This disclosure concerns hosel bending features for iron-type golf club head.
Golf clubs are typically manufactured with standard lie angles and loft angles. Some golfers prefer to change the standard lie angles and loft angles of their golf clubs, particularly iron-type golf clubs, by having each club head plastically bent in a post-manufacturing process. In such a bending process, it can be difficult to plastically bend the material of the club head in a desired manner without adversely affecting the shape or integrity of the hosel bore, the striking face, or other parts of the club head. In addition, advancements in materials and manufacturing processes, such as extreme heat treatments, have resulted in club heads that are stronger and harder to bend and have more sensitive surface finishes. This increases the difficulty in accurately bending a club head in a desired manner without adversely affecting the club head.
Disclosed herein embodiments of iron-type golf club heads that comprise internal features in the hosel and/or heel region of the club head that facilitate changing the orientation of the hosel bore relative to the body of the club head, as well as methods of bending such club heads.
In some exemplary embodiments, an iron-type golf club head comprises a hosel, a hosel bore for receiving one end of a golf club shaft, a front face for striking a golf ball, and a heel cavity that extends within a heelward region of the club head. As used herein, the term “heelward region” shall refer to a portion of a club head that is located distal to a first plane that is tangent to a distal (tip) end of the golf club shaft (when the club head is mounted on the shaft), and that is located heelward of a vertical plane that is perpendicular to a face plane of the club head and that passes through a heelward-most point on the front face that lies within the face plane. An exemplary method of bending the club head can comprise selecting such a club head, holding the front face of the club head stationary, and applying a torque to the hosel of the club head to plastically bend the club head in a region of the heel cavity in order to change the orientation of the hosel bore relative to the front face, thereby changing the loft and/or lie angle of the club head.
The hosel bore can have a longitudinal center axis and define a hosel bore projection region that is a cylindrical region of the club head distal to the hosel bore, is centered on the center axis, and has a diameter equal to a diameter of the hosel bore. In some embodiments, the heel cavity intersects the hosel bore projection region. In some embodiments, the heel cavity also intersects with the longitudinal center axis of the hosel bore.
In some embodiments, the presence of heel cavity in the heelward region of the golf club head reduces an amount of torque that is necessary to be applied to the hosel to change a lie angle of the club head by ±4° relative to another club head that is identical except for a lack of a heel cavity. For example, the amount of torque that is necessary to be applied to the hosel is reduced by at least 9% in some embodiments.
In some embodiments, the club head has a structural cross-sectional area defined by a plane that intersects the heel cavity within the heelward region of the club head. The structural cross-sectional area includes the load and force bearing portions of the body of the club head (i.e., excluding voids, cavities, filler material, etc.) that are included in the intersecting plane. A decrease in the structural cross-sectional area of the club head due to the presence of the heel cavity, relative to another club head that is identical except for a lack of a heel cavity, reduces an amount of torque that is necessary to change a lie angle of the club head by a given amount.
In some embodiments, the club head defines a body cavity in the body behind the front face (e.g., cavity-back irons or hollow irons with an enclosed internal void), and the heel cavity extends heelward from the body cavity. In some embodiments (e.g., cavity-back irons), the body has a rear lip that extends upward from the sole portion and extends between the toe portion and the heel portion such that the rear lip covers only a lower portion of the body cavity, and the heel cavity opens into the lower portion of the body cavity.
In other embodiments, the hosel comprises a cavity positioned distal to a shaft-end location where a distal end of a shaft is positioned when the shaft is functionally coupled to the club head. The cavity provides a reduced structural cross-sectional profile in the hosel distal to the shaft-end location to facilitate bending the hosel relative to the body.
In some of these embodiments, the hosel comprises a post that projects proximally from a distal end (bottom end) of the bore and the bore comprises an annular groove extending around the post that facilitates adjustment of the orientation of the hosel relative to the body.
In other embodiments, the bore comprises a distal end portion and a tapered portion proximal to the distal end portion. The tapered portion tapers from a proximal end to a narrowest diameter at a distal end that is adjacent to the distal end portion of the bore. The distal end portion of the bore comprises a generally cylindrical void having a diameter that is greater than the narrowest diameter of the tapered portion. In some of these embodiments, the tapered portion of the bore is centered on the longitudinal axis and the distal end portion of the bore is off-center from the longitudinal axis.
In still other embodiments, the bore comprises a first tapered portion tapering from a broadest diameter at a proximal end to a narrowest diameter at a distal end, a cylindrical portion extending distally from the distal end of the first tapered portion and having a diameter about equal to the narrowest diameter of the first tapered portion, and a second tapered portion having a proximal end extending from a distal end of the cylindrical portion and a distal end forming the distal-most end of the bore, the second tapered portion narrowing in diameter from its proximal end to its distal end.
