Would Your Score Drop if You Tricked Yourself Into Thinking Your Clubs Had Larger Grooves?

[0005] The United States Golf Association (USGA) publishes and maintains the Rules of Golf, which govern golf in the United States. Appendix II to the USGA Rules provides limitations for golf clubs. Several of these rules are particularly relevant to the design of the grooves and the striking face. For example, the following USGA rules regulate the geometry of the grooves: grooves must be straight and parallel; grooves must have a plain symmetrical cross-section and sides which do not converge; the width, spacing and cross section of the grooves must be consistent throughout the impact area; the width of a groove cannot exceed 0.035 inch; the distance between edges of adjacent grooves cannot be less than three times the width of the grooves and not less than 0.075 inch; the depth of each groove cannot exceed 0.020 inch; the cross-sectional area of a groove divided by the groove pitch must not exceed 0.0030 in^2/in; grooves must not have sharp edges or raised lips; and groove edges must be substantially in the form of a round having an effective radius which is not less than 0.010 inch and not greater than 0.20 inch. Further, the surface roughness of the impact area cannot exceed that of decorative sandblasting or fine milling. The Royal and Ancient Golf Club of St Andrews (R&A), which is the governing authority for the rules of golf outside the United States, provides similar limitations to golf club design.

[0006] In 2008, the USGA announced the abovementioned new restrictions on groove design. Previous to 2008, the groove design rules were more lenient, which generally resulted in golf clubs, particularly wedges, with greater ball back-spinning capability. Under the pre-2008 rules, manufacturers generally used the same U-shaped groove design, with maximum allowable width, depth, volume, and number of grooves. Further, manufacturers generally utilized sharp radii on the edge of the grooves. The similar groove designs across the manufacturers were a direct result of consumer demand–golf club designers found that the maximum-sized grooves produced the greatest ball backspin.

[0007] However, as a result of the changes to the groove design rules, manufacturers are asked to stop manufacturing golf clubs that do not comply with the new groove design rules starting in 2011, but can sell inventory of these pre-2008 rules golf clubs through 2011. For golf professionals, they are required to compete using golf clubs compliant with the new groove rules as of Jan. 1, 2010. For amateurs, generally they may continue to use their pre-2008 rules golf clubs through 2024, after which they will be required to use golf clubs that conform to the new groove design rules. However, amateurs may be impacted as early as 2011, due to the likely unavailability of pre-2008 rules golf clubs, since manufacturers will likely stop manufacturing golf clubs that have grooves according to the old groove design rules, and will likely only sell golf clubs having grooves conforming to the current groove design rules.

SUMMARY OF THE INVENTION

[0008] Golfers generally prefer iron golf clubs, particularly wedges, to be designed to produce the maximum of ball backspin. Generally, a large amount of ball backspin producing capability is desired for wedges, which are high lofted iron clubs (e.g., 45 degrees to 70 degrees loft angle). The large amount of ball backspin in a short distance golf shot (e.g., 5 to 100 yards) generally results in the golf ball taking a slightly lower trajectory, and stopping in a short distance upon hitting the ground, especially in soft turf conditions. In comparison, a golf club that does not produce a large amount of ball backspin results in a golf shot that has a higher trajectory, and which rolls a considerable distance beyond the point where it first hits the ground (“roll-out”). For many golfers, backspin is highly desirable for situations requiring a precise landing zone. For example, in a situation where the pin is located in a narrow portion of the green (and surround by hazards), a golf shot with large amounts of backspin is desirable because the golfer only has to consider where to land the ball, and the backspin will cause the ball to remain where it landed. In comparison, if the golfer used a wedge incapable of producing high amounts of backspin, the golfer would likely have to land the ball well before the pin, perhaps even before the green, which may result in a short shot that falls into a near-side hazard. If the golfer lands the ball on the green, the ball may roll away and trickle into a far-side hazard because of the lack of ball backspin preventing roll-out.

