26 but offset with respect to the latter the portions 22a 22b and 22c of the profile element 24 form a generally groove or channel like structure which engages with an interference fit over a bead 28 formed along the edge of the inflation opening of the gas bag said bead 28 is formed by a reinforcing ring 30 which is sewn into the hem of the edge and consists for example of a metal wire the hem of the gas bag 32 consists of four fabric layers placed over each other in the region between the end portion 22d of the profile element 24 and the wall 20 the end portion 22d of the profile element 24 is provided with an attachment opening 34 which is in alignment with the corresponding attachment opening 18 of the wall 20 and an attachment opening 36 in the edge region 38 of a cover said cover 40 the edge region 38 of which is angled closes the open front side of the accommodating housing 10 the aligning attachment openings 36 18 and 34 are traversed by a rivet 42 which holds the edge region 38 of the cover the wall 20 the hem of the gas bag 32 and the end portion 22d of the profile element 24 together the edge portion 38 of the cover 40 also engages over the main portion 26 of the profile element 24 the profile element 24 shown in fig4 is made to match a longitudinal side of the accommodating housing 10 as can easily be seen by comparing fig2 and 4 in particular the attachment tabs 22 are arranged to match the insert slots 16 and.