Abstract: A window frame includes a head, a one-piece stepped and sloped bottom sill and one-piece side jambs with integral sash and screen tracks. The side jambs, head and bottom sill are welded together at the corners, such that jamb walls attach to the appropriate walls of the head and sill to form a water-tight frame. The bottom sill is one-piece, with integral sloped steps that form the floors of the various sash and screen tracks. It includes an integral dam and integral internal strengthening walls that are strategically placed to support the otherwise hollow sill. The jamb, which is also one-piece, includes integral internal strengthening walls that correspond to the strengthening walls of the bottom sill, and integral track side and front walls that define the tracks for tie sashes and screen. These walls extend the length of the jamb and connect, when the frame is assembled, to appropriate walls of both the head and the bottom sill.

Abstract: A window assembly includes standard-sized sashes with lock and keeper rails that overlap and interlock such that adjacent sides of the rails are held in close proximity when the assembly is closed. The lock rail includes an exterior wall with an exterior edge that protrudes slightly. The keeper rail includes an interior wall with a first side, a substantially parallel second side and a top edge that extends between the two sides. The top edge includes an integral trough for receiving the protruding edge of the lock rail. When the assembly is closed, the protruding edge overlaps and interconnects with the keeper rail, such that the edge sits in the trough. The exterior wall of the lock rail is thus held in close proximity to the second side of the interior wall of the keeper rail and air flow between the rails is minimized. The rails preferably support strategically placed upper and lower gaskets, which are hidden from view when the assembly is closed.