Chain accessories options... 1

[tinnguyen123]

Hello,

Does anyone know of something that's similar to a turnbuckle, but is use for a lifting chain...?

This is the closest I can come to, but it's not made for lifting.. [URL unfurl="true"]https://www.mcmaster.com/#2967T6[/url]

 

[RolMec]

Hello,

you might try RUD (no rel.):

http://www.rud.com/en/products/slin...type-tensioner-for-the-length-adjustment.html

Regards

Roland Heilmann
Lpz FRG

 

[SwinnyGG]

You're not going to find a lift-rated chain ratchet. You wouldn't want to use one for lifting anyways- your lift would be VERY slow.

What is the real problem you are trying to solve?

 

[tinnguyen123]

Thanks RolMec for your suggestion, but what jgKRI said is correct, I asked the RUD ppl already, its state on their catalog that those are not made for lifting.

@jgKRI, I'm using lifting chains to lift a counterweight. I'm just trying to adjust the chain without removing links. There's chain/rope/cable that will be attach, and they need to be able to adjust individually in order to balance the "platform".


On the side note, does anyone see any problem looping a wire cable around the end of the chain. I think it's easier to adjust a cable than a chain.

 

[SwinnyGG]

Is this a permanent installation that only needs to be balanced one time?

The only option I can see is standard shackles, removed and re-installed on the correct link to balance your lift.

 

[hendersdc]

Instead of adjusting the chain can you just adjust its mounting point height? You could use something like these clevis rod ends in combination with a threaded rod or nut to adjust the height and then pin the chain to it. It wouldn't be able to be adjusted under load though since you need to disconnect the chain.

 

[SwinnyGG]

Also, I didn't catch this earlier:

On the side note, does anyone see any problem looping a wire cable around the end of the chain. I think it's easier to adjust a cable than a chain.

If what you're referring to is looping steel wire rope through a chain link and then using something like a wire rope clip to anchor it back to itself.. you definitely DO NOT want to do that. The proper way would be to create an eye in the wire rope, with a thimble, and then use a shackle to attach to the chain.

 

[tinnguyen123]

Is this a permanent installation that only needs to be balanced one time?

The only option I can see is standard shackles, removed and re-installed on the correct link to balance your lift.

Its a one time balance, that's how I see it too.. I was hoping for something safe that's available..

Instead of adjusting the chain can you just adjust its mounting point height? You could use something like these clevis rod ends in combination with a threaded rod or nut to adjust the height and then pin the chain to it. It wouldn't be able to be adjusted under load though since you need to disconnect the chain.

Our company has been using this setup for years, but it's always been done on a smaller scale and the adjustment were already difficult to do.. but now they're 5/8" size chains, so we have to make the mounting point insanely safe. The seniors engineers isn't too comfortable with threads, tension, and movements... The good thing is that this load will be moving a bit "slow".

However, I'm glad I'm not on the wrong page.

 

[Compositepro]

I recently saw a crane with a load adjuster between the load and the hook. It consisted of two short parallel chains with a rubber bladder between the chains.
Inflating the bladder pushed the chains apart, thus lifting the load slightly.

 

[tinnguyen123]

I recently saw a crane with a load adjuster between the load and the hook. It consisted of two short parallel chains with a rubber bladder between the chains.
Inflating the bladder pushed the chains apart, thus lifting the load slightly.

Do you happen to have a picture of it? I'm having a hard time picturing it..

 

[Compositepro]

I have not been able to find pictures. In principle anything that pushes two parallel chains apart at their midpoint will shorten the chains. The force will be a small fraction of the lifted load, but will increase as the chains are pushed further apart. Thus air pressure can control position very accurately.

The actuator was

http://firestoneip.com/-/media/

http://www/fsip/files/ManufacturingIndustrial/Advantages/Airstroke_Advantages_EN.pdf.