Electromechanical cylinder lock

An electromechanical cylinder lock and key arrangement comprising:

• a key that embodies a mechanical combination and includes a code transmitter for transmitting an electronic code, and
• a lock including
• a lock body,
• a turnable lock cylinder and a locking mechanism inside the lock body, the locking mechanism comprising a locking means which normally prevents turning of the lock cylinder relative to the lock body and which can be moved by means of the key into a releasing position allowing turning of the lock cylinder,
• a receiver means for receiving and identifying the electronic code transmitted by the code-transmitter of the key and comparing the received code with a stored code so that if the received code matches the stored code said receiver means enables mechanical opening of the lock by means of the key,
• a locking disc with a key opening which is so designed that the turning of the key does not directly act mechanically on the locking disc, and
• an electric operating means to be activated by means of the electronic code from the key, the electric operating means including a coupling means having a first state in which the coupling means allows the key to turn relative to the locking disc and a second state in which the coupling means couples turning movement of the key to the locking disc so that said locking disc turns with the key to a position required for opening the locking mechanism.