https://hackaday.com/2017/03/29/marvelous-mechanisms-the-ubiquitous-four-bar-linkage/
Marvelous Mechanisms: The Ubiquitous Four Bar Linkage | Hackaday
Jun 6, 2018 - The four bar linkage is a type of mechanical linkage that is used in many different devices. A few examples are: locking pliers, bicycles, oil well pumps,...
four bar linkagemarvelousmechanismsubiquitoushackaday