Patent ID: 8590928

Claim:
An occupant protection system for a vehicle comprising a knee airbag installed in a lower portion of an instrument panel and having a deployed condition wherein it extends rearward and upward to place a reaction surface of the airbag in contact with the instrument panel, the airbag comprising: a left lobe, a right lobe, and a central portion disposed between and joined to the left and right lobes; and a vent formed in each of the lobes on the reaction surface, a vent-bearing portion of the reaction surface immediately adjacent each vent is recessed relative to a portion of the reaction surface surrounding the vent-bearing portion, whereby the vent-bearing portion is spaced from the instrument panel such that the vents are spaced from the instrument panel to allow inflation gasses to escape from the airbag when an occupant force directed forwardly against the lobes is below a threshold level, and the vent bearing portions are urged against the instrument panel to substantially block the escape of inflation gasses when the occupant force reaches or exceeds the threshold level.