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:
Jul. 11, 2006
Filed:
Jun. 15, 2004
Applicants:
Hiroyuki Takeuchi, Hyogo, JP;
Kunio Niwa, Hyogo, JP;
Takeshi Ashino, Hyogo, JP;
Inventors:
Assignee:
SRI Sports Limited, Kobe, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
A63B 49/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
A tennis racket frame (), including a sleeve composed of a fiber reinforced resin, having a weight not less than 180 g nor more than 270 g, when strings are not mounted in a ball-hitting face thereof surrounded with a head part thereof. Supposing that the strings are not mounted in the ball-hitting face, a secondary natural frequency (F) of the racket frame in an in-plane direction thereof is set to not less than 200 Hz nor more than 320 Hz, a secondary natural frequency (F) thereof in an out-of-plane direction thereof is set to not less than 480 Hz nor more than 650 Hz, and F/Fis set to not less than 0.3 nor more than 0.6.