Golf club head with sole bevel indicia
BACKGROUND OF THE INVENTION 
     This application is a continuation-in-part of prior U.S. patent application Ser. No. 08/414,552 filed Apr. 6, 1995, which is a continuation-in-part of prior U.S. application Ser. No. 08/119,622 filed Sep. 13, 1993, now U.S. Pat. No. 5,409,229, which is a continuation-in-part of prior U.S. application Ser. No. 07/999,250 filed Jan. 19, 1993, now U.S. Pat. No. 5,301,946, which is a continuation-in-part of prior U.S. application Ser. No. 07/921,857 filed Aug. 5, 1992, now U.S. Pat. No. 5,282,625. 
    
    
     This invention relates generally to golf clubs, and more particularly to golf club irons of improved construction, wherein structure is provided to enable ready club identification. 
     In the past, numbers have been applied to the soles of club heads, near the head front walls, for club identification. Such number application was achieved as by embossing. Since turf including dirt can fill into and cake in embossed recesses, there is need for means to reduce exposure of embossed numeral recesses to direct impact with the turf, during a golf swing. There is also need for embossed numeral placement on a head in such manner as to enable downward bulging of the sole, forward of the embossed numeral. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide method and means meeting the need referred to above, as well as providing additional unusual advantages, as will appear. 
     Basically, the invention is embodied in a golf club head having a body defining a heel, toe, top wall, sole defining a bottom wall, and a front wall defining an upwardly and rearwardly inclined front face, and comprising 
     a) a bottom wall having a local bevel located medially of the head and extending rearwardly and upwardly toward the rear wall, the bevel typically being flat, 
     b) there being indicia on the local bevel. 
     The head typically comprises an iron; and the indicia typically comprises a number that designates the club number, and that is embossed in or recessed in the bevel surface metal. Since the embossed numeral is then located rearwardly of the main extent of the sole, it is protected from direct impact with the turf, and the forward extent of the sole may be downwardly bulged, to receive such impact, producing &#34;bounce&#34; for aiding club head lifting from the turf, the bulge also protecting the embossed numeral from such impact. 
     Another object is to provide a set of irons which have bottom surface bevels with embossed identifying numerals thereon. 
     Another object is to provide such an iron wherein the front wall has a rearwardly exposed rear side, and including composite structure on the rear side of said front wall for providing swing weight adjustment. 
     Yet another object is to provide such an iron having a rear cavity and an associated undercut recess, above the level of the bevel. As will appear, the rear cavity typically forms a main recess located rearwardly of the front wall, and the undercut recess is located rearwardly of the front wall and extends outwardly from the main recess toward at least one of the following: 
     i) said top wall 
     ii) said bottom wall 
     iii) said toe 
     iv) said heel, 
     A further object includes provision of a composite adhered to the rear side of the front wall, above the level of the embossed bevel, the composite including 
     i) a selected swing weight adjusting intermediary layer, and 
     ii) a rearwardly facing layer providing identification graphics which are rearwardly visible. 
     Such graphics may define a medallion, as will appear. 
     These and other objects and advantages of the invention, as well as the details of illustrative embodiments, will be more fully understood from the following specification and drawings, in which: 
    
    
     DRAWING DESCRIPTION 
     FIG. 1 is a rear elevation of the head of a #6 iron of a golf club set incorporating the invention; 
     FIG. 2 is a section taken on lines 2--2 of FIG. 1; 
     FIG. 3 is a section taken on lines 3--3 of FIG. 1; 
     FIG. 4 is a top plan view of the FIG. 1 head; 
     FIG. 5 is a view showing swing weight determination; 
     FIG. 6 is an enlarged, fragmentary section taken through a swing weight adjusting composite; 
     FIG. 7 is a view showing application of a composite to a golf club head; 
     FIG. 8 is a still further enlarged, vertical section taken through a swing weight adjusting composite, as used on a golf club iron head; 
     FIG. 9 is a bottom view of a head, as for example the head of FIGS. 1-8, and having a numerically embossed bevel; 
     FIG. 9a shows a set of heads having embossed bevels; and 
     FIG. 10 is a fragmentary section taken on lines 10--10 of FIG. 9. 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1-3, 9 and 10 illustrate a golf club head in the form of a #6 iron of a set of irons, having a body 11 defining a heel 12, toe 13, top wall 14, a sole 15. The rear of the sole is beveled at 15c&#39; as shown, the bevel being flat or substantially flat and inclined upwardly and rearwardly relative to the bottom of the sole. 
     The body also defines an upwardly and rearwardly inclined front face 16 at the frontal side of an associated front wall 17. A hosel is shown at 18 and integrally joins the head via offset 18a; and a shaft 19 extends into a through bore 18b in the hosel as shown, and is anchored therein in a suitable manner, as for example by adhesive or mechanically. See for example U.S. Pat. No. 5,042,806, incorporated herein by reference. The head and hosel may consist of a one-piece, metallic steel casting, other metals and alloys being usable. 
