US20150018114A1

US20150018114A1 - Golf clubs and shafts configured for consistent club gapping

Info

Publication number: US20150018114A1
Application number: US14/329,551
Authority: US
Inventors: Ryan M. Stokke; Martin R. Jertson; Bradley D. Schweigert
Original assignee: Karsten Manufacturing Corp
Current assignee: Karsten Manufacturing Corp
Priority date: 2013-07-12
Filing date: 2014-07-11
Publication date: 2015-01-15
Also published as: JP2016523683A; GB2531672A; WO2015006589A1; KR20160030291A; GB201601275D0

Abstract

Some embodiments include a set of golf club shafts configured for consistent club gapping. Other embodiments for related golf club shafts and golf clubs, and related methods are also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 61/845,765, filed Jul. 12, 2013. U.S. Provisional Application No. 61/845,765 is incorporated herein by reference in its entirety.

TECHNICAL FIELD

This disclosure relates generally to sports equipment, and relates more particularly to golf club shafts and golf clubs, and related methods.

BACKGROUND

Many people experience difficulty in achieving a consistent distance gap between golf shots hit with adjacent iron-type or hybrid-type golf clubs (e.g., a 5-iron-type golf club versus a 6-iron-type golf club). This difficulty can be particularly noticeable when using longer iron-type or hybrid-type golf clubs having smaller loft angles.

BRIEF DESCRIPTION OF THE DRAWINGS

To facilitate further description of the embodiments, the following drawings are provided in which:

FIG. 1 illustrates a schematic view of an exemplary golf club shaft, according to an embodiment;

FIG. 2 illustrates a tip end side cross-sectional view of the golf club shaft of FIG. 1, according to the embodiments of FIG. 1;

FIG. 3 illustrates a butt end side cross-sectional view of the golf club shaft of FIG. 1, according to the embodiment of FIG. 1;

FIG. 4 illustrates a butt end side cross-sectional view of another golf club shaft, according to another embodiment;

FIG. 5 illustrates a schematic view of a golf club, according to another embodiment;

FIG. 6 illustrates a side view of a set of golf clubs, according to another embodiment; and

FIG. 7 illustrates a flow chart for an exemplary procedure of providing a set of golf clubs.

For simplicity and clarity of illustration, the drawing figures illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the present disclosure. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present disclosure. The same reference numerals in different figures denote the same elements.
The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.
The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the apparatus, methods, and/or articles of manufacture described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.
The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements mechanically and/or otherwise. Two or more mechanical elements may be mechanically coupled together, but not be electrically or otherwise coupled together. Coupling may be for any length of time, e.g., permanent or semi-permanent or only for an instant. “Mechanical coupling” and the like should be broadly understood and include mechanical coupling of all types.
The absence of the word “removably,” “removable,” and the like near the word “coupled,” and the like does not mean that the coupling, etc. in question is or is not removable.
As defined herein, two or more elements are “integral” if they are comprised of the same piece of material. As defined herein, two or more elements are “non-integral” if each is comprised of a different piece of material.
As defined herein, “approximately” can, in some embodiments, mean within plus or minus ten percent of the stated value. In other embodiments, “approximately” can mean within plus or minus five percent of the stated value. In further embodiments, “approximately” can mean within plus or minus three percent of the stated value. In yet other embodiments, “approximately” can mean within plus or minus one percent of the stated value. The apparatus, methods, and articles of manufacture described herein are not limited in this regard.

