Manual or electric chain hoists have existed for many years. They tend to carry smaller loads than wire rope hoists, but their convenience and ease of operation make them ubiquitous. Julian Champkin Check out the latest products.

The evolution of chain hoist manufacturing is constant, and different manufacturers target different market segments. Diverse rules and diversified products can only benefit consumers. The hard part is making choices.

Tiger Lifting owns the Quad Cam brake pawl design, which has been patented worldwide. This one-piece pawl design has been thoroughly tried and tested. "The system ensures that at least one of the two reciprocating cam pawls is permanently engaged. In case the pawl spring fails, this design will ensure that the brake can still work normally and bear the load without damaging the mechanism. No matter where the body is From any point of view, this allows the chain brake to operate safely," said Greg Fardell, business development manager.

Tiger has been manufacturing manual chains for more than 50 years. After several years of field trials, their latest development launched in 2020 is a new load limiter design. "It allows very accurate setting of load limits and the highest level of load and operator protection," Fardell said. When the bracelet of the manual lifting chain is pulled at a certain angle, the key is that it will not be twisted, jammed or jammed when it leaves and enters the handwheel. Tiger has a specially designed deep-profile chain handwheel to achieve this; it helps to pull the chain at any angle or direction up to 45 degrees, making the chain run smoother and faster.

The precise tolerance of the bottom hook yoke means that foreign objects are restricted from entering the load pulley area and the chain will not twist.

The multi-drop load pulley adopts DU self-lubricating metal polymer bearing. These unique composite materials include a steel backing for improved mechanical strength and a porous sintered bronze interlayer impregnated with PTFE and lead to achieve high wear resistance and extremely low friction. This makes them very suitable for subsea use.

Zero maintenance is possible because self-lubricating bearings can run completely dry, but lubrication will provide higher reliability under boundary conditions.

Tiger also has their patented "EZ Check" hook, which is used to check whether the hook is overloaded before. Three raised popular marks are embossed on the side of the hook to form an equilateral triangle. By simply measuring the length of all three sides to be the same, the inspection can show that the hook is still in its original state and that no overload deformation has occurred.

Not many crane manufacturing companies make their own chains. One of them is Kito. "This means that we can guarantee a consistent high quality from the hoist to the chain to the hook," said marketing manager David Rennert. "We have conducted extensive tests under extremely high stresses and analyzed all components in force flux. The requirements of our Kito standard far exceed the usual requirements in the industry."

Kito stated that it is one of the few manufacturers in the world that offers electroless nickel-plated load chains. "Compared with traditional load chains, these have higher corrosion resistance and lower wear," Rennart said. The chain strength is 800 to 1,000N/mm2. Another feature of this chain is that it reduces hydrogen embrittlement.

In Germany, Kito's CX and CB manual chain hoists and hand chain hoists, as well as their LX and LB hand lever hoists, have passed the DGUV-GS ("safety test") certification. "This is a certification established in Germany," Rennart said; "Kito is the only crane manufacturer to receive it."

For the Japanese market, Kito has an interesting concept: electric manual hoists. This is a high-capacity product based on a manual hoist design, used for loads that usually require two operators to lift. Using an electric manual hoist, one operator can complete this work.

The motor is connected to the main body of the hoist and controlled by a button pendant. The capacity ranges from 20t to 50t; the main difference between these hoists and traditional motors is that the body is more compact and the lifting speed is lower. "It is suitable for operations that require slight adjustments to the load position-setting beams or infrastructure components in place may be an example," Rennart said, "or doing heavy work in the manufacturing shop." It is called Kito MCB, Currently only available in Japan.

Kito's US subsidiary Harrington Hoists, Inc. also emphasizes the advantages of using its own chain. "Controlling the manufacture of hoists and chains to ensure the highest quality and safety for our users is essential," said Jason Said, director of business development. "The chain and the gourd are combined to form a complete machine."

"We provide manual chain hoists up to 100 tons. The higher capacity is achieved by adding mechanical advantages, and this is achieved through multiple reins, which of course involves more chains. As you would expect , A longer chain will increase weight, which must be considered in the hoist’s rated capacity. Therefore, if you can make a smaller and lighter chain, then you can have a lighter hoist packaging."

Harrington claims to produce the smallest and lightest chain hoist in the world, and its 0.5 ton CX005 mini chain hoist proves the lighter gourd packaging. This is the follow-up product of their 0.25 ton capacity CX003.

The CX series is equipped with a slip clutch as standard to ensure the safety of the operation and the operator. "User safety is our primary driving factor, so anything we do to reduce size and weight is a win-win situation," Said believes.

