| 摘要 |
<p>A marking instrument, e.g. a felt tip marker, has a retractable marking tip (4) carried by a marker unit (5) housed within the barrel, and a rolling diaphragm (10) connecting between the marker unit and barrel to form a sealed envelope around the tip (4) when the tip is retracted. Upon retraction of the tip, the marker unit rotates to twist the diaphragm and close the envelope.</p> |
