Knee protecting airbag device

A knee protecting airbag device comprising:

• an airbag folded and housed in a case to be fixed on the vehicular body side in front of the knees of a seated passenger, such that the upper edge side is closer to the lower edge side,
• wherein said airbag is protruded rearward of a vehicle from said case and expanded and inflated upward, when an inflating gas flows in, so that it can be arranged on the front side of the knees of the passenger between a member on the body side and the passenger thereby to protect the knees of said passenger,
• wherein said airbag is constructed into a flat airbag which is formed by joining the outer peripheral edges of a passenger side wall portion and a body side wall portion to each other,
• wherein said passenger side wall portion is arranged on the passenger side at the time of inflation completion,
• wherein said body side wall portion is arranged on the vehicular body side, and
• wherein said body side wall portion has a flat shape substantially identical to that of said passenger side wall portion,
• wherein said airbag is so connected to and held in said case that the portion on the side of said body side wall portion which is near the lower edge of the completely inflated airbag may be pulled to the vehicular front side in said case, and is folded and housed in said case.

A knee protecting airbag device,

• wherein there is arranged in front of the knees of a seated passenger a case which houses and holds a folded airbag and an inflator for feeding an inflating gas to said airbag,
• wherein said case can protrude said airbag, when said airbag is expanded and inflated, rearward of the vehicle from an opening,
• wherein said inflator is arranged in its axial direction transversely of the vehicle and includes a generally column-shaped body and a diffuser,
• wherein said body has gas discharge ports on its one axial end side and capable of discharging the inflating gas,
• wherein said diffuser is constructed to cover said body and to guide the inflating gas from said body,
• wherein said inflator is housed and held in said case such that said gas discharge ports are arranged on one edge side of said case in the vehicular transverse direction and such that it is housed in said airbag,
• wherein said diffuser includes a cover portion for covering the periphery of said gas discharge ports, and a gas outlet port for introducing the inflating gas from said gas discharge ports into said airbag, and
• wherein said gas outlet port is opened such that the central portion in the vehicular transverse direction is higher but the portions on the two left and right sides of said central portion are generally equal to each other but smaller than said central portion, with respect to the velocity of the inflating gas rearward of the vehicle in said airbag in the vicinity of the opening of said case.

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 said airbag provides the lower side, when completely expanded and inflated, for an upstream portion of said inflating gas and the upper side, when completely expanded and inflated, for 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, and
• 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.