Using Compression Spring to Bear Tension 04 July 2018, 19:30 Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch it with your favorite video player! Reason: the hooks of a extension spring are difficult for production and easy to be broken in operation. « previous mechanism Worm Drive - Multiplying Gear next mechanism » Geneva Mechanism load comments Please enable JavaScript to view the comments.