[0009] Further, if the golfer is highly skilled, the golfer’s swing in combination with a high backspin producing wedge may cause the golf ball to land on the green, and then reverse course. Reversing course with the golf ball is desirable in situations where the golfer is short-sided, (i.e., the pin is very close to the edge of the green closest to the golfer, such that there is little distance between the start of the green and the pin, when measured in the distance and direction from the golfer to the pin). When short-sided, if the golfer can produce enough backspin for the ball to reverse course, the golfer then has the benefit of landing the ball anywhere behind the pin, and the ball will reverse course and roll backwards towards the pin. Without the ability to produce sufficient backspin to reverse course, the only recourse is for the golfer to land the ball short of the pin, hopefully without falling into a near-side hazard–otherwise, if the golfer lands the ball on the green, it will likely roll-out and roll well past the pin. Thus, it can be seen that a high ball backspin producing wedge is desirable for accuracy, in causing the ball to remain (“stick”) approximately where it lands (or reverse course).

[0010] Various groove geometries, materials, and surface finishes have been implemented in order to achieve greater ball backspin on iron golf clubs, especially for wedges. With respect to groove geometries, a larger groove width and a larger groove depth generally results in greater ball backspin. Larger groove volume also generally results in greater ball backspin. Groove geometries where the radius between the groove side wall and the golf club striking face is small and sharp generally results in greater ball backspin. With respect to materials, softer materials including elastomeric ones generally create greater ball backspin. With respect to surface finishes, with a rougher finish, generally the result is greater ball backspin. These design differences achieve greater ball backspin by generally either increasing the friction between the ball and the golf club, or by reducing the interference of friction-reducing artifacts, such as channeling away water and debris using large volume grooves.

[0011] However, as discussed above, the USGA and R&A rules limit the design of grooves and surface finishes for golf irons and wedges, specifically with the goal to limit the ball back-spinning ability of today’s modern golf clubs. Thus, some golf club head designs that result in high backspin are deemed to be nonconforming–for example, golf club irons and wedges with: grooves dimensioned larger than the USGA rules; grooves having a radius between the striking face and groove side wall smaller and sharper than specified by the USGA rules; striking faces made of a nonmetallic material such as rubber; striking face surface roughness exceeding the USGA rules. In the interest of complying with the USGA rules and marketability, most manufacturers are designing and selling only golf club irons and wedges that are fully conforming. Therefore, in today’s golf club marketplace, generally the only clubs available to a golfer, even if the golfer desires to use nonconforming clubs, are those that comply with the spin-reduced, post-2008 USGA rules.

[0012] While golf irons and wedges are not designed for as much precision as a putter, golf irons and wedges are nevertheless scoring clubs, as opposed to drivers and woods, which are distance clubs. That is, with irons (and especially wedges), a golfer intends to land the ball as close to the target (or pin) as possible, while with woods, the golfer intends to gain as much distance as possible. When using irons and wedges, the golfer assumes that the closer the golfer is to the pin, the closer the golfer’s shot should land to the pin. For example, if a golfer is 170 yards away, the golfer may use a 5-iron (e.g., 29 degrees) to traverse that 170 yard distance. The golfer’s expectation may be that the golfer expects the ball to land anywhere on a 15 yard radius green, and not in any adjacent hazard. However, if the same golfer is only 100 yards away, the golfer may use a pitching wedge (e.g., 48 degrees) to traverse that distance, but the golfer’s expectation will be that the ball should land within 25 feet of the pin, and not just anywhere on the green.

[0013] In the short game, a golfer typically uses high lofted wedges, and because the distance to the target is shorter, the expectation of the result is proportionally greater. For example, if the same golfer is only 40 yards away from the pin, the golfer may use a sand wedge (e.g., 54 degrees) and expect to land the golfer’s ball within 15 feet of the pin. However, if the same golfer is only 15 yards away from the pin, the golfer may use a lob wedge (e.g., 60 degrees) and expect to land the golfer’s ball within 5 feet of the pin.

