Hoists - Manual or Powered?
Electric powered hoists and manual hoists are compared inside this publication. Their uses, pros and con’s and properties will also be discussed.
The wide range of hoisting devices available means that there is one to suit most tasks. They are used by a lot of industries including forestry and farming, dock yards, production plants, car industries and construction sites, to name but a few. In many cases hoists are normally used because the load is just too big or heavy for an individual or persons to pick up, or because it would be too dangerous. Another reason for hoists to be used is to hurry up the lifting and manoeuvring process and so is often cost efficient.
Allow us to now look at the varied kinds of hoisting machines. First of all the powered type; you can find the electric hoists, which are obviously driven by electrical power and the air hoists, that are powered by pneumatic air.
You will find two key types of hoisting equipment which are driven; these are the electric hoist and also the air hoist. Air hoists are typically used where electricity cannot, or is not accessible. The air hoist will however need a pneumatic air supply to function. Often used in car garages, oil industries, paper mills and other industries wherever electrical power can be a fire hazard. Air hoists may be more economical where lots of air tools are used at the same time, since it is less costly to operate 20 air powered tools from 1 air compressor unit than it will be to run twenty electric hoists from twenty individual power sockets. Air hoists also have 100% duty rating; they are very tough and have a very lengthy service life; they are simple to maintain thanks to only using air, but they will be limited to where they can be used seeing that they are permanently attached by hose to the air compressor.
Electric hoists are an extremely popular piece of lifting equipment; all it needs is an electric power source to operate. These hoisting devices are portable, unlike the air hoist; so can be utilised just about anywhere. Typically hung on a beam clamp or trolley on a jib crane or mobile gantry to facilitate even more movement; one simple push of a switch on the pendant remote control and you’re away; lifting becomes safer, simpler and quicker, and with many different lifting capacities available from a few hundred kg’s to many thousands of kg’s, there will be something available for the majority of purposes, as long as, of course there is a power supply.
Manual Hoisting equipment will be considered in greater detail next.
Manual chain hoists and lever hoists are the two most widespread hoisting machines where no power supply is necessary. Because of this they are suitable for the majority of areas and are effortless to move from one position to another. The manual chain hoist/chain block are generally noticed on mobile gantry cranes or jib cranes, but can be attached from a simple hook, as long as it is capable of taking the loads weight. It is by pulling the chain in a downwards action that raises the load, due to the chain passing over gears to give the power and holding the load in a certain position by the brake system. By pulling on the opposite chain the load will lower. There are special models of this kind of hoist which enable it to be used from any angle due to its 360 degree mechanism. Manual chain hoists will lift tremendously heavy objects, and also to a diversity of heights, depending on the length of chain.
Ratchet lever hoists are not just utilised to elevate objects but also to pull and tension, in virtually any position. A lever hoist works by cranking a handle/lever up and down, the chain moves across the ratchet and pawl arrangement to lift, pull or tension. The majority of ratchet lever hoists use a free chaining system, which makes it possible for the chain to be pulled out without restraint to the length needed to connect to the load. Ratchet lever hoists are perfect for exact placement in small spaces and designed for tie down operations. These hoists are frequently used for the placement of heavy equipment, tensioning utility power lines, pipe setting, down manholes, holding objects in position whilst work is carried out and even pulling up tree stumps. Countless industrial areas utilize lever hoists as do the forestry and garage industries.
To conclude, it is obvious to see that every one of the hoisting devices described have good benefits and most likely some drawbacks, but these will greatly depend on, not only where they are to be used, but additionally the type of application they will be used for. Evidently powered hoists require a power supply, which can be restrictive of where they may be used, and will have some operating costs although they do enable the task to be finished much quicker. The manual hoisting systems have no running costs, just a little maintenance from time to time; some manual hoists are capable of lifting, pulling and tensioning from any position. As no power supply is needed they can be utilised practically anywhere.
Source: Free Articles from ArticlesFactory.com
ABOUT THE AUTHOR
Author Nikki Dale works for the Lifting Gear Direct group which incorporates Lifting Hoists Direct and Wire Rope Direct. We have been supplying many types of lifting equipment to trade and industry for many years and our team are very knowledgeable and experienced where lifting gear products are concerned.