Not Applicable
1. Field of the Invention
The present invention relates to a golf club head with an insert. More specifically, the present invention relates to a putter head with a polymer insert having a face plate.
2. Description of the Related Art
Throughout the history of golf, which dates back to as early as 1457, various techniques have been used to enhance the hitting characteristics of golf club heads. Golf club heads having inserts for the striking portion have been used at least as far back as 1880's when leather face irons were manufactured in Scotland. Golfer's in the 1890's were able to purchase putters with faces composed of gutta percha. More recently, inserts composed of various materials and shapes have been put forth by the creative geniuses of the golf industry to provide golfers with better feel and control of the golf ball.
One example is an ODYSSEY® DUAL FORCE® putter having a STRONOMIC® insert that is disclosed in Magerman et al., U.S. Pat. No. 5,575,472 for a Golf Putter Head Having Face Insert And Method Of Forming The Same. The Magerman, et al. Patent discloses a putter head with a recess into which is poured or inserted a resinous material which cures and is subsequently milled to produce the putter.
Another example is an ODYSSEY® WHITE HOT® putter having an insert composed of a polyurethane material. The ODYSSEY® WHITE HOT® putter is disclosed in U.S. Pat. Ser. No. 6,238,302 for a Golf Club Head With An Insert Having Integral Tabs.
Another example is Pond, U.S. Pat. No. 5,524,331 for a Method For Manufacturing Golf Club Head With Integral Inserts that discloses a method for casting a graphite-epoxy composite insert within a recess of a face of a metal club head. The golf club head of the Pond Patent is directed at displacing the weight away from the center and increasing the moment of inertia.
Another example is Schmidt et al., U.S. Pat. No. 5,485,997, for a Golf Putter Head With Face Plate Insert Having Heightened Medial Portion, that discloses a putter head with a face plate composed of a non-metallic material such as an elastomer. The overall construction of the putter head of the Schmidt et al. Patent is directed at enlarging the sweet spot and improving the peripheral weighting.
Yet another example is found in Baker et al., U.S. Pat. No. 5,931,743 for a Putter Having Club Head With A Golf-Ball Engagement Insert And A Shaft Rearwardly Of The Insert which discloses a putter with a center shaft and an insert composed of a thermoplastic polyurethane. Another example is Jepson et al., U.S. Pat. No. 3,937,474 for a Golf Club With Polyurethane Insert, which discloses a wood having an insert on its striking face that is composed of a polyurethane formed from a tolylene diisocyanate polyether terminated prepolymer and a curing agent. The hardness of this insert varies from 40 to 75 shore D, and a Bashore Resiliometer of 17 or above. The polyurethane insert is claimed to impart additional energy to the golf ball during a golf hit.
Chen et al., U.S. Pat. No. 5,743,813 for a Golf Club Head discloses a wood composed of stainless steel with a three layer face having a first stainless steel layer, an elastic layer and a second stainless steel layer. The three-layer face does not absorb the hitting force when a golf ball is hit.
Fisher, U.S. Pat. No. 5,458,332, for a Golf Putter Head With A Cushioning Face, discloses a set of golf putters, each having an insert composed of polyurethane with a hardness in the range of 70 Shore A to about 80 Shore D. The rebound factor of each of the inserts is in the range of 12.5% to 50%, and the inserts are formulated to effect a reproducible direct linear relationship between the rebound factor and the distance of the putt.
Yet another example is McGeeney et al, European Patent Application Number 0891790 for a Multiple Density Golf Club Head And Method Of Manufacturing which discloses a putter with a central segment composed of a thermoplastic elastomer or a thermoset polymer. Possible thermoplastic elastomers include styrene co-polymers, co-polyesters, polyurethanes, polyamides, olefins and vulcanates. Possible thermoset polymers include epoxides, polyimides and polyester resins. The central segment has a minimum durometer hardness of Shore D 50. The central segment is bounded by metallic heel and to portions. However, the use of inserts is restrained in order to maintain the integrity of the game of golf.
