Patent Application
20060052181
This invention relates generally to golf clubs and, in particular, to so-called metal wood drivers.
Recent developments in golf club design have included improvements in drivers, which are clubs used primarily to strike a golf ball resting on a golf tee. These improvements have resulted in drivers with club heads consisting of a hollow shell usually made of metal, such as steel, aluminum, or titanium. One example of a golf club head consisting of a hollow metal shell is disclosed in U.S. Pat. No. 5,851,160 to Rugge, et al. In an effort to obtain better and better performance from these hollow metal wood drivers, however, golf club manufactures have increased the head volume from a moderate volume of 250 cubic centimeters as disclosed in Rugge, et al. to over 400 cubic centimeters in recent years. The striking face of a metal wood driver must be of a certain minimal thickness in order to withstand the impact forces generated upon impact with a golf ball. Accordingly, as head size increases, less and less material is available for fabricating the crown, sole and skirt of the club head while maintaining the club head of these super-oversized drivers within acceptable weight limitations (i.e., around 200 grams mass).
More recently, in U.S. Pat. No. 6,471,604, one golf club manufacturer has suggested a club head having a metallic face bonded to an aft body composed of a non-metal material such as a composite or thermoplastic material. The lightweight plastic rear body enables more metal to be dedicated to the striking face, however, many golfers dislike the impact sound produced by a club head having a low resonance, highly damped non-metallic rear body. Moreover, because of the discontinuity between the all-composite or thermoplastic rear body and the striking face, the striking face is not significantly supported by the rear body. Consequently, more material must be dedicated to striking face itself, thereby canceling out much of the weight savings attributable to the non-metallic rear body.
Accordingly, what is needed is a club head having a metal-organic composite rear body, which is integral to the striking face and therefore maintains some of the stiffness (and frequency) of a fully-metallic rear body, while still providing a lightweight rear body structure.
The present invention comprises a golf club head formed of a hollow body having a metallic face and a rear body portion forming a shell at least a portion of which is made of a metal-organic composite material. According to a preferred embodiment, the rear body portion of the club head includes a metallic stringer that extends along a crown-skirt interface and a plurality of ribs intersecting the metallic stringer to form a lattice frame, the openings of which are filled with an organic composite material such as graphite epoxy. In the preferred embodiment, the lattice frame forms at least a portion of the crown of the rear body portion. An additional aperture formed in the skirt is also filled with the same graphite epoxy material. Because the graphite epoxy is lighter than the surrounding metal lattice frame, the rear body portion of the golf club head is lighter than a comparable all metal club head. Yet, the presence of the metallic stringer and lattice frame renders the metal-organic composite rear body portion substantially stiffer than a comparable all-composite rear body portion.
The present invention will be better understood from a reading of the following detailed description, taken in conjunction with the accompanying drawings figures in which like references designate like elements and, in which:
The drawing figures are intended to illustrate the general manner of construction and are not necessarily to scale. In the detailed description and in the drawing figures, specific illustrative examples are shown and herein described in detail. It should be understood, however, that the drawing figures and the detailed description are not intended to limit the invention to the particular form disclosed but are merely illustrative and intended to teach one of ordinary skill how to make and/or use the invention claimed herein and for setting forth the best mode for carrying out the invention.
With reference to
The region surrounding apex 26 forms an arcuate perimeter region 32 that smoothly blends the high crown curve of apex 26 into the low crown curve of crown 20 and skirt 24. Arcuate perimeter region 32 preferably extends 0.700 inches above and 0.700 inches below the peak of apex 26, preferably 0.350 inches above and 0.350 inches below the peak of apex 26 and most preferably about 0.250 inches above and 0.250 inches below the peak of apex 26. Arcuate perimeter region 32 is unsupported above and below by any of the metal forming hollow body 12 for at least a portion of its span.
Hollow body 12 may be assembled from a series of forged metal pieces that are welded or brazed together, but in the illustrative embodiment of
Apertures 34 and 36 are filled with a material that is of lower density than the relatively denser metallic hollow body 12. The material may be a lightweight non-metallic material 44 such as thermoplastic, or thermoset plastic, or preferably a fiber reinforced organic resin such as fiberglass-epoxy, fiberglass-polyester, ceramic-fiber epoxy, aramid-epoxy or other fiber-organic resin composites. Preferably, the non-metallic material comprises graphite-epoxy, which is laid up on the interior surface 46 (
In the illustrative embodiment of
By eliminating metal from portions of the crown 20 and the skirt 24, as represented by apertures 34 and 36, the illustrative embodiment of
With reference to
With reference to
Although certain illustrative embodiments and methods have been disclosed herein, it will be apparent from the foregoing disclosure to those skilled in the art that variations and modifications of such embodiments and methods may be made without departing from the spirit and scope of the invention. Accordingly, it is intended that the invention should be limited only to extent required by the appended claims and the rules and principals of applicable law.
