Hoists are tools used for lifting and lowering heavy loads. Hoists are frequently used in the construction field to lift pallets, wagons, and other heavy loads. The term "hoist" derives from the French term "huis" (wide rope). A hoist is usually a piece of metal that is used for raising or lowering an object using a drum, spring or other lifting device. In common usage, the term "hoist" refers to any type of lifting apparatus used in the lifting of objects. It can be manually operated, electronically operated or pneumatically driven.
Hoists can be classified according to the force they exert upon the object lifted. There are direct forced winches, alternating current powered winches and electromagnetic hoists. Direct forced winches use a wire rope to raise and lower objects whereas alternating current and electromagnetic winches are power operated and have no power source. Pneumatic, electric and air powered hoists are some of the various types available.
All types of hoists can be divided further into two broad categories according to the force they exert. First, the strength of the motor driving the hoist and second, the capacity of the hoist to exert that force. Most typically, a motor is placed in a vertical position, directly in front of the hoist. However, in some cases, such as for wire rope duty cycle rated winches, the motor is positioned on a horizontal platform in the proximity of the hoist. In this case, the distance between the hoist and the motor is variable.
In addition, there are also separate components that combine the function of both the hoists and the lifting weights. The most common of these components are winches and wire rope duty cycle units. Other components are usually present on both the hoists and the wire rope duty cycle units. Examples of such components are: drive rollers, drive chains, locking levers and ratchets.
While wire rope hoists have long been a standard in the industry of lifting, there have been many advancements in the types of hoists available. First, there were wire rope pulley hoists, which are similar to wire rope winches in that they use a wheel to raise and lower the load. Next, there were cable hoists and screw hoists. Both of these types of hoists are operated using a chain, a series of gears or a pinion to allow the hoist to lift a heavier load than wire rope hoists.
There are now so many types of hoists available in the market that choosing one may require a bit of homework. For instance, if the job site requires a heavier load to be lifted, then the cable hoists will be your best choice since they can lift up to 400 pounds. However, cable hoists are limited by the capacity of the wire rope duty cycle motor. Likewise, if the lifting requirement is low, then the screw hoists or wire rope units will be your best options since they can lift much lesser weights. As mentioned, before buying any type of hoist, you should also know how the hoist will work and how will it lift the load that you need to lift. Find out more about lifting large objects!
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