Patent Application
20060019765
The present invention relates to improvements in golf clubs, more specifically to an improved design for a club used to roll the golf ball on the putting green, otherwise known as a golf “putter”.
In the game of golf, there are two distinct and very different types of strokes used to advance the ball toward a desired target, the “hole”. The full swing is used with the majority of the clubs needed to play the game. The primary objective of the full swing is to generate both distance and accuracy. The full swing utilizes the majority of the muscles in the body to generate maximum distance, causing the ball to fly into the air for up to several hundred yards. The shoulders, arms, wrists, back, hips and legs are all very active in the full swing. The second, very different, type of stroke used in the game of golf is the putting stroke. The objective of the putting stroke is to roll the ball along the putting surface toward the “hole” and eventually into the hole. In the putting stroke, achieving maximum distance is of no concern since it is usually used within 90 feet of the hole. This distance can easily be achieved without the use of the larger muscle groups of the body. The golfer only wants to roll the ball into the hole. Should the ball fail to roll into the hole it is desired to stop as close to the hole as possible to improve the chances of holing the next putt. The most consistent putting strokes are best characterized as a pendulum motion. Only the shoulders and arms are used to swing the club unlike the full swing where the legs, wrists, hips and back are all very active. Therefore, the putter should be designed to allow the golfer to develop a smooth consistent stroke without the limitations imposed for the use of the other golf clubs.
In the putting stroke, feel is critically important. Feel allows a golfer to judge just how hard to strike the ball. The best putting strokes utilize a constant acceleration of the putter head to achieve the desired distance. Should the acceleration of the putter vary during the forward portion of the stroke, the putter head would twist off line causing errors in distance and accuracy. The absolute distance the ball rolls is a function of the degree of acceleration as well as the length of the stroke. Since the only part of a golfer's body that controls the putter are the hands, all the feedback regarding the acceleration of the putter is transmitted to the golfer through the hands and wrists. It is this pressure on the hands and wrists associated with the act of accelerating the club that is commonly referred to as “feel”. However, during the act of making a putting stroke, there are two components of acceleration that are sensed by the hands and wrists. The first component as stated above is the desired acceleration of the club, the second is the acceleration effect due to gravity. While the golfer is trying to achieve a very specific and constant amount of acceleration during the stroke, the gravity component associated with the club is producing a continuously varying amount of torque sensed by the hands and wrists. In order for the golfer to more easily achieve a consistent, accurate stroke the component of acceleration sensed by the wrists and hands associated with gravity must be greatly reduced or eliminated. Thereby, the golfer is only sensing the component of acceleration he is trying to create.
While there is a significant amount of prior art describing methods to add various amounts of weight at different locations on a golf club to improve playability, the previous patents have failed to understand and address a major issue associated with developing a good putting stroke and designing the weighting system around eliminating the gravity effect.
In prior art such as U.S. Pat. No. 1,210,182, Lynch describes fitting the butt end of the golf club with a cap of suitable quantity of lead to improve the balance. The lead is over wrapped with the leather that makes up the grip. Lynch only discloses a driver, not a putter.
In U.S. Pat. No. 1,658,447, Lantz describes another method for counter weighting a golf club with a similar objective as Lynch. Lantz describes using a “relatively short cylinder of some suitable metal conforming in diameter and taper to the diameter and taper of the shaft.” The shaft and counter weight are then over wrapped with a grip material. Lantz also states that the counter weight is constructed so as to not interfere with the player's natural grip. Lantz's approach attempts to improve full stroke by adding small amounts of weight to improve the balance of the club in the hands for clubs of the driving type, not putters.
In U.S. Pat. No. 4,690,407, Reisner describes a new technique for attaching small amounts of weight to the grip. Ideally the weight is integrally molded into a portion of the hand-grip. Reisner states the purpose of the counterweight is to move the folcrum point of the club toward the grip. This will “dramatically increase the distance and control the ball's flight” in an iron, not a putter. Reisner states that in his design the grip itself completely surrounds the weight and retains it securely on the shaft without adding any length to the shaft. Finally, Reisner states that the optimum amount of weight for counter-balancing a golf club is between 75 and 100 grams, with a total range between 50 and 150 grams.
