US 20040067802 A1
An improved golf tee having a ball support surface that reduces the frictional resistance of the tee when the ball is struck thus lengthening the distance a ball can be driven. A friction reducing material such as a fluorochemical or flouropolymer comprises the support surface.
1. An improved golf tee comprising:
a) a support shaft having one end for insertion into the ground;
b) a tee head carried by the other end of said support shaft, the top side of said tee head having a ball support surface formed therein; and,
c) said ball support surface comprising a low surface friction material whereby a ball mounted on said surface encounters reduced resistance when driven from the tee.
2. The golf tee of
3. The golf tee of
4. The improved tee of
5. The improved tee of
6. The improved tee of
7. The improved tee of
8. The improved tee of
9. The improved tee of
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11. The improved tee of
12. The improved tee of
13. In a golf tee, the improvement which comprises a ball support surface comprising a material selected from the group consisting of polytetrafluoroethylene polymer, copolymer, and fluorine containing polymers.
14. In a golf tee having a ball supporting head, carried by a support shaft, the improvement which comprises a head formed from a low surface tension material.
15. A process of reducing the surface friction of the support surface of a golf tee comprising the step of coating said support surface with a fluorine containing material.
 This invention relates to a golf tee specifically designed to minimize the forces of friction and shear between the golf tee and the golf ball when the ball is struck by a golf club thereby maximizing the transfer of energy and momentum from the golf club head to the ball.
 In the ever increasingly technical world the sport of golf has seen its share of innovations in the last few decades. Most of these have been aimed at either the golf ball or the golf club with a smaller number directed to the golf tee. Although a number of patents have been written for tee designs, very few have considered the golf tee as a source of improved distance and ball flight. In U.S. Pat. No. 5,683,313 and U.S. Pat. No. 5,413,330 Thomas Disco and Charles Parish disclose a Vented Golf Tee design. Venting the golf tee is done to reduce the suction between the surface of the golf tee and the golf ball upon impact with the club head. In U.S. Pat. No. 5,505,444 Edward Bouclin disclosed a flat head tee designed to reduce friction. In this patent an adhesive material must be applied to keep the ball from rolling off the tee. One might question whether the adhesive force negates any benefit from the reduced surface area.
 In U.S. Pat. No. 6,053,822 Jeffery Kolodney discloses a tee with a ring of bristles coming up to hold the ball in place. In U.S. Pat. No. 6,004,228 John Adam discloses a Vented Angular Golf Tee, another design to work on eliminating the suction between the ball and the tee. All these designs have merit in that they recognize that there are forces at play between the ball and the tee that can be reduced, altered, or re-directed. Accordingly, it is one object of my invention to minimize forces associated with the tee that act to resist the energy transferred to the ball from the golf club at impact, while at the same time keeping the end product practical to use and purchase.
 Minimizing the effect of forces associated with the tee produces longer flight distances and more initial ball spin due to the club head acting on the ball. These benefits are a primary object of the invention and are especially desirable for the long shot, where the ability to advance the ball takes precedence. In addition, the short shot where maximum backspin helps to stop the ball quickly on the green is improved. These and other benefits and objects are achieved by my invention which is described in the summary of the invention and detailed description below.
 I have surprisingly discovered that the flight distance and spin of a golf ball are increased by reducing the surface friction of the surface of the golf tee on which the golf ball rests. Thus, in one aspect, my invention is the process of reducing surface friction of the support surface of a tee by application a coating or a layer of low friction material or low surface tension material comprising, for example, a fluorochemical material or a fluorocarbon resin such as polytetrafluoroethylene, perfluoroalkoxy material or their copolymers. The entire tee may be made from a low friction material or only the head or a cap on the head may be made from low friction material.
 In another aspect, my invention comprises a tee with a support surface coating of such resins and the support surface area has been reduced to the least amount of surface area practical. My invention also comprises the method of making such a tee.
