Abstract: A golf club head including a striking face, a periphery portion surrounding and extending rearwards from the striking face, a damping element including a front surface and a rear surface, the rear surface of the damping element opposite the front surface of the damping element, wherein the striking face comprises a first portion having a substantially constant thickness, wherein the front surface of the damping element comprises a geometric center, wherein the golf club head includes additional damping structures and materials to achieve desired acoustic characteristics.

Abstract: An iron type golf club head, including a body including a striking face, a topline located at a top of the striking face, a leading edge located at a bottom of the striking face, a body sole surface extending rearward from the leading edge, a hosel located at a heel side of the golf club head, a toe side opposite the heel side, a sole plate rotatably coupled to the body, wherein the sole plate comprises an adjustment member located between the body and the sole plate, wherein the adjustment member is adjustable between a maximum bounce position and a minimum bounce position.

Abstract: A golf club head according to the disclosure is a cavity-back iron type golf club head that includes a face portion, a cavity portion provided behind the face portion, and a protrusion provided on a lower part of a rear face of the face portion. The protrusion includes a first recess extending from an upper surface of the protrusion toward a sole, a second recess positioned closer to a toe than the first recess is and extending from the upper surface of the protrusion toward the sole, and a thick portion provided between the first and second recesses in a toe-heel direction. The first and second recesses each has a substantially trapezoidal shape in a cross-sectional view taken along a plane that is parallel to a front face of the face portion and passes through a deepest part of each of the first and second recesses.

Abstract: A golf club head with plate-like, heel and toe side internal stiffeners is disclosed herein. Each stiffener has a planar portion extending approximately parallel with a portion of the striking face, and is entirely disposed within an interior cavity of the golf club head. The heel side stiffener is connected to top, sole, and heel walls of the club head, with a toe-side edge unconnected to any other portion of the head, and the toe side stiffener is connected to the top, sole, and toe walls of the club head, with a heel-side edge unconnected to any other portion of the head. The toe and heel side edges may have large concavities that distribute mass away from the geometric face center and toward the heel and toe sides of the golf club head.

Abstract: Described herein is a hollow body iron-type golf club head having a sole and ballast configured to relieve stress within a forward portion of the sole. In a first configuration, the golf club head comprises a ballast undercut for relieving stress. In other configurations, the ballast undercut is combined with additional stress relief features, such as a cascading sole near the face sole juncture, for further reductions to face thickness.

Abstract: A golf club head with an improved sole profile is disclosed herein. More specifically, the present invention discloses various types of irons, including wedges, having a toe portion, a heel portion, and a center portion therebetween, in which a camber radius of a sole as measured from a front to a back of the golf club head changes moving from the toe portion through the center portion to the heel portion. In addition, a bounce angle of the golf club head also changes moving from the toe portion through the center portion to the heel portion. The resulting golf club head improves performance, as this new sole profile allows specific portions of the sole to have a profile that meets the needs at that location.

Abstract: Described herein is a golf club head comprising a composite material, the golf club head further comprising: a front end having a bottom rail, a top rail, and a strikeface, the strikeface including a striking surface, a back surface, and a reinforcement element extending from the back surface of the strikeface; a rear end opposite the front end; a heel portion; a toe portion opposite the heel potion; a sole coupled to the front end along the bottom rail at a sole transition region, the sole extending toward the rear end of the golf club head and including a sole thickness, a first weight member and a second weight member, and a perimeter wall extending from the front end near the heel portion to the front end near the toe portion along the rear end of the golf club head, wherein the perimeter wall decreases in height from the front end toward the rear end of the golf club head.

Abstract: A golf club head including a striking face including a front surface configured to strike a golf ball and a rear surface opposite the front surface, a damping element abutting the rear surface of the striking face, wherein the damping element comprises a binder and a filler, wherein the filler has a density less than or equal to 2 g/cc and the binder has a density greater than or equal to 3 g/cc and less than or equal to 12 g/cc, wherein the filler is substantially evenly distributed throughout the binder, wherein the filler comprises a plurality of particles, wherein the particles of the filler are less than 5.0 mm in diameter, and wherein the damping element comprises an average thickness, wherein the average thickness of the damping element is greater than or equal to 5 ?m and less than or equal to 100 ?m.

