TWIST PUTTER FACE

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent Application No. PCT/US2023/035705, filed Oct. 23, 2023, which takes priority from Provisional Patent Application No. 63/431,111, filed Dec. 8, 2022, the contents of which are incorporated by reference herein.

FIELD OF THE INVENTION

The present disclosure relates to generally sports equipment, specifically relating to golf clubs, and more specifically, golf club face configurations for putters.

BACKGROUND

It is understood in golf that changing the face configuration for putters will alter key performance parameters during use. Accordingly, this disclosure relates to the performance effects of putter face geometry.

The putting game is a precise aspect of golf and has traditionally been performed using a club with a primarily flat club face, as shown in FIGS. 1-3. Modern measurement technology and understanding affords club makers and golfers the ability to better predict the common angular mismatches that can occur as a result of the putter head's fundamental nature of motion as being circular on an inclined plane.

Confidence is a key to better performance in golf, generally and in putting, specifically. Confidence may be enhanced by reducing the uncertainty by reducing player variables. Reducing variables may be achieved by the minimization of skill dependent manipulation of the club head that require precise timing. Armed with a clearer understanding of impact dynamics along with equipment that automatically compensates for these dynamic variables, a golfer may confidently, and more successfully, perform the task of putting with a minimum of manual compensation.

There is therefore a need for a putter face which dynamically compensates the impact face angle for common accidental and intentional off-center face strikes. This dynamic alteration produces closer to optimal ball dynamics and start direction despite off-center impact.

SUMMARY

A golf putter club head is provided in which a variably curved putter face is structured to account for various dynamic variables. Accordingly, the shape of the golf putter club face improves player performance.

The present disclosure provides a golf putter, and more specifically, a putter with a novel face shape described, in some embodiments, as a 3-dimensional (3D) variable convex, curved surface, which can be geometrically defined by:

A profile curve: a two-dimensional (2D) roll curve—the exponential side profile curve.

A path curve: a three-dimensional (3D) bulge curve—the intersection of the 2D bulge curve projection from the top plan view and the face center, 2D rocker curve.

A twist: a rotation of the 2D roll curve profile along surface sweep path (axis of twist is the instantaneous tangent vector on the 3D bulge curve path, predominantly along the x-axis. In some embodiments, the preferred twist amount is effectively 1.0 deg. lower loft toe side, and 1.0 deg. higher loft heel side.

In some embodiments, the benefit of this present invention is based on three primary assumptions: first, the putter swing is circular on an inclined plane. Second, the player prefers to observe the putter head square to the intended target line at address. Third, it is easier for the player to hold the head and face angle constant with respect to the swing path, rather than manually time an opening and closing face angle at impact.

The function of bulge, roll, and twist in the embodiments described is different from the function of bulge, roll, and twist in a driver or wood club. Specifically, the prior art of bulge, roll, and twisted face shape of a driver or wood club is intended to address the excessive gear effect spin imparted to the ball at off-center higher speed impacts. In short, by effectively raising the static loft such that it is higher toward the toe, and reducing the loft such that it is lower toward the heel, a wood or driver will compensate for this sub-optimal spin on off-center strikes. It is worthy of note that the present invention addressing putters is then counterintuitive, since it serves a different purpose, and it presents with an opposite direction twist (lower loft toe side and higher loft heel side) compared to the aforementioned twist of existing drivers and woods.

Traditionally, optimal launch angle for a ball leaving a putter face on normal green conditions is between 1-3 deg. This is the optimal range wherein a minimum of ball bouncing and or skidding will occur. For the purpose of embodiments described herein, the dynamic loft (or loft the putter face presents at the moment of ball impact) is near equal to the optimal launch angle. Furthermore, the dynamic loft angle will be a function of the static loft angle of the face (static angle of a putter face at the impact position) and the delivery angle of attack (AOA). A downward descending approach will be a negative AOA, whereas an upward ascending approach will be a positive AOA. The dynamic loft will be the sum of the static loft plus the AOA.

A player who approaches impact with a descending AOA will typically also present the ball with less dynamic loft. Conversely, a player who approaches impact with an ascending AOA will, typically, present higher dynamic loft. Therefore, it is of benefit for a putter to present more loft for a player with a descending impact, while preferably presenting less loft for a player with an ascending impact.

