Motion Analysis Corporation

Stanley C Plagenhoef

Elastomeric shoesole

A set of golf clubs, including both woods an irons, is disclosed in which the various clubs are constructed in their various parameters to aid the user to insure that each and every swing of the club follows the correct path and also to resist rotation of the club head and shaft during impact with the ball about a variety of pivot points on the shaft to assure that the ball will travel in a true flight pattern. The club head is weighted to locate its center of percussion near the toe of the head to reduce rotation of the head at impact about the shaft axis and the handle of the club is weighted to locate the center of percussion of the club below the club head to reduce rotation of the club about the pivot point defined by the base of the index finger of the lower hand in the grip. In addition the shafts of the clubs are stiffened above the club head so that the zone of maximum flexibility of the shaft is about 40 cm above the hosel of the club head whereby the head will be moved forwardly relative to the rest of the club at impact to impart greater force to the ball and distance to the hit. And, the club grip is enlarged to enable the player to apply a greater force to the club resisting rotation of the club shaft in the player's grip.

Golf club and golf club set

An elastomeric shoesole designed specifically for athletic activities wherein the sole contains at the outer side of the heel and/or the inner side of the ball transversely-extending, longitudinally-spaced openings which extend to approximately the longitudinal center line and wherein the respective opposite sides are substantially solid, thereby allowing the sole to yield at the outer side of the heel end to a greater extent than at the inner side and at the inner side of the ball to a greater extent than at the outer side.

A standard size tennis racket has a flex of substantially 1.2 centimeters at the throat, 2.4 centimeters at the head center and 5.8 centimeters at the tip when a force of substantially thirty pounds is applied to the racket tip with the racket cantilevered from the handle end. A weight between 15 and 25 grams is located on one side on the frame at the midpoint of the strings, and a weight of between 15 and 25 grams is placed at the end of the handle, the weights being concentrated in as small an area as possible, the total weight of the racket counting the side weight only being substantially the same as a conventional unweighted racket. For a 27 inch racket, the weights are selected to establish a center of gravity between 123/4 inches and 13 inches from the end of the handle and the center of percussion between 22 and 221/2 inches from the end of the handle determined by using a pivot point 43/4 inches from the end of the handle. The side weight is preferably as close to the heavy end of the range as possible without having the center of gravity move above 13 inches, and the end weight is selected not only to keep the center of gravity below 13 inches, but to maintain the center of percussion within the stated range. Preferably, the grip on the handle allows the player to hold the racket in the correct portion with the side weight up without looking at the racket, being flat on the thumb side with a bulge to fill the palm 21/4 inches up from the end and a rounded area 41/4 inches up on the palm side.

Growing community of inventors

Amherst, MA, United States of America

Stanley C Plagenhoef