JPH0449987A - Golf club assembling method - Google Patents

Abstract

PURPOSE: To eliminate any adverse effect of a shaft seam on characteristics of a bending force and a twisting force of a club shaft by adjusting the shaft to a hitting face of the club head in a prescribed direction decided by a position of the shaft seam and fixing the shaft and the club head to each other by a prescribed method. CONSTITUTION: When a club shaft is rotated, the presence of a seam 28 allows a worker to easily understand change in a force necessary for holding the shaft in a warped state from the difference between the bending characteristics of the shaft. This method can decide a circumferential position of the seam 28 without any crushing test of the shaft and a user can physically mark the outside of the shaft so as to find the position of the seam 28. After finding the seam 28, an assembler coats epoxy resin on the bottommost part of the shaft end 18 or inside a socket 22 and inserts the shaft 18 in the socket of the club head. In inserting it, the assembler notices the position of the seam 28 and positions the shaft seam to a desirable, preset club head and a face 24.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to golf club assembly, and more particularly to golf club assembly utilizing longitudinally extending seams.

BACKGROUND OF THE INVENTION A golf club is comprised of an elongated shaft having an upper end that forms a handgrip, and a club head having a ball-striking surface is attached to the lower end of the shaft.

The ball striking surface is typically off-center with respect to the longitudinal axis of the shaft, and the radial distance between the point of ball impact on the head surface and the shaft axis creates torsional forces on the shaft, as well as Generates a directional bending force.

In order to improve the consistency and performance of golf clubs, considerable effort has been expended toward techniques for balancing clubs and adjusting the bending characteristics of shafts. A typical example of this type of development is shown in US Pat. No. 4,203,598. Golf club seam geometry and technology has been the subject of significant research, and typical disclosures of this type are shown in US Pat. Nos. 1,942,445 and 2,074,986.

In order to improve the performance of batting clubs, the problem of alignment of the axis of the Radhosel to the club with the club shaft has been addressed, and in this regard, US Patent No. 317,698
No. 7 discloses a device for improving club assembly.

Prior to making golf club shafts from metal and synthetic materials, club shafts were formed from pieces of wood glued together.
This wood club shaft technology is known to vary the physical characteristics of the shaft by using different types of wood at various circumferential locations on the shaft; disclosures of this type are shown in U.S. Pat. has been done.

To date, by far the best golf club shafts are made of metal, but materials such as fiberglass, graphite, etc. are also employed. Such shafts have much greater strength than wooden shafts, are more durable than wooden shafts, and can produce consistent functional work. In the manufacture of such non-wood shafts, a single longitudinally extending seam is employed to maintain the cylindrical shape of the shaft, and the golf club shirt forming technique is described in U.S. Pat.
No. 445, No. 2,074,986, and No. 2,177,970. Golf club shaft manufacturing technology has advanced to the point where the shaft seam is no longer visible from both the exterior and interior of the hollow shaft, and the presence of the seam is not visually discernible from the exterior of the shaft.

Most golf club seams are butt welded, especially on metal shafts, where the shaft is formed by rolling the shaft stock into a tapered, substantially cylindrical shape, and The ends are in opposing relationship and butt welded together to maintain the shaft profile. This welding operation is carried out precisely so that the seam is not visible; the presence of the seam affects the torsional and bending properties of the shaft. For example, the location of the seam adds stiffness to the lateral bending properties,
Affects the torsional properties of the shaft relative to the shaft axis. Thus, the shaft seam affects the physical properties of the shaft and its deflection and recovery upon ball strike. Such shaft characteristics affect ball trajectory to a considerable extent.

To the best of the inventor's knowledge, there are currently no golf club manufacturers who assemble the shaft and head of a golf club by aligning the shaft seam with the club or with the ball hitting surface of the head in a predetermined manner. . Most golf club shafts and heads are assembled by inserting the lower end of the shaft into a cylindrical recess configured in the hosel of the club head and using epoxy to hold the shaft within the hosel recess of the club head. It will be done.

The shaft and head are assembled regardless of the rotational position of the shaft relative to the head and regardless of the position of the shaft seam adjacent the head relative to the ball striking surface of the head. Thus, current golf club manufacturers do not have in mind the relationship between the seam and the golf club striking surface, and even though it is desirable to relate the shaft seam to the head striking surface, such orientation does not necessarily reflect the relationship of the shaft seam with respect to the shaft. This is very difficult to achieve because the position cannot be determined easily.

