The invention generally relates to methods of making golf club components that include an electrical and a non-electrical process and clubs that include those components.
Golfers want golf clubs that give them the power to control the golf ball. For example, if a golfer can get enough spin, they can make a golf ball land on the green and roll backwards into the hole. To this end, golf clubs have grooves or score lines that impart spin and can aid in other benefits such as channeling water.
One possible way to form a club face is electrical discharge machining, which involves using an electrode to flow current across a dielectric between the electrode and the workpiece to remove material. For example, U.S. Pat. No. 4,964,641 to Miesch, U.S. Pub. 2012/0071269 to Rahrig, and U.S. Pub. 2002/0025861 to Ezawa each report a club face with electrical discharge machined features and U.S. Pub. 2013/0072321 to Morales mentions machining a cell lattice for a golf club by electrical discharge machining.
Unfortunately, electrical discharge machining requires time and expense. The dielectric fluid must be washed and replaced between each pulse of current and some parts and materials of the instruments are consumables that must be re-supplied with regular usage. Electrical discharge machining has shortcomings that relate to the finished product, as well. Electrical discharge machining gives little control over intrinsic material properties such as grain or hardness. Also, electrical discharge machining is associated with a characteristic re-solidified “white zone” overlaying a re-hardened layer on the surface of the workpiece. These layers may include undesirable martensite, crystals that guide fracturing, or stress risers.
The invention provides methods of making a component for a golf club by shaping a workpiece by one process and also shaping the workpiece by electrical discharge machining. A process such as forging or casting can shape the gross morphology of the workpiece and material can be removed by an electrical process to form desired features or textures. Since the piece is not formed entirely by electrical discharge machining, a designer has control over intrinsic properties of the workpiece material and surface. For example, metal grain can be influenced by forging, or high stress areas of a club head—such as a face-sole transition—can be formed without electrical discharge machining if it is desired to exclude the martensite or re-hardened layer from those parts of the club head. The components can be made rapidly with low costs by shaping the workpieces with a non-electrical process and rapidly performing electrical discharge machining only on desired areas (e.g., grooves can be stamped into face inserts and surface texture applied electrically). Thus a golf club component can benefit from electrical discharge machining in a production method that can be rapid and affordable while giving designers control over material properties.
In certain aspects, the invention provides a method of making a component for a golf club head. The method includes obtaining a workpiece comprising a material such as a metal, forming the workpiece by a first process, and removing material from the workpiece by a second process. The second process includes using an electrode to flow a current across a dielectric separating the workpiece from the electrode. The workpiece is used in making a golf club.
The first process may be casting, forging, stamping, or machining. Forming the workpiece by the first process may include introducing grooves into the ball-striking face or otherwise shaping the workpiece with a result that at least a portion of a surface of the workpiece deviates from a plane. The second process may provide a surface texture on the grooves. The second process can form dimples, holes into a surface of the component, or other hard-to-form features. The first and second process can be performed in any order, simultaneously (precisely or overlapping), or in an alternating pattern.
In some embodiments, the workpiece provides a ball-striking face of the golf club head. In certain embodiments, the golf club head is a wedge-style club head.
In related aspects, the invention provides a golf club head with a club head body having a face, a sole, a toe, a heel, and a hosel extending upwards from a heel-side of the club head body when the club head is at address. A part of the club head body is formed by a first process, with material having been removed from the part by a second process that includes using an electrode to flow a current across a dielectric separating a workpiece from the electrode.
The invention provides methods for making a part for a golf club head. Methods of the invention include forming the part by a first process and a second process, where one of the processes includes electrical discharge machining (EDM).
Second process 121 may be accomplished by EDM. EDM, sometimes colloquially also referred to as spark machining, spark eroding, burning, die sinking or wire erosion, is a manufacturing process whereby workpiece 105 is shaped using electrical discharges (sparks). Material may be removed from workpiece 105 by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric liquid and subject to an electric voltage. One of the electrodes is called the tool-electrode, or simply the ‘tool’ or ‘electrode’, while the other is called the workpiece-electrode, or ‘workpiece’ and is provided by workpiece 105.
When the distance between the two electrodes is reduced, the intensity of the electric field in the volume between the electrodes becomes greater than the strength of the dielectric, which breaks, allowing current to flow between the two electrodes. As a result, material is removed from both the electrodes. Once the current flow stops, new liquid dielectric may be conveyed into the inter-electrode volume enabling the solid particles (debris) to be carried away and the insulating properties of the dielectric to be restored. Adding new liquid dielectric in the inter-electrode volume is commonly referred to as flushing. Also, after a current flow, a difference of potential between the two electrodes is restored to what it was before the breakdown, so that a new liquid dielectric breakdown can occur.
