JPS63216584A - Iron golf club - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] (Industrial application field) This invention relates to an iron golf club.

In the iron golf club of the present invention, no bridge is provided between the blade and hosel of the club head, and the blade and hosel are adjacent to each other. And luck to the golf ball II! The weight distribution of the golf club has been altered to increase the mass available for Im transmission. The hovill is provided with a hole of a constant diameter that passes through the sole of the golf club head, and the club shaft is fixed in this hole.

The iron golf club according to the present invention has the following features.

(1) This iron golf club head is provided with a short hosel at the heel end of the blade. The hosel is formed from the same gold vAl material as the blade and is a continuous and integral member thereof, completely covering the heel end of the blade from top to bottom. There is virtually no bridge at the gate between the blade and the hosel, and no bridge at all below the hosel. The hosel extends from a location above the top of the blade downward to the sole of the clubhead. The hosel is provided with a passageway or hole of constant diameter extending downwardly from the top of the hosel and through the sole. The shaft of the golf club is fixed within the hosel and extends completely to the sole.

(2) The sole of this iron golf club head is designed to be wide enough at the heel to allow a hole with a constant diameter of 378 inches (0,9531) to pass through the hosel and heel. This hole can receive the shaft completely up to the sole of the club head.

(3) In this iron golf club head, the mass of the hosel part removed by shortening the hosel or the part removed by eliminating the bridge between the reblade with the hole and the hosel is It has been moved to the part of the golf club that contributes to transmitting the motion M to the golf ball. A golf club with this altered mass distribution has at least a 15% increase in mass available for momentum transfer compared to a conventional iron golf club having the same loft. It should be noted that by substantially eliminating the bridge between the blade and the hosel, the ff1ffi that would otherwise be used to form the bridge can be freely relocated to the blade section.

(4) Due to the almost ideal weight ω distribution from the toe to the heel in this iron golf club head, when an impact is made with the golf ball at a point far from the center, the lateral moment of inertia is large. Thanks to maximum torque resistance (torqtlf! resis
tance') can be obtained.

(5) This iron golf club provides better feel due to the concentrated mass of the club head and the fact that the shaft extends to the sole of the club head.

We believe that the club head according to the present invention has a positive face progression.
At one time, I thought that this club head needed a positive 7-ace progression or a negative face progression.

The purpose of these designs is to improve the performance of iron golf clubs. The mass concentration that results from moving mass from the hosel and bridge to the blade itself allows the golfer to be more aware of the clubhead at any point during the swing. This translates directly into improved consistency and effectiveness in the forward swing when returning the club head to the ball.

As a result of the features described above, approximately 13 ounces of weight can be transferred from the hosel and bridge to the blade. This weight accounts for nearly 20% of the total club head weight for a 2-iron, and more than 15% of the total club head weight for pitching wedges and sand wedges. These improvements can be made without changing the overall weight of the golf club.

All golf clubs consist of three parts.

That is, it consists of a grip, a shaft, and a club head. Of these, only the club head contributes to the actual flight of the ball. The shaft and grip are important in helping the player efficiently bring the golf club to the ball. This relationship is similar to how the handle of a hammer or ax serves to carry the working part of such a tool to the workpiece.

Our analysis of iron golf clubs reveals that a conventional club head actually consists of three parts, two of which are required. The three parts are (1) the blade used to hit the golf ball;

(2) A hosel, which is a device for attaching the club head to the shaft. Hosels are a necessary evil. This is because, other than playing the role of holding the shaft, the hosel only increases ff1l and does not contribute in any way as a member that imparts momentum to the golf ball. A more effective position for the hosel is believed to be near the center of impact of the club head. A golf club with this arrangement has a center shaft.
However, according to the rules of golf, such shapes are not allowed except for putters.

Regarding golf clubs other than butter, the Rules of Golf state: The shaft and neck or socket must be aligned with the heel or at a point to the left or right of the heel when the club is viewed at address. (3) The third part is a part that has been thought to be necessary for iron golf club heads, that is, a bridge that connects the blade and hosel. The conclusion we have reached is that the bridge can be substantially removed from iron golf club heads. That is, a short hosel is molded directly onto the end of the blade and the hosel socket is formed as a constant diameter passage extending through to the sole of the club head. A shaft is secured within this passageway and extends to the sole. Conventional irons always have a bridge below the hosel, but there is no need for a bridge below the hosel at all.

Conventional golf club iron heads have a 20 to 25% @m in the hawville and bridge portions. To compensate for this, iron manufacturers design blades so that the toe is wider than the heel. This configuration moves the center of impact (sweet spot) somewhat from the hosel toward the center of the blade. The center of impact in a golf club is the point on the club face at which the ball is struck exactly without creating torque or loss in momentum transfer. Some manufacturers take the above-mentioned impact center movement a step further by adding ff to the toe at the back of the iron golf club head.
1ffi is applied. However, even toe-weighted iron golf clubs have 20% of the head weight in the hosel and bridge portions. This is less of a problem with wood clubs. This is because wood is a much lighter material compared to steel, and the wood head is so deep that the material near the socket is less important.

(Object of the Invention) An object of the invention is to reduce the amount of material forming the hosel portion and bridge portion of an iron golf club head;
The idea is to transfer a corresponding amount of weight to the blade, which contributes to the transfer of momentum to the golf ball.

To explain in more detail, the concept of the present invention is that a material of about 1.3' Ans (3747) is removed from within 172 inch (1,27 cII4) of the heel portion of the iron golf club head located on the axis of the shaft. consists of removing. The weight of the iron head is 8 for a 2 iron.
．． Considering that it varies from 5 oz (241 g) to 10.5 oz (298 g) for the wedge, the material available for movement or repositioning is 15-15 oz (241 g) of the total head weight.
20%, and the object of this invention is to relocate within the head at least 15% of the weight of the entire head.

The "Shaft-OVer-hO3O1" design used by some manufacturers, while it may seem so to the uninitiated, is actually a design used for repositioning to the impact area of the golf club. It's not about saving weight. The shorter and lighter hosel-like section is provided with a solid cylindrical section hidden inside and covered by the lower part of the shaft.

In golf clubs with traditional shaft/hosel construction, the shaft is located 1.5 inches above the hosel.
1cm) only. The hosel is provided with a hole to receive the tip of the parallel or tapered shaft.

This construction wastes material (between the hosel and the club blade). This is because not only does this add unnecessary weight, but it also experiences air resistance near the point of maximum velocity. These harmful effects are proportional to the square of the speed, so the impact is large. It is an object of the invention to reduce the height and weight of the hosel section.

In this invention, the length of the hosel that remains on the golf club is shortened to approximately 1 inch (2.54 mm), which is sufficient to secure the shaft.

More importantly, the portion of the hosel and the bridge that are omitted in this invention are the portions of the club head furthest from the blade center and are the portions that have the most adverse effect on the location of the center of impact. This is true for the iron standard lie angle, which varies from 57° to 64" and has an average size of 60".
You can understand it immediately if you consider es). In this triangle, the bowsel part is 30° from the toe of the golf club head.
It means being in a far direction. Another advantage of moving the center of impact toward the toe is that the sweet spot is moved further away from the hosel, which can cause the ball to hit the hosel inadvertently and cause the ball to veer sharply to the side of the shank. The probability of hitting a shot decreases.

Other features and objects of the invention can be understood from the embodiments described below with reference to the accompanying drawings.

(Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

When the expressions ``iron golf club'' and ``iron golf club head'' are used in Honkawa 111 or the claims, these expressions have the meaning that they normally have in the classification of golf clubs and club heads used in golf. Refers to all similar club head products other than Iron Metal.

The definition of "iron" is from Davies' Dictionary of Golf Club Terms (hereinafter referred to as the Dictionary).
of Golfino Terms' (written by Peter Avies, edition 411980)
Simon and Shasta (5iaon & 5
chuster) ).

(d) As of 1930 - A club with any iron or spool head. Nowadays, it is a club with a graded loft, lie, and shaft length, ranging from a 1-iron to a 9-iron (each traditionally Wedges and sometimes butter are also counted as irons.Since this invention concerns something other than butter, this description and the scope of the claims are 11 JI excludes butter from the definition of "iron". Regarding Hayashi! 1, other materials suitable for iron in so-called "iron bar clubs" such as graphite, steel, beryllium-copper, and other alloys are excluded. I would like to include it as well.

In this specification and in the claims, the following definition from the same dictionary is adopted for "blade".

"1n, the hitting part of an iron club head, excluding the hosel." In the same dictionary, "hosel" 12 is defined as follows:

“hosel n, &V, [an origin of Niskotlandt hosel, hoozle, houzle =
'YN tool socket with shaft shape. 'Also,
Sc, N, D,) is the verb ho
Use = "to fix in a socket or housing" is said to be the origin of the word. 1n.

The socket or neck of an iron club head. 'A "hosel" 12 in this specification and claims consists of a length of annular mechanical structure surrounding, supporting and securing a portion 14 of a shaft 16 embedded in the hosel 12. . It can be seen from the view Igi in FIG. 10 that the annular vozel 12 surrounds, supports and secures the end member 14 of the shaft 16 embedded in the hosel 12.