It is generally believed that an ascending, positive, AOA imparts favorable rolling dynamics to the ball. As a result, positive AOA is a common pattern found among better players. However, this ascending AOA—or hitting on the upstroke (up on the ball), while providing better roll, does introduce an increased likelihood of start line direction errors, since the higher the AOA, the more the face angle will tend to point inside the target line, due to the nature of the golf swing occurring on an inclined plane. Much of the subsequent descriptions of face angle impact dynamics described in this description will be focused on the management of this relationship between AOA and start direction.

In some embodiments, a golf putter club head is provided having a front face having a heel side and a toe side. The front face has a toe side vertical orientation corresponding to a vertical stance of the front face at the toe side, and the toe side vertical orientation has a first angle relative to a baseline vertical orientation of the face.

The front face also has a heel side vertical orientation corresponding to a vertical stance of the front face at the heel side, and the heel side vertical orientation has a second angle relative to the baseline vertical orientation of the face.

The first angle is smaller than the second angle, such that the second angle generates more loft than the first angle.

In some embodiments, the first angle is negative and the second angle is positive.

In some embodiments, the first angle and the second angle are each less than two degrees.

In some embodiments, the vertical stance of the front face at the toe side corresponds to a median slope of the front face at the toe side, and the vertical stance of the front face at the heel side corresponds to a median slope of the front face at the heel side.

In some embodiments, a center vertical orientation corresponds to a vertical stance of the front face at a location between and substantially equidistant from the toe side and the heel side and having a third angle relative to the baseline vertical orientation between the first angle and the second angle.

In some such embodiments, the center vertical orientation substantially corresponds to the baseline vertical orientation of the face.

In some embodiments having a center vertical orientation, the front face comprises a continuous twist from the toe side to the heel side, the continuous twist passing through the location of the center vertical orientation.

In some embodiments, the golf putter club head includes a loft curve forming a roll about a horizontal axis extending from the toe side to the heel side. In some such embodiments, the loft curve is continuously variable.

In some embodiments having a loft curve, the golf putter club head also includes at least one of a bulge about a vertical axis or a rocker curve about a horizontal axis extending substantially perpendicular from the front face.

In some such embodiments, the golf putter club head includes a sole defined by a front to back arcuate curvature.

In some embodiments having a continuously variable loft curve, the roll has a profile defined relative to a central tangent, and a tangent to the roll profile increases or decreases exponentially at distances farther from the central tangent.

In some such embodiments, the roll profile is divided into horizontal zones, and the central tangent is a tangent at a central zone, and wherein zones above the central tangent increase loft by subsequently adding lower order of magnitude changes, and wherein zones below the central tangent decrease loft by subsequently subtracting higher order of magnitude changes.

In some such embodiments, changes relative to the central tangent are defined by adding or subtracting terms each comprising a root number raised to an exponential power. In some such embodiments, the horizontal zones are five horizontal zones, and:

• • an upper middle zone directly above the central zone has a tangent defined by the central tangent added to the root number raised to the first power;
  • a top zone above the upper middle zone has a tangent defined by the central tangent added to the root number raised to the first power and the root number raised to the zeroth power;
  • a lower middle zone directly below the central zone has a tangent defined by the central tangent reduced by the root number raised to the second power; and
  • a bottom zone below the lower middle zone has a tangent defined by the central tangent reduced by the root number raised to the second power and further reduced by the root number raised to the third power.

In some such embodiments, the root number is approximately 1.6.

In some embodiments, in which the roll profile is divided into zones, the golf putter club head includes a hosel or neck having a central axis defining an axial direction of a shaft, and the central tangent defines an angle relative to a plane defined by extending the central axis in the direction of the horizontal axis of 1-5 degrees.

In some embodiments, the golf putter club head includes a top surface having a substantially straight topline leading edge corresponding to an instantaneous horizontal tangent to the face at a location between the toe side and the heel side. In some such embodiments, the golf putter club head includes a chamfer extending from the topline leading edge to the front face and extends from the toe side to the heel side, where a width of the chamfer is larger on the toe side than on the heel side. In some such embodiments, the chamber extends from the topline leading edge to the front face at a constant angle relative to the top surface, and the width is in a direction of the constant angle.

