Patent Application
20160250524
The present invention relates to a golf club, and, more particularly, to a golf club head having a top line recess with an insert.
Golf club designers who want to make a club that is forgiving and easy to hit may turn to a multi-material or cavity-backed construction. Some such designs replace certain areas of the club head, such as the striking face or sole, with a second material that can be either heavier or lighter than the first material. By incorporating additional materials of varying densities or providing cavities and undercuts, mass can be “freed up” and used in perimeter weighting to enhance the moment of inertia. However, due to construction limitations or requirements, some of these designs inadvertently thicken the top portion of the club head.
Where a club head has a body made of a dense material such as metal, thickening the top portion of the club head raises the center of gravity. Unfortunately, this has adverse effects on playability. Some golfers find a club most useful if the center of gravity is low, getting the weight of the club head under the ball.
The present invention relates to a golf club head that has an insert at a top portion of the head. The insert can include a material that is less dense than other materials in the club head. Since the insert at the top of the club includes a low-density material, inclusion of the insert lowers the club head center of gravity. A low density insert thus offsets effects of thickening a top portion of a golf club that may arise when designing a multi-material club head or a club head with pronounced perimeter weighting. The useful mass-distribution benefits of an insert near a top portion of a club head can be increased by extending the insert and the useful vibration-dampening benefits of an insert can be increased by its mounting arrangement. Disposing an insert so that it makes contact with a back of a club head striking face may dampen unwanted vibrations and improve a club face coefficient of restitution. Extending an insert into a hosel area, heel area, toe side area, face area, back side area, or combination thereof can further lower a club head center of gravity. Additionally, extending an insert through a hosel so that it appears on a hosel side surface of the club head can improve the club head's response to fitting, which involves mounting the club head in a fitting station and bending it into a certain conformation with a cheater bar. Thus, an insert of the invention may extend through a hosel or into a toe side area, may be mounted on a back of a club face and may extend down the club face back, and may even extend down a portion of the front surface of the club face and form part of the hitting surface.
In certain aspects, the invention provides a golf club head that has a face portion with a front surface for striking a golf ball and a body portion supporting the face portion. The body portion includes a heel, a toe, a sole, and a top line. The top line includes a recess extending between the heel and the toe along the top line. The recess includes a channel having a substantially rearward-facing surface facing a substantially forward-facing surface when the club is at address. The golf club head further includes an interchangeable insert positioned within the recess, wherein the interchangeable insert includes a material with a density lower than a density of the body portion of the club head. In some embodiments, the interchangeable insert may be releasably coupled to and retained within a portion of the channel of the recess via a press fit or adhesive.
The ability to provide interchangeable inserts with a club head provides a golfer with the ability to customize a club head. This is beneficial due to the properties individual inserts. For example, in some embodiments, an interchangeable insert may provide good vibration-dampening benefits to a club head. Where a club head comes with a plurality of inserts, each of the plurality of inserts may have a different elastic modulus. A golfer can chose the insert that provides the requisite amount of vibration-dampening and insert it into the club head (e.g., to be mounted there by press-fit, golfer-applied adhesive, or other means).
In some embodiments, the body portion is formed of a first material with a first specific gravity and the interchangeable insert is formed of a second material with a second specific gravity. The second specific gravity may be different than the first specific gravity. In some embodiments, the club head satisfies the relationship IZZ≧CGZ*170, where IZZ is the rotational moment of inertia about a vertical axis and has units of g/cm2 and CGZ is the center of gravity and has units of mm. In some embodiments, the second specific gravity is greater than the first specific gravity by at least about 3. The club head may satisfy the relationship IZZ>CGZ*SG*17, wherein SG is the second specific gravity. In some embodiments, the second specific gravity may be less than the first specific gravity by at least about 3. The club head may satisfy the relationship IZZ>CGZ*SG*130, wherein SG is the second specific gravity.
In certain aspects, the invention provides a golf club head that has a face portion with a front surface for striking a golf ball and a body portion supporting the face portion. The body portion includes a heel, a toe, a sole, and a top line. The top line includes a recess extending between the heel and the toe along the top line. The recess includes a channel having a substantially rearward-facing surface facing a substantially forward-facing surface when the club is at address. The recess may be configured to receive and retain one of a plurality of interchangeable inserts within. At least one of the plurality of interchangeable inserts includes a material with a density lower than a density of the body portion of the club head. Each of the plurality of interchangeable inserts is configured to be releasably coupled to and retained within a portion of the channel of the recess via a press fit or adhesive.
