부산대학교 도서관

A security mailbox is configured with a door having an arm on each side of the door that extends downward from the door into a secure mail-holding receptacle. A floor of the mailbox is constructed having longitudinally extending flaps on each side of the mailbox. Each flap has a rail/slide mounted along an underneath side close to the centerline of the mailbox, each rail having a stop at an end near the door. A link extends between a distal end of each arm and a respective rail, with a tension spring that pulls the link and arm toward each other. When the door is initially opened, the arms close the flaps within the first few degrees of door movement by movement of the slides in the rails. When the slides abut the rail stops, the rest of door movement is taken up by the springs.