Abstract: An electronic safe/arm device is powered internally by a low-voltage, periodic power source that has insufficient voltage by itself to fire the detonator. The circuit therefore includes a step-up transformer from which sufficient voltage to fire the detonator is obtained. The step-up transformer charges an arming circuit which stores high-voltage power to fire the detonator and also powers the firing circuit which discharges the stored high-voltage energy through the detonator at the appropriate time, to fire the device. The low-voltage, periodic power source may include a low-voltage battery and a dynamic switch for providing periodic pulses of low-voltage energy to the primary winding of the transformer, and the dynamic switch may be powered from the output of the transformer, so that the low-voltage battery has insufficient voltage to power the dynamic switch.

Abstract: An extended delay detonator (blasting cap) provides a preselected, electronically controlled delay between an incoming non-electric impulse input signal from, e.g., a shock tube or other input transmission line, and detonation of the output charge of the detonator. The delay detonator has a housing closed at one end and open at the other end for coupling to the input transmission line, the signal from which may be amplified by a booster charge mounted within the housing. A piezoelectric generator converts the optionally amplified impulse input signal to electrical output energy. A battery-powered programmable electric delay circuit is activated by the electrical output from the transducer, counts the preselected delay period, and at the end thereof ignites an electrically operable output charge. A method for interposing a preselected delay between the application of a non-electric impulse input signal and the detonation of the output charge is also provided.

Abstract: A coupling device (10) for coupling a detonator cap (20) with an unfixtured detonating cord (80, FIG. 3 ) after removing a shipping plug (41, FIG. 2 ), features a sleeve member (12) having a longitudinal sleeve bore (18) extending therethrough for receiving a detonator cap (20) therein. The detonator cap (20) extends to the transition end (22) of the sleeve member (12) so that the detonating cord (80) does not enter the sleeve bore (18). A nut member (14) has an aperture (24) for receiving the cord (80) and is secured to the sleeve member (12) with its aperture (24) aligned with the bore (18). A ferrule (16) is seated on the sleeve member (12) and grips the detonating cord (80) when the nut member (14) is secured onto the sleeve member (12).

Abstract: A signal transmission tube assembly includes a signal transmission tube, such as a coil of shock tube on a spool, having opposite terminal ends and containing a reactive material. The open terminal ends of the shock tube provide the sole exits for the signal generated therein and the sole entry points for contaminants. Sealing means seal both terminal ends of the signal transmission tube against escape from the assembly of the signal engendered by initiated reaction of the reactive material, and protects the interior of the signal transmission tube from contamination. The sealing means may be a releasable sealing means which can be actuated to release the transmission tube from it, thereby facilitating re-use of the sealing means. Further, the sealing means may comprise a surge chamber to relieve pressure engendered by reaction of the reactive material and thereby militate against rupture of the signal transmission tube and consequent release from the assembly of a signal.

Abstract: A low-energy blasting initiation system, method and surface connection is disclosed for low-noise, time controlled transmission of an initiation signal from a signal initiation source to a plurality of remote blasting elements. A connector block of the system comprises a housing having a channel formed therein for receiving a low energy detonator. A tube engaging member is formed on an end of the housing for holding transmission tubes adjacent an end of the channel. Tabs are formed in the channel for snap-fit retention of the detonator, and positioning cleats are formed in the channel for positioning of the detonator with an explosive end of the detonator in juxtaposed energy communicating relationship with a side of the transmission tubes. Non-direction signal transmission is initiated in the transmission tubes in response to activation of the detonator for time-controlled transmission of the initiation signal to the remote blasting system elements.

Abstract: A separation device (23a-23d) comprises a frangible joint (24a-24d) comprising joinder flanges (27a, 27b) interconnected by walls (126a, 126b, 226a, 226b, 326a, 326b, 426a, 426b) having fracture grooves (28a, 28b) and defining a channel (36a-36c) therein. Within the channel (36a-36c) is disposed an expansion member (10, 10a, 10b) containing a detonation charge (16) and having expansion regions (34a-34c, 134a, 134b) that expand upon detonation of the charge (16). The expansion region bears against walls at the junctions (32a, 32b, 32b', 132a, 132b, 232a, 232b) thereof with joinder flanges (27a, 27b) to provide separation thrust as well as causing frangible joint (24a-24d) to fracture at fracture grooves (28a, 28b).

