Electric Hoists

An electric hoist can offer a load carrying capacity for companies and individuals, which no human alone could match. They are used mostly for industrial applications within the automotive, mechanics, aerospace, construction, marine, engineering, manufacturing, agricultural and medical industries to safely lift heavy objects and move them to another location nearby. Some are designed to lift certain objects, like engine lifts and engine hoists or car hoists. The actual lifting is done by either a metal chain or wire rope, which are usually attached to a hook and wound around a large spool by a winch. Cable hoists, also known as wire rope hoists, use a configuration of wire strands wound around a rubber core that can handle a great amount of weight. Chain hoists, on the other hand, use roller or link chains as the lifting medium. Both types are much more durable than standard rope. Electric hoists come in two main configurations-portable stand alone or overhead. Overhead hoists are mounted on a ceiling or beam, while portable hoists usually have wheels, a metal rail configuration, are lightweight and easily transported.

The most important specification when lifting objects with a hoist is its maximum weight capacity-the object being raised must not exceed the weight requirements. If it does, worker safety is compromised and the hoist could drop the load, separate from its mounting or tumble over on its side. The actual lifting is done with either a metal chain or wire rope, which is composed of several metal wires wound around a rubber core. These components are attached to a large hook. Often, the load being lifted must have a hoist sling attached around it in order to be lifted in a balanced manor. The hoist or lift also has limited lifting length, which is dependent on the amount of chain or cable is provided on the spool. The lifting medium is wound many times and housed inside a metal casing. While some hoists are manually cranked, most use a mechanical winch that automatically winds the lifting medium with the pull of a lever or push of a button. The basic hoist is composed of a gear box, which contains the controls, a braking system, the casing for the wound lifting medium, and a large hook that attaches itself to a harness or the actual object being moved.

Because of the wide variety of materials and products that can be transported using electric hoists, winches and cranes, many different industries are able to benefit from these machines. An electric hoist can be used to move and handle large rolls of paper to install in printing presses, so that newspapers can be printed daily. In the food industry, electric hoists are capable of moving large equipment that is used for the mixing of ingredients and containers for storage. Electric hoists of this type are generally made for the particular environment and can be very gentle, depending on need. In mining applications, electric hoists are especially useful for withdrawing shield support and mounting platforms from mines. These electric hoists tend to be highly durable hoists that are able to withstand the rough environment, plus they tend to be explosion proof.

A common type of electric hoist is a chain electric hoist, which uses a linked or roller chain to lift and lower loads. Chain electric hoists are sturdy and can be advantageous because they are fairly inexpensive, simple to operate, generally rust-resistant and low maintenance. Additionally, these electric hoists are flexible and have the ability to withstand high temperatures and other less desirable environments. An alternative to a chain hoist is a wire rope hoist, which uses wire rope instead of chains to transport materials. These types of electric hoists can be used in various positions, either stationary or as a mobile unit attached to a trolley system. Other types of electric hoists are available for very specific applications, such as those used to remove engines from airplanes and automobiles, and those that help operate the gates of dams.

Before buying an electric hoist for a facility or specific lifting job, it is important to consider the application for which it will be used, along with the many different specifications and options that exist among different hoists and lifts. Maximum weight capacity, maximum lift speed, line type and mounting type of the electric hoists need to be taken into account as well. These are important considerations because, for instance, buying a casual load lifting hoist to transport a boat would lead to many safety issues. Using a lighter load hoist would result in damage to the hoist and/or boat, not to mention the safety issues it would raise for the employees. Safety must be taken into account when using electric hoists to ensure that the weight of the objects being raised or lowered does not surpass the maximum load carrying capability. Injuries can happen when dealing with this kind of equipment, so one must understand how to safely operate these electric hoists machines before use in order to avoid harm.

Electric Hoist Types

• Auxiliary hoists are supplemental hoists that are used to handle light loads at a higher speed than the main hoist.
  
• Boat hoists are lifting units specially designed to raise and lower boats. Boat hoists are typically hydraulically or electrically powered and can lift up to 20,000 pounds.
  
• Chain hoists use roller or link chains as a lifting medium. Chain hoists are typically electrically powered, but can be manually and pneumatically operated as well.
  
• Engine hoists are lifting units designed to allow engine removal from automobiles, airplanes or boats. Engine hoists are typically hydraulically powered, but sometimes use an electrical motor.
  
• Gate hoists are exclusively used to lift the water controlling gates at dams.
  
• Hoists are devices used to lift heavy loads.
• Modular hoists have an integral drum, motor and gearbox, with no visible shaft couplings between them.
  
• Overhead hoists are attached to wall columns or ceilings.
• Trolley hoists are hoists suspended from a trolley. These hoists can be built into the trolley or connected to the trolley using a clevis or hook.
  
• Winch pulls heavy loads horizontally.
• Wire rope hoists use wire rope as a raising/lowering medium. A complete wire rope hoist consists of a rope storage drum, one or more motors, a gear box and a braking system; they can be mounted in a stationary position or along a monorail attached to a trolley that allows them to slide to different locations.