In certain aspects, the invention provides an iron-type golf club head that has a face portion with a front surface for striking a golf ball and a body portion supporting the face portion and comprising a heel, a sole, a toe, and a top line. The top line has at least two internal surfaces facing inward to define a recess, and the recess extends through the hosel and is accessible from a heel-side surface of the club head and at least a portion of the recess is accessible from above when the club head is at address. The insert may use a material with a density lower than a density of the club head. The insert may be disposed within the recess.
An insert that extends through the hosel to the heel provides weight saving benefits in that it removes material from the hosel. Additionally or alternatively, including a recess for an insert extending through a hosel provides a benefit in facilitating hosel bending. Many club hits are fit to a customer's specifications by loading the club head into a fitting station machine and bending the hosel into the desired configuration. In some prior art club heads, this has led to problems with visible metal fatigue or bend lines. A recess in the hosel area provides a seed point for folding, allowing hosel material to gently redistribute during bending without straining the material. Once bent into a final position, a viscoelastic insert can be placed therein to provide a smooth finish on the hosel side surface of the club head body so that the recess does not interfere with the club head aerodynamics or trap detritus from the environment.
In certain embodiments, the insert is shaped to aid in bending of the hosel. For example, an insert may have an accordion structure. In an accordion structure, a surface of the insert has an alternating pattern of protruding flanges and grooves. The insert may have a void space within to aid in deformation, be substantially hollow (e.g., thin-walled), or be solid throughout. In a related embodiment, a recess may have at least one groove, depression, annular ring, or v-shaped notch extending along a surface to facilitate deformation.
In some embodiments, one of the two internal surfaces is provided by a back surface of the face portion and the insert is disposed adjacent to the back surface of the face portion. The insert may extend down the back surface of the face portion lower than the topline. In some embodiments, the insert is, colored, translucent, or clear. In certain embodiments, the insert is interchangeable by a golfer. A color may be included to indicate to a golfer an amount of vibration-dampening offered by the particular insert (e.g., green for comfort, red for performance).
In some embodiments, the top line includes a protrusion extending into the insert. The insert may be mounted on a surface that includes one or more micro-cavities to strengthen the attachment (micro is used as a prefix to distinguish from the cavity of a cavity-backed iron and does not limit the size of the cavities). In certain embodiments, the insert is co-molded with the club head and the material extends into the one or more micro-cavities.
The recess and the insert may extend from the heel surface, around a top line—toe transition, and into a toe-side surface. A portion of the recess along the topline may provide the two internal surfaces facing inward (e.g., substantially parallel to, and facing, each other) and have a floor surface extending between the two internal surface that faces upwards when the club is at address.
Further features and advantages of the invention can be ascertained from the following detailed description that is provided in connection with the drawing(s) described below:
The present invention is directed to a golf club head with a top line insert. The top line insert may be fashioned in a variety of ways according to the invention. For example, in one embodiment, a recess and optional insert is located in the top line of the club head and extends along the top line. In another embodiment, the recess and optional insert extends around the toe of the club head. The insert may be formed of a variety of materials. For example, the insert may be lighter than the body of the club head to adjust the center of gravity downward. Alternatively, the insert may be heavier than the body of the club head to adjust the center of gravity upward. Each of the various embodiments are discussed in greater detail below and demonstrated with representative drawings.
The recess and optional insert may be used in a variety of club heads. For example, the club head may be a long iron, a short iron, or a set including both long and short irons where the recess and optional insert is tailored to adjust the club head center of gravity and other club head properties such as moment of inertia. In addition, the present invention is contemplated for use with utility-type club heads and putter club heads.
As known to those of ordinary skill in the art, MOI is a measure of the resistance of a body to angular acceleration about a given axis, and is equal to the sum of the products of each element of mass in the body and the square of the element's distance from the axis. Thus, as the distance from the axis increases, the MOI increases, making the club more forgiving for off-center hits since less energy is lost during impact from club head twisting. Thus, moving or rearranging mass to the club head perimeter enlarges the sweet spot and produces a more forgiving club. Moving as much mass as possible to the extreme outermost areas of the club head 1, such as the heel 15, the toe 16, or the sole 13, maximizes the opportunity to enlarge the sweet spot or produce a greater MOI.
