Different kinds of springs and other info
Jan 30, 2010 1:14 PM
Location: L.A. area
Joined: Jan 18, 2008
Points: 1161
http://en.wikipedia.org/wiki/Mattress

From the page above:

"Spring mattress core

The core of the mattress supports the sleeper’s body. Modern spring mattress cores, often called "innersprings," are made up of steel coil springs, or "coils."

The gauge of the coils is another factor which determines firmness and support. Coils are measured in quarter increments. The lower the number, the thicker the spring. In general, higher-quality mattress coils have a 14-gauge (1.63 mm) diameter. Coils of 14 to 15.5-gauge (1.63 to 1.37 mm) give more easily under pressure, while a 12.5-gauge (1.94 mm) coil, the thickest typically available, feels quite firm.

Connections between the coils help the mattress retain its shape. Most coils are connected by interconnecting wires; encased coils are not connected, but the fabric encasement helps preserve the mattress shape.

Here are five types of mattress coils:

  • Bonnell coils are the oldest and most common. First adapted from buggy seat springs of the 19th century, they are still prevalent in less expensive mattresses. Bonnell coils are hourglass-shaped, and the ends of the wire are knotted or wrapped around the top and bottom circular portion of the coil and self-tied.
  • Marshall coils are each wrapped in a fabric encasement and usually are tempered. In the case of Beautyrest, high carbon magnesium is added, while the steel itself remains untempered. Some manufacturers pre-compress these coils, which makes the mattress firmer and allows for motion separation between the sides of the bed.
    Bonell springs
  • Encased Coils or encased springs, are a component part of a mattress in which each coil is separately wrapped in a textile material. Encased coils may also be generically referred to as Marshall coils or wrapped coils.
  • Offset coils are designed to hinge, thus conforming to body shape. They are very sturdy, stable innersprings that provide great support.
  • Continuous coils Or Mira-coils, work by a hinging effect, similar to that of offset coils. In a basic sense a continuous coil is simply that, one continuous coil in an up and down fashion forming one row (usually from head to toe) of what appear to be individual coils. The advantages of how firm a support the continuous coil provides it is somewhat tempered with the "noise" associated from a typical Mira-coil unit. The largest company using a Mira-coil design, is Serta Mattress Company, though their coil units are supplied by Leggett & Platt.

Bonell springs are hour-glass shaped, which means their resistance increases with load. They are therefore best suited for firm mattresses. [my emphasis]

Pocket springs provide support along the entire length of the body. This design works to maintain natural spinal alignment throughout the night.

Re: Different kinds of springs and other info
Reply #30 Feb 1, 2010 12:39 AM
Location: L.A. area
Joined: Jan 18, 2008
Points: 1161
Leo3 wrote:
 This you might find interesting  http://www.epinions.com/content_2589958276
it is posted by a mattress developer in 2002 (still relevant)  that gives some insight to coils and which ones help/hurt a back, and why you back needs some cushion to fill up the small of your back to prevent lower back pain.  Be sure to look at the links page on consumersearch.com.


Thanks for that link. I bookmarked it and will get around to reading it sooner or later.
Re: Different kinds of springs and other info
Reply #31 Feb 1, 2010 12:44 AM
Location: L.A. area
Joined: Jan 18, 2008
Points: 1161
Leo3 wrote:
http://www.beddingcomponents.com/innersprings.asp

This is from Leggett and Platt website.  Now can someone tell me which mattresses use what components?  On the right hand column you can download the .pdf on bonnell and Marshall coil.  I am STILL trying to find out what my Spring Air from 15 years ago has.  I think Bonnell obviously, but those are the firmest from what I understand.  I am not even sure if the bed manufacturers still are using these.  Who knows?

Leo that site used to be very informative but now it's about only their latest technologies and no, there's no way of knowing who is using what...
what a weird business the mattress co's are running! They go to the trouble of making what looks like a very informative site but it has almost no useful information!
Yes, Bonnell is still very much used, and my Englander is supposed to have Bonnell. I say "supposed to have" because I have never seen any printed info on what is inside my Englander. And I was told different things by different salesmen. But my best guess is they are Bonnell 12.5 gauge springs.
Re: Different kinds of springs and other info
Reply #32 Feb 1, 2010 12:52 AM
Location: L.A. area
Joined: Jan 18, 2008
Points: 1161
Leo3 wrote:
http://www.beddingcomponents.com/innersprings.asp

 I am STILL trying to find out what my Spring Air from 15 years ago has.  I think Bonnell obviously, but those are the firmest from what I understand.  I am not even sure if the bed manufacturers still are using these.  Who knows?

