Pump of Hobsons Joint 28 April 2017, 13:00 Sorry, your browser doesn't support embedded videos, but don't worry, you can download it and watch it with your favorite video player! Input shaft: blue Suction pipe: violet Discharge pipe: pink Two green pistons slide in the holes of white rotary cylinder. « previous mechanism Pin Rack Drive next mechanism » Gear and Linkage Mechanism load comments Please enable JavaScript to view the comments.