Abstract: An iron-type golf club head is provided with a body having a volume less than 120 cc. The body can include a sole portion with two or more slots extending upwardly into the body through the sole portion into a cavity behind a face portion. A damper can be included in the cavity and in contact with a rear surface of the face portion. The club head can have a maximum CT proximate to the ideal striking location and a CT dropoff of no more than 110 ?s at a point located between a first and second scoreline proximate to the sole portion. The club head can also have a CG along the y-axis (CG-y) between 0.25 mm and 20 mm and a CG along a positive z-up axis (CG-z) between 12 mm and 25 mm.

Abstract: Embodiments of a golf club head with an internal lattice structure are described herein. The golf club head can be an iron or putter-type club head. The lattice structure can have varying beam thicknesses that correlate to the effective density profile of the lattice. The effective density of the lattice structure can range between 0 g/mm3 and 0.0075 g/mm3, achieving beneficial product of inertia values for irons and a forward CG location for a putters. For irons, an Ixy product of inertia can be greater than or equal to ?40 g·in2. An Ixz product of inertia can be less than or equal to ?25 g·in2, resulting in improved sidespin for high and low face impacts. The lattice structure can concentrate mass into a high-toe and a low-heel quadrant or region of the iron to achieve the product of inertia values. Other embodiments may be described and claimed.

Abstract: In general, aspects of this invention relate to blade-type iron golf clubs or golf club heads. The blade-type golf club head may comprise a body forged of a metal material. The body may include a hosel, a top surface, a sole, a heel, a toe, a ball striking surface, and a rear surface opposite the ball striking surface. The rear surface may have an upper blade portion and a lower muscle portion with the upper blade portion separated from the lower muscle portion by a blade interface. The lower muscle portion may have a muscle portion surface are that includes a heel muscle surface area measured from the ball striking centerline to the heel and a toe muscle surface area measured from the ball striking centerline to the toe. The toe muscle surface area may make up at least 60% of the muscle portion surface area. The mass distribution of the lower muscle portion moves the center of gravity of the club head closer to the face center location.

Abstract: A variable face thickness pattern is determined for a golf club head by setting a target value for a first constraint. Parametrization zones are defined and values set for a first parameter and a second parameter for each parametrization zone. Resultant first constraint values are evaluated from simulated impacts against the target first constraint value and the values are changed for the first and second parameters to result in a simulated face thickness pattern. In one aspect, the club head has a maximum coefficient of restitution at a first location of the striking face and a second coefficient of restitution that is no less than 98% of the maximum coefficient of restitution at a second location that is at least 7.5 mm from the first location. In another aspect, the club head has a moment of inertia, Izz, and a mass, mh, satisfying: Izz>mh*9.3 cm2.

Abstract: A multi-material iron-type golf club head having a shell that defines a closed internal volume, where the head is composed of at least two different materials, incorporates a variable face thickness, and achieves a high characteristic time.

Abstract: A method has acts of providing a blank of head, providing a reinforcement element, combining the blank of head and the reinforcement element, and co-forging. The blank of head is made of a material having a hardness ranging from HRB50 to HRB105 measured by Rockwell Hardness Test and being softer than HRB105 and has a recess. The reinforcement element is made of a material having a hardness ranging from HRC15 to HRC55 measured by Rockwell Hardness Test. The reinforcement element is put into the recess in the blank of head, and an inner surface of the recess and the reinforcement element are combined securely with each other completely by a welding process. The blank of head combined with the reinforcement element is put into a mold, is heated to 700° C. to 1100° C., and is applied with a co-forging process to form an eutectic bonding by thermocompression.

Abstract: Described herein is a golf club head comprising a deflection feature to increased ball speed and launch distance, while producing desirable acoustics and optimized mass distribution. The deflection feature can include any one of or any combination of an insert comprising a gap, an insert comprising voids, a thin uniform sole, a cutout in the top rail, optimized face material, a thin sole, a reinforcement device, or a multi material weight. The rear cavity insert comprises voids within the body of the insert providing a change of insert density. The faceplate comprises a reinforcement element allowing the faceplate thickness to be reduced while simultaneously reducing faceplate stress.

