Patent ID: 7954849

Claim:
Apparatus for helping to protect an occupant of a vehicle that has a side structure and a roof, said apparatus comprising: an inflatable vehicle occupant protection device that is inflatable in a direction away from the vehicle roof into a position between the side structure of the vehicle and a vehicle occupant, said inflatable vehicle occupant protection device comprising overlying panels that help define an inflatable volume of said inflatable vehicle occupant protection device, said inflatable vehicle occupant protection device when inflated having a thickness measured between overlying points on said overlying panels at a location where the head of an occupant may contact said inflatable vehicle occupant protection device; and an inflation fluid source that provides inflation fluid to said inflatable volume for inflating said inflatable vehicle occupant protection device to at least a pressure, said pressure having a functional relationship with said thickness of said inflatable vehicle occupant protection device, said functional relationship being approximated by the equation: P= (4.2×10 7 ) T −2.8 ; wherein P represents said pressure expressed in kilopascals and T represents said thickness expressed in millimeters.