Tennis swing trainer

Abstract

A tennis swing trainer provides a tennis swing trainer target which outwardly extended on a hand held flexible shaft allows swinging engagement of a tennis racquet.

Description

I. BACKGROUND

A tennis swing trainer provides a tennis swing trainer target which outwardly extended on a hand held flexible shaft allows swinging engagement of a tennis racquet.

Sports player swing training devices provide an aid to imprint the feel and reflex of the proper swing in the sports player's mind. The feedback provided by a sports player swing training device can be important to correctly imprint the proper swing behavior in relation to a particular sports activity. The “feel” of the sports player swing training device contributes to the feedback provided to the sports player during use of the sports player swing training. With respect to tennis swing training, an important part of the feedback to the tennis player can be the “feel” of the string pattern of the tennis racquet impacting the tennis ball. Altering the “feel” of the impact characteristics between the string pattern of the tennis racquet and the target object can alter the imprint of the proper swing reflex. Understandably, if the target object of a tennis swing training device does not generate a “feel” on impact with the string pattern of the tennis racquet that is sufficiently similar to a tennis ball, then the tennis player's swing reflect can be conditioned away from, rather than toward, a swing reflex advantageous to the tennis player during actual tennis play.

Obtaining the proper “feel” in the constructional form and operational characteristics of a tennis swing trainer to correctly condition and imprint a tennis swing reflex may require utilization of a target object or target support elements which impart impact characteristics entirely unlike or which can be differentiated from the target objects utilized to make conventional baseball swing training devices, such as described by U.S. Pat. No. 6,786,841, or conventional volleyball practice devices, such as described by U.S. Pat. No. 5,755,631.

II. SUMMARY OF THE INVENTION

Accordingly, a broad object of the invention can be to provide a tennis swing trainer which provides a tennis swing trainer target which outwardly extended on a hand held flexible shaft allows swinging engagement of a tennis racquet.

A second broad object of the invention can be to provide a tennis swing trainer which provides a constructional form and operational characteristics which provides the proper “feel” to correctly condition the tennis swing of a tennis player.

A third broad object of the invention can be to provide methods of making and using a tennis swing trainer which provides the proper “feel” to correctly condition the tennis swing of a tennis player. A particular aspect of this broad object of the invention can be to provide a method of making and using particular constructional and operational forms of a tennis swing trainer target coupled to a flexible shaft which separately or in combination provide the proper “feel” to correctly condition the tennis swing of a tennis player.

Naturally, further objects of the invention are disclosed throughout other areas of the specification, drawings, photographs, and claims.

III. A BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides an illustrative example of a particular method of using an embodiment of the tennis swing trainer.

FIG. 2 provides an illustrative example of a particular method of using an embodiment of the tennis swing trainer.

FIG. 3 is a side view of a particular embodiment of the tennis swing trainer in the unflexed condition.

FIG. 4 is a handle end view of a particular embodiment of the tennis swing trainer.

FIG. 5 is a tennis swing trainer target end view of a particular embodiment of the tennis swing trainer.

FIG. 6 is a top view of a particular embodiment of the tennis swing trainer in the unflexed condition shown by unbroken object lines and broken lines illustrating the tennis swing trainer in particular flexed conditions.

IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A tennis swing trainer (1) provides a tennis swing trainer target (6) which outwardly extended on a hand held flexible shaft (5) allows swinging engagement of a tennis racquet (12).

Referring primarily to FIG. 1, a particular method of using a tennis swing trainer (1) includes a first person (2) which grips a handle (3) coupled to a first shaft end (4) of a flexible shaft (5) to outwardly extend a tennis swing trainer target (6) coupled to the second shaft end (7) of the flexible shaft (5) thereby establishing the tennis swing trainer target (6) at a first tennis swing trainer target location (8). A second person (9) grips a tennis racquet (10) by a tennis racquet handle (11) and swings the tennis racquet head (12) in a swing path (13) to engage the tennis racquet face (14) with the tennis swing trainer target (6).

Now referring primarily to FIG. 2, impact of the tennis racquet face (14) with the tennis swing trainer target (6) generates an amount of travel (15) of the tennis swing trainer target (6) consistent with the amount resilient flexure of the flexible shaft (5) and constructional form of the tennis swing trainer target (6) toward a second tennis swing trainer target location (16) as the racquet follows through in the swing path (13) to generate the resiliently flexed condition (23) of the flexible shaft (5)(see also FIG. 6). The resiliently flexed condition (23) generated in the flexible shaft (5) can return the tennis swing trainer target (6) to the first tennis swing trainer location (8). By repeating the above-described steps, the second person (9) can practice a tennis swing by serially engaging the tennis racquet face (14) with the tennis swing trainer target (6) a plurality of times.

