Automatic Classification of Coupler Curves of Planar Six-Link Mechanisms of the Watt-Type : 1st Report, Node and Curvature-curve

Abstract

A method for determining the nodes, the inflection points, and the maximum-and minimum-curvature points of the coupler curves of Watt six-link mechanisms is proposed for the purpose of their automatic classification. The double points of the coupler curves of mechanisms, in which the fixed and driving links are the binary links or the binary and ternary links, are determined respectively as the points that the two-link chain or the compound three-link chain, in which the end pairing points are the fixed pairing point and the coupler point, can locate their inverse positions. The nodes are distinguished by two relative angles of the component two-link chains from the ordinary intersections. A curve of the curvature of the coupler curve is presented in order to determine the remaining characteristic points and to describe the properties of the coupler curve as a single-valued function.