I remember when as a child I played with other children on a tilting board, variously called a "see-saw" or "teeter-totter." Pushing with our feet, we would alternately go up and down. Easy enough to do when we were both close to the same weight.
This was where we learned the principle of the balance scale. When one end goes down, the other goes up. and it's the heavier end that goes down. That's the way it was on the see-saw. With an average first grader and a fifth...
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...
[caption id="attachment_807" align="aligncenter" width="950"] Stearns & Foster's Intellicoil[/caption]
[caption id="attachment_806" align="aligncenter" width="123"] Serta's Duet Coil[/caption]
Pocket coils were invented at the end of the 19th Century (1800's) by James Marshall, who began manufacturing them about 1900. Since then, individually wrapped pocket coils have been adopted by most of the major manufacturers of innerspring...
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...
What kinds of springs are in your mattress?
The best selling mattresses over time have been innerspring mattresses. The first mattress springs were adapted from buggy seat springs. These springs are called Bonnell coils. For a long time, they were the only kind of springs used in mattresses. Now there are several types of innerspring coils. The major kinds are Bonnell, Offset, Continuous and Pocket. Within each of these kinds are variations. Each type of...