Abstract: A club head with a variable face thickness includes a body having a toe, heel, sole, and top portion. The loft angle LA and the club head mass mh satisfy mh=2.1 g/degree*LA+a, where 190 g<a<210 g, and the club head has a blade length less than 80 mm. A striking face of the club head has a face center, and defines a face plane. A virtual center plane extends vertically through the face center perpendicularly to the face plane. A center of gravity of the club head is located not more than 2.0 mm from the virtual center plane, and a moment of inertia about a vertical axis extending through the center of gravity satisfies: Izz>mh*9.3 cm2. In one aspect, a face insert including the striking face has a mass mf such that mf/mh is less than or equal to 0.22.

Abstract: In general, aspects of this invention relate to blade-type iron golf clubs or golf club heads. The blade-type golf club head may comprise a body forged of a metal material. The body may include a hosel, a top surface, a sole, a heel, a toe, a ball striking surface, and a rear surface opposite the ball striking surface. The rear surface may have an upper blade portion and a lower muscle portion with the upper blade portion separated from the lower muscle portion by a blade interface. The lower muscle portion may have a muscle portion surface are that includes a heel muscle surface area measured from the ball striking centerline to the heel and a toe muscle surface area measured from the ball striking centerline to the toe. The toe muscle surface area may make up at least 60% of the muscle portion surface area. The mass distribution of the lower muscle portion moves the center of gravity of the club head closer to the face center location.

Abstract: A golf club head includes a main body having a topline and an opposing sole. The main body includes a striking face extending between the topline and sole, and a rear face in opposed relation to the striking face. A sole body is proximate the rear face and extends at least partially along the sole. A peripheral flange extends at least partially about the rear face and is of a flange height, HF, relative to the rear face. A truss protrudes from the rear face and includes a at least a first truss arm which is of a first truss arm height, HT1, relative to the rear face, wherein the difference between HF and HT1 is less than about 0.25 mm.

Abstract: A golf club head includes a body having a face plate having a strike surface and an opposing interior surface, a rear end, and a sole connecting the faceplate with the rear end. The face plate, the rear end, and the sole partially define a cavity. An insert is positioned within the cavity, the insert presenting an insert surface facing the interior surface of the face plate and spaced therefrom.

Abstract: A head includes a head body including a sole and a face plate fixed to the head body. The face plate includes a plate front surface that forms a part of a hitting face, a plate rear surface, and a plate side surface. The head body includes an opening at which the face plate is disposed, and a back support portion that supports the face plate from a back side. The back support portion includes a back receiving surface forming an abutting region by abutting on an outer peripheral edge portion of the place rear surface, and a rear surface that is a surface opposite to the back receiving surface. A face-peripheral-side end of the rear surface is located on a face peripheral side relative to a face-center-side end of the abutting region.

Abstract: A multi-material iron-type golf club head having a shell that defines a closed internal volume, where the head is composed of at least two different materials, incorporates a variable face thickness, and achieves a high characteristic time.

Abstract: A golf club head including a club head perimeter comprising a toe portion, a heel portion, a topline, and a sole portion; a striking face; and a cantilevered face support secured to the interior surface of the sole portion; wherein the cantilevered face support tab is in contact with but not secured to the rear surface of the striking face; wherein the striking face includes a centrally located first portion having a first portion thickness, a second portion having a second thickness and located heelward of the first portion, and a third portion having a third thickness and located toeward of the first portion; wherein the first thickness is greater than the second thickness, wherein the first thickness is greater than the third thickness; and wherein the cantilevered face support tab is in contact with the first portion.

Abstract: A ball striking device, such as an iron-type golf club head, includes a face having a ball striking surface and a rear surface, and a body connected to the face. The body has a sole member and a rear cavity defined at least partially by the sole member and the rear surface of the face. The body has an elongated, recessed channel extending within the cavity along a juncture line between the rear surface of the face and the sole member. Additionally, the head is formed in part by a face member having a first leg forming at least a major portion of the face and a second leg extending rearwardly from a bottom end of the first leg and forming at least a portion of the sole member. The head may further be formed by a body member connected to the face member.

Abstract: A golf club head comprises a loft angle no less than 18°, a striking face, a sole portion, and a top portion having an exterior surface. In an imaginary vertical plane spaced from a face center by no more than 10 mm and perpendicular to an imaginary striking face plane, an imaginary line segment has a length of 25 mm, a first endpoint located in the imaginary striking face plane, a second endpoint located above the exterior surface, and forms an angle ? with the striking face plane between 55° and 65°. The line segment is tangent to the exterior surface at a first point. A second point is located on the imaginary line segment and spaced from the first point by no less than 1 mm. The second point is spaced from the exterior surface by a gap distance that is no greater than 0.15 mm.

