PULLEY BLOCK Meaning and
Definition
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A pulley block is a mechanical device composed of one or more pulleys, also known as sheaves, mounted on a frame or housing. It is used to change the direction and/or magnitude of the applied force in a system of ropes or cables. The pulley block is typically designed with a groove or channel on the outer circumference of each pulley, through which a rope or cable can pass. The rope or cable is looped around the pulley and can be manipulated to exert force or to transmit motion.
Pulley blocks are commonly employed in numerous applications, including industrial, construction, and transportation sectors. They are particularly advantageous in scenarios where heavy loads need to be lifted or moved with ease. The main purpose of a pulley block is to reduce the amount of force required to lift or move an object by distributing the load over multiple ropes or cables and increasing the mechanical advantage of the system. This can be achieved by using multiple pulleys in a block, each adding to the mechanical advantage.
Furthermore, pulley blocks can also be used to change the direction of force applied to the load. By incorporating additional pulleys in a block and carefully arranging the ropes or cables, the direction of force can be redirected, allowing for pulling or lifting in various angles or directions. Pulley blocks are efficient, reliable, and versatile devices that make complex or heavy lifting tasks more manageable and safe.
Etymology of PULLEY BLOCK
The word "pulley" is derived from the Old French word "poulie", which has roots in the Latin word "poliolium". This Latin term originally referred to the sheaves or rollers used in block and tackle systems. The word "block" in "pulley block" is believed to come from the Middle Dutch word "blocke", which means a wooden log or tree trunk. A "pulley block" is a combination of a pulley and a block, where a block refers to a housing or frame containing one or more pulleys. Over time, the words "pulley" and "block" merged to form the compound term "pulley block" to describe this mechanical device.
