How Chain Hoists Work?
What are the components of a Manual Chain Hoist?
A Manual chain hoist is a pretty simple device considering the large amount of weight such a tool can lift. Chain hoists are made from durable, high-grade steel to ensure safety and reliability when lifting a couple of tons. Manual chain hoists can be separated into three different part categories: lifting chains, lifting mechanism, and hooks.
Chain hoist has two chain loops – hand chain and lifting chain. Hand chain sits on a wheel located in the lifting mechanism, it needs to be pulled by hand in order to lift a load. The wheel inside the lifting mechanism has got special pockets that allow the hand chain to move the wheel. Lifting chain also loops the lifting mechanism and lifts or lowers a load. At the end of the chain, there is a grab hook, where you can attach lifting chains or slings, a load leveler or load itself.
There is also a hook on the top of the chain hoists housing. This hook is used to attach the hoist to a ceiling mount, trolley system or other construction that can withstand the weight a hoist will lift. Most chain hoists have swivel hooks, meaning that they can be turned 360 degrees around to allow for easier mounting.
The lifting mechanism consists of a cog, axle, driveshaft, gears, and sprockets. There is a chain brake on all Prowinch chain hoists that prevents the load from lowering when overloaded or unattended.
How manual chain hoist work?
The physics behind a chain hoist are very simple and have been used for lifting heavy objects for a long time. Chain hoist uses a mechanical advantage to transform small force over a long distance to large force over a short distance, this is possible by using multiple larger and smaller gears in the chain hoist mechanism.
To lift a load, chain hoist operator needs to pull down the hand chain, this turns the cog and axle which goes through the lifting mechanism. Inside the lifting mechanism are multiple gears which increase the mechanical work applied when pulling the hand chain for dozen times using gear ratio, allowing to easily lift loads with multiple ton capacities.
So, when the hand chain is pulled, the cog which is rotated by the hand chain turns the drive shaft and gears which turn the load chain sprocket, this also rotates the load chain that is looped over the load chain sprocket and lifts a load. Larger gears move slower than smaller gears but create more force, this is why chain hoist lifts load very slowly when compared to a hydraulic hoist. At the end of the lifting chain is a grab hook, which allows to easily attach and detach a load. Also, most chain hoist lifting mechanisms have a ratchet or braking system that prevents the load from slipping back but allows to lower a load by pulling the other side of the hand chain.
Manual chain hoist in comparison with other hoist types
Chain hoists have different uses, for example in construction sites, shops, warehouses, also in car service stations and other application, where precise lifting is required.
The disadvantages of manual chain hoists for engine lifting are:
• They are slower than other types of hoists.
• They have special requirements for installation areas, which limits places these hoists can be used, in opposite hydraulic hoists just need a solid and level ground.
However, there are also some advantages for using manual chain hoists for engine lifting:
• They don’t need electricity, oil or other additional resources to work.
• They are cheaper than electric or hydraulic hoists.
• They are simple to use and easy to repair and maintain.