Fourbar Coupler Curves
This worksheet displays the coupler curve for a four-bar linkage. Point O and point C are the ground pivots of the four-bar. Points A and B are the moving pivots. Location of the Point C = (gx,gy) can be controlled by controlling the values gx and gy using the sliders. The link lengths for links OA(a), AB(h) and BC(b) can be controlled by again using sliders. The coupler Point D traces a curve called coupler curve. To move the linkage click and hold the Point A and drag it.
Refer to the book "Geometric Design of Linkages" by Prof. J.M.McCarthy for more information.