In some embodiments including a top surface with a substantially straight topline leading edge, the golf putter club head further includes a chamfer extending from the top surface leading edge to the front face and extending from the toe side to the heel side, where a width of the chamfer is larger between the toe side and the heel side than at ether the toe side or the heel side.

In some embodiments, the golf putter club head includes a top center mark identifying a horizontal location of a neutral segment of the face.

In some embodiments, the golf putter club head includes a top toe bias mark at an offset location where a face angle will present itself perpendicular to the target line, assuming approximately a 1-5 degree positive angle of attack, for a head tracking square to the path on a typical inclined plane of approximately 69-72 degree lie angle

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a toe side view, RH putter head, with a flat face.

FIG. 2 shows a front view, RH putter head, with a flat face: no iso-loft contour lines.

FIG. 3 shows a perspective front-toe view, RH putter head, with a flat face: no iso-loft contour lines.

FIG. 4 shows a perspective view of an embodiment of the present invention, in a right-handed (RH) golf putter.

FIG. 5 shows a top view of the putter club head of FIG. 4.

FIG. 6 shows a toe side view of the embodiment of FIG. 4.

FIG. 7 shows a front view of the embodiment of FIG. 4.

FIG. 8 shows a bottom view of the embodiment of FIG. 4.

FIG. 9 shows a front-top perspective view of the embodiment of FIG. 4.

FIG. 10 shows a toe side section view (through the center) of the embodiment of FIG. 4.

FIG. 11 shows a schematic diagram of the center section shown in FIG. 10, roll curvature definition.

FIG. 12 shows a schematic diagram of the center section shown in FIG. 10, roll curvature definition-with an example calculation.

FIG. 13 shows a top view, RH putter head, bulge curvature definition and markings.

FIG. 14 shows a front view, RH putter head, rocker, midline, and topline curvature.

FIG. 15 shows a front view of an embodiment of a RH putter head, with a roll and bulge lofted face, twist defining curves.

FIG. 16 shows a perspective front-toe view of the embodiment of FIG. 14, with a roll and bulge lofted face, twist defining curves.

FIG. 17 shows a toe side view, RH putter head, with a roll, bulge, and twisted loft face.

FIG. 18 shows a front view of the embodiment of FIG. 14, with a roll and bulge lofted face, including twist: iso-loft contour lines.

FIG. 19 shows a perspective front-toe view of the embodiment of FIG. 14, with a roll and bulge lofted face, including twist: iso-loft contour lines.

FIG. 20 shows an exaggerated view of a twisted face with respect to a non-twisted face, in the context of a right-handed putter.

FIG. 21 shows a front club face view, RH full club, with reference inclined swing plane.

FIG. 22 shows a heel side club view, RH full club, in descending, neutral, and ascending angles of attack (AOA) with reference inclined swing plane.

FIG. 23 shows a heel side club detail view, RH club, in descending, neutral, and ascending angles of attack (AOA) with reference inclined swing plane.

FIG. 24 shows a top address view, RH club with prior art typical flat constant loft face, face angle directions for descending, neutral, and ascending angles of attack (AOA) with reference inclined swing plane.

FIG. 25 shows a top address view, RH club with roll, bulge, and twisted continuously variable loft face, face angle directions for descending, neutral, and ascending angles of attack (AOA) with reference inclined swing plane.

FIG. 26 shows a front view, of an embodiment of a RH putter head, with a roll and bulge lofted face, but without twist: iso-loft contour lines.

FIG. 27 shows a perspective front-toe view of the embodiment of FIG. 26, with a roll and bulge lofted face, but without twist: iso-loft contour lines.

FIG. 28 shows a perspective view of an alternative embodiment of a putter in accordance with the current disclosure.

FIG. 29 shows the putter of FIG. 28 partially exploded.

FIG. 30 shows a perspective view of a club head of the putter of FIG. 28.

FIG. 31 shows a front view of the club head of FIG. 30.

FIG. 32 shows a toe side view of the club head of FIG. 30.

FIG. 33 shows a partially exploded perspective view of the club head of the putter of FIG. 28.

