Patent Application
20130005502
The present invention relates generally to an innovative construction to attach high density weights to a golf club head. More specifically, the present invention relates to an innovative construction to attach high density weights to an external surface of a golf club head wherein the materials used for the high density weight doesn't lend itself well to the traditional attachment method of welding.
Ever since the golf industry has shifted away from persimmon wood type golf clubs into the modern metal wood type golf clubs, golf club engineers have always tinkered with the weight distribution of the golf club head in order to improve the performance of the golf club head. Because the modern day metal wood golf clubs are generally made out of a lightweight titanium type of material, they may not be able to shift a significant amount of weight around the golf club head. In order to address the weighting deficiencies of titanium, golf club engineers have attempted to attach higher density metallic materials to the body of the titanium golf club head.
U.S. Pat. No. 4,824,110 to Kobayashi shows one of the earlier attempts at combining different materials having different specific gravity to form a golf club head in order to adjust the weighting distribution of the golf club head. Moreover, U.S. Pat. No. 4,824,110 focuses on the usage of fiber reinforced plastic as the lightweight material while using traditional titanium or steel as the heavy weighted material. Although the usage of fiber reinforced plastic is one way to achieve significant discretionary weight within a golf club head, it does so at the expense of some other performance characteristics such as the sound of the golf club at impact.
Despite all of the design advantages associated with the fiber reinforced plastic, the usage of completely metallic golf club head is still preferred by much of the golfing public for its superior sound characteristics. The problem with the titanium material used to create a metal wood type golf club head is that it may not always join well together with materials such as tungsten, molybdenum, or zirconium; all of which have a higher density than titanium. U.S. Pat. No. 5,935,019 to Yamamoto recognizes this issue and identifies this issue by saying that “it is difficult to weld together metals of different types, and especially difficult when one of the metal is titanium or a titanium alloy.” U.S. Pat. No. 5,935,019 addresses this bonding issue by forming a metallic hollow golf club head with a sole plate molded form a light metal and formed with a fitting hole, and a weighted structure comprising a weight of a heavy metal press-fitted into a ring-shaped spacer formed of the same light metal as the sole plate, said weighted structure being fitting into the fitting hole, and the ring-shaped spacer and the sole plate being welded together.
U.S. Pat. No. 6,379,265 to Hirakawa et al. illustrates another attempt to joint two metallic materials together in a golf club head to improve the performance. More specifically, U.S. Pat. No. 6,379,265 illustrates a metal wood club including a sole plate and a weight body which is fastened to this sole plate via a spacer. A recess which accommodates the spacer and weight body is formed in a portion of the sole plate, and undercut part is formed in the inside circumferential portion of the recess, and a circumferential groove is formed in the outer circumferential portion of the weight body. When the weight body is press-fitted in the recess with the spacer in between, the spacer is forcibly engaged with the undercut part and circumferential groove, thus allowing the weight body to be firmly fastened to the recess of the sole plate of the club head.
Despite all of the attempts to attach high density weights to a metallic golf club head, most of these attempts utilize crude press-fitting techniques that do not allow the materials to bond together in a clean fashion. Moreover, the press-fitting techniques discussed above do not help limit the relative rotation of the heavy density weight with respect to the golf club head, which could lead to undesirable rattling. Hence, it can be seen from above there is a need in the field for a golf club head that is capable of joining together a heavy density metallic material together with a lower density metallic material in a manner that not only provides a clean and aesthetically pleasing joint, but also in a way that prohibits the rotation and vibration of the weight itself.
In one aspect of the present invention is a hollow metalwood type golf club head comprising a striking face portion, a body portion, a thickened sole portion, and a weight. The striking face portion is located at a frontal portion of the golf club head. The body portion is connected to an aft portion of the striking face portion. The thickened sole portion is connected to a sole cavity of the body portion, wherein the thickened sole portion has a surface area to thickness ratio of less than about 1000.0 mm; the surface area to thickness ratio is defined as the surface area of the thickened sole portion divided by a thickness of the thickened sole portion. The weight is attached to an external surface of the thickened sole portion. The golf club head has a density ratio of greater than about 2.0, wherein the density ratio is defined as a density of the weight divided by a density of the body portion. Finally, the attachment of the weight to the thickened sole portion utilizes a mechanical lock.
In another aspect of the present invention is a hollow metalwood type golf club head comprising a striking face portion, a body portion, a thickened sole portion, and a weight. The striking face portion is located at a frontal portion of the golf club head. The body portion is connected to an aft portion of the striking face portion. The thickened sole portion is connected to a sole cavity of the body portion. The weight is attached to an external surface of the thickened sole portion. The attachment of the weight to the thickened sole portion utilizes a mechanical lock, wherein the mechanical lock further comprises a protruding extension stemming from the weight, and an attachment socket located within an internal cavity of the golf club head, adapted to engage the protruding extension; wherein the protruding extension and the attachment socket engages one another to secure the weight to the thickened portion of the golf club head.
