The earliest depiction of pulleys appeared in an Assyrian relief from the 8th century BC. This relief depicts a very simple pulley that can only change the direction of force application. Its main purpose is to facilitate force application and does not provide any mechanical benefits. In China, the drawing of pulley devices first appeared in the Han Dynasty's painted bricks and pottery well molds. There is also a discussion about pulleys in the "Ink Classic".
The ancient Greeks classified pulleys as simple machinery. As early as 400 BC, the ancient Greeks already knew how to use compound pulleys. Around 330 BC, Aristotle addressed the 18th question in his work "Mechanical Problems", specifically discussing the "compound pulley" system. Archimedes contributed a lot of knowledge about simple machinery, explaining in detail the kinematic theory of pulleys. It is said that Archimedes once used a compound pulley alone to pull a large sea ship filled with cargo and passengers. In the first century AD, Heraeus of Alexandria analyzed and wrote a theory about compound pulleys, proving that the ratio of load to force is equal to the number of rope segments that bear the load, known as the "pulley principle".
In 1608, in his work "Mathematical Collection," Dutch physicist Simon Steffen stated that the ratio of the length of the path between the applied force and the load in a pulley system is equal to the inverse ratio between the applied force and the load. This is the principle of virtual work in embryonic form.
In 1788, French physicist Joseph Lagrange used the pulley principle to derive the principle of virtual work in his monumental work "M é canique analytique", thus opening the prelude to Lagrangian mechanics.