"The same goes for technological advancement. All of our manual chain hoists now use RFID technology, as this is becoming more and more important in the rigging community. Ease of maintenance is always the primary consideration in designing any new hoist. We do it for us Cranes is proud to provide this, maximizing ownership and return on investment for our customers."

In October 2019, SWF launched the latest generation of chain hoist Athlo chain. The first model in the series can be used for loads up to 2.5 tons; in the near future, the production capacity will reach 5.0 tons. The design has a brand new internal structure and brand new mechanical parts.

The 4:1 ratio of the new two-speed motor and the redesigned heat sink provide better cooling and extend the life of the hoist. It has a redesigned limit switch, and it can also be used as an end-of-operation switch, whether in daily use or under extreme conditions. The chain bag is new, and the brakes are also new, designed to last 1 million cycles or up to a lifetime when handled correctly; it will respond immediately when the power is turned off. The slip clutch has a larger diameter and additional grooves, once again improving the cooling effect of the gear oil and increasing the overall service life.

The compact design and the new upper eye suspension increase the lifting height under the same suspension height. With the new suspension bracket, special safety pins can be used to install carts or electric carts. No other tools are needed. They said that high security, performance and availability, easy maintenance and long service life are the factors driving the development of the Athlo chain.

Columbus McKinnon's most innovative chain hoist product is Lodestar VS. Its electric motor has a variable frequency drive: a single-phase model was just launched in March of this year. The main feature of VS is CM's HI-Tech lifting interface technology.

With this, the operator can plug the hoist into a computer or tablet via a USB port; from there he can access performance information and change any parameters he wants. Maximum, minimum and even average speed, acceleration and deceleration can be set. The interface also provides a built-in error prevention function, which can reject incorrect parameters and prompt the operator to make corrections before the programming is complete. According to the control mode and speed selection, the acceleration and deceleration rate is automatically calculated; it can display the status information of the hoist, including the start/stop cycle, motor running time, current temperature, and over-temperature and over-current events. It also displays hoist fault information. Columbus McKinnon says it is one of the easiest computer interfaces on the market.

William Hackett is another company that uses its chain advantages to incorporate expertise into its crane range. Their cranes are unusual because they can be safely lifted from any angle. “Lifting at a certain angle brings risks that are often underestimated,” said supervisor Ben Burgess. Fleeting, also known as cross traction or snigging, is the practice of moving the load laterally by supporting the load from two or more fixed cranes and adjusting the chain length of each crane in turn, so that the load is gradually transferred from the vertical direction under the right-hand hoist To the vertical bottom of the left-hand winch. This is usually done, but there is a special risk: when the hoist pulls the vertical line at an angle, its work load limit (WWL) may be much smaller than normal. So it needs to be downgraded.

The hoist manufacturer gives derating values ​​at different angles from the vertical; these values ​​are specific to each brand of hoist. Users usually don't know these, if they know, using them will increase the complexity of the upgrade plan, so the time required to prepare it and the associated degree of risk. "Check the manual," Burgess said. "Unless it says that the hoist is safe to use at a certain angle, it is not safe: don't do it. If in doubt, please ask the manufacturer for clarification." The unusual thing about William Hackett cranes is that they are at an angle. No derating is required up to 45°; they are as strong at an angle as vertical.

On the surface, the chain hoist is a simple and mature technology. This seems to mean that fundamental improvements are rare. However, William Hackett designed such an improvement. As one might expect, their SS-L5 QP manual lever hoist has useful design features: First of all, it is light in weight.

"I was recently talking to the head of a global oil company," Burgess said. "He told me that statistics show that 80% of hoist-related injuries do not occur when the hoist is used, but in the logistics stage, when it is moved into place. The crane moves from the truck to the warehouse shelf, and from there Move to the pallet, from the pallet to the back of the truck. People do these things manually, and this is where the accident happened. He said that when it comes to investigating and paying investigators, the average cost of injury is 20,000 euros— —This applies whether it is a toe fracture or a back strain. Therefore, compared with heavier cranes, light cranes have a huge advantage: the possibility of injury is much smaller.

"This in turn means that people should use different criteria when choosing a crane. Rather than just looking at the lifting capacity, it is better to look at its performance ratio: the ratio of its capacity to weight. Our new SS-L5 QP lifts 1.6 tons, It weighs only 8.5 kg. Divided in two, you will find that it can lift 188 times its own weight. This is its performance ratio, which is a huge benefit for users."

But the most radical features of L5 QP are elsewhere. It is the first lever hoist with four-jaw mechanical engagement. The pawl is an object that meshes with the ratchet gear and prevents rotation to fix the load.

