This invention generally relates to golf clubs, and more specifically to a golf club head having a multi-material construction.
Typical iron club heads are solid with flat hitting faces and generally configured as either muscle back or cavity back clubs. Traditionally, all irons were configured as muscle back clubs, which are smooth at the back with low offset, a thin topline and a thin sole, and a topline that has a thickness that is similar to the thickness of an upper blade portion of the clubs. Cavity back irons have a hollowed out back and the club head mass is redistributed to the sole and the perimeter of the club head, which moves the center of gravity lower to the ground and rearward. The weight distribution makes the iron launch the ball higher and increases rotational moment of inertia thereby lowering its tendency to rotate on mis-hits and enlarging the sweet spot.
Some muscle back irons have an interior hollow section, such that the club resembles a muscle back on the outside but the interior hollow section alters the club's mass characteristics. One example is U.S. Pat. No. 4,645,207 to Teramoto et al. The Teramoto patent discloses a set of iron golf clubs in which the iron club is cast by the lost wax method, and the back member is welded at the back of the face member to form a hollow section between the back and face members. As the club changes from a longer iron to a shorter iron, the hollow section is gradually decreased to zero and the sole width is gradually decreased.
Another example is U.S. Pat. No. 4,754,969 to Kobayashi. The Kobayashi patent discloses a set of golf clubs wherein each one-piece club head includes a hollow section behind the striking face. Each of the club heads is made of a stainless steel by, for example, a lost wax casting process. The material of each of the face portions of the club heads is then annealed.
Another example is U.S. Pat. No. 7,126,339 to Nagai et al., which discloses utility golf clubs, which generally include a hollow interior.
There remains a need in the art for an improved iron-type golf club that provides greater flexibility in manufacturing processes and materials while incorporating complicated geometries.
The present invention is directed to iron-type golf clubs. The inventive iron-type golf club provides a club head that improves the discretionary mass placement to optimize the center of gravity location and moment of inertia values utilizing a multi-material construction, while providing more manufacturing flexibility.
In an embodiment, an iron-type golf club head includes a body, at least one body weight member and a hosel weight member. The body includes a body member and a sole member that is coupled to the body member along at least a portion of a perimeter of the sole member. The coupling forms an interface between the body member and the sole member. The body defines a lower cavity that includes an upper opening and that is entirely defined by the body member and the sole member, and the upper opening is defined by a flange, wherein a portion of the flange extends from a rear surface of a face of the body and overhangs a portion of the lower cavity. The lower surface of the sole member forms at least a portion of a sole surface of the golf club head. The body defines a receptacle that extends across the interface and at least one body weight member is coupled to the body in the receptacle. The lower surface of the body weight member forms a portion of the sole surface of the golf club head. The hosel weight member is coupled to a proximal end of a hosel of the body. The body comprises a first material and the body weight member comprises a material that has a specific gravity that is greater than a specific gravity of the first material, and the hosel weight member comprises a material that has a specific gravity that is greater than the specific gravity of the first material.
In another embodiment, an iron-type golf club head includes a body and a plurality of weight members. The body includes a body member and a sole member that is coupled to the body member along at least a portion of a perimeter of the sole member. The coupling forms an interface and a lower surface of the sole member forms at least a portion of a sole surface of the golf club head. The body defines a plurality of receptacles that extend across the interface. The plurality of weight members are coupled to the body in the receptacles and the lower surface of each weight member forms a portion of the sole surface of the golf club head. A portion of the sole member is sandwiched between a weight member and the body member.
The present invention also includes a method of constructing an iron-type golf club head. The method includes forming a pre-form body that has a perimeter weighted upper portion and a solid muscle back lower portion. An elongate slot is formed in the pre-form body and an elongate sole member is formed and coupled to the body member in the slot. At least one receptacle is formed across an interface between the body member and the sole member. At least one weight member is formed and coupled to the sole member and the body member in the receptacle.
In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
The present invention is directed to golf clubs having heads that include multi-material construction. The inventive construction utilizes golf club heads constructed of at least three different metallic materials, with one of the materials interposed between two others. Several embodiments of the present invention are described below.
Other than in the operating examples, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moments of inertias, center of gravity locations, loft and draft angles, and others in the following portion of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear with the value, amount, or range. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Furthermore, when numerical ranges of varying scope are set forth herein, it is contemplated that any combination of these values inclusive of the recited values may be used.
Referring to
Sole portion 30 of body member 12 extends between leading edge 40 and a trailing edge 42 in a fore/aft direction and between the heel and toe of club head 10. The sole surface of golf club head 10 is provided by a combination of the lower surfaces of sole portion 30, sole member 14, and body weight members 16. In particular, a lower surface of sole member 14 forms a central, elongate portion of the sole surface of golf club head 10 and lower surfaces of body weight members 16 form central portions at the heel and toe ends of the sole surface of golf club head 10.