The hosel 12 is a socket, and while in conventional clubs the bottom of the socket is open, in the hosel 12 of the present invention the bottom of the socket is open (this means that in the - side, the bottom of the socket is open). (reducing metal parts in the hosel section of the 20, thus reducing weight).

In the front view of FIG. 10, the dashed line 22.24 can be considered a plane passing through the end of Beauville 12 drawn in this front view. Looking at the line forming the top 26 of the blade 10, it can be seen that it is almost directly connected to the hosel 12 and the dashed line 22, except for a small curved bridge 30 in between. The bridge 30 is shown shaded in FIG.
It is called. Although the clubhead shown in Figure 10 can be manufactured without a bridge, such clubheads and other It is common for metal products to be provided with the aforementioned bridge.

The line forming the sole 32 of the blade 10 is the hosel 12
and is in direct contact with the broken line 22, and no "bridge" is formed therein.The bridge 3 shown in FIGS. 7 to 13
It should be noted that having any bridge greater than 0 is of no use. Even if a third party provides a larger bridge, it is considered to be a bridge that does not imply any matrix characteristics for the purpose of patenting. This is because such large bridges serve only certain non-bridge purposes, such as aesthetics.

What is emphasized in the new club head 20 according to the present invention is that substantially no bridge 30 is provided between the blade 1o and the hosel 120. No bridge 3°tit is provided below the ho building 12. This point is one of the unique contributions of this invention to golf club irons.

Figures 3 and 4 are PING EYE.
FIG. 2 is a plan view and a front view of a club head 20a of a 5-iron. FIG. 4 shows a cross section of the hosel 12. Blade 10a is separated from hosel 12a by a large bridge 30a. As you can see from the diagram,
The line forming the top 26a of the blade 10a and the line forming the sole 32a of the blade 10a are hosel 12a.
is not in contact with One of the features of this invention that provides better distribution of small volumes in the club head consists in completely eliminating something like bridge 30a.

The smallest bridge 30b that we know of on the back of the club head 20b of a conventional iron is the fifth bridge.
Toney Penn
a) It is an iron. The iron in the figure is a 7 iron. In FIGS. 5 and 6, the bridge 30t) is shown shaded. The end of the Bozel 12b is the top 26b of this Tony Benaud iron blade 10t)
near the line forming the blade 10b and the sole 32 of the blade 10b.
It ends at the height of blade 10b above the line forming b. It can be said that the bridge 30b does not perform any essential function. Bridge 30b is not used to grip or secure a club shaft (like hosel 12b) nor is it used to strike a golf ball (like blade 10b).

Also, the bridge 30b (like the blade 10b) is not effectively positioned to impart a motion G to the golf ball.

Figures 1 and 2 show an example of a golf club (no. y1 wedge) that we designed in the past, before we came up with the idea of eliminating the bridge of the club head 20c. The bridge 30G provided between the hosel 12G and the blade 10c can be said to have an average length for irons used today. That is, there are many irons that have a length six times longer than the bridge 30c depicted in FIGS. 1 and 2. The small pill 12C is located well above the line forming the top 26c and sole 32c of the blade 10c.

In comparing the various types of iron golf clubs in this specification, the comparison will be based on the loft of the club face. This is because clubs with similar lofts typically have the same club head shape and overall club length.

For example, a typical 5 iron with a D-0 swing weight is usually molded to the following specifications.

Head weight: 267g Shaft weight: 120g Foot angle: 30° Club length: 3 fins (94 cra) Some club manufacturers vary the loft of their 5-iron within a range of ±2°. Since the loft angle affects the flight of the golf ball through the air and the distance between the lines, it is considered best to compare irons based on the loft rather than the club number.

The type of shaft 16 illustrated has an outer tube 40 formed of glazed wood and an inner tube 42 of steel or other non-wooden material joined together. This type of shaft is disclosed in commonly assigned US Pat. No. 4,470,600. End members 14 may also be used for shafts manufactured in this manner, or for shafts made of plain steel or other non-wood materials.
The end of the inner tube 42 (in the MA construction shown in the figure) has a constant outer diameter. End member 14 is snugly inserted into a passage or hole 44 in hosel 12 having a diameter of approximately 378 inches (0.953 aR). The end member 14 of the shaft 16 is adhesively fixed with an epoxy adhesive, and may also be wedged. A plastic sleeve 46 is used to cover the end of the outer tube 40 that abuts the hosel 12. Cordwhipping can also be used in place of the sleeve 46. The lower end of the hosel 12 is connected to the sole 32 of the blade 10.
It is cut into a shape that matches the height of the A plastic plug 48 is glued to the end '@14 of the shaft 16 to seal the end of the shaft. The lower end of the shaft end member 14 and the plug 48 are similarly ground to match the age of the sole 32.