     FIG. 9 shows an identifying number 6 embossed in the bevel 15c&#39;, which is located medially of the head length between the toe and heel. Each head of the set shown in FIG. 9a has a number embossed onto a rear bevel, i.e. numbers 1-9; and with advantages as referred to above. Each embossed numeral also typically extends in a flat plane at its associated bevel. 
     FIG. 10 shows that, forward of the bevel, the bottom surface of the sole is shallowly downwardly convex, i.e. arcuate or bulged, between the forwardmost extent of the bevel at 150, and the lowermost extent of the front wall, at 151. See downward bulge 152. This produces a bounce effect as the sole impacts the turf during a golf stroke, and the rearwardly and upwardly tapering or angled bevel reduces drag effect on the head, by the turf, as the head travels forwardly and upwardly during the stroke. Also, the embossed numeral &#34;6&#34; is located rearwardly and upwardly from the bulge, and from the forwardmost extent at 150 of the bevel forward arcuate edge. 
     The body defines two intersecting recesses related to rearwardly elongated body projections, typically extending rearwardly, as will be described, irrespective of the head front face angularity. The two recesses include a forwardly and rearwardly extending main recess 21, and an undercut recess 22 located directly rearwardly of the front wall and extending outwardly from the forwardmost extent of the main recess 21, toward at least one of the following: 
     i) the top wall 
     ii) the bottom wall 
     iii) the toe 
     iv) the heel, 
     Typically, the undercut recess portions 14a and 15a, associated with walls 14 and 15, are elongated directionally between the toe and heel, over the major length of the head, thereby enhancing certain benefits which include metal redistribution toward the upper and lower peripheries of the head, and projecting rearwardly at 24 and 25, for resisting twist of the head during stroking and ball impact. Such metal rearward redistribution, i.e., lengthening in a rearward and outward (enlarging effect) direction, as at 24 and 25, rearwardly of undercuts 14a and 15a, is believed to achieve momentum transfer from the metal portions 24 and 25, to the front wall and front face 16, in such manner as to maintain a greater time interval of front face contact with the ball during stroking, for better ball control. 
     This effect may be further enhanced by the provision of at least one elongated slit extending generally parallel to the front face 16 and spaced rearwardly from that face 16, to intersect undercut 14a and the upper surface of 24. 
     Note that such momentum transfer, visualized in the form of forward waves, is required to pass around and through the reduced thickness (i.e. web) forward portions 14b and 15b of the rearwardly projecting portions 24 and 25, and at the corners 54 and 55, as well as at regions 56 and 57 near the heel; and momentum or inertial travel through such restricted, narrowed regions 14b and 15b, and at 54-57, is facilitated by the outwardly concave curvature at 14c and 15c, or other similar thickness narrowing shape, bounding the outermost extents of the undercuts 14a and 15a. Enhanced performance is thereby achieved in terms of better ball stroking and directional control. 
     The undercut recess portions 12a and 13a, associated with the heel and toe, and associated metal redistribution rearwardly and functionally outwardly (i.e., enlarging effect) from those undercuts, at corners 54-57, contribute to and add to the same effects as described above for the undercut recess portions 14a and 15a at those corners. The undercut recess projects outwardly to an extent w 1  (which may vary, as shown); however, the front-to-rear thickness t 1  of the undercut recess is approximately as follows: 
     
         0.5t.sub.1 &lt;w.sub.1 &lt;1.5t.sub.1 
    
     The radii of the circular curvatures at 14c and 15c are typically between 0.150 and 0.160 inches for #1 through #7 irons; between 0.210 and 0.230 for #8 and #9 irons; and between 0.300 and 0.320 for a pitching wedge; however, these dimensions can vary somewhat. 
     In this regard, the rearward projections extending rearwardly from the toe and heel undercuts are elongated in relation to their thickness dimensions, showing that metal has been redistributed to those projections to enhance the effects described and without increasing the overall vertical dimension of the head. 
     Note also that the dimension of the recess 21, between internal corners 29 and 30, is typically substantially greater than three times the depth dimension of each of the undercut recess portions 14a and 15a, in an outward direction from those corners. The inner sides 32 and 33 of the projections 24 and 25 are substantially flat in a forward to rearward direction; however, they define a loop in combination with the corresponding inner and curved sides 34 and 35 of the projections 26 and 27, that loop subtending the major aerial extent of the front face, including a &#34;sweet spot&#34;. Correspondingly, all undercut sections 14a and 15a, 12a and 15a, also define, preferably, a loop. 
     It will be understood that #1-5 and #7-9 irons have the same construction, but with associated changing front face inclinations, as in a set of such irons. Accordingly, each iron of the set may have the construction as described. 