I recall about 9 years ago when we bought our Sealys (BIG mistake!) that one store was trying to sell me a Spring Air that had "zoned" springs, I believe. Softer at the shoulder, firmer at the hips, something like that. I could be wrong, maybe it was the foam, but I'm pretty sure they showed me the springs.

That mattress my friend had that I liked so much was a Spring Air from 15 years ago. It's called a Majestic. But he had no info on the springs, only what was on the label. I guess the most important thing was on the label, though. It said, "Endorsed by orthopedic surgeons" ...

Hell, it was probably a very middle of the road bed back then but now it is probably better than anything you can buy without spending $3000+ !
Re: Different kinds of springs and other info
Reply #33 Feb 1, 2010 4:14 PM
Joined: May 30, 2009
Points: 9
If I remember correctly, 15 years ago Spring Air usually used a bonnell coil on their promotional coils. On the top of their line they used a368 offset 12 3/4 ga & then went to a 532 offset unknotted coil
Re: Different kinds of springs and other info
Reply #34 Feb 1, 2010 4:17 PM
Location: Yosemite area
Joined: Sep 10, 2008
Points: 249
Good thread, Jim;
From what I've gleaned, the main manufacturer of coils in america is L and P, and Sealy makes their own.  There are some independent spring makers but they typically only make the Bonnell units(ask Bill sometime...he gets specialty bonnnells).  There can be quality difference other than the type and gauge, depending on the processing of the wire...is it heat processed or electro processed?  That rearranges the molecules inside, can make the steel more brittle. 
Bill says that if a coil in a Bonnell  goes awry, it can be fixed.  Not so with continuous coils...the whole thing needs to be scrapped.  I think that was his objection to offsets as well, but I have to wonder just how often that happens.  But it must from time to time.
Wickipedia is a compilation of information gleaned from the internet, so it is just more sites rolled into one, not necessarily full truth.
Kait
This message was modified Feb 1, 2010 by Kait
Re: Different kinds of springs and other info
Reply #35 Feb 1, 2010 4:44 PM
Joined: May 3, 2008
Points: 827
jimsocal wrote:

But for the companies, what about next year? Aren't they worried about losing customers or losing good employees, or ...?
Next year doesn't matter. It's all about making profit NOW. All that matters is the Almighty Dollar.

Huh?
I feel like I woke up to a bad dream.
What happened to this country?
What happened to companies caring about their employees? What happened to companies trying to make the greatest highest quality product they could? What happened to caring about the future of the business, the future of the employees, the future of the planet... our future?

Forgive me. I'll get off my soap box now.

I agree.  I was still trying to read about Spring Air history to see where they went wrong.  You can't find much except twice now it has done chapter 7 and/or 11, and at "Furniture Today" website I found an article on how not to close a plant, regarding how Spring Air put a letter on the door and the employees came into work to find no job, no health care, and no Cobra options.  Nice huh?  A CEO and VP (I think) sued for severance pay (this was the first bankruptcy) and won.  A former employee (recently) is suing Spring Air because you are suppose to give 60 days notice for plant closure.  Hope they get some justice.  I feel really bad for employees nowadays, we get a really bad deal.  This in turn gives consumers less choice and probably higher prices, no competition the companies don't have to have good prices anymore.

Maybe this will make smaller mattress companies succeed, if they make a good product.  Not many people will choose these S manufacturers that keep filing chapter 7/11 and selling to another company and then another......

Off soap box now.
Re: Different kinds of springs and other info
Reply #36 Feb 1, 2010 5:03 PM
Joined: May 3, 2008
Points: 827
mattmanu wrote:
If I remember correctly, 15 years ago Spring Air usually used a bonnell coil on their promotional coils. On the top of their line they used a368 offset 12 3/4 ga & then went to a 532 offset unknotted coil

That went right over my head.  I wish I knew what a 532 offset unknotted coil was, LOL, or a 368 offset.  What are promotional coils?  I understand bonnell coils LOL.
Re: Different kinds of springs and other info
Reply #37 Feb 1, 2010 5:16 PM
Joined: May 3, 2008
Points: 827
jimsocal wrote:
I recall about 9 years ago when we bought our Sealys (BIG mistake!) that one store was trying to sell me a Spring Air that had "zoned" springs, I believe. Softer at the shoulder, firmer at the hips, something like that. I could be wrong, maybe it was the foam, but I'm pretty sure they showed me the springs.

