Patent Application
20170065857
Not Applicable
Field of the Invention
The present invention relates to a method of manufacturing a golf club head with improved face and hosel material properties. In particular, the inventive method bifurcates the material properties of face and hosel using a single hardening process so that the face is hard enough to maintain excellent spin via improved durability of the performance-related features and textures, and the hosel is soft enough to allow for loft and lie adjustment via bending processes.
Description of the Related Art
Wedges typically are made from softer steel materials than other irons to optimize feel during play and to allow the loft and lie of the club to be adjusted by bending the hosel. Wedges also preferably have playability characteristics such as increased spin off the face, which is mostly influenced by features like scorelines, micro-features proximate the scorelines, and textured contact surfaces. Unfortunately, the softer the material of the wedge, the easier it is for these features to wear out or deform from use. Wedge manufacturers have tried to improve the durability of face features without reducing hosel bendability by, for example, localized induction hardening or case hardening the hitting area of the face, and induction annealing the bendable region of the hosel. All of these methods require that any equipment used be localized and fine tuned for face regions of the club head, and the heating processes associated with these methods typically can only be performed on individual parts or a small batch of parts at any one time. These approaches may also require custom designed heating elements that may not be reusable for small variations in head geometry.
Therefore, there is a need for a simple, scalable method of hardening wedge faces and improving scoreline durability without reducing the bendability of their hosels or otherwise changing the clubs' bending profiles.
The methods of the present invention improve the process of bifurcating face and hosel material properties, while optimizing the heat treatment process or targeting only the critical regions of the face with a precisely controlled process. Some of these methods simplify the hardening process by heating large batches of parts and then mechanically processing them via grinding, machining, or other such processes to achieve bifurcation. For example, the full surface of a wedge can be hardened, e.g., by case hardening, to a target depth, and then specially added material stock or masking can be removed from the bendable region of the hosel to expose soft substrate. Other methods reduce the need for extra equipment and processes by using laser hardening to selectively improve the durability of critical areas of the face. In some embodiments, the method includes laser-hardening scoreline EDs, scoreline walls, and/or micro-features on the face. In other embodiments, the method includes laser hardening the whole hitting region of the face. Laser hardening is desirable because it is accurate and controllable, and does not require the creation or use of custom equipment to treat selected regions of the face.
One aspect of the present invention is a wedge comprising an upper hosel region and a face having a first, high hardness value, and a bending region with a second, lower hardness value.
Another aspect of the present invention is a method comprising the steps of manufacturing a golf club head comprising a top portion, a sole portion, a rear portion, a face, a hosel, and a build up of excess material around at least a part of the hosel, processing the face, hardening the head, removing the excess material from the hosel, and finishing the head, wherein the excess material is integrally formed with the hosel, and wherein the step of removing the excess material from the hosel occurs after the step of hardening the head. In some embodiments, the step of hardening the head may comprise at least one process selected from the group consisting of carburization, nitriding, carbonitriding, nitrocarburization, quenching, flame hardening, and tempering.
In a further embodiment, the step of hardening the head may comprise the process of carburization, and the excess material may have a thickness of at least 0.050 inch. In another embodiment, the step of hardening the head may comprise the process of nitriding, and the excess material may have a thickness of at least 0.020 inch. In yet another embodiment, the step of hardening the head may comprise the process of carbonitriding, and the excess material may have a thickness of at least 0.050 inch. In some embodiments, the step of processing the face may comprise adding a plurality of scorelines to the face, and adding secondary texture to the face proximate the scorelines. In other embodiments, the golf club head may be a wedge-type golf club head, and the step of manufacturing the golf club head may comprise a casting process.