In one embodiment, the recess 20 is located in the top line 12 of the club head 1 and extends along the top line 12 from about 10 percent to about 95 percent of the top line length. The top line length LTL is defined as the distance along the top line 12 from a point P1 to a point P2. Point P1 is defined as the intersection of the golf club head 1 and a plane that is offset 5.08 mm (L1) from and parallel to a plane defined by the X-axis and the Z-axis tangent to the toe 16 at the toe's furthest point from the origin O along the Y-axis. Point P2 is defined as the uppermost intersection of the club head 1 and a plane that is parallel to the plane formed by the shaft centerline CLSH and the X-axis offset a distance of 7.62 mm (L2) in a direction closer to the toe 16.
In another embodiment, the recess extends along the top line from about 10 percent to about 50 percent of the top line length. In yet another embodiment, the recess extends along the top line from about 15 percent to about 45 percent of the top line length. In still another embodiment, the recess extends along the top line from about 30 percent to about 50 percent of the top line length. The recess may also extend along the top line from about 60 percent to about 95 percent, preferably from about 70 percent to about 95 percent.
In yet another embodiment, the recess completely extends along the top line. For example, the recess extends along 100 percent of the top line length. In another embodiment, the recess extends along the complete length of the top line and wraps around to extend into the toe of the club head. For example, the recess may extend around the top line—toe transition to a point about halfway around the toe of the club head toward the sole.
The recess 20 preferably has a volume of about 0.001 in3 to about 0.2 in3. In one embodiment, the volume of the recess is about 0.005 in3 to about 0.15 in3. In another embodiment, the volume of the recess is about 0.01 in3 to about 0.10 in3. In yet another embodiment, the volume of the recess is about 0.05 in3 to about 0.09 in3.
In relative terms, the recess 20 has a volume that is from about 0.5 percent to about 10 percent of the volume of the body 10. In one embodiment, the recess has a volume of about 1 percent to about 8 percent of the volume of the body. In another embodiment, the recess has a volume of about 2 percent to about 7 percent of the volume of the body. In still another embodiment, the recess has a volume of about 3 percent to about 5 percent of the volume of the body.
The recess 20 preferably has a depth D from about 0.254 mm to about 6.35 mm. For example, the recess may have a depth D of about 1.27 mm to about 5.08 mm. In one embodiment, the depth D of the recess is about 2.032 mm to about 3.81 mm. In still another embodiment, the recess has a depth D of about 2.54 mm to about 5.08 mm.
The recess may have a varying depth. For example, in one embodiment, a first portion of the recess has a depth D1 of about 10 percent to about 90 percent of the depth D2 of a second portion of the recess. In one embodiment, a first portion of the recess has a depth D1 about 20 percent to about 80 percent of the depth D2 of a second portion of the recess. For example, when the recess extends around the toe toward the sole, the first portion may be the portion that extends from the toe toward the sole and the second portion may be the portion that extends along the top line of the club. In an alternate embodiment, the recess has a constant depth.
In one embodiment, the insert 30 has a density that is less than the density of the club head body 10. As used herein, “density” is also intended to relate to “specific gravity”. For example, because specific gravity is merely the ratio of the density of a given solid or liquid substance to the density of water at a specific temperature and pressure, these terms are used interchangeably when discussing the relative density or specific gravity of the insert as compared to other portions of the club (such as the body) or other inserts in the club. Since the mass of the insert 30 is less than the mass removed by the recess 20, the extra mass may be replaced in more desirous locations on the club head 1. These locations may include, for example, the club head perimeter and/or the sole 13. Alternatively, no additional mass is added to the club head 1; rather, only the recess 20 and the insert 30 are used to enhance the playing characteristics of the golf club.
A body's center of gravity is determined by its weight distribution. Mass added or removed directly on the center of gravity will have no effect on the center of gravity's location. In contrast, mass added or removed far away from the center of gravity will have the greatest effect on moving the center of gravity. Removing mass from the highest areas of a club head will have the greatest effect on lowering the center of gravity. Adding the mass removed from the high areas to the bottom of the club head will further lower the center of gravity. The top line area and top-of-hosel area are the two highest vertical areas in relation to the ground plane on an iron-type head (when the head is at the address position). By removing the top line portion of the face from the casting and replacing it with, for example, a lightweight viscoelastic piece, anywhere from 20-50 grams are removed from the top of the head, depending upon the design of the viscoelastic piece. That weight is redistributed to the bottom portion of the club, lowering the center of gravity even further versus that same club head constructed entirely of a metallic material, such as steel.
