Perforator-injector with an internal percussion mass

Claim 1

A device for perforating a strong wall and for injecting an active fluid through said wall, comprising: a cylinder having an upstream part (2) and a downstream part (3), said upstream part defining a power chamber capable of being fed by a power fluid delivered from a source of power fluid under high pressure, a downstream part (3) having an opening (3a) for admission of said active fluid, said upstream part (2) being provided with orifices (7) for the escape of air and combustion gases, combustion gases, a piston (1) placed in said cylinder (2, 3), said piston comprising a tubular rod (1a) forming an injection channel and a head (1b), said head (1b) having an upstream zone (1c), said tubular rod (1a) being capable of sliding in the downstream part (3) of the cylinder, whereby said opening (3a) communicates with said rod (1a) only when said piston (1) slides and is substantially in abutment on the end of said downstream part (3) of said cylinder (3), a percussion mass (4) having an upstream end, said upstream end having a frangible positioning element, said percussion mass having a downstream zone (4a) interposed between said head (1b) of said piston and the source of high pressure power fluid, said mass being initially kept at a distance from the head (1b) of the piston and being able to slide in said cylinder (2, 3), wherein an internal ferrule (6) surrounds said percussion mass and is interposed between said percussion mass (4) and said upstream part (2) of the cylinder, said ferrule (6) having an enlarged chambering downstream of the downstream zone (4a) of said percussion mass (4) with perforations which communicate with said orifices (7).

Claim 2

A device for perforating a strong wall and for injecting an active fluid through said wall, comprising: a cylinder having an upstream part (2) and a downstream part (3), said upstream part defining a power chamber capable of being fed by a power fluid delivered from a source of power fluid under high pressure, a downstream part (3) having an opening (3a) for admission of said active fluid, said upstream part (2) being provided with orifices (7) for the escape of air and combustion gases, combustion gases, a piston (1) placed in said cylinder (2, 3), said piston comprising a tubular rod (1a) forming an injection channel and a head (1b), said head (1b) having an upstream zone (1c), said tubular rod (1a) being capable of sliding in the downstream part (3) of the cylinder, whereby said opening (3a) communicates with said rod (1a) only when said piston (1) slides and is substantially in abutment on the end of said downstream part (3) of said cylinder (3), a percussion mass (4) having an upstream end, said upstream end having a frangible positioning element, said percussion mass having a downstream zone (4a) interposed between said head (1b) of said piston and the source of high pressure power fluid, said mass being initially kept at a distance from the head (1b) of the piston and being able to slide in said cylinder (2, 3), wherein an internal ferrule (6) surrounds said percussion mass and is interposed between said percussion mass (4) and said upstream part (2) of the cylinder, said ferrule (6) having an enlarged chambering downstream of the downstream zone (4a) of said percussion mass (4) with perforations which communicate with said orifices (7).