In U.S. Pat. No. 4,461,479 Mitchell states that weight should be added to the grip end of the club in order to shift the balance point of the club such that it is near the midpoint of the golf club. The weight is to be inserted into the end of the shaft thus limiting the amount of weight that can be added. Additionally, Mitchell states the amount of weight needed for the desired effect for various clubs in a table. On average the desired amount of added weight is 4 ounces (113 grams).
Appledorn, in U.S. Pat. No. 5,364,102, adds about 8 ounces (227 grams) to the end of the putter type golf club inside the shaft. This is seen as an improved technique for manufacturing a weighted golf club. Appledorn states that he provides a swing balanced putter.
In U.S. Pat. No. 5,746,664 Reynolds describes a putter that can be modified to account for the speed of greens or a player's feel by adding or removing weights in various locations including the grip end of the shaft. In this invention, small plugs can be added or removed to slightly modify the balance of the putter.
In yet another method of adding weight to a golf club, Okoneski, U.S. Pat. No. 5,716,289, describes a different approach to adding 5 to 50 grams of weight to the grip end. It is once again being attached inside the shaft with the preferred amount of weight being 8 to 20 grams.
Kobayashi, in U.S. Pat. No. 5,269,518, develops several mathematical equations to help determine the desired ratio of head weight to grip weight. Based on many factors involving energy transfer, head velocity and moments of inertia to name a few, it is determined that the desired weight for the grip is between 100 and 260 grams. This is an addition of 40 to 200 grams since a standard grip is stated to weigh about 60 grams. Additionally, field tests showed that putters that had additional weights of 100 to 150 grams felt the best to most golfers. Putters that had an additional 200 grams of weight were too heavy.
In U.S. Pat. No. 3,679,207, Florian discloses a non standard putter for use with a croquet style putting stroke. This putter has an elongated shaft of 40 to 50 inches. The overall length of the putter is somewhat longer due to the length of the head and counterweight. Florian uses a counterweight of an unspecified amount to locate the balance point of the club generally midway between the head and the end of the handle.
Spoonster, in U.S. Pat. No. 4,869,511, describes a heavy training device that is added and removed from around the grip of a standard club. This device is used during practice to help train a golfer's muscles while swinging at a slower speed. The heavy training device causes the golfer to swing the club at a slower speed enabling him to concentrate on each muscle movement analyzing them for defects.
In U.S. Pat. No. 6,364,787, Huiskamp discloses a method of counter weighting a club with 25 to 200 grams to provide an advantageous weight distribution which increases the moment of inertia but decreases the swing weight to allow a golfer to generate an increased velocity.
Finally, in U.S. Pat. Nos. 5,632,691 and 5,554,078, Hannon in an attempt to produce a putter that helps a golfer obtain a positive wrist-lock, discloses a putter that has a predetermined amount of weight added to a predetermined location along the shaft and a putter head that has a predetermined weight substantially less than the weight of a conventional putter head. Hannon states that the range of weight for his invention is dependant on the weight of the putter head; 100 grams for a 240 gram putter head up to 570 grams for a 320 gram putter head. Additionally, the center of the weight means is placed at a distance from the buttend of the shaft between 20 and 71.4 length % of the overall length of the club (or between 7 and 25 inches from the end of a 35 inch long golf putter. This results in a balance point for the entire club located between 44 and 65 percent of the total length of the club as measured from the butt end. This would fall between 15.4 and 22.75 inches from the butt of the club. The preferred embodiment is a putter head weighing 240 grams and an added weight of about 100 grams. This results in a balance point for the club to be 21.38 inches from the butt end of the club. A different embodiment describes a 320 gram putter head using a 570 gram weight. This results in a balance point for the putter at 23.19 inches from the butt end of the club. Hannon states that “optimum” results are achieved using 290 grams of additional weight and a 320 gram putter head.
