Thread: Can anyone help me understand how this was done?...

I'm here in hope rather than expectation. We work with furniture and have found these flattened/canted springs inside a footstool. The footstool and associated sofas were produced in (West) Germany sometime in the early 80s. We need to recreate these for another project.

These flattened springs have started life as regular extension coil springs and then been flattened/rolled using an as of yet unknown piece of machinery or process. I've been in contact with around 20 different coil spring manufacturers around the world, none of whom can tell me how these were produced - so it's likely a two-step process has been used to turn regular coil springs in to these.

The spring wire diameter is approximately 2.0mm, and the outer diameter of the original coil looks be around 15mm. We believe they are made of stainless steel - but is there a way to confirm this - some sort of analysis that could be carried out to find the exact composition of the metal?
Does anyone have any idea which sort of machine or process could have produced these into this shape?


spring1 (1).jpgspring2 (1).jpgspring3profile (1).jpg

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Grahame

Simple, take a regular coil spring and squash it with some sideways movement along its length. As a proof of concept, I carefully took a hammer to the spring from a clicky pen and I'd call that pretty much the same.

IMG_20200506_195108.jpg

For mass production, I imagine that as a continuous spring comes off the coiling machine it might be guided through a pair of rollers to flatten it and then either wound onto a drum or cut to set lengths.

Some stainless steels are non-magnetic.
Some grades of stainless steel can be made into springs.
It may be that your samples are normal spring steel that has been electroplated - zinc, nickel?

Originally Posted by elanjacobs

Simple, take a regular coil spring and squash it with some sideways movement along its length. As a proof of concept, I carefully took a hammer to the spring from a clicky pen and I'd call that pretty much the same.

IMG_20200506_195108.jpg

For mass production, I imagine that as a continuous spring comes off the coiling machine it might be guided through a pair of rollers to flatten it and then either wound onto a drum or cut to set lengths.

Thanks for this - very helpful.

The profile height of the post-flattened springs are around 5.0mm, so with that in mind, what sort of rollers might produce this?

When I had a look quick online, I could only find rolling machines that allow sheets/metal up to around 2.0mm/3.0mm thickness - is this standard or would there be a machine that could roll them at around 5.0mm thick?

Originally Posted by nadroj

Some stainless steels are non-magnetic.
Some grades of stainless steel can be made into springs.
It may be that your samples are normal spring steel that has been electroplated - zinc, nickel?

Thanks - is there any way to find out the original spring metal compostion so we know what we need to ask for upon re-production?

Thickness is not an issue, there are machines that will roll 50mm, they're just bigger.

If you really need to know exactly what it is, look for material analysis companies near you, they will be able to test a sample of it and confirm but that seems like overkill. Why does the material have to match? Could you not just use whatever springs are made of today?

Originally Posted by elanjacobs

Thickness is not an issue, there are machines that will roll 50mm, they're just bigger.

If you really need to know exactly what it is, look for material analysis companies near you, they will be able to test a sample of it and confirm but that seems like overkill. Why does the material have to match? Could you not just use whatever springs are made of today?

Thanks again - is it a 'slip roller' I'll need or am looking for? Something like this: https://www.warco.co.uk/bending-roll...lip-rolls.html ?

If so, I can't seem to find anything online that has anything over 1.5mm capacity for mild steel (for sheet metal or otherwise).

Originally Posted by Signature

Thanks - is there any way to find out the original spring metal compostion so we know what we need to ask for upon re-production?

It will be made with spring wire, if you google your local spring manufacturers you should be able
to find one to make them for you.
As elan has said they are just a squashed coil.
The annealed wire would be formed into the coil and then flattened, most likely pressed between two plates, then they would be heat treated.

https://www.google.com.au/search?ei=...sclient=psy-ab

As said a rolling mill would do job the may have been hardened after flattening, how many do you need to produce, for a one off job a simple set of rollers could be fabricated

Apologies for my ignorance, but would you use a 'slip roller' like in the first attached picture, or a 'rolling mill' (second attached picture) for this sort of job?

s-l1600.jpg999_AXWA_12 (1).jpg

Could it be heat treated prior to going through something like this, which would perhaps help the rolling/flattening process?

Originally Posted by China

As said a rolling mill would do job the may have been hardened after flattening, how many do you need to produce, for a one off job a simple set of rollers could be fabricated

There's the potential that it might be something we produce regularly: 5.0mm thickness but up to 30 feet of eventual spring length a day.

no way will a roller flatten springs,

Originally Posted by shedhappens

no way will a roller flatten springs,

Why not? Might just need a larger roller

Originally Posted by elanjacobs

Why not? Might just need a larger roller

It will just press two coils apart and slip.