Window sash assembly

A window sash assembly for use on an exterior wall surface at a window opening defined by an upper lintel, a lower sill and side members, said window sash assembly comprising a rectangular framework formed by an upper horizontal frame member, a lower horizontal frame member and a pair of vertical side frame members extending between and engaged with the outer ends of the horizontal frame members, said framework including a window covering portion adapted to overlie the window opening and at least one window panel housing portion adapted to overlie the wall surface beside the window opening, and at least one partition pillar vertically oriented between the upper and lower horizontal frame member and defining, to the opposite sides thereof, the window covering portion and the window panel housing portion, said frame members and said partition pillar having generally planar inner faces mountable against an exterior wall surface, said upper horizontal frame member including downwardly facing upper slide web means, said lower horizontal frame member including upwardly facing lower slide web means in opposed cooperative relation to said upper slide web means, and at least one window panel positioned between and slidable along said upper and lower slide web means between the window covering portion and the window panel housing portion, the window panel being completely receivable within the window panel housing portion, said partition pillar having an outer face positioned immediately inward of the upper and lower slide web means for movement of the window panel thereacross in sliding between the window covering portion and the housing portion, said window panel, when in the window covering portion, including an outer side frame member overlying the outer face of the partition pillar, and sealing means engaged between the outer face of the partition pillar and the overlying outer side frame member of said window panel.