FIG. 34 shows a partially exploded toe side view of the club head of the putter of FIG. 28.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the exemplified embodiments. Accordingly, the invention expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.

This disclosure describes the best mode or modes of practicing the invention as presently contemplated. This description is not intended to be understood in a limiting sense, but provides an example of the invention presented solely for illustrative purposes by reference to the accompanying drawings to advise one of ordinary skill in the art of the advantages and construction of the invention. In the various views of the drawings, like reference characters designate like or similar parts.

FIG. 4 shows a perspective view of an embodiment of the present invention, in a right-handed (RH) golf putter 400. FIG. 5 shows a top view of a putter club head 500 of the golf putter 400 of FIG. 4. FIG. 6 shows a toe side view of the putter club head 500 of the embodiment of FIG. 4. FIG. 7 shows a front view of the putter club head 500 of the embodiment of FIG. 4. FIG. 8 shows a bottom view of the putter club head 500 of the embodiment of FIG. 4. FIG. 9 shows a front-top perspective view of the club head 500 of the embodiment of FIG. 4.

FIG. 10 shows a toe side section view, taken at line 10-10 (through the center) of the putter club head 500 of the embodiment of FIG. 4. FIG. 11 shows a schematic diagram of the center section of the putter club head 500 as shown in FIG. 10, roll curvature definition. FIG. 12 shows a schematic diagram of the center section shown in FIG. 10, roll curvature definition-with an example calculation.

FIG. 13 shows a top view, RH putter club head 500, bulge curvature definition and markings. FIG. 14 shows a front view, RH putter club head 500, rocker, midline, and topline curvature. FIG. 15 shows a front view of an embodiment of a RH putter club head 500, with a roll and bulge lofted face, twist defining curves. FIG. 16 shows a perspective front-toe view of the embodiment of FIG. 14, with a roll and bulge lofted face, twist defining curves.

FIG. 17 shows a toe side view, RH putter club head 500, with a roll, bulge, and twisted loft face. FIG. 18 shows a front view of the embodiment of FIG. 14, with a roll and bulge lofted face, including twist: iso-loft contour lines. FIG. 19 shows a perspective front-toe view of the embodiment of FIG. 14, with a roll and bulge lofted face, including twist: iso-loft contour lines.

FIG. 20 shows an exaggerated view of a twisted face with respect to a non-twisted face, in the context of a right-handed putter.

As shown, the golf putter 400 may include the putter club head 500, a shaft 410 extending from the club head, and a grip 420 for gripping the shaft during use. The shaft 410 extends from the club head 500 at a hosel or neck 430. In some embodiments, the shaft 410 may extend from a hosel within the putter club head 500 itself. In the embodiment shown, a neck 430 extends from the putter club head 500 and supports the shaft 410. The neck 430 may itself then be fixed to the putter club head 500 at an adapter interface bore 440.

The golf putter club head 500 then includes a front face 510 having a heel side 520 and a toe side 530. The toe side 530 has a toe side vertical orientation 540 and the heel side 520 has a heel side vertical orientation 550. The toe side vertical orientation 540 corresponds to a vertical stance of the front face 510 of the putter club head 500 at the toe side 530, and has a first angle 560 relative to a baseline vertical orientation 570 of the face.

Similarly, the heel side vertical orientation 550 corresponds to a vertical stance of the front face 510 of the putter club head 500 at the heel side 520, and has a second angle 580 relative to the baseline vertical orientation 570 of the face 510.

As shown, e.g., in FIG. 16, the first angle 560 is smaller than the second angle 580. This is meant in the sense that the first angle 560, considered relative to the baseline vertical orientation 570 of the face 510 putter club head 500 is typically negative, and the second angle 580 relative to the baseline vertical orientation 570 is typically positive. It will further be understood that this is meant to reflect that the second angle 580 is an angle of the club face 510 that generates more loft than the first angle 560.

This results in a spiral twist from the heel side 520 to the toe side 530, with the twist value being selected when creating the face 510 of the putter club head 500. In some embodiments, the first angle 560 and the second angle 580 are each approximately or less than 2 degrees. For example, the first angle 560 may be −2 degrees while the second angle 580 may be +2 degrees, resulting in a difference of 4 degrees between the toe side vertical orientation 540 and the heel side vertical orientation 550. In some embodiments, the difference is smaller, and may provide a 1 degree lower loft towards the toe side and a 1 degree higher loft towards the heel side.