     Referring now to FIG. 5, a golf club, as for example a golf iron 110 has a head 111 and a shaft 112. The club is shown being subjected to swing weight determination, as by apparatus 113, as is known. The swing weight output display 113a may indicate the weight addition Δ needed to bring the club as manufactured up to target swing weight. The apparatus operator then selects an appropriate swing weight package or composite from the group indicated at 114, for application to the club head. The packages at 114 have different weights, typically in grams as indicated by the symbols Δ 1 , Δ 2 , Δ 3 , and Δ 4 , and the one selected is that which most closely matches the required addition weight amount Δ. Merely as illustrative, the composites corresponding to Δ 1 , Δ 2 , Δ 3 , and Δ 4  may have weights of 2, 4, 6 and 8 grams, respectively. 
     FIG. 6 is a cross section taken through a flexible package or composite 114&#39; selected from the like appearing composites in group 114. Basically, the composite itself includes a swing weight adjusting flexible layer 115, and a non-metallic flexible layer 116 adherent at 116&#39; to layer 115. Layer 116 typically carries graphics such as indicia at its side 116a which in use face rearwardly, i.e. in the direction of arrow 117 in FIGS. 6 and 8, so that the graphics are visible to the eye 130 of the club user indicated in FIG. 8. An additional flexible transparent plastic layer 118 may be applied over layer 116, to protect the graphics from marring or other damage, as could be inflicted by impact with other golf club heads such as irons carried in a golf bag. 
     Layer 116 may consist for example of a thin flexible transparent MYLAR sheet, interposed between 115 and 118; and its side facing 115 may be lightly silvered to a few microns thickness to provide a visible background to the graphics applied at 116a. The graphics may have or present the form of a medallion or trademark, providing club identity with the manufacturer. 
     Flexible layer 115 consists of strongly adhesive semi-solid material which lies intermediate layer 116 and the golf club head surface 120 seen in FIGS. 7 and 8. Accordingly, it attaches the composite or sandwich configuration package to the golf club surface 120, which may for example comprise the rear surface of an iron front wall, indicated at 120a in FIG. 8. 
     Enhanced adhesive attachment may be effected by high pressure application to the composite 114&#39;. See the plunger 122 in FIG. 7 pressing downwardly against 114&#39;, urging it against surface 120 of metal wall 120a supported on a platen 124. Wall 120a is recessed as shown to provide peripheral confinement for the composite, as at 120b and 120c. Attachment of the composite to the wall 120a may be further aided or enhanced by provision of a thin coating of urethane plastic material on and strongly adhering or bonding to wall 120a, curing that coating, and abrasively roughening the coating. The flexible adhesive layer 115 is thereby displaced against the roughened surface of the coating to lock as by bonding to interstices therein. Heat may be applied to enhance bonding. Overall bending flexibility of the package 114&#39; promotes such locking adherence thereby preventing delamination, in use. 
     It will be noted that intermediary layer 115 has or provides for selected swing weight, whereby the composites in the group 114 have different weights Δ 1  -Δ 4  for selective swing weight adjustment of different golf clubs to which they are selectively applied, i.e. so that all clubs meet target swing weight. For this purpose, the adhesive material may carry particles, such as dispersed heavy metal particles, and in such manner as to maintain layer flexibility. Typical particles include lead and tungsten. The layer 115 itself may take the form of an adhesive tape, or adhesive bearing tape, the latter being flexible and bearing dispersed weight. 
     FIG. 6 shows a protective MYLAR layer or film 128 on adhesive layer 115, and which may be peeled off just prior to pressure application of the adhesive layer 115 to the club head surface. 
     The adhesive material of layer 115 may consist of acrylic. 
     Layer 118 may consist of urethane. 
     Referring now to FIGS. 1, 2, and 3, composite means 150 is provided on the front wall 17 and located forwardly of the main recess 21 for attaining adjusted desired swing weight of the club. 
     Such composite means is typically attached to the rear side 17a of the front wall and is openly exposed to both recesses 21 and 22, the undercut recess extending about and spaced from the composite means indicated at 150. Composite 150 has the layered construction as described in reference to composite 114&#39; of FIGS. 6 and 8 above. Rear side 17a can have shallow curvature as seen in FIG. 3, the flexibility of the composite enhancing its conformation to side 17a. 
     The front wall rear side is shown as forming a shallow re-entrant recess 17a&#39; receiving and peripherally confining the composite. See also ridge 154 on the front wall rear side adjacent the composite peripheral configuration. The latter includes planar center portion 150d, and two planar wings 150e and 150f projecting in opposite directions, i.e., toward the heel and toe, respectively. The entirety of the composite 150 is effectively in or adjacent the plane of the rear side of the front wall of the head. The rearward projection of composite 150 defines an area between 25% and 75% of the cross sectional area of the recess 21, in planes parallel to the plane of the thin plate. Also, the composite area is between 20% and 65% of the area of the rear side of the front plate subtended by both recesses 21 and 22. 
     Graphics on the composite are visible via recess 21, as at 170 as seen in FIG. 1, and may take the form of indicia.