Here at H Brown, we use gantries, beam trolleys, cranes, slide systems, mat jacks, air skates and even a 40,000 lb. reach lift to rig industrial loads all over Louisiana. For other jobs that your company might want handle in-house, the simple overhead hoist might be the equipment of choice.
Whether it’s raising an elevator, relocating a petrochemical tank or adjusting sensitive electrical switchgear, overhead hoists come in a lot of different hoist configurations and designs. And that’s because the loads and the work environments can be quite different from one job to another. Let’s look at the variables in various overhead hoist equipment and methods.
First, overhead hoists are manual or powered.
- A hand chain (manual) hoist usually means the hoist is ratcheted, levered or hand cranked. It works when the operator pulls a welded link load chain or roller load chain that consists of a series of interwoven links that fit the hoist hand chain wheel (sprocket). As the operator pulls the chain, the hand chain wheel turns and transmits lifting power.
- Powered hoists are common for mechanics and machine shops and include hoists driven by electric, hydraulic or pneumatic motors. Powered hoists work via a control device suspended from the hoist or mounted in a remote radio-control transmitter. This device powers a motor, which in turn powers the hoist load chain sprocket or hoist drum to lift or lower the hoist load hook. Electric hoists easily plug into the nearest wall outlet, whereas pneumatic chain hoists are common for lifting heavy equipment in flammable, dusty or dirty environments.
Overhead hoists are usually hook-mounted, lug-mounted or trolley-mounted.
- Hook-mounted hoists are suspended from the clevis (a U-shaped or forked metal connector) or suspension pin of a trolley via a top hook on the crane hoist frame. They might also be suspended from a fixed device mounted on a beam or the permanently attached on-site (on the building itself, for example). These hoists typically use welded link load chains or roller load chains as the lifting medium.
- Lug mounted crane hoists can also be suspended from a beam or building structure. They may also be trolley-mounted. These hoists feature a lug mounting attached to the hoist frame.
- Trolley-mounted crane hoists are hook-mounted, clevis-mounted or lug-mounted crane hoists suspended from trolleys.
Hoists typically use chain (welded link load chain or roller load chain) or wire rope.
- Welded link load chain is made up of a series of interwoven formed and welded links. These links fit into the hoist load sprocket (a.k.a. “load wheel, load sheave, pocket wheel or lift wheel”), which transmits motion to the load chain. Welded link load chain is manufactured to meet specific dimension and material strength requirements for a particular hoist.
- Roller load chain is made up of alternately assembled roller links and pin links. The pins articulate inside bushings, whereas the rollers freely turn on the bushings. The links fit teeth of the hoist load sprocket roller load chain. Like welded link load chain, roller load chain must also meet specific requirements for specific hoists to ensure safe, reliable operation.
- Wire rope consists of a core, strands and The rope fits onto grooves on a hoist drum. Don’t use wire rope hoists on manually-operated crane equipment like a jib crane, small gantry crane or hand-push bridge crane, as it can become unseated from the grooved drum and create a safety hazard. It’s best to stay with electric chain hoists for hand-push traverse applications.
(Click to see safety via Shupper-Brickle Equipment Co.’s “do’s and don’t” for the safe operation of manual, electric and air-powered overhead hoists)
Hoist Manufacturers Institute (HMI) Hoist Duty Classifications
The Hoist Manufacturers Institute (HMI) developed hoisting equipment standards for hand chain hoists, ratchet lever hoists, trolleys, air chain hoist, air wire rope hoists, electric chain hoists, and electric wire. Their “hoist duty classifications” (below) will give you an idea of the duty cycle ratings for the various electric hoists.
H Brown can help you make your next hoist installation successful. We’ll work with you to make sure your hoist supplier understands your requirements, including the environment, capacity and duty cycle your facility needs. Or, if you need to move heavy equipment in tight or hard-to-access spacers, you can leave the rigging to us. Our hydraulic jacking systems have virtually no weight limit, and we can lift oilfield and electric utility equipment that weighs up to 1 million pounds. Get in touch with us today!