US Patent 11441350 Triple sash egress window

A triple sash hung egress window allows the operable lower sash and middle sash to each travel a greater distance relative to a prior art hung window in order to give more clear space height for a given size window. This additional travel distance is achieved by raising the position of the seating flanges of each sash to be located proximate an upper surface of the top rail of the respective sash. Additionally, the profile of the sill is lowered so that a portion of the flanges of the glazing pocket of the lower sash visibly extend above the sill.