1. Field of the Invention
This invention relates to baseballs and softballs and more particularly to rubber and vinyl coated baseballs and softballs.
2. Description of the Prior Art
Baseballs, as are used in the United States, have been predominantly constructed of a cork or a rubber core wound with wool yarn and cotton thread, and covered with a two piece leather cover. Where the balls are used for practice, the cover is constructed of a thermosetting rubber to impart durability to the practice baseball.
In another aspect, baseball cores have been constructed of thermoplastic resins having foam decreasing in cell size radially outwardly to a skin. These cores and the method of making them are more fully disclosed in U.S. Pat. No. 4,144,297 entitled "Method of Injection Molding a Foamed Thermoplastic Resin Ball Core Having an Integral Skin" of Julius Tomar issued Mar. 13, 1979 and incorporated herein by reference.
Analogously, softballs have been made from predominantly a cork or kapok core wound with a synthetic yarn or thread, with a cover formed upon the surface of the softball much the same as the baseball. The aforementioned patent teaches a method of forming thermoplastic softball cores in the same manner as the baseball cores.
In the prior art method of rubber coating baseballs and softballs, the ball core is dipped in a thermosetting latex to partially impregnate the baseball or softball core and the latex is dried and cured in a mold to form the rubber coated baseball or softball. This method is time consuming and requires a drying and curing step.
In accordance with the present invention, a method of forming a rubber coated baseball or softball is provided which is efficient and provides a baseball or softball which has the requisite durability for repeated playing in a practice atmosphere. Further, a process of forming a vinyl coated baseball or softball is provided.
USPTO Backgrounds
USPTO Backgrounds