Flexible sheet rollup window structure

Claim 1

The combination of a window frame having spaced apart, longitudinally extending side members and first and second end members extending transversely between said side members in longitudinally spaced relationship thereby defining a window opening: a rollup window structure for interpositioning in the window frame comprising a guide roller supported by and extending transversely across the window frame closely adjacent the first end member thereof, a storage roller supported by and extending transversely across the window frame in spaced parallel relationship to said guide roller, an elongated, thin sheet having longitudinal edges and formed from an air impervious flexible material secured at one end to said storage roller and adapted to be selectively rolled up thereon or unrolled, trained around said guide roller and extended across the window frame in closing relationship to the window opening, said sheet being provided with a longitudinally extending flat surfaced rib of predetermined width continuously secured throughout its length along each marginal edge portion thereof in parallel relationship to a respective edge and projecting in upstanding relationship to a surface of said sheet so as to be interposed between said sheet and said guide roller, said sheet carrying a transversely extending weather strip at a position to engage the first end member of the window frame in fluid sealing relationship therewith when said sheet is fully extended, and a rigid structural member attached to an opposite end of said sheet in transversely disposed relationship and displaceable longitudinally with said sheet either into or out of sealing engagement with the second end member of the window frame, and longitudinally extending edge seal guides disposed at and mounted on each vertical side member of the window frame and cooperatively engaging with a respective longitudinal marginal edge portions of said sheet and associated rib in sealing relationship therewith.