Patent ID: 6911015

Claim:
A needleless syringe ( 1 , 50 , 100 ) comprising a trigger, a gas generator continued by a gas expansion chamber ( 3 , 53 , 103 ), a piston ( 13 , 76 , 113 ), an ejection tube ( 4 , 54 , 104 ), said particles being housed outside said tube ( 4 , 54 , 104 ), and the gases, emitted by said generator, bringing about the entry of the particles into the tube ( 4 , 54 , 104 ) by displacement of said piston ( 13 , 76 , 113 ), then their acceleration in said tube ( 4 , 54 , 104 ), characterized in that the piston ( 13 , 76 , 113 ) has a protective seal ( 14 , 79 , 114 ) which is calibrated in such a way that said protective seal ( 14 , 79 , 114 ) is situated upstream of the particles released into the tube ( 4 , 54 , 104 ) and, by yielding at above a threshold pressure, contributes to creating a shock wave intended to entrain said particles.