Sprengpatrone

818,177. Blasting cartridge assemblies. MAGER, H. March 2, 1956 [March 8, 1955; May 25, 1955; Dec. 12, 1955], No. 6709/56. Class 9(1) A cartridge which can be connected to similar cartridges to form an explosive column as used in seismic prospecting comprises a sheath 1 of sheet metal such as Al, Cu or Zn or their alloys and having such a thickness that the sheath takes part in the explosion of the charge 2, which may have as a base inorganic nitrates Near its base, the sheath 1 has a peripheral groove 4 which engages a rib 10 of the dished cover 7 closing the flared mouth 6 of an adjacent cartridge. Above the groove 4 is a rib 5 which limits the entry of the sheath 1 into the cover 7 of the juxtaposed cartridge. The cover of the uppermost cartridge of a column may receive a ring 12 having a serrated edge 13 to bite into the wall of a borehole when the column is tilted and so prevent shifting along the hole. In the base of each cover 7 is a diametral recess 14 to house a detonator which may be glued into position. Electric leads, not shown, from the detonator are taken along a groove 17 in the cover which registers with a groove 18 in the sheath 1. Relay charges, e.g. tolite, may be situated on each side of the detonator.