This invention relates to a sport device of the type used in striking a sport object and propelling it at a distance from the user and in particularly, an improved golf club wherein player control is enhanced.
A number of sporting activities require the participant to grasp and move a sport device, be it a golf club, croquet or polo mallet in a controlled manner to strike and propel an object typically, a ball, toward a defined goal. In case of the game of golf, the goal is very much reduced in size so that very precise strokes are needed to ultimately place the sport object in the hole.
The overall weight of the club determines whether or not the user has sufficient strength to handle the club. Adjustments to the overall weight are typically made by adding material at the handle and/or in the region where the clubhead or striking surface is joined to the end of the club shaft. In the case of golf clubs, this region proximate to the head is termed the hosel. While overall weight is significant for the user, performance is affected as well by the swing weight of the club.
In the athletic goods industry, swing weight of a club refers to the relationship of the clubhead weight to the overall weight of the club. The swing weight scale has sixty gradations each of which signifies a certain ratio of weights apart from the overall club weight. As the clubhead weight increases with an increasing swing weight, the shaft bends more during the swing and the club swings heavier and slower. The traditional method of altering swing weight in a golf club is to disassemble the club and add or subtract lead in the hosel region where the head meets the shaft. However, the swing weight can also be altered during manufacture by adding weight to the handle region if the clubhead can no longer tolerate the removal of additional material.
The combination of simultaneously changing clubhead and handle-region weights to accommodate a particular player's preference without altering the overall weight of the club has been suggested in the past. The adjustments needed to move several gradations on the swing weight scale are slight since one gradation is approximately equal to the weight of a dollar bill. An experienced golfer can typically sense a variation of three gradations in swing weight.
While swing weight is important for the feel and performance of clubs used to propel the ball large distances, the significance thereof decreases when the distances are shorter. Stability of the club when within the player's grasp is increasingly important as the accuracy demanded of the club increases, the most sensitive club being the putter with which the ball is taken to the hole. The need for enhanced stability has generated a family of golf clubs wherein weight distribution within the club head has been altered without changing overall club weight or the swing weight. Primarily this occurred through the concentration of the head weight in regions on either side of the striker by making the surface area smaller or reducing its thickness.
These steps to provide clubs with variable swing weights or altered clubheads have concentrated their efforts on maintain- ing the overall weight characteristics constant. These changes have relied upon the use of techniques acting within the length of the club and to this end have not directed their attention to providing stabilization by intentionally moving the center of gravity of the club closer to the hand-grip region of the club.
Accordingly, it is an object of the present invention to provide sport clubs with improved stability especially those clubs wherein the need for accuracy is paramount. This invention enables the user to alter the distance with which the center of gravity of the club is moved along the shaft without requiring assistance from the manufacturer or a technician. Furthermore, this invention can be installed on existing clubs and still permit modification of the effect by the user according to his perception of the stabilizing effect required for his game.