Appartus and method for preventing unwanted opening of a locked enclosure

A method of preventing unwanted opening of a locked enclosure having a door and door bolt, the door openable when the door bolt is retracted from a structure surrounding the enclosure, comprising:

• maintaining an arm in a first position relative to a frangible guard plate with the arm under a bias of a spring;
• freeing the arm for movement from the first position when the frangible guard plate is fractured;
• and
• moving the arm under the bias on the arm into engagement with the door bolt in the second position, thereby preventing retraction of the door bolt.

An apparatus for preventing unwanted opening of a locked enclosure including a lock mechanism, comprising:

• an arm having first and second ends and rotatably mounted at a point between the first and second ends;
• a first spring operatively coupled to and rotatably biasing the first end in a first direction;
• a second spring operatively coupled to and rotatably biasing the second end in the first direction;
• and
• a frangible guard plate coupled to the first end of the arm by the first spring, thereby preventing rotation of the arm in the second direction from a first position to a second position, wherein the arm in the second position is positioned to engage with a portion of the lock mechanism, thereby preventing the opening of the locked enclosure;
• wherein when the frangible guard plate is fractured, the arm is free to move to the second position due at least in part to a second bias from the second spring.

A method of preventing unwanted opening of a locked enclosure including a lock, comprising:

• rotatably mounting an arm to a housing at a point between first and second ends of the arm;
• coupling one of the first or second ends of the arm to a frangible guard plate, thereby maintaining the member in a first position relative to the frangible guard plate with the arm under a first bias;
• freeing the arm for movement from the first position when the frangible guard plate is fractured;
• and
• rotating the arm into engagement with a member of the lock in a second position, thereby preventing opening of the locked enclosure.

An apparatus for preventing unwanted opening of a locked enclosure, the enclosure including a lock mechanism, comprising:

• a frangible guard plate;
• and
• an arm coupled to the guard plate by a spring, thereby maintaining the arm in a first position under a bias of the spring, the bias in a direction transverse to a surface of the frangible plate;
• wherein the arm is positioned to engage with the lock mechanism in the second position, thereby preventing the opening of the locked enclosure.

A method for preventing unwanted opening of a locked enclosure, the enclosure including a lock mechanism, comprising:

• coupling a frangible guard plate and an arm by a spring, the arm thereby being under a bias in a direction transverse to a surface of the frangible guard plate;
• freeing the arm for movement from the first position when the frangible guard plate is fractured;
• moving the arm to a second position;
• when the arm is in the second position, engaging the lock mechanism and thereby preventing opening of the locked enclosure.