Structural analysis of traditional Chinese blocked-keyhole padlocks

Abstract. The use of locks has a history thousands years. Barbed-spring padlocks are the typical used in ancient China and can be divided into three main types, namely open-keyhole, hidden-keyhole, blocked-keyhole padlocks. Since mechanical structures differ terms opening process, they reconfigurable mechanisms. With combinations changes springs, keys, keyholes, have variety different unlocking methods which provide higher security. This work uses variable chains to analyze representations joints presented first. characteristics representative barbed-spring introduced. Six examples provided demonstrate processes result shows that it is useful tool realize structural difference during operation.