Inflatable sports balls, such as soccer balls, volley balls, hand balls consist of an outer body in the form of a sphere and an inflatable bladder disposed therein. Sports balls of this type are often formed by joining discrete panels together, e.g. by stitching, along their respective adjacent edges. Shishido et al. U.S. Pat. No. 4,856,781 suggests use of a sewing or stitching machine to join the panels together.
To enhance durability, and to resist enlargement of the ball over time, e.g. due to action of the compressed air contained within the bladder, a sports ball may have a wound core, i.e., an inflatable bladder covered with windings of thread, e.g. nylon yarn.
USPTO Backgrounds
USPTO Backgrounds