Therefore, because the shaft and head are haphazardly assembled relative to the position of the shaft seam, many golf clubs do not allow the ball to hook or slice in response to the forces applied to the club upon impact with the ball. It has a "built-in" reaction. Only if the seam happens to be positioned in a neutral position,
Such inherent characteristics can be eliminated from the club. Even in a set of matching clubs, the seams of each club shaft will most likely meet the striking surface of the associated golf club head in a different angular relationship, subjecting each club in the set to bending and twisting. These characteristics work against the golfer's desire to produce different results for individual clubs. Avid golfers and professional golfers often find a "favorite" club that they feel is right for them, and often use an assortment of clubs that achieve consistent results.

Although previously unrevealed, this consistency between a variety of different clubs in an uneven set is that the club shaft seam is oriented toward the club head in a manner that virtually eliminates shaft seam reaction on club manipulation. This seems to be due to the fact that

It is an object of the present invention to provide a method for assembling a seamed golf club shaft and head that can achieve predetermined torsional and bending characteristics of the club during use.

Another object of the present invention is to provide a golf club having a seamed shaft in which the seam is associated with the club head in a manner that eliminates the negative effect of the shaft seam on the bending and torsional force characteristics of the club shaft. be.

Further, it is an object of the present invention to align the shaft seam with the club head so that the seam is in a neutral position with respect to the ball hitting surface of the head so as to eliminate the reaction force of the club shaft that adversely affects the flight of the hit ball. Another object of the present invention is to provide a golf club having a seamed shaft.

Furthermore, another object of the present invention is to determine the position of the shaft seam by
To provide a golf club having a seamed shaft that is matched to the ball hitting surface of the club in a predetermined manner to correct the deviation of an individual user's golf swing.

Furthermore, it is an object of the present invention to have seamed shafts attached to heads and to provide consistency of club operation across the set by creating a physical relationship between the seams of each club shaft that is consistent across a set of clubs. To provide a set of a plurality of golf clubs pre-oriented to have bending and twisting characteristics.

To practice the invention, it is first necessary to locate the seam of a seamed golf shaft. Golf club shafts typically have a tapered profile with a reduced diameter end attached to the club head. The shaft seam that occurs during the manufacturing of most club shafts is
It extends longitudinally of the shaft and is substantially consistently associated with the circumferential contour of the shaft throughout its length. That is, the rotational position of the seam relative to the shaft axis remains substantially constant over the length of the shaft.

Placing a shaft seam around a hollow shaft is often difficult due to the typically butt weld type technique used to form the seam.

An acceptable way to find the seam is to place such a shaft under bending stress while rotating it about its axis, and the deflection properties of the shaft during bending and rotation are such that the bending properties depend on the position of the seam. It's easy to understand because it changes. In this way, the position of the shaft seam can be precisely measured.

After locating the shaft seam, its location is marked and the seam is aligned with the ball striking face of the head in a predetermined manner when the club head is assembled onto the lower end of the shaft. Typically, the hosel of the head has a socket that has a diameter slightly larger than the diameter of the lower end of the shaft to closely receive the lower end of the shaft, and the shaft and head assembly allows the shaft to fit into the hosel socket. Attaching is done by using epoxy glue.

When positioning the shaft seam relative to the club's striking face, it is typically desired to position the seam in a neutral position with respect to the club's striking face and the forces applied to the club when the head contacts the ball. By neutral position, we mean aligning the seam with the club's striking surface such that the effects of the club seam on the bending and torsional properties of the shaft do not adversely affect the flight of a struck ball. Experience has shown that the preferred location of the shaft seam is on the back side of the club relative to the direction of club movement during a normal club swing when hitting a ball. Thus, in the best case, the shaft seam will be positioned 180 degrees opposite the direction of movement of the club head during the club swing. However, if you place the seam on the front side of the club,
In other words, it is also possible to position the seam in the direction of swing movement, by positioning the seam at a 90° angle to either the back or front of the club.
It is believed that a neutral recoil is created that has little negative effect on ball motion.

By locating all the seams in the shaft of a set of golf clubs, whether wood or iron, or both, each club has the same bending and torsional characteristics, and the user can This will ensure similar response and recoil of the club regardless of whether you use it.

