1. Field of the Invention
The invention generally relates to a golf club head with a channel area in the sole to contribute to straight, long-distance drives.
2. Background
When people play golf, they would like to be able to hit a golf ball a long distance in the right direction. Driver-style golf clubs are designed to a have a large face with a sweet spot that hits the ball far. Club designers have tried different structures in attempts to improve the sweet spot and hitting distance of drivers. For example, U.S. Pat. No. 7,294,064 to Tsurumaki shows an elastically deformable groove or recess to increase coefficient of restitution and move sweet spot downwards. Other clubs with some such feature are shown in U.S. Pat. No. 8,529,368 to Rice; U.S. Pat. No. 7,582,024 to Shear; U.S. Pat. No. 7,572,193 to Yokota; U.S. Pat. No. 7,500,924 to Yokota; U.S. Pat. No. 7,396,293 to Soracco; U.S. Pat. No. 6,887,165 U.S. Pat. No. 5,735,754 to Antonious; U.S. Pat. No. 5,603,668 to Antonious; U.S. Pat. No. 1,835,718 to Morton; U.S. Pub. 2013/0029779 to Stites; U.S. Pub. 2012/0143452 to Burnet; U.S. Pub. 2012/0142447 to Boyd; U.S. Pub. 2012/0196703 to Sander; U.S. Pub. 2012/0244960 to Tang; U.S. Pub. 2012/0220387 to Beach; U.S. Pub. 2007/0117648 to Yokota; U.S. Pub. 2007/0026961 to Hou; U.S. Pub. 2004/0192463 to Ando; and U.S. Pub. 2002/0183134 to Allen.
Unfortunately, introducing a structure to accomplish one goal can compromise another. Some golfers find that, despite the distance of their drives, the balls tend to hook or slice unpredictably. In fact, it may be found that prior art club heads with a channel in the sole are notoriously hard to hit, sending the ball in all directions, and thus negating the intended improvement of the channel.
The invention provides a golf club with a channel that includes a recess set apart from an adjacent sole surface by at least one curved surface defining a ramp disposed at an angle intermediate the orientation of the channel wall and the sole surface. The ramp is oriented such that, during a high speed drive, the ramped portion of the sole may distribute and neutralize torsional stresses, dampening unwanted and unpredictable twisting that can be introduced or amplified by prior art channel structures. One insight of the invention is that adding an elastically deformable channel to a driver head can destabilize the structure, allowing the club head to twist, shear, or compress non-uniformly and transfer momentum non-uniformly to the strike face during the down stroke of a high-speed drive or at impact. A club head may twist or shear because the down stroke stresses the club along certain vectors and the prior art structure is compressible along that vector. An inclined surface, such as a ramp with a shallow slope, can introduce a plane of material extending in parallel to a component of such a vector and that material can resist compression or deformation. Preferably, that first ramp is adjacent another second ramped portion that is sloped in the same direction but at a steeper angle, with an opposed third ramped surface facing the first and second ramped surfaces. Thus a club head that includes a channel area with a groove that is buttressed by a shallow ramp will resist non-uniform deformation and non-uniform momentum transfer to the face with the result that shots will fly straight, and the club head will provide the full and intended benefit of a channel in the sole—a high coefficient of restitution and a large sweet spot in a club head that hits true. The channel area or groove preferably runs in a heel-to-toe direction substantially parallel to the face and close (e.g., within a few centimeters) to the face.
In certain aspects, the invention provides a golf club head having a crown, sole, heel portion, toe portion, and face cooperating to define a club head body. A hosel extends upwards from the body. The club head includes a channel area extending along an outer surface of the sole from the heel portion towards the toe portion. The channel area includes a groove disposed alongside a ramp with a shallow slope with respect to the horizontal when the club head is at address.