Abstract: Some embodiments include a golf club head with an insert. Other embodiments for related golf club heads and methods are also disclosed.

Abstract: Embodiments of golf club heads and methods to manufacture golf club heads are generally described herein. In one example, a golf club head may include a body portion with a toe portion, a heel portion, a top portion, a sole portion, a back portion, and a front portion having a face portion with a face portion thickness extending between a front surface and a back surface. The body portion may be associated with a body portion volume. The golf club head may also include an interior cavity. The interior cavity may include an elastic polymer material. Other examples and embodiments may be described and claimed.

Abstract: Embodiments of a golf club head having a body comprising a first material and a strike face comprising a second material, wherein the density of the first material is greater than the density of the second material, and the ratio of the density of the first material to the density of the second material is greater than or equal to approximately 1.7 are described herein.

Abstract: A golf club head with a face stress-reduction structure disposed proximate a rear surface of a striking face is disclosed herein. In particular, the structure is an adjustable tension cable assembly extending from an upper portion of the golf club head, preferably a return section, to a lower portion of the golf club head, preferably a sole portion, approximately parallel with the rear surface of the striking face. The cable assembly comprises a cable portion, a hollow sleeve, and a screw plug.

Abstract: An iron-type golf club head having a club face provide with a plurality of grooves extending in the toe-heel direction, satisfies the following conditions (1) the loft angle of the club head is not more than 41 degrees, (2) the thickness of the club head is not more than 23 mm, (3) the height of the club face measured along the club face at the position of the most toe-side end of the grooves is not less than 53 mm, (4) in a standard state of the club head set on a horizontal plane at the lie angle and loft angle specified for the club head, the ratio M/Sh (g sq·cm/mm) of a moment M of inertia (g sq·cm) around a first axis passing through a sweet spot in parallel with the club face and perpendicularly to the grooves, and a sweet spot height Sh (mm) which is the vertical height from the horizontal plane to the sweet spot is not less than 152.

Abstract: In general, aspects of this invention relate to blade-type iron golf clubs or golf club heads. The blade-type golf club head may comprise a body forged of a metal material. The body may include a hosel, a top surface, a sole, a heel, a toe, a ball striking surface, and a rear surface opposite the ball striking surface. The rear surface may have an upper blade portion and a lower muscle portion with the upper blade portion separated from the lower muscle portion by a blade interface. An average height of the lower muscle portion from the ball striking centerline to the toe-side boundary line may be approximately twice an average height of the lower muscle portion from the heel-side boundary line to the ball striking centerline. The mass distribution of the lower muscle portion moves the center of gravity of the club head closer to the face center location.

Abstract: This disclosure describes golf club heads with optimized aerodynamics, in which a highly-lifted trailing edge minimizes drag, and in which a protruding element optimizes a location of a club head center of gravity. Features of the disclosure reduce drag forces on a club head during a golf swing and consequently reduce the work required to move the club head through the air. Thus, the club heads allow golfers to achieve faster golf swing velocities and increase golf shot distances.

Abstract: Disclosed herein is an iron-type golf club head comprising a body comprising a heel portion, a sole portion, a toe portion, and a topline portion. The topline portion has a mass per unit length of between 0.09 g/mm and 0.40 g/mm. The golf club head also comprises a strike plate coupled to the body at a front portion of the golf club head and a cavity defined between the topline portion, the sole portion, and the strike plate. The golf club head further comprises a bridge bar at a rear portion of the golf club head. The bridge bar spans the cavity, is spaced apart from the strike plate, and is rigidly fixed to and extends uprightly between the sole portion and the topline portion. The bridge bar has a mass per unit length of between 0.09 g/mm and 0.40 g/mm.

Abstract: An iron golf club head comprises a clubface with score lines, a top, a sole, a hosel with a shaft inserting hole. In a standard state of the head set on a horizontal plane such that the score lines become horizontal and the axis of the club shaft inserting hole lies within a vertical plane, the head satisfies the following condition (1) in the cross section of the head taken orthogonally to the vertical plane at any position in the toe-heel direction between the heel-side most end of the score lines and the position at which the clubface height becomes maximum: (1) the horizontal distance A from the lower edge of the clubface to a backmost end of the head on the sole-side is not more than the horizontal distance B from the lower edge of the club face to a backmost end of the head on the top-side. The depth of the center of gravity is 5.5 mm or more.

