EP0927563A2

EP0927563A2 - Metal wood club head and club

Info

Publication number: EP0927563A2
Application number: EP98310785A
Authority: EP
Inventors: designation of the inventor has not yet been filed The
Original assignee: Orlimar Golf Co
Current assignee: Orlimar Golf Co
Priority date: 1997-12-31
Filing date: 1998-12-30
Publication date: 1999-07-07
Also published as: AU2099699A; WO1999033530A1; JPH11262548A; EP0927563A3

Abstract

The disclosure relates to a metal wood golf club head (10) comprising having a face (20), sole (13), toe (14), heel (15) and hosel (17). A thin, hard metal insert (18) is joined to an opening in the face (20). A plurality of grooved runners (30 to 32) extend rear-to-front along the sole of the body terminating at the leading edge of the body, and a plurality of weights (23, 24, 25) are mounted in recesses (32 to 35) in the surface of the runners (30 to 32). Preferably the face insert is maraging metal and the weights are tungsten copper.

Description

The present invention relates to golf clubs and, in particular, to metal woods including fairway woods and drivers.
As used here "woods" refers to drivers and fairway woods and "metal woods" refers to metal embodiments of such clubs, that is, to metal drivers and to metal fairway woods.
The club heads of prior art metal woods typically comprise two sections which are joined or welded along a generally horizontal plane above or at the top of the sole.
In one aspect, the present invention is embodied in a metal wood golf club head, comprising: a first member forming a hollow body of a metal wood club head and comprising a sole, a toe, a heel and a rear, the first member having a periphery at the front thereof; and a second, face member having a periphery. The first member and the second member are joined along their peripheries. In a preferred embodiment, the club head according to the present invention includes recessed rails extending along the sole in a rear-to-front direction and terminating proximate the front periphery of the face member. In yet another aspect, the club head according to the present invention comprises a plurality of weights in the sole. In another aspect, the club head according to the present invention comprises a C-shaped groove extending about a periphery of the sole and having ends thereof terminating adjacent the front edge.
In yet another aspect, the present invention is embodied in a metal wood club head and club, in which the club head comprises a first component in the form of a body which includes the face, sole, heel, hosel, toe and rear of the club head; a second component in the form of an insert which forms the face of the club head; and a third component comprising a plurality of weights in the sole. Preferably, the club head comprises a plurality of adjacent grooves and runners extending along the sole, in the direction from the front or leading edge of the face or sole to the rear.
Other embodiments and arrangements are described in the accompanying specification and drawings.
The present invention is described below with reference to the drawing, in which:
FIGURE 1 is a face (front) elevation view of a metal wood in accordance with the present invention.
FIGURE 2 is a rear elevation view of the metal wood of FIGURE 1.
FIGURE 3 is a heel end elevation view of the metal wood of FIGURE 1, taken generally from a rear perspective toward the heel of the club head.
FIGURE 4 is a bottom plan view of the metal wood of FIGURE 1.
FIGURE 5 is a vertical section view taken along line 5-5 in FIGURE 4.
FIGURE 6 is a vertical section view taken along line 6-6 in FIGURE 5.
FIGURE 7 is a perspective view of the metal wood of FIGURE 1, taken generally from a bottom or perspective looking from the heel toward the toe of the club head, and illustrating the face plate or insert and the sole weights or inserts in exploded relationship to the body.
FIGURES 1-7 depict a preferred embodiment 8 of a metal wood golf club and the associated club head 10 according to the present invention. Referring initially to the elevation views of FIGS. 1-3 and the exploded inverted perspective view of FIG. 7, the club head 10 comprises a first component 12 in the form of a thin hollow body or shell which includes a number of sections, including sole 13, toe 14, heel 15, rear side 16, hosel 17 and face 20; a second component 18 in the form of an insert or plate which completes and effectively is face 20; and a third component 22 in the form of a plurality of relatively heavy weights 23, 24, 25 mounted in the sole 13, preferably non-protruding and flush with the surface of the sole.
In contrast to the prior art's typical horizontal joining of soleplate and upper body to form a club head, according to the present invention, the club head 12 comprises a thin hollow body or shell, formed for example by casting; and the component 18 is a thin plate or insert which is inserted into a correspondingly shaped opening 36 in the front of the club head body 12, completing the face 20. The back edge of the periphery of the plate or insert 18 is mounted against a recessed lip 37 extending peripherally around the opening 36 and the outside edge of the periphery of the plate or insert fits inside a thin rim along the peripheral edge 41 of the face 20. Edge 41 is also the leading edge of the club head. The periphery of the face or insert 18 thus is at the leading edge. Please note, the club head body 12 may be is cast in two pieces: the main section which has front opening 36 and a top opening; and a cap. The cap is inserted into the top opening and welded in place, completing the body 12.
As shown most clearly in FIGURE 3, the hosel 17 has an internal bore 19 into which golf club shaft 26 is inserted and joined.
Referring now to FIGURES 2, 4 and 7, preferably the club head 10 further comprises a plurality of recessed rails, illustratively three runners 30-32 separated by a pair of grooves 27 and 28. The runners and grooves extend along the heel 13 in a rear-to-front direction generally perpendicular to the plane of the face 20. As alluded to elsewhere, the use of the two members--the one-piece club head body 12 and the face insert 18--which are joined in the face itself eliminates the prior art joining line, which would interfere with and limit forward extension of any grooves and runners. In contrast, the member 12 and face insert 18 permit the use of extended, continuous, long grooves and runners which extend to the leading edge 41 of the club head. As shown in FIGURES 4 and 7, preferably the grooves have a reverse chisel configuration defined by a relatively flat orientation at the rear which angles upwardly at the front. Also, as alluded to previously, weights 23-25 are mounted in recesses 32-35 in the runners 30-32.
The extended length, runners and reverse chisel grooves facilitate the club's ability to track and square through the shot. Drag is reduced in the sole area. In prior art club heads, normally the lower leading edge strikes the ground. In my club, the use of grooves and runners, recessed rails, which extend to the leading edge, reduces the area which strikes the ground, and allows the club to release from the initial dig into the turf.
