Abstract: In a door assembly composed of a door frame, a door having a hinge side and a hinge supporting the door on the frame for pivotal movement of the door between an open position and a closed position, the hinge side of the door facing, and being adjacent to, a portion of the frame when the door is in the closed position, the door is provided with a recess in the hinge side; and the assembly is further provided with at least one projecting element secured to the frame portion to project into the recess when the door is in the closed position and having a mass of thermally intumescent material which is expandable for securing the projecting element to the door upon being heated above a predetermined temperature.

Abstract: A gear hinge having a thrust bearing which is less likely to wear. The hinge may include, in various combinations, gears having relatively small, rounded teeth, hinge members having anodized surfaces, bearings which may be produced by a gas assisted injection molding process and bearings which are relatively hard.

Abstract: A gear hinge having a trust bearing which is less likely to wear. The hinge may include, in various combinations, gears having relatively small, rounded teeth, hinge members having anodized surfaces, bearings which may be produced by a gas assisted injection molding process and bearings which are relatively hard.