Patent EP-2084486-B1 (EP)
Inventor: CORD PAUL-PHILIPPE
IPC: F42B3/04
Filed: 2007-10-25
Granted: 2010-12-15
Abstract: The pyrotechnic gas generator (1) having a tubular body (2) useful in an automobile, comprises a primary chamber for storing and burning a primary pyrotechnic compound, an ignition system (11) for initiating the combustion of the primary compound to receive a predetermined signal, a secondary chamber for storing and breaking down a secondary compound, and a stabilization zone communicating with the secondary chamber and with an outside of the generator for releasing the generated gas. The primary chamber comprises nozzle for expelling the combustion products of the primary compound. The pyrotechnic gas generator (1) having a tubular body (2) useful in an automobile, comprises a primary chamber for storing and burning a primary pyrotechnic compound, an ignition system (11) for initiating the combustion of the primary compound to receive a predetermined signal, a secondary chamber for storing and breaking down a secondary compound, and a stabilization zone communicating with the secondary chamber and with an outside of the generator for releasing the generated gas. The primary chamber comprises nozzle for expelling the combustion products of the primary compound in a form of a primary jet in an axial direction of the generator. A part of the secondary chamber extends in an axial prolongation of the primary chamber. The secondary chamber having an inlet opening (14) for the primary jet. A distance separating each of the nozzle and inlet opening is lower than 2 mm. A part of the stabilization zone extends radially to a periphery of the primary chamber. The primary chamber is formed by an enclosure, which is inserted in the tubular body. The enclosure has an external dimension lower than an internal dimension of the tubular body so that an internal volume is created between the enclosure and the tubular body according to the radial direction, where the volume produces stabilization zone or a part of the stabilization zone. The secondary chamber and the stabilization zone are separated by a wall. A block is formed on the wall with respect to the each nozzle according to the axial direction, where the block is adapted to resist a pressure of the primary jet. The primary chamber has a maximum internal length (L) according to its longitudinal direction, and a maximum internal length (phi ) according to its transversal orthogonal direction, where the ratio of L/phi is higher than 1.5. The ignition system is arranged at a longitudinal end of the primary chamber. The primary compound has explosive charge (10 wt.%), which is formed by the primary and the secondary compounds. The primary chamber contains 2 grams of primary compound. The primary compound comprises double base propellant, composite propellant contains additives to adjust an oxygen balance of the primary compound, ballistic powder lova and/or pyrotechnic compositions containing copper-nitrate and guanidine nitrate. The additives are intended to absorb a part of energy of combustion products of the primary compound. An independent claim is included for a system for generating gas.