Another exemplary method can comprise manufacturing a golf club head comprising a hosel, a hosel bore for receiving one end of a golf club shaft, a front face for striking a golf ball, and a heel cavity that extends within the heelward region of the club head; and after manufacturing the club head, plastically bending the club head in a region of the heel cavity in order to change the orientation of a centerline axis of the hosel bore relative to the front face without deforming the hosel bore or the front face.
In each of these embodiments, the presence of the heel cavity in the heelward region of the golf club head can allow the head to be more easily and accurately bent in a desired manner without adversely changing the shape or integrity of other parts of the club head, including the hosel bore and the front face.
The foregoing and other objects, features, and advantages of the disclosed technology will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
The exemplary club head 2 is a “cavity back” type club head that comprises a rear portion, or lip, 18 that extends upwardly from the sole portion 12 between the heel portion 8 and the toe portion 10 and covers a lower part of a body cavity 20 behind the face portion 16. The body cavity 20 opens rearwardly above the rear lip 18 and is defined by internal surfaces of the heel portion 8, toe portion 10, sole portion 12, topline portion 14, and face portion 16.
As shown in
The angle that the center axis 25 of the bore makes with the horizontal ground plane when the sole 12 is resting on the ground in an address position can define the lie angle of the club head 2. The angle that a line normal to the plane of the striking face 16 makes with the flat ground when the club head 2 is in the address position can define the loft angle of the club head. The loft angle can also be determined by the relationship between the center axis 25 of the bore relative to the striking face 16. Thus, by plastically bending the hosel relative to the striking face 16 of the club head 2, the lie and loft angles of the club head can be adjusted.
In order to modify the lie angle and/or loft angle of the club head 2, it can be desirable to bend the club head in the heelward region of the club head (defined by the line 29 in
In an exemplary post-manufacturing bending process, the body of a club head is placed in a gripping device, such as a vice, and a bending moment is applied to the hosel until a desired change in the lie and/or loft angles is achieved. For example, the angle α in
The plane 29 defines the heelward end of the striking face 16, such that the planar striking face can be gripped in a rigid manner toeward of the plane 29 and to be prevented from being deformed. In particular, the plane 29 is a vertical plane that is perpendicular to a face plane (i.e., a plane defined by the face portion 16) and that also passes through a heelward-most point on the face portion 16 that lies within the face plane. (In embodiments that include a non-planar face portion 16, the face plane is defined as a plane that is perpendicular to a line that is normal to the face portion 16 at the center of the face.) The location of the plane 29 can be defined in relation to a centerface of the striking face. In
The torque rod 28 can be made of material that is more rigid than the club head such that the rod does not significantly deform under an applied torque load. The rod 28 can completely or substantially completely fill the hosel bore 24 when inserted in order to distribute the applied bending moment along the inner walls of the hosel 6 with minimal stress concentrations. Because the body 4 is gripped rigidly toeward of the plane 29, plastic deformation caused by an applied torque can be isolated in the regions of the club head that are heelward of the plane 29. In addition, because the rigid rod 28 completely fills the hosel bore 24, the shape of the hosel bore can be maintained while the club head is bent.
In the embodiment shown in
In addition to reduction in structural cross-sectional area in the region between the hosel bore 24 and the plane 29, the club head 2 can also be characterized in that volume of structural material in the hosel/heel region of the club is reduced in order to make that region easier to bend. An exemplary volume of structural material can be defined by the volume of structural material of the club head that is heelward of the plane 29. Another exemplary volume of structural material can be defined as the volume of structural material within the region defined by the dashed lines 27 in
To reduce the structural cross-sectional areas and/or reduce the volume of structural material in the hosel/heel region, the club head 2 comprises a heel cavity 22. The heel cavity 22 can extend from the body cavity 20, through the heel portion 8, and to a location adjacent to the distal end portion 26 of the bore 24. The presence of the heel cavity 22 reduces the structural cross-sectional areas of the club head 2 in the heelward region between the hosel bore 24 and the plane 29. Reducing the structural cross-sectional areas in this region causes bending stress to be more concentrated in this region during a post-manufacturing bending process and reduces the amount of bending torque that is needed to be applied to the hosel to create a given amount of plastic bending in this region.
