Abstract:
The present invention is directed to a non-putting iron-type golf club head having an improved striking face configuration comprising of a non-pear like shaped contour but rather a substantially symmetrical shaped one. The striking face extends to the intersection with the top face creating a top line trailing edge, wherein this edge extends from the heel to the toe and is substantially symmetrical in shape. All score lines on the striking face are symmetrical too. A theoretical vertical centerline, positioned in-line with the geometric center of the striking face and an equal distance from the toe and the heel edges. Various methods are employed to position the center of gravity of the total mass of the club head in positioned along the theoretical vertical centerline. This equates the mass of the head portion towards the heel and that of the toe as divided by the vertical centerline. The substantially symmetrical visual as viewed by the golfer at the address position provides an improved alignment possibilities and a closer to a perfect “square” club head position at address.

Description:
FIELD OF INVENTION  
         [0001]    The present invention relates generally to golf clubs. More particularly, the present invention pertains to the contour shape of the striking face of iron-type golf clubs. The present invention is particularly, but not exclusively, useful as an alignment aid when addressing a golf club in the course of planning to strike the ball.  
         BACKGROUND OF THE INVENTION  
         [0002]    The problem with conventional non-putting and iron-type golf clubs is that they are designed taking into considerations restrictions and/or limitations impose by governing bodies. These bodies mandate is to preserve the game of golf rather than to perfect club design. The most serious drawback concerns the restriction that the shaft must be connected to the club head at or near the heel of the club head. Connecting the shaft to the club head requires a type of a hosel device. To withstand the impact of the ball and, to maintain sufficient strength integrity of the club head whilst sustaining the golf swing forces, this hosel device contains a large portion of the total mass of the club head.  
           [0003]    It is important for a good club head design that whilst maintaining an overall given head weight, the center of gravity of the club head be positioned by design precisely along (higher or lower by specification) the vertical centerline through the striking face of the club head. This is important so as to ensure the minimum amount of torque, which is applied on the club head whilst striking the ball on the desired point (“sweet spot”). To offset the weight of the hosel device and position the sweet spot along the vertical centerline of the club head striking face, an increased amount of material of the club head, is positioned towards the toe of the club head. This shift of material generally causes the club striking face to be larger in the toe area and smaller in the heel area. The shape of the club head striking face, when considering its contour, has thus been described as a “pear”, in which the toe area consists of the larger section and the heel area—the smaller one. This odd shaped contour and/or curvature represents a drawback to the golfer reducing substantially the ability to align the striking face in the intended line of flight of the ball after having been struck by it. In fact the current common club head contour shape and more particularly the projected top line edge, has few or no areas, which could assist the golfer with alignment. Most edges comprise of curves rather than horizontal and/or vertical straight lines and never symmetrical. The only currently known alignment aid is thus the plurality of score lines or grooves positioned on the club striking face. The ball at address position however mostly hides these, further reducing the ability to align the club head and the striking face.  
           [0004]    Consequently there is a need for a golf club head which will provide for a better alignment of the club head prior to the club being swung whilst, at the same time, providing a substantial solid ball-impact surface so that the ball may be fully impacted within the playing ability of the golfer. It is an object of the present invention to provide methods and devices suitable for the purposes of improving the alignment of a non-putting and iron-type golf club head at address position. Such improved alignment device will therefore be greatly beneficial to the golfer in both visual and practical manners. Thus, bringing closer the intended ball flight to the actual one after striking the ball. Yet another object of the present invention is to provide methods for improving the alignment ability of a golf club head are easy to use, relatively simple to manufacture, and comparatively cost effective. The invention is particularly useful on wedges and irons designed to “attack the pin” where accuracy of the golf shot is at premium rather than the distance of flight.  
         SUMMARY OF THE INVENTION  
         [0005]    The invention provides a golf club striking face in which the top line and/or the larger portion of the striking face contour are symmetrically positioned about the vertical centerline through the club striking face. I.e., the projected topline contour and/or the visible portion of the striking face area as seen by the golfer at the address position, is symmetrical on both the heel and the toe sides of the center of the club head striking area and/or about the position of the addressed ball.  
