Explosive apparatus

Claim 1

AN EXPLOSIVE APPARATUS ESPECIALLY ADAPTED TO BE EMPLOYED WITH A DRILL BIT IN DRILLING A WELL WHICH COMPRISES, IN COMBINATION, A CASING ADAPTED TO BE INSERTED COAXIALLY IN SAID BIT AND HAVING ONE END AT LEAST PARTIALLY OPEN, AN EXPLOSIVE CHARGE HAVING A CAVITY THEREIN DISPOSED IN SAID CASING SO THAT SAID CAVITY FACES SAID OPEN END OF SAID CASING, A COMPRESSIBLE INSULATING MATERIAL DISPOSED WITHIN SAID CASING AROUND SAID EXPLOSIVE CHARGE SO THAT ALL ITS SURFACE EXCEPT SAID CAVITY IS CONTACTED BY SAID INSULATING MATERIAL, A LINER DISPOSED IN SAID CAVITY OF SAID EXPLOSIVE CHARGE, A DETONATING MEANS FOR SAID CHARGE, A SPRING ATTACHED AT ONE END TO SAID CASING AND THE OTHER END TO A LATCHING MEANS ADAPTED TO COACT WITH AND BE HELD IN A FIXED POSITION BY SAID BIT, A SWITCH HAVING A FIRST CONTACT POINT ATTACHED TO SAID LATCHING MEANS, A SECOND CONTACT POINT FLEXIBLY ATTACHED TO SAID DETONATOR SO THAT COMPRESSION OF SAID SPRING WILL CAUSE SAID FIRST AND SECOND CONTACT POINTS TO CONTACT AND THEREBY DETONATE SAID CHARGE.