One embodiment is directed to a locking mechanism. The locking mechanism has a housing and a rotary actuator carried by the housing. The rotary actuator includes a shaft and armature disposed around at least a portion of the shaft. The armature is configured to rotate the shaft about a longitudinal axis...http://www.google.com.hk/patents/US8148670?utm_source=gb-gplus-share專利 US8148670 - Rotary actuator ball-detent locking mechanism
