Patent Application
20210001190
Success in putting, an essential aspect of the game of golf, requires careful directional alignment and speed judgment. Known putters have an ideal impact location within which is it necessary to contact the ball during putting to accurately putt.
Hitting a golf shot heelward (at a location toward the heel on a face of the putter) or toeward (at a location toward the toe of the putter on the face of the putter) from a putter's ideal impact location on the face introduces an azimuthal component to the shot's trajectory, leading to the shot being missed left or right of the target. The azimuth angle of a putt that is hit outside of the ideal impact location can be minimized by manipulating the putter head's mass properties, but this type of manipulation usually comes at the cost of aesthetics, ball speed control, and the like.
Exemplary embodiments of the broad inventive principles described herein provide a putter-type golf club head that reduces shot dispersion (i.e., reduces the azimuth angle of a putt that is hit outside of the ideal impact location) without compromising the golf club head's feel upon impact with a golf ball or appearance.
In one or more exemplary embodiments, a putter-type golf club head, when oriented in a reference position, includes a main body, a weight insert, a center of gravity CG with a center of gravity depth CGD, a golf club head length L from a forwardmost extent of the golf club head to its rearwardmost extent, and a ratio of CGD/L no more than 0.30. The main body includes a front portion having a face defining a face plane, a rear portion extending rearwardly from the front portion, a heel, and a toe opposite the heel. The weight insert, which is denser than the main body, includes an insert CG that is located rearwardly from the face plane by a distance no greater than 1.0 cm.
In one or more exemplary embodiments, the weight insert includes a heel insert and a toe insert, which are received in a heel recess and a toe insert, respectively, of the face. The weight insert has a density and a mass such that the CG of the golf club head is close to the face plane. Additionally, the heel insert has a mass that is less than a mass of the toe insert.
According to one or more exemplary embodiments, a putter-type golf club head, when oriented in a reference position, includes a main body, a heel insert, a toe insert, and a CG. The main body includes a face defining a face plane, a main body length L, a heel, and a toe opposite the heel. The heel insert and the toe insert are respectively received in a toe recess and a heel recess.
In one or more exemplary embodiments, the toe and heel inserts each have a forward surface that is substantially coplanar with the face plane. The toe insert has a greater mass than the heel insert.
A putter-type golf club head having a CG close to its face (e.g., a golf club head with a CGD/L no more than 0.30) as disclosed herein provides numerous performance benefits. As explained in more detail below, off-center golf shots (i.e., where a golf ball is struck in a toeward or heelward direction away from the ideal impact location) have significantly reduced azimuth angles, which results in decreased shot dispersion. Additionally, providing a high density weight insert in a recess of the face allows the CG to be positioned near the face without compromising the appearance of a traditional putter, which can be important to a golfer's confidence.
In one or more embodiments, a golf club head, when oriented in a reference position, includes a CGD/L ratio of no more than 0.30 and a face having a plurality of grooves that vary in one or more of depth, width, and pitch outward from a face center. The plurality of grooves may vary from the face center towards the heel and toe. In one or more embodiments, each of the plurality of grooves is curvilinear. Additionally, or alternatively, the plurality of grooves may vary from the face center towards one or both of a topline and a sole.
Advantageously, shots hit with a putter having a face with groove-to-groove variation such that groove depth decreases laterally away from the face center have more consistent ball speeds on off-center shots than shots hit with uniform grooves or no grooves. Similarly, shots hit with a putter having a face with groove-to-groove variation such that groove density decreases away from the face center have more consistent ball speeds on off-center shots. Groove-to-groove variation from the face center towards one of the topline or the sole results in ball speed normalization on putts hit high or low on the face.
In one or more embodiments, a golf club head includes a CGD/L ratio of no more than 0.30 and a face having a plurality of grooves with groove profile that is designed to match mass properties of the golf club head. For example, in one embodiment, the pitch (i.e., groove-to-groove spacing) and the depth of the plurality of grooves is varied so as to be optimized to the golf club head's moment of inertia (MOI) about a vertical axis through the head's center of gravity.
Aspects of the various exemplary embodiments described herein may be implemented individually or in various combinations.
These and other features and advantages of the golf club heads described herein in its various aspects and demonstrated by one or more of the various examples will be apparent after consideration of the ensuing description, the accompanying drawings, and the appended claims.
Representative examples of one or more novel and nonobvious aspects and features of a putter-type golf club head, disclosed below, need not be limiting in any manner. Furthermore, the various aspects and features described below may be used alone or in a variety of novel and nonobvious combinations and subcombinations with one another.
