Why the Zippo Lighter?
I'm not a smoker. But I am an engineer. And the Zippo lighter has been mentioned countless times as the gold standard for a bi-stable mechanism. The lid flings open and makes a memorable "clink" sound. What is a bi-stable mechanism? We'll get into that soon.
The Zippo dates back to the 1930's! And as far as I can tell, the design has hardly changed. By my disassemby, there are more than 20 parts, including all the rivets.
What Is A Bi-Stable Mechanism?
They are everywhere. Light switches, earbud cases, old slider phones. Bi-stable refers to something that has two stable states. In this case the lid is stable when it is closed and open. But everywhere in between, it is not stable.
Let's walk through the different states.
Let's Open Up The Lighter
To understand how the pencil works, let's take it apart to see what's inside