           [0006]    Another object of this invention is to provide a golf club head where the center of gravity of such golf club head is located by design along this centerline. This design feature is imperative so as to maximize a solid ball-contact, and thus ensuring that the ball may be fully impacted within the playing ability of the golfer.  
           [0007]    The present invention comprises a golf club head having a striking area comprising of four (4) contour edges: a bottom leading edge; a top line; a heel side contour; and a toe side contour. It is possible that a portion of the total circumference (contour edge) of the striking area of such club head especially in the heel portion be hidden or blended into the hosel root where the hosel is jointed into the main section of the club head.  
           [0008]    The present invention provides for at least three (3) sections of the striking face contour to be symmetrically positioned on both sides of a vertical centerline. These are the topline, the toe contour and the upper portion of the heel contour. Based on the individual design of the club, the leading edge can be non-symmetrical so as to achieve other playability characteristics.  
           [0009]    By presenting a symmetrical topline, which is extended symmetrically to the right and to the left by portions of the toe and heel contours (depending if the club is built for a right handed or a left handed player), the golfer can better align the club head and the striking area in the direction of the intended ball flight. Such top line possibly containing at least one (1) straight and parallel section helps to position the club head in a perpendicular position at address and will encourage a “square face” making more of a solid and accurate ball contact. This unique symmetrical top line with its toe and heel extensions, accentuate the condition known to the golfer as “open face” and “closed face”. Such conditions alone even if not taking into account other swing factors, can reduce the quality of the ball contact and thus reducing the planned ball traveling distance and/or, divert the ball flight to the right or to the left of the intended ball flight path. It is also known that open and closed faces when coupled with a given swing path create an undesirable slice” and/or “hook” ball flight path.  
           [0010]    In prior art the plurality of score lines (otherwise known or referred to as grooves) are shorter as they progress higher on the striking face, whilst maintaining an offset condition towards the heel portion, which is higher by design. By making the striking face symmetrical, the areas on both sides of the club head centerline are equal (with the exception of a small area which is the root of the hosel). This offers the possibility to create score line that, are symmetrical and extend equal distances to both sides to the club head centerline covering the entire club striking face from the bottom to the top. These symmetrical score lines are an added benefit to the total visual aspect of the alignment opportunities presented to the golfer at the address position.  
           [0011]    In prior art the possibility of having vertical score lines (popular on wood-type club heads) is limited as the heel-side line will be shorter than the one on the toe-side, further reducing alignment opportunities. By making the striking face symmetrical, it offers the possibility to create one or more pairs of vertical score lines, or indeed an open or closed box design, that are symmetrical and extend equal distances to both sides to the club head centerline. These symmetrical vertical score lines are an added benefit to the total visual aspect of the alignment opportunities presented to the golfer at the address position.  
           [0012]    By simply however making the club head striking face symmetrical, the center of gravity of the club head will move towards the heel portion due to the added weight of the hosel that is located on this side. Such design is undesirable and will results in a badly performing club head. The symmetrical face does not however control that equal amount of material be positioned on both of the club head vertical centerline. Whilst maintaining only the visual aspects of the symmetrical striking face and other visual portions of the club head to the golfer at the address position, one could make use of a number of methods to shift weight from the heel section of the club head towards the toe section. Such methods include but are not limited to: shorter and lighter hosel, angled sole portion, heel side cavity, toe side cavity filled with an added secondary weight of a greater density than the one used for the main head material, a back face cavity varied in its depth creating a striking face thickness that is thicker in the toe portion than that of the heel portion, whilst maintaining an even thickness topline. Any one or more of these methods can be used simultaneously.  
