Abstract: A rock cracker cartridge (1) contains a cracking powder charge (6) and an ignition capsule (30) with an ignition powder charge (29) in an ignition unit sleeve (31) which does not possess the mechanical strength that would be required for the ignition powder charge to be exploded in the open air when ignited. In the rock cracker cartridge there is also provided an ignition assembly sleeve (7a) which surrounds the ignition unit sleeve when the rock cracker cartridge is primed. In combination, the assembly which surrounds the cracking powder charge, and which comprises the ignition unit sleeve and the ignition assembly sleeve, has a sufficient strength for an adequate pressure to be developed in the assembly such that the ignition powder charge will explode and generate a flame of fire and the ignition unit sleeve as well as the ignition assembly sleeve be penetrated by the pressure and the flame of fire, said flame offire igniting the cracking powder charge.

Abstract: A powder charged rock cracker cartridge (1) comprises asubstantially cylindrical outer sleeve (2) with an end wall in a first end (3); a plug (4) which, enclosing said outer sleeve, is inserted into and is secured in an opposite second end of the outer sleeve; a main chamber (5) in the outer sleeve (2) between said end wall and said plug, which main chamber is filled with a blasting powder charge (6); a substantially cylindrical inner sleeve (7), which is coaxial with the outer sleeve (2), is connected to said plug, and extends into the charge of blasting powder in the main chamber; and a central through hole (8) in said plug which communicates with the inner sleeve, which is closed in its inner end, which is inserted into the blasting powder charge. The hole in the plug and the inner sleeve in combination form a priming chamber (9) having a shape corresponding to the outer shape of a detonator (10), which can be trigged electrically and comprises an igniting powder charge.

Abstract: An explosive cartridge includes a substantially cylindrical sleeve (2) having an end wall (6) sealing a first end of the sleeve, an end unit (3) inserted in the sleeve to a certain depth in a second end of the sleeve, said end unit having an inner side (4) facing the interior of the sleeve and an outer side (5) on the opposite side of the end unit, a chamber (7) in the sleeve between said end wall and said inner side, said chamber being filled with a blasting agent (8), a channel (10) extending through the end unit between an outer mouth (11) and an inner mouth (12), said channel comprising a seat (13) for a priming cartridge (14), and a priming cartridge accommodated in the seat, said priming cartridge containing a detonating explosive for the firing of the blasting agent in said chamber.