| 摘要 |
<p>The portable draughting aid consists of a sheet of flexible transparent plastics (1) with two parallel ridges (2) formed near each of the shorter edges. These ridges (2) form guides (3) for a straight edge (4) which is provided with matching grooves. When the straight edge is removed, the sheet (1) can be rolled up about one of the guide ridges (2) so that it can be easily transported. In an alternative design the straight edge (4) is attached by a pivot to only one guide (3).</p> |
