An Analytical Approach to the Design of Four-Link Mechanisms

The symmetry inherent in four-link mechanisms has been used in deriving a general analytical expression relating the diagonals of a four-link mechanism by means of a characteristic parameter. The nature of this expression has been analyzed. The particular case obtained by using as a parameter the square root of the sum of the squares of the lengths of the links diminished by the sum of the squares of the diagonals, has been worked out in detail and the results reduced to a form believed to be useful in design work. Design applications have been considered.