Invention Grant
- Patent Title: Racket frame
- Patent Title (中): 拍框架
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Application No.: US10866871Application Date: 2004-06-15
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Publication No.: US07074142B2Publication Date: 2006-07-11
- Inventor: Hiroyuki Takeuchi , Kunio Niwa , Takeshi Ashino
- Applicant: Hiroyuki Takeuchi , Kunio Niwa , Takeshi Ashino
- Applicant Address: JP Kobe
- Assignee: SRI Sports Limited
- Current Assignee: SRI Sports Limited
- Current Assignee Address: JP Kobe
- Agency: Birch, Stewart, Kolasch & Birch, LLP
- Priority: JP2003-297540 20030821
- Main IPC: A63B49/02
- IPC: A63B49/02

Abstract:
A tennis racket frame (10), 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 (F1) 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 (F2) thereof in an out-of-plane direction thereof is set to not less than 480 Hz nor more than 650 Hz, and F1/F2 is set to not less than 0.3 nor more than 0.6.
Public/Granted literature
- US20050043124A1 Racket frame Public/Granted day:2005-02-24
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