Locking mechanism for a safe door

A locking mechanism for use with a door having an interior surface, an exterior surface, a plurality of sides and a plurality of corners, each corner being defined by an intersection of a pair of said sides, said door being enclosed in a frame having corners corresponding to said corners of said door, said frame defining an aperture in at least one said corner thereof, said locking mechanism comprising:

• a drive gear rotatably mounted on said interior surface of said door;
• an extension having a first gear fitted thereon, said extension being displaceably mounted on said door's interior surface to extend outwardly from a respective corner of said door, said first gear being mechanically intercooperated within said drive gear;
• a drive means mechanically associated with said drive gear adapted for permitting a user to rotate said drive gear from said exterior surface, said drive means comprising:
• a drive shaft journaled through said door;
• a handle mounted on said drive shaft adapted to be grasped and turned by a user;
• a primary gear mounted on said drive shaft and positioned on said door's interior surface;
• at least one first rack gear mechanically cooperated with said primary gear, said first rack gear being displaceable along said door's interior face;
• an elongated shaft fitted with a plurality of studs configured to form a securement engagement with said frame, said elongate shaft being mounted on said first rack gear;
• a second rack gear mounted on said elongate shaft, said second rack gear being mechanically cooperated with said drive gear, said second rack gear being adapted to rotate said drive gear upon a user's rotation of said drive shaft;
• wherein a drive means induced rotation of said drive gear effects a displacement of said extension outwardly from said door corner into a securement-producing engagement with said aperture defined with said frame corner.