Spring coils for innerspring assemblies and methods of manufacture

U.S. Patent 8,979,079

Issued March 17, 2015

Abstract

A progressive spring coil comprises a first spring portion comprising a top end and a bottom end and having a first spring rate, wherein the first spring rate is substantially linear or substantially nonlinear; a second spring portion comprising a top end and a bottom end and having a second spring rate, wherein the second spring rate is substantially linear or substantially nonlinear; and a third spring portion disposed between the first spring portion and the second spring portion, wherein the third spring portion has a third spring rate, wherein the third spring rate is substantially linear or substantially nonlinear.