Self-balancing locking mechanism for doors

An internally-balanced locking mechanism for securing a door of a safe, comprising:

• a drive shaft mounted through the door of the safe and having an axis of rotation;
• a cam mounted to the drive shaft;
• at least two actuator plates, each having a proximal end with a lateral slot formed therein and installed about the drive shaft, and a distal end coupled to opposing locking pin-bar assemblies that are slidably supported adjacent a perimeter of the door of the safe, respectively;
• and
• at least two linkage bars, each having a proximal end pivotably coupled to the cam at a radial distance from the axis of rotation, and a distal end pivotably coupled to a mid-span of one of the actuator plates,
• wherein rotation of the cam causes the linkage bars to drive the actuator plates in opposite directions along a horizontal radial axis and engage the locking pin-bar assemblies with opposite vertical side edges of a door frame of the safe, and the at least two lateral slots bear on the drive shaft and balance off-axis loads applied by the linkage bars to the actuator plates.

A method of actuating a locking pin-bar assembly of a door to engage with a door frame, comprising:

• rotating a drive shaft mounted to the door in a first direction, the drive shaft having an axis of rotation and a rotatable cam coupled thereto;
• causing a linkage bar to drive an actuator plate along a radial axis and engage the locking pin-bar assembly with a side edge of the door frame,
• wherein the linkage bar has a proximal end pivotably coupled to the cam at a radial distance from the axis of rotation and a distal end pivotably coupled to a mid-span of the actuator plate, and
• wherein the actuator plate has a distal end coupled to the locking pin-bar assembly that is slidably supported adjacent a perimeter of the door;
• and
• causing a radial slot formed into a proximal end of the actuator plate to bear on the drive shaft and balance off-axis loads applied by the linkage bar to the actuator plate.