Seatbelt retractor

A seatbelt retractor comprising:

• a refractor frame;
• a spindle supported by the retractor frame and being freely rotatable;
• a lock member that is supported by the retractor frame and configured to become fixed to the retractor frame when acceleration exceeds a predetermined value;
• a torsion bar that is disposed on a force transmission path between the spindle and the lock member and includes a plurality of shaft parts having different twisting torques;
• and
• a switching device for switching the plurality of shaft parts of the torsion bar forming the force transmission path,
• wherein the switching device includes a switch piston, a gas generator, and a switch housing having a gas generator housing portion defining a bore in which the gas generator is received, the switch housing having a gas flow passageway that communicates with the bore so that gas generated by the gas generator passes through the gas flow passageway to the piston,
• the gas flow passageway being located between the bore and the piston and being formed in the switch housing diagonally with respect to central axis through the bore, and
• a hole defined in the switch housing on an sidewall of the bore that is opposite from the gas flow passageway, the gas generator being positioned in the bore between the hole and the gas flow passageway and blocking the hole so as to prevent gas generated by the gas generator from flowing out of the hole.