Patent ID: 7216687
Filing Date: 2007-05-15
Classification: E06B

Abstract:
1. A cord-guided covering for an architectural opening which covering has a cord tensioner, a guide cord, an upper rail, a lower rail and a blind material extending between the upper and lower rails and in which the upper rail, the lower rail or both is movable along the guide cord; the cord tensioner being positioned at or near the upper or lower rail; and the cord tensioner comprising a helically wound, extension spring that includes a first, axially stretchable, spring body having a first end and a second end and an extension limiter to prevent the first spring body from being extended further axially than a predetermined length; wherein the extension limiter is integrally formed with the first spring body by establishing a stem having a fixed end at said second end of said spring body that passes completely through said spring body to a location spaced from said first end of said spring body and defining a terminal free end of said stem, and a blocking member on said free end for selective engagement with said first end of said spring body to limit expansion of said spring body.