Referring to FIGS. 2, 4 and 7, in another aspect, a C-shaped groove 42 is formed around the periphery of the club head sole 13, with ends terminating at the front of the body 12 just behind the leading edge 41. The groove 42 is both cosmetic and functional, in that it is thought to impart a heavier, directed wind tunnel-generated appearance, and in that it permits the sole 13 to extend lower, lowering the center of gravity.
In a presently preferred embodiment, the club head body 12 and the hosel 17 are 17-4 stainless steel. The body 12 is a thin hollow shell casting having a wall thickness t_h, FIG. 7, which varies from approximately 1.5 mm. in the top cap to approximately 3.5 mm. in the sole. The shaft 17 is graphite. Preferably the face insert 18 is maraging metal, most preferably maraging 11% chrome, 11% nickel carbon steel. The thickness, t_f, of the face insert is about 1.75 - 2.2 mm. thick, and its Rockwell hardness (HRc) is 52-55. The sole inserts or weights 23-25 preferably are tungsten copper, most preferably 70% tungsten, 30% copper by weight (50% tungsten, 50% copper by volume). The thickness of the inserts, t_w, is about 1.5 mm. Metal epoxy is used to join the hosel and shaft together. Preferably, the face insert and the sole weights are joined to the body by brazing to provide effective joinder and to retain the strength and hardness of the metals. Presently, the club 8 is made with loft angles spanning the approximate range 9° to 27°. The stated hardness of the maraging steel is approximately twice the hardness of stainless steel. The tensile strength of the maraging metal is approximately 35% greater than the strength of B titanium. The tungsten copper metal is approximately 25%-30% heavier than the same volume of lead.
In an exemplary embodiment, the width of the grooves 27 and 28 is approximately 0.4375" (7/16 inch) and their length in the direction front-to-rear (face-to-rear) is about 2" as measured along the longer, outside edge.
The insert 23 is rectangular and the length thereof extends generally in a direction front-to-rear. The width is approximately 0.25" (1/4" inch) and the length is approximately 1.1875" (1 and 3/16 inches). The outside inserts 24 and 25 also extend generally in a direction front-to-rear, and have an elongated, approximately isosceles triangle configuration in which the base is situated at the face or front end and the elongated, approximately equal length sides are oriented front-to-rear and taper inwardly along the length. The width of the inserts 24 and 25 is approximately 0.25" (1/4 inch) at the widest point adjacent the face end or base, and tapers to a width of approximately 0.03125" (1/32 inch) at the rear. The outside inserts 24 and 35 are approximately 1.1875" (1 and 3/16 inches) long.
The face plate or face insert 18 of an exemplary fairway wood is approximately 1" in height, top-to-bottom and approximately 3.25" (3 and 1/4") wide or long, in a horizontal direction. The height and width of the face plate 18 of an exemplary driver are approximately 1.375" (1 and 3/8 inches) and 3.3125" (3 and 5/16 inches), respectively. The periphery of the driver face plate or insert 18 also extends to the leading edges at the top and bottom of the club face. As shown in FIGS. 6 and 7, in both the fairway wood and driver embodiments, the periphery of the plate or insert 18 extends to the leading edges or periphery of the club at the top and at the bottom (sole) thereof and forms the club face.
It should be noted that the face plate 18 curves slightly rearwardly both top to bottom and side to side (vertically and horizontally) and preferably is devoid of internal ribs or other protuberances.
Other materials will be chosen by those of usual skill in the art. By way of example but certainly not limitation, the inserts may be brass and the shaft may be carbon steel.
In one approach, to assemble the metal wood, the face insert 18 and the weights 23-25 are joined to the club head body 12 by brazing. Then, the shaft 26 is joined to the club head by inserting epoxy into the hosel bore 19 and inserting the shaft into the hosel.
In attempting to increase distance, golf designers have increased the size of drivers, frequently with some loss of control. In contrast, the fairway wood club head 10 and club 8 is a shallow face head design with weighted, grooved sole runners which combine to provide driver length; fairway wood accuracy; high trajectory; facility in launching the ball, that is, getting the ball airborne; and ease of set-up in difficult lies such as shallow lies. Specific factors which contribute to this combination of improvements are described below. Except for the shallow face, the driver possesses the same factors which lead to the described combination of improvements.
First, the hard, thin, slightly curved face which is supported around the periphery (that is, is not supported along the interior of the face) gathers impact energy behind the ball and launches the ball with high velocity. The thin face gathers all impact energy directly behind the ball, unlike so-called "oversized" drivers, which lose energy across their large surface.
Second, the thin wall, relatively light weight club head body and face insert and the weighted sole provide a very low center of gravity, which facilitates getting a struck ball airborne with high trajectory, and increases the size of the sweet spot and produces stability with accuracy through impact.
Third, the recessed runners or rails extend to but not into the face of the club head, improving contact with the ball in difficult lies. In short, the runners make it easier to hit off difficult lies, including shallow/thin lies such as in divots.
Finally, but not exhaustively, the graphite shaft combines with the other features to provide improved distance and "feel".
Quantitative tests of length and accuracy were obtained at an independent test facility using a robotic swing arm. A so-called TRIMETAL™ fairway wood from assignee which was a 13° loft version of the most-preferred design described above ("club 8"), was compared to a Callaway Big Bertha driver ("club A") and a titanium Taylor Made Burner Bubble driver ("club B"). The average ball carry distance for club 8 exceeded the average ball carry distance for clubs A and B approximately 7.25 yards and 10.25 yards, respectively. Average dispersion (the average distance balls land from a straight line between the robot and target) was 15.21 feet for club 8, compared to 75.67 feet for club A and 21.07 feet for club B. Please note, average dispersion is a measure of accuracy and the extent to which the gearing effect compensates for off-center (heel and toe) hits. Based upon the above results, in comparison to so-called "oversized" drivers, club head 10/club 8 is characterized by longer distance and greater accuracy.
Having thus described preferred and alternative embodiments of the present invention, those of usual skill in the art will readily derive modifications and extensions within the scope of this invention and limited only by the extent of the present claims.