For all purposes herein, the term “reference position” refers to an orientation of a golf club head relative to a virtual ground plane (e.g., virtual ground plane 10 in
Shown in
The golf club head 100 has a center of gravity (CG) 102. The CG 102 has a depth CGD, which is measured along a depth axis that passes through the CG 102 and is normal to the face plane 114. Herein, a positive CGD value denotes a golf club head CG located rearward of its virtual face plane, while a negative CGD value denotes a golf club head CG located forward of its virtual face plane. The golf club head 100 includes a weight structure comprising a heel insert 132 and a toe insert 142. The heel insert 132 and the toe insert 142 are received in respective heel and toe recesses of the front portion.
The weight structure resulting from the above-described configuration effectively moves the CG 102 of the golf club 100 toward the face 112 and reduces the golf club head's CGD. As explained in more detail below, alignment of the CG with the virtual face plane minimizes the azimuth angle of a putt's trajectory on off-center strikes, so for shot dispersion purposes, it is advantageous to minimize CGD. As used herein, the term “off-center strike” means any strike in which a surface of the golf ball is not contacted by the face center (e.g., 101) described below.
Through testing, it has been determined that CGD has a significant effect on the azimuth angle of a putt's trajectory. For example,
The contour plots of
Accordingly, it is desirable to keep the CGD as small as possible within the usual design constraints for putters. An effective way to describe the limits on CGD location for a putter is by using a ratio of CGD/L, which describes the distance of the CG from the face relative to the over length L of the club in a front-to-rear direction. As such, based on the testing and modeling described above, it has been determined that a ratio of CGD/L that is no greater than 0.30 is preferable to beneficially reduce the azimuth angel of off-center hits. More preferably, the ratio of CGD/L is no greater than 0.28. According, in one or more embodiments, the ratio of CGD/L is no greater than 0.30, and more preferably, no greater than 0.28.
However, it is also desirable to have a minimum CGD for other functional aspects of a putter-type golf club head. For example, a positive CGD is necessary to introduce gear effect on putts; due to gear effect, back spin can be reduced on a high impact putt, which in turn can improve the putt's roll. Additionally, a positive CGD helps to increase MOI, which, in addition to reducing azimuth angle, reduces ball speed dispersion. With an optimized minimum CGD, a ratio of CGD/L is no less than 0.10. Preferably, the ratio of CGD/L is no less than 0.15. Accordingly, in one or more embodiments, the ratio of CGD/L is no less than 0.10, and preferably no less than 0.15.
Returning to
The alignment element 160 helps a golfer to aim by aiding in visually indicating an ideal impact location of the putter face 112.
In one or more embodiments, a blade-type putter head 200, shown in
The golf club head 200 includes rearwardly positioned weight-reducing features that help to push the CG 202 toward the face 212. For example, the golf club head 200 includes a plurality of sole recesses 225, 226, 227, that remove mass from the rear portion of the putter. To effectively reduce mass, each of the sole recesses has a maximum depth no less than 1.0 mm. Preferably, the maximum depth is no less than 2.5 mm. The blade-type putter head 200 has a main body volume (excluding the volume of any neck or hosel) no greater than 40.0 cm3.
Shown in
The golf club head 300 includes a length L no less than 75.0 mm. The golf club head 300 also includes an overall width measured form a heelward extent to a toeward extent of the golf club head 300 that is greater than L. As such, the exemplary golf club head 300 conforms to USGA dimensional requirements for a putter-type golf club head. The golf club head 300 includes a rearwardly positioned weight-reducing feature that comprises one or more of sole recesses 325, 326, 327 that help to push the CG closer to the face 312. To effectively reduce mass, each of the sole recesses has a maximum depth no less than 1.0 mm. Preferably, the maximum depth is no less than 2.5 mm. The golf club head 300 includes a main body volume no greater than 50.0 cm3. Preferably, the main body volume is no greater than 45.0 cm3.
To beneficially affect off-center hits, this style of putter head 400 includes a CG 402 having a CGD/L ratio no greater than 0.3. The CGD of golf club head 400 is preferably no greater than 17.0 mm.
The putter-type golf club head 400 includes one or more rearwardly positioned weight-reducing features. These features include an upper toe recess 423 and an upper heel recess 424. The weight reducing features may also include sole recesses 425, 426, and 427. Each of the sole recesses 425, 426, and 427 may comprise a plurality of sub-recesses as shown in
As shown in
Golf club head 500 includes rearwardly located weight reducing features including a toe-side opening 523 and heel-side opening 524 in a rear portion 520 that extends rearwardly from a front portion 510. To effectively reduce mass in a rear part of the putter, in a preferred embodiment, each of the toe-side opening 523 and heel-side opening 524 have a maximum front to rear dimension that is at least 10.0 mm greater than a maximum heel to toe dimension. The golf club head 500 includes a volume no greater than 50.0 cm3. Preferably, the volume is about 45
Mallet-type putter heads, such as those shown in
Shown in
In blade-type putter head embodiments, the toe insert is at least 20.0 g greater than the heel insert. In mallet-type putter head embodiments, the toe insert is at least 6.0 g greater than the heel insert. These forwardly positioned inserts 632, 642 also act as weights to beneficially move the CG closer to the face and thereby reduce CGD in a way that effectively reduces the azimuth angle on off-center strikes.
