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Publication numberUS20060019765 A1
Publication typeApplication
Application numberUS 10/455,998
Publication dateJan 26, 2006
Filing dateJun 6, 2003
Priority dateJun 6, 2003
Publication number10455998, 455998, US 2006/0019765 A1, US 2006/019765 A1, US 20060019765 A1, US 20060019765A1, US 2006019765 A1, US 2006019765A1, US-A1-20060019765, US-A1-2006019765, US2006/0019765A1, US2006/019765A1, US20060019765 A1, US20060019765A1, US2006019765 A1, US2006019765A1
InventorsDaniel Plutt
Original AssigneePlutt Daniel J
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Gravity compensated golf putter
US 20060019765 A1
Abstract
An improved design for a golf putter is described based on the principal of eliminating the moments due to gravity acting on the club as sensed by the hands. The design uses a large counter weight attached to the shaft located above the grip area of the club. The counter weight is of sufficient mass to move the center of gravity of the entire club into the grip area of the putter. Once the center of gravity of the entire club is located in the grip near where the hands are placed, the undesirable moments generated by gravity during the swing are eliminated. The golfer only senses the forces associated with accelerating the club in the direction of motion. By eliminating the moments due to gravity an improved putter design is achieved since the golfer's feel for the acceleration of the putter is greatly improved.
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Claims(21)
1. A golf 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 the swing path.
2. The golf putter of claim 1, comprising a counter weight of 600 to 1800 grams located above the grip area.
3. The putter of claim 1 wherein the center of gravity of the entire club is located at least 2 inches into the grip area as measured from the head end.
4. The golf putter of claim 1 further comprising a putter length of about 31 to 40 inches
5. The golf putter of claim 1, wherein the center of gravity of the entire club is at a location between 4 and 12 inches from the center of gravity of the counterweight.
6. The putter of claim 3, wherein the center of gravity of the putter is located substantially at the center of the grip area.
7. The putter of claim 1 that has a visual indicator in the grip area to mark the center of gravity of the club
8. The golf putter of claim 2, wherein the counter weight further comprises a covering forming a blend with the grip area.
9. A golf putter comprising:
a shaft having a head fixed at one end and a grip fixed toward an opposite end (grip end);
the grip comprising an area for the golfer's two hands to be placed on the club; and
a counter weight means of sufficient mass located above the grip functioning to place a center of gravity of the entire putter inside the grip area.
10. The golf putter of claim 9, wherein the overall length of the putter is 31 to 40 inches.
11. The golf putter of claim 9, wherein the head weighs between 260 and 360 grams, and the counter weight weighs between 600 and 1800 grams.
12. The golf putter of claim 9, wherein the center of gravity of the entire club is at a location between 4 and 12 inches from the center of gravity of the counterweight
13. The golf putter of claim 9, wherein the location of the center of gravity is at least 2 inches into the grip area as measured from the head end.
14. The golf putter of claim 13 wherein the center of gravity of the entire club is located substantially at the center of the grip area.
15. The golf putter of claim 9, wherein the grip area contains an indicator to mark the center of gravity of the club.
16. A golf 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 the swing path. The putter comprising:
a head at a head end;
a shaft extending upward from the head when the club is in a playing position;
a grip encircling the shaft;
and a counter weight means of sufficient mass located above the grip functioning to place a center of gravity of the entire putter inside the grip area.
17. The golf putter of claim 16, wherein the center of gravity of the entire club is at a location between 4 and 12 inches from the center of gravity of the counterweight.
18. The golf putter of claim 16, wherein the location of the center of gravity is at least 2 inches into the grip area as measured from the head end.
19. The putter of claim 16 that has a visual indicator in the grip area to mark the center of gravity of the club.
20. The golf putter of claim 16, wherein the overall length of the putter is 31 to 40 inches.
21. The golf putter of claim 16, wherein a covering covers both the counter weight and the grip.
Description
FIELD OF INVENTION

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”.

BACKGROUND OF THE INVENTION

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.

SUMMARY OF THE INVENTION

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.

BRIEF DESCRIPTION OF THE 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:

FIG. 1 (prior art) is a plan view of a conventional putter showing the center of gravity of the various components.

FIG. 2 is a plan view of the putter of the preferred embodiment of this invention showing the center of gravity of the various components.

FIG. 3 is a static force diagram of the conventional putter depicted in FIG. 1 at the start of a golfer's forward stroke.

FIG. 4 is a graph representing the moments exerted on the hands of a golfer swinging the conventional putter of FIG. 1 as a function of angle and separated by gravity component and forward acceleration component.