As shown in many of the figures, a principal coordinate system can be defined to clarify these dimensions. As such, at the center of the face surface 510, an origin 590 of such a system may be defined, with the positive x-axis pointed to the heel side 520, the y-axis pointed upwards when the club is held upright, and the z-axis pointed towards a club target, such as a golf ball. In the context of these embodiments, height 620 is typically the dimension in the Y direction, extending from a golf club 500 sole 600 to a top 610 of the club. Length is typically the dimension in the Y direction, from toe side 530 to heel side 520, and width is typically the dimension in the Z direction, extending from a back to the front face 510 of the club 500.

In this context, the spiral twist may have a typical value of approximately −0.024 deg./mm of helical face twist in the positive X-axis direction for a right-handed putter head 500 such as that shown. While all embodiments shown represent right-handed (or RH) putter heads 500, it will be understood that a left-handed putter head would be a mirror image of that shown. Such a helical twist may be seen in the isolines, or contour lines 1800 most clearly shown in FIGS. 18 and 19.

The result of such a helical twist may be seen in the exaggerated illustration of FIG. 20, where 2000 illustrates the helically twisted face described herein and 2010 illustrates a similar club face presented without such a helical twist.

The vertical stance of the front face 510 at the toe side 530, corresponding to the toe side vertical orientation 540, corresponds to a median slope of the front face at the toe side. Similarly, the vertical stance of the front face 510 at the heel side 520, corresponding to the heel side vertical orientation 550, corresponds to a median slope of the front face at the heel side. Medians are used for the purpose of consistency in this description, and to clarify the orientation of different segments of the front face 510. However, it will be noted that similar calculations can be performed using means or other representative slopes.

Similarly, the golf putter club head 500 may include a center vertical orientation corresponding to a vertical stance of the front face 510 at a location between and substantially equidistant from the toe side 530 and the heel side 520. This may have a third angle relative to the baseline vertical orientation 570. The third angle would typically be between the first angle 560 and the second angle 580. In the embodiment shown, the center vertical orientation substantially corresponds to the baseline vertical orientation 570, resulting in a third angle of 0 degrees.

This would be expected where the baseline vertical orientation 570 is an overall average and where the helical twist of the face is consistent in the X direction. Accordingly, the front face 510 may comprise a continuous twist from the toe side 530 to the heel side 520, with that continuous twist passing through the location of the center vertical orientation, corresponding to the baseline vertical orientation 570. However, it may differ, or some other orientation may be used as a baseline in some embodiments.

In some embodiments, the golf putter club head 500 includes a loft curve, which forms a roll about a horizontal axis extending from the toe side 530 to the heel side. This would typically be an axis that parallels the x-axis of the coordinate system 590 defined above. The embodiment shown includes the helical twist discussed above, in combination with the loft curve, or roll, described herein.

Such a loft curve is most clearly shown in the section views of FIGS. 11 and 12. As shown, the loft curve may be continuously variable, such that different segments, or horizontal zones 1100, 1110, 1120, 1130, 1140, have different vertical orientations when considered independently. For the purposes of describing such segments, or zones, they will be described in terms of a central tangent, which may also be thought of as a median loft for the corresponding zone. However, as the zones are typically continuously variable, the loft will change over the course of each individual zone.

Accordingly, the embodiment shown is divided into five horizontal zones 1100, 1110, 1120, 1130, 1140. The roll then has a provide defined relative to an overall central tangent, which is the central tangent of the middle zone 1120. The tangent to the roll profile increases or decreases at distances farther from the central tangent. In the embodiment shown, the tangent value increases exponentially at distances farther from the central tangent.

Accordingly, zones above the central tangent increase, in the embodiment shown, by subsequently adding lower order of magnitude changes. Zones below the central tangent decrease loft by subsequently subtracting higher order of magnitude changes. This may be done by defining a root number and adding or subtracting terms each comprising a root number raised to an exponential power. A variety of root numbers may be used, such as 1.6, in order to approximate the golden ratio.

