Assembly of seat belt buckle and belt tightener

An assembly of seat belt buckle (1) and a seat belt tightener (3) has a seat belt buckle that is connected to a seat belt tightener by a pulling element (2). The pulling element is firmly connected within a buckle casing (4) to a buckle mechanism of the belt buckle. The pulling element, in a region directly adjacent to the buckle casing is at least partly enclosed by a cover (5). The cover has an exterior shape that is tapered towards a direction in which the buckle is pulled during a seat belt tightening process. The external dimensions of the cover in the region of its larger cross section approximate the external dimensions of the adjacent end of the buckle casing and in the external dimensions of the cover in the region of its smaller cross section approximate to the external dimensions of the pulling element. Put another way, the taper of the cover approximates a taper defined by the external dimensions of an adjacent end of the buckle casing and the external dimensions of the cable over the length of the cover.