| 摘要 |
<p>A sign has a rigid peripheral frame extending around an opening lying in a plane, and a sheet of flexible sign material extends across the opening. The frame has an edge surrounding the opening, and the flexible sign material has a peripheral edge portion extending over the edge and rearwardly from the plane of the opening. A series of separate sheet tensioning devices is spaced around the frame rearwardly of the plane of the opening, each tensioning device comprising means for retaining the peripheral edge portion of the flexible sign material and means for adjusting the position of the retaining means relatively to the frame to cause the peripheral edge portion of the flexible sign material to be pulled rearwardly across the frame edge to tension the flexible sign material across the opening. Each retaining means includes a first member having a recess extending longitudinally of and facing the frame edge, the recess being open at at least one end of the first member, and a second member having a first part engageable by the adjusting means and a second part insertable into the recess in the first member by relative longitudinal movement into an open end thereof. The recess of the first member and the second part of the second member are shaped to cause the first member to prevent movement of the second part of the second member out of the recess in a forward direction, and the peripheral edge portion of the flexible sign material is wrapped around the second part of the second member in the recess and thereby retained by the tensioning device.</p> |
