Multi-stage gas generator with thermal decoupling of the propulsive charges.

Multi-stage gas generator for motor vehicle air bags The multistage gas generator incorporates a housing with outer and inner walls, at least two combustion chambers (11, 13) filled with a driving agent (15), and igniters (7) for independent ignition of the driving agent in each of these chambers. The gas generator is characterized by a heat insulation device between the two combustion chambers. The gas generator is in the form of a pipe (3) at whose opposite ends are located the combustion chambers . At least one filter chamber (17,19) is located between the combustion chambers.