US20020037775A1

US20020037775A1 - Composite putter head

Info

Publication number: US20020037775A1
Application number: US08/989,320
Authority: US
Inventors: Regis T. Keelan
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-12-11
Filing date: 1997-12-11
Publication date: 2002-03-28
Also published as: WO1999029374A1; AU1908099A

Abstract

The golf putter head of the present invention is made of a uniform mixture of a base and a filler. The filler is chosen from materials with a high density such as metals, while the base is selected from low density materials such as plastics. The blend of the base and the filler into a uniform composite produces a putter head of unique feel and characteristics. The preferred filler for the composite is metal which adds weight and density to the total material. The metal added ranges from 50 to 95 percent by weight, depending upon the particular plastic and metal combined to achieve the desired results. The blend of metal and plastic provides a composite which is light enough to swing easily with enough weight to give a balanced feel to the putter head and furthermore, the resiliency of the material provides a good reliable response when striking a golf ball. The uniformity of the composition obviates a plastic-metal interface which can separate or mesh incorrectly leading to an inconsistent feel.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to the field of golfing equipment and more particularly to a composite golf club putter head.

2. Description of Related Art

The game of golf has seen a dramatic rise in its popularity over the last few years. This increase in golfs popularity has been accompanied by a dramatic increase in the number of golf products on the market. Advances in technology have led to improved equipment in all of the sporting equipment areas, but none more so than in golf. These technological advances have led to golfing equipment which are stronger, lighter, and more durable than the equipment used by earlier generations.

While new materials such as titanium have been used to make driver heads, there has not been as much experimentation with new materials for putter heads. This is curious, since arguably one of the most important pieces of equipment in a golfer's bag is his putter. The number of patents directed to golf club putters is a testament to this continuing search for the ultimate putter. It is said that no other club affects a golfer's score more significantly than his putter because one third to one half of an amateur's shots on a given round will be putts. Because of the individuality in putting styles and strokes, putters come in many different designs and many different shapes. Each golfer is looking for that perfect putter that has the right feel to it, in balance, weight, and “touch.” The two most important factors which influence the interaction between the ball and the putter head are the shape of the putter head and the material from which it is made.

Of primary concern to the golfer is the putter's “sweet spot.” The sweet spot denotes the area on the golf club striking surface which produces the optimum direction and distance for the golf ball. For most putter heads, the sweet spot is located at or about the center of mass of the golf club head, such that when the putter strikes the ball there is no moment or torque applied to the putter which can sap energy from the impact with the ball. Thus all of the energy is directed to the ball for a consistent reaction between the club and ball. Attempts to increase the sweet spot, thereby improving the chances of hitting a better shot, have met with varying success.

Metal is the traditional material of choice for putter heads. Thus, initial attempts to enlarge the sweet spot involved varying shapes of the putter head, and the prior art is replete with a number of various putter head shapes. Various weighting techniques have also been attempted in order to produce the optimum balance for the greatest number of putting styles. The traditional blade putter with its narrow head has been followed up by the newer mallet putter, which has greater inertia and a more solid feel to it. Several references describe putter heads with a solid, heavier member within a lighter material in an attempt to create balance and feel, while softening the impact of the putter head with the ball. See, for example, U.S. Pat. No. 5,676,606.

Other attempts to modify the putter head to soften the impact with the golf ball, thus given the golfer more control over the direction and speed of the ball, include U.S. Pat. No. 5,458,332 which describes an interchangeable solid polyurethane insert applied to the striking surface of the putter. U.S. Pat. No. 4,679,792 shows a putter head with a cavity in the forward facing surface filled with a honeycomb material to reduce the momentum imparted on the golf ball by the putter head. U.S. Pat. No. 3,843,122 describes a putter head with an internal cavity filled with a wooden block to absorb the energy from the impact with the ball, causing the ball to travel slower and with more accuracy. The goal of each of these patents is to soften the normally hard impact between a metal surface and the golf ball by adding a material to absorb some of the energy.

The disadvantages of the prior art are that the manufacture of the two discrete materials (metal with wood, honeycomb, plastic, etc.) placed adjacent to each other at an interface causes problems of its own. Different coefficients of expansion between the two materials can lead to separation and degradation, as can sudden impact or poor adhesion. Also, the transfer of forces at the interface between the two materials is difficult to predict. Over time, temperature, moisture and/or stress can cause this interface to change leading to a different feel than the original putter feel. The present invention overcomes the shortcomings of the prior art by using a unitary composite material without a plastic to metal interface to form a putter head which gives the putter an easy, balanced swing with greatly improved touch on the ball.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a golf club putter having a head comprising a composite material of uniform consistency having a metal uniformly blended into a plastic base with the metal adding density to the plastic.

