Chain hoist

A chain hoist lifts the load on a round steel link chain. Through a gearbox the drive turns a chain wheel in whose pockets the links sit with positive engagement. The unloaded end of the chain runs into a chain container. A brake holds the load as soon as the drive stops, and an overload device – on electric chain hoists often a slipping clutch – prevents excessive loads from being lifted.

Because the chain is stored in a container rather than wound up, the possible height of lift depends only on chain length and container size. The load rises vertically without drifting sideways.

The distinction is by drive and by the number of chain falls.

The chain hoist is compact, robust and tolerates dirt better than a wire rope hoist. The chain is easy to inspect and replace. That makes it the standard hoist in the lower and medium capacity range.

Its limits lie in smoothness and speed. The chain runs over a wheel with few pockets, so the lifting movement is never entirely uniform. A push-button chain hoist is not meant for sensitive guiding by hand – that is what balancers, or chain hoists with handle control, are for.

The capacity covers the load and everything permanently hanging on the hook. Then come height of lift and lifting speed; for accurate setting down a slow creep speed is helpful. The mechanism group must match the duty: it expresses the running time and load spectrum the hoist is rated for.

Finally the environment – dust, moisture, temperature, explosive atmosphere – and the suspension: fixed with hook or eye, or on a trolley running on a beam.

The chain must be lubricated; chains running dry wear much faster at the link contact points. Side pulling is not permitted unless the manufacturer expressly allows it: chain guide and chain wheel are built for a vertical pull.

Inspection is periodic, as a rule at least once a year. The chain is measured for elongation, wear and damage and replaced when it reaches its discard criteria.