Soft game ball including moveable lubricated core

摘要

A game ball is comprised of an outer layer of foamed polyurethane plastic having a density of approximately 15 pounds per cubic foot, the layer having an external integral skin having a density of 20-30 pounds per cubic foot providing a protective cover and an integral inner skin having a density of 20-30 pounds per cubic foot providing a cavity in which a core ball of resilient material is contained. The core ball has a density of 70-76 pounds per cubic foot and a lesser degree of compressibility than the foamed layer of polyurethane plastic. The core ball is lubricated by carbon contained in the core ball when fabricated from natural rubber and by means of a lubricating film when fabricated from natural rubber and polybutadiene so that in either case the core ball is free to move or shift within the cavity when the baseball is impacted by a bat.