Nike had an interesting patent application publish today. I say “interesting” because my first thought was “that’s ridiculous, how would knowing precisely where the center of gravity is located for each of my irons help a hack like me play better.” However, the more of the application I read, the more I liked the concept. Decide for yourself.

The application published as US Pub. No. 20100255923 titled “Golf Clubs and Golf Club Heads,” which describes the invention as:

Golf club heads which include an iron type golf club head body including a ball striking face, a rear surface opposite the ball striking face (e.g., including a perimeter weighting member) and an indicator which indicates the location of the center of gravity of the golf club head body. Golf  clubs including these club heads and methods of making such golf club and golf club heads also are provided.

The application goes on to explain:

[0002] Golf is enjoyed by a wide variety of players--players of different genders and dramatically different ages and/or skill levels. Golf is somewhat unique in the sporting world in that such diverse collections of players can play together in golf events, even in direct competition with one another (e.g., using handicapped scoring, different tee boxes, in team formats, etc.), and still enjoy the golf outing or competition. These factors, together with the increased availability of golf programming on television (e.g., golf tournaments, golf news, golf history, and/or other golf programming) and the rise of well known golf superstars, at least in part, have increased golf's popularity in recent years, both in the United States and across the world.

[0003] Golfers at all skill levels seek to improve their performance, lower their golf scores, and reach that next performance "level." Manufacturers of all types of golf equipment have responded to these demands, and in recent years, the industry has witnessed dramatic changes and improvements in golf equipment. For example, a wide range of different golf ball models now are available, with balls designed to complement specific swing speeds and/or other player characteristics or preferences, e.g., with some balls designed to fly farther and/or straighter; some designed to provide higher or flatter trajectories; some designed to provide more spin, control, and/or feel (particularly around the greens); some designed for faster or slower swing speeds; etc. A host of swing and/or teaching aids also are available on the market that promise to help lower one's golf scores.

[0004] Being the sole instrument that sets a golf ball in motion during play, golf clubs also have been the subject of much technological research and advancement in recent years. For example, the market has seen dramatic changes and improvements in putter designs, golf club head designs, shafts, and grips in recent years. Additionally, other technological advancements have been made in an effort to better match the various elements and/or characteristics of the golf club and characteristics of a golf ball to a particular user's swing features or characteristics (e.g., club fitting technology, ball launch angle measurement technology, ball spin rates, etc.).

[0006] The following presents a general summary of aspects of the disclosure in order to provide a basic understanding of the disclosure and various aspects of it. This summary is not intended to limit the scope of the disclosure in any way, but it simply provides a general overview and context for the more detailed description that follows.

[0007] Golf club heads according to at least some example aspects of this disclosure include: an iron-type golf club head body having a ball striking face and a rear surface opposite the ball striking face (e.g., including a perimeter weighting member extending rearward from the ball striking face and along at least a portion of a circumferential area of the golf club head body). Also, the golf club head body may include an indicator. Further, in accordance with at least some examples of this disclosure, the indicator may indicate the precise location of the center of gravity of the golf club head.

[0008] A set of golf club heads in accordance with at least some examples of this disclosure may include club head bodies that have varying centers of gravity depending on the particular club head body. In such golf club head bodies, the indicators may be positioned to indicate the location of the center of gravity for each respective club head body.

[0009] According to some aspects of this disclosure, the positioning of the indicator can be used to alter the center of the gravity of the club head body. For example, due to the indicator's weighting characteristics (weight, density, etc.), the position of the indicator with respect to the club head body will redistribute the weight of the golf club head body and thereby shift the club head body's center of gravity. Therefore, the indicator can be selectively positioned to control features of the club head's center of gravity.
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[0022] As described above, aspects of this disclosure relate to iron-type golf club heads and golf clubs. Iron-type golf club heads according to at least some example aspects of this disclosure may include: (a) an iron-type golf club head body; (b) a ball striking face; (c) a rear surface opposite the ball striking face, optionally including a perimeter weighting member extending rearward from the ball striking face and along at least a portion of a circumferential area of the golf club head body; and (d) an indicator.

