Abstract: An apparatus for sealing a movable closure member about an access aperture located within a rigid structure. The movable closure member is sized to cover the access aperture and to provide access through the access aperture when open. A resilient elastomeric gasket is secured to one of the rigid structure or the movable structure to suit design and manufacturing preference. The resilient elastomeric gasket has a hollow cavity disposed within the elastomeric gasket, and the hollow cavity is sealed at each end to form a pressure-equalizing chamber therein. A convex protrusion is positioned on the elastomeric gasket to confront a flat stop positioned upon the other of the rigid structure or the movable structure when the movable structure is closed. A closure means is provided to bias the convex protrusion against the flat stop face with sufficient pressure to partially deform the resilient, elastomeric gasket.

Abstract: An adjustable, quick acting balanced beam latching apparatus for a fluid tight door, hatch or scuttle mounted in an aperture in a bulkhead, wall or deck onboard ships, aircraft and other liquid or gas tight structures. A box frame is secured in an aperture in the bulkhead, and a fluid tight door is pivotally secured to one side of the box frame by suitable door hinges. A plurality of rotating dogs are pivotally secured to retract within the box frame in the retracted position, and to extend through apertures in the box frame when in the extended position. A plurality of balanced beam linkage members are rotatably secured to the rotating dogs. A plurality of connecting rods are rotatably secured to the balanced beam linkage members, and to each other. An operating link is pivotally secured at one end to a central connecting rod, and pivotally secured at the opposite end to an operating crank arm which is secured through an aperture in the door frame.