While much of the prior art focuses on adding weight to the club in various fashions in order to shift the balance point, change the swingweight, or improve the feel, none of the art specifically teaches about the gravity effect or attempts to address this problem by eliminating the gravity effect associated with conventional putters when swung through an angle. This effect is there because in a conventional putting stroke the putter is swung about a point between the shoulders as a unit, no rotation about the wrists is desirable. When the putter is swung in this manner there exists forces that are imparted on the golfer's hands that are a function of the product of the weight of the club times the distance between the center of gravity of the club and the center of the golfers grip and the angle of the club past vertical. In actuality, the inventions described by Hannon and Spoonster would only increase the effect of gravity as sensed by a golfer's hands due to the amount and location of the weight being added to the club. Neither of these inventions recognizes that the only way to eliminate these undesirable forces is to move the center of gravity into the grip area where a golfer can place the midpoint of his two handed grip at the center of gravity of the club thus driving the distance from the center of grip to the center of gravity of the club to zero. With the distance between the center of gravity of the club and the center of grip being zero the product of zero and the total weight of the club is still zero regardless of the total weight of the club. Both Spoonster and Hannon use large amounts of weight to move the center of gravity of the club closer to the grip. However, by adding large amounts of weight and not moving the center of gravity into the grip area where the golfer can drive the distance between the center of gravity and the center of his grip to zero they are left with forces that are the product of several inches times a club that is several times heavier than a conventional club. The net result is a club that is no better than and is typically worse than a conventional putter with no counterweights. The remainder of the art discussed above would generally do nothing to reduce the gravity effect based on the location of the weight in the grip or the small amounts of weight located at the end. Much of the prior art uses a counterweight to change the swing weight of the club. distribution of a golf club.
The present invention describes a putter that when swung through an angle maintains a zero acceleration force due to gravity in the direction of motion of the putter about a location within the grip area regardless of the angle of the putter along its swing path. This is accomplished by adding a relatively heavy counterweight above the grip area of the handle so as to move to the center of gravity into the grip area of the handle allowing a golfer to place the center of his grip at the center of gravity of the club.
It is, therefore, an aspect of the present invention to provide a golf putter that greatly improves the golfer's feel for the acceleration being imparted to the club in the direction of motion by allowing the golfer to eliminate the undesirable moments sensed by the hands and wrists due to gravity acting on the club as it is swung through an arc.
Other aspects of this invention will appear from the following description and appended claims, reference being made to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
In the traditional putter, the typical club head weighs 320 grams, a standard steel shaft weighs 100 grams and the grip weighs 60 grams. The grip is placed on one end of the shaft and the club head at the other extreme. Over the years the weight of the putter head has remained at roughly 320 grams plus or minus 10 percent. If the putter head became too heavy it would be difficult to swing and a golfer's ability to control distance would be compromised. If the club head became too light it would have to be swung at a quicker pace to generate the energy to roll the ball a given distance. The quick pace required of a light putter does not promote a smooth tempo to the swing that is critical to a good putting stroke.
As stated earlier, the best putting strokes are smooth pendulum motions. The club is swung about a point that lies between the shoulders. The golfer initiates the stroke by swinging the club head back 10 to 20 degrees, stops the club and then attempts to apply a constant acceleration to the club until after striking the ball. Once the ball has been struck the golfer brings the club to a stop to complete the stroke.
The hands are placed on the grip of the putter near the end of the shaft. Since the hands are the only contact the golfer has with the club, it is the hands that sense the accelerations that are being imparted to and acting on the club. When the golfer addresses a ball to prepare to putt, the putter is substantially vertical when looking directly at the front of the golfer.
As the golfer swings the club backward, an angle is developed between the club and the direction of gravity. The forces of gravity acting on the club head and shaft begin to generate a moment about the hands. This moment is in the same plane as the moment created by the acceleration of the club thus either adding to or subtracting from the moment due to acceleration. Additionally, the moment generated by the forces of gravity acting on the club head and shaft continue to increase as the angle increases in the back swing. If the golfer is to achieve a constant acceleration of the club on the critical forward stroke, he must continually compensate for forces of gravity he is sensing and adjust his swing to account for what he is feeling. This makes developing a consistent, fluid and repeatable stroke very difficult to achieve.