[0023] According to aspects of this disclosure, the indicator may indicate the location of the center of gravity of the golf club head body. Therefore, according to such aspects of this disclosure, in a set of golf clubs wherein each golf club head body has a different center of gravity, the indicator for each golf club head body may be different (e.g., differently shaped) and/or differently positioned in order to reflect the different location of the center of gravity of each particular golf club head body in the set. For example, because the center of gravity of a golf club head body for a pitching wedge may be different that the center of gravity of a golf club head body for a 5-iron, the indicator for the pitching wedge will indicate a location which is different from the location indicated by the indicator on the 5-iron.

[0024] According to aspects of this disclosure, the indicator itself (or the indicator portions which make up the indicator) may affect the location of the center of gravity of the golf club head body. For example, the weight of the indicator may affect the location of the center of gravity of the golf club head body. Further, the indicators may have different weights, different densities, different weight distributions, and/or other different weighting characteristics relative to the rest of the club head body. Therefore, according to such aspects of this disclosure, the indicator may be positioned so that it will alter the center of gravity of the club head body. In other words, the positioning of the indicator relative to the club head body can be controlled in order to provide a particular center of gravity for a golf club head body. As described below, providing a particular center of gravity for a golf club head body can be advantageous.

[0025] According to some aspects of this disclosure, the indicator may be positioned in "long" iron type golf clubs (i.e., irons with a relatively low degree of loft, e.g., a 3-iron) to provide a center of gravity of the golf club head body which is closer to the heel of the club head body (i.e., near the hosel). Such a configuration decreases the distance from the hosel to the center of gravity of the golf club head body. Because the center of gravity is closer to the hosel, the golfer can more quickly and easily rotate the golf club head body (e.g., from an open club face position to a closed club face position). Hence, such a configuration can aid a golfer in imparting "draw" trajectory to the golf ball. A "draw" is a golf shot in which the golfer curves the ball in a direction opposite to the side from which it was struck. For example, for a right handed golfer, the golf ball will have "right to left" trajectory. The ball flight for a "draw" tends to have less back spin and, therefore, the ball tends to roll further once it lands. Also, "draws" tend to exhibit lower ball flights. These aspects of a "draw" (i.e., less back spin, further roll and lower ball flight) tend to increase the distance that the golf ball will travel upon being struck by the golfer. Therefore, providing the center of gravity of the golf club head body near the heel can increase the distance of a golf shot, which may be particularly useful in "long" irons.

[0026] According to some other aspects of this disclosure, the indicator may be positioned in "short" iron type golf clubs (i.e., irons with a relatively high degree of loft, e.g., a 9-iron, wedges, etc.) to provide a center of gravity of the golf club head body which is closer to the toe of the club head body. Such a configuration increases the distance from the hosel to the center of gravity of the golf club head body. Because the center of gravity is further away from the hosel, the golfer cannot rotate the golf club head body as quickly or easily (e.g., from an open club face position to a closed club face position). Therefore, the stability of the golf shot is increased. Hence, such a configuration can aid a golfer in imparting "fade" trajectory to the golf ball. A "fade" is a golf shot in which the golfer curves the ball a direction corresponding to the side from which it was struck. For example, for a right handed golfer, the golf ball will have "left to right" trajectory. The ball flight for a "fade" tends to have more back spin and, therefore, the ball tends to roll less once it lands. Also, "fades" tend to exhibit higher ball flights. These aspects of a "fade" (i.e., more back spin, less roll and higher ball flight) tend to stop the ball from rolling. Therefore, providing the center of gravity of the golf club head body near the toe can aid the golfer in stopping the ball from rolling when it lands on the green, which may be particularly useful in "short" irons.

