Simple machines are devices that change the magnitude or direction of a force. They use leverage or mechanical advantage to multiply force and usually have few or no moving parts. They work by applying a single force to do work against a single load force. The output force is increased, but the distance moved by the load is decreased. The ratio of the output force to the applied force is known as the mechanical advantage.
We have six different types of simple machines, and each imposes its own unique applications. Lever, pulley, wheel and axle, wedge, screw and inclined plane are the fundamental types of simple machines. Each tool has a vastly different structure and functionality relative to one another. Among this set, the pulley is one of the most used simple machines. Now let’s go deeper into some best applications of pulleys in our daily lives.
Important Application of Pulleys
A pulley is a wheel that sits on an axle or shaft and is used to support the movement of a tight rope, belt or cable and change its direction or to transfer power from one point to another. When a pulley is attached to a frame or shell and not used to transfer power to a shaft but instead is used to guide a rope or cable or exert force, the frame or shell is called a block. In such cases, the pulley is also known as a sheave or pulley wheel.
A pulley mechanism uses a rope with one end attached to a load and the other end used to apply force to lift or lower the load. The name pulley suggests this simple machine system is meant to make the pulling or lifting of objects effortless. Historically, pulleys were mainly used for heavy liftings, such as raising water in a bucket. Currently, pulley systems have a multitude of uses in both everyday life and commercial settings.
A common application of pulley mechanisms in engineering is their use in elevators or lifts. Elevators use high-tensile ropes, which help move them up and down based on user inputs. Without a pulley, a lift would require the use of heavy motors to pull the cables, making the lift mechanism more complex. Pulley mechanisms play a crucial role in the engineering of elevators, making it a common and recognisable application.
A pulley is used to raise water from a well, as it facilitates the task by changing the direction of force and multiplying it. Wells is one of the oldest examples of pulley usage. In order to extract water from a well, the bucket’s handle is tied to one end of the rope and is lowered into the well; the other end of the rope is held by the user, who applies force to pull it up. The pulley’s movable axle helps to reduce the effort required to lift a bucket of water from the well.
Raising a flag on a tall pole can be a physically demanding task, but using a pulley system with a rope can make it simple and effortless. The flag is attached to a rope that runs through the pulley, and then the user pulls it by the rope. The pulley wheel mechanism help to guide the rope and makes the flag move up the pole.
Manually operating a garage door can be difficult due to its weight and size. In order to ease this process, pulleys are installed on the top corners of the garage door, connected with a light string that allows the door to move up and down smoothly. The motor activates the door’s movement, using a torsion spring system or extension springs to balance the weight of the door, thus enabling secure and steady movement.