US Patent 8151608 Electronic lock box with mechanism immobilizer features

An electronic lock box contains a mechanical structure that allows the lock box to work in several different mechanical states. A first state is a key compartment door unlocking state, while a second state is a shackle release state. A third state is a “soft lock” state, which allows the key compartment door to be closed, or the shackle to be re-installed, and once this has occurred, the door will not fall open, and the shackle will not fall out. A fourth state is a “hard lock” state in which the key compartment door and the shackle are not easily disturbed by vibration or intentional impact by a would-be thief, who is attempting to unlawfully open the door or remove the shackle.