Patent ID: 8307880
Filing Date: 2012-11-13
Classification: B44D

Abstract:
1. A sheet material tensioning apparatus comprising: a plurality of frame members interconnected to form a closed contour, each of said frame members including a forward face and a rearward face, said forward face having formed thereon a protrusion extending from an edge thereof along an outer periphery of said closed contour, said protrusion forming a material-supporting edge in a plane around said closed contour; a material fastening mechanism for affixing sheet material to said frame members over said closed contour; at least one expansion mechanism imposing a separation between said frame members so as to expand said closed contour; an edge-bridging mechanism spanning said separation between each of said frame members and maintaining continuity of said plane of said material-supporting edge at said separation as said closed contour expands; and a crossbar assembly extending across said closed contour and interior thereto, said crossbar assembly including: a plurality of braces each received in a corresponding one of said frame members, said braces having a hollow interior divided by a plurality of dividing walls, said dividing walls defining a plurality of longitudinal chambers; a joining device interconnecting said braces, said joining device having expanding elements inserted into a corresponding one of said longitudinal chambers of said braces, said joining device including an expansion actuator cooperating with said expanding elements to apply an outward force to all interior walls of said corresponding one of said longitudinal chambers, each of said corresponding frame members has formed thereon an opening on an inner periphery of said closed contour, said opening having captured therein a tube section receiving a corresponding one of said braces.