Mechanism Guides Hatch Through Hatchway

Elliptical hatch designed to move through hatchway to make pressure-assisted seal with either side of bulkhead. Compact three-degree-of-freedom mechanism guides hatch through hatchway or holds hatch off to one side to facilitate passage of crew and/or equipment. Hatches and mechanisms used in submarines, pressure chambers (including hyperbaric treatment chambers), vacuum chambers, and vacuum-or-pressure test chambers.