Patent ID: 6927670

Claim:
A mechanical key device formed as a solid unit and fitted for insertion into a lock, comprising: a metal key blade with mechanical bitting to fit a pattern of a lock, a key head solidly fixed to the key blade and having a front end from which the key blade extends, an electronic identification device or memory cell in the key head, grounded on one side to the metal key device and having a data side isolated from the metal key head, the identification device or memory cell comprising a self-contained device in the form of a sealed can unit comprising a conductive metal casing with serial number ID data in a one-wire bus protocol, the casing of the identification device or memory cell comprising only two terminals on two opposed sides, one of which comprises said one side grounded to metal of the key device and the other being said data side, the key device having a data contact isolated from metal of the key device and positioned to engage with a key reading contact associated with a key slot, the data contact being connected to said data side of the self-contained device, whereby data stored by the electronic identification device or memory cell may be read by reading apparatus when the key device is inserted making said one-wire bus connection.