SEAT BELT RETRACTOR WITH ADAPTIVE LOAD LIMITING AND EXTENSION STOP FUNCTIONS

A seat belt retractor spool for a retractor providing load limiting and protraction stop functions. Spool designs are described which receive load limiting torsion bars and also having an end receiving the stop nut of a protraction limiting feature for the retractor. The spool designs provide an interface for the stop function while preserving the structural integrity of the spool.