Patent ID: 8720946

Claim:
A gas generator comprising: first and second pyrotechnic charges located respectively in first and second chambers, the first chamber partly delimited by a first outer wall having a first opening for releasing gas outside of the gas generator, the second chamber partly delimited by a second outer wall having a second opening for releasing gas outside of the gas generator, the first chamber provided with an igniter suitable to be triggered to ignite the first pyrotechnic charge, the second chamber having no igniter, the first chamber abutting the second chamber and being separated from the second chamber by a third wall that partially delimits the first and second chambers, the first opening closed by a first closing device that is suitable to be opened under pressure of combustion gases of the first pyrotechnic charge, the second opening closed by a second closing device that is suitable to be opened under pressure of combustion gases of the second pyrotechnic charge, a third wall including a through hole extending between the first chamber and the second chamber, the through hole being sealed in a first initial state by at least one third cap, the through hole operative to ensure permanent communication of gas directly between the first chamber and the second chamber in a second permanent state, the third cap being configured to be broken under the pressure of the combustion gases of the first pyrotechnic charge such that, when the third cap is in a broken state corresponding to the second permanent state, to permanently keep open the through hole of the third wall in said second permanent state and to let the combustion gases of the first pyrotechnic charge through said through hole permanently open in said second permanent state from the first chamber to the second chamber, where the combustion gases of the first pyrotechnic charge induce the combustion of the second pyrotechnic charge, wherein the third cap seals the through hole when the third cap is in the first initial state, and the third cap is configured to go to the second permanent state under pressure of the combustion gases of the second pyrotechnic charge, and wherein the third cap is broken in the second permanent state to permanently keep the through hole of the third wall open in said second permanent state and to let the combustion gases of the second pyrotechnic charge through said through hole in said second permanent state from the second chamber to the first chamber, such that the combustion gases of the second pyrotechnic charge induce the combustion of the first pyrotechnic charge.