Chain hoists, manual or powered, have been around for many years

 Tiger Lifting has its globally patented Quad Cam brake pawl design. This single piece pawl design is thoroughly tried and tested. “This system guarantees permanent engagement of at least one of the two reciprocating cam pawls and in the unlikely event of a pawl spring failure, this design will ensure the brake is still fully functional and the load is sustained without damage to the mechanism. This allows the chain block brake to function safely no matter at what angle the body is positioned,” says business development manager Greg Fardell.

Tiger have been making manual chain blocks for more than 50 years. Their latest evolution, introduced in 2020 after several years of field trials, is a new design of load limiter. “It allows very accurate setting of the load limit and the highest level of load and operator protection,” says Fardell. When the hand chain of a manual hoist chain is pulled at an angle, it is critical that it leaves and enters the hand wheel without twisting, snagging or jamming. Tiger has a specially designed deep-profile chain block hand wheel to achieve this; it helps to seat the chain at any angle or direction of pull, up to 45 degrees, allowing the chain to run more smoothly and quickly.

Precise tolerances in the bottom hook yokes mean that foreign objects are restricted from entering the load sheave area and the chain cannot get twisted.

The multi-fall load sheaves incorporate DU self-lubricating metal polymer bearings. These unique composites comprise a steel backing for mechanical strength and a porous sintered bronze interlayer impregnated with PTFE and lead for high wear resistance and extremely low friction. This makes them ideally suited to subsea use.

Zero maintenance is possible, as selflubricating bearings can operate perfectly dry, but lubrication will give greater reliability under boundary conditions.

Tiger also have their patented ‘EZ Check’ hooks to check that the hook has not been previously overloaded. Three raised pop marks are embossed on the side of the hook, making an equilateral triangle. By simply measuring that all three sides are the same length, an inspection can show that the hook is still in its original state and no distortion from overloading has occurred.

Kito

Not many hoist-making companies make their own chain. One that does is Kito. “That means we can guarantee consistently high quality from the hoist to the chain to the load hook,” says marketing manager David Rennert. “We carry out extensive testing at extremely high stresses with analysis of all parts that lie in the flux of force. The requirements of our Kito standard are far beyond those that are usual in the industry.”

Kito says it is one of the few manufacturers worldwide to offer electroless nickel-plated load chains. “These give higher corrosion-resistance and lower wear than traditional load chains,” says Rennert. Chain strengths are 800 to 1,000N/mm2. Another characteristic of the chain is reduced hydrogen embrittlement.

In Germany, Kito’s CX and CB manual chain hoists and hand chain blocks, as well as their LX and LB lever hoists, are all DGUV-GS (“safety tested”) certified. “This is a certification established in Germany,” says Rennert; “Kito is the only hoist manufacturer to receive it.”

For the Japanese market Kito have an interesting concept: the motorised manual hoist. This is a high-capacity product based on manual hoist designs for loads that that would normally take two operators to lift. With a motorised manual hoist, one operator can do the job.

The motors are attached to the hoist body and controlled by push-button pendant. Capacities range from 20t to 50t; and the main difference between these hoists and conventional electric machines is that the body is much more compact and the hoisting speeds much lower. “It suits operations that require slight and minor adjustments to load positions—setting a beam or infrastructure component into place might be an example,” says Rennert, “or for heavy duty work on a manufacturing floor.” Known as the Kito MCB, it is currently available only in Japan.

Harrington Hoists

Kito’s US subsidiary Harrington Hoists, Inc. also stresses the advantages of using its own chain. “It is crucial to control the manufacturing of both the hoist and the chain to ensure the highest quality and safety for our users,” says Jason Said, director of business development. “Chain and hoist marry together to form the complete machine.”

“We provide manual chain hoists up to 100t. Higher capacities are achieved through increased mechanical advantage, and this is attained through multiple reevings, which of course involves more chain. As you would expect, the greater length of chain adds weight that must be accounted for in the rated capacity of the hoist. Therefore, if you can manufacture smaller, lighter weight, chain, then you can have a lighter hoist package.”

The lighter hoist package is evidenced in Harrington’s claim to produce the smallest, most lightweight chain hoist in the world, in their 0.5t CX005 mini hand chain hoist. It is a follow-up to their 0.25t-capacity CX003.

A slip clutch is fitted as standard to the CX series, to ensure the safety of operation operations and the operator. “User safety is our number one driver, so anything we can do to reduce size and weight is a win/win,” is Said’s view.

“The same is true of technological advancements. We now have RFID technology on all our manual chain hoists, as this is becoming much more relevant in the rigging community. Ease of maintenance is always a leading consideration in designing any new hoist. We pride ourselves that our hoists offer this, to maximise the benefits of ownership and return on investment for our clients.”

Chain hoists, manual or powered, have been around for many years