In this paper, Grashof’s theorem is justified from the perspective of the occurrence of stationary configurations and uncertainty configurations of four-link chains. The link length relations at stationary configurations and uncertainty configurations are examined in detail based on the triangle inequality, and then the conditions for the existence of a crank and a change point are deduced.
Chang, Wen-Tung; Lin, Chen-Chou; and Wu, Long-Iong
"A NOTE ON GRASHOF THEOREM,"
Journal of Marine Science and Technology: Vol. 13:
4, Article 1.
Available at: https://jmstt.ntou.edu.tw/journal/vol13/iss4/1