MOI is also a property that is affected by mass distribution. Bodies that have mass distributed far from the center of gravity have higher MOI's about their center of gravity than bodies that have mass concentrated near their center of gravity. Removing the mass from the top of the face lowers the MOI about the center of gravity with respect to certain axes. The axis of rotation that relates to an iron's forgiveness is rotation in the heel-toe direction about the center of gravity—an axis parallel to the Z-axis. A higher MOI about this axis indicates greater resistance to twisting on off-center hits and, thus, more forgiveness. By adding the mass removed from the top line 12 back into the low-heel and low-toe areas of the club head, the reduction in MOI in the heel-toe direction due to removal of metallic material from the top line 12 is minimized.
In this aspect of the invention, the insert 30 may have a density from approximately 0.5 g/cm3 to approximately 5 g/cm3, and is preferably less than the body density by at least about 3 g/cm3. For example, a low density insert may have a density between about 1.2 g/cm3 to about 2 g/cm3. Preferably, the specific gravity of the insert in this embodiment is less than 1.5 g/cm3. Ideally, the specific gravity of the insert in this embodiment is less than 1.3 g/cm3.
In one embodiment, the density of the insert is less than the body density by at least about 4 g/cm3. In another embodiment, the density of the insert is less than the body density by at least about 5 g/cm3. The net effect of creating the recess 20 and adding the lower density insert 30 lowers the club head center of gravity (CG1 in
Suitable materials for a low density insert include, but are not limited to, nylon, glass fiber reinforced nylon, polyurethane, silicon, rubber, bulk molding compound, thermoplastics, thermosets, resins, and combinations thereof.
Table 1 shows a comparison of center of gravity locations and MOI's for a 6-iron having a urethane insert 30 to a similar club head formed completely of steel. Note that the measurements presented in Table 1 do not include any weights that may be added to the club head.
CGx, CGy, and CGZ are the x-, y-, and z-components of the center of gravity location, respectively. Ixx, Iyy, and IZZ are the MOI's about the x-, y-, and z-axes, respectively.
In the alternative, the insert 30 may have a higher density than the body. For example, the insert 30 may have a density greater than about 5 g/cm3, preferably greater than about 7 g/cm3, and more preferably greater than about 9 g/cm3, and is preferably more than the body density by at least about 1 g/cm3. For example, the insert may have a density of about 12 g/cm3 to about 15 17 g/cm3, preferably about 13 g/cm3 to about 16 g/cm3, and more preferably about 14 g/cm3 to about 15 g/cm3. In one embodiment, the density of the insert is greater than the body density by at least about 2 g/cm3, preferably about 3 g/cm3 or more, more preferably about 4 g/cm3 or more, and even more preferably about 5 g/cm3 or more.
Without being bound to any particular theory, adding mass to the top line raises the center of gravity and the moment of inertia of the club head. In particular, the net effect of creating the recess 20 and adding the higher density insert 30 raises the club head center of gravity (CG3 in
In this aspect of the invention, the recess 20 and the insert 30 may increase the club head MOI measured about an axis parallel to the Z-axis and passing through the center of gravity by at least 20 gm·cm2. That is, the club head 1 has an increase in MOI measured about a vertical axis passing through the center of gravity of at least 20 gm·cm2 compared to a substantially similar golf club head without the recess 20 and the insert 30. Thus, the recess 20 and insert 30 produce a more forgiving and playable golf club.
Suitable materials for the high density insert include, but are not limited to, powdered tungsten, a tungsten loaded polymer, and other powdered metal polymer combinations.
Table 2 shows a comparison of center of gravity locations and MOI's for a 6-iron having a tungsten-loaded polymer insert 30 to a similar club head formed completely of steel. Note that the measurements presented in Table 2 do not include any weights that may be added to the club head.
CGX, CGY, and CGZ are the x-, y-, and z-components of the center of gravity location, respectively. IZZ is the moment of inertia about the center of gravity parallel to the z-axis. Preferably, the tungsten-loaded top line insert raises the vertical center of gravity by at least about 0.0254 mm when compared to a similar club with a steel top line. In one embodiment, the tungsten-loaded polymer top line insert raises the CGZ by about 0.508 mm or more, preferably about 0.533 mm or more, and even more preferably greater than about 0.635 mm. The moment of inertia IZZ of the club head with a high density insert in the top line is at least about 1 percent greater than the moment of inertia IZZ of a similar club head with a steel top line. In one embodiment, the IZZ of a club head having a heavier insert than the body is increased by about 1.5 percent or more when compared to the IZZ of a similar club head with a steel top line.
