Pulley: meaning, definitions and examples

A pulley is generally used when referring to a single wheel on an axle or shaft that is designed to support movement and change of direction of a taut cable or belt, or transfer of power between the shaft and cable or belt. It's common in simple machines and everyday lifting tasks.

• The pulley system helped lift the heavy furniture to the second floor.
• I used a pulley to hang the bicycle in the garage.

This term is used when referring to a system of two or more pulleys with a rope or cable threaded between them, usually used to lift or move heavy objects with greater mechanical advantage. It is commonly used in sailing, construction, and theater.

• The sailors used a block and tackle to raise the sail.
• In the construction site, they employed a block and tackle to move the steel beams.

A hoist is typically a device used for lifting or lowering a load by means of a drum or lift-wheel around which a rope or chain wraps. Hoists can be manually operated, electrically or pneumatically driven and may use chains, fiber or wire ropes as its lifting medium. It's common in industrial and construction settings.

• The workers used an electric hoist to lift the machinery onto the truck.
• They installed a hoist in the workshop for lifting heavy parts.

A sheave is specifically the grooved wheel or pulley that a rope or cable runs over. It's a more technical term often used in mechanical and engineering contexts, not typically in everyday conversations.

• The sheave in the pulley system needed to be lubricated to reduce friction.
• The engineer inspected the sheave for any signs of wear.