Understandably, the first person (2) can be any person which can grip the handle (3) of the tennis swing trainer (1) and as to certain embodiments of the tennis swing trainer (1) the person can be replaced by any device which can grip the handle (3) of the tennis swing trainer (1) to establish the tennis swing trainer target (6) at the first tennis swing trainer target location (8). Also, while FIG. 1 shows the tennis swing trainer target (6) established at a particular first tennis swing target location (8) to provide forehand tennis swing training, the first tennis swing target location (8) be established at any location about the first person (2) which may aid in tennis swing training for the second person (9). The second person (9) can be any person that can grip the tennis racquet handle (11) and can swing the tennis racquet head (12) in a swing path (13) to engage the tennis racquet face (14) with the tennis swing trainer target (6).

Now referring primarily to FIG. 3 and 7, the tennis swing trainer (1) can comprise a flexible shaft (5)(the particular embodiment of the tennis swing trainer shown having a flexible cover (34) partially cut away to show the flexible shaft (5)) having a first shaft end (4) and a second shaft end (7). A handle (3) can be coupled to or about a portion of the first shaft end (4) and a tennis swing trainer target (6) can be coupled to or about a portion of the second shaft end (7)(a resilently flexible portion (35) of the flexible shaft (5) between the handle (3) and the tennis swing trainer target (6) as shown in FIG. 3). Now referring to FIG. 7, the particular embodiment of the tennis swing trainer (1) shown provides a handle (3) which couples about a length of the flexible shaft (17) proximate to the first shaft end (4). The length of the flexible shaft (17) about which the first handle part (15) couples can vary depending on the type of engagement between the surfaces of the handle (3) and the length of the flexible shaft (17). As to those particular embodiments of the tennis trainer (1) in which the length of the flexible shaft (17) inserts into a mold to further receive an amount of polymer from which the handle (3) forms, the length of the flexible shaft (17) can be between about six inches and about fourteen inches moldably coupled to handle (3). However, it is not intended that the manner by which the handle (3) couples to the flexible shaft (5) be limited to a coupling generated between a length of the flexible shaft (17) and the polymer from which the handle (3) forms in a mold. Rather, a numerous and wide variety of handle (3) materials (such as plastic, wood, metal, or the like) can be configured to couple, interfit, mate, or otherwise engage the first shaft end (4) of the flexible shaft through frictional engagement, friction welding, mated spiral threads, post and socket with engagement fixed by mechanical fasteners, or the like.

The external surface of the handle (3) can be configured in any constructional form which allows the first person (2) to grip the handle (3) and outwardly extend the tennis swing trainer (1) as above-described. Certain embodiments of the handle (3) can further comprise a a handle grip (18) and can further comprise a handle butt (19) which function to engage the grip of the first person's hand (20) to act in opposition to travel of the tennis swing trainer away from the first person (2) during use. An annular ring (21)(or other constructional form) can be provided to attach a leash (22) which engaged to the first person (2) can function to limit travel of the tennis swing trainer (1) in relation to the location of the first person (2).

The particular constructional form and operational characteristics of the flexible shaft (5) or the tennis swing trainer target (6), independently or in combination, are important in generating the proper feel upon impact of the tennis racquet face (14) with the tennis swing trainer target (6). For example, the feel of sensorially perceivable characteristics generated by impact of a tennis racquet face (14) with a tennis ball are entirely unlike the feel of sensorial perceivable characteristics generated by impact of a baseball bat with a baseball. Because tennis swing training conditions tennis swing behavior based on perceived impact characteristics between the tennis racquet face (14) and the swingingly engaged tennis swing trainer target (6), altering the perceived impact characteristics between the tennis racquet face (14) and the tennis swing trainer target (6) can alter tennis swing behavior. Importantly, if the tennis swing trainer target (6) does not generate a “feel” that is sufficiently similar to a tennis ball on impact with the tennis racquet face (14), then tennis swing behavior can be conditioned away from, rather than toward, a swing behavior advantageous to the second person (9) during actual tennis play. Obtaining the proper “feel” in the constructional form and operational characteristics of the tennis swing trainer (1) to correctly condition the behavior of a tennis swing requires utilization of a flexible shaft (5) and a tennis swing trainer target (6), which individually or in combination, provide a constructional form or operational characteristics entirely unlike or which are differentiated from those constructional forms or operational characteristics of conventional baseball swing trainer devices, such as described by U.S. Pat. No. 6,786,841, or conventional volleyball practice devices, such as described by U.S. Pat. No. 5,755,631.

