Patent ID: 7201396

Claim:
A knee protecting airbag device, wherein an airbag folded and housed on the front side of the knees of a passenger can protect the knees of the passenger when protruded rearward of the vehicle from the housed portion and expanded and inflated upward by admitting an inflating gas, wherein a lower side of said airbag when completely expanded and inflated serves as an upstream portion of said inflating gas, and an upper side of said airbag when completely expanded and inflated serves as a downstream portion of said inflating gas, wherein said airbag arranges a plurality of tethers for keeping a general sheet shape of said airbag by connecting a passenger side wall portion and a body side wall portion at the inflation completion time, wherein said tethers are constructed to enlarge the spaced distance between said passenger side wall portion and said body side wall portion at said upstream portion of the inflating gas and to reduce the spaced distance between said passenger side wall portion and said body side wall portion at said downstream portion, wherein individual tethers of the tethers are arranged in band shaves alone the transverse direction of the vehicle and at a plurality of stages in the vertical direction in the vicinity of the transverse center of said airbag having completed its expansion and inflation, and wherein a tether of said tethers is provided at a position above a lowermost tether, and has a communication port capable of releasing the inflating gas upward.