| 摘要 |
484,433. Table-tennis balls. MABEE, D. C. April 14, 1937, No. 10654. Convention date, April 17, 1936. [Class 132 (ii)] A hollow table-tennis ball 1 of relatively thin flexible celluloid or similar cellulose ester or ether compounds comprises a plurality of sections joined by a circular reinforcing seam 2 of predetermined rigidity, each section being internally deformed to provide reinforcements on opposite sides of the seam to compensate for the increased rigidity at the seam so that the ball is of substantially uniform flexibility throughout its spherical surface. The reinforcements may consist of internal ribs 6, 9, formed in various patterns, or the wall itself may be gradually thickened on opposite sides of the seam. |
