Golf club shaft fitting method
First Claim
1. A fitting method, of a shaft of a golf club, for selecting a shaft having a torque matching a golfer based on a swing of the golfer, the method including the steps of:
- obtaining measurement values from a sensor attached to a grip of the golf club and capable of measuring angular velocities about three axes when a golf ball is hit by the golf club;
obtaining a predetermined index value for the angular velocities quantified from the measurement values; and
selecting a shaft matching the golfer from among multiple shafts whose torques have been measured in advance, based on a relationship established through test-hitting performed in advance between the index value and a torque of a shaft,wherein, when x-axis is oriented in a direction along toe-heel direction of a golf club head, when y-axis is oriented in a direction in which a ball is hit, and when z-axis is oriented to match an axial direction of a shaft, the fitting method further includes the steps of;
determining address, top, and impact of a swing from the measurement values;
calculating t_ω
y_max˜
imp, which is a time from when a grip angular velocity about the y-axis becomes maximum during a downswing to when the impact occurs;
calculating ω
x_ω
y_max˜
, which is an average value of a grip angular velocity about the x-axis from when the grip angular velocity about the y-axis becomes maximum to when the impact occurs;
calculating, as the index value, a magnitude of a change amount of the grip angular velocity about the x-axis per unit of time by dividing the calculated ω
x_ω
y_max˜
imp by t_ω
y_max˜
imp; and
calculating the torque of the shaft from the calculated magnitude of the change amount of the grip angular velocity about the x-axis per unit of time, using an approximate formula that is prepared in advance through test-hitting and that expresses a relationship between a torque of the shaft and the magnitude of the change amount of the grip angular velocity about the x-axis.
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Accused Products
Abstract
A fitting method, of a shaft of a golf club, for selecting a shaft having a torque matching a golfer based on a swing of the golfer. The method includes the steps of obtaining measurement values from a sensor attached to a grip of the golf club and capable of measuring angular velocities about three axes when a golf ball is hit by the golf club; obtaining a predetermined index value for the angular velocities quantified from the measurement values; and selecting a shaft matching the golfer from among multiple shafts whose torques have been measured in advance, based on a relationship established through test-hitting performed in advance between the index value and a torque of a shaft.
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Citations
7 Claims
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1. A fitting method, of a shaft of a golf club, for selecting a shaft having a torque matching a golfer based on a swing of the golfer, the method including the steps of:
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obtaining measurement values from a sensor attached to a grip of the golf club and capable of measuring angular velocities about three axes when a golf ball is hit by the golf club; obtaining a predetermined index value for the angular velocities quantified from the measurement values; and selecting a shaft matching the golfer from among multiple shafts whose torques have been measured in advance, based on a relationship established through test-hitting performed in advance between the index value and a torque of a shaft, wherein, when x-axis is oriented in a direction along toe-heel direction of a golf club head, when y-axis is oriented in a direction in which a ball is hit, and when z-axis is oriented to match an axial direction of a shaft, the fitting method further includes the steps of; determining address, top, and impact of a swing from the measurement values; calculating t_ ω _
ymax˜ , which is a time from when a grip angular velocity about the y-axis becomes maximum during a downswing to when the impact occurs;
impcalculating ω
x_ω _
ymax˜ , which is an average value of a grip angular velocity about the x-axis from when the grip angular velocity about the y-axis becomes maximum to when the impact occurs;calculating, as the index value, a magnitude of a change amount of the grip angular velocity about the x-axis per unit of time by dividing the calculated ω
x_ω _
ymax˜ by t_
impω _
ymax˜ ; and
impcalculating the torque of the shaft from the calculated magnitude of the change amount of the grip angular velocity about the x-axis per unit of time, using an approximate formula that is prepared in advance through test-hitting and that expresses a relationship between a torque of the shaft and the magnitude of the change amount of the grip angular velocity about the x-axis. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification