摘要 |
A pneumatically-operated unlocking system suitable for use on the door of a high security building such as a military weapons storage structure, in which each one of a pair of unlocking keys is provided with a different combination of holes and no holes arranged in an n-position pattern to define an n-bit binary code. An encoder outside of the building pneumatically reads the said binary codes on the two unlocking keys in sequence and transmits the resulting pneumatic binary codes through conduits in the building walls to a logic device inside thereof where the binary codes are compared to two n-bit reference pneumatic binary codes derived from a pair of reference keys located inside of said building. If the codes on the two unlocking keys match those on the reference keys, a pneumatic output is produced which can be used to unbolt the door from the building.
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