| 摘要 |
<p>An adhesive sheet can be smoothly expanded and kept expanded. A first ring (12) is pushed into the adhesive sheet (S) from downward of the sheet (S) prior to a second ring (14) to expand the adhesive sheet (S). Subsequently, a tip of an elastic protruding piece (16) of the second ring (14) is pressed by an inner periphery of a frame (F) to bend downward. As pushed by the second ring, the tip of the protruding piece (16) comes beyond the inner periphery of the frame (F). As the first ring (12) and the second ring (14) move down from this state, the elastic protruding piece (16) recovers into an original shape, and the tip of the piece (16) engages with an upper surface of the inner periphery of the frame (F) via the adhesive sheet (S). If the first ring (12) retreats from the adhesive sheet (S), the sheet (S) is kept expanded and left on the frame (F).</p> |
