Locking mechanism with emergency opening feature useful for a safe or vault

A locking mechanism of the key lock type or code lock type for installation in a door of a vault or safe, comprising:

• at least one locking bolt for movement between a locking position in which a door is locked and an unlocking position in which the door is released for opening;
• an electromechanical actuator connected to said at least one locking bolt for moving the locking bolt between the locking position and the unlocking position;
• a first opening mechanism initiated by insertion of a key or input of a code to operate the actuator;
• and
• a second opening mechanism for operating the actuator when the key or the code is not available, said second opening mechanism including a time delay circuit so interacting with the actuator as to delay operation of the actuator for a specified time period, said time delay circuit being so positioned as to be inaccessible upon closed door and including an activation input, and
• a switch accessible from outside and communicating with the input to enable activation of the time delay circuit.