Furthermore, a club head with a heavier top line insert (such as a tungsten-loaded polymer insert) preferably has a CGZ of at least about 0.508 mm more than a similar club head with a lighter top line insert (such as a urethane insert). For example, the CGZ of a heavier insert club head may be at least about 0.635 mm more, preferably about 0.762 mm or more, and more preferably about 0.889 mm or more, than the CGZ of a lighter insert club head.
Likewise, a club head with a heavier top line insert (such as a tungsten-loaded polymer insert) preferably has a IZZ that is at least about 2 percent more than the IZZ of a similar club head with a lighter top line insert (such as a urethane insert). For example, the IZZ of a heavier insert club head may be at least about 2.5 percent greater than the IZZ of a lighter insert club head.
The hardness of the insert will vary depending on the particular material used to form the insert. In one embodiment, the insert has a hardness ranging from about 80 Shore A to about 50 Shore D. In another embodiment, the hardness of the insert ranges from about 20 Shore D to about 50 Shore D. In an alternate embodiment, the hardness of the insert is less than about 20 Shore D.
The insert 30 may contain one or more dampening materials, which diminish vibrations in the club head, including vibrations generated during an off-center hit. Preferred dampening materials include those materials known as thermoplastic or thermoset polymers, such as rubber, urethane, polyurethane, butadiene, polybutadiene, silicone, and combinations thereof. Energy is transferred from the club to the ball during impact. Some energy, however, is lost due to vibration of the head caused by the impact. These vibrations produce undesirable sensations in both feel and sound to the user. Because the viscoelastic dampening material of the insert 30 is in direct contact with the metal club head (the vibrating body), it serves to dampen these vibrations, improving sound and feel.
In some embodiments, insert 30 may include a material that is non-Newtonian, elastic, pseudo-elastic, thixotropic, rheopectic, plastic, or super-elastic. Part or all of the insert may include a dilatant material, or shear-thickening, such as D3O or a thixotropic gel. Where the insert is housed within a recess to aid in hosel bending, the inclusion of a dilatant material may give additional strength and ball speed during play (i.e., the hosel is more bendable during fitting and stiffer during play). Shear thickening material is described in U.S. Pat. No. 8,105,184 to Lammer, the contents of which are incorporated by reference in their entirety.
Without being bound to any particular theory, a club with a high center of gravity is likely to impart more spin to the golf ball due to vertical gear effects. This is because an impact made below the center of gravity will increase the spin rate of the ball to help maximize trajectory and distance. An impact made high on the face above the center of gravity will create a higher launch angle, and the vertical gear effect will actually cause the ball to spin less. This can produce greater distance as the ball is subject to less lift or drag that a higher spin creates. Thus, in a typical club set, the higher the loft angle of the club, the lower the center of gravity (as compared to a lower loft angle club). The ability to generate more ball spin for the short irons is an important factor in the golfer's ability to control both the distance of the golf shot, and the distance the ball will roll after the ball hits the green.
However, because the material selection of insert, length, depth, and/or volume of the recess and insert of the present invention allow for adjustments to the center of gravity and moment of inertia, the present invention also contemplates a set of clubs where at least one club is equipped with a low density insert in the club head and at least one club is equipped with a higher density insert in the club head. For example, at least one long iron in the set preferably has a low density insert in the club head as described herein. The term “long irons” refers to 3 and 4 irons (and possibly 1 and 2 irons if application). The club heads on long irons have the least amount of angle, providing primarily distance. In contrast, at least one short iron in the set preferably has a high density insert in the club head. The term “short irons refers to any of the more lofted, shorter-shafted irons (usually considered to include the 8 iron through all wedges).
Due to vertical gear effects, this construction allows for more spin to be imparted to the ball from the short irons, and less spin imparted to the ball for the long irons. The ability to generate more spin in the short irons is an important factor in the golfer's ability to control both the distance of the golf shot and the distance the ball will roll after the ball hits the green.