The composition of metal to plastic by weight is preferably between fifty and ninety-five percent, although the percentages may vary from this range depending upon the metal chosen and the plastic chosen as well as the preference of the individual golfer. The metal is blended into the plastic base to form a uniform composite material having unique physical characteristics especially suited for a golf putter head. A non-exclusive list of plastics which may be used include ethylene vinyl acetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride. Although thermoplastics are the preferred type of plastic, thermosetting plastics may also be used. A non-exclusive list of metals which are economically practical and available include aluminum, barium, copper, iron, nickel, lead, stainless steel, and zinc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a putter typical of those used in the present invention; [0012]
FIG. 2[0013] a is an elevated view of a blade type putter head of a composite embodying the present invention;
FIG. 2[0014] b is an elevated view of a mallet type putter head of a composite embodying the present invention;
FIG. 3[0015] a is a cross-sectional view of the blade type putter of FIG. 2a; and
FIG. 3[0016] b is a cross-sectional view of the mallet type putter of FIG. 2b.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is provided to enable any person skilled in the art to make and use the invention. It sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principals of the present invention have been defined herein specifically to provide a composite putter head made from a mixture of plastic and filler in a process for the making thereof. [0017]
FIG. 1 illustrates a [0018] putter 10 typical of those embodying the present invention. The putter is comprised of a shaft 20, a grip portion 30 at a first end 40, and a putter head 50 at the opposite end 60. The shaft 20 can be made of metal or a composite material such as graphite. The grip portion 30 is typically a commercially available grip which provides a suitable surface for slip-resistant gripping of the putter. An optional hozel (not shown) may be used to connect the putter head to the putter shaft as is well known in the art.
Putter heads are generally of one of two types, a [0019] blade type 50 a and a mallet type 50 b (see FIGS. 2a and 2 b, respectively). The blade type design is the more traditional of the two designs and is generally preferred by many of the top golfing professionals today. The mallet design has the advantage of a better defined center of mass and gravity, and is preferred among the larger amateur group of golfers. The present invention is applicable to both the blade type design, the mallet type design, and the many variations thereof.
The golf putter head of the present invention is made of a uniform mixture of a base and a filler, as can be seen in FIGS. 3[0020] a and 3 b. The filler is chosen from materials with a high density such as metals, while the base is selected from low density materials such as plastics. The blend of metal and plastic provides a composite which is light enough to swing easily with enough weight to give a balanced feel to the putter head and furthermore, the resiliency of the material provides a good response when striking a golf ball. The uniformity of the composition obviates a plastic-metal interface which can separate or mesh incorrectly leading to an inconsistent feel or shot.
The preferred filler for the composite is metal which adds weight and density to the total material. The metal added ranges from 50 to 95 percent by weight, depending upon the particular plastic and metal combined to achieve the desired results. A non-exclusive list of the types of metals which can be used as fillers are as follows: aluminum, barium, copper, iron, nickel, lead, stainless steel, and zinc. A non-exclusive list of plastics which can be used in the composite include ethylene vinyl acetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride. Though thermal plastics are more appropriate, it does not preclude the use of thermal setting plastics in the present invention. The composite materials are combined to achieve a minimum hardness of Shore A85 for putters required to meet USGA approval. [0021]
The blending of these materials can be achieved with standard plastic blending equipment and manufacturers' recommended temperatures. The feed rates of the particular materials being blended must be selected based on the composition of metal to plastic and the types of metals and plastics selected, where experienced blenders can easily determine the correct rate. Injection molding is the most suitable for forming golf club heads of the present invention. However, any compression type process or method of producing solid parts is satisfactory for making weighted plastic golf club heads. It is the weighted plastic that make these clubs unique. [0022]
The composite material is generated by blending mechanically mixed dry pellets and powdered metal, and extruding the composite in a plastic extruder. The quantity of particulate filler is predetermined based on the weight of the base material and the weight of the filler so that the appropriate composition by weight can be established. The plastic-metal composition is then shaped into the putter head using either an injection molding process or suitable alternative shaping process. Once cooled and removed from the molding, the putter head can be secured to a putter shaft of choice similar to traditional putter heads. [0023]
Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein. [0024]

Claims

What is claimed is:

1. A golf club putter comprising a shaft with a grip at a first end and a putter head at a second end, said putter head comprising a composite material including a plastic base with a uniformly blended metal dispersed therein, said metal comprising at least fifty percent by weight of said composite material.

2. The golf club putter of claim 1 wherein said metal is selected from aluminum, barium, copper, iron, nickel, lead, stainless steel, and zinc.

3. The golf club putter of claim 1 wherein said plastic base is selected from ethylene vinyl acetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride.

4. A golf club putter head comprising a composite material including a plastic base with a uniformly blended metal dispersed therein, said metal comprising at least fifty percent by weight of said composite material.

5. The golf club putter head of claim 4 wherein said metal is selected from aluminum, barium, copper, iron, nickel, lead, stainless steel, and zinc.

6. The golf club putter head of claim 4 wherein said plastic base is selected from ethylene vinyl acetate, polyurethane, polyolefin, polypropylene, and polyvinylchloride.

7. The golf club putter head of claim 4 wherein a hardness of said putter head is at least Shore A85.

8. The golf club putter head of claim 4 wherein said plastic base is a thermal setting plastic.

9. The golf club putter head of claim 4 wherein a ratio of said metal filler to said plastic base is between 50 and 95 percent by weight.