Abstract: An exploding bridge wire (EBW) initiator assembly is provided which is particularly adapted for the initiation of an attached length of low energy shock wave conductor. The EBW comprises a hollow tube having an exploding bridge wire in one end of the tube, which directly initiates a length of shock wave conductor inserted into the opposite end of the tube. The entire assembly may be housed within a protective enclosure adapted for snap-fit connection with a source of electrical energy. The initiator can be initiated by relatively low voltage power supplies and is significantly safer than conventional EBW initiators.

Abstract: A system is provided for initiating a blasting cap wherein pulsating light energy is converted to electrical energy. An optical coupler couples the source of energy to a remote firing arrangement to transfer the generated pulsating light energy to the firing arrangement. An electrical connection connects the firing arrangement to an ignition resistor in a detonator. Thus, the generated light energy is converted to electrical energy and is transferred to the ignition resistor, the transferred electrical energy being the firing energy for the ignition resistor.

Abstract: A novel initiator (blasting cap) for explosives is provided. The initiator, which may be electric or non-electric, comprises a tubular metal shell having within a base charge, a delay train, a priming charge and an ignition means. Interposed between the delay train and the priming charge is an annular collar or ring of resilient material in contact with the inner wall of the metal shell. The construction results in a markedly improved resistance against shock initiation.

Abstract: A field adjustable delay connector for use in detonating cord hook-ups for multi-charge blasting particularly adapted to work effectively with low energy shock or detonating cord. The delay connector is so constructed that the donor cord initiates combustion in a variable length of burning composition the length being mechanically adjustable by the blaster during hook-up.

Abstract: Low energy explosive shock tubing is provided which consists of a two-ply, inner and outer layer plastic tube having a plurality of lengthwise textile filaments bonded into the interface between the plastic layers. The textile filaments are chosen for their low elongation properties and the resultant shock tube resists stretching especially in warm borehole environments.

Abstract: An improved pyrotechnic delay composition of intermediate to slow burning time is provided for use in both electric and non-electric blasting caps. The composition comprises a mixture of barium sulphate and silicon to which may optionally be added a proportion of red lead oxide. The composition is characterized by the basence of any carcinogenic properties and is not water soluble.

Abstract: A non-electric delay blasting method is provided which comprises the use of single trunk line of detonating cord having a series of detonating relays, all of the same delay period, connected at spaced intervals along its length. Branch lines of detonating cord are connected in groups to the trunk line in the intervals between the relays and each branch line has a delay detonator of the same delay period attached thereto. The delay period of the relays is shorter than that of the delay detonators. The detonators within the groups detonate in a random manner. The method eliminates the need to use large numbers of different delay period detonators in a multi-charge blast thus simplifying preparation of the charge and reducing inventories.

Abstract: A very-high-detonation-velocity detonating cord of the type having axial hollow space within the core is modified in its velocity of detonation by inserting at selected locations within the hollow core, elongated, flexible blockage elements. By a selection of the number of such blockage elements, the VOD of the cord may be controlled within narrow limits. Detonating cord having specific or controlled VOD has particular application in explosives welding and metal working.

Abstract: A novel pyrotechnic delay composition is provided for use in both non-electric and electric blasting caps which is characterized by uniform burn rate and low toxicity. The composition, comprising an admixture of stannic oxide and silicon, has no carcinogenic properties.

Abstract: An improved cord-like detonating device is provided for use in non-electric blasting methods. The device comprises a substantially standard detonating cord length wherein a central longitudinal core of the cord consists of a hollow, low energy shock wave conductor. The device has particular utility in long hole blasting with toe priming. Initiating energy can be transmitted down the hole to the toe primer charge through the low energy shock wave conductor. The detonating primer initiates the outer detonating cord sheath which transmits energy to set off additional primer charges attached thereto.