is disposed in an instrument panel so as to open upward, the inflator is disposed in the front side of the case, the gas delivery opening of the inflator is disposed in a position more to the front side, and a front side part of the folded air bag is disposed above this gas delivery opening, and as a result of this, when the air bag deploys, this front side part of the air bag is expanded first and the air bag is expanded progressively and freely thereafter.
However, when the gas delivery opening of the inflator is merely disposed nearer front of the inside of the case with a construction wherein a front side part of the folded air bag is disposed above this gas delivery opening as101 which opens upward, and an air bag 103 is packed on the side of the opening at the top of the case 101.
In the parallel arrangement type shown in FIG. 24, a cylindrical inflator 102 is disposed in the side nearer the front of the vehicle of an upwardly opening case 101, i.e. in the side further from the passenger, and an air bag 103 is packed in the side nearer the rear of the vehicle, i.e. the passenger side.
In the series arrangement type described above, because the air bag 103 and the inflator 102 are disposed in a vertical direction, although it is possible to make the area of the opening in the case 101 small, because the whole of the air bag 103 is pushed