[0027] According to some other aspects of this disclosure, the indicator may be positioned in "middle" iron type golf clubs (i.e., irons with a relatively intermediate degree of loft, e.g., a 5-iron) to provide the center of gravity of the golf club head body generally near the center of the club head body. Such a configuration can create a relatively intermediate distance from the hosel to the center of gravity of the golf club head body. Because the center of gravity is at a relatively intermediate distance from the hosel (e.g., near the center of the golf club head body) the "middle" irons will have some characteristics from each of the above described "long" and "short" irons (e.g., further distance and better ball control), but not to the same extent.
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[0040] Further, according to aspects of this disclosure, the golf club head body 102 may include an indicator 204 which indicates the golf club head body's center of gravity denoted symbolically at reference numeral 205. For example, according to some aspects of this disclosure, the indicator 204 may be either a portion of the perimeter weighting member 202 of the golf club head body 102 or a separate element(s) (e.g., made from the same or different materials as the perimeter weighting member) that is attached to the perimeter weighting member 202. In such structures the indicator 204 may be positioned at least along the top, bottom or side portions of the perimeter weighting member 202 and may form a substantial portion of at least one of the top, bottom or side of the perimeter weighting member 202. In the depicted embodiment, the indicator 204 extends from the perimeter weighting member 202 into the cavity 206 in the rear portion of the club head body 102 and has three points of contact with the perimeter weighting member 202. Further, as seen in the depicted embodiment the indicator is shaped like an arrow. The arrow points towards the golf club head body's center of gravity 205 and specifically, according to some aspects of this disclosure, the arrow will point to the precise location of the golf club head body's center of gravity 205. This allows the golfer to actually see the position of the center of gravity for each golf club head body in the set (e.g., during practice). Hence, when the golfer uses the golf club (e.g., during a round), the golfer will know that the center of gravity for each golf club body in the set is correct (i.e., in the correct position). This is useful for a golfer when choosing a club from his golf bag for a particular golf shot, because in addition to a number or letter that is typically imprinted on the sole of the club head body to identify the golf club, the above described indicator provides additional confirmation that the correct club was chosen.

[0041] Of course the indicator 204 need not be shaped like an arrow and instead other embodiments of the indicator 204 could be employed. For example, instead of an arrow-shaped indicator, a solid, triangular shape could be used. Further, the indicators 204 need not be "pointed" (e.g., triangularly or arrow-shaped). For example, the indicators 204 may be curved, arched, rounded, multi-leveled, stepped, etc. Hence, it is realized that the specific structure of the indicator 204 may vary without departing from this disclosure. In fact, the indicator 204 need not have a structure at all. For example, instead of physical structures, colors or graphics (e.g., characters) may be employed. For example, a colored dot, arrow head, etc. could be imprinted or etched in the club head body 102 to reflect the center of gravity of the club head body 102. Hence, it is realized that as long as the indicator 204 reflects the location of the center of gravity of a particular golf club head body 102, it is considered within the scope of the disclosure.

[0042] According to some aspects of this disclosure, in a set of golf clubs wherein each golf club head body has a different center of gravity, the indicator 204 for each golf club head body 102 may be different (e.g., a differently shaped element) and/or positioned differently in order to reflect the different location of the center of gravity of each particular golf club head body in the set. For example, FIGS. 2A-C illustrate golf club head bodies of such a set of golf clubs. FIG. 2A is an illustrative embodiment of a golf club head body 102 for a "long" iron (e.g., a 3-iron), FIG. 2B is an illustrative embodiment of a golf club head body 102 for a "middle" iron (e.g., a 5-iron), and FIG. 2C is an illustrative embodiment of a golf club head body 102 for a "short" iron (e.g., a 9-iron). As can be seen by comparing FIGS. 2A, 2B and 2C, the different golf club head bodies each have a different center of gravity 205 and, further, the indicators 204 are positioned to reflect the respective centers of gravity 205 for the different golf club head bodies.

FIG. 2D schematically shows an entire progression of the indicator position around the circumference of the club head bodies in a set of golf clubs according to such an embodiment of this disclosure. As seen in FIG. 2D, the progression begins as a 2-iron (one of the club head bodies with a low degree of loft relative to the set of club head bodies) with the indicator 204 positioned generally at the heel end of the club head body 102. The progression continues successively in a counter clockwise fashion around the circumference of the club head body 102 from the heel through the center bottom portion of the club head body 102 and towards the toe of the club head body 102 until the progression ends as a pitching wedge (one of the club head bodies with a high degree of loft relative to the set of club head bodies) with the indicator 204 positioned at the upper toe end of the club head body 102. In this way, the indicator 204 of each golf club head body reflects the different center of gravity for each particular golf club head body 102 in the set of golf clubs. It is noted of course, that this is merely one embedment of a set of golf clubs according to this disclosure and other sets of golf clubs according to this disclosure may include other clubs, such as sand wedges, lob wedges, hybrids irons, etc.

