Patent ID: 8096925

Claim:
A method of making a treadmill belt comprising: applying at least one layer of a first unfoamed thermoplastic composition on and integral with a substantially non-extendable fabric base layer; foaming the first unfoamed thermoplastic composition to define a first foamed cushion layer, wherein the first unfoamed thermoplastic composition is a polyvinyl chloride composition that includes 100 parts polyvinyl chloride and 1 part to 5 parts of a foaming agent per 100 parts polyvinyl chloride, wherein the first foamed cushion layer has a Shore A hardness of about 20 to about 80, and wherein the first foamed cushion layer is from 0.05 inches to 0.35 inches thick; applying an outer wear layer on and integral with the foamed cushion layer to define the treadmill belt with first foamed cushion layer, wherein the outer wear layer is comprised of natural rubber or a synthetic rubber; and securing a bottom surface layer to the underside of the fabric base layer, wherein the bottom surface layer is comprised of a thermoplastic material selected from the group consisting of polyvinyl chloride and polyurethane; wherein said treadmill belt consists solely of (a) the substantially non-extendable fabric base layer, (b) the a first foamed cushion layer, (c) the outer wear layer, and (d) the bottom surface layer.