Explosive charge

Claim 1

A LINEAR EXPLOSIVE CHARGE ELEMENT ADAPTED TO BE FASTENED IN LINEAR COMBINATION WITH AT LEAST ONE OR MORE SIMILAR ELEMENTS TO FORM AN EXPLOSIVE CHARGE ASSEMBLY FOR DETONATION BELOW THE SURFACE OF THE EARTH, EACH CHARGE ELEMENT BEING OF SUCH A LENGTH AS TO BE EASILY HANDLED AT A SHOT POINT, AND EACH ELEMENT ADAPTED TO BE CONSTRUCTED FOR A PREDETERMINED AVERAGE VELOCITY OF PROPAGATION OF DETONATION ALONG THE AXIS OF THE ELEMENT WHICH IS SUBSTANTIALLY MATCHED TO THE VELOCITY OF ELASTIC WAVE PROPAGATION IN THE EARTH MATERIAL ADJACENT THE EXPLOSIVE ELEMENT, COMPRISING, (1) A LINEAR SUBSTANTIALLY RIGID CYLINDRICAL SUPPORT MEMBER, (2) MEANS FORMING A PATTERN OF HELICAL GUIDES AT THE SURFACE OF SAID SUPPORT MEMBER ADAPTED TO GUIDE THE PLACEMENT OF A LENGTH OF CORDLIKE EXPLOSIVE ELEMENT, (3) SAID GUIDES OCCUPYING SUBSTANTIALLY THE ENTIRE LENGTH OF SAID SUPPORT MEMBER, (4) SAID PATTERN OF GUIDES COMPRISING AT LEAST TWO SEGMENTS, EACH SEGMENT HAVING A DIFFERENT HELICAL ANGLE FROM THE OTHER SEGMENT, (5) CORDLIKE EXPLOSIVE COMPOSITION PLACED IN SAID HELICAL GUIDES AND EXTENDING FROM END TO END OF SAID MEMBER, THE COMPOSITION IN THE HELIX OF GREATEST ANGLE BEING LARGER IN CHARGE WEIGHT PER UNIT LENGTH THAN THE COMPOSITION IN THE HELIX OF SMALLEST ANGLE, (6) THE HELICAL ANGLE OF SAID GUIDES HAVING THE LARGER WEIGHT PER UNIT LENGTH OF COMPOSITION IN ONE SEG-