DETAILED DESCRIPTION OF EXAMPLES OF EMBODIMENTS

Various embodiments include a set of shafts for golf clubs. The set of shafts can include two or more shafts each configured for an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. Each shaft of the set of shafts can include an elongate body, a tip end, a butt end, a midpoint, and a center of gravity. The elongate body can extends between the tip end and the butt end. The center of gravity can be located a first distance from the midpoint. The first distance can be greater than or equal to approximately 6.0% of a second distance from the midpoint to the butt end. The center of gravity can be located closer to the butt end than to the tip end.
Many embodiments include a set of golf clubs. The set of golf clubs can include two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. Each golf club of the set of golf clubs can include a shaft. The shaft can include an elongate body, a tip end, a butt end, a midpoint between the tip end and the butt end, and a center of gravity. The elongate body can extend between the tip end and the butt end. The center of gravity can be located a first distance from the midpoint. The first distance can be greater than or equal to approximately 6.0% of a second distance from the midpoint to the butt end. The center of gravity can be located closer to the butt end than to the tip end.
Some embodiments can include a method. The method can include providing a set of golf clubs. The set of golf clubs can include two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. Each golf club of the set of golf clubs can include a shaft. The shaft can include an elongate body, a tip end, a butt end, a midpoint, and a center of gravity. The elongate body can extend between the tip end and the butt end. The center of gravity can be located a first distance from the midpoint. The first distance can be greater than or equal to approximately 6.0% of a second distance from the midpoint to the butt end. The center of gravity can be located closer to the butt end than to the tip end.
Turning to the drawings, FIG. 1 illustrates a schematic view of a shaft 100, according to an embodiment. Shaft 100 is merely exemplary and embodiments of the shaft are not limited to the embodiments presented herein. The shaft can be employed in many different embodiments or examples not specifically depicted or described herein.
Shaft 100 can be an elongate body, and can have a tip end 101 and a butt end 102. The elongate body can extend between the tip end and the butt end. Shaft 100 can have a shaft length 107. In various embodiments, shaft 100 can have a midpoint 103 such that a half-length distance 108 from midpoint 103 to butt end 102 is one-half of shaft length 107. Midpoint 103 can bisect shaft 100 into a tip side 104 and a butt side 105.
In certain embodiments, shaft 100 can have a center of gravity 106 located closer to butt end 102 than to tip end 101. Center of gravity 106 can be located along butt side 105 between midpoint 103 and butt end 102. Specifically, center of gravity 106 can be located a distance 109 from midpoint 103 such that shaft 100 has a high center of gravity. In many embodiments, distance 109 can be greater than or equal to approximately 6.0% of half-length distance 108. In further embodiments, distance 109 can be greater than or equal to approximately 9.0% of half-length distance 108. In still further embodiments, distance 109 can be greater than or equal to approximately 11.0% of half-length distance 108. For example, distance 109 can be greater than or equal to approximately 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, or 15.0% of half-length distance 108. As distance 109 increases as a percentage of half-length distance 108, center of gravity 106 is positioned so as to be closer to butt end 102.
Turning ahead in the drawings, FIG. 2 illustrates a tip end side cross-sectional view of shaft 100. FIG. 3 illustrates a butt end side cross-sectional view of shaft 100. Shaft 100 can include a tubular wall surrounding a hollow core. At the tip end of shaft 100, as shown in FIG. 2, a wall 201 can surround a hollow core 202, and shaft 100 can have a tip outer diameter 203 and a tip inner diameter 204. Wall 201 can have a thickness 205 at the tip end. At the butt end of shaft 100, as shown in FIG. 3, a wall 301 can surround a hollow core 302, and shaft 100 can have a butt outer diameter 303 and a butt inner diameter 304. Wall 301 can have a thickness 305 at the butt end. The wall (e.g., 201, 301) of shaft 100 can be made of steel. The thickness of the wall can increase from the tip end to the butt end, such that thickness 305 of wall 301 at butt end 102 (FIG. 1) is greater than thickness 205 at tip end 201. In a number of embodiments, the thickness of the wall can gradually increase at uniform rate when moving from tip end 101 (FIG. 1) to butt end 102 (FIG. 1). In other embodiments, the thickness of the wall can increase at a non-uniform rate when moving from tip end 101 (FIG. 1) to butt end 102 (FIG. 1). In certain embodiments, at each cross section of shaft 100, the wall can have an approximately uniform thickness. In a number of embodiments, tip outer diameter 203 can be between approximately 0.325 and 0.380 inches. Butt outer diameter 303 can be between approximately 0.560 and 0.630 inches. In further embodiments, shaft 100 can have a wall thickness varying between 0.008 to 0.030 inches, such as, for example, when shaft 100 comprises steel. In certain embodiments, thickness 205 at tip end 101 (FIG. 1) can be between approximately 0.008 and 0.018 inches, and thickness 305 at butt end 102 (FIG. 1) can be between approximately 0.015 and 0.030 inches. For example, thickness 205 at tip end 101 (FIG. 1) can be 0.010 inches and thickness 305 at butt end 102 (FIG. 1) can be 0.025 inches. In some embodiments, the wall thickness of shaft 100 can become thinner moving toward tip end 101 (FIG. 1) from butt end 102 (FIG. 1), but can become thicker within a few inches of tip 102 for added structural support for attachment to the hosel of a club head. By having a greater wall thickness at butt side 105 (FIG. 1) than tip side 104 (FIG. 1), the center of gravity of steel shaft 100 can be positioned closer toward butt end 102 (FIG. 1).
Alternatively, or in addition, the shaft can be made of graphite (e.g., carbon fiber), fiberglass, and/or other suitable materials. In certain embodiments, the shaft can be made of a lower density material, such as carbon fiber or fiberglass, and impregnated with a higher density weighting material, such as steel or tungsten. The density of carbon fiber can be between approximately 1.0 and 2.0 grams per cubic centimeter. The density of fiberglass can be between approximately 1.5 and 3.0 grams per cubic centimeter. The density of steel can be between approximately 7.5 and 8.2 grams per cubic centimeter. The density of tungsten can be between approximately 14 and 19 grams per cubic centimeter.
For example, FIG. 4 illustrates a butt end side cross-sectional view of shaft 400, according to an embodiment. Shaft 400 can be similar to shaft 100 (FIGS. 1-3), and various components and/or constructions of shaft 400 can be identical to various components of shaft 100. Shaft 400 can include a tubular wall surrounding a hollow core. At the butt end of shaft 400, as shown in FIG. 4, a wall 401 can surround a hollow core 402, and shaft 400 can have a butt outer diameter 403 and a butt inner diameter 404. Wall 401 can have a thickness 405 at the butt end. The tip end of shaft 400 can be similar to the tip end of shaft 100, as shown in FIG. 2, the thickness of wall 401 can be approximately uniform from the butt end to the tip end, such that thickness 405 is the same as the thickness at the tip end of shaft 400. Shaft 400, and other embodiments of graphite shafts, can have a wall thickness between approximately 0.010 and 0.100 inches. Wall 401 of shaft 400 can be made of carbon fiber and can be impregnated with a weighting material, such as tungsten, between the midpoint and the butt end, on the butt side of shaft 400. The weighting material, such as tungsten, can have a higher density than the carbon fiber. In some embodiments, the weighting material can be impregnated in shaft 400, such that the density of shaft 400 gradually increases from the tip end to the butt end, or at least from the midpoint to the butt end. By using impregnated weighting material on the butt side of shaft 400, the center of gravity of shaft 400 can be positioned closer toward the butt end. In many embodiments, the center of gravity of the shaft can be positioned closer to the butt end by varying the densities of the shaft and/or varying the wall thickness of the shaft without adding weights to the outside of the butt side of the shaft or to the hollow core of the butt side of the shaft.
FIG. 5 illustrates a schematic view of a golf club 500, according to an embodiment. Golf club 500 is merely exemplary and embodiments of the golf club are not limited to the embodiments presented herein. The golf club can be employed in many different embodiments or examples not specifically depicted or described herein.
Golf club 500 can include a club head 501, a shaft 503, and a grip 506. Shaft 503 can be similar or identical to shaft 100 (FIGS. 1-3) and/or shaft 400 (FIG. 4), and various components and/or constructions of shaft 503 can be identical to various components of shaft 100 and/or shaft 400. Golf club 500 has a swing weight, which generally is a predetermined feel of the club when it is swung. The swing weight of golf club 500 can be measured by determining the net moment of golf club 500 about a pivot point 512 on fulcrum 505. Pivot point 512 can be a distance 508 from the butt of the club. Distance 508 is defined as 14.0 inches for the lorythmic swing weight scale. Club head 501 can have a center of gravity 502 located a distance 509 from pivot point 512. Shaft 503 can have a center of gravity 504 located a distance 510 from pivot point 512. Grip 506 can have a center of gravity 507 located a distance 511 from pivot point 512. The weight of each component of the golf club (i.e., club head 501, shaft 503, and grip 506) can affect the swing weight of golf club 500. Further, the distance of the center of gravity from the pivot point for each component (i.e., distance 509 for center of gravity 502 of club head 501, distance 510 for center of gravity 504 of shaft 503, and distance 511 for center of gravity 507 of grip 506) can affect the swing weight of golf club 500. In other words, the swing weight can be altered by changing the weight of club head 501, shaft 504, and/or grip 506, or by moving the center of gravity of club head 501, shaft 504, and/or grip 506. For example, increasing the length of golf club 500 and moving center of gravity 502 such that distance 509 increases can change the swing weight. The length of shaft 503 and/or the length of assembled golf club 500 can thus affect swing weight. The swing weight measurement, which can be measured in inch-ounces (in-oz) can be converted to an alphanumeric combination, as shown in Table 1.

