Overview of hoist

A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. It may be manually operated, electrically or pneumatically driven and may use chain, fiber or wire rope as its lifting medium. The load is attached to the hoist by means of a lifting hook.

Types of Hoist:

The basic hoist has two important characteristics to define it: Lifting medium and power type.

The lifting medium is either wire rope, wrapped around a drum, or load-chain, raised by a pulley with a special profile to engage the chain. The power type can be either electric motor or air motor.

Both the wire rope hoist and chain hoist have been in common use since the 1800s. A hoist can be built as one integral-package unit, designed for cost-effective purchasing and moderate use, or it can be built as a built-up custom unit, designed for durability and performance. The built-up hoist will be much more expensive, but will also be easier to repair and more durable.

Package units are designed for light to moderate usage, while built-up units are designed for heavy to severe service. A machine shop or fabricating shop will use an integral-package hoist, while a Steel Mill or NASA would use a built-up unit to meet durabilty, performance, and repairability requirements.

Construction hoists:

Also known as a Man-Lift, or construction elevator, this type of hoist is commonly used on large scale construction projects, such as high-rise buildings or major hospitals. The purpose being to carry personnel and materials quickly between the ground and higher floors, or between upper floors.

The construction hoist is made up of either one or two metallic cages which travel vertically along stacked mast tower sections. For controlled travel along the mast sections, most modern construction hoists utilize a motorized rack-and-pinion system mounted onto the mast sections, while some older hoists still utilize a system of counterweights.