Patent Application
20090325726
The most common type of practice golf tee in use today at commercial driving ranges when hitting from a mat is a hollow rubber-like tube of fixed height which extends from a circular flat base. The tube portion protrudes up through a hole in the hitting mat slightly larger than the diameter of the tube. It is held in place by a round flat base and the golf ball is placed on the round open end of the tube. When using this type tee, the golfer can only change the height of the teed ball by exchanging the tee for one with a longer or shorter tube section. This type of tee is still popular with range operators because it is inexpensive and simple. While many adjustable tees have been designed, most have not proven practical for multiple reasons, particularly complicated design, difficulty of use and poor performance, especially the inability to easily be adjusted over a wide range and retain the set height after multiple impacts. Many golfers would prefer an adjustable practice tee that allows them to simulate the multiple tee heights used when actually playing golf. Of the adjustable practice tees being marketed today, the threaded type is the only design that allows unlimited adjustment between the minimum and maximum limits of the design.
The threaded types utilize a base piece with a threaded cavity, into which a matching threaded ball holding stem or “tee” part is inserted in a nut-and-bolt fashion, allowing the center tee part to be twisted, threading it up and down in the base. One of the earliest threaded type adjustable tees is the Twistee-Tee marketed by Fiberbuilt Manufacturing Inc., a maker of golf hitting mats. It works best with their matching mat because it requires the rigid base piece to be fastened to the mat and also requires a hole or cavity under the tee to allow space for the four-inch long threaded center tee piece to be screwed or threaded down to the minimum position. While this design maximizes the adjustment range and the increased mass of the center “tee” part provides durability, it cannot be easily used with other mats and for some users the large tee does not simulate a real tee when struck.
The primary reason for the large diameter of the center part is to overcome the inherent decrease in strength caused by the external threads. Later threaded type designs use a similar but smaller and shorter threaded center stem or tee part together with a flexible matching threaded base which will fit a wide variety of existing mats. While this design has less adjustment range, it provides a more realistic hitting feel. The two piece design naturally limits the adjustment range to some fraction of the height of the base piece. Increasing the height of the base increases the adjustment range but makes the tee unacceptable for use with thin hitting mats because even in the full down position it is too tall for thinner mats which can commonly be less than one inch thick. Decreasing the height of the base piece allows for use in thin mat but limits the range of adjustment. The solution presented by the available tee makers is to offer two sizes; a taller model for thick mats and a shorter model for thin mats. The thick mat taller model has an acceptable range of adjustment but the shorter thin mat version is too tall and in the full down position is too short in the full up position for all the tee shots a golfer might wish to practice.
All the earlier threaded types have additional common design problems. The center “tee” or ball holding part has external threads which weaken its structure, causing it to be easily bent and have a tendency to not return to the original straight upright shape. It is a common mechanical practice to cut grooves into a cylindrical part in order to make it easier to bend and reduce its tendency to return to straight. The external threads also provide tear points when struck repeatedly by a club leading to early failure. The most widely marketed design sold as the GROOVE RT is now labeled “NEW & IMPROVED Stronger and More Durable”, in an effort to show that progress has been made against the inherent failure problems in the first marketed versions caused by the external thread design. The “improved” model also has two additional washer-like parts added to the original three in an effort to lessen disassembly during use indicate problems inherent in the design.
While several other adjustable practice tees have been invented, none are widely in use today because they fail to meet one or more of these requirements:
The invention provides an improvement to the existing practice golf tees in common use when hitting golf balls from mats at driving ranges, public and private indoor hitting areas, golf club fitting, testing and swing teaching stations, and when using electronic golf swing analyzers and golf simulation video games. It is not intended for use as a tee when actually playing golf on a golf course. It is a new design which overcomes the problems inherent in all of the currently available adjustable and non-adjustable practice tees.
To further show the unique advantages of the invention, the following drawings have been included:
As shown in
The configuration of a three point ball seat 20 atop a narrow smooth sided shaft 15 provides several advantages over the conventional round seat of most tees. By minimizing the surface contact between ball and tee to only three small areas, the tee has less chance of affecting the ball's launch trajectory. There is also less chance of the club making contact with the tee before impacting the ball and the decreased mass of the tee absorbs less of the club's energy. The three point shape also serves as a convenient handle by which the user turns the stem 14 to adjust it up (counterclockwise) or down (clockwise).
The base piece 12 has a circular flat flange portion 13 at the bottom and a tapered cylindrical upright portion 23 with an internal double female threaded cavity 17. There are openings at the bottom 19 and top 21 of the base and protrusions 22 on the underside of the flange to help prevent the base from turning when the stem 14 is turned for the purpose of adjustment.
The stem support opening 24 is unthreaded and of the same diameter as the stem main shaft 15. A tapered top opening 21 provides access to the stem support opening 24 and a stop for the three point ball seat 20 when the stem is in the fully down position shown in
The base 12 is made of urethane rubber with a hardness of 75 to 80 on the Shore hardness scale. The stem 14 is made of urethane rubber with a Shore 90A hardness. Both can be fabricated using a number of molding systems and procedures commonly known and used in the rubber and plastics industries. Other materials with very similar durability and elasticity might also be used with acceptable results.
The tee 10 is assembled by pressing the cylindrical lower portion 18 of the stem into the tapered top opening 21 and stem support opening 24, then twisting the stem 14 clockwise until the double male rounded threads shown in detail view of
The unique combination of shapes, material hardness and elasticity incorporated into the design allow the stem 14 to be inserted into the base during assembly without damage to either piece. That unique combination also provides that, after assembly the stem is captured in the base and cannot be removed by hand or when repeatedly struck violently with a golf club. The flat upper surface 28 and mass of the double male threads incorporated into the lower portion of the stem (see
This application claims the benefit of priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/133,329 filed on Jun. 27, 2008, which is incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61133329 | Jun 2008 | US |