 In the drawings appended hereto and made a part of this disclosure:
FIG. 1 is a top plan view of a golf tee representing of one preferred embodiment of the present invention;
FIG. 2 is a side view of the embodiment of FIG. 1;
FIG. 3 is a perspective side view of showing a partial golf ball positioned on a prior art tee;
FIG. 4 is a sectional view of the embodiment of FIG. 2 but with a golf ball positioned on the tee; and,
FIG. 5 is a side elevation in section of preferred embodiment of the present invention showing a golf ball tee in position.
 My invention deals with three factors in improving tee performance:
 1. The surface material of the tee where the ball is intended to rest;
 2. The minimal surface area of the tee needed to contact the ball; and,
 3. The shape of contact area to minimize shear effects during a tee shot.
 The frictional forces acting when an object is resting on a surface can be represented by the equation: F=W×SA×CoF where F is the force of friction, W is the weight of the golf ball (which is a constant), SA is the surface area of contact, and CoF is the coefficient of friction of the surfaces.
 In the case of the golf ball the CoF can change depending upon the cover material used in its construction. Generally, harder balls known for their distance have lower CoF's than softer covered balls. In the case of the surface of the tee, the preferred support surface material in my invention is polytetrafluoroethylene, or PTFE, which is sold under the brand name Teflon®) (DuPont's trademark for this polymer material) as the surface of choice. This material or similar materials such as FEP (fluorinated ethylene propylene copolymer), PFA (perfluoroalkoxy), or ETFE (ethylene/tetrafluoroethylene copolymer) have the lowest coefficient of friction of generally available and usable materials. All contain fluorine in their chemistry. In addition they are known for providing non-stick surfaces.
 Terms such as fluoropolymer, fluoroplastic, fluorocarbon resin, or fluorohydrocarbon resin may be used in this specification as the preferred fluorine containing compositions are those which produce low friction surfaces or low surface tension surfaces. These composition include those compositions known as “fluorochemicals.” In general, compositions which exhibit low surface friction are within the scope of my invention. Low friction tends to be more important when the golfer is using balata or other soft covered balls that are composed of low Tg (Glass Transition Temperature) polymers that have a tendency to self adhere more easily to other surfaces than harder polymers such as those made from the ionomers sold under the brand name Surlyn® also sold by DuPont.
 Considering the surface area, most conventional or prior art tees are made more or less the same. They consist of a bowl having a diameter of approximately 10 to 13 mm. to the outer edge. In addition, this bowl shape generally has a ball conforming shape ending abruptly at the edges. From a manufacturing standpoint it is clear to see that this shape offers the golfer the greatest ease when sticking the tee in the ground and mounting a golf ball on it. However, from a frictional standpoint, the smaller the surface area of contact, the better. The smallest area of contact would be a single point, but this would make it virtually impossible for the golfer to mount the ball. In addition, the hand held ball-and-tee combination is used by many golfers for guidelines and additional force when sticking the tee in the ground and a very small point would be next to impossible to use. Obviously, any change in the shape of the tee head would have to take into consideration these things to be accepted by the typical golfer. Golfing can be frustrating enough without having to worry about mounting the golf ball on the tee.
 Referring now to FIG. 1, a top plan view of the tee 1 is shown. The minimum acceptable surface area can be achieved with three points or nobs 2 equal distance apart defined by the dotted line circle 3 in FIG. 1. It has been discovered that the minimum diameter of the center of the circle is preferably in the range of 5 to 9 mm. If the diameter is less, substantial difficulty is encountered in mounting the ball. Points defined by a larger circle can be used, but shear forces come in to play as described below. In addition, the support points 2 should be preferably short and stubby in configuration to stabilize the ball's position when using the golf ball to stick the tee into the ground. A side view of golf tee 1 with head 4 is shown in FIG. 2 with support nobs 2 having the configuration mentioned.
