Method of evaluating the vibration characteristics of a sporting implement such as a golf club
First Claim
1. A method of evaluating the vibration characteristics of a sporting implement, wherein the sporting implement includes a shaft having a hitting member with the hitting member including a hitting face that is designed to impact with and propel an object, which comprises:
- (a) identifying a plurality of the natural frequencies of vibration of the sporting implement which frequencies produce node lines on the hitting member; and
(b) locating relative to the face of the hitting member the node lines present on the hitting member for the natural frequencies identified in step (a).
1 Assignment
0 Petitions
Accused Products
Abstract
A method of evaluating the vibration characteristics of a golf club comprises identifying the natural frequencies of vibration of the golf club through a pseudorandom vibrational excitation of the club. The club is then excited at least at some of the identified natural frequencies and the club head is observed under a strobe light to identify and locate on the face of the club head the node lines corresponding to the vibrational mode shape for these natural frequencies. The intersection pattern of the node lines as observed and mapped on the club face and the offset of this pattern from the presumed sweet spot provides important information as to the likely feel this particular golf club will have. In addition, a method of impacting a golf club at the sweet spot with a predetermined force is disclosed to simulate the impact of the club with a golf ball. The frequency response curve represented by the vibration levels as a function of frequency is a useful indicator of the gross or absolute levels of vibration of the club. Various golf clubs can be compared against one another by comparing the areas underneath the frequency response curves for the various clubs.
70 Citations
13 Claims
-
1. A method of evaluating the vibration characteristics of a sporting implement, wherein the sporting implement includes a shaft having a hitting member with the hitting member including a hitting face that is designed to impact with and propel an object, which comprises:
-
(a) identifying a plurality of the natural frequencies of vibration of the sporting implement which frequencies produce node lines on the hitting member; and (b) locating relative to the face of the hitting member the node lines present on the hitting member for the natural frequencies identified in step (a). - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of evaluating the vibration characteristics of a sporting implement, wherein the sporting implement includes a shaft having a hitting member with the hitting member including a hitting face that is designed to impact with and propel an object, which comprises:
-
(a) identifying the natural frequencies for various modes of vibration of the sporting implement including at least a first linear mode, a second linear mode, and a first angular mode; (b) identifying the presence and location of node lines for at least the second linear mode and the first angular mode of vibration on the hitting member; and (c) wherein step (b) is performed for a sufficient number of natural frequencies to allow a triangular area formed by the intersection of at least three node lines on the hitting member to be identified on the hitting face. - View Dependent Claims (9, 11)
-
-
10. A method of evaluating the vibration characteristics of a sporting implement, wherein the sporting implement includes a shaft having a hitting member with the hitting member including a hitting face that is designed to impact with and propel an object, which comprises:
-
(a) impacting a first sporting implement at the hitting face with a predetermined force in a manner that is representative of impact of the object with the sporting implement; and (b) measuring a parameter indicative of vibration levels occurring at the hitting face as a result of the predetermined force impact of step (a) with such parameter per unit of force being plotted along a vertical axis as a function of increasing frequency of vibration which is plotted along a horizontal axis, such plot defining a frequency response curve with the area between the curve and the horizontal axis being representative of the absolute amount of vibration occurring at the first sporting implement for the predetermined force impact. - View Dependent Claims (12, 13)
-
Specification