FIG. 5 is a graph representing the combined moments due to gravity and forward acceleration exerted on the hands of a golfer swinging a conventional putter depicted in FIG. 1 as a function of angle.

FIG. 6 is a static force diagram of the putter of this invention depicted in FIG. 2 at the start of a golfer's forward stroke.

FIG. 7 is a graph representing the moments exerted on the hands of a golfer swinging the putter of this invention depicted in FIG. 2 as a function of angle and separated by gravity component and forward acceleration component.

FIG. 8 is a graph representing the combined moments due to gravity and forward acceleration exerted on the hands of a golfer swinging the putter of this invention depicted in FIG. 2 as a function of angle.

FIG. 9 is a cross-sectional view of the grip end of the putter of this invention depicting the location of the counter weight.

FIG. 10 is cross-sectional view of the grip end of the putter of this invention depicting the location of the counterweight. The counterweight is covered with a similar material as the grip to create a continuous appearance.

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.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1 of the drawings, the construction of a conventional putter 1000 is shown with the center of gravity of its various components depicted. The conventional putter has a club head 12 with its respective center of gravity 10, a shaft 16 with its respective center of gravity 14 and a grip 20 and it's respective center of gravity 18. Additionally, the center of a golfer's grip coincides with the center of gravity of the grip 18. Since the majority of the weight of the club is located in the head 12 the combined center of gravity 8 for the entire club is located well down the shaft near the head.

This is contrasted to the putter of this invention shown in FIG. 2. The new putter 2000 also has a head 22 with its respective center of gravity 24, a shaft 28 with its center of gravity 26 and a grip or grip area 32 with its center of gravity 30. Additionally, this club has a counterweight 36 with its center of gravity 34 located above the grip 32. The counter weight is of sufficient mass to move the center of gravity for the entire club 2000 away from the club head 22 and place it at the center of the grip 32 at point 30. The grip could have a visual indicator at point 30 to show where the center of gravity of the club is located to help a golfer place his hands on the correct point. The benefits of moving the center of gravity of the entire club to the center of the grip point of the club become understandable when looking at FIGS. 3 through 8. While the center of gravity of the club is ideally located at the center of the grip area it should be located at least 2 inches into the grip area as measured from the head end to allow a golfer to place both hands around the center of gravity and still be on the grip.

FIG. 3 is a static force diagram of the putter of FIG. 1 at the end of the back swing as the golfer is beginning to accelerate the club for the forward stroke. For the desired putting stroke the putter is swung in a pendulum fashion around a point between the shoulders 50. In order to determine the moment being exerted on a golfer's hand and wrists throughout the stroke one only needs to sum the moments about the center of grip 18. The force diagram shows that the magnitude of the gravity force acting on 18 due to the head 12 is a function of the weight of the head, SIN of the angle 71, and the length d(head) from the center of grip 18. The moments at the center of grip due gravity acting on the shaft, 16, are similar, they are a function of the weight of the shaft, the SIN of the angle 71 and the distance from the center of grip d(shaft). Additionally, moments are generated by the constant acceleration of the club the golfer is trying to achieve. These moments about the center of grip 18 are a function of the mass and acceleration of the head times the distance from the center of grip l(head). The shaft also exerts a moment that is a function of the mass of the shaft and acceleration of the shaft times the distance, l(shaft) from the center of grip 18.

FIG. 4 is a graphical representation of the two primary effects creating moments sensed by a golfer gripping the club at the center of grip point 18. There is a combined gravity moment due to the shaft and head that is a function of the SIN of the angle. This is shown by the line 60. It can be seen in the graph that the greater the angle the grater the magnitude of this effect. At a zero angle, the club is vertical, the magnitude of this component is zero. Additionally, this component reverses direction as the club is swung to the other side of vertical. The component of moments due to the acceleration of the club is represented by line 62 on the graph. Since the golfer is trying to achieve a constant acceleration into the ball during the forward stroke this component is constant until past the zero angle point when the golfer begins the transition into a deceleration phase of the stroke thus the change in sign of this component after zero angle.

FIG. 5 is a representation of the summation of the moments sensed by a golfer with hands placed about the center of grip 18 due to gravity and the acceleration of the club. Viewing line 64 it is shown that while a golfer is trying to achieve constant acceleration the feedback received by his hands located about the center of grip 18 is anything but constant. Since the moments due to gravity acting on the golfers hands are a function of the SIN of the angle of the club with respect to vertical, the golfer senses continually changing forces. If a constant acceleration is to be achieved a golfer must somehow continually compensate for the forces due to gravity he senses. A secondary compounding factor is that while the forces due to gravity are only a function of the weight of the club and the SIN of the angle, the forces due to acceleration are a function of the acceleration of the club and the weight of the club. Therefore, if the club is accelerated at a slower rate, the gravity forces become a greater percentage of the total moments sensed, if club is accelerated at a greater rate the gravity forces are a smaller portion of the moments sensed.