In more detail, in the embodiment shown, the horizontal zones are a total of five zones, where an upper middle zone 1110 directly above the central zone 1120 has a tangent defined by the central tangent added to the root number raised to the first power. A top zone 1100 above the upper middle zone 1110 then has a tangent defined by the central tangent added to the root number raised to the first power and the root number raised to the zeroth power. A lower middle zone 1130 directly below the central zone 1120 has a tangent defined by the central tangent reduced by the root number raised to the second power. Finally, a bottom zone 1140 below the lower middle zone 1130 has a tangent defined by the central tangent reduced by the root number raised to the second power and further reduced by the root number raised to the third power.

FIG. 12 illustrates these calculations in an embodiment where the root number is 1.6 and the central tangent has a value of 3 degrees.

In this way, each horizontal zone, in this case five zones 1100, 1110, 1120, 1130, 1140, is provided with a central tangent, and the instantaneous loft at each of those central tangents increases exponentially from top to bottom. Each of the five zones may then be provided with a defined central tangent. The central tangents may then be linked in a variety of ways, such as by applying a polynomial best fit spline 1150 to the surface of the club face 510.

When a roll defined in this manner is applied along with the helical twist described above, each of the baseline vertical orientation 570, the toe side vertical orientation 540, and the heel side vertical orientation 550 may have identical, or nearly identical, shapes, and they would then differ only in overall orientation.

As discussed above, the golf putter club head 500 has a hosel or a neck 430. The neck 430 supports the shaft 410 of the golf club 400. Accordingly, the hosel or neck 430 typically has a central axis 450 that defines an axial direction of the shaft 410. The central tangent then defines an angle relative to a plane defined by extending the central axis 450 in the direction of the horizontal axis corresponding to the x-axis. That angle may be any angle, but is typically 1-5 degrees. In the embodiment shown, the angle is 1-3 degrees.

In addition to the roll geometry discussed at length herein, the golf putter club head 500 may further comprise a bulge defined by a curve around a vertical axis in the Y direction. Such a bulge is most clearly visible in FIG. 13, where the face 510 of the club head 500 forms an arc of a large circle, with a toe end radius 1300 and a heel end radius 1310 extending towards an origin not visible in the drawings. The bulge may be consistent from end to end, or it may have define a larger arc at one end than the other. Accordingly, the toe end radius 1300 may or may not be the same as the heel end radius 1310.

Similarly, the golf putter club head 500 may be provided with a rocker curve about a horizontal axis in the Z direction. Such a rocker curve is most visible in the contour lines on the club face 510 presented in FIG. 14. Accordingly, the curve is visible in the sole rocker curve 1400, the midline rocker curve 1410, and the topline curve 1420 of the club face 510.

In some embodiments, the sole, or bottom surface 600, of the club is further provided with a front to back arcuate curvature, or other curvature.

In some embodiments, the golf putter club head 500 has a top surface 610 having a substantially straight topline leading edge 1320. The leading edge 1320 is parallel to an instantaneous horizontal tangent to the face 510 at a specific location between the toe side 530 and the heel side 520. Typically, the specific location is a straight region 1330 of the club face 510 between the toe side 530 and the heel side 520. In some embodiments, where the face 510 has a bulge, as discussed above, the straight region 1330 is excluded from the bulge curvature and is therefore a straight target surface. In other embodiments, the straight region 1330 is part of the bulge curvature, but represents a target surface, as it is substantially straight and parallel to the topline leading edge 1320.

As shown, the top surface 610 may include a top center mark 1340 identifying a horizontal location of the straight region 1330, which is typically a neutral segment of the face. Similarly, the top surface 610 may include a top toe bias mark 1350 at an offset location. Both the top center mark 1340 and the top toe bias mark 1350 are targeting marks that may be used by a golfer looking down towards the club head 500 and a ball during use. The top toe bias mark 1350 then represents an offset location where a face angle will present itself perpendicular to the target line, assuming approximately a 1-5 degree positive angle of attack for a golf club head 500 otherwise tracking square to the path a typical inclined plane of approximately 69-72 degree lie angle.

