Explosive cartridge

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. At least one spacing member ( 20 ), protruding in the axial direction, is provided on the outer side of the end wall ( 6 ) in the first end of the explosive cartridge and/or on the end unit in the second end of the explosive cartridge, such that an intermediate space ( 28 ) is formed between the outer side ( 5 ) of a first, lower explosive cartridge and the under side of the end wall of a second, upper explosive cartridge resting on the first explosive cartridge, when the two cartridges are entered in a drill hole ( 24 ) in order to be detonated, and at least one passage ( 21 ) is provided in the radial direction, passing said spacing member, allowing communication between said intermediate space and the surrounding space ( 27 ) in the drill hole.

1 - 5 . (canceled)  
   
   
       6 . Explosive cartridge comprising a substantially cylindrical sleeve having an end wall sealing a first end of the sleeve, an end unit inserted in the sleeve to a certain depth in a second end of the sleeve, said end unit having an inner side facing the interior of the sleeve and an outer side on the opposite side of the end unit, a chamber in the sleeve between said end wall and said inner side, said chamber being filled with a blasting agent, a channel extending through the end unit between an outer mouth and an inner mouth, said channel comprising a seat for a priming cartridge, 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, wherein at least one spacing member, protruding in the axial direction, is provided on the outer side of the end wall in the first end of the explosive cartridge and/or on the end unit in the second end of the explosive cartridge, such that an intermediate space is formed between the outer side of a first, lower explosive cartridge and the under side of the end wall of a second, upper explosive cartridge resting on the first explosive cartridge, when the two cartridges are entered in a drill hole in order to be detonated, and that at least one passage is provided in the radial direction, passing said spacing member, allowing communication between said intermediate space and the surrounding space in the drill hole, such that a shock wave or shock pulse, that is generated in a liquid or gel state fluid surrounding the explosive cartridge in the drill hole, can be transmitted through said at least one passage beyond said spacing member to said intermediate space for the firing of the priming cartridge.  
   
   
       7 . Explosive cartridge according to  claim 6 , wherein the priming cartridge is of the centre-fire type and that it is located at a certain depth in said channel with the rear end of the priming cartridge at a certain distance from the outer side of the en unit, such that an outer portion of the channel communicates with said intermediate space and is filled up with said fluid, when said intermediate space is filled up with fluid.  
   
   
       8 . Explosive cartridge according to  claim 6 , Wherein said channel and its outer mouth are centrally situated and that said spacing members are situated outside of said channel with reference to the radial direction.  
   
   
       9 . Explosive cartridge according to  claim 7 , wherein said channel and its outer mouth are centrally situated and that said spacing members are situated outside of said channel with reference to the radial direction.  
   
   
       10 . Explosive cartridge according to  claim 6 , wherein said spacing member or members has/have a height corresponding to not more than half the length of the priming cartridge, however to at least 10% of the length of the priming cartridge.  
   
   
       11 . Explosive cartridge according to  claim 7 , wherein said spacing member or members has/have a height corresponding to not more than half the length of the priming cartridge, however to at least 10% of the length of the priming cartridge.  
   
   
       12 . Explosive cartridge according to  claim 8 , wherein said spacing member or members has/have a height corresponding to not more than half the length of the priming cartridge, however to at least 10% of the length of the priming cartridge.  
   
   
       13 . Explosive cartridge according to  claim 6 , wherein said spacing member or members has/have a length corresponding to at most the length of the outer portion of the channel between the priming cartridge and the outer side of the end unit, however to at least 10% of the length of said outer portion of the channel.  
   
   
       14 . Explosive cartridge according to  claim 7 , wherein said spacing member or members has/have a length corresponding to at most the length of the outer portion of the channel between the priming cartridge and the outer side of the end unit, however to at least 10% of the length of said outer portion of the channel.  
   
   
       15 . Explosive cartridge according to  claim 8 , wherein said spacing member or members has/have a length corresponding to at most the length of the outer portion of the channel between the priming cartridge and the outer side of the end unit, however to at least 10% of the length of said outer portion of the channel.  
   
   
       16 . Explosive cartridge according to  claim 10 , wherein said spacing member or members has/have a length corresponding to at most the length of the outer portion of the channel between the priming cartridge and the outer side of the end unit, however to at least 10% of the length of said outer portion of the channel.