US Patent 8468861 Electromechanical lock and its key

An electromechanical lock, its key, and its operation method are disclosed. The method includes: during a first and a second insertion phases of a key, conveying mechanical power to an electric generator by a key follower and enabling mechanically operation of an actuator by the key follower; generating electric power from mechanical power by the electric generator; reading data from an external source; matching the data against a predetermined criterion; and during a removal phase of the key, returning the key follower to a starting position and mechanically resetting the actuator to the locked state.