In a further aspect of the present invention is a hollow metalwood type golf club head comprising a striking face portion, a body portion, a thickened sole portion, and a weight. The striking face portion is located at a frontal portion of the golf club head. The body portion is connected to an aft portion of the striking face portion. The thickened sole portion is connected to a sole cavity of the body portion, wherein the thickened sole portion has a surface area to thickness ratio of less than about 1000.0 mm; the surface area to thickness ratio is defined as the surface area of the thickened sole portion divided by a thickness of the thickened sole portion. The weight is attached to an external surface of the thickened sole portion, wherein the weight has a mass of between about 10 grams to about 40 grams. Finally, the attachment of the weight to the thickened sole portion utilizes a mechanical lock.
These and other features, aspects and advantages of the present invention will become better understood with references to the following drawings, description and claims.
The foregoing and other features and advantages of the invention will be apparent from the following description of the invention as illustrated in the accompanying drawings. The accompanying drawings, which are incorporated herein and form a part of the specification, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Various inventive features are described below that can each be used independently of one another or in combination with other features. However, any single inventive feature may not address any or all of the problems discussed above or may only address one of the problems discussed above. Further, one or more of the problems discussed above may not be fully addressed by any of the features described below.
Like previously mentioned, the modern age metal wood type golf club head may generally be constructed out of a titanium material, to which it is difficult to weld any high density materials. Following that theme, the body portion 102 of the golf club head 100 in accordance with the current exemplary embodiment may generally be constructed out of a lightweight titanium type material for its high strength and low weight properties. The titanium material used to construct the body portion 102 may generally have a density of about 4.5 g/cc; however numerous other types of metallic material with high strength-to-weight ratio could be used without departing from the current scope and content of the present invention so long as they have a density of between about 4.0 g/cc and about 5.0 g/cc.
Weight 106, as discussed in this current exemplary embodiment of the present invention, may generally be made out of a material that has a higher density than the titanium material used to construct the body portion 102 in order to provide a more noticeable change to the weighting properties of the golf club head 100. More specifically, weight 106 may generally be constructed out of a tungsten type material have a density of about 17.0 g/cc; however numerous other materials such as molybdenum, zirconium, tantalum, brass, copper, gold, or even platinum could all be used without departing from the scope and content of the present invention so long as they have a density that is greater the density of the body portion 102 of the golf club head 100. Alternatively speaking, the material used for the weight 106 may generally have a density of greater than about 9.0 g/cc, more preferably greater than about 9.5 g/cc, and most preferably greater than about 10.0 g/cc all without departing from the scope and content of the present invention.
Given the need of the weight 106 to dramatically change the weighting properties of the golf club head 100, the requirement that the density of the weight 106 be greater than about twice that of the density of the body portion 102 will generally yield a “density ratio” of greater than about 2.0, more preferably greater than about 2.1, most preferably greater than about 2.2. The density ratio, as referred to in the current exemplary embodiment of the present invention, is defined by Equation (1) below:
Finally, the golf club head 100 shown in
The thickened sole portion 104, as discussed in this current exemplary embodiment of the present invention, may generally be formed out of the same material as the material used to form the body portion 102 of the golf club head. Having the thickened sole portion 104 formed out of the same material as the body portion 102 allows for the two components to be attached easily to one another using traditional attachment methodologies such as welding. However, thickened sole portion 104 may be formed out of a material that is substantially similar to, or completely different from the body portion 102 material without departing from the scope and content of the present invention, so long at the materials can be easily joined together.
Locking nut 208, as shown in
It is worth re-emphasizing here that the implementation of the mechanical lock together with a weldable locking nut 208 is only necessary because the weight 206 itself can not be easily welded together, requiring the addition of these mechanical components. The current invention, in order to create sufficient bond strength, utilizes both a mechanical lock mechanism with titanium components to allow welds to be used to accomplish a secure bond between the golf club head 200 and the high density weight 206.
Finally,
The surface area to thickness ratio of the thickened sole portion 404 in accordance with the current exemplary embodiment of the present invention may generally be less than about 1000.0 mm, more preferably less than about 969.0 mm, and most preferably less than about 941.0 mm; with the total surface area of the thickened sole portion being approximately 1600 mm2.
Like prior discussions have indicated, the weight 406 used in this current exemplary embodiment of the present invention may generally be constructed out of a heavy weight high density material that carries significant mass. More specifically, the weight 406 discussed in this current invention may generally have a mass of between about 10 grams and about 40 grams, more preferably between about 15 grams and about 25 grams, and most preferably about 20 grams. Having such a heavy weight 406 may generally mean that the momentum generated by the weight 406 during a golf swing could cause significant stress on the attachment mechanism. Hence, in order to ensure that the weight 406 is securely attached to the golf club head 400, all while preserving the minimal amount of weight for the remainder of the golf club head 400, the present invention has constructed a thickened sole portion 404 to which the weight 406 can easily attach.
Similar to the locking nut 208 shown above in
In addition to the “anti-rotation components” used to enhance the bond of the mechanical lock between the weight 706 and the thickened sole portion 704,
The integration of the plurality of weld grooves 724 into the thickened sole portion 704 and the locking nut 708 can be shown more clearly in
Other than in the operating example, or unless otherwise expressly specified, all of the numerical ranges, amounts, values and percentages such as those for amounts of materials, moment of inertias, center of gravity locations, loft, draft angles, various performance ratios, and others in the aforementioned portions of the specification may be read as if prefaced by the word “about” even though the term “about” may not expressly appear in 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 form 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.
It should be understood, of course, that the foregoing relates to exemplary embodiments of the present invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.