Now referring to FIGS. 3 and 6, embodiments of the tennis swing trainer (1) having the proper “feel” provide a flexible shaft (5) having a resiliently flexible portion (35) with a length of between about 28 inches and about 37 inches (the resiliently flexible portion (35) not including any additional length of the flexible shaft (5) surrounded by or engaged by the handle (3) or the tennis swing trainer target (6)). The resiliently flexible portion (35) of the flexible shaft (5) can be configured to provide a particular amount of resilient flexure (23) from the longitudinal axis (24) of the flexible shaft (5) in the unflexed condition (25) which allows the tennis swing trainer target (6) to travel a distance (28) of between about two inches and about three inches (the measure can be taken at the center (36) of the tennis swing trainer target (6) as shown in FIG. 6) under a load (27) of between about 50 grams (g) and about 80 g (such load attributable in whole or in part to the tennis swing trainer target (6)). Particular embodiments of the tennis swing trainer target (6) having a weight of between about 50 g and about 80 g. Although certain embodiments of the tennis swing trainer target (6) may have greater or lesser weight.

As to the particular embodiment of the tennis swing trainer (1) shown by FIGS. 3 and 7, the flexible shaft (5) can have a substantially continuous diameter between the first shaft end (4) and the second shaft end (7) of between about one-sixteenth inch and about three eighths inch with a preferred embodiment having a diameter of about one-quarter inch. The flexible shaft can be configured from a variety of materials which provide the resilient flexure above-described with a preferred embodiment produced from E-glass reinforcements with a thermoset vinyl ester resin matrix (“E-glass rod”). A variety of configurations of E-glass rod suitable for use in the invention can be obtained from various commercial sources such as Glasforms, Inc. of San Diego Calif.

Again referring to FIGS. 3, 6 and 7, the tennis swing trainer (1) can further provide a tennis swing trainer target (6) having first target portion (29) which can be generally spherical with a diameter (36) of between about two and one-half inches and about four inches (although certain embodiments may be of lesser or greater diameter). The tennis swing trainer target (6) can further comprise a second target portion (30) or neck portion coupled to the first target portion (29) which extends from the first target portion (29) a distance about the second shaft end (7) of between about two inches to about four inches. The second target portion (30) can have a diameter of between about one inch and about one and one quarter inches. As shown by FIGS. 3 and 7, the second target portion (30) can be configured to taper from a greater diameter end (31) coupled to the first target portion (29) to a lesser diameter end (32) terminating at a distance from the first target portion (29) toward the first end of the flexible shaft (4).

To generate the proper “feel” upon impact of the racquet face (14) with the tennis swing trainer target (6), the tennis swing trainer target (6) can produced as a polymer foam (33) generated utilizing a reaction mixture including an isocyanate (which without limitation can be in the form of an isothiocyante or MDI prepolymer), a polyol (which can further include a diluent), a chain extender, a catalyst, and a blowing agent which can be introduced into a mold into which a portion of the second shaft end (7) has been inserted.

