Hoists
A hoist is an apparatus designed to lift heavy loads. Hoists come in a variety of designs, but they generally consist of a chain or cord wrapped around a spool or drum wheel. The load is attached to the chain by a lifting hook, which rises and lowers as it is cranked. Hoists can be operated manually or with an electric, pneumonic, or hydraulic motor.
The line in a hoist can be made of several different materials, including rope, wire, cord, or chain. Each material offers advantages and disadvantages. Wire rope hoists, for instance, offer smooth lifting and are necessary for high-speed lifting. Chain hoists are more durable than rope. They are fairly simple and inexpensive, can withstand heat, and require a relatively low level of maintenance. Whatever line is chosen, routine lubrication is recommended to lower the frequency of replacement.
Hoists have been in use for over two centuries and are now prevalent in construction, industrial, and automotive work sites. Because of the wide array of products that can be transported using hoists, many different industries are able to benefit from these simple machines. Hoists can be found in many different settings, even in hospitals and care centers to help lift people with special needs.