| 摘要 |
A football-shaped game ball is formed of a resilient foam material and defines an oblate spheroidal outer surface having generally pointed ends. A plurality of rib portions extend outwardly from the outer surface and define nonsymmetrical cross-sections. In the preferred embodiment shown, the rib portions define generally saw-tooth shaped cross-sections which may be gripped in either of two gripping manners and which provide differing alternative aerodynamic characteristics depending upon the direction of spin imposed upon the football.
|
