6 Different Types of Pulleys (And When to Use Them)
Pulley systems have been around since the dawn of humanity, and are among the six simple machines we use to accomplish tasks. The first pulley or at least the first recorded pulley dates back to between 287 – 212 BC. The Mesopotamians used this pulley system to hoist water up for various uses.
Fast forward a few hundred years later, and different types of pulleys are still prevalent in industries, workshops, and homes across the country. The only difference between these pulleys is that they are much more efficient and mechanized than they were before. So the pulleys that we have today can lift much larger loads and are easier to use than the first pulleys.
In this post, we’ll be highlighting the most common types of pulley systems that you should consider for your particular needs. That way, you can make the right pick the next time you’re out pulley-shopping.
1. Fixed Pulleys
Fixed pulleys are the most common type of pulleys, and the most simple, for that matter. As the name suggests, the pulley stays in a fixed position throughout its use. You typically fix this pulley to a wall, ceiling, or any other stationary platform. That means that once you install this pulley, it stays there permanently unless you remove it and install it elsewhere.
With fixed pulleys, the amount of pressure or force you apply on the pulling side is the amount of that it will exert on the lifting side. With absolutely zero-efficiency, most people wonder why anybody would want to buy a fixed pulley system. However, a fixed pulley system is mostly for changing lift or pull direction in a large network of pulleys.
So although it has absolutely no efficiency, it’s very necessary for most industries and workshops. If you only need one pulley for your tasks, then buying a fixed pulley for the job would be very unwise. However, these types of pulleys are great for flagpoles and curtains
2. Moveable Pulleys
Moveable pulleys are the exact opposite of fixed pulleys. That’s because unlike fixed pulleys, moveable pulleys can actually move from their position. This makes them ideal for various applications and a staple for a lot of industries.
Moveable pulls actually move with the load, so the force you use to pull the pulley multiplies on the lifting side. You attach these pulleys to the object that you’re going to lift and detach it once you’re done lifting it. That means you can’t change the direction of the object that you lift.
Due to its efficiency, this type of pulley is ideal for lifting very heavy objects. You can thus find these pulleys in cranes for construction and utility elevators. They are also used in various industries for heavy lifting.
3. Compound Pulleys
You get a compound pulley when you combine a fixed pulley with a movable pulley. These types of pulleys put together the usefulness of fixed and moveable pulleys in a single system. That means the fixed pulley can change direction, and the moveable pulley can multiply the pulling force.
You attach the object on the movable pulley, while the moveable pulley attaches to the fixed pulleys using a rope. These types have an added advantage over other pulley types because you can change both the direction of the pull and the lifting.
4. Block and Tackle Pulleys
The block and tackle pulley is a special type of pulley, which greatly reduces the amount of pulling effort. This is not a fixed pulley, but an elaborate network of several pulleys, both fixed and movable. All the pulleys in the system are parallel to each other.
This parallel arrangement means that fixed pulleys are parallel with other fixed pulleys in pairs, and moveable pulleys the same. Each compound pair, two fixed and moveable pulleys, pair joins other pairs to form a network of these pulleys.
You can trace back this pulley system to Archimedes, the famous inventor, and mathematician of ancient Greek. These types of pulleys are great for sailboats, car garages, and workshops where lifting heavy objects is the norm. They are also excellent for construction and boat lifts.
5. Conveyor Pulleys
Conveyor pulleys, as the name suggests, are pulleys for conveyor belts. These pulleys change the direction of the conveyor belt. You can find them at the end of conveyor belts.
They consist of locking assemblies and end disks that are flexible. They have no other application outside of changing direction in conveyor belts.
6. Cone Pulleys
Cone pulleys get the name “cone” because of their uncanny resemblance with a cone. The pulley consists of several pulley wheels stacked on top of each other, with the smallest one at the top. This makes the pulley system look like a cone.
This assembly of pulley wheels allows the operator to change the speed of the pulleys’ lift. Smaller wheels require less pulling force, but also produce lower lifting force. These pulleys work on the same principle that bikes with gears use.
Switching to the smaller gears makes it easier to pedal, but the bike only moves a small distance. While switching to the larger gears makes it harder to pedal, but the bike also moves a greater distance with each revolution. It’s great for places where there’s a frequent shift in work demand.
Whatever your choice of a pulley, always ensure that the pulley’s rope is made of rigid and robust materials. That’s because there are plenty of instances where ropes or pulley cables snapped, and none of them ended well. For pulleys that are strong and durable, always be on the lookout for mechanical cable pulleys to serve your purpose.
Find Different Types of Pulleys That Suit Your Needs
Clearly, there are many different types of pulleys, but you probably only need one type for your needs. A pulley is a huge investment, so when you get one, make sure it suits your needs completely. You can liaise with the experts to find out which type of pulley will work best for you.
Pulleys are a staple for the construction industry, especially in buildings with elaborate designs. There are lots you can learn about construction and design if you check out the other pieces on the site.