Ball
AssigneeOyo Rubber Chemical Industry Co., Ltd.
InventorsSadao Kumasaka, Satomi Tada
Life of this patent
Estimating the term…
Abstract
The invention provides a ball for a game having a spherical soft polyurethane foam and a surface layer of foamed polyvinyl chloride formed on the surface of the spherical body. The ball is produced by first casting the surface layer in a mold to form a hollow foamed PVC body having closed cells, and then charging a foamed polyurethane composition into the hollow thus formed, to produce a sphere of polyurethane having open cells within the surface layer. Also provided is a ball for games having a spherical body of foamed polyvinyl chloride and having a spherical cavity at the center. The ball is safe, has proper flexibility, and is not subject to punctures.
Claims5
A ball comprising:
- a spherical body of polyurethane foam having open cells, and
- a surface layer of foamed polyvinyl chloride having closed cells integrally formed on the surface of said spherical body of polyurethane foam;
- said ball having been produced by forming said surface layer by rotational casting in a mold to form a hollow foamed polyvinyl chloride body having closed cells and a central cavity therein and charging a foamable polyurethane composition into said cavity and foaming said composition to integrally form a spherical body of polyurethane foam having open cells integral with said surface layer of foamed polyvinyl chloride having closed cells.
The process of forming a ball comprising rotationally casting foamable polyvinyl chloride to form a hollow spherical polyvinyl chloride layer having closed cells and a thickness of from 2 to 10 mm;
- and charging a foamable polyurethane composition into the cavity formed in the interior of said hollow polyvinyl chloride spherical body and foaming said polyurethane composition to form a spherical body of polyurethane foam having open cells integral with and internal of said spherical body of foamed polyvinyl chloride thereby forming a ball having a surface layer of said foamed polyvinyl chloride having closed cells integral with said spherical body of polyurethane foam having open cells.
Dependencies are inferred from the claim text.