Inflator capable of modulation air bag inflation rate in a vehicle occupant restraint apparatus

An airbag inflator comprising:

• a housing;
• a combustion chamber provided in the housing;
• a reservoir provided in the housing for containing a liquid propellant;
• a piston slidingly received in the housing and having a first piston head separating the combustion chamber from the liquid propellant reservoir;
• an injection port;
• a pyrotechnic initiator, detonated in response to a vehicle accident, to pressurize the combustion chamber and to ignite liquid propellant injected into the combustion chamber from the reservoir through the injection port during a regenerative pumping stroke of the piston, combustion of the injected liquid propellant producing airbag inflation gasses;
• and
• a controller varying a rate of the piston's regenerative pumping stroke according to at least one accident parameter, thereby regulating a rate of airbag inflation during airbag deployment.

An airbag inflator comprising:

• a housing;
• a combustion chamber provided in the housing;
• a reservoir provided in the housing for containing combustible fluid;
• a piston slidingly received in the housing and having a first piston head separating the combustion chamber from the combustible fluid reservoir;
• an injection port;
• a initiator, activated in response to a vehicle accident, to pressurize the combustion chamber and to ignite combustible fluid injected into the combustion chamber from the reservoir through the injection port during a regenerative pumping stroke of the piston, combustion of the injected combustible fluid producing airbag inflation gasses;
• and
• a controller including at least one sensor, the controller varying a rate of the piston's regenerative pumping stroke according to at least one accident parameter, thereby regulating a rate of airbag inflation during airbag deployment.