TABLE 1

Swing Weight Conversions.

	Moment (in-oz)	Swing Weight

	160.00	A0
	161.75	A1
	163.50	A2
	165.25	A3
	167.00	A4
	168.75	A5
	170.50	A6
	172.25	A7
	174.00	A8
	175.75	A9
	177.50	B0
	179.25	B1
	181.00	B2
	182.75	B3
	184.50	B4
	186.25	B5
	188.00	B6
	189.75	B7
	191.50	B8
	193.25	B9
	195.00	C0
	196.75	C1
	197.50	C2
	200.25	C3
	202.00	C4
	203.75	C5
	205.50	C6
	207.25	C7
	209.00	C8
	210.75	C9
	212.50	D0
	214.25	D1
	216.00	D2
	217.75	D3
	219.50	D4
	221.25	D5
	223.00	D6
	224.75	D7
	226.50	D8
	228.25	D9
	230.00	E0
	231.75	E1
	233.50	E2
	235.25	E3
	237.00	E4
	238.75	E5
	240.50	E6
	242.25	E7
	244.00	E8
	245.75	E8
	247.50	F0

Turning ahead in the drawings, FIG. 6 illustrates a set of golf clubs 600. Set of golf clubs 600 is merely exemplary and embodiments of the set of golf clubs are not limited to the embodiments presented herein. The set of golf clubs can be employed in many different embodiments or examples not specifically depicted or described herein.
Set of golf clubs 600 can include three golf clubs, 610, 620, and 630, each being a different one of an iron-type golf club. Each golf club (e.g., 610, 620, or 630) of set of golf clubs 600 can be similar or identical to golf club 500 (FIG. 5), and various components and/or constructions of each golf club (e.g., 610, 620, 630) can be identical to various components of golf club 500. Each golf club of set of golf clubs 600 can include a shaft, a club head, and a grip. For example, golf club 610 can include a shaft 611, a club head 612 having a face 613, and a grip 614. Golf club 620 can include a shaft 621, a club head 622 having a face 623, and a grip 624. Golf club 630 can include a shaft 631, a club head 632 having a face 633, and a grip 634. Shafts 611, 621, and/or 631 can be similar or identical to shaft 100 (FIGS. 1-3) and/or shaft 400 (FIG. 4), and various components and/or constructions of shafts 611, 621, and/or 631 can be similar or identical to various components of shaft 100 and/or shaft 400. Each golf club (e.g., 610, 620, 630) can have a discrete club number associated with a loft angle of the face (e.g., 613, 623, 633) of the club head (e.g., 612, 622, 632). The club number can be used to identify a certain golf club of the set with predetermined degrees of loft. Club numbers for iron-type golf clubs can include 1 through 9, as well as wedges, such as a pitching wedge (PW), a utility wedge (UW), a sand wedge (SW), and a lob wedge (LW). Although the exact loft angle can vary slightly in various embodiments, the loft angle of the face can be converted to a club number, as shown in Table 2.

TABLE 2

Iron-Type Club Number and Loft Angle.

	Club #	Loft Angle (degrees)

	1	14
	2	17
	3	20
	4	23
	5	26
	6	29
	7	32
	8	36
	9	40
	PW	45
	UW	50
	SW	54
	LW	58

For example, face 613 of golf club 610 can have a loft angle of 20 degrees and can be a 3-iron; face 623 of golf club 620 can have a loft angle of 26 degrees and can be a 5-iron; and face 633 of golf club 630 can have a loft angle of 32 degrees and can be a 7-iron. Shafts configured for a golf club having a certain club number can have a corresponding shaft number. In addition to changes in loft angle, in many embodiments, iron-type golf clubs with a lower loft angle can have a greater length than iron-type golf clubs with a higher loft angle. Accordingly, lower number clubs are often called long irons, and higher number clubs are often called short irons. In some embodiments, the set of golf clubs can include hybrid-type golf clubs. Although the club numbers of hybrid-type golf clubs are often designated by the loft angle, each hybrid-type golf club can have an equivalent iron-type club number, as shown in Table 3. For purposes of this description, hybrid-type golf clubs are designated by their equivalent iron-type club number. For example, a 2-hybrid-type golf club signifies a hybrid-type club head with a loft angle of 17 degrees.

TABLE 3

Hybrid-Type Club Number and Loft Angle.

