Abstract: There is disclosed a single hung aluminum window in which the sash is provided with plastic inserts in its stiles at their upper and lower ends, such inserts having portions which serve as guide and spacer members which bear against the jambs of the frame in which the stiles are positioned. The inserts also form housings which include respective pushbuttons and bias springs, the buttons extending through aligned openings in such housings and the inner stile faces. In the head portion of the frame are elongated stop members adapted to be swiveled between vertical and horizontal positions, and which in vertical positions prevent upward movement of the sash beyond the point wherein it is not engaged by the feet of the balance mechanisms mounted in the jambs.

Abstract: There is disclosed a metal window frame in which balance mechanisms are positioned in the upper portions of the jambs adjacent the sides of a fixed pane or panes, the front faces of the housings for such mechanisms being in a plane parallel to the outer face of a sash that is slidable from a closed position in the lower portion of the frame to a fully open position in the upper portion thereof. The mechanisms and sash are coupled via identical foot structures which are attached to the lower ends of the balances, and which have hook portions extending through the plane of the outer face portion of the sash so as to maintain engagement with the lower end of the sash throughout its normal movement. Catches in the jambs limit the upper position of the foot structures when the sash is raised to an uppermost position for removal from the frame.