In this regard, the Rules of Golf, established and interpreted by the United States Golf Association (“USGA”) and The Royal and Ancient Golf Club of Saint Andrews, sets forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and appendix II. A complete description of the Rules of Golf are available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for an insert for a putter, the Rules of Golf have been interpreted to establish that an insert for a putter should have a Shore A hardness greater than 87±2%, have a constant thickness, have a thickness of at least 0.125 inches, and not act like a spring.
Issues with the inserts of the prior art include complex processing, yellowing of polyurethane materials, and deformation under extended high temperatures.
The present invention provides an insert for a golf club head that is easy to manufacture, non-yellowing, and has outstanding heat deflection. The present invention is able to accomplish this by providing an insert composed of a thermoplastic polyurethane material formed from a polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymer and a 1,4 butane diol.
One aspect of the present invention is a golf club head including a club head body with an insert and a face plate. The club head body has a front face with a recess therein. The insert is disposed within the recess. The insert includes a body with an exterior surface, an interior surface and a perimeter defining the thickness of the body. The insert is composed of a thermoplastic polyurethane material formed from a polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymer and a 1,4 butane diol, wherein the insert has a Shore D hardness ranging from 50 to 65. The perimeter preferably has a plurality of integral tabs extending therefrom that engage the club head body.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
As shown in
The body 54 of the club head 52 is preferably composed of a metallic material such as stainless steel. Other metallic materials include titanium, aluminum, tungsten, zinc, magnesium, and alloys of stainless steel and tungsten. However, those skilled in the pertinent art will recognize that the body 54 may be composed of other materials without departing from the scope and spirit of the present invention. Further, the non-insert portion of the face 56 may be smooth or textured to provide a consistent or non-consistent surface with the exterior surface of the insert. Additionally, the body 54 may be specifically weighted to provide a specific center of gravity and inertial properties for the putter 50.
Referring specifically to
The putter 50 of
The putter 50 of
The putter 50 of
The putter of
The putter 50 of
The inserts 60 of
In a preferred embodiment, the insert 60 is composed of a thermoplastic polyurethane material, preferably an injection moldable thermoplastic polyurethane. The preferred polyurethane prepolymers are polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymers available from Uniroyal Chemical under the tradename ADIPRENE® LFH750, ADIPRENE® LFH749 and ADIPRENE® LFH720, which are aliphatic polyurethane prepolymers. The NCO group content of the polytetramethylene ether glycol terminated hexamethylene diisocyanate prepolymer is preferably in the range of 8.0% to 12.0%, more preferably in the range of 10.0% to 11.5%, and most preferably 11%. Alternative prepolymers include polypropylene glycol terminated hexamethylene diisocyanate prepolymer, polycaprolactone terminated hexamethylene diisocyanate prepolymer, and polyester terminated hexamethylene diisocyanate prepolymer.
The prepolymer is preferably cured with a 1,4 butane diol. However, alternative curatives include ethylene glycols, diethylene Glycols, polyethylene glycols, polypropylene glycols, propylene glycols, lower molecular weight polytetramethylene ether glycol glycols, 1,3 bis (2-hydoxyethoxy)benzene, 1,3 bis ((2-(2-hydroxyethoxy)ethoxy))benzene, 1,3 bis (((2-((2-(2-hydroxyethoxy)ethoxy)))benzene, 1,5 pentane diol, 1,6 hexane diol, resorcinol-di-(Beta-hydroxyethyl) ether, hydroquinone-di-(Beta-hydroxyethyl) ether, trimethylol Propane (TMP), and the mixtures thereof.
A colorant material, such as, for example, titanium dioxide, barium sulfate, and/or zinc oxide in a glycol or castor oil carrier, and/or other additive material(s) as are well known in the art, may be added to polyurethane precursor mixture. The amount of colorant material added is preferably in the range of about 0-10% by weight of the combined polyurethane prepolymer and curative materials, and more preferably in the range of about 2-8%.
Plasticizers such as Benzoflex and Pthalate type plasticizers (e.g., di octyl pthalate), may be added to the insert mixture to soften or lower the hardness of the final thermoplastic polyurethane material for better feel.