A symmetric appearance of a golf club head's main body, e.g., about the vertical center plane 104 of
In order to achieve a symmetric appearance with different masses of heel and toe inserts, each of the heel and toe inserts, according to one or more embodiments, has a forward surface that is preferably parallel or substantially coplanar to a virtual face plane. Each of the forward surfaces has substantially the same area. As shown in
In another embodiment, as shown in
Importantly, to desirably reduce CGD, forwardly located weight structures, such as the heel and toe inserts described herein, have a density greater than the main body of the golf club head. The difference in densities is preferably at least 4 g/cm3. Further, to desirably reduce CGD, forwardly located weight structures, such as the heel and toe inserts described herein, have a center of gravity that is located rearwardly from the virtual face plane by a distance no more than 1.0 cm.
Further, to desirably reduce CGD, forwardly located weight structures, such as the heel and toe inserts described herein, it is beneficial to control a ratio of a mass relative to the mass of the club head such that:
where R is the lower limit (%), mw is the mass of the weight structure (or the combined mass of multiple weight structures), and mh is the mas of the golf club head. Preferably, R is 8.0%. Even more preferably, R is 10%.
According to one or more embodiments, to achieve a beneficial increased mass relative to the material of the golf club head, a weight structure for a putter-type golf club head includes a heel insert and a toe insert, each insert being made of a tungsten nickel alloy. Compositions of the tungsten nickel alloys for the heel insert and the toe insert may be different to provide a denser material for the toe insert.
As shown in
According to one or more embodiments, to beneficially minimize CGD while also beneficially increasing Izz, a blade-type putter head includes a weight structure comprising a toe insert having a mass that is at least 15.0 g greater than a mass of a heel insert. Preferably, the mass difference is about 21 g. Preferably, the toe insert is about 41 g.
According to one or more embodiments, to beneficially minimize CGD while also beneficially increasing Izz a mallet-type putter head includes a weight structure comprising a toe insert having a mass that is at least 4.0 g greater than a mass of a heel insert. Preferably, the mass difference is about 7 g. Preferably, the toe insert is about 23 g.
In one or more embodiments, the weight insert is located proximate the face plane, but may be obscured from view. For example, a face plate 1101, as shown in
According to one or more embedment's, the central insert (e.g., 709) or faceplate (e.g., 1101) may have a pattern designed to control ball speed upon impact. In addition to CGD and Izz, ball speed on impact can affect the azimuth of off-center hits, both vertically and horizontally. In particular, it is desirable for ball speed to be equal for both on-center and off-center hits. However, an off-center hit, particularly in lower MOI putter heads, can result in reduced ball speed. Thus, it is desirable to use a pattern on the face of the putter that normalizes ball speed such that the ball speed on a center hit is substantially equal to the ball speed on an off-center hit, no matter where on the face the ball is struck. An example of one such pattern is shown in
As can be seen in
The specific location, pattern, depth, and/or width of the groves can be selected to carefully control the amount of striking face that will contact the ball in any one location. For example, to beneficially control the amount of striking face that will contact the ball, it is preferable that the groove depth is no less than 0.1 mm and no more than 0.3 mm. To beneficially control the amount of striking face that will contact the ball, it is preferable that the groove width is 0.62 mm in the plane of the striking face when measured in a heel-toe direction at the vertical center of the face and 0.51 mm in the plane of the striking face in a direction perpendicular to the edges of the groove.
Further, to beneficially control the amount of striking face that will contact the ball, the groove spacing will be depend on the overall geometry and mass distribution of the club head because clubs with different geometries and/or mass distributions (quantified, e.g., by MOI) will have a different amount of rotation for a similarly located off-center hit. For example, for the club head 100 shown in
The central insert 709 or face plate 1101 is preferably formed with the above described groove patterns by metal injection molding. However, a striking face having the groove patterns need not be part of a separate face plate or insert. For example, a putter head's main body can comprise such a striking face, and the grooves can be formed on the striking face by milling or etching.
While various features have been described in conjunction with the examples outlined above, various alternatives, modifications, variations, and/or improvements of those features and/or examples may be possible. Accordingly, the examples, as set forth above, are intended to be illustrative. Various changes may be made without departing from the broad spirit and scope of the underlying inventive principles.
