Patent attributes
Apparatus (10) for helping to protect an occupant of a vehicle (12) that has a side structure (16) and a roof (18) comprises an inflatable vehicle occupant protection device (14). The inflatable device (14) is inflatable away from the vehicle roof (18) into a position between the side structure (16) of the vehicle (12) and a vehicle occupant (74). The inflatable device (14) includes overlying panels (40 and 42) that are interconnected along at least a portion of a perimeter (48) of the inflatable device to define an inflatable volume of the inflatable device. The inflatable device (14) when inflated has a predetermined thickness measured between overlying points on the overlying panels (40 and 42) at a location where the head of an occupant may contact the inflatable device. An inflation fluid source (24) provides inflation fluid to the inflatable device (14) for inflating the inflatable device. The inflation fluid in the inflatable device (14) is pressurized to a predetermined pressure when the inflatable device is inflated. The predetermined pressure is determined as a function of the predetermined thickness of the inflatable device (14).