This study examines how ancient crossbows from China and Europe worked and how their designs changed during shooting. By studying historical examples and building visual models, we explored how the parts of the crossbow moved and interacted. The results show that although Eastern and Western crossbows used different ways to draw the string, both improved power and accuracy effectively. This research reveals how different cultures developed similar technological solutions.

Barbed-spring padlocks are the typical locks used in ancient China, and can be divided into three main types, namely open-keyhole, hidden-keyhole, and blocked-keyhole padlocks. With the combinations and changes of springs, keys, and keyholes, the padlocks have a variety of different unlocking methods which provide higher security. Six examples are provided to demonstrate the opening processes of blocked-keyhole padlocks.