The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 27, 1990
Filed:
Mar. 04, 1988
Minoru Yoneyama, Niigata, JP;
Yonex Kabushiki Kaisha, , JP;
Abstract
In a tennis racket whose frame and handle shaft are integrally made of fiber reinforced plastics and the frame defines a strung surface, the frame is so designed that its first thickness 't' in a direction of the strung surface is substantially uniform around the circumference of the frame and its second thickness 'T' in a direction perpendicular to the strung surface is gradually varied. The second thickness is maximum at side sections of the frame interposing a sweet spot in the strung surface and is minimum at the top and bottom portions of the frame in such a manner that the maximum thickness is thicker in the range from 35% to 60% than the minimum thickness, which increases a weight per unit length of the frame toward the side sections.