panel 4 by means of bolts 46 and 48 through the flanges 42 and 44 on the other hand the airbag main unit 8 is provided with a mounting bracket 50 welded or otherwise secured to the bottom wall 36 after aligning four bolt holes 52 formed in the left and right sides of the bottom wall 36 of the airbag fitting 32 with corresponding bolt holes formed in the mounting bracket 50 bolts 54 are fastened by nuts 56 so as to secure the airbag main unit 8 to the airbag fitting 32 further a pipe shaped support cross beam 60 transversely extends in front of the instrument panel 4 such that its opposite ends are connected to the left and right frames of the vehicle chassis to the support cross beam 60 are connected anchoring brackets 62 which are anchored to the front edge of the airbag fitting 32 referring to fig4 a to 4c each of these anchoring brackets 62 is comprised of a connecting portion 64 and an anchoring portion 66 bent 90 u00b0 with respect to the connecting portion 64 the anchoring bracket 62 is formed with a specific length of slot or oval hole 68 extending in the lengthwise direction in the connecting portion 64 and a u shaped hook 70 forming an open area 70a by a curved portion 70c on the rear side at the tip end of the anchoring portion 66 the anchoring bracket 62 is connected to an attachment bracket 72 see fig2 secured to the support cross beam 60 at the connecting portion 64 by a bolt 74 through the oval hole 68 the airbag fitting 32 is provided with insertion slots 80 formed in the rear portion of the bottom wall plate 36 thereof into which.