Patent ID: 7654568

Claim:
An airbag for a front passenger's seat mountable on a motor vehicle, the airbag being folded up and stored in a housing on a top area of an instrument panel in front of the front passenger's seat for deployment upward and rearward when fed with inflation gas in such a manner as to fill in a space between a top plane of the instrument panel and a windshield disposed above the instrument panel, the airbag having a generally square conical contour at inflation whose front end is the top of the square cone and comprising: a pair of outer panels located on laterals of the inflated airbag; a pair of inner panels located on an inner area in a transverse direction of the inflated airbag, each of the inner panels having a band contour curved in a generally C-shape as is flattened; an inner joint that joins inner circumferential edges of the inner panels together; a gas inlet for introducing inflation gas, at the vicinity of a lateral center of a front end of a lower side of the airbag at full inflation; a communication port located at a center in a transverse direction of an interior of the airbag at full inflation, a circumferential edge of the communication port being defined by the inner joint; a recess that recesses forward at a region corresponding to the circumferential edge of the communication port on at least a rear part of the airbag at full inflation; two raised regions located on left and right of the recess, each of the raised regions extending generally vertically in such a manner as to rise rearward relative to the recess; a contact portion where outer surfaces of the inner panels are in a face-to-face contact, wherein the contact portion is created and maintained proximate the circumferential edge of the communication port by an inner pressure of the airbag at full inflation that acts on the outer panels and inner panels and is not created if the inner pressure is less than that at full inflation of the airbag; and a generally straight portion provided at each of the inner circumferential edges of the inner panels that form an inner circumference of the contact portion, such that a shape of the contact portion is a crescent-shape, and the generally straight portion forms a chord of the crescent-shape.