| 摘要 |
<p>An auto-retractable pen comprises a pen and a cap. The pen comprises a hollow case, a middle screw piece, an ink cartridge, a mechanical spring and a mobile magnetic element. The cap comprises a cap body and a stationary permanent magnet. The pen is capable of attaching to the cap by the magnetic attraction force in a single-hand operation when a user places the mobile magnetic element of the pen in proximity to the stationary permanent magnet of the cap. The writing tip of the pen retracts into the hollow case of the pen when an upward magnetic attraction force becomes greater than a downward mechanical expansion force. The middle screw piece is capable of adjusting the strength of the cushion effect by the mechanical spring according to Hooke's Law. This invention relates to retractable pens, and the principal use of the invention is for operating a pen with a single hand.</p> |
