Environmetally insensitive electric detonator system and method for demolition and blasting

#1. Field of the Invention.

#The present invention relates to demolition and blasting generally, e.g., in mines quarries, construction, for example, and, more particularly, but not by way of limitation, to an environmentally insensitive electric detonator system and method for initiating demolition and blasting explosives, fuels, pyrotechnics, and similar explosive items.

#2. Background Art

#Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, submitted for purposes of illustration only and not intended to define the scope of the invention, on which:

#FIG. 1 is a fragmentary, block/schematic diagram illustrating the general arrangement of the present invention.

#FIGS. 2A and 2B together comprise a schematic diagram of safe/arm circuitry employed in the present invention.

#Reference should now be made to the drawing figures, on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen also on other views.

#FIG. 1 illustrates the general arrangement of the present invention for use in detonating a main explosive charge 10 which is shown as being embedded in a body of material 12 which comprises a portion of a building, rock, or other structure which is to be demolished or blasted. Disposed adjacent main explosive charge 10 is a fireset 14, including, in this case, an exploding foil initiator (EFI) and associated insensitive explosive 20, which receives charging current from firing and safe/arm circuitry 16. Safe/arm circuitry 16 receives a pulse input from an initiating source, such as a remote RF receiver or a conventional blasting machine (neither shown), the pulse input having, in this case, an amplitude of about 60-100 volts and a duration of about 250 seconds nominal. Elements 14 and 16 are similar to elements noted above as having been used in munitions detonating systems for at least 15-20 years.

#Fireset 14 includes an initiating charge 20 of an environmentally insensitive explosive material, such as hexanitrostilbene, adjacent which is an exploding foil initiator 22. In use, safe/arm circuitry 16 outputs a DC voltage which is received by fireset 14. This DC voltage charges a capacitor 24. When the voltage reaches a predetermined level, an overvoltage switch 26 closes, causing capacitor 24 to discharge through exploding foil initiator 22, thus detonating initiating charge 20.