Like the insert that fits within the recess, the insert 50 that fits over the protrusion 19 may be formed of a low density material in order to lower the center of gravity and/or MOI of the club head. In the alternative, the insert 50 may formed of a high density material in order to raise the center of gravity and/or MOI of the club head. The differences between the density of the insert and the body of the club head discussed above with respect to insert 30 also apply in this aspect of the invention.
It is possible that there are variations in size of the metallic portions of the club heads 1, 2 caused during forming and polishing. These variations typically are larger than the variations in size due to molding viscoelastic materials of the inserts 30. To aid in hiding any discrepancy between the two portions of the club head, a groove 32 may be formed in the insert 30 so the edges are visible to the user once the two pieces have been put together. This groove 32 may be created simultaneously with the rest of the insert 30, or as a secondary step. The preferred width and depth of the groove 32 are about 1 mm or less. In one embodiment, the width and depth are about 0.8 mm or less, preferably about 0.75 mm or less, and more preferably about 0.7 mm or less.
In certain embodiments, a surface of protrusion 19 functions as an internal mounting surface. Internal mounting surface may be taken to mean a surface of a part of a club head on which insert 30 is mounted such that the internal mounting surface is at least partially supporting, and therefore covered by, insert 30.
Use of an insert also has the added benefit of increasing the durability of the club head. For example, over the course of play, clubs carried together in a bag are knocked together. These impacts create marks on the club heads. The top-toe portion of the club is an area that is likely to impact with other clubs. By making that area out of a softer material, the likelihood of creating marks on the head due to club-to-club impacts is reduced.
As before, the insert in this aspect of the invention may be a different material than a light weight viscoelastic material. For example, the insert may be formed of a higher density material in an effort to adjust the center of gravity upward and increase the IZZ.
Similarly to the previously discussed embodiments, the insert 30 preferably is coupled to the club head 4 via a protrusion 19. In the illustrated embodiment, the protrusion 19 extends rearward from the body 10 near the top 12 of the club head 4, and the entire front surface 11 of the club head 4 is formed of a metallic material. Metallic mass is removed from the rearward side of the top 12 behind the front surface 11. Protrusion 19 provides an internal mounting surface for insert 30. Additionally, part of the internal mounting surface may be provided by a back surface of the face portion and insert 30 is disposed adjacent to the back surface of the face portion.
The protrusion 19 can be positioned at any desired location towards the top 12 of the club head 4. The insert 30 is formed of a material, such as nylon, having a high strength-to-weight ratio and a high impact strength-to-weight ratio. These properties ensure that the insert 30 provides a solid feel to the club head 4 while achieving the benefits, discussed above, of removing metallic material from the top line 12.
In this aspect of the invention, the insert material preferably has the following properties at 50% relative humidity and 73° F.; tensile strength of 15 kpsi to 20 kpsi, 17.5 kpsi being preferred; flexural modulus of 650 kpsi to 750 kpsi, 600 kpsi being preferred; notched impact strength of 3 ftlb/in to 4 ftlb/in, 3.5 ftlb/in being preferred; and specific gravity of 1.25 to 2, 1.4 being preferred. These properties and measurement methods are discussed in ASTM D 638, ASTM D 790, ASTM D 256, and ASTM D 792, respectively, which are incorporated herein by reference. One preferred material for the insert 30 of this embodiment is a 33% glass reinforced nylon 66. An insert may include a nylon such as the nylon material sold under the name ZYTEL 74G33L NC 010 by E. I. du Pont de Nemours and Company (Wilmington, Del.). This product meets the preferred physical properties and allows the club designer to provide a top line 12 with a surface finish similar to that of an all steel club head, which may be beneficial to some golfers. More or less glass reinforcement may be used. In particular, while 25 percent to 50 percent is a preferred range for glass (including fiberglass) reinforcement in the nylon material of the insert 30, other amounts may be used. In addition, other reinforcing materials other than glass may also be used.
The club head 4 of
A third insert 48 may also be included with the club head 4. This third insert 48 preferably is coupled to the back 14 of the club head 4, opposite the front surface 11. The insert 48 preferably is formed of a viscoelastic material, and thus it damps unwanted vibrations via free-layer damping. The insert 48 may be coupled to the club head 4 in any known manner, such as via an adhesive. The insert 48, as well as the other inserts described herein, may also inherently possess adhesive properties such that it may couple directly to the club head without the need of a separate adhesive material.