In this embodiment, the end member 14 of the shaft 16 is secured within the bore 44 by adhesive.

In practice, the end piece 14 of the shaft is glued and wedged. That is, although the end member 14 and/or the hole 44 have a small taper shape of, for example, about "0.04", it is not very noticeable to the naked eye. When the term "constant diameter" is used in this specification and in the claims in connection with the shaft end member 14 and/or the T-hole 44, it means that today's tapered iron shafts are For example, at most “0.04
The aforementioned small taper of 0" is included in this. Tapered iron shafts and parallel tip shafts are both included in this. Not included in "constant diameter" are:
Some of Wilson's "Dynapower" (t+
ynapower) ”It is an iron club head.

These club heads have a dual-diameter design that extends the club head from the lug to the sole.
There is a passageway. That is, there is an upper passage which has a normal hosel diameter and functions as a hosel, and a lower passage which has a narrow diameter and leads to the sole. The lower passage has a plug formed from an elastomer. Although this plug gives an impression (11Dression) to the shaft extending to the sole, it is not actually provided. Apparently the lower passages and plugs have no other function than that of aesthetics.

The length of the hole 44 provided in the hosel 12 is 1 inch (2
, 54 am>, 1.5 inches (3.81 cm)
A hole 44 having a length greater than ) serves no purpose in properly securing the shaft 16. Therefore,
Again, 1 inch (2,54c) is considered to be sufficient.

As can be seen from the front view, the length of the hole 44 mentioned above is the same as that of the hole 4.
It is the length along the center line 50 of 4. The length of the hole 44 is
The toe end of the club head is longer than the heel end of the club head. In the front view, the length along the centerline 50 can be considered to be the average length of the hole 44.

The wedge has sufficient metal in the longitudinal direction of the hosel portion, with a hole 44 having a constant diameter of 3/8 inch (0,953 cm) and at least 1/16 inch (0,159 cm).
A sufficiently thick wall with a thickness of 1) is provided. Therefore, it has a total thickness of at least about 172 inches (1,27n). On the other hand, the irons according to this invention include a 5-iron, a 4-iron, a 3-iron, a 2-iron,
As you move up to the number 1 iron, the front and back of the hosel part becomes progressively thinner. In order to achieve the minimum required longitudinal thickness of approximately 1/2 inch (1,273>), the thickness of the club head 20 in the longitudinal direction must be kept at least 1/2 inch (1,27 cm). There is this Ming i11
When the expression "hosel" is used in the patent application and claims, it includes not only the portion surrounding the shaft portion t relative to the upper surface of the remainder of the clubhead, but also It is defined as including the part that surrounds the main part of the club head.The latter part encloses the portion of the club head 20 extending from the shaft 71 to the sole 32.In a conventional club head (
Well, there was no need to think that the main part of the club head had the function of a hosel. In other words, in conventional club heads, all hosel functions end above the top of the rest of the club head.

The improvements in this invention are even more impressive when considering the No. 1 iron. , the head of a 1 iron is approximately 2393. In the new installation a1 according to the invention, the surplus stock available for playing field transmission is the same as for wedges, which is 3. In this invention, the play draw effect of the No. 1 iron is
ve mass) is 239g, which is a 20.3% difference compared to 182g for the conventional No. 1 iron. Since the total weight remains the same, both golf clubs can be swung at the same club head speed. Therefore, 1 of this invention
According to the iron, there is a 20% greater h effect before contact with the ball! 1lffi (!tta times the speed) can be obtained.

Table 1 below shows the difference in right-handed suspension available for field transfer for all series of irons from 0-0 to D-2 swingway 1- for conventional and inventive irons. It is shown in range 943.

Table 1 Clubs Club Heads J3 to this invention Conventional play Difference Difference ff1fnl? ) Le R effect Wfl (g) - 1rit (g) (y) (%) No. 1 iron 239 219
182 37 20.32ffi 7in 24G
22G 189
37 19.63 iron 253
233 196 37 18.94
Number iron 260 240
203 37 18.35 iron
267 247 210
37 17.66 iron 274
254 217 37 17.17
Number iron 2131 261
224 37 16.58 iron
288 268 231 3
7 16.09 iron 295
275 238 37 15.5 I
Tsuji 302 282
245 37 15.1 Sando 1 Tsuji
302 282 245
37 15.1 The club head 20 has a passageway or hole 4 having a constant diameter, i.e.
4 is provided. The shaft 16 of the golf club has an end member 14 having a constant diameter, and this end member 141J is tightly inserted into the hole 44 and fixed with an adhesive. Si1? The foot 16 extends to the sole 32 of the club head 20. The small radius 12 surrounds a portion formed around the top of the hole 44 and the heel end of the blade 10.