Club #	Loft Angle (degrees)	Equivalent Iron-Type Number

17	17	2
20	20	3
23	23	4
26	26	5
29	29	6

Different club numbers can be used for hitting a golf ball different distances. The lower club numbers can be used for longer shots, and the higher club numbers for shorter shots. By using effectively the same swing with different clubs, the various iron-type golf clubs can be used to achieve different distances. Many people, however, have difficulty achieving consistent variations in distances when using adjacent iron-type golf clubs. For example, many players would like a 10-15 yard increase in the distance for shots with each descending club number. For some players, this gap is often hardest to achieve with long iron-type golf clubs, such as the 3-iron- to 7-iron-type golf clubs. For example, the distance between shots using a 3-iron- and a 4-iron-type golf club might not be as well defined or consistent as the distance between shots using short iron-type golf clubs, such as an 8-iron- and an 9-iron-type golf club. Difficulties in achieving consistent club gapping can make determining which club to use at long distances difficult.
In some embodiments, a set of golf clubs can be optimized for consistent club gapping by creating a greater difference in lengths between the golf clubs of different club numbers and/or by creating a greater difference in weight of the club head in golf clubs of different club numbers. By adding weight to the club head, the momentum of the club head can be increased, which can increase the energy transferred to the ball upon contact. Similarly, by increasing the length of the golf club, the speed of the club head can be increased, which can increase the energy transferred to the ball upon contact. Increasing the weight of the club head and/or increasing the length of the golf club, however, can affect the swing weight, and many players prefer a consistent swing weight across the set of iron-type golf clubs to maintain the same feel of the swing across the clubs. In various embodiments, by shifting weight toward the butt end of the golf club, the increased weight of the club head and/or the increased length of the golf club can be offset to maintain a consistent swing weight. In certain embodiments, the weight of certain club heads in a set of golf clubs can be increased, and the length of the golf clubs in the set of golf clubs can be kept the same. In other embodiments, the length of certain golf clubs in the set of golf clubs can be increased and the weight of the club heads in the set of golf clubs can be kept the same. In yet further embodiments, the weight of certain club heads can be increased, and the lengths of certain club heads can be increased. In a number of embodiments, swing weight can be maintained by moving the center of gravity of the shaft toward the butt end.
For example, Table 4 provides data for an exemplary set of steel shafts, according to an embodiment, in which two or more shafts have a high center of gravity (i.e., in which the center of gravity has been moved toward the butt end). The lengths described can be within approximately plus or minus 0.125 inches. The weights described can be within approximately plus or minus 3.6 grams. The center of gravity is positioned on the butt side of the shaft, and the distance from the center of gravity to the midpoint is identified, as well as that distance as a percentage of the shaft half-length.

TABLE 4

Exemplary Steel Shafts with High Center of Gravity.

	Length	Weight	Distance from CG to	Percentage of
Shaft #	(inches)	(grams)	Midpoint (inches)	Half-length

3	41.000	125.8	2.6000	12.68%
4	40.250	124.1	2.5250	12.55%
5	39.500	122.4	2.4500	12.41%
6	38.750	120.6	2.3750	12.26%
7	38.125	119.1	2.3625	12.39%
8	37.500	117.7	2.2500	12.00%
9	36.875	116.2	2.2375	12.14%
SW	36.500	115.3	2.2500	12.33%

Table 5 provides data for an exemplary set of graphite shafts, according to an embodiment, in which two or more shafts have a high center of gravity. The lengths described can be within approximately plus or minus 0.125 inches. The weights described can be within approximately plus or minus 3.6 grams. The center of gravity is positioned on the butt side of the shaft, and the distance from the center of gravity to the midpoint is identified, as well as that distance as a percentage of the shaft half-length.

TABLE 5

Exemplary Graphite Shafts with High Center of Gravity.

4	39.500	75	2.9	14.43%
5	38.750	73	2.3	11.74%
6	38.000	72	1.6	8.42%
7	37.375	71	1.2	6.35%
8	36.750	70	0.8	4.22%
9	36.125	69	0.0	−0.21%
SW	35.500	65	−0.4	−1.97%

