The Ensign-bickford Company

Robert G Pallanck

Kenneth A Rode

Ernest L Gladden

Ronald M Dufrane

Richard J Michna

Dorman, Mark D

An initiation signal transmission line tube (10a, 10b, 10', etc.), which is effective to transmit an initiation signal therethrough, contains one or more rupture lines (20a, 20b and 20c, etc.) in the tube wall. Rupture lines (20a, 20b and 20c, etc.), which may be weld seams or grooves or both, are ruptured by the initiation signal passing therethrough. The spent tube carcass is split or fragmented and therefore less troublesome as litter on a work site than an intact shock tube carcass. If the tube is extruded, a rupture line may be formed by contacting the parison (118) from which the tube is made with scoring means, e.g., a pin or blade (124a, 124b). Optionally, the scoring means may be moved radially during the extrusion process, to form serpentine, e.g., helical, rupture lines. Preferably, the rupture lines intersect periodically and, upon firing, the tube is fragmented into shards. Alternatively, the tube (50d) may be extruded in segments (62) that adhere to each other at interfaces (64) which provide rupture lines for the tube. Optionally, some segments (62) may be formed from different extrudate materials than others.

Fissile shock tube and method of making the same

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.

Extended range digital delay detonator

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.

Impulse signal delay unit

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.

Digital delay detonator

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.

Growing community of inventors

Windsor, CT, United States of America

Robert G Pallanck