Sole member 14 is included in golf club head 10 and simplifies the construction of the golf club head so that a wider selection of manufacturing processes are available for constructing golf club head 10. In particular, in an example, body member 12 may be constructed from a forged material even with the construction of golf club head 10 that includes a lower cavity 44 that is defined by sole portion 30 of body member 12 and sole member 14. Lower cavity 44 includes an upper opening, defined by a flange 46 of body member 12, so that lower cavity is opened to upper cavity 21.
Flange 46 is formed as an integral portion of body member 12 and a portion of flange 46 overhangs lower cavity 44. As shown in
The lower end of lower cavity 44 is closed by sole member 14. As a result, lower cavity 44 is an opened cavity that is fully defined by body member 12 and sole member 14. Preferably, the body member 12 and sole member 14 are constructed from the same material so that they may be easily coupled, such as by welding.
Body weight members 16 are disposed at the heel and toe ends of club head 10. In the present embodiment, each of weight members 16 is constructed with a material that has a higher specific gravity than that of both body member 12 and sole member 14. For example, body weight members 16 may be constructed from a material such as tungsten or a tungsten nickel alloy and brazed into receptacles formed in a steel body member 12 and sole member 14. Alternatively, a lower density alloy that still has a higher specific gravity than the material of body member 12 and sole member 14, such as a 10 g/cc density tungsten alloy, may be utilized for body weight members 16 so that they may be welded into the receptacles. Combinations of different density weight members may also be incorporated.
Golf club head 10 also includes hosel weight 18. Hosel weight 18 is coupled to hosel 32 of body member 12. Hosel weight 18 may be a member that is coupled to a proximal end of hosel 32 so that it replaces a portion of the hosel, as shown, or the hosel weight may be constructed as a weight plug that is coupled to body member 12 inside, or below, a shaft bore of hosel 32. Preferably, hosel weight 18 is constructed from a material that has a higher specific gravity than the material of body member 12 and it may be weldable, brazed or mechanically coupled to body member 12. For example, body member 12 may be constructed from steel and hosel weight 18 may be constructed of a 10 g/cc tungsten alloy that is welded to the proximal end of hosel 32, as shown in
As shown in
Back plate 20 is coupled to rear surface 38 of face 22 and covers a portion of rear surface 38 that is disposed between topline 28 and flange 46 of body member 12. Preferably, back plate 20 is spaced from the upper opening into lower cavity 44 so that back plate 20 does not close any portion of lower cavity 44. Back plate 20 is coupled to rear surface 38, such as by adhesive, and may be used to tune the final weight and/or to alter the vibration characteristics of the completed golf club head 10.
Referring now to
After pre-form 52 is created, a machining process is performed to create the geometry of lower cavity 44 in the sole portion 56 of pre-form 52, shown in
The machining process is preferably performed by extending a machine tool into sole portion 56 from the sole surface side. For example, using a mill, and removing an elongate portion of sole portion 56 to create a cavity. The depth of the machine tool may vary throughout the cavity to create the overhanging flange 46 and the upper opening. For example, the machine tool is extended into, and through, sole portion 56 to create the upper opening, and the machine tool is extended only partially into sole portion 56 to cut the underside of flange 46. The machining of the lower cavity and the hosel bore result in the construction of the body member 12.
A separate sole member 14 is constructed and is coupled to body member 12, illustrated in
Sole member 14 is shaped to fit inside the lower opening of the lower cavity, and is coupled to body member 12 so that the lower opening is closed, as shown in
After sole member 14 is mounted in body member 12, receptacles are preferably machined into the sole. As shown by the exploded view of
Referring now to
Sole portion 100 of body member 92 extends between leading edge 104 and a trailing edge 106 in a fore/aft direction and between the heel and toe of club head 80. The sole surface of golf club head 80 is provided by a combination of the lower surfaces of sole portion 100 of body member 82, sole member 84, and body weight members 86. Weight members 86 are located further aftward in sole portion 100, as compared to the golf club head 10, so lower surfaces of body weight members 86 form aft portions of the sole surface of golf club head 80 at the heel and toe ends of the sole surface.
