Air bag inflator and method of assembly

A method of assembling an apparatus for inflating an inflatable vehicle occupant restraint, said method comprising the steps of:

• placing a circular spacer coaxially within a cylindrical housing, said housing having a longitudinal central axis, a tubular wall with a plurality of gas outlet openings, and an end wall defining a closed end of said housing, said spacer being located adjacent to said end wall and having a plurality of radially projecting spacer lobes at locations that are spaced from each other circumferentially around said spacer;
• placing an annular elastomeric seal concentrically over said spacer in a position extending circumferentially across and between said spacer lobes;
• placing a cylindrical tubular structure coaxially within said tubular wall of said housing, said tubular structure including a cylindrical filter extending circumferentially around said axis and having an inner end portion located adjacent to said end wall;
• and
• pressing said tubular structure forcefully into said housing along said axis so as to press said inner end portion of said tubular structure forcefully against said seal;
• said step of pressing said tubular structure into said housing causing said seal to become compressively loaded axially between end wall and said tubular structure and radially between said tubular wall and said spacer lobes.