Club head 20 has standard weights for club heads with the same loft. Because the weight distribution within the club head is different, the quality m available for transmitting the playing field to the golf ball when making a golf stroke with a club head according to the present invention is different from that of a conventional club head with the same loft and club head weight. is at least 15% larger than when using an iron club head. Conventional club heads do not have a constant diameter hole extending to the sole of the club head to receive the shaft of a golf club, and the hosel has a normal length. The hosel of a conventional club has an 11-pillar top that extends at least 2.5 inches (6,351) above the sole of the club head 20 (a distance 111t measured along the axis of the hosel). In conventional club heads, Fig. 2, Fig. 4
As shown in FIG. 6, the hosel hole in which the shaft is secured extends only part way into the sole of the club head. The holes in conventional club heads have a constant diameter or are tapered.

The sole 32 of the club head 20 according to the present invention is designed to have a sufficiently wide heel, and the hole 44 is approximately 3/8 inch (
It is possible to set R1 to a diameter of 0,953ca+).

Only the face of the iron club head and the members immediately behind the face are capable of directly transmitting momentum from the club to the golf ball. Taking a wedge as an example, the total 1ffi of this club is approximately 472 grams (approximately 16.5 ounces). The constituent members are as follows.

Head: 302g Shaft: 117g Grip: 53g Combined + 472g The average length that a conventional wedge head has along the nose of the hosel is approximately 2.5 inches (6.35 Cab). Construction for conventional club heads generally includes a shaft liner or shaft that extends the hosel to a depth of 1.5 inches (3.81 cm). In the present invention, the bore 44 provided to receive the shaft 16 serves as a hosel and has a diameter of 0.375 inches (0.953 Ca). For wedges, the length of the hole 44 is 1.2 inches (3,05 cm+>) for subsequent totals n.The removed portion of the hosel has an average outer diameter of 0.53 inches (1,35 n) and an inner diameter of 0. .375
inch (0,953c*). The weight of this part is 1
It is 8.89. An additional 18.8'J of weight is removed from the hosel section due to the removal of the area previously occupied by the nine 0.375 inch (0.953 cfR) diameter holes drilled out to receive the shaft. When you put these two parts together, you can get to the part that actually hits the ball without increasing the size of the club head! The total number of metal types that can be used to transmit l1ffi is 37! J (
13 ounces). Importantly, since the total ff1ffi of the club head remains the same, the club can be swung at the same speed and the swing weight remains the same.

Table 2 below compares the conventional single wedge head and the short hosel wedge head according to the present invention.

Table 2 Upper hosel weight Og
-199 metal ram that is shortened and remains in the hosel -20g -20LJ
Metal ff1ffl left in the hole
0g-18g motion m remaining head audience available for transmission 282g
2457 heavy stone difference
...37g...Increase rate of effective mass 37/245 x
Considering the 10G-15,1% 2 iron,
The improvements made by this invention are even more impressive. 2
The head of a number iron is approximately 246 grams. In this invention, the surplus weight available for momentum transmission is 37 g, which is the same as in the case of a wedge. The effective blade quality ω of the No. 2 iron according to the present invention is 222 g, which is a difference of 20.0% from the conventional No. 2 iron of 155 g. Since the overall weight of the golf club remains the same, both golf clubs can be shot at the same swing speed, resulting in 2? ! With irons, you can obtain more than 20% more effective luck 1u11 (product of mass and velocity) before contact with the ball.

The following Table 3 shows, for the entire series of irons, the difference in effective mass available to transfer the amount of momentum from D-0 to D-2 swingways for conventional clubs and clubs according to the invention!・It is a comparison across a range.

Table 3 Club Club head Effective mass Conventional pre-difference External type! (1 (g) - mass (g)
(Si) (%) No. 1 iron 239
215 178 37 20.82
Number iron 246 222 18
5 37 20.037ft iron 253
229 192 37 19
．． 34? ! Iron 260 23 et al.
199 37 1E1.65 iron
267 243 206 37
18.06 iron 274 2
50 213 37 17.47 iron 281 257 220
37 16.88 iron 288
264 227 37 16.39 iron 295 271 234
37 15.8 wedge 302
278 241 37 No. 15.4 wedge 302 27B 241
37 15.4 To demonstrate the effect of transferring the mass present in the hosel portion to the club face portion, the formula for the flight distance III (carry) of a golf ball can be expressed as: effective mass of the head, club head speed , must be derived as a function of the loft angle of the club and the coefficient of restitution between the golf ball and the club face.

The following symbols are used throughout the discussion and derivation of the equations below.

