Abstract: This invention relates to a highly effective fire-proof window consisting of at least one glass sheet mounted in a frame, the frame being such that when the glass sheet is exposed to the effect of heat in a fire, it will be subjected to a somewhat uniform heat effect thus preventing breakage due to the buildup of stresses. Uniform heating is produced by the inclusion of a covering along the edge of the glass which falls away upon heating of the window.

Abstract: This invention relates to a fire-proof window consisting of at least one glass sheet mounted in a frame and which permits generally uniform heating of the glass sheet when exposed to the effect of heat in a fire thus preventing breakage due to the buildup of stresses. Uniform heating is produced by the inclusion of a listel along the edge of the glass which is moved away from the glass by means of a member disposed between the listel and glass. This member expands in volume under the effect of heat to push the listel away from the glass sheet.