Abstract: A thermally responsive switch device includes; a bimetallic plate enclosed within a metallic enclosure in a cantilever manner and having a central dish-shaped portion for snap movement. The bimetallic plate carries a movable contact at one free end to be in making contact relationship with a fixed contact which is placed into the enclosure. A calibrator projection is provided with the enclosure to engage with the dish-shaped portion to exert point pressure between the contacts. A reinforcer extension is disposed in the enclosure and has one end secured to the inner side of the enclosure and its other end sandwiching the dish-shaped portion in cooperation with the projection so as to prevent the cantilever support end of the plate from being deformed irrespective of often repeated snap actions of the plate in response to the ambient temperature or the like.

Abstract: A seat belt retractor incorporates a fail-safe locking mechanism that is actuated by vehicle acceleration to lock a retractor drum against rotation in the belt unwinding direction. A pair of locking wheels are arranged coaxially with the drum for simultaneous rotation therewith, and a detent movable into and out of engagement with both locking wheels is biased, by biasing means such as a spring, into engagement therewith. Normally, the detent is restrained from engagement with the locking wheels against the force of the biasing means by an actuator associated with an inertial element constituting a part of acceleration sensing means. Upon displacement of the inertial element from its normal position of rest, the actuator permits the detent to move into engagement with the locking wheels by the force of the biasing means.