In addition to removing mass from the central portion of the top line 12, additional material, and therefore mass, may be removed from heel and toe portions of the top line 12.
These toe and heel top line recesses work in conjunction with the central top line recess to remove unneeded club head mass from the upper portion of the club head, which may be repositioned as added mass or weight members in other, more beneficial locations of the club head while keeping the overall club head mass and weight constant. For example, mass may be added to heel and toe portions of the sole, such as by including additional material forming the club head body 10 or by incorporating weight inserts. This beneficially further lowers the club head center of gravity, making the resulting golf club easier to use. Furthermore, repositioning of the “saved” mass and weight to toe and heel portions of the club head further increase the club head MOI, making the club head more stable and forgiving, also increasing the playability of the resulting golf club.
In addition to the first rear insert 52, the club head 6 further includes a second rear insert 54. This insert 54 is positioned atop the first insert 52, and includes a notch at its lower end to contact and overlap the first insert 52. As shown in
In another embodiment of the invention as seen in
Any of the inserts discussed herein including, but not limited to, inserts 30, 35, 37, 50, 60, 65, 67, and 80 may be retained within the respective recesses in known manner, such as through use of an adhesive or epoxy. Alternatively, the inserts of the invention may be molded in place, known as “co-molding.” To ensure a smooth top line surface along the entire length of the top line, the top line, with the inserts in place, may be polished. This may be performed, for example, through wet sanding or grinding, which facilitates simultaneous removal of both metallic and polymer/nylon materials. Preferably, the toe and heel recesses are spaced from the central recess by portions of the club head body. This helps ensure that structural integrity of the club head is retained. The insert(s) may also be held in place by utilizing the protrusion configurations generally shown in
As previously described, the golf club head of the present invention has a moment of inertia IZZ about an axis that passes through the center of gravity and is parallel to the z-axis (as shown in
In addition, the moment of inertia IZZ for a club head of the present invention may be related to the vertical center of gravity (CGZ) by the following equation:
I
ZZ
≧CG
Z×170
where IZZ is in g·cm2 and CGZ is measured in millimeters (mm) in the z-direction.
In one embodiment, the club head satisfies the following relationship between the specific gravity of a low density, light weight top line insert, the moment of inertia IZZ, and the center of gravity CGZ:
I
ZZ
≧CG
Z
×SG×130
where specific gravity of the insert is SG, IZZ is greater than 2500 and is in g·cm2, and CGZ is measured in millimeters (mm) in the z-direction.
In another embodiment, the club head satisfies the following relationship between the specific gravity of a high density, heavy weight top line insert, the moment of inertia IZZ, and the center of gravity CGZ:
I
ZZ
≧CG
Z
×SG×17
where specific gravity of the insert is SG, IZZ is greater than 2500 and is in g·cm2, and CGZ is measured in millimeters (mm) in the z-direction.
A set of club heads including at least one club head with a low density (light weight) and at least one club head with a high density (heavy weight) insert will preferably have clubs in the set that meet the relationship of all three equations.
As discussed above,
Aspects of the invention include the insight that club head mass distribution can be improved by extending a dimension of insert 30. In some embodiments, insert 30 extends across a top line of a club head in a heel-ward direction and through a hosel area. Additionally, a recess in hosel 17 aids bending while allowing hosel material to gently redistribute during bending without straining the material. Insert 30 provides a smooth finish on the hosel side surface of the club head body so that the recess does not interfere with aerodynamics or trap dirt from the environment. Bendability in club heads is discussed in U.S. Pat. No. 6,186,903 to Beebe and U.S. Pub. 2012/0115632 to Cackett, the contents of each of which is incorporated by reference.
In some embodiments as depicted for example in
Insert 30 may be translucent or clear. Providing a translucent or clear insert may provide useful benefits by revealing a portion of material that is otherwise covered by insert 30. For example, with reference to
Insert 30 may be interchangeable by a golfer. Insert 30 can be held in place by a press-fit, or an adhesive that is easy to peel off, or by other means, such that a golfer can remove one and replace it. This provides a benefit as a metal component of a club head may have very long longevity while insert 30 may weather or face in the sun after a period.