Abstract: Some embodiments include a golf club head with an insert. Other embodiments for related golf club heads and methods are also disclosed.

Abstract: The present invention is direct to a set of golf clubs comprising long irons, mid-irons and short irons. The invention contemplates the use of titanium or steel for the main body portion and significant tungsten weight members coupled to at least the toe and a heel weight member coupled in a hosel cavity.

Abstract: A golf club head including a striking face, a periphery portion surrounding and extending rearwards from the striking face, wherein the striking face comprises a front surface configured to strike a golf ball and a rear surface opposite the front surface, wherein the rear surface of the striking face comprises a supported region, a support arm spaced from the rear surface of the striking face, the support arm extending from the periphery portion towards the supported region, a deformable element residing between the support arm and the rear surface of the striking face, and wherein the deformable element comprises a front surface in contact with the rear surface of the striking face and a rear surface in contact with the support arm.

Abstract: A golf club head having elevated internal weighting that improves ball speed, reduces backspin, and increases launch angle is disclosed herein. In particular, the golf club head comprises a hollow body with a face, sole, and elevated weight bar, which is disposed inside the body and is fixed to heel and toe sides of the body, preferably with mechanical fasteners such as screws or bolts. The weight bar bridges a central portion of the sole, and a central section of the weight bar, which preferably comprises at least 50% of the overall mass of the weight bar, extends towards the face without actually making contact with the face. The sole also includes at least one slot extending perpendicular to the face and underneath the central section of the weight bar, the slot having a front-to-back length that is greater than a maximum front-to-back length of the weight bar.

Abstract: In general, aspects of this invention relate to blade-type iron golf clubs or golf club heads. The blade-type golf club head may comprise a body forged of a metal material. The body may include a hosel, a top surface, a sole, a heel, a toe, a ball striking surface, and a rear surface opposite the ball striking surface. The rear surface may have an upper blade portion and a lower muscle portion with the upper blade portion separated from the lower muscle portion by a blade interface. An average height of the lower muscle portion from the ball striking centerline to the toe-side boundary line may be approximately twice an average height of the lower muscle portion from the heel-side boundary line to the ball striking centerline. The mass distribution of the lower muscle portion moves the center of gravity of the club head closer to the face center location.

Abstract: A golf club head having elevated internal weighting that improves ball speed, reduces backspin, and increases launch angle is disclosed herein. In particular, the golf club head comprises a hollow body with a face, sole, and elevated weight bar, which is disposed inside the body and is fixed to heel and toe sides of the body, preferably with mechanical fasteners such as screws or bolts. The weight bar bridges a central portion of the sole, and a central section of the weight bar, which preferably comprises at least 50% of the overall mass of the weight bar, extends towards the face without actually making contact with the face. The sole also includes at least one slot extending perpendicular to the face and underneath the central section of the weight bar, the slot having a front-to-back length that is greater than a maximum front-to-back length of the weight bar.

Abstract: A ball striking device, such as an iron-type golf club head, includes a face having a ball striking surface and a rear surface, and a body connected to the face. The body has a sole member and a rear cavity defined at least partially by the sole member and the rear surface of the face. The body has an elongated, recessed channel extending within the cavity along a juncture line between the rear surface of the face and the sole member. Additionally, the head is formed in part by a face member having a first leg forming at least a major portion of the face and a second leg extending rearwardly from a bottom end of the first leg and forming at least a portion of the sole member. The head may further be formed by a body member connected to the face member.

Abstract: In general, aspects of this invention relate to blade-type iron golf clubs or golf club heads. The blade-type golf club head may comprise a body forged of a metal material. The body may include a hosel, a top surface, a sole, a heel, a toe, a ball striking surface, and a rear surface opposite the ball striking surface. The rear surface may have an upper blade portion and a lower muscle portion with the upper blade portion separated from the lower muscle portion by a blade interface. An average height of the lower muscle portion from the ball striking centerline to the toe-side boundary line may be approximately twice an average height of the lower muscle portion from the heel-side boundary line to the ball striking centerline. The mass distribution of the lower muscle portion moves the center of gravity of the club head closer to the face center location.

