A golf club shaft connection assembly comprising first and second shaft sections, male and female adaptors, a hollow retainer, a spring, and a plurality of balls is disclosed herein. The male and female adaptors are each attached to the first and second shaft sections, respectively, preferably with a permanent adhesive. The male adaptor comprises a protrusion that fits within a keyed interior of the female adaptor, and moving the hollow retainer towards the male adaptor reversibly fixes the two adaptors together, while moving the hollow retainer towards the female adaptor allows the male adaptor to be removed from the female adaptor.

An iron-type golf club having selectively machined portions and attributes.

An iron-type golf club having selectively machined portions and attributes.

A golf club 2 includes a head 4, a shaft 6, and a grip 8. A club inertia moment about a swing axis is defined as Isw. A club inertia moment about a grip end is defined as Ige. Ige is 2920 (kg.Math.cm.sup.2) or greater and less than 2970 (kg.Math.cm.sup.2). Isw/Ige is equal to or less than 2.48. A club weight is defined as Wc (kg), an axial direction distance from the grip end to a center of gravity of the club is defined as Lc (cm), and a club inertia moment about the center of gravity of the club is defined as Ic (kg.Math.cm.sup.2). Isw is calculated by Equation (1) below. Ige is calculated by Equation (2) below.
Isw=Wc×(Lc+60).sup.2+Ic  (1)
Ige=Wc×(Lc).sup.2+Ic  (2)

A golf club 2 includes a head 4, a shaft 6, and a grip 8. A club inertia moment about a swing axis is defined as Isw. A club inertia moment about a grip end is defined as Ige. Ige is 2920 (kg.Math.cm.sup.2) or greater and less than 2970 (kg.Math.cm.sup.2). Isw/Ige is equal to or less than 2.48. A club weight is defined as Wc (kg), an axial direction distance from the grip end to a center of gravity of the club is defined as Lc (cm), and a club inertia moment about the center of gravity of the club is defined as Ic (kg.Math.cm.sup.2). Isw is calculated by Equation (1) below. Ige is calculated by Equation (2) below.
Isw=Wc×(Lc+60).sup.2+Ic  (1)
Ige=Wc×(Lc).sup.2+Ic  (2)

The invention relates to golf clubs, more particularly to mechanisms for fastening accessories to clubs. The invention provides a golf club configured to house an electronic device such as an RFID tag within a recess within the grip, thereby protecting the device from the stress, shock, and exposure that arises when a golf club is used.

The invention relates to golf clubs, more particularly to mechanisms for fastening accessories to clubs. The invention provides a golf club configured to house an electronic device such as an RFID tag within a recess within the grip, thereby protecting the device from the stress, shock, and exposure that arises when a golf club is used.

Provided is a weight pattern determination apparatus for determining, in a golf club having a head capable of mounting one or more weights in a plurality of mounting patterns, the mounting pattern suited to a golfer. The apparatus has an impact point specification unit and a pattern determination unit. The impact point specification unit specifies an impact point distribution of the golfer. The pattern determination unit determines a recommended pattern which is the mounting pattern that approximates a sweet area of the golf club to the impact point distribution. According to the first aspect of the present invention, the impact point distribution of the golfer is specified, and a mounting pattern is determined based on this impact point distribution.

The present invention provides a game racquet including an integrated circuit capable of supporting a low-voltage energy current. An embodiment of the invention provides a game racquet including one or more enhancements attached or integrated on the racquet frame. These enhancements may include but are not limited to: one or more LEDs, a sound amplification device, and an electromagnetic vibration emitter. In a further embodiment, the game racquet responds electronically to ball impact on at least one of the strings, and subsequently performs and action or actions including but not limited to making a sound or sounds, triggering lights, triggering LEDs, triggering another type of automation on the racquet such as a vibration emitter within the handle. The game racquet frame comprising at least one string channel in the frame head, bridge, or other area, which houses an actuator responds mechanically to a string movement triggering electronic connection.

The present invention comprises a golf club head comprising a body having a crown, a sole, a front wall and a hosel, wherein the body defines a hollow interior. The golf club head further comprises a center of gravity adjustment assembly wherein the center of gravity adjustment assembly is positioned within the hollow interior of the body, and allows the center of gravity of the golf club head to be adjusted by at least 0.050 inch, preferably along a vertical axis.