Abstract: A digital delay unit for use in blasting operations and the like provides a selected delay between an input impulse signal and an output impulse signal. The delay unit may have a fixed, preset electronically controlled delay period or, optionally, is programmable to enable user-selected changes in an electronically controlled delay lay period. The delay unit has a housing which serves to connect the input and output transmission lines and house the other components, which includes a piezoelectric transducer which converts the input impulse energy, or the energy released by detonation of a booster charge by the input impulse energy, to electrical energy which is used to generate a first electric signal and a second electric signal. An electronic circuit is responsive to the first electric signal to start counting a preprogrammed delay period, after which a second electric signal is emitted to detonate an output charge which ignites one or more output transmission lines, e.g., shock tubes.

Abstract: An initiation fixture (16) for an impulse transmission tube comprises a sleeve (30) having an internal longitudinal bore. The sleeve (30) is dimensioned and configured to receive a shock tube (10) in one end and a primer cap (28) in the other. An internal fence (32) establishes a touch hole (33) between the primer cap (28) and the end of the shock tube (10). In addition, primer cap (28) and the end of shock tube (10) are separated by an intervening isolation member (34) which disperses static electricity from shock tube (10) to prevent discharge across touch hole (33) to primer cap (28). A retainer means (40) is movably disposed on an exterior surface of sleeve (30) and is dimensioned and configured to engage a triggering device (18). A first stop means (42) allows retainer (40) to secure the end of sleeve (30) within the triggering device (18) and positions primer cap (28) for detonation by a striking pin (20).

Abstract: A detonation manifold (30) for use with a separation device comprising an expansion member (10) disposed in a frangible joint (24), the expansion member comprising a flattened containment tube (20) having in cross section an oblong configuration having a major axis and a minor axis and having therein a detonation fuse (16). The manifold comprises a body portion (31) having at least one initiation port (32) for receiving an initiator device and at least one coupling flange (38) mounted on the body portion for engaging the expansion member and having a flange bore (40) for receiving the detonation fuse (16), the flange bore (40) being in detonation communication with the initiation port (32). The coupling flange (38) has in cross section an oblong configuration having a major axis and a minor axis and is dimensioned and configured so that the containment tube (20) can be flared for receiving the flange without significantly deforming the oblong configuration of the containment tube (20).

Abstract: A coupling device (10) for coupling a detonator cap (22a, 22b) with a detonating cord (82) features a sleeve member (12) having a longitudinal bore (18) extending therethrough for receiving a detonator cap (22a, 22b) in one end and a detonating cord (82) in the other. The coupling device (10) includes a nut member (14) having an aperture for receiving the cord (82) and having a compression surface (34) for bearing against a compression portion defined below when the nut member (14) is secured onto the sleeve member (12). The nut member (14) may be secured to the sleeve member (12) with its aperture aligned with the bore (18). A compression portion (31) associated with the sleeve member (12) responds to pressure from the compression surface (34) of the nut member (14) for gripping a cord (82) when the nut member (14) is secured onto the sleeve member ( 12). Thus, a cord can be securely disposed in detonation signal transmission relation to a cap without having special coupling hardware, e.g.

Abstract: An igniter (18) provides rapid longitudinal and radial propagation of the ignition reaction. The igniter may comprise a pyrotechnic material and an inorganic binder, such as silica, carried on a carrier web (10) which may be fiber-glass. One or more layers of coated web (10) are disposed to provide an igniter (18) of cylindrical configuration and having a hollow core. The coated layers are permeable to the ignition reaction to facilitate radial propagation of ignition. The hollow core and the continuous nature of the pyrotechnic layers promotes longitudinal propagation of ignition. The igniter may consist mostly or entirely of inorganic materials to reduce or eliminate the formation of carbon monoxide upon ignition, and may be contained within a radially perforated sheath (20) to form a radial ignition device (25).

Abstract: An elongated connector block for mounting a blasting cap and detonating cord in side-by-side association for side initiation, the body having a generally U-shaped transverse cross-section with a slot extending the full length thereof, the opposed sides of said slot being contoured to receive the detonating cord and the body providing an enlarged, elongated cavity for receiving the blasting cap, there being an upward integral extension of at least one side of the body forming a pinch cleat for securing a flexible detonating cord in position by winding it about the pinch cleat, the space between the one pinch cleat extension and the body being provided with a flexible retainer clip extending from the body toward the pinch cleat underside, the leg of the clip having a rest position substantially closing the space between the body and the pinch cleat to retain the free end of the detonating cord after winding about the cleat.

