FIRE-RESISTANT DOOR Russian patent published in 1998 - IPC

FIELD: fire prevention technology. SUBSTANCE: this relates to fire prevention structures and facilities which ensure passive protection against spreading of open flame through door openings in buildings. Door leaf has stiffening frame which is installed inside door leaf. Stiffening frame is located close to shell located at opening side. End faces of flanges of stiffening frame are perpendicular to its supporting surface and are separated from other shell located at side of frame ledge of door by thermal-resistant insulation. Thickness of stiffening frame is less than spacing between internal surfaces of shells. Aforesaid arrangement allows for enhancing fire resistance of door without making its design more complicated. EFFECT: higher efficiency. 5 dwg