Claims

A metal wood golf clubhead, comprising: a first member forming a hollow body of a metal wood club head and comprising a sole, a toe, a heel and a rear, the first member having a periphery at the front thereof; a second, face member having a periphery; and the first member and the second member being joined along their peripheries.
A metal wood golf club head, comprising: a first member forming a hollow body of a metal wood club head and comprising a sole, a toe, a heel and a rear, the first member having a periphery at the front thereof; a second, face member having a periphery; the first member and the second member being joined along their peripheries; and at least a pair of grooves extending along the sole in a rear-to-front direction and terminating proximate the front periphery of the face member.
The metal wood golf club head of claim 2, wherein the first member includes a front edge and the sole extends to the front edge, and wherein the club head further comprises a C-shaped groove extending about a periphery of the sole and having ends thereof terminating adjacent the front edge.
A metal wood golf club head, comprising: a first member forming a hollow body of a metal wood club head and comprising a sole, a toe, a heel and a rear, the first member having a periphery at the front thereof; a second, face member having a periphery; the first member and the second member being joined along their peripheries; the first member including a front edge and the sole extending to the front edge; and the club head further comprising a C-shaped groove extending about a periphery of the sole and having ends thereof terminating adjacent the front edge.
A metal wood club head, comprising: a first thin hollow body member comprising face, sole, toe, heel and rear sections; the face comprising a peripheral edge circumscribing an opening; a thin second insert member of size corresponding to the size of the opening in the face and having a peripheral edge fitted and joined to the peripheral edge of the face; a plurality of recessed rails extending in the rear-to-front direction along the sole of the first member to the leading edge of the club head body; and a plurality of weights inserted in the sole runners.
The metal wood club head of claim 5, further comprising a C-shaped groove extending about the periphery of the sole and having ends thereof terminating adjacent the front edge.
The metal wood club head of claim 5 or 6, wherein the club head body is stainless steel and is several millimeters thick.
The metal wood club head of any of claims 5 to 7, wherein the face insert is maraging steel.
The metal wood club head of claim 8, wherein the face insert is 11% chrome, 11% nickel, carbon steel.
The metal wood club head of claim 8, wherein the face insert is 11% chrome, 11% nickel carbon steel and the thickness of the face insert is about 1.75 - 2.2 mm.
The metal wood club head of any of claims 1 to 10, wherein the thickness of the face insert is 1.75 - 2.2 mm.
The metal wood club head of any of claims 1 to 11, wherein the sole inserts are tungsten copper metal.
The metal wood club head of claim 12, wherein the sole weights are tungsten copper metal and the thickness of the sole weights is about 1.5 mm.
The metal wood club head of claim 12, wherein the sole weights are 70% tungsten, 30% copper by weight.
The metal wood club head of claim 12, wherein the sole weights are 70% tungsten, 30% copper by weight and the thickness of the sole weights is about 1.5 mm.
The metal wood club head of any of claims 5 to 15, further comprising a fiberglass shaft mounted in a hosel in the head.