Electrically actuated explosive device

Claim 1

AN EXPLOSIVE INITIATOR COMPRISING A CYLINDRICAL METAL SHELL OPEN AT ONE END AND INTEGRALLY CLOSED AT THE OTHER END, AT LEAST ONE EXPLOSIVE CHARGE WITHIN THE SHELL, AND AN IGNITION ASSEMBLY TIGHTLY, PERIPHERALLY ENGAGED BY AND CLOSING THE SHELL AT ITS OPEN END, SAID IGNITION ASSEMBLY BEING IN PROPAGATING RELATIONSHIP TO AND EXPLOSIVE CHARGE AND COMPRISING (A) A SUBSTANTIALLY CYLINDRICAL INSULATING PLUG COMPOSED OF A CENTRAL CYLINDER OF FLEXIBLE INSULATION MATERIAL AND A RIGID REINFORCING SHEATH IN SNUG PERIPHERAL ENGAGEMENT WITH SAID CYLINDER, (B) A SINGLE ELECTRICAL CONDUCTOR EXTENDING SUBSTANTIALLY AXIALLY THROUGH THE PLUG AND HAVING AN EXPOSED PORTION EXTENDING SUBSTANTIALLY AXIALLY FROM THE END OF SAID PLUG CLOSET TO THE CLOSED END OF THE SHELL, (C) AN ELECTRICALLY CONDUCTIVE ELEMENT OF HIGH RESISTANCE AFFIXED TO THE END OF THE EXPOSED PORTION OF THE CONDUCTOR AND HAVING A SECTION OF ITS LENGTH ENGAGED BETWEEN THE REINFORCING SHEATH AND THE SHELL, AND HOMOGENEOUSLY BONDED DIRECTLY TO SAID SHELL, AND (D) A HEAT-SENSITIVE IGNITION COMPOSITION IN INTIMATE CONTACT WITH THE ELEMENT OF HIGH RESISTANCE.