As shown in
As shown in
With regard to both the cavity back embodiment 2, and the hollow embodiment 60, by removing structural material from the heel-hosel region of the club head beneath the bore, the structural cross-sectional areas of the club head in the region of the cavity 66 can be reduced and the bending stress can be concentrated in that region, reducing the torque needed to plastically bend the club head a given amount and making the bending process easier and more accurate. Additionally, because the heel cavity is hidden within the club head, the reduction of the structural cross-sectional area in the heel-hosel region does not result in any external changes in the shape or appearance of the club head, which can be aesthetically desirable for golfers. Furthermore, the structural material removed from the heel cavity 66 can be relocated to another location on the club, such as the sole portion and/or toe portion, to provide a lower center of gravity, increased moments of inertia, or other properties that result in enhanced ball striking performance for the club head.
The hosel 6 can have an outer diameter D2 (e.g., about 12-15 mm, such as about 13.6 mm) and an inner diameter D3 (e.g., about 8-12 mm, such as about 9.6 mm) that is about equal to the diameter of the distal end of a golf club shaft. The inner diameter of the bore can decrease from D3 proximal to the tapered portion 26 to a narrower inner diameter D4 at the distal end of the tapered portion 26. As shown in
As shown in
In some embodiments, the cavity 42 has a circular cross-sectional shape perpendicular to the longitudinal center axis of the bore, while in other embodiments the cross-sectional shape of the cavity 42 can be non-circular. In some embodiments, the cavity 42 can be centered on and symmetric about the longitudinal center axis of the bore, while in other embodiments the cavity 42 can be offset from the center axis of the bore. For example, in some embodiments, the cavity 42 can have a radius R1 from the center axis in the toeward direction of from about 3.0 mm to about 7.0 mm, and a different radius R2 from the center axis in the heelward direction of from about 3.0 mm to about 7.0 mm. Desirably, the minimum radius of the cavity 42 from the center axis of the bore is at least one half of D4.
When the club head 50 is coupled to a shaft, the distal end of the shaft is positioned proximal to cylindrical portion 52 and the second tapered portion 54, leaving the distal end of the bore empty to reduce the structural cross-section areas of the hosel below the distal end of the shaft. Similarly, with the club head 30 the annular groove 32 is distal to the distal end of the shaft, and with the club head 40, the cavity 42 is distal to the distal end of the shaft, thereby providing a reduced structural cross-sectional area in the hosel below the distal end of the shaft. With each of these embodiments, the reduced structural cross-sectional area in the hosel below the distal end of the shaft allows bending stress to be more concentrated in that region of the club head, thereby reducing the force needed to bend the club head and making the bending process easier and more accurate. Concentrating the bending strain in the area below the distal end of the shaft reduces any distortion of the hosel bore in the area above the distal end of the shaft and thereby reduces adverse effects on the hosel-shaft connection integrity.
Additionally, because the groove 32, cavity 42, cylindrical region 52, and second tapered region 54 are hidden within their respective club heads in the different embodiments, the reduction of the structural cross-sectional area in the hosel region does not result in any external changes in the shape or appearance of the club head, which can be aesthetically desirable for golfers. Furthermore, the additional structural material removed from the distal end of the bore can be relocated to another location on the club, such as the sole portion and/or the toe portion, to provide a lower center of gravity, increased moments of inertia, or other properties that result in enhanced ball striking performance for the club head.
Table 1 below includes test data showing the amount of torque that is required to change the lie angle of various exemplary club heads by +4° in a post-manufacturing bending process where the body of the club head is held rigidly toeward of the plane 29 while a bending moment is applied to the hosel using the torque rod 28, as illustrated in
Tests 1-4 were performed on 4-irons having the “hollow” body style of the club head 60 shown in
Tests 5-8 were performed on 6-irons having the cavity back body style of the club head 2 shown in
For purposes of this description, certain aspects, advantages, and novel features of the embodiments of this disclosure are described herein. The disclosed methods, apparatuses, and systems should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed embodiments, alone and in various combinations and sub-combinations with one another. The methods, apparatuses, and systems are not limited to any specific aspect or feature or combination thereof, nor do the disclosed embodiments require that any one or more specific advantages be present or problems be solved.
As used herein, the terms “a”, “an” and “at least one” encompass one or more of the specified element. That is, if two of a particular element are present, one of these elements is also present and thus “an” element is present. The terms “a plurality of” and “plural” mean two or more of the specified element. As used herein, the term “and/or” used between the last two of a list of elements means any one or more of the listed elements. For example, the phrase “A, B, and/or C” means “A,” “B,” “C,” “A and B,” “A and C,” “B and C” or “A, B and C.” As used herein, the term “coupled” generally means physically coupled or linked and does not exclude the presence of intermediate elements between the coupled items absent specific contrary language.
In view of the many possible embodiments to which the principles of this disclosure may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the inventions. Rather, the scope of the invention is defined by the following claims. We therefore claim all that comes within the scope and spirit of these claims.