Pulley represents a simple device constructed for making the loading and lifting of heavyweight easier. Usually, the Pulleyhas a wheel connected to a shaft and a rope. The three crucial parts of a Pulley are the wheel, axle, and a string. The best part of using a Pulley is altering the direction and point of force application, making lifting loads easier.
The system wheel consists of deep groves to keep the rope still in its place without slipping. Also, the rope’s tension is maintained on both sides to balance the lifting and avoiding failure. The wheel moves on the shaft to facilitate the lifting. A “key” puts the shaft and wheel attached. The malfunctioning of the key can dissolve the system within fractions of a second.
Here in this video below we can see parts of pulley:
What are the types of Pulley?
Based on how the parts are attached, there are several types of PulleyPulley.
The grooved wheel is fixed to the axle, and the entire apparatus is attached to the ground. The device of such type can only change the direction of the force applied. It cannot change the movement and amount of force for lifting. This type of PulleyPulley is of limited utility.
A movable Pulley
A movable pulley has a wheel attached to a shaft, and the rope is fixed on one side only. This implies while pulling the force is reduced, and the axle is free to move. This type of pully is of high utility in lifting heavyweights.
As the name suggests, the compound pulley is a combination of the above two types of PulleyPulley. It reduces the force to half of the weight to be lifted by the setup.
Block & Tackle Pulley
This is a giant pulley where many pulley systems are combined for very heavy lifting. The system employs all the parts for maximum reduced effort in pulling heavy loads like trucks, ships, etc. It is believed that this type of PulleyPulley was first developed during the world war by Archimedes. The construction uses all the parts of the Pulley optimally for efficient lifting. This is used in industrial processes and on ships for lifting heavy loads of items.
These are used in cranes, automobile factories, aerospace, and rescue in different disasters. It’s the simplest yet boldest creation in history for reducing human effort in lifting heavy objects.