           [0013]    To summarize, a singular or plurality of methods are used to equate the mass on both sides of the vertical centerline of a club head such that the club head center of gravity is located by design on this centerline. These methods however exclude the possibility of changing the symmetry of the club striking face, which remains visually symmetrical to the golfer at the address position. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:  
         [0015]    [0015]FIG. 1 is a front view of a prior art golf club head having a substantially “pear” shape striking face;  
         [0016]    [0016]FIG. 2 is a cross-section view of a prior art golf club, a portion of the club head and the hosel as seen along line  8 - 8  in FIG. 1;  
         [0017]    [0017]FIG. 3 is a top view and as seen by the golfer at the address position of a prior art golf club head having a substantially “pear” shape striking face;  
         [0018]    [0018]FIG. 4 is a top view and as seen by the golfer at the address position of an embodiment of a golf club head having a symmetrical striking face according to the present invention;  
         [0019]    [0019]FIG. 5 is a top view and as seen by the golfer at an “closed face” address position of an embodiment of a golf club head having a symmetrical striking face according to the present invention;  
         [0020]    [0020]FIG. 6 is a top view and as seen by the golfer at an “open face” address position of an embodiment of a golf club head having a symmetrical striking face according to the present invention;  
         [0021]    [0021]FIG. 7 is a back view of an embodiment of a golf club head having a symmetrical striking face according to the present invention and several potential weight shifting methods according to the present invention;  
         [0022]    [0022]FIG. 8 is a cross-section view of a portion of the club head having a symmetrical striking face according to the present invention along line  20 - 20  in FIG. 7;  
         [0023]    [0023]FIG. 9 is a front view of an embodiment of a golf club head having a symmetrical striking face according to the present invention and several potential weight shifting methods according to the present invention. It also includes a pair of equal and symmetrical vertical score lines in a form of an open top box type alignment aid.  
         [0024]    [0024]FIG. 10 is a side view of a club head being tested to locate the position of the center of gravity of the total mass of such a club head. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]    Referring initially to FIG. 1, a golf club in accordance with the prior art is shown and generally designated  1 . As shown in FIG. 1 includes a club head  1  having a hosel  2  and a striking face  10 . The striking face is further divided into the toe area  3  and the heel area  4 . Positioned on the striking face  10  are score lines  6  that extend to both sides of the vertical centerline of the club head  7 . The club head further has a sole  9  a leading edge  12  and a top line  5 .  
         [0026]    Referring now to FIG. 2, a cross section view can be seen along the vertical centerline  7  along points  8 - 8 . The club head  1  and the hosel  2  are seen in the direction from toe to heel. The striking face  10  and its top line  5  as well as the back face are all visible. Further the sole curvature can be seen. It is because the sole is curved that the club head in the address position is not “fixed” and can be manipulated in many directions by the golfer as the grip and shaft assembly is attached to it.  
         [0027]    Referring now to FIG. 3, a golf club head in accordance with the prior art is shown and generally designated  1 . This view is a top view or as generally referred to as “the address position”. As shown in FIG. 3 includes a club head  1  having a hosel  2  and a striking face  10 . The striking face is further divided into the toe area  3  and the heel area  4 . Positioned on the striking face  10  are score lines  6  that extend to both sides of the vertical centerline of the club head  7 . The club head further has a leading edge  12  and a top line  5 . As can be clearly seen the score lines are only symmetrical in the lower section of the striking face. As the score lines progress towards the upper portion of the striking area they become shorter and only visible on the toe section of the club striking face. It is further clearly seen that nothing in this view encourages and promotes any type of alignment aid. Not having any straight lines either horizontal or vertical makes “squaring up” of the club head very difficult. Only by approximation, memorizing positions and trial and error as well as very few visual parts of the score lines, which are not hidden by the presents of the ball in position along the centerline  7  and above the leading edge  12 , is it possible to align the face at the address position. None of these are positive and definite.  
