| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method and apparatus for quickly and reliably measuring the preferred angular orientation of a golf club shaft. <P>SOLUTION: A preferred orientation, or planar oscillation plane of the shaft 110 of a golf club is determined by measuring the oscillation of the shaft 110 when an impulse is applied. Preferably, the out-of-plane oscillation is measured at a large number of angular positions to the shaft 110 axis, and the principal planar oscillation plane is identified by a pair of opposed angular positions in which the out-of-plane oscillation is smallest. The location of the preferred orientation may be marked on the shaft 110, and is used for manufacturing the golf club having the planar oscillation plane in a predetermined orientation. The straightness of the shaft 110 can also be determined by deriving its spring constant from its oscillation frequency, and then, measuring the restoring force when the shaft is deflected by the same nominal amount at different angular positions. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