In some embodiments, a set of shafts can include two or more shafts each configured for an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. For example, the two or more shafts can include a first shaft configured for a 4-iron-type golf club, a second shaft configured for a pitching-wedge-type golf club, and a third shaft configured for a 3-hybrid-type golf club. In certain embodiments, the two or more shafts can each be configured for a different golf club ranging from a 1-iron-type golf club to a 9-iron-type golf club. For example, the two or more shafts can include a first shaft configured for a 3-iron-type golf club, a second shaft configured for a 4-iron-type golf club, and a third shaft configured for a 5-iron-type golf club. In certain other embodiments, the two or more shafts can be configured for one or more iron-type golf clubs and one or more wedge-type golf clubs. For example, the two or more shafts can include a first shaft configured for a 5-iron-type golf club and a second shaft configured for a sand-wedge-type golf club. In yet further embodiments, the two or more shafts can each be configured for a different golf club ranging from a 2-bybrid- to a 5-hybrid-type golf club. For example, the two or more shafts can include a first shaft configured for a 2-hybrid-type golf club, a second shaft configured for a 3-hybrid-type golf club, and a third shaft configured for a 4-hybrid-type golf club.
Each shaft (e.g., shaft 611 (FIG. 6), shaft 621 (FIG. 6), or shaft 631 (FIG. 6)) can be identical or substantially similar to shaft 100 (FIGS. 1-3) and/or shaft 400 (FIG. 4), and various components and/or constructions of the shafts can be identical to various components of shaft 100 and/or shaft 400. Specifically, each shaft can be an elongate body with a tip end, a butt end, a midpoint, and a center of gravity, in which the elongate body extends between the tip end and the butt end. The center of gravity can be located closer to the butt end than to the tip end, and the center of gravity can be a distance from the midpoint that is greater than or equal to approximately 6.0% of a half-length of the shaft. As described above, in other embodiments, the distance from the center of gravity to the midpoint can be greater than or equal to approximately 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, or 15.0% of the half-length of the shaft. In some embodiments, the set of shafts can include three or more shafts each having a different loft angle. In other embodiments, the set of shafts can include four or more shafts each having a different loft angle. In further embodiments, the set of shafts can include five or more shafts each having a different loft angle.
For example, for the steel shafts described in Table 4, the set of shafts can include two, three, four, five, six, seven, or even eight shafts each having a high center of gravity. Specifically, the distance from the center of gravity to the midpoint in each shaft of the set of shafts is greater than or equal to approximately 12.0% of the half length of the shaft. In some embodiments, the two or more shafts can be configured for any iron-type golf club number, including wedges (e.g., PW, UW, SW, LW). In other embodiments, the two or more shafts can each be configured only for the 1-iron- to 9-iron-type golf clubs. Specifically, the two or more shafts can, in certain embodiments, be configured only for iron-type golf clubs having a loft angle equal to or less than approximately 40 degrees. In various embodiments, the two or more shafts can each be configured for a different one of an iron-type golf club within the 1-iron- to 9-iron-type golf clubs, such as a 1-iron- to 7-iron-type golf club, a 1-iron- to 5-iron-type golf club, a 1-iron- to 3-iron-type golf club, a 2-iron- to 7-iron-type golf club, a 2-iron- to 5-iron-type golf club, a 2-iron- to 3-iron-type golf club, a 3-iron- to 9-iron-type golf club, a 3-iron- to 6-iron-type golf club, a 3-iron- to 4-iron-type golf club, a 4-iron- to 8-iron-type golf club, a 4-iron- to 6-iron-type golf club, a 5-iron- to 7-iron-type golf club, or another suitable range of an iron-type golf club.
In some embodiments, one or more of the shafts configured for the iron-type golf clubs can be provided at a full untrimmed length, and can have a high center of gravity characteristic, as described above. In other embodiments, one or more of the shafts can be provided at a trimmed length for a golf club, and can have a high center of gravity characteristic, as described above. In some embodiments, each shaft can be incorporated in a golf club at the trimmed length and have a high center of gravity characteristic as described above. When assembled in the set of golf clubs, the shafts can have a standard length, or can be longer or shorter, such as for taller or shorter people. Table 6 provides data for exemplary steel shafts assembled in golf clubs that have been trimmed to a standard length. Table 7 provides data for exemplary steel shafts assembled in golf clubs that have been trimmed to a length of one inch longer than the standard length. Table 8 provides data for exemplary steel shafts assembled in golf clubs that have been trimmed to a length of two inches longer than the standard length. Table 9 provides data for exemplary steel shafts assembled in golf clubs that have been trimmed to a length of one inch shorter than the standard length. Table 10 provides data for exemplary steel shafts assembled in golf clubs that have been trimmed to a length of two inches shorter than the standard length. In each case a set of shafts can have a high center of gravity characteristic, as described above.

TABLE 6

Exemplary High Center of Gravity Steel Shafts Trimmed
for Standard Length Clubs.

3	37.58	116.2	2.21	11.75%
4	37.08	115.2	2.14	11.57%
5	36.58	114.2	2.08	11.38%
6	36.08	113.1	2.02	11.19%
7	35.58	112.0	2.01	11.32%
8	35.08	110.9	1.91	10.87%
9	34.58	109.8	1.90	10.99%
PW	34.33	109.2	1.92	11.18%
UW	34.33	109.2	1.92	11.18%
SW	34.08	108.5	1.91	11.19%
LW	33.83	89.4	1.89	11.20%

TABLE 7

Exemplary High Center of Gravity Steel Shafts Trimmed for Clubs One
Inch Longer Than Standard Length.

3	38.58	119.0	2.26	11.70%
4	38.08	118.0	2.19	11.53%
5	37.58	117.0	2.13	11.35%
6	37.08	115.9	2.07	11.16%
7	36.58	114.8	2.06	11.28%
8	36.08	113.7	1.96	10.85%
9	35.58	112.6	1.95	10.97%
PW	35.33	112.0	1.97	11.15%
UW	35.33	112.0	1.97	11.15%
SW	35.08	111.3	1.96	11.16%
LW	34.83	92.2	1.94	11.17%

TABLE 8

Exemplary High Center of Gravity Steel Shafts Trimmed for Clubs
Two Inches Longer Than Standard Length.

3	39.58	121.8	2.31	11.66%
4	39.08	120.8	2.24	11.49%
5	38.58	119.8	2.18	11.31%
6	38.08	118.7	2.12	11.13%
7	37.58	117.6	2.11	11.25%
8	37.08	116.5	2.01	10.83%
9	36.58	115.4	2.00	10.94%
PW	36.33	114.8	2.02	11.12%
UW	36.33	114.8	2.02	11.12%
SW	36.08	114.1	2.01	11.13%
LW	35.83	95.0	1.99	11.13%

TABLE 9

Exemplary High Center of Gravity Steel Shafts Trimmed for
Clubs One Inch Shorter Than Standard Length.

3	36.58	113.4	2.16	11.79%
4	36.08	112.4	2.09	11.61%
5	35.58	111.4	2.03	11.42%
6	35.08	110.3	1.97	11.23%
7	34.58	109.2	1.96	11.35%
8	34.08	108.1	1.86	10.90%
9	33.58	107.0	1.85	11.02%
PW	33.33	106.4	1.87	11.22%
UW	33.33	106.4	1.87	11.22%
SW	33.08	105.7	1.86	11.23%
LW	32.83	86.6	1.84	11.24%

TABLE 10

Exemplary High Center of Gravity Steel Shafts Trimmed for
Clubs Two Inches Shorter Than Standard Length.

