Progressive Rate Springs:
What Are They Doing in My Bed?
If anyone of us knows what progressive rate springs (PRS) are, the first place we expect them is in wheeled vehicles. In fact, that is the intended application of progressive rate coiled springs, and that is what comes up first in an online search. So it surprising to find "progressive rate springs" in the description of a mattress. And a waterbed mattress, no less!
Before we go on, let's see what a progressive rate spring is. Some...
The smallest mattress coils so far
It used to be that the shortest mattress coils were the 4" Bonnell coils in a sofabed mattress. The reason they were so short, when most coils were 7 or 8 inches high, was so the mattress could be folded to fit inside the sofa under the seat cushions.
With the introduction of pocket coils, the trend was for innerspring coils, at least the wrapped coils, to become taller, up to 9 or 10 inches. This allowed greater conformabiity and more...
Minicoils or Microcoils?
A previous blog article, Microcoils, covered the use of coils in mattresses that are significantly smaller than innerspring coils. In this article, I noted that some of these smaller coils are much smaller than others, and that there has not been a concensus on terminology.
Until now, the whole category of small springs has been classified as microcoils. But now several manufacturers are placing two layers of these coils above the support core of a mattress....
In February 2014, I posted an article about wood coils, a new kind of mattress innerspring invented and developed by a Hungarian company. Not long before the launch of wooden coils in the bedding market, another new kind of mattress spring was invented and introduced into the market by Willy Poppe, a Belgian. Poppe is CEO of a family-owned bedding manufacturer, Diamond Spring Company, in Sint-Niklaas, East Flanders, Belgium.
Pocket (Marshall) Coils
[caption id="attachment_731" align="aligncenter" width="300"] Pocket coils Image from Simmons Beautyrest[/caption]
Pocket coils, also known as pocketed coils, encased coils, wrapped coils or Marshall coils, are light gauge open-end coils in fabric pockets. They were invented in 1900 by James Marshall, an Englishman who migrated to Canada. In Toronto, Ontario, Canada he founded the Marshall Mattress Company to make mattresses using his technology. The company is...
[caption id="attachment_719" align="aligncenter" width="347"] Looking down rows of continuous coils Image from Bedrooms & More, Seattle, Washington[/caption]
Continuous coils are the least expensive type of coils used in innerspring mattresses. According to Seattle Mattress Company, this coil type was invented by Serta. Currently, Serta is the largest user of continuous coils. Serta's continuous coils are manufactured by Leggett & Platt under the trade name...
Offset (Karr) Coils
[caption id="attachment_705" align="aligncenter" width="642"] Offset Coil System Image from Bedrooms & More, Seattle, Washington[/caption]
Offset coils, also called Karr coils, were invented in the early 1900s by Frank Karr, who also started the Spring Air mattress company. They were developed from Bonnell coils, the original support for innerspring mattresses. Since the inception of offset coils, they have been used by many other mattress companies.
Bonnell Coil System,
Image from Bedrooms & More, Seattle, Washington
The oldest type of coil used in mattresses is the Bonnell coil. Bonnell coil mattresses are often called "traditional mattresses" or "traditional innerspring mattresses." Other types of coils have been developed since, but they all originate in the Bonnell coil.
Bonnell coils themselves were developed from buggy seat springs. They are hourglass shaped. The ends are knotted, the end of the wire...
Just as a foundation supports a building, so a foundation supports a mattress. When mattresses were first made, they sat directly on the ground or the floor. Sometimes the mattress was set on a raised area, a platform or ledge, which then became the foundation. This helped keep the bed dry and warm. At some point in time, those who could afford it had beds with legs built to hold the bed off the floor with free space underneath.
Raised beds are not new. The Old Testament book...
by Wesley Vaughn
[caption id="attachment_342" align="aligncenter" width="397"] Sealy Mattress and Box Spring[/caption]
It is common knowledge that we need sleep, and that—for the most part—several factors determine whether and how we sleep. Among these factors are time of day, how tired we are, physical condition, medication, diet, amount of light, noise, vibration and motion, warmth and cold, pain and comfort.
Even knowing this much, it is easy for many people to...