Upholstery coil springs are an important part of most modern upholstery. The consumer usually never sees the construction features of an upholstered piece, but they are important. The overall quality of the materials and construction techniques used dictate the comfort level of an upholstered piece and its ability to satisfy the consumer over the long term. A basic upholstered piece is composed of a frame, springs, foam, cushioning, padding, and textiles.
Coil springs are individual coils, open at both ends. They may be knotted at one end. When attached to webbing and twine-tied at the top, they form the 'springy' platform on which the loose cushion rests.
History
In 1763 R. Tredwell was issued the first patent for the coil spring, British patent No. 792. The main advantage of coil springs was that they did not have to be spread apart and be lubricated periodically to keep them from squeaking, as leaf springs did.
With the industrial revolution came the steel coil spring. It was first patented in America for use in a chair seat in 1857.
Heinrich Westphal was credited with inventing the innerspring mattress in 1871. Heinrich lived in Germany and never profited from his invention dying in poverty.