Patent ID: 7980589

Claim:
An inflatable bolster for use in an occupant compartment of a vehicle, the inflatable bolster comprising: a) an inflatable housing comprising: (i) a mounting wall which is devised to mount to a reaction structure of the vehicle; (ii) an occupant wall which is opposite the mounting wall and devised to face the occupant compartment; (iii) a substantially closed volume formed between the mounting wall and the occupant wall; (iv) a main chamber; (v) an auxiliary chamber; (vi) a flow restriction formed between the mounting wall and the occupant wall for restricting fluid flow between different areas of the housing, the main chamber and the auxiliary chamber being separated by the flow restriction; and b) a source of a pressurized fluid mounted to the housing and being in fluid communication with the substantially closed volume for inflating the housing, wherein c) the main chamber is in fluid communication with the source of the pressurized fluid, whereby during inflation the pressurized fluid flows first into the main chamber; and, d) the auxiliary chamber is in fluid communication with the main chamber whereby during inflation the pressurized fluid flows from the main chamber into the auxiliary chamber via the flow restriction at a flow rate reduced relative to fluid flowing within the main chamber during inflation of the main chamber to delay inflation of the auxiliary chamber relative to inflation of the main chamber, and e) wherein the flow restriction remains during inflation of the main chamber.