The stiffness of the club shaft adjacent to the welded seam allows the adverse effect of relating the position of the club seam obliquely to the club's striking surface to overcome swings in a particular golfer's golf swing. many golfers
has an incorrect golf swing that causes the ball to hook to the left or slice to the right due to improper movement of the club head relative to the ball. By positioning the shaft seam relative to the club head, it is possible to create a golf club with a few unique hooks, or slices, built into the club, allowing the seam to be tailored to a particular golfer's golf swing. By fitting the club head in a way that compensates for shake, the club can be custom made for a particular golfer and the effects of an improper swing can be minimized. Similarly, if a golfer's swing changes slightly with the use of a wood set or iron set, the position of the shaft seam relative to the club head may
Each club can be custom made for a specific golfer.

The above-mentioned advantages and objects of the invention will become apparent from the following description and the accompanying drawings.

EXAMPLES The concepts of the present invention are utilized in a conventional golf club designated IO. Such a golf club basically consists of an elongated tapered shaft 1 with a club head 14 attached to the lower end.
Consists of 2. The golf club has a hand grip 16 at the upper end of the shaft, and the lower end of the shaft is shown at 18, which is secured to the club head.

The present invention can be applied to either wood or iron, and the provided golf club 10 is a 6-iron with a typical structure. The club head 14 has a longitudinally extending hosel 20 having a socket 22 configured therein for receiving the lower end 18 of the shaft 12. Epoxy may be used to bond the shaft into the socket, and diametrically extending pins may be employed. The club has a hitting surface 2 where the ball hits the ball.
4, this ball striking surface often has horizontally extending lines and is usually textured to increase frictional contact with the golf ball. The lower end of the ball hitting surface 24 is
Although it has a roughly straight profile, it is usually constituted by edges 26 with a slightly convex shape. Of course,
The angle of the ball striking face 24 relative to the axis of the shaft varies depending on the type of club.

Shaft 12 is typically made of steel and its tapered profile consists of steps of decreasing diameter from handgrip 16 to lower end 18 . The steel golf club shaft is formed by rolling a strip of steel into a circle, and the edges of the shaft stock are typically electrically butt welded to create a seam 28 and a continuous circumference. Seam 28 extends the entire length of the shaft and is substantially parallel to the axis of the shaft. That is, the circumferential position of the seam relative to the axis of the shaft remains substantially constant throughout the length of the shaft. After welding, the shaft is subjected to various sizing and secondary operations, and the method of forming the shaft does not form part of this invention.

The present invention is implemented in a golf club shaft manufactured by conventional techniques utilizing a longitudinally extending seam 28.

Although the majority of golf club shaft 12 is made of metal, it should be understood that the concepts of the present invention can be practiced with club shafts made of other materials, such as synthetic compositions.

Graphite, fiberglass, boron, and other synthetic materials are used to form club shafts, and the manner in which the shafts of such materials are constructed often results in some type of seam or other artifact. The inventive concept provides for such club shafts having the equivalent of a "seam";
For example, shafts made of "seamless" tubing having columnar regions with different longitudinal physical properties than the rest of the circumference of the shaft can also be implemented; There are three types of deformations that cause changes to the circumference of the shaft, and in this application we use the term ``1 seam'' to refer to this circumferential area of the shaft.

The presence of shaft seam 28 affects the bending and torsional properties of the shaft. During the welding or gluing process, the metal of the club shaft adjacent to the seam is heated and the shaft material adjacent to the seam otherwise has a different molecular structure and other physical properties than the surrounding area of the rest of the shaft. The very presence of the seam disturbs the integrity around the shaft. The seam thus stiffens the shaft adjacent the seam 28, thereby affecting the lateral bending behavior of the shaft and also affecting the torsional and elastic properties of the shaft as it recovers from bending and twisting. effect. Seams are these asymmetrical features of golf club shafts, and the present invention overcomes this asymmetrical feature.

In the practice of the invention, shaft seam 28 faces club head 14 and, in particular, faces 24 and edges 26 in a predetermined manner.
Head towards. Thus, the recoil of the golf club 10 upon hitting and swinging the ball is determined so that the club consistently hits the ball consistently. A set of golf clubs assembled in accordance with the present invention is consistent for all clubs and the golfer can expect the same results from each club as long as the club swing and contact with the ball are correct.

In previous golf club assembly techniques, the shaft seam 2
The positional relationship between 8 and the golf club ball hitting surface 24 has not been stated or recognized. Part of this problem is due to the fact that it is virtually impossible to determine the location of seam 28 using conventional club manufacturing techniques. Seam manufacturing techniques have become so advanced that the seam 28 is not visible from the outside of the shaft nor from the inside. Perhaps because the eye cannot see the seam, golf club manufacturers assume that the position of the shaft seam relative to the head is unimportant, and perhaps even golf club assemblers realize that the shaft has a seam. Not yet.

