Window insulating apparatus

Window insulating apparatus, comprising:

• (a) a plurality of panels formed of low heat-transfer material, the sum of the areas of the panels being approximately equal to that of the window opening, each panel being generally rectangular and being arranged in the window opening with the length extending horizontally, the panels being arranged in side-by-side planes and slidable vertically from an upper storage position where the panels lie side-by-side to an operative position where the panels are arranged in a step-like condition, and
• (b) an extruded element applied to the upper and lower edges of each panel, each element having a sealing surface which mates with a similar sealing surface on an extruded element applied to the immediately adjacent panel, a similar extruded element extending along each vertical edge of each panel, the sealing surface on said similar extruded element of one panel engaging the sealing surface on said similar extruded element of the immediately adjacent panel, the engagement between the sealing surfaces of said similar extruded elements taking place along the entire length of said similar extruded elements when the panels are in the storage position and engaging along only a small portion of the length of the said similar extruded elements when the panels are in the operative position.