         [0028]    Referring now to FIG. 4, an embodiment of a golf club head is shown, having a symmetrical striking face according to the present invention. This view similar to FIG. 3 is a top view or as generally referred to as “the address position”. The club head  1  has a hosel  2  and a symmetrical striking face  10  on both sides of the vertical centerline of the club head  7 . The portion of the striking face referred to as the toe  3  and heel  4  portions are too symmetrical on both sides of the vertical centerline of the club head  7 . The top line  5  is also symmetrical and so are the score lines  6  all the way from the first score line at the bottom to the very top of the striking face of the club head. The top line  5  may contain a straight-line portion extending an equal distance to both sides of the vertical centerline  7 . The top line  5  is extended by the contour of the toe and heel areas creating edges to the striking face. Edge  21  is the toe edge and edge  22  is the heel edge. Both these edges are too symmetrical on both sides of the vertical centerline of the club head  7 . These are some of the main improvements and features of this invention, which offer an improved alignment possibility. As shown in FIG. 5 when the club head is positioned in a “closed” position, the club face indeed appears to be “closed” and all parallel section and portion of the symmetrical face design in particular topline  5  and striking face  10 , immediately depict that the face is “out of square” or is not perpendicular to the intended flight of the ball line  21 . Similarly, as shown in FIG. 6 when the club head is positioned in an “opened” position, the club face indeed appears to be “open” and “out all parallel sections and parts of the symmetrical face design in particular topline  5  and striking face  10 , immediately depict that the face is “out of square” or is not perpendicular to the intended flight of the ball line  21 .  
         [0029]    Referring now to FIG. 7, an embodiment of a golf club head is shown, having a symmetrical striking face according to the present invention. This view shows the club head from the back and the striking face is in a vertical position. The club head  1  has a hosel  2  and a back face  9 . The top line  5  is symmetrical on both sides of the vertical centerline of the club head  7 . The top line  5  may contain a straight-line portion extending an equal distance to both sides of the vertical centerline  7 . The contours of the heel  21  and toe  22  upper sections of the striking area, extending top line  5  to both sides of the vertical centerline  7 , are symmetrical. These are some of the main improvements and features of this invention, which offer an improved alignment possibility.  
         [0030]    Referring now to yet another specific embodiment of the invention, the center of gravity  23  of the total mass of the golf club head  1  before it is assembled with the golf shaft is by design located along the vertical centerline  7 . The precise position of this center of gravity  23  can easily be located by a simple test using a simple and inexpensive tool. As shown in FIG. 10 a cylindrical solid bar  25  and a theoretical centerline  24  having a square face on one side and a cone on the other. The cone extends from the outer diameter of the bar to a small diameter of about {fraction (1/16)}″ to ⅛″. This bar  25  is positioned on a flat and horizontal surface and the club head  1  is balanced on top of the small diameter of the cone that is now facing upwards, making contact only with the striking face  10 . The contact point with the club head  1  is moved in any direction of the striking face  10  until the club head  1  is balanced and rests without any support and when the striking face  10  is perfectly horizontal. In this position the center of gravity  23  of the total mass of the golf club is said to be located along the theoretical centerline  24  of the bar  25  and can be marked on the striking face  10 . Those how are skilled in the art of club design are also aware that many golf club heads are designed today with the aid of sophisticated computer software. Such computer software is able to depict and illustrate to the designer the precise location of the center of gravity  23  of the total mass of the club head  1 , even before the club head  1  has been manufactured. The test described above can thus be used as quick confirmation that the club is indeed manufactured in accordance with the design specifications.  
         [0031]    The purpose of this test is to ensure that as per an important part of the embodiment of the invention, that the center of gravity  23  of the total mass of the golf club head  1  before it is assembled with the golf shaft is by design located along the vertical centerline  7 . In other wards it is in this totally balanced position that the theoretical centerline  24  is intersecting the vertical centerline  7  (now in a horizontal position along the striking face  10 ). Using the above test and by elementary rules of gravity, it can be deducted that if the contact between the coned bar  15  and the striking face  10  is located to the side of the centerline  7  and towards the heel of the club head  1 , more mass should be moved towards the toe portion of the club head  1 . Vies versa, if such contact point is located to the other side of the centerline  7  towards the toe of the club head, more mass should be moved towards the heel. It is an important part of the club head design that the center of gravity  23  of the club head  1  will be located along centerline  7  and as such that the centerline of the coned bar  24  and the vertical centerline  7  of the club head  1  intersect.  