There may be different approaches to EDM such as, for example, wire EDM and die-sink EDM. In wire EDM, a continuously replaced wire is used as an electrode. In die-sink EDM, a set of electrodes having different sizes, shapes, etc. may be used during the same EDM operation in order to obtain a desired feature. In die-sink EDM, the electrode may mimic a negative of a desired shape of the part. The electrode may be advanced toward the part along a single direction (e.g., along the z-axis). The electrode used in die-sink EDM may have complex geometries. Thus EDM is a method of removing material from workpiece 105 by using a tool electrode. EDM may be referred to variously as sinker EDM, cavity type EDM, cavity EDM, volume EDM, spark machining, spark eroding, spark burning, die sinking, or wire erosion, any of which may be suitable for inclusion in second process 121. EDM may be found discussed in U.S. Pat. No. 6,979,795 to Kaneko; U.S. Pat. No. 6,403,910 to Stang; U.S. Pat. No. 4,310,742 to Pfau; U.S. Pat. No. 4,114,015 to Vasiliev; U.S. Pat. No. 3,814,893 to Helms; U.S. Pat. No. 3,614,372 to Dulebohn; and U.S. Pub. 2002/0096497 to Jariabek, the contents of which are incorporated by reference. Any suitable instrument may be used for EDM. An exemplary instrument is the Sodick AP3L Sinker EDM Machine sold by ACI Machine Tool Sales, LLC (Lawrenceburg, Ky.).
In some embodiments, method 101 includes using first process 111 to “rough in” groove 117 on workpiece 105 as shown in
Since EDM is used in second process 121, steps such as milling, cutting grooves, laser cutting marks, or even sand blasting can be avoided, if that is desired. It may be found that such steps introduce stress risers to a greater degree than EDM and thus the effects of those stress risers is inhibited by use of EDM for finishing. It will be appreciated that stress risers include locations where stress is concentrated and can be associated with cracks including very fine cracks or fissures.
Since EDM is used second process 121, it may found that method 101 provides for the rapid machining of unique surface geometries that cannot be done (rapidly or at all) with conventional casting, forging, or machining techniques alone.
Since EDM is used second process 121, it may found that method 101 provides control over surface roughness of a golf club ball-striking face to create more (or less) ball-face friction in very precise locations on the club head.
Additionally, EDM provides a finely-tuned tool for material removal for weight distribution. For example, after forming workpiece 105 into a face component for a club head, using first process 111 to create grooves 117, then second process 121 can be used to remove pockets of material from the back of the face piece. If material is removed from the top-center area of the back, the effect will be to distribute mass of the club head down and towards the perimeter, which lowers a club head center of gravity and increases a moment of inertia about an axis that is vertical when the club head is address. Weight removal patterns that can be accomplished by methods of the invention are shown in SELECTIVELY DECONSTRUCTED COMPONENT FOR GOLF CLUBS, U.S. patent application Ser. No. 13/489,154 to Beno, et al., filed Jun. 5, 2012.
Further, use of EDM provides a technique for providing mounting features such as ledges, feet, “tangs”, bendable tabs that deform to hold the face in a club head body, or other features. Such features may be found discussed in U.S. Pat. No. 8,491,412 to Roach (see, e.g.,
One beneficial application of the invention is to provide a club head in which EDM is used to create desired features but not used in those portions of a club head that are subject to maximum stress. For example, it may be desired to have a club head with a ball-striking face in which grooves 117 include edges 125 that are textured by EDM. However, it may be found that certain zones of a club head are subject to maximum stress during use.
Methods of the invention can be used to provide a golf club component with any of a variety of features.
Methods of the invention can thus be used to form desired features such as to shape edges, form grooves, flatten features (e.g., to provide a flat front or back), give textures, avoid stress risers in high stress zones. Methods of the invention can be used to create other features and shapes such as face with curves to provide, for example, bulge or roll. Methods of the invention can be used to produce one or more roll radii such as, for example, a club head such as may be found described in GOLF CLUB HEAD WITH OPTIMIZED MOI AND/OR ROLL RADIUS, U.S. Pub. 2013/0029780 to Beno, the contents of which are incorporated by reference.
In some embodiments, methods of the invention are used to introduce combinations of features (e.g., grooves and punches) to a component for a golf club head. For example, it may be found that one machining process is well-suited to introducing grooves or score lines, but not well-suited to introducing punches. It may also be found that a combination of grooves and punches provides the best surface finish for a golf club head.
