FIRE DOOR AND FIRE DOOR LATCH Russian patent published in 2006 - IPC E06B5/16 

FIELD: building, particularly fire doors.

SUBSTANCE: fire door comprises at least one door leaf with metal case forming outer door leaf surfaces, heat insulation means, stiffening frame and lock with latching mechanism, as well as door frame with ledge and hinges to connect the door leaf to the door frame. The heat insulation means is multilayered and includes two outer layers adjoining metal case but non-connected with it and at least one inner layer. Outer heat insulation means layers are made of material having greater heat conductivity and greater rigidity in comparison with that of inner layer material. The stiffening frame is arranged inside the door leaf and formed of U-shaped profile having central part fixedly connected with end surfaces of the door leaf along perimeter thereof. Both flanges are arranged in inner layer of the heat insulation means. The door has two latches snapped into action under the action of heat. The latches are located at end surfaces of the door leaf in corners thereof from door frame ledge side and spaced maximal possible distance from the hinges.

EFFECT: increased fire-resistance.

19 cl, 10 dwg