3	35.58	110.6	2.11	11.84%
4	35.08	109.6	2.04	11.66%
5	34.58	108.6	1.98	11.46%
6	34.08	107.5	1.92	11.26%
7	33.58	106.4	1.91	11.40%
8	33.08	105.3	1.81	10.93%
9	32.58	104.2	1.80	11.05%
PW	32.33	103.6	1.82	11.26%
UW	32.33	103.6	1.82	11.26%
SW	32.08	102.9	1.81	11.27%
LW	31.83	83.8	1.79	11.28%

In some embodiments, a set of golf clubs can include two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. For example, the two or more golf clubs can include a 4-iron-type golf club, a pitching-wedge-type golf club, and a 3-hybrid-type golf club. In certain embodiments, the two or more golf clubs can each be a different golf club ranging from a 1-iron-type golf club to a 9-iron-type golf club. For example, the two or more golf clubs can include a 3-iron-type golf club, a 4-iron-type golf club, and a 5-iron-type golf club. In certain other embodiments, the two or more golf clubs can be one or more iron-type golf clubs and one or more wedge-type golf clubs. For example, the two or more golf clubs can include a 5-iron-type golf club and a sand-wedge-type golf club. In yet further embodiments, the two or more golf clubs can each be a different golf club ranging from a 2-hybrid- to a 5-hybrid-type golf club. For example, the two or more golf clubs can include a 2-hybrid-type golf club, a 3-hybrid-type golf club, and a 4-hybrid-type golf club.
The set of golf clubs can be identical or substantially similar to set of golf clubs 600 (FIG. 6), and various components and/or constructions of the set of golf clubs can be identical to various components of set of golf clubs 600. Each golf club can be identical or substantially similar to golf club 500 (FIG. 5), and various components and/or constructions of the golf clubs can be identical to various components of golf club 500. Specifically, each golf club of the set of golf club can include a shaft. The shaft can be identical or substantially similar to shaft 100 (FIGS. 1-3) and/or shaft 400 (FIG. 4), and various components and/or constructions of the shaft can be identical to various components of shaft 100 and/or shaft 400. As described above, the shaft can be an elongate body with a tip end, a butt end, a midpoint, and a center of gravity, and in which the elongate body extends between the tip end and the butt end. The center of gravity can be located closer to the butt end than to the tip end, and the center of gravity can be a distance from the midpoint that is greater than or equal to approximately 6.0% of a half-length of the shaft. As described above, in other embodiments, the distance from the center of gravity to the midpoint can be greater than or equal to approximately 6.0%, 6.5%, 7.0%, 7.5%, 8.0%, 8.5%, 9.0%, 9.5%, 10.0%, 10.5%, 11.5%, 12.0%, 12.5%, 13.0%, 13.5%, 14.0%, 14.5%, or 15.0% of the half-length of the shaft. In some embodiments, the set of golf clubs can include three or more golf clubs each having a different loft angle. In other embodiments, the set of golf clubs can include four or more golf clubs each having a different loft angle. In further embodiments, the set of golf clubs can include five or more golf clubs each having a different loft angle.
The set of golf clubs can include two or more golf clubs each having a shaft with a high center of gravity, as described above. In some embodiments, the two or more golf clubs can be any iron-type club number, including wedges (e.g., PW, UW, SW, LW). In other embodiments, the two or more golf clubs can each be 1-iron- to 9-iron-type golf clubs, and limited to clubs having a loft angle less than or equal to approximately 40 degrees. In various embodiments, the two or more golf clubs can each be a different one of an iron-type golf club within the 1-iron- to 9-iron-type golf clubs, such as a 1-iron- to 7-iron-type golf club, a 1-iron- to 5-iron-type golf club, a 1-iron- to 3-iron-type golf club, a 2-iron- to 7-iron-type golf club, a 2-iron- to 5-iron-type golf club, a 2-iron- to 3-iron-type golf club, a 3-iron- to 9-iron-type golf club, a 3-iron- to 6-iron-type golf club, a 3-iron- to 4-iron-type golf club, a 4-iron- to 8-iron-type golf club, a 4-iron- to 6-iron-type golf club, a 5-iron- to 7-iron-type golf club, or another suitable range of an iron-type golf club.
In some embodiments, the weight of the club head and/or length of the golf club for each of the two or more golf clubs within the set of golf clubs is increased to optimize club gapping. In some such embodiments, the swing weight of each golf club within the set of golf clubs can be the same or substantially similar. In some embodiments, the swing weight measurement for each golf club within the set of golf clubs can be within plus or minus approximately 1.0 in-oz. For example, a first golf club in the set of golf clubs can have a swing weight of 212.50 in-oz (corresponding to a alphanumeric swing weight of D0), a second golf club in the set of golf clubs can have a swing weight of 211.90 in-oz, and a third golf club in the set of golf clubs can have a swing weight of 213.10 in-oz. In certain embodiments, the swing weight of each golf club is between approximately 205.00 and 216.50 in-oz. Table 11 provides data for exemplary iron-type golf clubs optimized for consistent club gapping (in this embodiment, having both an increase in head weight), and also having high center of gravity steel shafts for maintaining swing weight. Table 12 provides data for exemplary iron-type golf clubs optimized for consistent club gapping (in this embodiment, having both an increase in head weight), and also having high center of gravity graphite shafts for maintaining swing weight. The club weights listed can be minimum club head weights for optimizing consistent club gapping. For example, a first golf club of a set of three or more golf clubs can be a 3-iron-type golf club with a club head weight of at least 247 grams. A second golf club of the set of three or more golf clubs can be a 4-iron-type golf club with a club head weight of at least 254 grams. A third golf club of the set of three or more golf clubs can be a 5-iron-type golf club with a club head weight of at least 260 grams. In further embodiments, the lengths of each golf club can be increased by at least approximately 3% from those lengths listed in Table 11 and Table 12. In yet further embodiments, both the club head weight can be increased and the length of the golf club can be increased to optimize consistent club gapping.

TABLE 11

Exemplary Golf Clubs Optimized for Consistent Club Gapping
with High Center of Gravity Steel Shafts.

	Length	Club Head	Swing
Club #	(inches)	Weight (grams)	Weight

2	39.25	240	D0
3	38.75	247	D0
4	38.25	254	D0
5	37.75	260	D0
6	37.25	266	D0
7	36.75	273	D0
8	36.25	280	D0
9	35.75	288	D0
PW	35.50	296	D2
UW	35.50	297	D4
SW	35.25	305	D4
LW	35.00	314	D6

TABLE 12

Exemplary Golf Clubs Optimized for Consistent Club
Gapping with High Center of Gravity Graphite Shafts.

