CLICK PEN MECHANISM ? - Autodesk Community - Inventor
Kelvin Pang on Twitter: "Geha demonstrator pendulum selector multi-pen! I don't think I have seen any other brand that shows this mechanism ^_^… https://t.co/mtwgZT4v65"
retractable pen structure
Solved: How to Make a Retractable Pen Mechanism - Autodesk Community - Inventor
How Does a Clicky Pen Work? - YouTube
PEN LOCK MECHANISM | 3D CAD Model Library | GrabCAD
Engineers Explain How Click Pens Work - Pen Vibe
7mm Pen Twist Mechanisms (Taiwanese) x 10 - Penkitzandbitz