Blasting cap assembly

Claim 1

A BLASTING CAP ASSEMBLY WHICH COMPRISES A PLASTIC SHELL CLOSED AT ONE END AND FORMED FROM A SOLID POLYMER SELECTED FROM THE GROUP CONSISTING OF A LINEAR POLYETHYLENE CHARACTERIZED BY A SOFTENING POINT OF AT LEAST 125* C. AND A REDUCED SPECIFIC VISCOSITY WITHIN THE RANGE OF 2.0 TO 4.0, A CRYSTALLINE POLYPROPYLENE CHARACTERIZED BY A SOFTENING POINT OF AT LEAST 160* C. AND A REDUCED SPECIFIC VISCOSITY WITHIN THE RANGE OF 2 TO 10, AND AN ALLOY CONSISTING OF SAID POLYETHYLENE AND SAID POLYPROPYLENE, A PLASTIC PLUG FORMED SOLELY FROM THE ABOVE DEFINED SOLID POLYMER AND DISPOSED WITHIN SAID SHELL IN COMPLETE CLOSING RELATIONSHIP THEREWITH, AND HEAT SEALED WITH SAID SHELL IN FUSED WATERTIGHT RELATIONSHIP THEREWITH AT THE PLUGSHELL INTERFACE, A PAIR OF ELECTRICAL CONDUCTOR WIRES EXTENDING SEPARATELY, INTO SAID SHELL FROM POINTS EXTERNAL THERETO THROUGH THE END THEREOF OPPOSITE SAID CLOSED END AND THROUGH SAID PLUG, AND TERMINATING IN SAID SHELL INTERMEDIATE SAID PLUG AND THE ABOVE SAID CLOSED SHELL END, MEANS FOR ELECTRICALLY INSULATING SAID CONDUCTOR WIRES, SAID PLUG BEING SEALED IN WATERTIGHT RELATIONSHIP WITH A SECTION OF EACH OF SAID CONDUCTOR WIRES EXTENDING THERETHROUGH, A RESISTANCE WIRE WITHIN SAID SHELL INTERMEDIATE SAID PLUG AND THE SAID CLOSED SHELL END AND CONNECTING THE SAID CONDUCTOR WIRES, AND A HEAT SENSITIVE EXPLOSIVE INITIATABLE BY HEAT DEVELOPED BY PASSAGE OF ELECTRIC CURRENT THROUGH SAID RESISTANCE WIRE, AND DISPOSED WITHIN SAID SHELL INTERMEDIATE SAID PLUG AND THE SAID CLOSED END IN OPERATIVE RELATIONSHIP WITH SAID RESISTANCE WIRE SO AS TO BE SO INITIATED BY PASSAGE OF ELECTRIC CURRENT VIA SAID CONDUCTORS THROUGH SAID RESISTANCE WIRE.