Gas generating device
First Claim
1. A gas generating device comprising:
- a combustion chamber having a primary gas exhaust port;
a gas generating composition disposed within said combustion chamber that will burn to generate a burnt gas when ignited;
igniting means disposed proximate said gas generating composition for igniting the gas generating composition;
a primary filter disposed within said combustion chamber for filtering burning residue from the burnt gas;
a cooling chamber communicating with the combustion chamber via the primary gas exhaust port;
a secondary filter, disposed in the cooling chamber, for cooling gas coming out of the combustion chamber and filtering additional burning residue from the burnt gas; and
a secondary gas exhaust port, provided in the cooling chamber, for discharging the gas filtered by the secondary filter;
the primary filter having a metal screen that is chemically inactive with respect to burnt products of the gas generating composition, said metal screen being formed of a wire mesh having a mesh size in the range of 8 to 100 wires per inch, and having a weight in the range of 20% to 80% of the weight of the gas generating composition, and;
the secondary filter including a ceramic fiber sheet having a bulk density in the range of 0.10 to 0.30 g/cm3 and a fiber diameter in the range of 1.8 to 3.0 μ
m, and being formed of silicone dioxide and alumina.
1 Assignment
0 Petitions
Accused Products
Abstract
A gas generating device for supplying gas in an air bag or the like is provided with a gas generating composition, which is burned by an ignitor to generate gas, and a primary filter for filtering the burnt gas. The gas generating composition and the filter are placed in a combustion chamber having a primary gas exhausting port. The primary filter is chemically inactive with respect to the burnt procedure of the gas generating composition. The filter has a metal screen whose melting point is equal to or higher than the burning temperature of the gas generating composition. A cooling chamber is provided which communicates via the primary gas exhausting port with the combustion chamber. In the cooling chamber is disposed a secondary filter which cools gas coming out of the combustion chamber and filters the burning residue in the gas. A secondary gas exhausting port is formed in the cooling chamber to discharge the gas filtered by the secondary filter. The secondary filter includes a ceramic fiber sheet with a bulk density of 0.10 to 0.30 g/cm3 and a filtering period of 1.0 to 6.0 sec/300 cc per 1 mm in thickness (time needed to pass 300 cc of gas through the filter).
56 Citations
14 Claims
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1. A gas generating device comprising:
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a combustion chamber having a primary gas exhaust port; a gas generating composition disposed within said combustion chamber that will burn to generate a burnt gas when ignited; igniting means disposed proximate said gas generating composition for igniting the gas generating composition; a primary filter disposed within said combustion chamber for filtering burning residue from the burnt gas; a cooling chamber communicating with the combustion chamber via the primary gas exhaust port; a secondary filter, disposed in the cooling chamber, for cooling gas coming out of the combustion chamber and filtering additional burning residue from the burnt gas; and a secondary gas exhaust port, provided in the cooling chamber, for discharging the gas filtered by the secondary filter; the primary filter having a metal screen that is chemically inactive with respect to burnt products of the gas generating composition, said metal screen being formed of a wire mesh having a mesh size in the range of 8 to 100 wires per inch, and having a weight in the range of 20% to 80% of the weight of the gas generating composition, and; the secondary filter including a ceramic fiber sheet having a bulk density in the range of 0.10 to 0.30 g/cm3 and a fiber diameter in the range of 1.8 to 3.0 μ
m, and being formed of silicone dioxide and alumina. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A gas generating device comprising:
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a combustion chamber having a primary gas exhaust port; a gas generating composition disposed within said combustion chamber that will burn to generate a burnt gas when ignited; igniting means disposed proximate said generating composition for igniting the gas generating composition; a primary filter disposed within said combustion chamber for filtering burning residue from the burnt gas; a cooling chamber communicating with the combustion chamber via the primary gas exhaust port; a secondary filter, disposed in the cooling chamber, for cooling gas coming out of the combustion chamber and filtering additional burning residue from the burnt gas, the secondary filter being secured in the cooling chamber via gaskets comprised of graphite; and a secondary gas exhaust port, provided in the cooling chamber, for discharging the gas filtered by the secondary filter; the primary filter having a metal screen that is chemically inactive with respect to burnt products of the gas generating composition, said metal screen being formed of a wire mesh having a mesh size in the range of 8 to 100 wires per inch, and having a weight in the range of 20% to 80% of the weight of the gas generating composition, and the secondary filter including a ceramic fiber sheet having a bulk density in the range of 0.10 to 0.30 g/cm3 and a fiber diameter in the range of 1.8 to 3.0μ
, and being formed of silicone dioxide and alumina.
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Specification