[0043] It is noted that other desired progressions (e.g., counter clockwise from the toe around the crown of the club head body to the heel) or arrangements may be provided without departing from this disclosure. Also, it is noted that the arrangement of the indicators 204 does not necessarily require that the indicators 204 be positioned around the circumference of the club head body 102 (e.g., the indicators 204 may be completely within the cavity 206). Therefore, it is realized that the indicators 204 may be positioned or arranged in or around the golf club head bodies of a set of golf clubs in a variety of different manners, orientations, and the like without departing from this disclosure.

[0044] According to some aspects of this disclosure, in addition to merely indicating the location of the center of gravity of the club head body 102, the positioning of the indicator 204 can be used to alter (e.g., shift) the center of the gravity of the club head body 102. For example, due to the indicator's weighting characteristics (weight, density, etc.), the position of the indicator 204 with respect to the club head body 102 will redistribute the weight of the golf club head body 102 (as compared to the golf club head body without the indicator 204) and thereby shift club head body's center of gravity 205. Therefore, the indicator 204 can be selectively positioned to control features of the club head's center of gravity 205.

[0045] For example, according to some aspects of this disclosure, the indicator 204 may have a different weight, a different density, a different weight distribution, and/or other different weighting characteristics than the perimeter weighting member 202 or other portions of the club head body 102. For example, the indicator 204 may be made heavier as compared to the other parts of the golf club head (e.g., by including a weighted mass, such as lead or tungsten containing material, etc. in the indicator 204). Yet, according to some other aspects of this disclosure, the indicator 204 may have the same weighting characteristics (weight, density, etc.) as the perimeter weighting member 202 or other portions of the club head body 102. Further, it is noted that, different sections or portions of the perimeter weighting member 202 may also have a different weight, a different density, a different weight distribution, and/or other different weighting characteristics than other sections or portions of the perimeter weighting member 202. For example, the crown portion of the perimeter weighting member 202 may be less dense the sole portion of the perimeter weighting member 202. Regardless of whether the indicator 204 has the same or different weighting characteristics as the perimeter weighting member 202 (or at least portions of the perimeter weighting member 202) or other portions of the club head body 102, the indicator 204 can be still be selectively positioned to control features of the club head's center of gravity 205. Further, the shape or thickness of the indicator 204 can be varied to set the weight distribution as desired. For example, the structure of the arrow head or tail of the depicted indicator 204 can be modified in order to distribute the weight of the indicator as desired. In other words, one side of the arrow head could be formed so that it weighs more than the other side of the arrow head thereby shifting the center of the gravity of the club head body 102. Alternatively, or additionally, the tail could be shortened or lengthened thereby shifting the center of the gravity of the club head body 102.

[0046] Further, by positioning the indicator 204 around the circumference of the club head body 102 (e.g., as shown in FIG. 2D), the center of gravity of the club head body may be adjusted both vertically and horizontally. For instance, as mentioned above, FIGS. 2A-C illustrate the different locations of centers of gravity 205 for some different arrangements of the indicators 204 of the golf club head bodies. In the arrangement shown in FIG. 2A, the indicator 204 extends generally from the heel end of the club head body 102 towards the cavity 206. Therefore, the center of gravity 205 of this arrangement is closer to the heel of the club head body (e.g., closer to the heel than the toe). In contrast, as shown in FIG. 2C, the indicator 204 extends generally from the toe end of the club head body 102 towards the cavity 206. Therefore, the center of gravity of this arrangement is closer to the toe of the club head body 102 (e.g., closer to the toe than the heel). These different locations of the center of gravity 205 of the club head bodies can affect the trajectory and ball flight of a golf ball struck by the golf club.