M - Effective quality of the club head m (oz) m - Mass of the golf ball (1,62 oz (4!+, 9 g)) Ul - Speed of the club head before impact U2 - Speed of the golf ball before impact = Ov1 - Velocity of the club head immediately after separation v2 - Velocity of the golf ball immediately after separation e - Coefficient of restitution between the ball and the club face
There are limits to the value of e II. In other words, the coefficient of restitution “e
” is limited to υ1 between O and 1.

For soft viscosity or putty-like materials, the restitution coefficient "e" is almost 0, and in the case of a perfectly elastic material, no energy is lost due to deformation, so the restitution coefficient "e"
” is 1.0. The repulsion coefficient “e” is expressed by the following formula.

■2-v1 e=-2-Ul It is not important to compare the exact value of the restitution coefficient "e". However, actual values are useful in recognizing the results obtained from such comparisons.

The following data was obtained from an actual experiment in which a stationary ball was impacted in the center with a golf club such as a driver that had almost no lift.

u1 = ioo miles/hour (II) h ) (161?
m/ll ) U2= O V =69 sph (111b/h ) V2=
139 mph (2171 m/h) Therefore, e---0,66 This value for the coefficient of restitution ia e'' will be used throughout the following discussion.If a club with a higher loft is used, then the coefficient of restitution ``e'' The value of is expected to be slightly higher due to the fact that for a club with loft there is less deformation as the impact is not centered.In the case of butter, the club head speed is much lower; It is interesting to note that the ball hardly deforms.In this case, the coefficient of restitution e is around 0.80.In the irons of the golf club head, the loft ranges from 14 degrees for the No. 1 iron to finesse The ball has various sizes up to 60 degrees, and the value of the coefficient of restitution varies depending on each club and ball combination.

The speed of a golf ball immediately after impact with the golf club is a major factor in determining how far the golf ball will fly through the air. By using golf balls of the same type, there is no need to consider the ball as a variable. The initial velocity of a golf ball upon center impact is a function of the effective mass of the club head, the weight of the golf ball, and the coefficient of restitution between the ball and the club face.

The initial velocity of the golf ball can be derived by applying the law of conservation of luck fl1m to the current situation. However, since we do not know the velocity of the club head after it leaves the ball, a second equation is required to obtain the solution. This need for a second equation is met by making a substitution from the equation for the coefficient of restitution "e". As a result, we obtain the following final formula for the initial velocity v2 of the golf ball.

1+e speed ■ and speed U1 must be expressed in the same unit, and the same applies to quality ff1m and effective quality IM.

The value of the speed U can be determined by actual testing using commercially available equipment or high-speed photography. Table 4 below shows how the coefficient of restitution "e" affects the initial velocity of a golf ball, using a driver with a club head of 7 ounces (198 seconds) and a standard weight of 11.62 ounces. Using a golf ball with (45,9g) u 1
= 100 mph (161KIA/h) and apply the above formula (V2=100(1+e)/1.2
3 = 81.2(1+e))L.

Table 4 0.0 (Pate) 81 (130KIR/h)
0.7 138 (222 touches/h) 0.5 122 (
196KIA/h) 0.8146 (to 235!R/h
)0.6 133(214b/h) 0.9154(2
481m/h) 0.66 135 (2171m/h)
1.01 G2 (261 b/h) Even for a perfectly elastic golf ball, the club head speed is 100 ph (16
The initial velocity of the golf ball on the platform of 1b/h) is 162
It is interesting to note that it does not exceed iph (261/h). For the actual condition e=0.66, the initial velocity is 135iph (217?Ca
z/h). Rules of golf
Even if a larger value of the coefficient of restitution II eII were allowed in Golf), a higher result would not be possible because a ball manufactured with a larger coefficient of restitution "e" would be brittle and more likely to break upon impact. You probably won't be able to do it.

When a golf ball leaves the club face, it becomes a flying object that flies freely. A ball's flight pattern is affected by a variety of factors, including air density, launch angle, backspin applied by the club and the lift created by this backspin, air resistance, and finally gravity. The aforementioned air resistance is due to both lift (induced drag) and geometry (detrimental drag). Lift and drag (air resistance) both vary as the square of velocity, varying constantly from the velocity of the ball when it leaves the club face, to a much smaller velocity when the ball hits the ground. Launch angle and backspin vary from golfer to golfer, and even from shot to shot for the same golfer. Therefore, determining how far a golf ball will fly depends on the appropriate atmospheric conditions (pressure, temperature, wind speed, terrain) and, if the total flight distance, including roll, is determined by the appropriate ground conditions. This is done based on the empirical formula derived from the experimental values obtained below.