It is noted that the topline leading edge 1320 is substantially straight, but the club face 510 is not. As described throughout this application, the club face may be provided with various types of curve, including a helical twist, a roll, and a bulge. All three types of curves, as well as a rocker curve, present in the embodiment shown. Accordingly, the topline leading edge 1320 cannot blend seamlessly with the club face 510. Instead, a chamfer 1360 extends from the topline leading edge 1320 to the front face 510. Typically, the chamfer 1360 extends at a constant angle relative to the top surface, and the width of the chamfer is then in the direction of the constant angle. Such a configuration is visible, for example, in FIG. 10.

Similarly, in the embodiment shown, a width of the chamfer 1360 is larger on the toe side 530 than on the heel side 520, due to the helical twist of the face. The details of the chamfer geometry may be modified to accommodate different surface geometries of the club face 510. Accordingly, in some embodiments, where the bulge of the club face 510 is more extreme, the chamfer 1360 may extend from the toe side 530 to the heel side 520, and the width of the chamfer is larger between the toe side and the heel side than at either the toe side or the heel side itself. This may be due to a more extreme bulge exaggerating the distance of the straight region 1330 from the leading edge 1320. In such an embodiment, however, so long as a helical twist is present, the width of the chamfer 1360 at the toe side 1330 would still be larger than the width of the chamfer at the heel side 1320.

When the club head 500 is viewed as a whole, it is noted that in some embodiments, the club face 510 is formed on a front portion of the club head that is relatively thin, while a back portion may be configured for properly weighting the club head as a whole. Accordingly, the front portion may be taller than other portions of the club head 500. As such, the top surface 610 may be relatively thin and may have the topline leading edge 1320 discussed above and a separate topline trailing edge 1370.

In some embodiments, the leading edge of the sole 600 of the club head is separately provided with a chamfer 1380 in order to blunt and smooth any contact with the ground during a swing.

FIG. 21 shows a front club face 510 view, RH full club 400, with reference inclined swing plane 2100. FIG. 22 shows a heel side club view, RH full club 400, in descending 2110, neutral 2120, and ascending 2130 angles of attack (AOA) with reference inclined swing plane 2100. FIG. 23 shows a heel side club detail view, RH club 400, in descending 2110, neutral 2120, and ascending 2130 angles of attack (AOA) with reference inclined swing plane 2100.

As shown in FIGS. 21-23, the club face 510 is configured to adapt to imperfect hits with respect to different angles of attack. This is based on the tendencies of typical golfers. While the illustration assumes a typical hover height 2140 and a resulting dynamic loft 2150, the club face 510 configuration described herein allows for good results for a wide range of swings. As such, the differences between the loft angles 2160, 2170, 2180 resulting from the different angles of attack 2110, 2120, 2130 illustrated are not as extreme as they would otherwise be.

FIG. 24 shows a top address view, RH club 2400 with prior art typical flat constant loft face 2410, face angle directions 2420, 2430, 2440 for descending 2450, neutral 2460, and ascending 2470 angles of attack (AOA) with reference inclined swing plane 2480.

FIG. 25 shows a top address view, RH club 400 with roll, bulge, and twisted continuously variable loft face 510, face angle directions 2500, 2510, 2520 for descending 2110, neutral 2120, and ascending 2130 angles of attack (AOA) with reference inclined swing plane 2100. As shown, the golf balls 2530 hit tend to travel in offset, or biased paths corresponding to the indicated face angle directions 2500, 2510, 2520 illustrated. However, those paths trend parallel to each other, resulting in relatively similar outcomes, and the golf balls 2530 tend to follow a target line 2550.

This is distinct from the face angle directions 2420, 2430, 2440 and resulting paths taken by golf balls 2490 hit by the flat club face 2410 of FIG. 24, where the paths diverge dramatically relative to a target line 2550. Accordingly, with a traditional flat face 2410, a ball 2490 hit with a descending angle of attack 2450 will tend to be hit with a positive angle, resulting in a ball path outside 2560 the target line 2550. Similarly, a ball 2490 hit with an ascending angle of attack 2470 will tend to be hit with a negative angle, resulting in a ball path inside 2570 the target line. Such tendencies are reduced or eliminated with the club face 510 described herein.

