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Compound Pulley - Invented by Archimedes

 
Archimedes-Compound Pulley
: c.250 B.C.E
: Italy
: Power & Hand Tools

About Invention

Possibly by 1500 BC people in Mesopotamia used rope pulleys for hoisting water. Archimedes of Syracuse invented the first compound pulleys 287 BC - 212 BC. Plutarch reported that Archimedes moved an entire warship, laden with men, using compound pulleys and his own strength.

There are different types of pulley systems:


Fixed or class 1 pulley has a fixed axle. That is, the axle is ""fixed"" or anchored in place. A fixed pulley is used to change the direction of the force on a rope (called a belt). A fixed pulley has a mechanical advantage of 1. A mechanical advantage of one means that the force is equal on both sides of the pulley and there is no multiplication of force.

Movable or class 2 pulley has a free axle. That is, the axle is ""free"" to move in space. A movable pulley is used to multiply forces. A movable pulley has a mechanical advantage of 2. That is, if one end of the rope is anchored, pulling on the other end of the rope will apply a doubled force to the object attached to the pulley.


Compound pulley is a combination fixed and movable pulley system.

Block and tackle - A block and tackle is a compound pulley where several pulleys are mounted on each axle, further increasing the mechanical advantage.



 

Invention Images

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Compoundpulley3.png

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Compoundpulley5.png

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: http://en.wikipedia.org/wiki/Pulley
 
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