The groove may include two opposed, inward-facing walls such as a fore facing inward wall and an aft-facing inward wall. The aft-facing inward wall can have a steep slope with respect to the horizontal when the club head is at address. The shallow slope may be between 5° and 20° and the steep slope is between 20° and 80°. In some embodiments, the shallow slope is between 10° and 20° and the steep slope is between 30° and 60°. A heel-toe length of the channel may be between about 5 cm and about 15 cm. A face-aft width of the channel may be between about 0.2 cm and about 3 cm. A face-aft width of the ramp may between about 0.1 cm and about 1.5 cm.
In some embodiments, the club head is a hollow club head such as a driver, fairway wood, or hybrid.
In certain aspects, the invention provides a golf club head with a crown, sole, heel portion, toe portion, and face cooperating to define a club head body as well as a hosel extending upwards from the body and an inclined surface transitioning from a downward-facing portion of the sole surface to a narrow furrow in the sole. The furrow preferably extends from the heel portion to the toe portion. The inclined surface may extend along substantially an entirety, or only a part, of the furrow. A portion of the inclined surface may contain a portion of an idealized conical surface. The idealized conical surface defines an axis of a cone that is parallel to an axis of percussion of the club head or to a horizontal axis passing in a face-aft direction through a geometric center of face when the club head is at address.
In certain aspects, the invention provides a golf club head with a crown, sole, heel portion, toe portion, and face cooperating to define a club head body as well as a hosel extending upwards from the body and an inclined surface transitioning from a portion of a surface of the club head to a narrow furrow in the club head.
In certain aspects, the invention provides a golf club head that has a crown, sole, heel portion, toe portion, and face cooperating to define a club head body and a hosel extending upwards from the body. A channel extends across a surface of the club head. A cross-sectional profile of a portion of the channel has, when the club head is at address, a gently inclined portion forming a first angle with the horizontal and a steeply inclined portion forming a second angle with the horizontal. Preferably, the channel extends across the sole. In some embodiments, the first angle is between 5° and 20° and the second angle is between 20° and 80°. Preferably, the gently inclined portion and the steeply inclined portion extend for a distance across the sole substantially in a heel-toe direction. That distance may be greater than about 4 cm.
In certain embodiments, the steeply inclined portion provides part of a wall of a groove in the sole. The groove can be substantially parallel to the face and spaced away from the face by at least a setback distance over a majority of a length of the groove. That setback distance may be between about 1 cm and about 5 cm. Preferably, the gently inclined portion is disposed between the face and the groove. In certain embodiments, the groove comprises a depth, with respect to a predominant surface of the sole, between about 1 mm and about 10 mm.
The invention provides a golf club head with a structure designed to improve a coefficient of restitution or increase the size of a sweet spot without introducing structural instability into the club head that leads to unpredictable twists and uncontrollable hooking or slicing. Without being bound by any mechanism of action, it is theorized that an elastically deformable groove in a club head can compress non-uniformly during a swing due to torsional stresses introduced during a down-swing (i.e., the club head can squeeze more on one side than the other in a manner similar to the compression of a corridor connection between cars of a passenger train as it rounds a curve). It is possible that the predominantly upright nature of the internal walls of a deformable groove and the narrow connection between them does little to resist non-uniform connection. Accordingly, the invention provides an area of material that is sloped, with respect to the surrounding area of the club head, less than the internal walls of a deformable groove. Specifically, a preferred embodiment includes a groove or slot on the sole that is substantially parallel to the face and that defines at least three surface: two that are opposed, steeply sloped surfaces facing one another, and a third that is gently sloped, providing a transition from the deeper groove to the sole surface. The gently sloped portion allows the deeper groove to still provide its beneficial contribution to sweet spot and coefficient of restitution, but may strongly resist the non-uniform compression and non-uniform momentum transfer to the strike face resulting from torsional stresses of a hard downward swing. A channel area with a gently sloped portion adjacent a deeper groove may be located anywhere on a club head. For example, a channel area may be substantially parallel to a face and extend across a crown or sole (either centered or off-center). In a preferred embodiment, the channel area extends across the sole.
