A key safe having an outer housing for housing a key, a releasable mounting assembly, a releasable opening assembly, an electronic code entry pad, and activation circuitry is disclosed. Alternatively, the outer housing is for housing not a key, but a lever for opening a lock directly. The releasable...http://www.google.com.hk/patents/US5794466?utm_source=gb-gplus-share專利 US5794466 - Key safe for housing a key
