Abstract: To prevent the tilt of a locking member with respect to a spool even when the spool is tensioned by a seat belt in case of emergency. A second EA plate support member 16 that is integrated with a locking base 19 has a supported portion 21 having a cylindrical shape. The supported portion 21 is fitted into a locking base tilt prevention support portion 20 of a spool 9 and is supported so as to be rotatable relative to the locking base tilt prevention support portion 20 while the tilt of the supported portion 21 with respect to the spool 9 is being prevented. In this manner, even when the spool 9 is tensioned upward by a large tensional force of the seat belt 4 in case of emergency, the tilt of the center axis of the locking base 19 with respect to the center axis of the spool 9 is prevented. Thus, the EA operation of a seat belt retractor 3 is reliably and effectively performed.

Abstract: A seat belt locking buckle configured to allow a seat belt locking tongue to be stably and firmly latched and reduce the thickness of a seat belt locking buckle. When a tongue latch member is inserted into a seat belt locking buckle, an ejector is moved. Thus, a buckle latch member 13 becomes rotatable. Consequently, a slider moves along a plane that is parallel or substantially parallel to a plane of the motion of the tongue latch member and pushes a first latch guide portion of the buckle latch member. Thus, the buckle latch member is rotated from a non-latch position to a latch position. In this manner, the tongue latch member is latched by the buckle latch member.