Spring-loaded pawls and ratchets have long been used in lever hoists. If the springs fail, they can easily fail: the load will suddenly drop at a high speed. Therefore, as a safety feature, the double pawl has been the industry standard for a long time, and it is said to be twice as safe. If one pawl fails, the other pawl will hold the load.

However, Burgess said that in the fine tolerance increase, unless the double pawls are offset, they may enter an unstable state. There is a bit of load on the tip of the ratchet teeth, which provides any ratchet that may be engaged for the ratchet to rotate too fast. claw. "According to our experience, pawls and pawl springs are spare parts that are frequently replaced. From this, we infer that they are prone to wear or failure," he said. William Hackett's four-claw system, he said, is resilient to mechanical failure. It is a patented design, simple but ingenious.

The four pawls are used as two pairs, and each pair shares a pawl holder. When the toothed ratchet rotates, one pawl rises to the ratchet teeth, interacts with its partner, pushes it down towards the ratchet and makes it mesh with the next tooth. The pawl is always engaged with the ratchet wheel, which has nothing to do with any spring action-although a spring is installed as an additional elastic measure to provide more failure redundancy.

"The pawl adopts an offset configuration for finer adjustment and tensioning capabilities. The pawl spring is completely enclosed in the brake chamber; no matter how impossible, the design allows two pawl springs to fail. Even in that In this case, the four pawls will still maintain full functional engagement with the ratchet gear. The result, of course, makes the crane safer," Burgess said.

Last year, Ohio crane manufacturer David Round celebrated their 150th anniversary. One of the company's specialties is low headroom cranes, which can be as low as 13.5 inches (34 cm) on cranes that lift 10,000 pounds (4.5 tons). Another specialty is the gourd made of stainless steel. "There are some cranes on the market that use some stainless steel or aluminum parts; but we are the only manufacturer in the United States that uses stainless steel to make hoists," said Matt Downing, director of sales and marketing. The company has just launched a new design that combines these two functions: a low-headroom stainless steel gourd for the pharmaceutical and food industries, which Tangning said is the smallest headroom available in any gourd design on the market. "They are made to order (like all our stainless steel hoists) to meet the requirements and specifications of each customer."

He said that one of the great advantages of stainless steel is its cleanability. "Stainless steel gourds are easy to clean. This especially provides us with a very large market in the food and pharmaceutical industries.

Usually, these cranes are thoroughly flushed every night. We can provide clean room products without solder marks and other surface defects.

"Another advantage of the all-stainless steel structure is spark protection. When hazardous environments require it, we can provide explosion-proof versions of stainless steel chains, wire ropes and belt hoists."

"Our explosion-proof hoist has a NEMA 7 housing and accessories, intrinsically safe button pendants, and the required explosion-proof motors. Except for stainless steel hand push wheels, load chains, bottom blocks and hooks, each is equipped with rubber buffers.

"We are currently studying stainless steel hoists with a capacity of 3 tons and 5 tons, and we will provide them as a new production line."

JD Neuhaus (JDN) will launch a food-grade version of its mini pneumatic hoist series this month (April 2020) to meet the cleanliness and hygiene requirements of the food, chemical and pharmaceutical industries. The motor housing is made of uncoated cast aluminum. The chain, chain guide plate, load sleeve and hook are all made of stainless steel. This makes the hoist corrosion resistant and not affected by high humidity. The hoist is easy to clean: even high-pressure cleaners can be used on them without any problems. The use of compressed air as an energy medium means that no electrical short circuit occurs, and the hoist can be used in areas containing flammable organic substances, etc. A completely synthetic, mineral oil-free special grease does not cause physiological risks. It is used to lubricate motors and is especially suitable for the food and pharmaceutical industries. The lubricant of the chain has also obtained food grade certification. The top hook and load hook of the hoist have twist locks to ensure safety. The lifting height of the hoist is 5m, and the control length is 4m.

The corrosion-resistant chain is also the hallmark of Ingersoll Rand's KMX Kinetic series of manual hoists. These gourds have copper-plated fireproof hooks; they are ATEX certified and can operate in potentially explosive atmospheres. The hoist itself is an all-steel structure; the VH load chain has a high-quality inorganic zinc coating, which can provide excellent corrosion resistance in harsh and humid outdoor environments while minimizing downtime. Fasteners and bracelets are made of stainless steel to prevent rust. Dip spin and powder coating on key components can increase corrosion resistance. The capacity ranges from 0.5 to 20 tons. Ingersoll Rand Global Product Manager Brad Imhoff (Brad Imhoff) said: "Sparks and corrosion-resistant materials reduce the need for expensive equipment and parts repairs that are often required after repeated exposure to harsh environments." Extreme environmental tests have shown that after hundreds of hours of salt spray exposure, the corrosion of this series of products has been significantly reduced."

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