Atlas of the Four-Bar Linkage

For many years, the coupler-curve atlas by Hrones and Nelson has been a valuable aid for designing four-bar linkages. Today, computers can quickly and accurately analyze displacement, velocity, and acceleration of the coupler point which traces the curve.  However, even in the age of computers an atlas is unsurpassed as a way to rapidly compare coupler curves. In this electronic book, we retain the convenience of swiping though the pages of an atlas of linkages. However, once you have located a coupler-curve of interest, you can just tap on the diagram and bring up an interactive model. This allows you to explore intermediate parameters and observe the motion directly. This atlas provides a broad range of interactive diagrams of Crank Rockers, Double Cranks, Crank Sliders, and Inverted Crank Sliders, along with their selection of coupler-curves.


This electronic atlas contains an additional section which presents essential mechanical information on all the mechanisms in the book. The ratio between coupler velocity and crank angular velocity (or, equivalently, the ratio of input torque to output force) is presented.