Yet another aspect of the present invention is a method comprising the steps of manufacturing from a first material a wedge-type golf club head comprising a top portion, a sole portion, a rear portion, a face, and a hosel, masking a portion of the hosel with a second material different from the first material, processing the face, hardening the head, removing the second material from the hosel, and finishing the head, wherein the step of removing the second material from the hosel occurs after the step of hardening the head. In some embodiments, the first material may have a first thermal conductivity value, the second material may have a second thermal conductivity value, and the second thermal conductivity value may be lower than the first thermal conductivity value. In a further embodiment, the first material may be steel and the second material may be clay. In other embodiments, the second material may be a chemical barrier or a physical barrier, and the step of hardening the head may comprise at least one process selected from the group consisting of carburization, nitriding, carbonitriding, nitrocarburization, quenching, flame hardening, and tempering.
Another aspect of the present invention is a method comprising manufacturing a golf club head comprising a top portion, a sole portion, a rear portion, a face, and hosel, laser hardening at least a portion of the face, and finishing the head, wherein the face comprises a plurality of scorelines, and wherein each of the scorelines comprises an ED region and a plurality of side walls. In some embodiments, the step of laser hardening at least a portion of the face may comprise laser hardening at least a portion of the scorelines, while in other embodiments, the step of laser hardening at least a portion of the face may comprise applying laser beams at an angle with respect to at least one of the plurality of side walls. In an alternative embodiment, the face may comprise a plurality of micro-features, and the step of laser hardening at least a portion of the face may comprise laser hardening at least one of the plurality of micro-features.
Yet another aspect of the present invention is a wedge-type golf club head comprising a body comprising a top portion, a sole portion, a rear portion, a face, and a hosel, wherein the body is integrally formed from a single metal material, wherein the hosel comprises a bending region, wherein the face comprises a striking surface having a plurality of scorelines and a textured region proximate the scorelines, and wherein the bending region is more ductile than the striking surface. In a further embodiment, the bending region may be more ductile than the rest of the body, and the metal material may be a carbon steel.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
The present invention is directed to methods of selectively hardening some features of golf club heads, and wedges in particular, while preserving the bendability of other features.
In an alternative version of the first step, shown in
Once the head 10 is manufactured and the hosel region 30 is protected as described above, the face 20 is processed 120 either to rough polish, fine polish, or textured prior to plating. This step 120 may also include the addition of scorelines 22 via stamping, machining, lasering, or other means known to a person skilled in the art, if scorelines 22 are not simultaneously added to the face 20 when the head 10 is initially formed, forged, cast, or machined.
The head 10 is then subjected to a hardening treatment 130. The type of hardening treatment selected determines the minimum thickness of the excess material 40 placed around the hosel region 30 (or other regions that the manufacturer wishes to remain soft), as each hardening treatment affects the head 10 at different depths. In general, the thickness of the excess material 40 around the hosel region 30 should greater than than the depth of the hardening effect so that the hosel does not crack or crease during the bending process. For example, if the head 10 is hardened by carburization, which is most effective on lower carbon steels, the thickness of the excess material 40 should be greater than approximately 0.030-0.050 inch. If the head 10 is hardened by nitriding, a form of case hardening, then the thickness of the excess material 40 should be greater than approximately 0.020 inch. Nitriding can be performed either on raw (untreated) heads 10, or on heads 10 that have already been hardened by quenching or tempering for a greater effect. If the head 10 is hardened by carbonitriding or nitrocarburization, then the excess material 40 should be greater than 0.050 inch. If the head 10 is hardened by quenching, which generally is applied to higher carbon steels and is usually followed by tempering, the depth of the hardening effect depends on the rate of cooling during quenching, and may vary. The desired depth and length of the build-up or masked region can be determined either by testing or by FEA, which then can inform the required minimum thickness of the excess material 40.
Once the hardening step 130 is completed, the excess material 40 or masking agent 50 is removed with a tool 60 via a mechanical process 140, illustrated in
In another method 200 of the present invention, illustrated in
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
The present application claims priority to U.S. patent application No. 14/846,506, filed on Sep. 4, 2015, the disclosure of which is hereby incorporated by reference in its entirety herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14846506 | Sep 2015 | US |
| Child | 15220645 | US |