	Length	Club Head	Swing
Club #	(inches)	Weight (grams)	Weight

2	39.25	245	C9
3	38.75	251	C9
4	38.25	257	C9
5	37.75	261	C9
6	37.25	266	C9
7	36.75	271	C9
8	36.25	277	C9
9	35.75	282	C9
PW	35.50	289	D1
UW	35.50	289	D3
SW	35.25	298	D3
LW	35.00	306	D5

Increasing the length of the golf clubs and/or increasing the weight of the club heads of the set of golf clubs can advantageously facilitate more uniform and/or consistent club gapping for many players between the iron-type golf clubs. The increased weight and/or increased length can allow for recovering distance that may be lost due to inexperience or mis-hitting with the iron-type golf clubs, particularly the long iron-type golf clubs. By positioning the center of gravity higher on each shaft, the set of iron-type golf clubs can have a substantially similar swing weight, which can advantageously facilitate a consistent swing feel among the iron-type golf clubs. An additional benefit is that the increased weight of each club head can allow for additional optimization of the club head, such as positioning the center of gravity of the club head for higher launch, or for increased inertia for more forgiveness on mis-hits.
Returning to the drawings, FIG. 7 illustrates a flow chart for a method 700, which can be used to provide, form, and/or manufacture a set of golf clubs and/or a set of shafts in accordance with the present disclosure. Method 700 is merely exemplary and is not limited to the embodiments presented herein. Method 700 can be employed in many different embodiments or examples not specifically depicted or described herein. In some embodiments, the procedures, the processes, and/or the activities of method 700 can be performed in the order presented. In other embodiments, the procedures, the processes, and/or the activities of method 700 can be performed in any suitable order. In still other embodiments, one or more of the procedures, the processes, and/or the activities of method 700 can be combined or skipped.
Referring to FIG. 700, method 700 can include block 710 for providing a set of golf clubs. In many embodiments, the set of golf clubs can be similar or identical to set of golf clubs 600 (FIG. 6). The set of golf clubs of method 700 can include a two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. Each golf club of the set of golf clubs of method 700 can be similar or identical to golf club 500 (FIG. 5). Each golf club of the set of golf clubs of method 700 can include a shaft. Each shaft can be similar or identical to shaft 100 (FIG. 1) and/or shaft 400 (FIG. 4). Each shaft can be an elongate body having a tip end, a butt end, a midpoint, and a center of gravity, wherein the elongate body extends between the tip end and butt end. The center of gravity can be located closer to the butt end than to the tip end and can be located a distance from the midpoint that is greater than or equal to approximately 6.0% of a distance from the midpoint to the butt end. In some embodiments, the set of golf clubs of method 700 can include three or more golf clubs each having a different loft angle. In other embodiments, the set of golf clubs of method 700 can include four or more golf clubs each having a different loft angle. In a number of embodiments, the center of gravity for each shaft of the set of golf clubs of method 700 can be greater than or equal to approximately 9.0% of a distance from the midpoint to the butt end. In still further embodiments, center of gravity for each shaft of the set of golf clubs of method 700 can be greater than or equal to approximately 11.0% of a distance from the midpoint to the butt end. In many embodiments, a swing weight of each golf club of the set of golf clubs of method 700 can be the same or substantially similar.
In some embodiments, the set of golf clubs of claim 700 can be provided by performing one or more sub-processes. Providing the set of golf clubs can include block 720 of providing a set of shafts. Each shaft of the set of shafts can be configured for an iron-type, wedge-type, or hybrid-type golf club having a different loft angle. In many embodiments, the set of shafts of block 720 can include two or more shafts, as described above in connection with block 710, and can be provided via annealing, forging, milling, machining, molding, and/or other processes, where the portions of the shafts can be a single piece or can include several pieces coupled together such as via welding, brazing, and/or adhesives. In some embodiments, steel shaft can be provided through annealing such that the thickness of the wall of each shaft is greater at the butt end than at the tip end, so as to position the center of gravity closer to the butt end. In other embodiments, graphite shafts can be provided by weaving carbon fibers and impregnating filler materials, such as tungsten or steel, so as to position the center of gravity closer to the butt end. In certain embodiments, providing the set of shafts can include providing untrimmed shafts. In certain other embodiments, providing the set of shafts can be include trimming each shaft to a suitable lengths for assembly in iron-type golf clubs.
Providing the set of golf clubs can include block 730 of providing a set of club heads. The set of club heads can include two or more club heads. The club heads can be provided via casting, forging, milling, machining, molding, and/or other processes.
Providing the set of golf clubs can include block 740 of assembling each shaft of the set of shafts with each club head of the set of club heads. Each shaft of the set of shafts and each club head of the set of club heads can be assembled through welding, brazing, adhesives, and/or other processes.
Although the golf clubs and shafts configured for consistent club gapping have been described with reference to specific embodiments, it will be understood by those skilled in the art that various changes may be made without departing from the spirit or scope of the present disclosure. For example, to one of ordinary skill in the art, it will be readily apparent that blocks 710, 720, 730, and/or 740 of FIG. 7 may be comprised of many different procedures, processes, and activities and be performed by many different modules, in many different orders, that any element of FIGS. 1-7 may be modified, and that the foregoing discussion of certain of these embodiments does not necessarily represent a complete description of all possible embodiments.
As the rules to golf may change from time to time (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and/or governing bodies such as the United States Golf Association (USGA), the Royal and Ancient Golf Club of St. Andrews (R&A), etc.), golf equipment related to the apparatus, methods, and articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the apparatus, methods, and articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The apparatus, methods, and articles of manufacture described herein are not limited in this regard.
While the above examples may be described in connection with an iron-type golf club and a hybrid-type golf club, the apparatus, methods, and articles of manufacture described herein may be applicable to other types of golf clubs such as a wood-type golf club or a putter-type golf club. Alternatively, the apparatus, methods, and articles of manufacture described herein may be applicable other type of sports equipment such as a hockey stick, a tennis racket, a fishing pole, a ski pole, etc.
Additional examples of such changes have been given in the foregoing description. Other permutations of the different embodiments having one or more of the features of the various figures are likewise contemplated. Accordingly, the disclosure of embodiments is intended to be illustrative and is not intended to be limiting. It is intended that the scope of the present disclosure shall be limited only to the extent required by the appended claims.
The golf clubs and shafts discussed herein may be implemented in a variety of embodiments, and the foregoing discussion of certain of these embodiments does not necessarily represent a complete description of all possible embodiments. Rather, the detailed description of the drawings, and the drawings themselves, disclose at least one preferred embodiments, and may disclose alternative embodiments.
All elements claimed in any particular claim are essential to the embodiment claimed in that particular claim. Consequently, replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims, unless such benefits, advantages, solutions, or elements are expressly stated in such claim.
Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and/or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and/or limitations in the claims under the doctrine of equivalents.