As discussed above, in the embodiment shown in FIG. 25, both the top center mark 1340 and the top toe bias mark 1350 are targeting marks that may be used by a golfer looking down towards the club head 500 and a ball during use.

Accordingly, different players may pursue different angles of attacks during use. Many believe that an ascending, positive AOA imparts favorable rolling dynamics to the ball. As a result, a positive AOA is a common pattern found among better players. However, this ascending AOA, or hitting on the upstroke, while providing better roll, does introduce an increased likelihood of start line direction errors, for the reasons illustrated. Accordingly, the embodiments described herein are designed to manage the relationship between the AOA and the start direction of the ball 2530.

FIG. 26 shows a front view, of an embodiment of a RH putter head 2600, with a roll and bulge lofted face 2610, but without twist: iso-loft contour lines. FIG. 27 shows a perspective front-toe view of the embodiment of FIG. 26, with a roll and bulge lofted face 2610, but without twist: iso-loft contour lines. In such embodiments, some of the advantages described herein may be achieved, but not all.

FIG. 28 shows a perspective view of an alternative embodiment of a putter 2800 in accordance with the current disclosure. FIG. 29 shows the putter 2800 of FIG. 28 partially exploded. FIG. 30 shows a perspective view of a club head 2810 of the putter 2800 of FIG. 28. FIG. 31 shows a front view of the club head 2810 of FIG. 30. FIG. 32 shows a toe side view of the club head 2810 of FIG. 30. FIG. 33 shows a partially exploded perspective view of the club head 2810 of the putter of FIG. 28. FIG. 34 shows a partially exploded toe side view of the club head 2810 of the putter of FIG. 28.

As discussed above with respect to other embodiments, the golf putter 2800 may include the putter club head 2810, a shaft 2820 extending from the club head, and a grip for gripping the shaft during use. The shaft 2820 extends from the club head 2810 at a hosel 2830 or neck. As shown, the shaft 2820 may extend from a hosel 2830 within the putter club head 2810 itself.

The golf putter club head 2810 then includes a front face 2840 having a heel side 2850 and a toe side 2860, each of which have a corresponding vertical orientation, as discussed at length above.

In the embodiment of FIG. 28, the front face 2840 is integrated into a removable face 2870 which may then be mounted on a mounting surface 2900 of the cub. While the front face 2840 has varied vertical orientations and a varied curvature across the face, the mounting surface 2900 may be substantially planar.

In some embodiments, the removable face 2870 may be one of several interchangeable elements, such that the club head 2810 may be customized by switching the front face 2840. Accordingly, the golf putter 2800 or the putter club head 2810 may be provided as a kit or a set comprising the putter head 2810 and a variety of interchangeable removable faces 2870 each having a different front face 2840 geometry, thereby generating different behaviors in a ball struck by the club head 2810.

The front face 2840 may be generally angled relative to the mounting surface 2900. As such, the mounting surface 2900 may be provided at a fixed and controlled angle, such as perpendicular to a bottom surface 2905 of the club head, as in the embodiment shown. The front face 2840 may then be provided with a baseline orientation that is angled relative to the bottom surface 2905 by providing an removable face 2870 in the general form of a wedge. Accordingly, the removable face 2870 may be used to provide a front face 2840 having any of the various geometries discussed above.

The removable face 2870 may be mounted to the mounting surface 2900 by way of one or more fasteners 2910, such as the bolts shown. Further, the removable face 2870 and the mounting surface 2900 may be provided with locating features 2920, 2930 which firmly locate the removable face 2860 relative to the club head 2810 as shown. For example, a locating feature 2920 on the mounting surface 2900 may be a bore or cutout and the corresponding locating feature 2930 on the removable face 2870 may be corresponding protrusions sized to match the bore or cutout.

While the present invention has been described at some length and with some particularity with respect to the several described embodiments, it is not intended that it should be limited to any such particulars or embodiments or any particular embodiment, but it is to be construed with references to the appended claims so as to provide the broadest possible interpretation of such claims in view of the prior art and, therefore, to effectively encompass the intended scope of the invention. Furthermore, the foregoing describes the invention in terms of embodiments foreseen by the inventor for which an enabling description was available, notwithstanding that insubstantial modifications of the invention, not presently foreseen, may nonetheless represent equivalents thereto.