Channel area 105 may be described according to dimension. A length of channel area 105 may be taken to be the distance between heel boundary HB and toe boundary TB. A width W of channel area 105 can be taken to be a distance between a foremost and aft-most part of sloped area 107 and channel 109. The foremost part of channel area 105 can be described as being spaced away from face 123 by a setback distance S. Sloped area 107 has a ramp width R measured within a horizontal plane when the club is at address and preferably between about 0.1 cm and about 5 cm. Groove 109 can be taken to have a width equal to W−R.
In certain embodiments, including a channel area 105 on an outer surface of sole 103 will create a rib-like structure on an inside surface of sole 103. In particular, groove 109 having the form of a narrow furrow adjacent the inclined surface 107 may protrude upwards on an inside of sole 103.
Channel area 105 may be described with respect to a section (i.e., a drawing of club head 101, sole 103, or channel area 105 as it would appear if cut straight through in a given plane).
One significant improvement over prior art structures may be provided by a channel that has two adjacent wall portions, a first with a shallow slope angle θKL and a second with a steeper slope angle θKM. Particularly in cooperation with sole 103, these areas lying substantially within a plane or a curved plane may add planar material that resists stress in a plurality of different vectors. It may be found that the shallow slope angle θKL should be between about 1° and about 20° and that the steep slope angle θKM should be between about 20° and about 70°. Additionally, those portions are described here as defining angles, but they need not be surfaces that extend strictly within planes. Gently curved or rolled surfaces are included within the scope of the invention as are areas in which the gently inclined portion 107 curves continually into the steeply inclined portion. In certain aspects, the invention provides a club head in which a cross-sectional profile of a portion of a channel area 105 has, when the club head is at address, a gently inclined portion 107 disposed at an angle to the horizontal and a steeply inclined portion disposed at a second angle to the horizontal and in which the gently and steeply inclined portions are each and all substantially curved forming a continually curving cross sectional profile.
Golf club heads of the invention can be made by methods and materials known in the art.
Construction of club head 101 may be via known methods. U.S. Pat. No. 7,294,064; U.S. Pat. No. 8,529,368 to Rice; U.S. Pat. No. 7,582,024 to Shear; U.S. Pat. No. 7,572,193 to Yokota; U.S. Pat. No. 7,500,924 to Yokota; U.S. Pat. No. 7,396,293 to Soracco; U.S. Pat. No. 6,887,165 U.S. Pat. No. 5,735,754 to Antonious; U.S. Pat. No. 5,603,668 to Antonious; U.S. Pat. No. 1,835,718 to Morton; U.S. Pub. 2013/0029779 to Stites; U.S. Pub. 2012/0143452 to Burnet; U.S. Pub. 2012/0142447 to Boyd; U.S. Pub. 2012/0196703 to Sander; U.S. Pub. 2012/0244960 to Tang; U.S. Pub. 2012/0220387 to Beach; U.S. Pub. 2007/0117648 to Yokota; U.S. Pub. 2007/0026961 to Hou; U.S. Pub. 2004/0192463 to Ando; and U.S. Pub. 2002/0183134 to Allen show features and constructions that may be modified for incorporation in a club head of the invention and the content of each of those references is incorporated by reference for all purposes.
As used herein, the word “or” means “and or or”, sometimes seen or referred to as “and/or”, unless indicated otherwise.
References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
Various modifications of the invention and many further embodiments thereof, in addition to those shown and described herein, will become apparent to those skilled in the art from the full contents of this document, including references to the scientific and patent literature cited herein. The subject matter herein contains important information, exemplification and guidance that can be adapted to the practice of this invention in its various embodiments and equivalents thereof.
This application claims the benefit of, and priority to, U.S. Provisional Application 61/824,092, filed May 16, 2013, the contents of which are incorporated by reference.
Number | Date | Country | |
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61824092 | May 2013 | US |