First process 111 may include milling, machining, or any other suitable process. Milling is a mechanical process of using rotary cutters to remove material from a workpiece as it is advanced in a direction at an angle with the axis of the tool. In general, milling operates on the principle of rotary motion. A milling cutter is spun about an axis while a workpiece is advanced through it in such a way that the blades of the cutter are able to shave chips of material with each pass. Milling processes make many individual cuts on the material in a single run using a cutter with many teeth. The number of density of teeth is characterized as pitch. The cutter is spun at high speed, and material generally advances through the cutter slowly. The speed at which the piece advances through the cutter may be called the feed rate. It may be preferable to use a vertical mill.
In a vertical mill, the spindle axis is vertically oriented. A milling cutter is held in the spindle and rotates on an axis of the spindle. The spindle can generally be extended (or the table can be raised/lowered, giving the same effect), allowing plunge cuts and drilling. There are two subcategories of vertical mills: the bed mill and the turret mill. A turret mill has a stationary spindle and the table is moved both perpendicular and parallel to the spindle axis to accomplish cutting. Turret mills may have a quill which allows the milling cutter to be raised and lowered in a manner similar to a drill press. This type of machine provides two methods of cutting in the vertical (Z) direction: by raising or lowering the quill, and by moving the knee. In the bed mill, the table moves perpendicular to the axis of the spindle, while the spindle itself moves parallel to its own axis. Typically, larger milling machines are of the bed type and may be operated by a computerized control system. While one of skill in the art will understand that any of a number of suitable milling machines may be used, an exemplary such machine is the Vertical Machining Center sold as Model VF-2 by Haas Automation, Inc. (Oxnard, Calif.).
In practice, workpiece 105 is loaded into the milling machine. Workpiece 105 includes a material selected for inclusion in the final golf club component. Any suitable material may be used to make a golf club component including metals, polymers, composites, and other materials. Examples in include steel, aluminum, titanium, alloys, plastics, carbon fiber, or any other material. In certain embodiments, a golf club component includes 303 stainless steel.
Using a tooling or milling machine, the computer program is selected and the machine is set to operate. Workpiece 105 is loaded into the mill, which is programmed according to the manufacturer's instructions. The machine spindle spins the milling cutter while the table advances the workpiece material through the cutting area. As material passes through the cutting area of a milling machine, the blades of the cutter take swarfs of material at regular intervals. The cutting operation produces revolution marks and cuts into the material creating the grooves 117. This may be included in first process 111. Milling and machining suitable for use in first process 111 are discussed in MILLING PROCESS FOR ROUGHNESS OF GOLF CLUB FACE, U.S. Provisional Patent Application Ser. No. 61/864,925 to Moreira, filed Aug. 12, 2013.
First process 111 or second process 121 may include use of a machine (e.g., for milling or EDM) capable of automation through the use of programmed commands encoded on a non-transitory storage medium, also known as computer numeric control. Numerical control (NC) is the automation of machine tools that are operated by programmed commands encoded on a storage medium, as opposed to controlled manually via hand wheels or levers, or mechanically automated via cams alone. Most NC today is computer numerical control (CNC), in which computers play an integral part of the control. NC or CNC can be used in performing any EDM process described herein.
In modern CNC systems, end-to-end component design may be automated using computer-aided design (CAD) and computer-aided manufacturing (CAM) programs. The programs produce a computer file that is interpreted to extract the commands needed to operate a particular machine via a postprocessor, and then loaded into the CNC machines for production. Since any particular component might require the use of a number of different tools—such as drills, saws, etc.—modern machines often combine multiple tools into a single “cell”.
It will be appreciated that forming a component for a golf club by methods described herein allows for production of customized golf clubs. For example, an EDM process can be operated by CNC and can create customized features on golf club components. In certain aspects, the invention provides methods and systems for creating customized clubs. An order can be received, generated from a customer's use of a computer device to input a custom order. The order may be received at a server computer system comprising a non-transitory memory coupled to a processor. The server computer system may be used in the operation of an EDM system (e.g., via CNC) to perform methods described herein. The EDM system used according to methods described herein can provide a customized club head according to the customer's order. Producing and fulfilling custom orders is discussed in U.S. Pub. 2013/0178306 to Beno and U.S. Pub. 2013/0166405 to Mitzel, the contents of which are incorporated by reference.
A variety of methods of forming a component of a golf club head are introduced. Methods of the invention may include assembling a component with other components to produce a golf club head or finished golf club.
The component made using methods of the invention need not be a face insert and any component may be made.
As used herein, the word “or” means “and or or”, sometimes seen or referred to as “and/or”, unless indicated otherwise.
References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including references to the scientific and patent literature cited herein. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.