The top hung sash assembly of the invention comprises a hinge bar and a frame assembly hingedly connected to the hinge bar. The frame assembly includes a head extrusion member, a sill member and two side members with at least one glazing member mounted therein. The head extrusion includes a first flange...http://www.google.se/patents/US5136812?utm_source=gb-gplus-sharePatent US5136812 - Top hinged sash construction and associated window construction and related methods