Body member 82 is preferably constructed from a forged material and golf club head 80 includes a lower cavity 108 that is defined by sole portion 100 of body member 82. Lower cavity 108 includes an upper opening so that lower cavity is opened to upper cavity 91, but does not include an overhanging flange. In the present embodiment, lower cavity 108 is shaped so that face 92 has portions with different thicknesses. For example, an upper portion of face 92 adjacent upper cavity 91 has a first thickness T4 that is different than a thickness T5 of a lower portion of face 92 adjacent lower cavity 108. As shown in
Body weight members 86 are disposed at the heel and toe ends of club head 80, intersect trailing edge 106 and are spaced from leading edge 104. A portion of sole member 84 is sandwiched between weight member 86 and face 92. Each of weight members 86 is constructed with a material that has a higher specific gravity than that of both body member 82 and sole member 84. For example, body weight members 86 may be constructed from a material such as tungsten and brazed into pockets formed in a steel body member 82 and sole member 84. Alternatively, a lower density alloy may be utilized that still has a specific gravity that is greater than the material of the body member, such as a 10 g/cc density tungsten alloy, may be utilized for body weight members 86 so that they may be welded into pockets in the steel body member 82 and sole member 84.
Golf club head 80 also includes hosel weight 88. Hosel weight 88 is coupled to hosel 102 of body member 82 and is constructed from a material that has a higher specific gravity than the material of body member 82. Hosel weight 88 may be a generally annular member that is coupled to a proximal end of hosel 102, as shown, or the hosel weight may be constructed as a weight plug that is coupled to body member 82 inside a shaft bore of hosel 102.
The construction of golf club head 80 is similar to that of golf club head 10. In particular, a pre-form is constructed, preferably by forging, that includes a solid sole portion. The lower cavity is then machined into the sole portion so that it includes both upper and lower openings, and a hosel bore is machined into the pre-form resulting in the construction of body member 82. Sole member 84 is coupled to body member 82 so that it closes the lower opening of the lower cavity, thereby completing the construction of lower cavity 108 and the body of golf club head 80. Next, receptacles 110 are machined into the sole. Receptacles 110 are machined so that they extend across an interface between sole member 84 and body member 82 and include a heel receptacle and a toe receptacle. After receptacles 110 are created, the steps of installing weight members 86, hosel weight 88, and back plate 90 are performed to create the complete golf club head 80.
In the present embodiment, weight members 86 are positioned at the aft edge of sole surface, i.e., the trailing edge, so that the mass of weight members is located as far aftward as possible. Each receptacle 110 is formed partially in each of body member 82 and sole member 84 so that each weight member 86 is coupled to both body member 82 and sole member 84 after weight members 86 are installed.
As illustrated in
Back plate 90 is coupled to rear surface 97 of face 92 and covers a portion of rear surface 97 that is disposed between topline 98 and lower cavity 108. Back plate 90 is coupled to rear surface 97, such as by adhesive, and may be used to tune the final weight and/or to alter the vibration characteristics of the completed golf club head 80. Back plate 90 may also extend into lower cavity 108 so that it covers a larger portion of a rear surface of the face.
A golf club head similar to golf club head 80 having alternative body weight locations will be described with reference to
Sole portion 138 of body member 122 extends between a leading edge 142 and a trailing edge 144 in a fore/aft direction and between the heel and toe of club head 120. The sole surface of golf club head 120 is provided by a combination of the lower surfaces of sole portion 138 of body member 122, sole member 124, and body weight members 126.
Receptacles 146 are formed in body member 122 and sole member 124 for weight members 126 after sole member 124 is coupled to body member 122. Each receptacle 146 is formed partially in each of body member 128 and sole member 124 so that each weight member 126 is coupled to both body member 122 and sole member 124 after weight members 126 are installed.
Weight members 126 are located further forward, toward a ball-striking face, than previous embodiments. In the present embodiment, weight members 126 are spaced from both leading edge 142 and trailing edge, but a portion of sole member 124 is sandwiched between an aftward surface of the weight member and an aft portion of sole portion 138 of body member 122.
Referring now to
With the exception of the weight member construction and placement, each of the embodiments of
Properties of 4-irons, i.e., iron-type golf clubs having a loft of 22° and a lie angle of 61°, having constructions shown in the examples illustrated in
In a first example, illustrated in
In a second example, illustrated in
Hosel weight member 165 is generally constructed as a solid cylindrical member that is coupled to a hosel portion of body member 165. The parts may be coupled by welding (such as conventional welding or friction welding), brazing, or mechanical couplings (such as threaded interfaces or press fitting), as appropriate for the material. After the parts are coupled, a bore is machined into the hosel weight and the hosel portion.
In a third example, illustrated in
In a fourth example, illustrated in
In a fifth example, illustrated in
As illustrated in Table 1, a comparison between 4-irons of known golf club irons, shown as comparative examples 1 and 2, are compared to examples of golf club heads of the present invention. The dimensions that are included correspond to the measurements that are shown in the schematic of
While it is apparent that the illustrative embodiments of the invention disclosed herein fulfill the objectives stated above, it is appreciated that numerous modifications and other embodiments may be devised by those skilled in the art. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments, which would come within the spirit and scope of the present invention.