FIGS. 6 through 8 are similar diagrams as described above but contrast the moments of the putter of this invention. The putter 2000 eliminates the moments sensed by the golfer holding the club at the center of grip at point 30. In FIG. 6 all the same components are present as previously described. The moments about the center of grip 30 due to gravity are a function of the weight of the head 22, the SIN of the angle 71 and the distance from the head d(head) as well as the weight of the shaft 28 the, SIN of the angle 71 and the distance from the center of grip d(shaft). While these two components are the same as for FIG. 3 one additional component has been added. This is the counter weight 36. The counter weight is designed to fully balance the effects of gravity acting on both the head and shaft. Therefore, it is placed above the grip point and has sufficient mass when multiplied by the SIN of the angle 71 and the distance from the center of grip d(cw) a net zero effect is achieved. This can be seen by investigating FIG. 7. It will be noted that the line 90 depicting the moments due to gravity acting on the hands located at the center of grip 30 is a line located a zero. This is true no matter the angle of 71. The forces due to constant acceleration are represented by line 92. The shape of the line is exactly the same as in the FIG. 4 however the absolute value has changed slightly for a given acceleration due to the addition of the force due to the counterweight 36 acting at a distance l(cw) from the center of grip. Viewing the combined force graph of FIG. 8 line 94 is identical to line 92 in the previous graph. This is due to the moments due to gravity being zero. It can be seen from these graphs that the moments the golfer senses are entirely a function of the acceleration he is trying to achieve and not the continually changing moments due to gravity. By eliminating the moments due to gravity it is much easier for a golfer to develop a “feel” for a consistent, repeatable stroke.

FIG. 9 is a cross sectional view of the grip end of the putter of this invention. The putter consists of a shaft 28, grip 32 and counter weight 36 attached to the shaft. The counter weight is of sufficient mass to place the center of gravity of the entire club at location 30, at point within the grip area. In this embodiment the counter weight shown is 5.5 inches long, 1.375 inches in diameter and made of brass, although many other materials could be used such as lead or steel as well as other cross sections such as oval, square or rectangular. This produces a weight of 1185 grams, sufficient to move the center of gravity of the entire club into the grip area. Given the amount of weight needed to place the center of gravity in the grip area it may be placed outside the shaft as shown. It may also be placed primarily above the grip. In this example counter weight 36 is left exposed above the normal gripping area and may be contoured to the shape of the grip to facilitate a smooth transition between the grip and the counterweight.

FIG. 10 shows an alternative embodiment. Again, the counterweight 36 is connected to the shaft 28. The counter weight 36 is of sufficient mass to move the center of gravity of the entire club to location 30, inside the grip area of the club. The same dimensions as stated earlier apply to this counter weight. However, in this design, the grip 32 is extended into area 320 to cover the counter weight 36. This would be done to hide the weight, or make a continuous surface at the end of the handle. It does accomplish the same goal of placing the center of gravity of the entire club in the grip area of the putter. A golfer need only to place his hands several inches below the counter weight to eliminate the undesired effects of gravity. While the center of gravity of the club is ideally located at the center of the grip area it should be located at least 2 inches into the grip area as measured from the head end to allow a golfer to place both hands around the center of gravity and still be on the grip.

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.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7371187 *Mar 14, 2005May 13, 2008Sri Sports LimitedGolf putter and method of designing the same
US7416129Mar 19, 2007Aug 26, 2008Symbol Technologies, Inc.Mobile terminal with ergonomic housing
US7485048 *Aug 15, 2003Feb 3, 2009Devilray AsGolf club device
US7562824 *Jan 4, 2007Jul 21, 2009Symbol Technologies, IncMobile terminal with ergonomic housing
US20110159982 *Dec 20, 2010Jun 30, 2011Hiroyuki TakeuchiGolf club
US20140004970 *Dec 8, 2011Jan 2, 2014Keun Shik ChangGolf club having dynamic center of gravity portions for golf swing, formed at the position of a shaft fixed beneath a grip
Classifications
U.S. Classification473/297, 473/313, 473/340
International ClassificationA63B53/04, A63B53/02, A63B53/14
Cooperative ClassificationA63B53/145, A63B53/007
European ClassificationA63B53/00P