That mattress my friend had that I liked so much was a Spring Air from 15 years ago. It's called a Majestic. But he had no info on the springs, only what was on the label. I guess the most important thing was on the label, though. It said, "Endorsed by orthopedic surgeons" ...

Hell, it was probably a very middle of the road bed back then but now it is probably better than anything you can buy without spending $3000+ !

Spring Air's website does show the "zoned" springs like you saw 9 years ago then.  That is what they are selling now.  That is not what I have from 15 years ago.  Another gimmick that probably doesn't work!

My Spring Air from 15 years ago was called four seasons I thought, but that is what they named everything.  You also know names mean nothing, you can't compare my Spring Air to your friends, because we bought them at different stores and they change the names to protect the guilty, LOL!  See if his has silk fabric on one side, and wool on the other, mine does.  That is my advice to anyone who has an old filippable mattress, KEEP IT.
Re: Different kinds of springs and other info
Reply #38 Feb 1, 2010 5:57 PM
Joined: Dec 17, 2009
Points: 850
Leo3 wrote:
Thanks for the info.  I thought you were too young to know, guess I was wrong.  But Spring Air was popular in the US here.  I thought they didn't start changing hands until 5 years ago.  They were changing hands before that???

I knew Simmons had the wrapped kind, at least when I went looking you can feel the difference on those mattresses.  I never thought those wuld hold up in the long run.  Do they?  Doesn't matter now though Simmons is gone, but maybe someone will revive them.

There are a lot of rumours about what will happen with Serta and Simmons these days.  I don't think they are going to vanish just yet.  With regards to their pocket coils, they actually used to hold up exceptionally well.  If a pocket coil is well made it is in theory maybe even more durable than other spring systems because there are no lacing wires to destroy, and the lacing wires are always the weak point with any normal spring system.  But again, in this day and age this is totally irrelevant because the foam will break down long before this becomes an issue. 

And yeah, I am probably a little too young to know, its a good thing I have family thats been in the industry for a long enough time to know these things and pass it on to me.  I also have some limited first hand experience, we had a really old Simmons in our guest room that was probably 20 years old and felt pretty good, this was some time ago so I would say the mattress would have been built in the early 80's, so even though there was poly foam in it, it was a minimal amount. I have also cut open a lot of older mattresses taken from customers homes before they head off to be recycled. Lots of old Sealy's and Simmon's, most of the coils looked to be in very good shape. 
Re: Different kinds of springs and other info
Reply #39 Feb 1, 2010 6:19 PM
Joined: Dec 17, 2009
Points: 850
Leo3 wrote:
Spring Air's website does show the "zoned" springs like you saw 9 years ago then.  That is what they are selling now.  That is not what I have from 15 years ago.  Another gimmick that probably doesn't work!

My Spring Air from 15 years ago was called four seasons I thought, but that is what they named everything.  You also know names mean nothing, you can't compare my Spring Air to your friends, because we bought them at different stores and they change the names to protect the guilty, LOL!  See if his has silk fabric on one side, and wool on the other, mine does.  That is my advice to anyone who has an old filippable mattress, KEEP IT.

Yeah zoned springs IMO are a huge gimmick.  I will tell you what lead me to believe so.  My research on the worlds most expensive hand made mattresses made me realize that absolutely NONE of them zone their inner springs.  They might reinforce the edges, but they will never mess with actual sleeping surface.  My knowledge of suspension technology from being a hobbyist weekend auto-crosser gave me some rudimentary experience and understanding of how progressive springs work.  At the heart of it, all inner springs used in mattresses are progressive coils, meaning the diameter of the working wire is not the same through out the height of the coil itself.  A non zoned coil in one way shape or form ALREADY self adjusts the tension to match the weight of the sleeper in that particular area of the spring system.  If you bias the support in the middle of the spring system by either using a thicker steel or moving the coils closer together you are massively overcompensating, and it really just prevents the coils from doing the job they are designed to do. 

There is also the issue about the height of people being different, as well as the shape of a man vs a woman of the same height and weight.  The only way you can really bias support without compromising the ability of the bed to conform to the shape of someones body is to use different types of lateral support built into the base or the mattress ie; a slat system with adjustable tension in the mattress or the base.  It is however very rare to see this, because its expensive to do, and it somewhat complicates the process for some people who don't want to fuss around with these sorts of things.