Structural analyses of mechanisms with springs in ancient China

Mechanisms with springs were used for variety of purposes from the 2nd century BC in ancient China. Barbed-springs locks and original crossbows are representative types that belong to reconfigurable mechanisms. Several available books with mechanical illustrations introduce the structures and functions of mechanisms with springs in ancient China. However, no historical records describing the appearance or invention of the machinery can be obtained in ancient manuscripts. This work summarizes the authors' research regarding the structural analyses of barbed-springs locks and original crossbows that were described in ancient Chinese books. The historical development of mechanisms with springs in ancient China is briefly introduced first. Then, in viewpoint of modern mechanisms, the functions and components of mechanisms with springs are analyzed and presented.