Abstract: Provided is an iron type golf club head having an undercut cavity. The iron type golf club head comprises a face portion (2) for hitting a ball; a peripheral edge (2e) of the face portion (2) is provided with a flange portion (7) protruding backward of the head; a rear surface (5) of the face portion (2) is provided with a cavity (C) surrounded by the flange portion (7). The flange portion (7) includes a first flange part (8). The first flange part (8) is provided in its inner surface (8i) side facing to the cavity (C) with a first concave part (10) dented toward the outside of the head so as to form an undercut cavity (c2) extending along the peripheral edge (2e). The cross-section of the first concave part (10) comprises a front wall surface (11) positioned frontward of the head, a rear wall surface (12) positioned backward of the head, and a bottom surface (13) smoothly connecting therebetween, and the cross-section is tapered toward the bottom surface (13).

Abstract: The invention relates to golf club heads with improved mass distribution provided by novel cellular features. Because a club head can have very low mass density in certain parts, the club head can have much more mass in other parts, while keeping the overall club head mass equal to the mass of prior art club heads. A club head can be provided with optimized MOI and CG. The novel cellular structures of invention provide extensible functionality in the form of pockets, recesses, and windows and provide materials with excellent strength and restitution properties.

Abstract: A wedge type golf club head is disclosed herein where the wedge type golf club head has enhanced performance characteristics such as improved backspin, ball speed, and launch angle. More specifically, the present invention relates to a wedge type golf club head having an adjustable center of gravity, where the center of gravity may be adjusted based on different backing profiles that comprises at least one hollow chamber. The wedge type golf club head disclosed above may also have a thickened topline, wherein the thickness of the topline progressively changes as a function of the loft angle of the wedge type golf club head.

Abstract: A golf club head having a center of gravity located at a point close to the face and the sole is disclosed herein. In particular, the golf club head comprises a hollow body including a weight lip and face component, and the weight lip extends from the sole inside the body towards the face component without making contact with the face component. The golf club head is preferably an iron-type golf club head. In other embodiments, the golf club head, which may be an iron-type golf club head, comprises a weight bar disposed within the hollow body proximate the face component, and the weight bar bridges at least a portion of the sole. The weight bar may be movable within the hollow body to allow for center of gravity adjustment.

Abstract: A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball; a channel extending across a portion of the sole, wherein the channel is recessed from adjacent surfaces of the sole; a void defined on the sole of the body and a cover defining a top of the void; and a first external rib and a second external rib wherein each external rib is connected to the cover and extends downward from the cover, such that the external ribs are positioned within the void. The channel has a width and a depth, wherein the channel comprises a center portion, a heel portion, and a toe portion, and wherein at least one or both of the width and the depth of the channel is greater at the heel portion and the toe portion than at the center portion.

Abstract: A golf club head including a strikeplate including strikeplate stiffness, a strikeface, and backface opposite the strikeface. The head also includes a modulation mechanism at the backface, a plurality of frequency modulators, and a plurality of anti-stiffening features interspersed between the plurality of frequency modulators. The plurality of frequency modulators reduces an oscillation frequency of the strikeplate upon impact with a golf ball. The plurality of anti-stiffening features permit flexing of the strikeplate between the plurality of frequency modulators.

Abstract: Embodiments of golf clubs head sets with varying characteristics are disclosed herein. Other examples and related methods are also generally described herein.

Abstract: A golf club includes a golf club head having a body, a ball-striking face member and one or more mass members. The body extends from a shaft-attachment structure. The ball-striking face member is located on a front surface of the body. The body is configured to releasably accommodate a first mass member in a first region on its back surface and a second mass member in a second region on its back surface. At least one of the first and second mass members may be releasably attached to the back surface. The ball-striking face member may have an average density that is less than the average density of the body. The mass members may have an average density that is more than the average density of the ball-striking face member and/or of the body. The mass distribution of the club head may be customized via the selection and attachment of a particular mass member. The golf club head may be an iron-type golf club head.

Abstract: A golf club head is provided having a club body having a front portion, a rear portion, a toe portion, and a heel portion. The club head also having a central portion connected with the front portion. A frame is connected with the central portion configured to provide a lightweight crown portion being located above an offset plane.