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.

A golf club head having elevated internal weighting that improves ball speed, reduces backspin, and increases launch angle is disclosed herein. In particular, the golf club head comprises a hollow body with a face, sole, and elevated weight bar, which is disposed inside the body and is fixed to heel and toe sides of the body, preferably with mechanical fasteners such as screws or bolts. The weight bar bridges a central portion of the sole, and a central section of the weight bar, which preferably comprises at least 50% of the overall mass of the weight bar, extends towards the face without actually making contact with the face. The sole also includes at least one slot extending perpendicular to the face and underneath the central section of the weight bar, the slot having a front-to-back length that is greater than a maximum front-to-back length of the weight bar.

Present invention discloses a golf swing practicing apparatus for practicing golf swing in a confined environment with a short-shaft golf club, practicing methods for setting up the short-shaft golf club at a proper incline angle in mid air at address position, and a mechanic model for determining the required club head weight that enables golfer to feel the same Swing Weight as he swings the short-shaft golf club or the conventional golf club.

A golf club fitting apparatus and a method for fitting using the apparatus are provided. The golf club fitting apparatus may be attached to a golf club and provide fitting information including effective lie angle, effective loft angle, stroke plane, and aiming verification information. That golf club fitting apparatus includes a first opening for receiving a shaft, second openings for receiving a collimated light source, third openings for receiving angle indicators, and a recess for securing the collimated light source in an alternate configuration.

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 2870 (kg.Math.cm.sup.2) or greater and less than 2920 (kg.Math.cm.sup.2). Isw/Ige is equal to or less than 2.46. 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 2870 (kg.Math.cm.sup.2) or greater and less than 2920 (kg.Math.cm.sup.2). Isw/Ige is equal to or less than 2.46. 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 current invention aims at improving the playability, durability, and spin generation of different playing rackets, as tennis, squash, and badminton rackets. The method to do so is by applying mechanical forces which generate relative motion of the latitudinal strings over the longitudinal strings. This is done in order to create friction that generate depressions in the contact points of the latitudinal strings with the longitudinal strings. These depressions, made by the described method and machine, induce more friction, and generate spin, while increasing the playability and durability during the play.

The current invention aims at improving the playability, durability, and spin generation of different playing rackets, as tennis, squash, and badminton rackets. The method to do so is by applying mechanical forces which generate relative motion of the latitudinal strings over the longitudinal strings. This is done in order to create friction that generate depressions in the contact points of the latitudinal strings with the longitudinal strings. These depressions, made by the described method and machine, induce more friction, and generate spin, while increasing the playability and durability during the play.

A a method of making set of a plurality of at least a combination of three golf clubs of progressive lofts that are matched to provide identical swing characteristics; each of the golf clubs including a club head, a shaft and a grip at the upper end of said shaft; each club of the combination characterized by having an essentially identically located, computer designed center of gravity; each club being further defined by the shaft having an equal length, having an identical swing weight, identical grip weight and an identical club head weight.

A motion sensor package with an elastomer layer that encases the sensor electronics, including the sensors, a processor, an antenna, and a battery. The elastomer layer may provide shock isolation and water resistance to protect the enclosed electronics. Embodiments may also include an outer housing into which the elastomer encased package is installed. The outer housing may for example comprise two cylindrical sections that screw together to close the outer housing. In one or more embodiments part of the outer housing may be integrated into an item of sports equipment. Embodiments for golf may also include a golf club grip adapter that is inserted into the top of a grip, and which attaches to the outer housing containing the elastomer enclosed sensor package.