| abstract |
This invention relates to a gas generator having two or more compartments, each with a separate initiator, with one compartment discharging before another, i.e., the compartments discharge sequentially. Each compartment has the same propellants, but the propellants have different geometries in each compartment, which results in different rates of gas evolution from each compartment. The new gas generator is designed to reach maximum inflation at the same time as the current, single stage gas generators. However, the new generator has a more rapid initial inflation, followed by a more gradual inflation rate in the subsequent stages, improving safety to occupants. n One propellant used in new generator comprises (1) ammonium nitrate as the oxidizer, which is less toxic and corrosive than the currently-used azide, (2) a fuel such as CL-20, and (3) a binder such as polycaprolactone. A second propellant comprises approximately 70-95% energetic nitramine fuel, 5-25% energetic polymer binder and 0.1-5% flash suppressant. n No hot metal particles (e.g., CuO) are generated in the new systems. This means that the complex, expensive filtering system in the current airbag systems is not needed, nor is there a need to use coated airbags. |