What Is The History Of Pulleys?

The earliest depiction of a pulley appears in an Assyrian relief from the eighth century BC. This relief shows a very simple pulley that can only change the direction of force application. Its main purpose is to facilitate the application of force and does not provide any mechanical benefit. In China, the drawing of pulley devices first appeared on portrait bricks and pottery well molds in the Han Dynasty. There are also discussions about pulleys in the "Mo Jing".
The ancient Greeks classified pulleys as simple machines. As early as 400 BC, the ancient Greeks already knew how to use compound pulleys. Around 330 BC, Aristotle devoted the eighteenth question in his book "Mechanical Problems" to studying the "complex pulley" system. Archimedes contributed a lot about simple machines. Knowledge, explain the kinematic theory of pulleys in detail. 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, Hero of Alexandria analyzed and wrote the theory about compound pulleys, proving the load and force application. The ratio of is equal to the number of rope segments carrying the load, that is, the "pulley principle".
In 1608, in his book "Mathematical Collection" (Mathematical Collection), the Dutch physicist Simon Steffen showed that the ratio of the length of the moving path between the force exerted by the pulley system and the load is equal to the ratio between the applied force and the load. Inverse ratio. This is the rudimentary principle of virtual work.
In 1788, French physicist Joseph Lagrange used the pulley principle to derive the principle of virtual work in his masterpiece "Mécanique analytique", thus kicking off Lagrangian mechanics.