Claims

What is claimed is:

1. A set of shafts for golf clubs comprising:

two or more shafts each configured for an iron-type, wedge-type, or hybrid-type golf club having a different loft angle;

wherein:

each shaft of the set of shafts comprises an elongate body, a tip end, a butt end, a midpoint, and a center of gravity, wherein:

the elongate body extends between the tip end and the butt end;

the center of gravity is located a first distance from the midpoint;

the first distance is greater than or equal to approximately 6.0% of a second distance from the midpoint to the butt end; and

the center of gravity is located closer to the butt end than to the tip end.

2. The set of shafts for golf clubs of claim 1, wherein the two or more shafts comprise three or more shafts each having a different loft angle.

3. The set of shafts for golf clubs of claim 1, wherein the two of more shafts are each configured for a different golf club ranging from a 1-iron-type golf club to a 9-iron-type golf club.

4. The set of shafts for golf clubs of claim 1, wherein the two or more shafts are configured for one or more iron-type clubs and one or more wedge-type clubs.

5. The set of shafts for golf clubs of claim 1, wherein the two or more shafts are each configured for a different golf club ranging from a 2-hybrid- to a 5-hybrid-type golf club.

6. The set of shafts for golf clubs of claim 1, wherein, for each shaft, the first distance is greater than or equal to approximately 9.0% of the second distance.

7. The set of shafts for golf clubs of claim 1, wherein, for each shaft, the first distance is greater than or equal to approximately 11.0% of the second distance.

8. The set of shafts for golf clubs of claim 1, wherein each shaft comprises a wall comprising steel, and a thickness of the wall is greater at the butt end than a thickness of the wall at the tip end.

9. The set of shafts for golf clubs of claim 8, wherein, for each shaft, the thickness of the wall at the tip end is between approximately 0.008 and 0.018 inches, and the thickness of the wall at the butt end is between approximately 0.015 and 0.030 inches.

10. The set of shafts for golf clubs of claim 1, wherein each shaft comprises a wall comprising carbon fiber, wherein the wall is impregnated with a weighting material between the midpoint and the butt end, wherein the weighting material has a higher density than the carbon fiber.

11. A set of golf clubs comprising:

two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle;

wherein:

each golf club of the set of golf clubs comprises:

a shaft comprising an elongate body, a tip end, a butt end, a midpoint between the tip end and the butt end, and a center of gravity, wherein:

the elongate body extends between the tip end and the butt end;

the center of gravity is located a first distance from the midpoint;

the center of gravity is located closer to the butt end than to the tip end.

12. The set of golf clubs of claim 11, wherein the two or more golf clubs comprise three or more golf clubs each having a different loft angle.

13. The set of golf clubs of claim 12, wherein a first golf club of the three of more golf clubs is a 3-iron-type golf club having a club head weight of at least 247 grams, a second golf club of the three of more golf clubs is a 4-iron-type golf club having a club head weight of at least 254 grams, and a third golf club of the three of more golf clubs is a 5-iron-type golf club having a club head weight of at least 260 grams.

14. The set of golf clubs of claim 11, wherein the two or more golf clubs are each a different golf club ranging from a 1-iron- to a 9-iron-type golf club.

15. The set of golf clubs of claim 11, wherein the two or more golf clubs are one or more iron-type clubs and one or more wedge-type clubs.

16. The set of golf clubs of claim 11, wherein the two or more golf clubs are each configured for a different golf club ranging from a 2-hybrid- to a 5-hybrid-type golf club.

17. The set of golf clubs of claim 11, wherein, for each golf club, the first distance is greater than or equal to approximately 9.0% of the second distance.

18. The set of golf clubs of claim 11, wherein, for each golf club, the first distance is greater than or equal to approximately 11.0% of the second distance.

19. The set of golf clubs of claim 11, wherein a swing weight of each golf club within the set of golf clubs is the same.

20. The set of golf clubs of claim 19, wherein the swing weight of each golf club is between approximately 205.00 and 216.50 in-oz.

21. A method comprising:

providing a set of golf clubs comprising two or more golf clubs each being an iron-type, wedge-type, or hybrid-type golf club having a different loft angle;

wherein:

each golf club of the set of golf clubs comprises:

a shaft comprising an elongate body, a tip end, a butt end, a midpoint, and a center of gravity, wherein:

the elongate body extends between the tip end and the butt end;

the center of gravity is located a first distance from the midpoint;

the center of gravity is located closer to the butt end than to the tip end.

22. The method of claim 21, wherein providing the set of golf clubs comprises providing the set of golf clubs with three or more golf clubs each having a different loft angle.

23. The method of claim 21, wherein providing the set of golf clubs comprises providing each golf club of the set of golf clubs with the first distance being greater than or equal to approximately 9.0% of the second distance.

24. The method of claim 21, wherein providing the set of golf clubs comprises providing each golf club of the set of golf clubs with the first distance being greater than or equal to approximately 11.0% of the second distance.

25. The method of claim 21, wherein providing the set of golf clubs comprises providing each golf club of the set of golf clubs wherein a swing weight of each golf club within the set of golf clubs is the same.