Insert 30 may be moveable (i.e., repositionable) or removable (i.e., interchangeable) also to provide a benefit in club fitting. When a club head is prepared for a golfer according to the golfer's specifications, it is clamped in a vise in a fitting station machine, a cheater bar is slipped over the shaft (or a shop shaft used for bending), and the hosel is bent until the final shape is obtained. In some embodiments, it may be preferable for the vise to only contact the material (e.g., metal) of the club head body. In such a case, it may be desirable to remove the insert for fitting or even to not have yet added an insert. In certain embodiments, for example where a club head has a delicate finish, it may be desirable to place an oversized dummy insert into the recess and clamp the head into the vise such that the jaws of the vise grip the dummy insert and do not make contact with the club head body. If the insert is interchangeable, this benefit can be obtained if the club is refit in a fitting station machine even after being sold to the customer, used, and brought back to the fitting station.
In certain embodiments, a club head comes with a set of interchangeable inserts and a golfer can use the insert of his preference. This is beneficial due to the properties of insert 30. In all embodiments, insert 30 may provide good vibration-dampening benefits to a club head. Where a club head comes with a plurality of insert 30, each of the plurality may have a different elastic modulus. A golfer can chose the insert 30 that provides the requisite amount of vibration-dampening and insert it into the club head (e.g., to be mounted there by press-fit, golfer-applied adhesive, or other means).
Insert 30 may be co-molded with the club head. Co-molding may refer to the use of two separate molds on a club head or may be taken to include a one or more applications of a molding process with multiple materials or components, combining the materials or components to provide a unitary piece. See, e.g., U.S. Pat. No. 7,922,604.
A mounting surface of the club head for contact with insert 30 may include micro-cavities for good adhesion. A material of insert 30 may extend into the micro-cavities, particularly when co-molded.
As shown in
In some embodiments, such as in
As shown in
As shown in
A vertical dimension of insert 30 can be greater than a vertical dimension of topline 12 such that if they are close to being aligned to one another across the top of club head 103, then insert 30 extends beneath top line 12 and into the cavity when the club is at address (see also
The use of the terms “a” and “an” and “the” and similar references in the context of describing the invention are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein.
As used herein, directional references such as rear, front, lower, etc. are made with respect to the club head when grounded at the address position. See, for example,
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, 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 description and 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 any 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.
While the preferred embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not of limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus the present invention should not be limited by the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. Furthermore, while certain advantages of the invention have been described herein, it is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
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.
This application is a continuation of U.S. patent application Ser. No. 13/772,821, filed Feb. 21, 2013, which is a continuation-in-part of U.S. patent application Ser. No. 13/336,630, filed Dec. 23, 2011, now U.S. Pat. No. 8,393,976, which is a continuation of U.S. patent application Ser. No. 12/362,666, filed Jan. 30, 2009, now U.S. Pat. No. 8,088,022, which is a continuation-in-part of U.S. patent application Ser. No. 11/896,237, filed Aug. 30, 2007, now U.S. Pat. No. 7,938,737, which is a continuation-in-part of U.S. patent application Ser. No. 11/266,172, filed Nov. 4, 2005, now U.S. Pat. No. 7,524,250, which is a continuation-in-part of U.S. patent application Ser. No. 10/843,622, filed May 12, 2004, now U.S. Pat. No. 7,481,718, the contents of each of which are incorporated herein by reference in their entirety. This application is also a continuation of U.S. patent application Ser. No. 13/904,585, filed May 29, 2013, which is a continuation of U.S. patent application Ser. No. 11/266,180, filed Nov. 4, 2005, now U.S. Pat. No. 8,480,506, which is a continuation-in-part of U.S. patent application Ser. No. 10/843,622, filed May 12, 2004, now U.S. Pat. No. 7,481,718, the contents of each of which are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14584515 | Dec 2014 | US |
| Child | 15144152 | US | |
| Parent | 13904585 | May 2013 | US |
| Child | 14584515 | US | |
| Parent | 11266180 | Nov 2005 | US |
| Child | 13904585 | US | |
| Parent | 13772821 | Feb 2013 | US |
| Child | 14584515 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10843622 | May 2004 | US |
| Child | 11266180 | US | |
| Parent | 13336630 | Dec 2011 | US |
| Child | 13772821 | US | |
| Parent | 12362666 | Jan 2009 | US |
| Child | 13336630 | US | |
| Parent | 11896237 | Aug 2007 | US |
| Child | 12362666 | US | |
| Parent | 11266172 | Nov 2005 | US |
| Child | 11896237 | US | |
| Parent | 10843622 | May 2004 | US |
| Child | 11266172 | US |
