Patent ID: 7455655

Claim:
A disposable needleless injection device comprising a body supporting or delimiting a plurality of elements forming a circuit of elements, the circuit comprising, from upstream to downstream, an initiation device associated with a pyrotechnic gas generator, a reservoir containing a liquid active principle that is to be injected and a system for injecting the active principle, the pyrotechnic gas generator comprising a pyrotechnic charge placed in a combustion chamber, said combustion chamber being divided into two volumes by a wall, the two volumes being defined, from upstream to downstream, as a first volume in which the pyrotechnic charge is placed and a second volume, the two volumes communicating via a first device for regulating a pressure level in the combustion chamber, the injection device further comprising a membrane, furled before operation, constituting a sealed wall between the combustion chamber and the reservoir of active principle, said membrane being able, in operation, to deploy under the action of the gases originating from the combustion of the pyrotechnic charge, wherein the membrane is a cylindrical tube having a closed end and an open end, the closed end being positioned, before operation of the device, in the second volume of the combustion chamber and being positioned, after operation of the device, within the reservoir of active principle, and the membrane includes a flange extending radially outward at the open end, the closed end being positioned, before the operation of the device, upstream of the flange.