In order to resolve this issue it is necessary to design a putter to have the center of gravity located within the grip area of the club. Once the center of gravity is located in the grip the golfer can place his hands at the center of gravity of the club. If a golfer's hands are placed on the center of gravity of the club all the moments associated with gravity have been eliminated. The golfer only senses the moments created by his desire to accelerate the club a given amount. Since the golfer only senses the acceleration of the club in the direction of motion he is able to develop a much better “feel” for distance and reduce errors created by not compensating properly for the forces of gravity.
In order to move the center of gravity of the club into the grip, a substantial counter weight must be attached to the end of the shaft above the grip. Since the counter weight is above the grip it can be made large enough to counter the moments created by the shaft and club head due to gravity. Once the club is balanced in this fashion and the hands placed at the center of gravity of the club, now located along the grip, the moments acting on the hands and wrists due to gravity are eliminated. This is true regardless of the angle between the club and gravity or the total weight of the club. Thus an advancement in the art is created by having a putter that when swung through an angle maintains an acceleration force due to gravity in the direction of motion of the putter about a location within the grip area of zero regardless of the angle of the putter along its swing path.
Much of the prior art describes the use of weight to improve the feel of a club. Most of these disclosures are designed to improve the feel of irons and woods used to strike the ball long distances. For these clubs only small amounts of weight can be used since large amounts would render the club useless. Since the putting stroke is very different, large amounts of weight can be added to the putter. Several patents have described adding somewhat larger weights specifically to putters, however, these are not attempting to move the center of gravity into the grip. When weight is added under the grip near where the hands are placed no counter balancing effect is achieved. While the center of gravity of the entire club has moved, the moments sensed by the hands due to gravity acting on the club and shaft are not countered by an equal and opposite moment acting on the hands due to the counter-weighting scheme chosen. This is true since the amount of weight and its placement described in these other inventions does not even come close to achieving the desired result of moving the center of gravity of the club into the grip.
In order to move the center of gravity of a putter using a standard steel shaft and a 320 gram head into the grip area, a weight of about 1200 grams would be required to be placed above the grip. The exact amount of weight used to accomplish this effect can vary depending on the weight of the club head and shaft as well as just how far up into the grip the center of gravity is moved. In order to allow a golfer to place the center of his two handed grip at the center of gravity of the entire club the center of gravity of the club should be moved at least 2 inches into the grip area. In addition, the overall length of the entire club has a significant effect on parameters used to move the center of gravity into the grip. Putters designed for use with a pendulum putting stroke can range from 31 to 40 inches long. In this manner, shorter players can use a short club and taller players can use a somewhat longer putter to facilitate proper posture for the putting stroke. Because of this length difference, the exact distance the center of gravity will be located from either the proximal grip end or the distal head end will vary. Typically, the center of gravity will fall between 20 to 30 inches up from the head end. This will allow most golfers of average size to take a comfortable stance, with proper posture and still place the center of their two handed grip on the center of gravity of the club. The preferred embodiment would place the center of gravity of the entire club at a location between 4 and 12 inches from the center of gravity of the counterweight. This relationship holds for putters between 31 and 40 inches long.
It is, therefore, seen that the present invention of moving the center of gravity of a putter into the grip area by placing a counter-weight of sufficient mass above the grip to balance the head and shaft will allow a golfer to eliminate the unwanted gravity effects sensed by the golfer's hands and wrists. This concept creates a new putter that when swung through an angle maintains an acceleration force due to gravity in the direction of motion of the putter about a location within the grip area of zero regardless of the angle of the putter along its swing path.
For additional objects and advantages, as well as for a fuller understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.
The accompanying drawings illustrate complete preferred embodiments of the present invention according to the best modes presently conceived for the practical application of the principals thereof, and in which:
Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
Referring now to
This is contrasted to the putter of this invention shown in
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other equivalent modifications or changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in and limited solely by the appended claims.
Although the present invention has been described with reference to preferred embodiments, numerous modifications and variations can be made and still the result will come within the scope of the invention. No limitation with respect to the specific embodiments disclosed herein is intended or should be inferred.