While the particular embodiment of the tennis swing trainer (1) shown in FIG. 7, incorporates an amount of methylene diphenyl diisocyanate as a MDI prepolymer in the range of about 5 percent (%) to about 20% (herein % refers to parts per hundred parts of the reaction mixture by weight) or an amount of 4,4′ methylene diphenyl diisocyanate as a MDI prepolymer in the range of about 5% to about 20% (or both in various combinations in the range of 5% to about 20%) into the reaction mixture, a numerous and wide variety of isocyanates (or isothiocyantes) or mixtures thereof can be utilized such as: 1,6-hexamethylene diisocyanate, 1,4-butylene diisocyanate, furfurylidene diisocyanate, 2,4-toluene diisocyanate, 2.6-toluene diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenylpropane diisocyanate, 4,4′-diphenyl-3,3′-dimethyl methane diisocyanate, 1,5-naphthalene diisocyanate, 1-methyl-2,4-diisocyanate-5-chlorobenzene, 2,4-diisocyanato-s-triazine, 1-methyl-2,4-diisocyanato cyclohexane, p-phenylene diisocyanate, m-phenylene diisocyanate, 1,4-naphthalene diisocyanate, dianisidine diisocyanate, bitolylene diisocyanate, 1,4-xylylene diisocyanate, 1,3-xylylene diisocyanate, bis-(4-isocyanatophenyl)methane, bis(3-methyl-4-isocyanatophenyl) methane, polymethylene polyphenyl polyisocyanates, or the like.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate an amount of hydroyxl-terminated polyether polyol having a molecular weight of at least 1,500 in the range of about 75% to about 95% (which may have the viscosity diluted with an amount of propylene carbonate in the range of about 1% to about 5%) into the reaction mixture; however, this is not intended to be limiting with respect to the numerous and wide varieties of polyols that can be included in the reaction mixture which in the alternative can include a hydroxyl-terminated backbone of a member selected from the group comprising a polyether, a polyester, a polycarbonate, a polydiene and a polycaprolactone, a hydroyl-terminated polyhydrocarbon, a hydroxyl-terminated polyformal, a fatty acid triglycerides, a hydroxyl-terminated polyesters, a hydroxymethyl-terminated polyesters, a hydroxymethyl-terminated perfluoromethylenes, a polyalkyleneether glycols, a polyalkylenearyleneether glycols, a polyalkyleneether triols, a adipic acid-ethylene glycol polyester, a poly(butylene glycol), a poly(propylene glycol) and a hydroxyl-terminated polybutadiene, separately or in various combinations or permutations.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate an amount of ethylene glycol in a range of about 2% to about 12%, or incorporate an amount of ethylene glycol in a range of about 1% to about 5% and an amount of 1,4-butanediol in a range of about 5% to about 10% as a chain extender in the reaction mixture.

The tennis swing trainer (1) shown by FIG. 7, can further incorporate an amount of gel DABCO 33 LV in the range of about 0.1% to about 3% as a catalyst in the reaction mixture; however, this is not intended to be limiting with respect to the numerous and wide varieties of catalysts that can be included in the reaction mixture and can in the alternative include a DABCO BLV catalyst, a DABCO BL-11 catalyst, a DABCO 2021 catalyst, or the like, separately or in various combinations or permutations.

Similarly, while the tennis swing trainer (1) shown by FIG. 7, can further incorporate a hydrofluorocarbon as a blowing agent (also referred to as foaming agents) such as HFC-245fa in the reaction mixture in the range of about 2% to about 12%; this is not intended to be limiting with respect to the numerous and wide varieties of blowing agents which can be included in the reaction mixture such as HFC-134a, HFC-365mfc, HFC141b, cyclopentane, or the like.

Importantly, the amounts of isothiocyanate, the polyol (along with any diluent), the chain extender, the catalyst, and the blowing agent included in the reaction mixture can be adjusted to generate a cured polymer foam tennis swing trainer target (6) configured as above-described having the proper “feel” upon impact of the racquet face (14).

Particular embodiments of the tennis swing trainer target (6) having the proper “feel” can have a range of Durometer hardness of between about 40A to about 90D, and more preferably a range of Durometer hardness of between about 50A and about 50D. As to the particular embodiment of the tennis swing trainer (1) shown in FIG. 7, and above-described, the desired “feel” can be generated utilizing a tennis swing trainer target (6) having a first target portion (29) with a diameter of between about two and one-half inches and four inches and Durometer hardness of about 40A.

Additionally embodiments of the tennis swing trainer target (6) having the proper “feel” can further provide a polymer foam (33) from a properly adjusted reaction mixture having a density of between about 0.1 grams per cubic centimeter and about 0.5 grams per cubic centimeter and more preferably a density of between about 0.15 grams per cubic centimeter and about 0.2 grams per cubic centimeter. As to the embodiment of the tennis swing trainer (1) shown in FIG. 7, the tennis swing trainer target (6) having a diameter of between about two and one-half inches to about four inches having a Durometer hardness of about 40A, can have a density of about 0.17 grams per cubic centimeter providing a suitable “feel” upon impact of the racquet face (14) with the tennis swing trainer target (6). It is intended that the term “tennis swing trainer target” at least generically encompass the numerous and varied polymer foam objects of generally spherical configuration having a diameter of between two and one-half inches and about four inches which can be coupled to the second shaft end (7) of the flexible shaft (5) having a Durometer hardness within the range of 40A to 90D and a density within the range of about 0.1 grams per cubic centimeter and about 0.5 grams per cubic centimeter, or such narrower preferred ranges of one or more parameters as above-described.

