouth of the blast hole, and particulate stemming material in the blast hole outwardly of the wedge member. Detonation of the explosive drives the wedge member into the stemming material to wedge the stemming material against the walls of the blast hole. The wedge member is preferably cone-shaped and can be provided with a stabilizing rod to prevent it from tilting.

Abstract: A spall shield for armor plate for restraining at least a portion of flying fragments resulting from impact of a projectile with said armor plate, comprises a plasticized resin of the type commonly used as an interlayer of safety plate glass such as for example, plasticized polyvinyl acetal resin or plasticized polyvinyl butyral resin. The novel spall shield replaces nylon cloth, rubber, felt or resin impregnated glass fabric of the prior art while being at least as thin and light as the adhesive commonly used to adhere such prior art spall shield materials to the armor plate. The spall shield of the present invention is substantially lower in weight and substantially more efficient in performance than conventional spall shields.

Abstract: Shallow boreholes, e.g. seismic shot holes are usually sealed with cement, gravel or more recently by pouring a water swellable material such as bentonite into the hole. A more effective method of sealing involves the insertion of an impermeable bottom plug into the hole, followed by a thick layer of a particulate material such as sodium bentonite which expands when in contact with water to seal the hole. A top plug can also be used with or without a cover of cuttings to promote lateral expansion of the sealant in the hole.

Abstract: An explosive powder charge operated tool for driving fastening elements into a receiving material has a locking member supported in the housing for effecting the return movement of the driving member located within the barrel. The locking member has a radially inwardly directed nose located in the path of an annular shoulder on the driving member. A retaining member with a support shoulder holds the locking member in position within the housing. The retaining member and shoulder are rotatable about the housing for aligning an aperture in the shoulder with the locking member so that the locking member can be removed without the use of any auxiliary tools.

Abstract: A shaped charge carrier assembly apparatus includes a carrier having a plurality of carrier segments integrally formed from a single substantially flat elongated sheet of structural material. An interconnecting portion is located between each two adjacent segments and is integrally connected therewith. The interconnecting portion provides a rigid and precise angular offset between adjacent segments through a permanent deformation of the interconnecting portion. Each carrier segment has a charge receiving opening therein and includes a pair of diametrically opposed wedges for snugly enaging a pair of elastomeric lugs of a shaped charge.

Abstract: There is provided a new and useful tamping and topping plug for use in a seismic bore hole, and comprising a cylindrical body member having a forward and a rearward end and terminating at its forward end with a closed end part, a plurality of elongated members extending outwardly and rearwardly from at least one end and preferably from the forward and rearward ends of the body member, the members so arranged as to give the plug axial stability when inserted into a bore hole. There is also provided a process utilizing the plug for enhancing information available from seismic blasting.

Abstract: An inflatable hour glass shaped rubber plug is placed in blasting holes immediately after they are drilled. This plug prevents unwanted debris from entering drilled holes, during idle periods. Thus it will allow necessary space for blasting agents, resulting in a greater shattered blast, and level roadbed conditions. As a direct result, it will increase production in loading and haulage equipment, and lower maintenance cost and mining operation cost overall.

Abstract: An explosive activated assembly for repairing a heat exchange tube in which a grooved metal casing is inserted into the tube to be repaired and has a plurality of projections extending from the outer surface thereof. A force-transmitting member extends within a bore formed in the casing and contains an explosive member so that, upon detonation of the explosive member, the force-transmitting member and the casing are expanded radially outwardly to drive the projections against the tube. A booster is located within the casing and adjacent the charge and is activated by a transfer cord connected to an externally located detonator. The casing is formed with an extension that extends over a portion of the transfer cord and has a hole through which the cord extends to contain the debris and vapor caused by the explosion.

Abstract: To prevent the rapid escape of high-pressure explosion gases when an explosive charge is initiated in a borehole, the hole is stemmed with chunks of readily liquefiable and/or vaporizable solid material, preferably chunks of ice and/or chunks of dry ice, piled up one upon the other so as to form a columnar bed of pre-solidified stemming material. The column remains in place during the explosion, and thereafter disappears by melting and/or subliming on absorbing heat from the surrounding formation. A preferred stemming column comprises a combination of ice chunks and chunks of dry ice, e.g., wherein the ratio of dry ice to ice in the column decreases with distance from the explosive charge.

