Gas generator for low-slag gas cartridges for motor vehicle safety

Abstract

The invention relates to a gas generator, especially for an air bag, having two tubes ( 9, 10 ) arranged concentrically one in the other, the inner tube ( 10 ) forming the combustion chamber, containing the fuel ( 3 ), and being closed by a cover plate ( 11 ) and an end plate ( 12 ). The gas generator is especially suitable for the use of laughing gas and has a cover plate ( 11 ) joined to an end plate ( 12 ) by an igniter tube ( 7 ) passing through the combustion chamber. An ignition element is disposed in the cover plate, whose discharge opening for the ignition gases is in communication with the igniter tube ( 7 ). A longitudinally displaceable piston ( 2 ) is disposed in the igniter tube ( 7 ), and radial openings ( 6 ) into the combustion chamber are disposed in the igniter tube ( 7 ). The igniter tube ( 7 ) is connected with an outlet in the end plate ( 12 ).

It is claimed:  
     
         1 . A gas generator comprising: 
 an inner tube and an outer tube arranged concentrically one in the other, said inner tube forming a combustion chamber, containing fuel and being closed with a cover plate and an end plate;    an igniter tube extending through said combustion chamber and joining said cover plate to said end plate;    an ignition element disposed in said cover plate, said ignition element having an outlet opening for the ignition gases in communication with said igniter tube;    a longitudinal displaceable piston disposed in said igniter tube;    said igniter tube having radial openings into the combustion chamber disposed therin;    said igniter tube being joined in the end plate to an outlet.    
     
     
         2 . The gas generator according to  claim 1 , wherein a discharge chamber is disposed in said end plate, said outlet of said igniter tube opening into said discharge chamber, said discharge chamber being connected through blowout openings to an afterburning chamber disposed between said outer tube and said inner tube.  
     
     
         3 . A gas generator according to  claim 1 , wherein said piston is joined to said cover plate with a break-away edge.  
     
     
         4 . A gas generator according to  claim 1 , wherein an area for receiving said piston is disposed in said discharge chamber behind said discharge openings in the direction of flow.  
     
     
         5 . A gas generator according to  claim 1 , wherein the number of radial openings in said igniter tube increases toward said outlet chamber.  
     
     
         6 . A gas generator according to  claim 1 , wherein discharge openings are disposed in said outer tube.  
     
     
         7 . A gas generator according to  claim 1 , wherein said discharge openings and said blow-out openings are closed by a membrane.  
     
     
         8 . A gas generator according to  claim 7 , wherein after the ignition of said ignition element said piston tears open the blow-out openings.  
     
     
         9 . A gas generator according to  claim 1 , further comprising cooling elements disposed in said afterburning chamber.  
     
     
         10 . Fuel for use in a gas chamber comprising nitrous oxide and at least one organic substance  
     
     
         11 . The fuel of  claim 10 , wherein said organic substance is selected from the group consisting of polyethylene, starch and paraffin.