Although it would be possible to determine the location of the metal shaft seam with acids that corrode the interior of the club, such a partially destructive test is undesirable, and Applicant has developed a non-destructive method for locating the shaft seam, as shown in FIG. Adopt a system.

Shaft seam finder 30 consists of a cylindrical tube 32 held rigidly in a vise or other support member. tube 3
A pair of ball bearings 34, 36 are positioned within 2 in axially spaced relationship. The spacing between bearings 34.36 is 25.4cm to 30.48C
The ID is in the range of 10 to 12!'. The bore of the inner race of the bearing is slightly larger than the diameter of the thick end of the shaft 12 before handgrip 16 is attached, and the shaft is placed in the finder 30 shown in FIG.

The wide diameter end of the shaft 12 is positioned within the bearing 34.36 and the outer end 18 is deflected by hand to bend the shaft 2.54 an (1≠n) from its normal straight profile. Then, use your fingers to rotate the shaft in one direction or the other. As the club shaft is rotated, the change in force required to maintain the shaft deflected is readily apparent to the operator due to the presence of the seam 28 and the difference in the bending characteristics of the shaft. In this manner, the circumferential position of the seam 28 can be determined without destructive testing of the shaft, and the user can
Physical markings may be made on the outside of the shaft to indicate the location of the shaft.

After locating the seam 28, the assembler applies epoxy to the lowest portion of the shaft end 18 or within the socket 22.
Insert the shaft 18 into the socket of the club head. Upon insertion, the assembler will note the position of the seam 28 and position the shaft seam relative to the desired, predetermined club head and surface 24.

Referring to FIG. 5, a top view of a typical golf club for a right-handed golfer is shown, showing in dotted lines the arc of the club head during a correct golf swing. The arrow indicates the direction in which the club head will move when the ball is hit, and the direction of the arrow in FIG. 5 will indicate the front side of the club.

That is, the club ball hitting surface 24 is placed on the front side of the club,
The front side of shaft 12 is that portion of the shaft that faces the direction of club movement during a golf swing. The “rear side” of the shaft 12 is 180° relative to the front side of the shaft.
is positioned.

Experience has shown that in most instances the preferred location of shaft seam 28 is on the rear side of the shaft with respect to the direction of movement of the club during the swing. Seam 2
This position of 8 places the seam in a fairly neutral position with respect to the club's ball-striking surface 24 and edge 26, and this neutral position does not give the ball any wobbling during flight in either the slice direction or the hook direction. Eliminate the bending and twisting characteristics of the rub. The seam 28 may be placed on the front side of the shaft, since this position is also neutral to the ball hitting surface of the head. However, it has been found that maximum distance is achieved by positioning the stiffest portion of the shaft, seam 28, on the rear side of the shaft.

When the seam 28 is positioned at 90° between the front and rear sides of the shaft, this position is also a neutral position with respect to the head ball-striking surface 24, but these positions can be either on the rear side or the front side. It should be understood that both are not equally desirable.

The concept of the present invention can be used with either woods or irons, and by placing the shaft seam 28 in the same position relative to the associated club head striking surface, uniform bending of a set of different clubs is achieved. characteristics are achieved and different installations between clubs are eliminated. The ball hitting characteristics of a golf club are the shaft seam 28 and the head ball hitting surface 24.
In order to achieve a conscious deflection of the ball's path, seam 2 is
It is possible to intentionally point the ball at the ball hitting surface of the club. Thus, if a golfer knows that his or her swing with a particular club has a consistent deviation from a normal swing, the seam 28 of that particular club can be adjusted in a predetermined manner to the related club head striking surface. This gives the club the property of directing the golfer's ball motion. Similarly, a golfer with a through hook or slice may find that his clubs do not consistently align the shaft seam of each club with respect to the neutral position between the shaft and the head, resulting in a consistent hook or slice. Alternatively, a golfer with a slice may wish to construct it in a manner that helps straighten the ball's motion.

Avid golfers and professional golfers try and use many clubs and often find one club that they feel they consistently hit better than others.