Abstract: An electrical delay detonator for blasting initiation systems and the like energized solely by a force input from a non-electric signal communication system, which detonator has a hollow, electrically conductive housing enclosing a booster charge connected to the source of non-electric input force, a transducer positioned in force communicating relationship with the booster charge for converting the output force from the booster charge to an electrical output signal, an electrical circuit connected to the output of the transducer for introducing a time delay in the electrical output from the transducer and an electrically operable igniter element.

Abstract: A low-energy blasting initiation system, method and surface connection is disclosed for low-noise, time controlled transmission of an initiation signal from a signal initiation source to a plurality of remote blasting elements. A connector block of the system comprises a housing having a channel formed therein for receiving a low energy detonator. A tube engaging member is formed on an end of the housing for holding transmission tubes adjacent an end of the channel. Tabs are formed in the channel for snap-fit retention of the detonator, and positioning cleats are formed in the channel for positioning of the detonator with an explosive end of the detonator in juxtaposed energy communicating relationship with a side of the transmission tubes. Non-directional signal transmission is initiated in the transmission tubes in response to activation of the detonator for time-controlled transmission of the initiation signal to the remote blasting system elements.

Abstract: The present invention combines the advantages of a prior art figure of 8 winding pattern with the traditional circular or oval pattern for packaging flexible cord to form what can be called a "figure of 80 pattern" which includes a generally S-shaped partial cord layer with the end of the S joining with a J-shaped portion arranged so that the straight portion of the J forms a continuation of the S and the curved portion of the J overlies the beginning of the S-shaped portion. This basic combination of S and J shapes designates only partial layers, the pattern can be repeated, that basic pattern can be connected to a plurality of oval turn layers or even a plurality of figure 8 turn layers as the user may elect. It is also possible to continue to merely alternate the basic layer form to provide a package having a high packaging density while permitting easy accommodation of fittings which are secured to the end of the cord.

Abstract: A delay train ignition buffer (45) is positioned between a transmission tube (11) and a delay train (25) in a detonator housing (15) or a signal transmission tube housing. The buffer controls the rate at which the transmission tube temperature/pressure pulse is applied to the delay train pyrotechnic surface, attenuating the effects of the pulse with a resulting improvement in delay timing precision. The buffer also attenuates the effects of sudden depressurization within the detonator resulting from the rupture of the transmission tube or ejection of the tube from the housing, thereby preventing separation of the reacting pyrotechnic which could otherwise cause the reaction to cease at the point of separation, thus causing failure of the delay train to continue combustion of the pyrotechnic through its length.

Abstract: A transmission tube initiator comprises a body having a passageway formed therein for receiving and retaining an initiator charge. A holder holds a side of a transmission tube in close proximity to the charge. The charge provides an initiation signal which penetrates the transmission tube and initiates a reactive substance contained in the transmission tube.

Abstract: A connection between the ends of two discrete signal transmission devices allows signal propagation between the ends of the devices. The ends of the devices are axially aligned at a close distance from one another within an alignment sleeve. A length of heat-shrink tubing having a sealant on its inner surfaces is placed over the alignment sleeve and the ends of the devices. The tubing is heated and provides axially compressive and radially compressive forces on the alignment sleeve and device ends thereby providing a high tensile strength connection between the device ends.

Abstract: A plurality of discrete transmission tubes are held in axially extending juxtaposed relation by an outer sheath which coextensively covers the tubes. An axially extending line of weakness is formed along the length of the sheath. The transmission tubes may be simultaneously initiated for redundent transmission of an initiation signal.

Abstract: Blasting signal transmission tube comprising a length of elongated flexible hollow tube and a self-oxidizing combustible substance disposed within the tube for transmitting a blasting signal along the interior of the tube length, the hollow tube having a varying interior axial cross-sectional area at longitudinally spaced intervals along the tube length for reducing and controlling the velocity of the blasting signal. Also, a process for producing signal transmission tube comprising forming a length of elongated flexible hollow tube of predetermined interior cross section area; depositing a self-oxidizing combustible substance within the tube for transmitting a blasting signal along the interior of the tube length without destroying the tube; and introducing a plurality of discrete restrictions reducing the predetermined hollow tube interior cross-sectional area at longitudinally spaced intervals along the tube length for reducing and controlling the velocity of the blasting signal.