Chain Hoists

Chain hoists are used for lifting, moving, rotating, and maneuvering heavy objects. They are usually suspended from an overhead rail, crane, or fixture capable of withstanding the load being picked up.

Manual Chain Hoists:

     

Manual chain hoists have a lever or chain as the lifting mechanism which you turn or pull (respectively). They come with either a hook or trolley to suspend them.

Specs:

• ½ ton to 100 ton capacities available
• Compact design
• All-steel construction
• One-Handed operation (on lever models)
• Slip clutch prevents over loading  capacity (chain models)

Electric Chain Hoists:

           

Electric chain hoists are available in single phase or three phase power configurations. They come with either hook, manual trolley, or geared trolley suspension options.

Specs:

• 1/8 ton to 20 ton capacities
• Adjustable dual speed
• Completely sealed body for harsh conditions
• DC current motor brake with electrical fail safe design

Air Chain Hoists:

     

For when an electric power supply is not available. These hoists feature unlimited duty cycle for extreme applications.

Specs:

• 250 lbs. to 25 ton capacities
• Adjustable load limiter stops lift when load is over capacity
• Very fine feathering control allows precise load positioning

 

*Electric wire rope hoists are also available

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Mechanics of a chain hoist

• Thread starter

  g.bashyam

• Start date

  Jun 11, 2011

• Tags

  Chain Hoist Mechanics

In summary, a chain hoist is a force multiplier that uses gears and a chain to lift heavy loads. The number of teeth on the gears determines the mechanical advantage, with a larger gear resulting in a greater output distance for a given input distance. This can be expressed mathematically by the equation (T-t)/2, where T is the number of teeth on the larger gear and t is the number of teeth on the smaller gear.

• Jun 11, 2011

• #1

g.bashyam

3

0

Can anyone explain the mechanics of a chain hoist and its mechanical advantage, in mathematical terms,?
thank you
Bashyam

 

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• Jun 11, 2011

• #2

Quinzio

558

1

It's a force multiplier.
You look the number of turns of the chain and this number multiplies the original force.

 

• Jun 11, 2011

• #3

DickL

96

0

There are several different types of chain hoists. The most common type seen today has an input chain loop that drives the output (lifting) chain via a step down gear unit inside the hoist's housing. I think the gear unit is a planetary one.

 

• Jun 14, 2011

• #4

JohnMorriss

2

0

The simpest form of chain hoist consists of a pair of discs of different diameters, locked together with their centres aligned. The two gears on the pedal crank of a ten-speed bike are what you should picture. The gear "teeth" are designed to mate without any chance of slipping with the chain being used.

The chain comes from somewhere, pases over one of the gears from (say) left to right, drops down and around an idler wheel. From there it goes up and over the SECOND gear, again from left to right, and then goes off somewhere. The cheapest way is to connect the two "somewhere" ends of the chain together.

Suppose the larger gear as T teeth, and the smaller has t teeth. If you pull in enough chain to rotate the paired gears 1 revolution clockwise, then you have removed T links of chain from the hanging loop, and added t links feeding off the smaller gear into the loop. So the loop gets shorter by ( T - t ) links, and since the loop goes down to the idler and then back up, the idler rises by ( T - t ) / 2 links.

So you exert a force through a distance of T links, and get an output through ( T - t ) / 2 links.

If the two gears have 24 and 20 teeth, for example, you pull in 24 links of chain to raise the load 2 links. 1 / 12 the distance means 12 times the force

 

Last edited: Jun 14, 2011

• Jun 20, 2011

• #5

PJC01

1,503

0

Sure, I'd be happy to explain the mechanics of a chain hoist. A chain hoist is a type of lifting device that uses a chain and pulley system to lift and lower heavy objects. The basic components of a chain hoist include a lifting hook, a chain, a pulley, and a hand chain or lever for operating the hoist.

The mechanical advantage of a chain hoist refers to the ratio of the load lifted to the force applied. In other words, it is a measure of how much easier it is to lift a heavy object using a chain hoist compared to lifting it by hand. The mechanical advantage can be calculated using the following formula:

Mechanical Advantage = Load / Effort

Where:
- Load refers to the weight of the object being lifted
- Effort refers to the force applied to the hand chain or lever to lift the load

For example, if the load being lifted is 1000 pounds and the effort applied to the hand chain is 100 pounds, then the mechanical advantage of the chain hoist would be 1000/100 = 10. This means that the hoist is able to lift the load 10 times easier than lifting it by hand.

The mechanical advantage of a chain hoist can also be affected by the number and arrangement of pulleys in the hoist. The more pulleys, the greater the mechanical advantage. This is because each pulley reduces the amount of effort needed to lift the load.

In addition to the mechanical advantage, the chain hoist also utilizes the principles of leverage and tension to lift heavy objects. As the hand chain or lever is pulled, tension is created in the chain, which is then transferred to the pulley and ultimately to the load. This tension, along with the mechanical advantage, allows the hoist to lift heavy objects with relatively little effort.

I hope this explanation helps to clarify the mechanics of a chain hoist and the concept of mechanical advantage. Please let me know if you have any further questions.

 

1. What is a chain hoist?

A chain hoist is a device used to lift and move heavy objects. It consists of a chain, a pulley system, and a hook or clamp at the end of the chain to attach to the load. It is commonly used in construction, manufacturing, and other industries for lifting and positioning materials.

2. How does a chain hoist work?

A chain hoist works by using a hand-operated chain to pull the load upwards. As the chain is pulled, it goes through a series of pulleys, which increase the force applied to the load. This allows the user to lift much heavier objects than they could with just their own strength. The hoist also has a braking mechanism to prevent the load from dropping once it has been lifted.

3. What are the different types of chain hoists?

There are two main types of chain hoists: manual and electric. Manual chain hoists are operated by hand and require the user to pull the chain to lift the load. Electric chain hoists, on the other hand, are powered by electricity and have a motor that does the lifting. Electric hoists are typically used for heavier loads and are more efficient for repetitive lifting tasks.

4. How much weight can a chain hoist lift?

The weight capacity of a chain hoist can vary depending on the specific model and manufacturer. However, most chain hoists can lift anywhere from 500 pounds to several tons. It is important to check the weight capacity of a hoist before using it to ensure it can safely handle the load you are lifting.

5. What safety precautions should be taken when using a chain hoist?

Some important safety precautions to take when using a chain hoist include inspecting the hoist and its components before each use, ensuring the load is properly attached and balanced, and using proper lifting techniques. It is also important to follow the manufacturer's instructions and training on how to use the hoist properly. Additionally, always wear appropriate personal protective equipment and never exceed the weight capacity of the hoist.