The Shore D hardness of the thermoplastic polyurethane material for the insert 60 preferably ranges from 40 to 70 Shore D, more preferably from 50 to 65 Shore D, and is most preferably approximately 60 Shore D.
The thickness of the insert 60 may vary depending on its application. A preferred thickness for a putter 50 is in the range of 0.125 to 0.500 inch. A preferred range of thickness is 0.188 inch to 0.200 inch. A preferred thickness is 0.198 inch. The thickness of the insert 60 is increased or decreased to influence the feel to the golfer during impact with a golf ball.
The indentation 65 of the insert 60 preferably has a depth of ranging from 0.020 inch to 0.075 inch, more preferably ranging from 0.035 inch to 0.045 inch, and most preferably having a depth of 0.040 inch. The indentation 65 is sized to accommodate the face plate 75.
The face plate 75 is preferably composed of a metal material. Such metal materials include stainless steel, steel, other steel alloys, titanium, titanium alloys, amorphous metals, aluminum, aluminum alloys, magnesium, magnesium alloys, bronze, and other like metal materials. As shown in
The face plate 75 preferably is positioned at the center of the face of the putter 20. The face plate 75 preferably covers less than 90% of the exterior surface of the insert 60, and more preferably less than 60% of the exterior surface of the insert, and most preferably covers between 25% to 50% of the exterior surface of the insert 60.
The face plate 75 is preferably co-molded with the insert 60. Alternatively, the face plate 75 is bonded within the indentation 65 of the insert 60 with an adhesive.
In a preferred embodiment, each of the plurality of tabs 100 is composed of a curved portion 130 and a straight portion 132. The straight portion 132 projects from the perimeter 120 and becomes the curved portion 130. The curved portion 132 engages with the recess edge wall 82 of the recess 58 of the club head 52. An undercut 134 is formed between the curved portion 130 and the perimeter 120 on the exterior surface 122 side of the insert 60. The undercut 134 is cut from the straight portion 132 thereby creating a straight portion 132 that does not extend along the entire width of the perimeter 120. Further, the curved portion 130 does not extend along the entire width of the perimeter 120, terminating just prior to the exterior surface 122. However, the curved portion 130 does extend further than the straight portion 132. The height “h” of the undercut 134 is preferably 0.01 inches, however it may range from 0.005 inches to 0.025 inches. Each of the plurality of tabs 100 is compressible for engagement of the insert 60 into the recess 58 of the club head 52. As described below, an adhesive is filled between the tabs 100 and into the undercuts 134 when the insert 60 is mounted in the recess 58 of the club head 52.
Tables One, Two and Three illustrate the ultraviolet light stability of the polymer insert of the present invention. Tables One, Two and Three compare the polymer of the present invention and other like polymer materials. E1 and E2 are the polymer inserts of the present invention. CE1 and CE2 are Hytrel materials. CE3 and CE4 are Estane materials. CE5 and CE6 are Hytrel materials. Table One illustrates the results prior to exposure. Table Two illustrates the results after 48 hours of exposure. Table Three illustrates the differences. DE is the combined differences.
The inserts were measured to determine the yellowing of the material after exposure to ultraviolet to simulate exposure to sunlight. The color of the inserts was determined using a HUNTER COLORIMETER model ULTRA SCAN XE and measuring the color on a L.a. b. scale. On the “L” scale, a measurement of 100 corresponds to complete white while a measurement of 0 corresponds to complete black. On the “a” scale, a negative number corresponds to a green color while a positive number corresponds to a red color. On the “b” scale, a negative number corresponds to a blue color while a positive number corresponds to a yellow color. Thus, the more positive the b measurement, the more yellow the insert.
As shown in Table Three, the insert of the present invention has almost complete ultraviolet light stability while inserts of the comparative examples vary greatly after 48 hours of exposure to ultraviolet light.
From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.
The Present Application is a continuation-in-part application U.S. Provisional Patent Application Ser. No. 60/481,733, filed on Dec. 2, 2003.
Number | Date | Country | |
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60481733 | Dec 2003 | US |