[0047] Hence, it is understood that positioning indicators 204 (e.g., weighted indicators) in golf club head bodies according to the schematic shown in FIG. 2D can produce a set of golf clubs with desirable characteristics. For example, the configuration of FIG. 2A decreases the distance from the hosel to the center of gravity. Therefore, a "long" iron of such a set of golf clubs has a club head body with a center of gravity near the hosel. Hence, as discussed above, such "long" irons can aid a golfer in imparting a "draw" trajectory to the golf ball and, therefore, provide characteristics of a "draw" shot (i.e., less spin, further roll and lower ball flight) which will tend to increase the distance that the golf ball will travel upon being struck by the golfer. Conversely, the configuration of FIG. 2C increases the distance from the hosel to the center of gravity 205. Therefore, a "short" iron of such a set of golf clubs has a club head body with a center of gravity 205 near the toe. Hence, as discussed above, such "short" irons can aid a golfer in imparting "fade" trajectory to the golf ball and, therefore, provide characteristics of a "fade" shot (i.e., more spin, less roll and higher ball flight) which tend to provide enhanced ball control (e.g., stopping the ball on the green).

[0048] The weighting features of golf club heads in accordance with this disclosure are not limited to controlling the horizontal position of the golf club's center of gravity (the horizontal position when the golf club is oriented at a ball addressing position). Rather, the center of gravity in the vertical direction also may be selectively controlled, if desired, in at least some examples of golf club head structures according to this disclosure. Increasing the weight in the crown area of the club head (e.g., by providing a weighted indicator closer to the crown), produces a higher center of gravity in the golf club head which can provide a more boring golf ball flight path, e.g., for play in windy conditions, to provide more "running" shots, and/or to help compensate for swing flaws that typically produce an excessively high ballooning flight. Conversely, increasing the weight in the sole area of the club head (e.g., by providing a weighted indicator closer toward the sole), produces a higher center of gravity in the golf club head which can provide a more lofted golf ball flight path, which can help a golfer get the ball in the air.

[0049] According to some aspects of this disclosure, the indicator 204 can be positioned away from the face of the golf club head body 102. For example, the indicator 204 may be suspended from the heel, toe, sole or crown of the golf club head body 102. FIG. 2E shows a cross-sectional view of an illustrative embodiment of the disclosure wherein the indicator 204 is suspended from the sole of the golf club head body 102 and, therefore, positioned off of and away from the rear surface of the face of the golf club head body 102. By positioning the indicator 204 away from the face of the golf club head body 102, the center of gravity of the golf club head body 102 can be shifted away from the face of the golf club head body 102. In such an embodiment, it will be realized that the indicator 204 indicates the center of gravity by pointing to a point in space above the center of gravity. However, when viewed straight on from an angle such as seen in FIGS. 2A-C, the indicator will, in fact, point to the center of gravity. Of course, according to some aspects of the disclosure the indicator 204 could be angled toward or away from the rear surface of the club head body 102.

[0050] Therefore, it can be seen that selectively positioning of the indicator 204 relative to the golf club head body 102 affects the center of gravity of the golf club head. In this way, when the indicator portion 204 is positioned at particular locations around the golf club head body 102, the indicator 204 alters the weight distribution of the golf club head body 102 to move the club head body's center of gravity 205 to a desired position. Additionally, it can be seen that according to aspects of this disclosure, the indicator 204 can both indicate the precise position of the center of gravity of the golf club head body and, also, if desired, be selectively positioned to shift the weight of the golf club head body 102 in order to move the club head body's center of gravity 205 to a desired position.

Wait just one second.... "to help compensate for swing flaws that typically produce an excessively high ballooning flight." You mean to tell me that my excessively high ballooning flight is due to a swing flaw! Nonsense.

So, is this just another method of adjustability that no one uses past the first week, or does this concept have legs? Only time will tell, but first it has to make it into an actual commercial product.

David Dawsey   – The Golf Lawyer

PS – click HERE to read more posts about inventions and irons