Fail-safe access control chamber security system

A method of controlling access through a double-door system, the method comprising the steps of:

• providing a first lockable door;
• providing a second lockable door;
• providing an enclosed chamber between said two doors;
• providing a metal detector located to detect a metal object being disposed between said two doors;
• providing means to detect a presence of a person within said enclosed chamber;
• providing means to detect when a person touches said second door;
• unlocking said first door;
• locking said second door;
• locking said first door when the means to detect a presence of a person detects the presence of a person within the chamber;
• determining if said metal detector has detected a metal object;
• unlocking said second door when said metal detector has not detected a metal object and when the means to detect when the person touches the second door detects that the person touches the second door;
• enabling said metal detector when the presence of a person is detected and said first door is locked;
• and
• disabling said metal detector when said means to detect detects a person touching said second door.

An access control vestibule, comprising;

• a vestibule frame having a rectangular shape configured to form an access control vestibule mounted in said vestibule frame;
• an entrance door frame and an exit door frame;
• a panel mounted in said vestibule frame and forming a side wall section of said vestibule;
• a panel mounted in each of the door frames and forming an entrance door and an exit door;
• said entrance door and said exit door both being manually operated, each formed of a single swinging door, and each swingable towards the outside of said vestibule;
• a lock associated with each of the doors;
• a metal detector located to detect a metal object being disposed between said entrance and exit doors;
• and
• control means to prevent both doors from being unlocked at the same time when said metal detector detects a metal object.