Hoists perform mechanical work because it allows a force to act on a body to move it at a certain distance.
The term hoist has its origin in the Greek word “polys” which means “a lot” or “abundant” and grass which refers to the act of “pulling” or “pulling”.
What’s the hoist for?
Hoists are used in industries, workshops or construction areas to load and unload heavy materials to be placed in transport trucks, ships or fixed spaces.
The hoist enables this task to be carried out without difficulty, quickly and efficiently.
Its capacity to lift loads can vary depending on the number of branches used. For this reason, it is pertinent to verify the load weight that will be lifted and determine the most appropriate lifting equipment to hoist and move the load.
In some rescue cases, hoists are used to lift injured people who have fallen into cracks or deep spaces.
Types of hoists
In the market for loading machinery, there are many types of hoists. It is important to know the types and their characteristics in order to know which one is best suited to the task to be accomplished with this type of machine.
The hoists or rigs can be typified according to:
- Their number of branches: These can be simple, when one of the pulleys has only one gullet; or when there are two or more gullets they are known as double.
- The way it multiplies the force: They can be factorial (the force is proportional to the number of pulleys), potential (corresponds to 2 elevated to the number of pulleys) or difference (depends on the difference in radii between the two pulleys that make it up).
- The branches material: They can be rope, cable or chain.
- Depending on the power applied: They can be manual, lever or electric.
Below are different types of hoists or hoists.
Electric hoist
This type is designed according to the same operating principles as the hand hoist. In this case, an electric control replaces the chain drive. The electric control of this hoist allows lifting and lowering objects quickly or slowly.
Manual hoist
The chain hoist is manually operated, and its compact and lightweight design allows a load capacity of up to 2 tons. This tool is ideal for vertical lifting of the load to be moved.
The manuals are made up of a pulley system that allows the heavy load to be lifted with less vertical effort. In this type of hoists, the power to lift objects comes from the person who uses this device. Installation is usually very simple.
Crane
Allows the horizontal and vertical movement of heavy weights with precision and safety. It is used in many industries for deposit, storage or material transfer.
The hoist crane has a double structure in which two auto motors act allowing the sliding and railing process production.
This type is operated from a remote cabin.
By car
Trolley hoists can be manual or electric. In addition to the vertical lifting, they allow the horizontal displacement of the load.
Precautions for using a Hoist
- Check the maximum load of the hoist and do not exceed it.
- Make sure chains and wire ropes are properly lubricated.
- Immediately replace any worn chain or wire rope. Label any defective chain or wire rope and keep it out of service.
- There are hoists that can be operated in different directions but even so, it is preferable to pull as straight as possible. Lateral traction increases wear and can even be dangerous.
- Follow the maintenance schedule recommended by the manufacturer.
- Make sure that there is no person around the load before lifting it.
- Avoid tilting the load as it may become unstable.
- Avoid lifting the load more than is really necessary.
- Do not leave suspended loads unattended.
