Twist Putter Face

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.

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

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. 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.

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:

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

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.

shows a perspective view of an embodiment of the present invention, in a right-handed (RH) golf putter.shows a top view of a putter club headof the golf putterof.shows a toe side view of the putter club headof the embodiment of.shows a front view of the putter club headof the embodiment of.shows a bottom view of the putter club headof the embodiment of.shows a front-top perspective view of the club headof the embodiment of.

shows a toe side section view, taken at line-(through the center) of the putter club headof the embodiment of.shows a schematic diagram of the center section of the putter club headas shown in, roll curvature definition.shows a schematic diagram of the center section shown in, roll curvature definition-with an example calculation.

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

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

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 puttermay include the putter club head, a shaftextending from the club head, and a gripfor gripping the shaft during use. The shaftextends from the club headat a hosel or neck. In some embodiments, the shaftmay extend from a hosel within the putter club headitself. In the embodiment shown, a neckextends from the putter club headand supports the shaft. The neckmay itself then be fixed to the putter club headat an adapter interface bore.

The golf putter club headthen includes a front facehaving a heel sideand a toe side. The toe sidehas a toe side vertical orientationand the heel sidehas a heel side vertical orientation. The toe side vertical orientationcorresponds to a vertical stance of the front faceof the putter club headat the toe side, and has a first anglerelative to a baseline vertical orientationof the face.

Similarly, the heel side vertical orientationcorresponds to a vertical stance of the front faceof the putter club headat the heel side, and has a second anglerelative to the baseline vertical orientationof the face.

As shown, e.g., in, the first angleis smaller than the second angle. This is meant in the sense that the first angle, considered relative to the baseline vertical orientationof the faceputter club headis typically negative, and the second anglerelative to the baseline vertical orientationis typically positive. It will further be understood that this is meant to reflect that the second angleis an angle of the club facethat generates more loft than the first angle.

This results in a spiral twist from the heel sideto the toe side, with the twist value being selected when creating the faceof the putter club head. In some embodiments, the first angleand the second angleare each approximately or less than 2 degrees. For example, the first anglemay be −2 degrees while the second anglemay be +2 degrees, resulting in a difference of 4 degrees between the toe side vertical orientationand the heel side vertical orientation. 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, an originof such a system may be defined, with the positive x-axis pointed to the heel side, 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, heightis typically the dimension in the Y direction, extending from a golf clubsoleto a topof the club. Length is typically the dimension in the Y direction, from toe sideto heel side, and width is typically the dimension in the Z direction, extending from a back to the front faceof the club.