Patent ID: 7644749
Filing Date: 2010-01-12
Classification: B25B,E04B,F16B,G09F

Abstract:
1. A system for removably holding a stretchable tension-fabric membrane in tension within a supporting frame in such a manner that said membrane is freely constrained along its perimeter by a retention strip sewn or otherwise flexibly attached to said perimeter, said system comprising a supporting frame and a stretchable tension-fabric membrane, a. said tension-fabric being a thin pliable sheet of cloth or elastomer, characterized by a high value of elastic elongation and said membrane, when lying flat and unstressed, having a defined outer perimeter and a thickness; b. said supporting frame being proportionally larger than said membrane along said perimeter thereof and comprised of a plurality of connected frame members having longitudinal anchoring channels therein, each said anchoring channel having a depth, a width, first and second channel flanges and an open gap between and defined by said flanges, said gap being narrower than said channel width and being occluded at points along said frame members where other frame members connect thereto; c. said perimeter of said membrane stretched to, and supported under tension within, said open gap along said frame members, except where said gap is so occluded, by a retention strip fastened along said perimeter by continuous stitching, welding or bonding, said retention strip being discontinuous along its said length at points corresponding to said points of occlusion in said gap; d. said retention strip being a semi-rigid ribbon of elastically deformable material with a rectangular cross-section and having a width, a thickness and a length, said width slightly less than but approximating said channel width, and said retention strip fastened along its length at the centerline of its width to said perimeter of said membrane, such that when supported in said anchoring channels behind said channel flanges, said retention strip is centered by its width within said channel width and holds said membrane substantially centered between, and free of contact with, said channel flanges of said frame members; whereby said membrane is elastically stretched, exerting thereby elastic tension upon said retention strip, and is centered along said perimeter between said channel flanges in a manner that allows the stretched membrane to assume a free tensile shape not distorted by contact with said supporting frame at any point, and whereby said retention strip may be inserted into and removed from said anchoring channels perpendicularly thereto, and thereby not obstructed at the intersections of connecting frame members, as would be the case if inserted by sliding along said anchoring channels.