Research on Synthesis of Four-bar Linkage with a Coupler Curve of Approximate Strait-line

A new synthesizing method of four-bar linkage,in which the coupler curve has the point with five-point contact(Burmester's point),is presented.With this method, the point which is on the expecting straight-line,the direction of the line and one frame point,can be given beforehand.In each condition,infinite kinds of linkages can be obtained for designers.In the article,some synthesizing formulae are derived and a few synthesizing examples are given.The results have proved that the formulae are correct.