         [0032]    Methods that enable the designer to “move” weight from one part of the club head to another basically fall into two (2) categories. The first method and the more common is by increasing and decreasing the amount of material matter from which the club head is made. The other method is by introducing a second material matter, which is either lighter or heavier that the matter material of which the head is made. By heavier it is understood to be of a higher density and a lighter one is understood to be of a lower density.  
         [0033]    In prior art as detailed in FIG. 3 the designer used the first method to “move” material from the heel portion of the club head towards the toe portion of the club head. This resulted in the pear shape striking face  10  and a slanted and often curved topline. This feature makes the alignment of the club head at the address position very difficult. By introducing the symmetrical face these disadvantages have been eliminated but at the same time the center of gravity  23  of the club head has shifted towards the heel where much of the mass comes from the hosel portion  2  of the club head  1 . It is therefore necessary to make use of 1 or more of the mass moving methods as described in general above. It is possible to make use of a plurality of methods and such from one or more of the categories detailed above. The first and the most obvious method is to reduce the mass of any portion of the club head located on the heel side of the centerline  7 . Such areas of the club head are but are not limited to the hosel, which could become smaller in diameter and shorter, and/or by introducing a back face cavity  14  and/or  19  as shown in the cross section view FIG. 8 along the section line  20 - 20  of FIG. 7. Another method to adjust weight and move material matter from the heel side towards the toe side is an adjustment to the sole area  9 . In prior art the sole is mainly parallel to the horizontal plane. In the embodiment of this invention as shown in FIG. 7 and FIG. 10, the sole is slanted by being shorter and thinner in the heel portion progressing and becoming longer and thicker in the toe portion. Yet another method to adjust weight and move material matter from the heel side towards the toe side is to vary the thickness of the striking area. This thickness is determined by the distance between the striking face and the back face. This variable thickness can but not necessarily be visually obvious at the address position. This can be done by creating a parallel top line extending into a variable depth cavity in the back face of the club. The second yet as obvious method of increasing weight on the toe side of the club head is to introduce higher density secondary materials. These materials are often made from high-density materials such as tungsten alloy in either a solid or a powder form. The solid secondary material in a form of a plug or a plate is mechanically secured into position sometimes but not always inside a cavity. The high-density tungsten powder is secured in position by compounding it with a small amount of a suitable epoxy. Recent developments in high-density tungsten powders make it possible to obtain overall compound densities of above ten grams per cubic centimeter (10 g/cc). Thus these compounds are ideal to pour, cast or inject into position without the need of additional securing devises. FIG. 7 shows possible positions of a secondary high-density material matter. Position  15  is a sole area location. Position  16  is a high toe back face location. Another possible location as shown in FIG. 9 is located on the striking face towards the toe section of the club head.  
         [0034]    Referring now to FIG. 9, an embodiment of a golf club head is shown, having a symmetrical striking face according to the present invention. This view is a front view or perpendicular to the striking face  10 . One pair of vertical score lines is shown. The one  17  is positioned towards the heel side of the striking face and the other  18 —towards the toe side of the striking face. Both are positioned in equal distances from the vertical centerline  7  and extend equal length in a vertical position. Per the overall symmetrical shape of the striking face  10  these identical and symmetrically positioned vertical score lines scientifically improve the visual “square feeling” and improve substantially the ability of the golfer to align the golf club head  1  at the address position. This feature of an equal pair of vertical score lines can further be extended to a plurality of pairs by having 2 or more lines on each side of the vertical center line  7 . Further, these vertical score lines could intersect one or more of the horizontal score lines and by so doing create a “rectangular box”. This box can be fully closed in all 4 sides or have the top or the bottom section removed. FIG. 9 shows such a “rectangular box” with the top (upper) section removed.  
         [0035]    While in the foregoing specification a detailed description of a specific embodiment of the invention was set forth for the purpose of illustration, it will be understood that many of the details herein given may be varied considerably by those skilled in the art without departing from the spirit and the scope of the invention.