Such clubs became popular probably because the shaft seam happened to be aligned with the club's striking face in a manner that produced the best results for that particular golfer. However, clubs are usually sold in sets where the golfer buys all woods or all irons at the same time, and due to the fortuitous way in which golf club shafts and heads are traditionally assembled, there are many different types of clubs in one set. Uniform results are not obtained between rubs. The present invention overcomes heretofore unknown aspects of golf club assembly methods.

It will be appreciated that modifications to the inventive concept will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

[Brief explanation of drawings]

1 is a rear view of a golf club utilizing the present invention; FIG. 2 is an elevational view of the golf club according to the present invention as viewed from the right side of FIG. 1; and FIG. 2 is a cross-sectional plan view of the golf shaft of FIG. 2 taken along the cross section ■-■; FIG. 4 is a cross-sectional view of the golf shaft of FIG. 2 taken along the cross section IV-IV; FIG. 6 is a top view of a golf club utilizing the present invention showing the trajectory of motion of the club head; FIG. 6 is an enlarged partial cross-sectional detail view of a club head attached to a shaft according to the present invention; FIG. , a cross-sectional view of an apparatus for locating shaft seams. φ Golf club, shaft, club head, hand grip, lower end 20 ・ ・ 22 @ φ φ hosel, socket, ball hitting surface, edge

Claims (10)

[Claims] (1) a shaft having a circumference, an axis, a longitudinally extending seam inherently resulting from shaft manufacture, a lower end, a hosel for attaching a head to the lower end of the shaft, and a ball-striking surface having an elongated lower edge; A method for assembling a golf club, wherein the assembled golf club has a front side specified by the direction of movement of the club when hitting a golf ball, and a rear side 180° opposite the front side, comprising: (a) a shaft; locating the shaft seam adjacent the lower end relative to the circumference of the shaft; (b) orienting the shaft against the clubhead ball striking surface in a predetermined orientation determined by the position of the shaft seam; and (c) aligning the shaft and clubhead. The method for assembling the golf club, comprising fixing the golf club to each other in the predetermined manner. (2) Point the shaft seam toward the back of the golf club.
A method for assembling a golf club according to claim (1). (3) Point the shaft seam toward the front of the golf club.
A method for assembling a golf club according to claim (1). (4) Position the shaft seam 1 toward the front of the golf club.
The method of assembling a golf club according to claim 1, wherein the golf club is oriented at 80 degrees. (5) When hitting a ball, in order to correct the fact that a particular user's golf swing deviates from the correct golf club motion path due to habit, the shaft seam is adjusted to the front side of the golf club to adjust the bending and deflection characteristics of the club. 2. The method of assembling a golf club according to claim 1, wherein the golf club is assembled into a constant relationship that adjusts the . (6) The path of motion of the golfer's club head when hitting the ball habitually deviates from the correct path of motion, and the golfer uses a golf club that has a shaft with a circumference that has a longitudinal seam that inherently results from shaft manufacturing. The seam provides the shaft with bending and deflection characteristics that affect the path of travel of the golf ball after hitting the ball with the club, and the clubhead with the ball-striking surface is attached to the shaft to reduce the vibration of a golfer's swing. The method of correcting includes: (a) locating the shaft seam adjacent to the club head; and (b) modifying the shaft and seam with bending characteristics that best compensate for deflection due to the user's golf swing habits from a correct golf swing. A method for correcting swing deflection of a golfer, comprising: aligning a deflection characteristic to a club head in an orientation to provide the assembled shaft and club head; and (c) securing the shaft and club head to each other in said orientation. (7) an assembled golf club in which each club comprises an elongated shaft having a lower end and a club head attached to the lower end of the shaft, the shaft having a periphery with an elongated longitudinal seam inherently resulting from the manufacture of the shaft; In a set of golf clubs, each of the golf clubs has a front side defined by the direction of movement of the club when striking a golf ball, and a rear side 180° opposite such front side. A set of golf clubs as described above, wherein the shaft seam of each shaft of the golf club is oriented in substantially the same direction as the associated club head surface. 8. The set of golf clubs of claim 7, wherein the seam of each shaft is positioned on the rear side of the associated golf club. 9. The set of golf clubs of claim 7, wherein the seam of each shaft is positioned on the front side of the associated golf club. (10) The seams of each shaft connect the associated golf club in a certain manner such that the seams of each shaft provide the associated golf club with bending and deflection characteristics that best compensate for deflection due to the user's golf swing habits from a correct golf swing. A set of golf clubs according to claim 7, which is fitted to the golf club.