[0014] Given the proportionally greater expectation for precision with higher lofted wedges, the ball back-spinning ability of the wedges is very important. The ball back-spinning ability of the wedges is even more important when used to escape a bunker or rescue a ball from the heavy rough. For example, when striking a ball from the heavy rough, grass and water will typically be trapped between the ball and striking face upon impact. The grass and water will dramatically reduce the resulting ball backspin, because they interfere with the clean, friction-producing striking face of the golf club. However, large grooves on a golf club may allow the grass and water to be channeled away, thereby resulting in greater ball spin than with smaller grooves. However, even with large grooves, it is often the case that a ball hit from the rough will have less backspin than the same ball hit from the fairway, because inevitably some grass and water will interfere with the striking face of the club.

[0015] As it is evident to the golfer of ordinary skill in the art, golf is as much a mental challenge as it is a physical challenge. The mental aspect can be highlighted in the frequent occasions where a golfer misses a critical five foot putt (perhaps for a championship win)–where five foot putts in noncompetition situations are consistently made, even by young children. Especially with respect to golf irons and especially wedges, it is imperative for the golfer to have the utmost confidence in the golfer’s clubs. For example, for distance control, a golfer may demand that the golfer’s 7 iron (e.g. 36 degrees) travels precisely 150 yards, and the golfer’s 8 iron (e.g., 40 degrees) exactly 10 yards less at 140 yards. For wedges that are specialized for the short game, distance control is even more important. For example, the golfer may demand that for a 15 yard chip shot, the golfer’s sand wedge (e.g., 54 degrees) travels 7.5 yards in the air, and rolls 7.5 yards after landing, while if the golfer used the golfer’s lob wedge (e.g., 60 degrees), the golfer may expect the ball to travel 10 yards in the air, and roll 5 yards. Thus, the consistent performance of a golfer’s golf clubs inspire confidence, which usually leads to better accuracy and scores.

[0016] In addition to confidence from consistently performing golf clubs, the golfer gains confidence from golf clubs that generally inspire confidence due to their design. For example, a large, 460 cc driver may instill confidence in a golfer because the large club head looks like the golfer can swing for the fences and never worry about mis-hitting or missing the ball. Similarly, for golf irons and especially wedges, large grooves inspire confidence because the golfer is convinced that the club will generate massive amounts of ball backspin, allowing the golfer to precisely hit the golfer’s target and not roll-out. Moreover, design features that emphasize the large grooves, such as contrasting colors, will further instill confidence by making the large grooves appear even bigger than they are physically.

[0017] As discussed above, the USGA rules limit the size of the grooves, and therefore, the groove geometries are generally the same (i.e., at the maximum dimensions) between manufacturers. The USGA and R&A rules concerning surface roughness and groove geometry should not be considered as limitations to any embodiments discussed in this application, except where expressly acknowledged as a limitation. However, considering the mental aspect of the golf game, Applicants have determined that there is a distinct, confidence-building advantage in creating the appearance that the grooves are larger than they physically are, without breaking the USGA rules, resulting in a conforming golf club.

[0018] In one embodiment of the invention, the grooves of a golf club iron head are surrounded by groove enh
ancement areas that have a surface finish identical to that of the grooves, but different from the remainder of the striking face. This results in the appearance that the grooves are as large as the grooves plus the surrounding groove enhancement areas, without breaking the USGA design rules. For instance, the confidence derived from the perception that the grooves are larger than they are physically, could cause a golfer to hit the ball with more purposeful intent. That is, to confidently hit the ball with an accelerating blow, which will produce a good amount of ball backspin–as opposed to glancing the ball with a decelerating swing, which leads to a lack of ball backspin, which may be the case if the golfer lacks confidence in his golf club.

[0019] In another embodiment, the grooves themselves have a surface finish identical to that of the striking face, and the groove enhancement areas surrounding the grooves have a second surface finish that emphasizes the grooves. In another embodiment, only the bottom of the grooves themselves have a surface finish identical to that of the striking face, and the side walls of the grooves and the groove enhancement areas surrounding grooves have a second surface finish that emphasizes the grooves.