Now referring to FIGS. 3 and 7, the tennis trainer (1) can further include a flexible sleeve (34) about which a portion of the handle (3) couples and about which a portion of the tennis swing trainer target (6) couples. The flexible sleeve (34) acts to protect the flexible shaft (5) from damage upon impact and can protect the first person (2) or the second person (9) or other person from fibers that may separate from the flexible shaft. As to the embodiment of the tennis swing trainer shown in FIG. 3, the flexible shaft (5) can have a diameter of about one-quarter inch and the flexible sleeve (34) (which can be produced as a polyvinyl tube) can have an internal diameter of between about one quarter inch and about three eighths inch and an external diameter of between about three eighths inch and about one-half inch.

As can be easily understood from the foregoing, the basic concepts of the present invention may be embodied in a variety of ways. The invention involves numerous and varied embodiments of a tennis swing trainer and methods of making and using such tennis swing trainer.

As such, the particular embodiments or elements of the invention disclosed by the description or shown in the figures accompanying this application are not intended to be limiting, but rather exemplary of the numerous and varied embodiments generically encompassed by the invention or equivalents encompassed with respect to any particular element thereof. In addition, the specific description of a single embodiment or element of the invention may not explicitly describe all embodiments or elements possible; many alternatives are implicitly disclosed by the description and figures.

It should be understood that each element of an apparatus or each step of a method may be described by an apparatus term or method term. Such terms can be substituted where desired to make explicit the implicitly broad coverage to which this invention is entitled. As but one example, it should be understood that all steps of a method may be disclosed as an action, a means for taking that action, or as an element which causes that action. Similarly, each element of an apparatus may be disclosed as the physical element or the action which that physical element facilitates. As but one example, the disclosure of an “tennis swing trainer” should be understood to encompass disclosure of the act of “tennis swing training”—whether explicitly discussed or not—and, conversely, were there effectively disclosure of the act of “tennis swing training”, such a disclosure should be understood to encompass disclosure of a “tennis swing trainer” and even a “means for tennis swing training.” Such alternative terms for each element or step are to be understood to be explicitly included in the description.

In addition, as to each term used it should be understood that unless its utilization in this application is inconsistent with such interpretation, common dictionary definitions should be understood to included in the description for each term as contained in the Random House Webster's Unabridged Dictionary, second edition, each definition hereby incorporated by reference.

Thus, the applicant(s) should be understood to claim at least: i) each of the tennis swing trainers herein disclosed and described, ii) the related methods disclosed and described, iii) similar, equivalent, and even implicit variations of each of these devices and methods, iv) those alternative embodiments which accomplish each of the functions shown, disclosed, or described, v) those alternative designs and methods which accomplish each of the functions shown as are implicit to accomplish that which is disclosed and described, vi) each feature, component, and step shown as separate and independent inventions, vii) the applications enhanced by the various systems or components disclosed, viii) the resulting products produced by such systems or components, ix) methods and apparatuses substantially as described hereinbefore and with reference to any of the accompanying examples, x) the various combinations and permutations of each of the previous elements disclosed.

The claims set forth in this specification are hereby incorporated by reference as part of this detailed description of the invention, and the applicant expressly reserves the right to use all of or a portion of such incorporated content of such claims as additional description to support any of or all of the claims or any element or component thereof, and the applicant further expressly reserves the right to move any portion of or all of the incorporated content of such claims or any element or component thereof from the description into the claims or vice-versa as necessary to define the matter for which protection is sought by this application or by any subsequent continuation, division, or continuation-in-part application thereof, or to obtain any benefit of, reduction in fees pursuant to, or to comply with the patent laws, rules, or regulations of any country or treaty, and such content incorporated by reference shall survive during the entire pendency of this application including any subsequent continuation, division, or continuation-in-part application thereof or any reissue or extension thereon.

The claims set forth below are intended describe the metes and bounds of a limited number of the preferred embodiments of the invention and are not to be construed as the broadest embodiment of the invention or a complete listing of embodiments of the invention that may be claimed. The applicant does not waive any right to develop further claims based upon the description set forth above as a part of any continuation, division, or continuation-in-part, or similar application.

Claims

1. A tennis swing trainer, comprising:

a. a flexible shaft having a first shaft end and a second shaft end;

b. a handle coupled to said first shaft end; and

c. a tennis swing trainer target coupled to said second shaft end.

2. A tennis swing trainer as described in claim 1, wherein said flexible shaft has a substantially continuous diameter between said first shaft end and said second shaft end of between about one-sixteenth inch and about three eighths inch.