The average values shown below are based on head weights of approximately 7 ounces (19
89) driver and a standard golf ball having a weight of 1.62 ounces (45.9 g) and a diameter of 1.68 inches (4,271);
August 986 Golf Digest (Got-F DI
GEST).

Ul(■ph) Average carry 10G(16
1b/h) 244 yards (223m)9
G (145k/h) 215 yards (197
m ) 80 (129 & / h) 184 yards (1687 FL) e = 0.66, M = 7 oz (
198 g) and m = 1.62 oz (45,99), the value of velocity v2 can be calculated as follows.

Since 1+e, C11 (aph) V2 (mph) V2
(fps) 10G (1611m/h) 135 (21
7Fa/h) 198(60,4i/s) 90(14F
Ja/h) 122(196KM/h) 179(
54,61/S) 8G (129fm/h) 10B (1
74b/h) 158 (48,2i/s) When the relationship between the carry in yards and the initial golf ball velocity in feet per second is graphed, it can be seen that there is a linear relationship between the two. The equation of the straight line that these average values satisfy is Average Carry in Yards = 1.5V2-53
(V2 unit is feet 7 seconds) (Average carry (77L units)) = 5.38 V
2 58.0 (V2 in units of TrL/S) This equation can be used to predict the carry of a golf ball when the loft angle of the club face is very small, ie, 20 degrees or less. For clubs with larger lofts, the velocity component normal to the club face should be used. This will be discussed below when comparing irons with a loft of 1-0.

The next article 1n is a quantitative analysis comparing short hosel irons according to the present invention with conventional irons. Here, a golfer with a low handicap
hits a 39-inch ('99cIR) 1-iron at a clubhead speed of 95 miles per hour (153 KIR/h).
Also assume that you can swing a 3 finch (94 cm > 5 iron) at a club head speed of 85 miles per hour (137/h).

Comparison loft of No. 1 iron 1--14''' (C03=0.970) U 1=
9011Elh=139fEIS(42,411/5)
Ul (valid value) = U8 = 139X O, 97 = 135
fps (41,1m/s) Effective head weight Conventional club old = 239-57 = 182G = 6.42 oz Invention club H2 = 239-20 = 219 (J = 7.72 oz e =
Use 0.66.

Vl - Initial velocity of the golf ball when using the conventional club ■2 - Initial velocity of the golf ball when using the club of this invention For the club, V1 = 179 ft/sec (54,61/s) For the club of this invention, V2 = 185 ft/sec (56,41/s) Substituting these values into the formula for "carry" yields: For clubs, Killery 1.5X 179-53” 215 yards (19
7m) In the club of this invention, carry = 1.5X 185-33 = 224 yards (2
051 difference 4. L9 yards (8.2m) and 4.2%
become.

Comparison loft of 5 iron - 30" (cos=0.866) ("1 (
effective 1fi) = tJ8 = 125X O, 866-108
feet per second (32,911/S) Effective Head Weight Conventional Club Old = 210 g = 7.41 oz Club of the Invention H2 = 247 (1 = 8.71 oz Following the same procedure as for the 1-iron) For the conventional club V 1 = 1477 e 17 seconds (44, fsm/s) carry; 167 yards (153 II+) for the club of this invention ■ 2 = 151 ft/s (4G, Om/s) carry - 114 sade ( 159m) Carry difference is 7V-do (6,4m>, 4.2%
It is.

It will be seen that these results are within the range of values experienced under practical conditions.

In the case of a sand wedge, distance is not as important as in the case of a fairway iron. However, in a Nand wedge, the saved mold skin can be transferred to the sole of the club and used as flange material. This moves the C1 impact center downward, making it much easier to launch the ball from the sand in the bunker. If you use a sand wedge as a fairway club, the trajectory of the ball will be higher, but at the same time the run to get it onto the green will not be too far. These characteristics are particularly useful on part wedge shots where not much backspin is applied to the ball.

The golf club of the present invention, which includes a short hosel 12 with a through hole and virtually no bridge 30, is based on an innovative concept and dramatically improves the efficiency of iron golf clubs. I'm letting you do it. The weight saved near the heel of the club has been moved to the bottom of the iron near the toe.

As a result, the trajectory of a properly hit ball is improved, increasing distance by 4 to 5 percent in the case of fairway irons. Sand wedges have a lower center of gravity, and of course 11
j It is more effective because the center of attack moves downward. This makes wedges more effective when hitting the ball out of sand bunkers, and it also helps shorten the run when hitting shots onto the green where you are putting from the fairway.

The embodiments described above are merely illustrative and do not limit the invention. Therefore, the iron golf club according to the present invention can be realized in any form without departing from the spirit and scope of the invention.

