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:
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. |
Thanks for that link. I bookmarked it and will get around to reading it sooner or later. |
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. |
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+ ! |
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 |
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
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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. |
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. |
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. |
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. |
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. |