3. A tennis swing trainer as described in claim 2, wherein said flexible shaft has a substantially continuous diameter between said first shaft end and said second shaft end of about one quarter inch.

4. A tennis swing trainer as described in claim 2, wherein said flexible shaft between said first shaft end and said second shaft end has a length of between about thirty six inches and about sixty inches.

5. A tennis swing trainer as described in claim 4, wherein said flexible shaft between said first shaft end and said second shaft end has a length of between about 28 inches and about 37 inches.

6. A tennis swing trainer as described in claim 4, wherein said flexible shaft in response to a tennis racquet impact on said tennis swing trainer target resiliently flexes.

7. A tennis swing trainer as described in claim 6, wherein said flexible shaft has a length of between 28 inches and about 37 inches, and wherein said flexible shaft flexes allows said tennis swing trainer target to travel a distance of between about 2 inches to about 3 inches from the longitudinal axis of said flexible shaft in the unflexed condition under a load of between about 50 grams and about 80 grams.

8. A tennis swing trainer as described in claim 7, wherein said flexible shaft comprises a material selected from the group consisting of a fiberglass, an E-glass-vinyl ester resin composite, and nylon.

9. A tennis swing trainer as described in claim 6, wherein said tennis swing trainer target has a substantially spherical first portion comprises having a diameter of between about two and one-half inches and about four inches.

10. A tennis swing trainer as described in claim 9, wherein said tennis swing trainer target comprises a substantially round tennis swing target having a diameter of about one and one quarter inch.

11. A tennis swing trainer as described in claim 10, wherein said tennis swing trainer target comprises an amount of polymer foam.

12. A tennis swing trainer as described in claim 11, wherein said polymer foam is derived from a reaction mixture comprising:

a. an isocyanate;

b. a polyol;

c. a catalyst; and

d. a blowing agent.

13. A tennis swing trainer as described in claim 12, wherein said isocyanate is selected from the group consisting of an MDI prepolymer of methylene dipheyl diisocyanate or MDI prepolymer of 4,4′ methylene diphenyl diisocyanate, or mixture thereof.

14. A tennis swing trainer as described in claim 13, wherein said MDI prepolymer comprises between about 5% and about 20% of said reaction mixture.

15. A tennis swing trainer as described in claim 14, wherein said polyol comprises high molecular weight polyether polyol of between about 75% and about 95% of said reaction mixture.

16. A tennis swing trainer as described in claim 15, wherein said catalyst comprises a DABCO 33 LV catalyst of between about 0.1% and about 3% of said reaction mixture.

17. A tennis swing trainer as described in claim 16, wherein said blowing agent comprises a hydrofluorocarbon blowing agent of between about 2% and about 12%.

18. A tennis swing trainer as described in claim 17, further comprising a chain extender, wherein said chain extender comprises an amount of ethylene glycol of about 2% to about 12%.

19. A tennis swing trainer as described in claim 18, wherein said chain extender comprises an amount of ethylene glycol in a range of about 1% to about 5% and an amount of 1,4-butanediol in a range of about 5% to about 10%

20. A tennis swing trainer as described in claim 11, wherein said amount of polymer foam has a Durometer hardness of between about 40A and about 90D.

21. A tennis swing trainer as described in claim 20, wherein said amount of polymer foam has a Durometer hardness of between about 50A and about 50D.

22. A tennis swing trainer as described in claim 21, wherein said amount of polymer foam has a Durometer hardness of about 40A.

23. A tennis swing trainer as described in claim 20, wherein said amount of polymer foam has a density of between about 0.1 grams per cubic centimeter and about 0.5 grams per cubic centimeter.

24. A tennis swing trainer as described in claim 21, wherein said amount of polymer foam has a density of between about 0.15 grams per cubic centimeter and about 0.2 grams per cubic centimeter.

25. A tennis swing trainer as described in claim 22, wherein said amount of polymer foam has a density of about 0.17 grams per cubic centimeter.

26. A tennis swing trainer as described in claim 10, wherein said tennis swing trainer target further comprises a neck portion which extends from said tennis swing trainer target a distance about said second shaft end.

27. A tennis swing trainer as described in claim 26, wherein said neck portion extends from said tennis swing trainer target a distance of between about two inches to about six inches

28. A tennis swing trainer as described in claim 27, wherein said neck portion has a diameter of between about three quarters inches and about one and one quarter inches.

29. A tennis swing trainer as described in claim 5, further comprising a flexible sleeve disposed about said flexible shaft.

30. (canceled)