[Brief explanation of the drawing]

The drawings show an embodiment of an iron golf club according to the present invention and a conventional golf club head, and FIG. 1 is a plan view of a sand wedge, and FIG. 2 is a cross-sectional view of the hosel portion of FIG. 1. 1 is a front view of a non-dot wedge, FIG. 3 is a plan view of a Pingeye 5-iron, which is a conventional golf club head, and FIG. 4 is a front view of the golf club head of FIG. Figure 5 is a plan view of a Tony Bena 7 iron, which is a conventional golf club head, Figure 6 is a front view of the golf club head of Figure 5 showing a sectional view of the hosel section, and Figures 7 to 12 are An embodiment of this invention, FIG. 7 is a plan view of a No. 7 iron;
Figure 8 is a front view of the 7-iron, Figure 9 is similar to Figure 7 and is an enlarged plan view of the 7-iron, and Figure 10 is similar to Figure 8 but enlarged and shows the hosel. Figure 11 is a bottom view of the club head and part of the shaft; Figure 12 is an end view of the club head as seen from the toe; Figure 13 is the heel of the club head. FIG. 10...Blade 12...Hosel 16...Shaft 20...Club head 26...Top 30...Bridge 32...Sole 44...Hole Applicant Callaway Hila Collie Stick◆ Ninisei φ Incorporated Agent Patent Attorney Hidehiko Okada (2 others) Figure 11 Figure 6 Figure 6 Figure 7 Figure Name 8 Review

Claims (4)

[Claims] (1) Consisting of a head 20 and a shaft 16 of a golf club, the head 20 has a sole 32 and a blade 10, this blade 10 has a toe end and a heel end, and the head 20 has a sole 32 and a blade 10, and the head 20 has a toe end and a heel end. the blade 1 having a hosel 12 disposed adjacent the blade 10 at the heel end of the blade 10, the hosel 12 being formed as a metal jaw member continuous and integral with the blade 10;
0 completely covers the heel end of the blade 10 from the top 26 to the bottom, no bridge 30 is provided between the blade 10 and the hosel 12 below the hosel 12, and the hosel 12 from a position above the top 26 of the blade to the sole 3
2, that the hosel 12 has a hole 44 of constant diameter extending from the top of the hosel 12 to the sole 32, and that the shaft 16 is secured within the hole 44 and extends to the sole 32. Features iron golf clubs. (2) Consisting of a head 20 and a shaft 16 of a golf club, the head 20 has a sole 32 and a blade 10, this blade 10 has a toe end and a heel end, and the head 20 has a sole 32 and a blade 10, and the head 20 has a toe end and a heel end. The blade 10 has a hosel 12 disposed adjacent to the blade 10 at the heel end of the blade 10, and the hosel 12 is formed as a metal member continuous and integral with the blade 10.
completely covers the heel end of the blade 10 from the top 26 to the bottom, and there is substantially no bridge 30 between the blade 10 and the hosel 12, and the hosel 12 10 from a position above the top 26 of the hosel 12 to the sole 32, the hosel 12 has a hole 44 of constant diameter extending from the top of the hosel 12 to the sole 32, and the shaft 16 extends into the hole 44. An iron golf club characterized in that the iron golf club is fixed and extends to the sole 32. (3) Consisting of a head 20 and a golf club shaft 16, the head 20 has a sole 32 and a blade 10, this blade 10 has a toe end and a heel end, and the head 20 has a sole 32 and a blade 10, and the head 20 has a toe end and a heel end. The blade 10 has a hosel 12 disposed adjacent to the blade 10 at the heel end of the blade 10, and the hosel 12 is formed as a metal member continuous and integral with the blade 10.
completely enveloping the heel end of the blade 10 from the top 26 to the bottom, the hosel 12 extending from a position above the top 26 of the blade 10 to the sole 32;
a hole 4 of a constant diameter penetrating from the top of the to the sole 32;
4, wherein the shaft 16 is fixed in the hole 44 and extends to the sole 32. (4) consisting of a head 20 and a shaft 16 of a golf club, the head 20 having a bottom and a blade 10, this blade 10 having a toe end and a heel end;
The head 20 has a hosel 12 disposed at the heel end of the blade 10 adjacent to the blade 10, the hosel 12 being formed as a continuous and integral metal member with the blade 10, and the hosel 12 being formed as a continuous and integral metal member with the blade 10; 12 extends from a position above the top 26 of the blade 10 to the bottom of the head 20, the hosel 12 has a constant diameter hole 44 extending downwardly from the top of the hosel 12 and through the bottom; A bridge 30 is not provided below the hosel 12 between the blade 10 and the hosel 12, and the shaft 16 is fixed in the hole 44 and extends to the bottom of the head 20. iron golf club.