 In addition to frictional forces there are shear forces SF acting on a golf ball that also reduce energy transferred from a club head which strikes the ball (See FIGS. 3 & 4). The shear forces SF is the resistance to the initial movement of ball 5 direction against the edge 6 of the perimeter of the tee head. A smaller, more rounded perimeter will provide a smaller surface area thus reducing the total frictional resistance. Having a shallower resting area will help to minimize the shear force SF since less of the weight WB of the ball is beneath the edge 6. In addition, a rounded smoother edge will produce less shear force than a sharper more knife like edge. This effect may explain to some extent the longer distances and better trajectories that are seen with the balls hit by professional golfers because in a pro swing the club head contacts the ball on the upswing, and the force imparted has a lower horizontal component of the shear force SF. This force as illustrated in the center slice view of conventional ball and tee in FIG. 3 shows why an upswing hit is affected less by the shear force than a straight horizontal swing represented by FC. An embodiment of my invention to minimize these forces is illustrated in center slice view of the ball and tee in FIG. 4. It can be understood that a golfer with a swing that contacts the ball on the downward swing would tend to benefit more from this embodiment, due to the greater shear force SF imparted with this swing which would impart a vertical component to the force vector.
 In the embodiment of a tee as described above the tee would preferably be made out of pure PTFE by molding or machining, Example 9 but the expense may be unacceptable to the average player. To overcome the problem of expense and provide the advantages of reduced resistance the following examples were disclosed.
 The resting surface of a standard wooden tee was coated with a fluorosurfactant, DuPont's Zonyl, to lower the surface tension and friction of a ball resting on it.
 Observations: The low molecular weight material is easily sheared off and appears to only last 1 or 2 hits. Also, some material may be transferred to the ball and subsequently the club face which violates the following USGA rules:
 Foreign material must not be applied to the club face for the purpose of influencing the movement of the ball. Penalty is Disqualification.
 Foreign material must not be applied to a ball for the purpose of changing its playing characteristics. Penalty is Disqualification.
 A conventional wooden tee conventional according to FIG. 5 was used. The FIG. 4 tee could also be used. Surface areas were reduced so that counterpoint 111 is on a circle with a diameter similar to the diameter of the circle in FIG. 1. The edge of the tee's surface is rounded instead of sharp as shown by the surface from point 111 to edge 112. The surface was coated with a DuPont Aqueous Teflon-S Coating, such as available in the 954 series. This is a water dispersion of Dupont Teflon that requires baking to coalesce the polymer particles to a continuous film. Once the coating is applied, baking is done at 350 to 500 degrees F., for 15 to 30 minutes.
 Results: Baking a wooden tee causes the tee to become more brittle so that it does not last as long. In addition, unless the film is cast several mills thick the shear of the golf ball coming off the tee during the tee shot abrades the thin film away after only a few shots.
 A conventional wooden tee which also could be one modified as in FIG. 5 to reduce the surface area and sharp edges was coated with a DuPont Teflon S coating such as 958-303 or 958-313, a solvent based dispersion of Dupont Teflon that requires baking to coalesce the particles to a continuous film. Once the coating is applied the baking is done at 400 to 600 degrees F., for 15 to 30 minutes.
 Results: Baking continued to be+a problem with the wooden tee. The finished coating is more durable than the water based coating however, a rounded contact surface is still needed to maintain the surface integrity through several shots.
 The wooden tee as before was wrapped with a coil film crimped over the head. The coil film has been coated and baked with the DuPont Teflon dispersions used in Examples 2 and 3.
 Results: The force of the club head striking the ball also strikes the head of the tee. This force caused crimping of the coil and failure after only a few hits.
 The procedure as in Example 4 and 5 was used where the back side of the coil is treated with a pressure sensitive adhesive to adhere to the tee head.
 Results: Although this method seemed to hold up better with several tee shots possible, the abrasion of the club head to the back edge of the surface caused failure in the range of 4 to 6 hits.
 A wooden tee as in the previous examples is capped with a metal coil bent and cut to the shape shown in FIG. 5. As used herein, “coil” means a relatively thin metal sheet of greater thickness that the common thickness of metal foil. The metal coil was pre-coated with the DuPont Teflon dispersions mentioned in Examples 2 and 3 and baked at 400 to 600 degrees F. for 15 to 30 minutes to coalesce the particles into a continuous film. The shaped coil part was adhered to the wooden tee with a pressure sensitive adhesive. The coil must be of a soft metal such as aluminum, zinc, copper, or brass to prevent damage to the club head at impact.