Abstract: A method and apparatus for delivering an explosive to the bottom of a borehole containing water without allowing a detrimental amount of mixing between the explosive and the water. More particularly, the present invention allows an ammonium nitrate rich bulk explosive to be placed in a borehole without allowing the explosive composition to change significantly through dissolution of its constituents. The apparatus of the present invention includes a length of collapsible tubing having a plurality of apertures near its base and a weight attached to its base. The tubing is then lowered into a borehole. The weight causes the tubing to extend through any water layer within the borehole and the collapsible nature of the tubing serves to keep any significant amount of water from entering the tube. An explosive can then be flowed into the mouth of the tubing and down through the length of the tubing to the bottom of the borehole.

Abstract: A pre-packaged explosive charge of the type made up of modules having a threaded male coupling end and a threaded female coupling end is loaded into a bore hole by use of a plug fitting threadably attachable to the uppermost charge module. The fitting is constructed so that the torque required for disconnection of the fitting from the module is substantially less than the torque required to separate one module from another.

Abstract: An explosive or stemming package is provided which is self-retaining in vertical or inclined up-holes in stable rock. The package containing a flowable material, for example, slurry explosives, consists of a thin-walled cylindrical bag having at least one longitudinal, external pleat held closed by means of an adhered overcovering or tape. With the package held in position in the up-hole by a push rod, the tape is severed by means of a rip cord allowing the pleat to open. The slumping contents press the package closely against the borehole wall for secure retention without additional support. Improved coupling of the explosive charge to the rock is also provided giving enhanced blasting efficiency.

Abstract: Cartridge for bulling mine holes, which is of cylindrical shape, is made of n elastic material and possesses a zone 7 capable of deforming axially and a zone 6 capable of deforming radially, under the effect of an axial or radial pressure exerted on the cartridge or under the effect of an internal pressure variation, in which cartridge the volume of the zone 7 capable of deforming axially is greater than the volume of the zone 6 capable of deforming radially.

Abstract: An improved process is provided for blasting in situ oil shale retorts, and oil and gas wells. In the process, a specially formed concrete plug is installed at a desired depth in a bottomless blast hole and an explosive charge is placed upon the plug and detonated to blast the underground formation. The plug is accurately and reliably set by lowering a canister, which releasably houses a bag support assembly supporting a bag of concrete slurry, to a desired depth into the blast hole. The bag support assembly and bag of wet concrete are subsequently dropped a fixed distance below the canister. The bag of concrete expands, dries, and hardens against the walls of the blast hole to form a permanent stationary plug across the blast hole. In the preferred process, the bag support assembly is formed by casting a concrete disc around a drainpipe, and the bag support assembly is lowered and released from the canister with the aid of an electrically powered sequencer.

Abstract: A plugging apparatus is provided to reliably plug a bottomless blast hole in underground oil shale retorts and oil and gas wells. The plugging apparatus has a special electrically powered sequencer which automatically lowers and releases a bag of cementatious slurry, supported by a drainpipe-reinforced concrete disc, from a canister to form a composite blasting plug in the blast hole.

Abstract: A device for breaking monolithic structures or pulsating by inducing pressure in a liquid filling a pre-drilled hole in the monolithic structure to be shattered comprises a tubular housing having a cavity for accommodating an explosive charge. Provided in the lower portion of the housing is a partition of an elastomeric material and a pipe serving to locate the device in a mouth of the hole and be filled with the liquid so as to form an air gap between the partition and the surface of the liquid. In order to retain the device inside the hole a means is provided connected to the housing and fashioned as an inertia element disposed outside the hole.

Abstract: A tapping apparatus and method for making connections to pipelines and vessels while they are in service and contain fluid under pressure. The tapping apparatus and method includes an explosively driven punch that is operated to penetrate the pipeline. A tensile force is applied to retract the punch, and allow the fluid to pass from the pipeline through the apparatus and into the service connection.

Abstract: An explosive plug for blocking tubes comprises a tubular metal body closed at one end by a solid head and having at the other end a surface-contact region containing at least two spaced apart charges actuable by a detonator. The metal body when placed in a tube to be blocked is so arranged that the surface-contact region is coaxial with but at a distance from the tube so that successive explosion of the charges causes the surface-contact region to be radially spattered against the interior of the tube thus producing a reliable metal weld or welds extending along a substantial part of the end region of the tube.

Abstract: A rock breaker comprising a tool insertable in a hole in a rock and fed through a supply line with an incompressible liquid to maintain a column of the liquid in the hole, and means to apply to the liquid a shock means sufficiently high to fracture the rock, the tool comprising a hollow stem having an expansible collet and a resilient sealing ring and mechanical means to expand the collet and ring.