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Patent for License:

Revolutionary Pressurized Door/Window    

A door closure system for a round pressurized vessel that requires no doorframe structure to maintain doorframe rigidity.


The door frame is able to seal an opening in a round pressurized vessel without the weight and complexity of a rigid door frame structure. Because the door is part of a round surface and because of the locking connection between the door and the rest of the structure, the door does not see any bending loads, only pure tension like in a thin wall balloon. This technology is particularly beneficial where weight savings are highly valuable.

The technology consists of a specifically designed set of mating surfaces of the door frame and the door. These surfaces increase locking pressure as the pressure differential between the inside and the outside of the fuselage increases. The pressurizations forces are transmitted across the door and not around the door. The door and the door frame needs only the strength and structure of the fuselage wall. From a stress point of view, the door is transparent. However, the stretch or strain in the door closely matches the stretch or strain in the fuselage so both items stretch the same when pressurized. In the case of a window, the transparent material will need to be thicker than the rest of the structure so the amount it stretches for a given pressure will be the same as the base structure. This technology works on any pressurized vessel requiring an opening.

Primary Application of the Technology

Specific applications are the aerospace industry, either air or spacecraft. But the technology also benefits applications where unnecessary structure can be eliminated, i.e. in submarine applications or any opening in a pressurized vessel. This technology has been tested on the door of an experimental aircraft. The 5 foot diameter fuselage was filled with water and pressurized to 26psi without leaking or showing any signs of stress.

Patent Summary

U.S. Patent Classes & Classifications Covered in this listing:

Class 244: Aeronautics And Astronautics

Machines or structures adapted to be: completely or partially sustained by the air (e.g., winged aircraft, helicopters, parachutes, kites, balloons, etc.); propelled and guided or stabilized through the air (e.g., projectiles with fins, guided missiles, etc.); placed in an orbit or which substantially operate outside the earth"s atmosphere (e.g., satellites, space vehicles, etc.); or subcombinations of these machines or structures.

Subclass 129.5: Door

Class 114: Ships

Marine vehicles and accessories, as merchant vessels, warships, submarines, torpedoboats, etc., their spars, sails, and fittings specific thereto and not otherwise classifiable.

Subclass 117: Doors