Synthesis of Planar Six-Link Path-Generator : Part 1, On the Cusps of Stephenson-I Mechanism

抄録

In former studies for the cusps on coupler curves, only the number of cusps for some special types of six-link mechanisms was obtained, and mechanisms having cusps have not yet been synthesized. In the present paper, the Stephenson-I mechanism among three types of six-link path-generators is described. First the types of cusps are classified, and the number and positions of them are defined. Then considering the four- and degenerated six-link mechanisms which are equivalent to general six-link ones in the neighbourhoods of cusps, the inclinations of tangents at cusps are obtained. Further, a new method for expressing the error between the ideal and generated curves is suggested, and as a result, the synthesis of a six-link mechanism is carried out such as to satisfy the number and positions of cusps, the inclinations of tangents at cusps, and the shape of the ideal curve.