Multi-stage inflatable bag for vehicular safety systems

Claim 1

In an inflatable bag safety system for vehicles to protect occupants from injury during accidents, a multi-stage airbag arranged to provide more control of the inflation performance characteristics to permit reduced risk of harm to an occupant by providing more gentle protection upon contact with the bag, comprising: a primary inflatable bag, and a secondary inflatable bag, each of a predetermined size and material; said secondary inflatable bag having an outer surface softer than said material of said primary inflatable bag; said primary inflatable bag having first port means communicating with inflation means to inflate said primary inflatable bag at a first predetermined and controlled rate with a preselected gas; said primary inflatable bag being formed of a size to fit within said secondary inflatable bag and sealed together about said first port means; said primary inflatable bag having second port means to exhaust said preselected gas into said secondary inflatable bag at a second predetermined and controlled rate slower than said first rate, and; said secondary inflatable bag having exhaust port means for exhausting said preselected gas at a predetermined and controlled rate. whereby an improved velocity control is obtained for said outer softer surface of said secondary inflatable bag during an inflation period of said inflatable bag, as shown by the lighter line in FIG. 4A of the drawings.