 Results: The force of the club head striking the metal piece was enough to dislodge it after only a few shots. The metal piece in some cases was separated from the tee and launched with great velocity. Such a projectile could represent a danger to the golfer or other people on the course.
 The procedure as in Examples 6 and 7 where the metal coil is pre-coated with the DuPont Teflon dispersions mentioned in Examples 2 and 3 and baked at 400 to 600 degrees F. for 15 to 30 minutes to coalesce the particles to a continuous film was used. The cut and shaped coil part was adhered to a wooden tee using a small #4 wood screw.
 Results: This configuration worked well for several shots. However failure occurred usually due to the splintering of the wood tee around the screw again causing the metal coil and/or wood screw to be launched at a significant velocity. Such a projectile could represent a danger to the golfer or other people on the course.
 Several samples of TFPE tape backed with a pressure sensitive adhesive were obtained from Enflo. These samples differed in their thickness and ranged from 0.10 mils to 0.30 mils. Wooden tees were prepared by removing the painted surface from a conventional wooden tee. In addition some tees were shaped to reduce the surface area as in FIG. 5. The Enflo tape was cut to fit the tee's shape and applied with pressure. The adhesive was allowed to set for 24 hours.
 Results: This embodiment was the most practical and economical approach of the foregoing example. The higher mil thickness tapes had too much memory and were difficult to form on the tee head. However, even the 0.10 mil film lasted at least 15 to 20 hits. It was also noted that the thicker films tended to become compressed and deformed more readily than the thinner films.
 A cylinder of pure PTFE was turned and shaped to produce another preferred embodiment of an improved golf tee. The shape of the head conforms to the top and side views of FIG. 1 and FIG. 2.
 Result: While injection molding would be a preferred mass production technique to produce the tee of this embodiment, tooling would be necessary to make the injection mold. The cut part represents effectively the same part that would have been produced by injection molding.
 In this preferred embodiment, not only has surface friction been reduced by the use of a Teflon based material, the surface has also been reduced to the contact made by the three support prongs or nobs 2. The prongs being set at 120° provide a sure and stable resting support for the ball. The diameter of the circle around which the nubs were positioned was about 8 mm.
 A wooden tee was dipped in molten PTFE in an attempt to get a uniform coating on the head.
 Result: Although other thermoplastic materials like polyethylene or polypropylene work with this technique, the viscosity of molten PTFE was too high to effectively form an adhering coating. In addition, the high temperature needed to melt PTFE to a fluid or liquid condition were too high for a practical process.
 The tee described in Example 8 was used for comparison against a conventional wooden tee with no modifications. Several tests were conducted to determine if the tee gave an increase in performance as measured by an increase in distance with the tee shot.
 Test 1—Using a 5 wood of 21 degrees of loft ten shots were hit with range balls mounted on a standard tee and on the tee of Example 9. The 5 wood was chosen for consistency off the tee. The 5 best shots from each group were taken and measured for overall distance using a laser range finding scope with an accuracy of +/−1 yard. The results are in the following table:
 This embodiment yielded an increase in distance of 1.44%. For a 250 yard drive this could amount to 3.6 yards.
 Test 2—Using a 5 wood of 21 degrees of loft, several shots were hit with both hard covered distance balls and soft covered balata balls. The 5 wood was chosen for consistency off the tee. Both carry and carry plus roll were measured using a laser range finding scope. The results are in the following tables:
 Using Top Flite XL Distance Balls
 Using Titleist Tour Balata Balls
 In both cases whether a hard covered or soft covered ball was used an increase in carry of 2.2% was achieved. Carry and Roll were improved slightly better with the soft covered balls.
 The foregoing results demonstrate that reduction in friction and forces and resistance due to the tee shape do improve performance.
 In another embodiment the entire tee can be made of PTFE so that a cover 114 as shown in FIG. 5 is not required. FIG. 4 shows still another embodiment wherein the projections 11 and upper surface of the tee 10 are covered with a PTFE cover 12. The head 14 and shaft 13 are made of wood. Again, the entire tee can be made of PTFE eliminating the need for cover 12.
 The foregoing description of the embodiments of my invention are by way of illustration and not limitation. My invention is limited only by the scope of the claims below: