US20050137025A1

Movatterモバイル変換

Info

Publication number: US20050137025A1
Application number: US10/958,941
Authority: US
Inventors: Robert Vito; Carmen DiMario; Thomas Falone
Original assignee: Individual
Current assignee: VITO LISA; StingFree Technologies Co
Priority date: 2001-08-27
Filing date: 2004-10-05
Publication date: 2005-06-23

Abstract

A material adapted to regulate vibration by distributing and partially dissipating vibration exerted thereon.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent application, currently pending, which is a continuation of and claims priority to U.S. patent application Ser. No. 10/659,560, currently pending, which is a divisional of and claims priority to U.S. patent application Ser. No. 09/939,319, filed on Aug. 27, 2001, now U.S. Pat. No. 6,652,398; priority to each of the above identified applications is claimed and each of the above identified applications are hereby incorporated by reference herein as if fully set forth in their entirety.

BACKGROUND

The present invention is directed to a material adapted to reduce vibration and, more specifically, to a method of making a material adapted to dissipate and evenly distribute vibrations acting on the material.

Handles of sporting equipment, bicycles, hand tools, etc. are often made of wood, metal or polymer that transmit vibrations that can make the items uncomfortable for prolonged gripping. Sporting equipment, such as bats, balls, shoe insoles and sidewalls, also transmit vibrations during the impact that commonly occurs during athletic contests. These vibrations can be problematic in that they can potentially distract the player's attention, adversely effect performance, and/or injure a portion of a player's body.

Rigid polymer materials are typically used to provide grips for tools and sports equipment. The use of rigid polymers allows users to maintain control of the equipment but is not very effective at reducing vibrations. While it is known that softer materials provide better vibration regulation characteristics, such materials do not have the necessary rigidity for incorporation into sporting equipment, hand tools, shoes or the like. This lack of rigidity allows unintended movement of the equipment encased by the soft material relative to a user's hand or body.

Prolonged or repetitive contact with excessive vibrations can injure a person. The desire to avoid such injury can result in reduced athletic performance and decreased efficiency when working with tools.

Clearly what is needed is a method of making a material adapted to regulate vibration that provides the necessary rigidity for effective vibration distribution and for a user to maintain the necessary control of the implement; that can dampen and reduce vibrational energy; and that includes a support structure that is embedded on and/or within a main vibration dissipating material.

SUMMARY

One embodiment of the present invention is directed to a golf club grip including a grip body having a generally tubular shape configured to cover a portion of a golf club shaft. The grip body is formed by a reinforced elastomer material that regulates and dissipates vibration. The grip body defines a first direction, tangential to an outer surface of the grip body, and a second direction, generally perpendicular to the outer surface of the grip body. The reinforced elastomer material includes first and second elastomer layers. A reinforcement layer disposed between and generally separating the first and second elastomer layers. The reinforcement layer including a cloth layer formed of a plurality of woven high tensile fibrous material. The plurality of woven high tensile fibrous material are connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers. The cloth layer is generally compliant only in the second direction so as to be generally non energy storing in the second direction. The high tensile fibrous material generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.

In a separate embodiment, the present invention is directed to a golf club grip including a grip body having a generally tubular shape configured to cover a portion of a golf club shaft. The grip body is formed by a reinforced elastomer material that regulates and dissipates vibration. The grip body defines a first direction, tangential to an outer surface of the grip body, and a second direction, generally perpendicular to the outer surface of the grip body. The reinforced elastomer material includes first and second elastomer layers. A reinforcement layer is disposed between and generally separates the first and second elastomer layers. The reinforcement layer includes a cloth layer formed of fiberglass. The fiberglass is connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers. The cloth layer is generally compliant only in the second direction so as to be generally non energy storing in the second direction. The fiberglass generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.

In a separate embodiment, the present invention is directed to a golf club grip including a grip body having a generally tubular shape configured to cover a portion of a golf club shaft. The grip body is formed by a reinforced elastomer material that regulates and dissipates vibration. The grip body defines a first direction, tangential to an outer surface of the grip body, and a second direction, generally perpendicular to the outer surface of the grip body. The reinforced elastomer material includes first and second elastomer layers. A reinforcement layer is disposed between and generally separates the first and second elastomer layers. The reinforcement layer is generally coextensive with the grip body. The reinforcement layer consists of a single cloth layer formed of a plurality of woven high tensile fibrous material. The plurality of woven high tensile fibrous material is connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the reinforcement layer substantially prevents the grip body from elongating in a direction parallel to a longitudinal axis of the golf club shaft when dissipating vibration. The cloth layer is generally compliant only in the second direction so as to be generally non energy storing in the second direction. The high tensile fibrous material is generally interlocked in and held in position by the first and second elastomer layers so that the high tensile fibrous material generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there are shown in the drawings embodiments which are presently preferred. It is understood, however, that the invention is not limited to the precise arrangements and instrumentality shown. In the drawings:

FIG. 1 is a cross-sectional view of a preferred embodiment of the material of the present invention illustrating a single layer vibration dissipating material with a support structure embedded therein, the material extends along a longitudinal portion of an implement and covers a proximal end thereof;

FIG. 2 is a cross-sectional view of the material ofFIG. 1 separate from any implement, padding, equipment or the like;

FIG. 2A is a cross-sectional view of a second preferred embodiment of the material of the present invention with the support structure embedded thereon and the vibration dissipating material penetrating the support structure;

FIG. 2B is cross-sectional view of a third preferred embodiment of the material of the present invention with the support structure embedded within the vibration dissipating material and the vibration dissipating material penetrating the support structure, the support structure is positioned off center within the vibration dissipating material;

FIG. 3 is a cross-sectional view of a first preferred embodiment of the support structure as taken along the lines3-3 ofFIG. 2, the support structure is formed of polymer and/or elastomer and/or fibers, either of which may contain fibers, passageways extend through the support structure allowing the vibration dissipating material to penetrate the support structure;

FIG. 4 is cross-sectional view of a second preferred embodiment of the support structure as viewed in a manner similar to that ofFIG. 3 illustrating a support structure formed by woven fibers, passageways through the woven fibers allow the support structure to be penetrated by the vibration dissipating material;

FIG. 5 is cross-sectional view of a third preferred support structure as viewed in a manner similar to that ofFIG. 3, the support structure formed by plurality of fibers, passageways past the fibers allow the vibration dissipating material to penetrate the support structure;

FIG. 6 is a side elevational view of the support structure ofFIG. 3;

FIG. 7 is perspective view of the material ofFIG. 1 configured to form a grip for a bat; and

FIG. 8 is perspective view of the material ofFIG. 1 configured to form a grip for a racquet.

FIG. 9 is an elevational view of a baseball bat having a cover in the form of a sleeve on the handle area in accordance with this invention;

FIG. 10 is an enlarged fragmental cross-sectional view of the bat and sleeve shown inFIG. 9;

FIG. 11 is a schematic diagram showing the results in the application of shock forces on a cover in accordance with this invention;

FIG. 12 is a view similar toFIG. 10 showing an alternative sleeve mounted on a different implement;

FIG. 13 is a view similar toFIGS. 10 and 12 showing still yet another form of sleeve in accordance with this invention;FIG. 14 is a cross-sectional longitudinal view showing an alternative cover in accordance with this invention mounted on a further type of implement;

FIG. 14 is a cross-sectional longitudinal view showing an alternative cover in accordance with this invention mounted on a further type of implement;

FIG. 15 is a cross-sectional end view of yet another cover in accordance with this invention;

FIG. 16 is an elevational view of a hammer incorporating an abrasive dampening handle in accordance with this invention;FIG. 17 is an elevational view showing a portion of a handlebar incorporating a vibration dampening cover in accordance with this invention;

FIG. 17 is an elevational view showing a portion of a handlebar incorporating a vibration dampening cover in accordance with this invention;

FIG. 18 is a view similar toFIG. 17 of yet another practice of this invention; and

FIGS. 19-22 are plan views of various forms of the intermediate force dissipating layer which is used in certain practices of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for convenience only and is not limiting. The words Aright,@ Aleft,@ Atop,@ and Abottom@ designate directions in the drawings to which reference is made. The words Ainwardly@ and Aoutwardly@ refer to directions toward and away from, respectively, the geometric center of the material and designated parts thereof. The term Aimplement,@ as used in the specification and in the claims, means Aany one of a baseball bat, racquet, hockey stick, softball bat, sporting equipment, firearm, or the like.@ The above terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import. Additionally, the words Aa@ and Aone@ are defined as including one or more of the referenced item unless specifically stated otherwise.

Referring toFIGS. 1-8, wherein like numerals indicate like elements throughout, there are shown preferred embodiments of a material, generally designated10, that is adapted to regulate vibration. Briefly stated, thematerial10 preferably includes a vibration dissipating material12 (preferably an elastomer layer). Thevibration dissipating material12 penetrates asupport structure17 to embed thesupport structure17 thereon (as shown inFIG. 2A) and/or therein (as shown inFIG. 2B). Thesupport structure17 is preferably semi-rigid and supports thevibration dissipating material12.

Thematerial10 of the present invention was the result of extensive research and was thoroughly tested by Villanova University's Department of Mechanical Engineering by a professor having a Ph.D. in vibratory physics. Testing of the material10 determined that the material10 can reduce the magnitude of sensible vibration by eighty (80%) percent. Thematerial10 has verified, superior vibration dissipation properties due to the embeddedsupport structure17 that is located on and/or in theelastomer12. In addition to evenly distributing vibration, thesupport structure17 contributes to the absorption of vibration and supports thevibration dissipating material12 to prevent the layer ofvibration dissipating material12 from twisting or otherwise becoming unsuitable for use as a grip or padding.

While it is preferred that the vibration dissipatingmaterial layer12 be formed by elastomer, those of ordinary skill in the art will appreciate from this disclosure that thevibration dissipating material12 can be formed by any suitable polymer without departing from the scope of the present invention. For clarity only, thevibration dissipating material12 will be often described herein as being an elastomer without any mention of the material possibly being a polymer. However, it should understood that even when thelayer12 is only described as being an elastomer, that the present invention also includes the material12 being a any suitable polymer.

Thematerial10 of the present invention can be incorporated into athletic gear, grips for sports equipment, grips for tools, and protective athletic gear. More specifically, thematerial10 can be used: to form grips for a tennis racquet, hockey sticks, golf clubs, baseball bats or the like; to form protective athletic gear for mitts, headbands, mouth guards, face protection devices, helmets, gloves, pads, hip pads, shoulder pads, chest protectors, or the like; to form seats or handle bar covers for bicycles, motorcycles, or the like; to form boots for skiing, roller blading or the like; to form footwear, such as shoe soles and inserts; to form grips for firearms, hand guns, rifles, shotguns, or the like; and to form grips for tools such as hammers, drills, circular saws, chisels or the like.

Theelastomer layer12 acts as a shock absorber by converting mechanical vibrational energy into heat energy. The embeddedsupport structure17 redirects vibrational energy and provides increased stiffness to the material10 to facilitate a user's ability to control an implement20 encased, or partially encased, by thematerial10. The incorporation of thesupport structure17 on and/or within thematerial10 allows the material10 to be formed by a single elastomer layer without the material10 being unsuitable for at least some of the above-mentioned uses. However, those of ordinary skill in the art will appreciate from this disclosure that additional layers of material can be added to any of the embodiments of the present invention disclosed below without departing from the scope of the invention.

It is preferred that the material10 have a singlecontiguous elastomer body12. Referring toFIG. 1, the support structure has first and second

major surfaces

23,25. In one embodiment, theelastomer12 extends through thesupport structure17 so that the portion of theelastomer12A contacting the first major support structure surface23 (i.e., the top of the support structure17) and the portion of theelastomer12B contacting the second major support structure surface25 (i.e., the bottom of the support structure) form the singlecontiguous elastomer body12. Elastomer material provides vibration damping by dissipating vibrational energy. Suitable elastomer materials include, but are not limited, urethane rubbers, silicone rubbers, nitrile rubbers, butyl rubbers, acrylic rubbers, natural rubbers, styrene-butadiene rubbers, and the like. In general, any suitable elastomer or polymer material can be used to form thevibration dissipating layer12.

The softness of elastomer materials can be quantified using Shore A durometer ratings. Generally speaking, the lower the durometer rating, the softer the material and the more effective a material layer is at absorbing and dissipating vibration because less force is channeled through the material. When a soft material is squeezed, an individual's fingers are imbedded in the material which increases the surface area of contact between the user's hand and creates irregularities in the outer material surface to allow a user to firmly grasp any implement20 covered, or partially covered, by the material. However, the softer the material, the less control a user has when manipulating an implement20 covered by the material. If the elastomer layer is too soft (i.e., if the elastomer layer has too low of a Shore A Durometer rating), then the implement20 may rotate unintentionally relative to a user's hand or foot. Thematerial10 of the present invention is preferably designed a Shore A durometer rating that provides an optimum balance between allowing a user to precisely manipulate and control the implement20 and effectively damping vibration during use of the implement20 depending on the activity engaged in.

It is preferable, but not necessary, that the elastomer used with the material10 have a Shore A durometer of between approximately ten (10) and approximately eighty (80). It is more preferred that theelastomer12 have a Shore A durometer of between approximately fifteen (15) and approximately forty-five (45).

Theelastomer12 is preferably used to absorb vibrational energy and to convert vibrational energy into heat energy. Theelastomer12 also provides a compliant and comfortable grip for a user to grasp (or provides a surface for a portion of a user's body, such as the under sole of a user's foot when thematerial10 is formed as a shoe insert).

In one embodiment, thematerial10 preferably has a Shore A durometer of approximately fifteen (15). In another embodiment, thematerial10 preferably has a Shore A Shore Durometer of approximately forty two (42). In yet another embodiment, thematerial10 preferably has a Shore A Durometer of approximately thirty-two (32). Of course, those of ordinary skill in the art will appreciate that the Shore A Durometer of the material10 can varied without departing from the scope of the present invention.

Referring toFIGS. 3-5, thesupport structure17 can be any one (or combination of) of a polymer, an elastomer, a plurality of fibers, a plurality of woven fibers, and a cloth. If thesupport structure17 and thelayer12 are both polymers or both elastomers, then they can be the same or different from each other without departing from the scope of the present invention. If vibration dissipating material is12 if formed of the same material as thesupport structure17, then thesupport structure17 can be made more rigid than themain layer12 by embeddingfibers14 therein. It is preferable that thesupport structure17 is generally more rigid than thevibration dissipating material12.

Referring again toFIG. 2A, in one embodiment, it is preferred that thesupport structure17 be embedded on theelastomer12, with the elastomer penetrating thesupport structure17. Thesupport structure17 being generally along a major material surface38 (i.e., thesupport structure17 is generally along the top of the material).

Thefibers14 are preferably, but not necessarily, formed of aramid fibers. Referring toFIG. 4, thefibers14 can be woven to form acloth16 that is disposed on and/or within theelastomer12. Thecloth layer16 can be formed of woven aramid fibers or other types of fiber. Thearamid fibers14 block and redirect vibrational energy that passes through theelastomer12 to facilitate the dissipation of vibrations. Thearamid fibers18 redirect vibrational energy along the length of thefibers18. Thus, when the plurality ofaramid fibers18 are woven to form thecloth16, vibrational energy emanating from the implement20 that is not absorbed or dissipated by theelastomer layer12 is redistributed evenly along thematerial10 by thecloth16 and preferably also further dissipated by thecloth16.

It is preferable that thearamid fibers18 are formed of a suitable polyamide fiber of high tensile strength with a high resistance to elongation. However, those of ordinary skill in the art will appreciate from this disclosure that any aramid fiber suitable to channel vibration can be used to form thesupport structure17 without departing from scope of the present invention. Additionally, those of ordinary skill in the art will appreciate from this disclosure that loose aramid fibers or chopped aramid fibers can be used to form thesupport structure17 without departing from the scope of the present invention. The aramid fibers may also be formed of fiberglass or the like.

When thearamid fibers18 are woven to form thecloth16, it is preferable that thecloth16 include at least some floatingaramid fibers18. That is, it is preferable that at least some of the plurality ofaramid fibers18 are able to move relative to the remainingaramid fibers18 of thecloth16. This movement of some of thearamid fibers18 relative to the remaining fibers of the cloth converts vibrational energy to heat energy.

Thematerial10 may be configured and adapted to form an insert for shoe. When thematerial10 is configured to form a shoe insert, thematerial10 is preferably adapted to extend along an inner surface of the shoe from a location proximate to a heel of the shoe to the toe of the shoe. In addition to forming a shoe insert, thematerial10 can be located along the sides of the shoe to protect the wearer's foot from lateral impact.

Thematerial10 may be configured and adapted to form agrip22 for an implement such as a bat, having ahandle24 and a proximal end26 (i.e., the end near to where the bat is normally gripped). Thematerial10 is preferably adapted to enclose a portion of thehandle24 and to enclose theproximal end26 of the bat or implement20. As best shown inFIGS. 7 and 8, it is preferable that thegrip22 be formed as a single body that completely encloses the proximal end of the implement20. Thematerial10 may be also be configured and adapted to form agrip22 for a tennis racket or similar implement20 having ahandle24 and aproximal end26.

While thegrip22 will be described below in connection with a baseball or softball bat, those of ordinary skill in the art will appreciate that thegrip22 can be used with any of the equipment, tools, or devices mentioned above without departing from the scope of the present invention.

When thegrip22 is used with a baseball or softball bat, thegrip22 preferably covers approximately seventeen (17) inches of the handle of the bat as well as covers the knob (i.e., theproximal end26 of the implement20) of the bat. The configuration of thegrip22 to extend over a significant portion of the bat length contributes to increased vibrational damping. It is preferred, but not necessary, that thegrip22 be formed as a single, contiguous, one-piece member.

Referring toFIG. 1, the baseball bat (or implement20) has ahandle24 including ahandle body28 having alongitudinal portion30 and aproximal end26. The material10 preferably encases at least some of thelongitudinal portion30 and theproximal end26 of thehandle24. Thegrip material10 can incorporate any of the above-describedsupport structures17. Thearamid fiber layer14 is preferably formed of wovenaramid fibers18.

As best shown inFIGS. 7 and 8, thepreferred grip22 is adapted for use with an implement20 having a handle and a proximal handle end. Thegrip22 includes atubular shell32 having a distalopen end34 adapted to surround a portion of the handle and a closedproximal end36 adapted to enclose the proximal end of the handle. It is preferable not necessary, that the material completely enclose theproximal end26 of the handle. Thetubular shell32 is preferably formed of the material10 which dissipates vibration.

Multiple methods can be used to produce the composite ormulti-layer material10 of the present invention. Briefly speaking, one method is to extrude thematerial10 by pulling asupport structure17 from a supply roll while placing the elastomer layer on both sides of thesupport structure17. A second method of producing thematerial10 of the present invention is to weave a fiber onto the implement20 and then to mold theelastomer12 thereover. Alternatively, a support structure can be pressure fit to an elastomer to form thematerial10. Those of ordinary skill in the art will appreciate from this disclosure that any other known manufacturing methods can be used to form thematerial10 without departing from the scope of the present invention. Any of the below described methods can be used to form amaterial10 orgrip22 having any of the above specified Shore A Durometers and incorporating any of the above-describedsupport structures17.

More specifically, one preferred method of making thematerial10 includes: providing anuncured elastomer12. A cloth layer is positioned on and/or within theuncured elastomer12. The cloth layer is formed by a plurality of wovenaramid fibers14. Theuncured elastomer12 penetrates thecloth layer16 to embed to thecloth16. Theuncured elastomer12 is at least partially cured to form thematerial10. Thecloth layer16 supports the curedelastomer12 and facilitates the distribution and dissipation of vibration by thematerial10.

It is preferable that theelastomer12 is cured so that some of the plurality of aramid fibers in thecloth layer16 are able to move relative to the remaining plurality ofaramid fibers18. It is also preferable that the material10 be configured to form a grip for a bat and/or racquet having ahandle24 and theproximal end26. Thegrip22 preferably encloses at least a portion of thehandle24 and theproximal end26.

Another aspect of the present invention is directed to a method of making agrip22 for an implement20 having ahandle24 and aproximal end26. Thegrip22 is formed by asingle layer material10 adapted to regulate vibration. The method includes providing an uncured elastomer. A plurality offibers14 are positioned on and/or within theuncured elastomer12. Theuncured elastomer12 is at least partially cured to form the single layer material embedding the plurality of fibers. Thesingle layer material10 has first and second major material surfaces. Thesingle layer material10 is positioned over at least a portion of thehandle24 and over theproximal end26 of thehandle24. The first major material surface contacts the implement20 and second major material surface of thesingle layer material10 forms a surface for a user to grasp. This method can be used to form agrip22 having any of the Shore A Durometers described above and can use any of thesupport structure17 also described above.

In another aspect, the present invention is directed to a method of making a material10 adapted to regulate vibration. The method includes providing acloth16 formed by a plurality of wovenaramid fibers14. The cloth has first and second major surfaces. Afirst elastomer layer12A is placed on the first major surface of the cloth. Asecond elastomer layer12B is placed on the secondmajor surface25 of thecloth16. The first and second elastomer layers12A,12B penetrate thecloth16 to form asingle layer elastomer12 having an embeddedcloth16 for support thereof.

In another aspect, the present invention is directed to a method of forming a material10 including providing acloth layer16. Positioning anelastomer12 substantially over thecloth layer16. Applying pressure to thecloth layer16 and theelastomer12 to embed thecloth layer16 on and/or in theelastomer12 to form thematerial10. When using this sort of pressure fit technique, those ordinary skill in the art will appreciate from this disclosure that thecloth layer16 and theelastomer12 can be placed in a mold prior to applying pressure without departing from the scope of the present invention.

The covering of the proximal end of an implement20 by thegrip22 results in reduced vibration transmission and in improved counter balancing of the distal end of the implement20 by moving the center of mass of the implement20 closer to the hand of a user (i.e., closer to the proximal end26). This facilitates the swinging of the implement20 and can improve sports performance while reducing the fatigue associated with repetitive motion.

FIGS. 9-10 illustrate another embodiment of the present invention. As shown therein a cover in the form of asleeve210 is mounted on the handle orlower portion218 of abaseball bat210.Sleeve210 is premolded so that it can be fit onto the handle portion of thebat212 in a quick and convenient manner. This can be accomplished by having thesleeve210 made of a stretchable or resilient material so that itsupper end214 would be pulled open and could be stretched to fit over theknob217 of thebat212. Alternatively, or in addition,sleeve210 may be provided with alongitudinal slit16 to permit the sleeve to be pulled at least partially open and thereby facilitate snapping thesleeve210 over thehandle218 of thebat212. The sleeve would remain mounted in place due to the tacky nature of the sleeve material and/or by the application of a suitable adhesive on the inner surface of the sleeve and/or on the outer surface ofhandle218.

A characterizing feature ofsleeve210, as illustrated inFIGS. 9-10, is that the lower end of the sleeve includes an outwardly extending peripheral knob2220.Knob220 could be a separate cap snapped onto or secured in any other manner to the main portion ofsleeve210. Alternatively,knob220 could be integral with and molded as part of thesleeve210.

In a broad practice of this invention,sleeve210 can be a single layer. The material would have the appropriate hardness and vibration dampening characteristics. The outer surface of the material would be tacky having high friction characteristics.

Alternatively, thesleeve210 could be formed from a two layer laminate where the vibration absorbing material forms the inner layer disposed against the handle, with a separate tacky outer layer made from any suitable high friction material such as a thermoplastic material with polyurethane being one example. Thus, the two layer laminate would have an inner elastomer layer which is characterized by its vibration dampening ability, while the main characteristic of the outer elastomer layer is its tackiness to provide a suitable gripping surface that would resist the tendency for the user's hand to slide off the handle. The provision of theknob220 also functions both as a stop member to minimize the tendency for the handle to slip from the user's hand and to cooperate in the vibration dampening affect.

FIG. 10 illustrates the preferred form of multilayer laminate which includes the innervibration absorbing layer222 and the outer tackygripping layer224 with anintermediate layer226 made of a stiffening material which dissipates force. If desiredlayer226 could be innermost andlayer224 could be the intermediate layer. A preferred stiffening material would be aramid fibers which could be incorporated in the material in any suitable manner as later described with respect toFIGS. 19-22. However, fiberglass or any high tensile strength fibrous material can be used as the stiffening material forming the layer. Additionally, in one embodiment, the stiffening layer is substantially embedded in or held in place by the elastomer layer(s).

FIG. 11 schematically shows what is believed to be the affect of the shock forces from vibration when the implement makes contact such as from thebat212 striking a ball.FIG. 11 shows the force vectors in accordance with a three layer laminate, such as illustrated inFIG. 10, wherein

elastomeric layers

222,224 are made of a silicone material. Theintermediate layer226 is an aramid layer made of aramid fibers. The initial shock or vibration is shown by the lateral ortransverse arrows228 on each side of thesleeve laminate210. This causes the

elastomeric layers

222,224 to be compressed along thearc230. The inclusion of theintermediate layer226 made from a force dissipating material spreads the vibration longitudinally as shown by thearrows232. The linear spread of the vibration causes a rebound effect which totally dampens the vibration.

Laboratory tests were carried out at a prominent university to evaluate various grips mounted on baseball bats. In the testing, baseball bats with various grips were suspended from the ceiling by a thin thread; this achieves almost a free boundary condition that is needed to determine the true characteristics of the bats. Two standard industrial accelerometers were mounted on a specially fabricated sleeve roughly in positions where the left hand and the right hand would grip the bat. A known force was delivered to the bat with a standard calibrated impact hammer at three positions, one corresponding to the sweet spot, the other two simulating “miss hits” located on the mid-point and shaft of the bat. The time history of the force as well as the accelerations were routed through a signal conditioning device and were connected to a data acquisition device. This was connected to a computer which was used to log the data.

Two series of tests were conducted. In the first test, a control bat (with a standard rubber grip, WORTH Bat—model #C405) was compared to identical bats with several “Sting-Free” grips representing practices of the invention. These “Sting-Free” grips were comprised of two layers of pure silicone with various types of high tensile fibrous material inserted between the two layers of silicone. The types of KEVLAR, a type of aramid fiber that has high tensile strength, used in this test were referenced as follows: “005”, “645”, “120”, “909”. Also, a bat with just a thick layer of silicone but no KEVLAR was tested. With the exception of the thick silicone (which was deemed impractical because of the excessive thickness), the “645” bat showed the best reduction in vibration magnitudes.

The second series of tests were conducted using EASTON Bats (model #BK8) with the “645” KEVLAR in different combinations with silicone layers: The first bat tested was comprised of one bottom layer of silicone with a middle layer of the “645” KEVLAR and one top layer of silicone referred to as “111”. The second bat test was comprised of two bottom layers of silicone with a middle layer of KEVLAR and one top layer of silicone referred to as “211”. The third bat tested was comprised of one bottom layer of silicone with a middle layer of KEVLAR and two top layers of silicone referred to as “112”. The “645” bat with the “111” configuration showed the best reduction in vibration magnitudes.

In order to quantify the effect of this vibration reduction, two criteria were defined: (I) the time it takes for the vibration to dissipate to an imperceptible value; and, (2) the magnitude of vibration in the range of frequencies at which the human hand is most sensitive.

The sting-free grips reduced the vibration in the baseball bats by both quantitative measures. In particular, the “645” KEVLAR in a “111” configuration was the best in vibration reduction. In the case of a baseball bat, the “645” reduced the bat's vibration in about ⅕ the time it took the control rubber grip to do so. The reduction in peak magnitude of vibration ranged from 60% to 80%, depending on the impact location and magnitude.

It was concluded that the “645” KEVLAR grip in a “111” combination reduces the magnitude of sensible vibration by 80% that is induced in a baseball bat when a player hits a ball with it. This was found to be true for a variety of impacts at different locations along the length of the bat. Hence, a person using the “Sting-Free” grips of the invention would clearly experience a considerable reduction in the sting effect (pain) when using the “Sting-free” grip than one would with a standard grip.

In view of the above tests a particularly preferred practice of the invention involves a multilayer laminate having an aramid such as KEVLAR, sandwiched between layers of pure silicone. The above indicated tests show dramatic results with this embodiment of the invention. As also indicated above, however, the laminate could comprise other combinations of layers such as a plurality of bottom layers of silicone or a plurality of top layers of silicone. other variations include a repetitive laminate assembly wherein a vibration dampening layer is innermost with a force dissipating layer against the lower vibration dampening layer and then with a second vibration dampening layer over the force dissipating layer followed by a second force dissipating layer, etc. with the final laminate layer being a gripping layer which could also be made of vibration dampening material. Among the considerations in determining which laminate should be used would be the thickness limitations and the desired vibration dampening properties.

The various layers could have different relative thicknesses. Preferably, the vibration dampening layer, such aslayer222, would be the thickest of the layers. The outermost gripping layer, however, could be of the same thickness as the vibration dampening layer, such aslayer224 shown inFIG. 10 or could be a thinner layer since the main function of the outer layer is to provide sufficient friction to assure a firm gripping action. A particularly advantageous feature of the invention where a force dissipating stiffening layer is used is that the force dissipating layer could be very thin and still achieve its intended results. Thus, the force dissipating layer would preferably be the thinnest of the layers, although it might be of generally the same thickness as the outer gripping layer. If desired the laminate could also include a plurality of vibration dampening layers (such as thin layers of gel material) and/or a plurality of stiffening force dissipating layers. Where such plural layers are used, the various layers could differ in the thickness from each other.

FIGS. 9-10 show the use of the invention where thesleeve210 is mounted over abaseball bat212 having aknob217. The same general type structure could also be used where the implement does not have a knob similar to a baseball bat knob.FIG. 12, for example, illustrates a variation of the invention wherein thesleeve210A would be mounted on thehandle218A of an implement that does not terminate in any knob. Such implement could be various types of athletic equipment, tools, etc. Thesleeve210A, however, would still have a knob2220A which would include an outergripping layer224A, an intermediateforce dissipating layer226A and an innervibration dampening layer222A. In the embodiment shown inFIG. 12, thehandle218A extends into theknob220A. Thus, theinner layer222A would have anaccommodating recess34 for receiving thehandle218A. Theinner layer222A would also be of greater thickness in the knob area as illustrated.

FIG. 13 shows a variation where thesleeve210B fits overhandle218B without thehandle218B penetrating theknob220B. As illustrated, the outergripping layer224B would be of uniform thickness both in the gripping area and in the knob. Similarly, the intermediateforce dissipating layer226B would also be of uniform thickness. The innershock absorbing layer222B, however, would completely occupy the portion of the knob inwardly of theforce dissipating layer226B since thehandle218B terminates short of the knob2220B.

FIG. 14 shows a variation of the invention where thegripping cover236 does not include a knob. As shown therein, the gripping cover would be mounted over the gripping area of ahandle238 in any suitable manner and would be held in place either by a previously applied adhesive or due to the tacky nature of the innermostvibration dampening layer240 or due to resilient characteristics of thecover236. Additionally, the cover might be formed directly on thehandle238.FIG. 16, for example, shows acover236B which is applied in the form of tape.

As shown inFIG. 14 thecover236 includes one of the laminate variations where a force dissipating layer242 is provided over the innervibration dampening layer240 with a second vibration dampening layer244 applied over force dissipating layer242 and with a final thingripping layer246 as the outermost layer. As illustrated, the twovibration dampening layers240 and244 are the thickest layers and may be of the same or differing thickness from each other. The force dissipating layer242 and outer gripping layer244 are significantly thinner.

FIG. 15 shows acover236A mounted over ahollow handle238A which is of non-circular cross-section.Handle238A may, for example, have the octagonal shape of a tennis racquet.

FIG. 16 shows afurther cover236B mounted over the handle portion of tool such ashammer248. As illustrated, thecover236B is applied in tape form and would conform to the shape of the handle portion ofhammer248. Other forms of covers could also be applied rather than using a tape. Similarly, the tape could be used as a means for applying a cover to other types of implements.

FIG. 17 illustrates acover236C mounted over the end of a handlebar, such as the handlebar of various types of cycles or any other device having a handlebar including steering wheels for vehicles and the like.FIG. 17 also illustrates a variation where thecover236C has an outer contour with finger receiving recesses252. Such recesses could also be utilized for covers of other types of implements.

FIG. 18 illustrates a variation of the invention where thecover236D is mounted to the handle portion of an implement254 with theextreme end256 of the implement being bare. This illustration is to show that the invention is intended to provide a vibration dampening gripping cover for the handle of an implement and that the cover need not extend beyond the gripping area. Thus, there could be portions of the implement on both ends of the handle without having the cover applied to those portions.

In a preferred practice of the invention, as previously discussed, a force dissipating stiffening layer is provided as an intermediate layer of a multilayer laminate where there is at least one inner layer of vibration dampening material and an outer layer of gripping material with the possibility of additional layers of vibration dampening material and force dissipating layers of various thickness. As noted the force dissipating layer could be innermost. The invention may also be practiced where the laminate includes one or more layers in addition to the gripping layer and the stiffening layer and the vibration dampening layer. Such additional layer(s) could be incorporated at any location in the laminate, depending on its intended function (e.g., an adhesive layer, a cushioning layer, etc.).

The force dissipating layer could be incorporated in the laminate in various manners.FIG. 19, for example, illustrates a force dissipatingstiffening layer258 in the form of a generally imperforate sheet.FIG. 20 illustrates aforce dissipating layer260 in the form of an open mesh sheet. This is a particularly advantageous manner of forming the force dissipating layer where it is made of KEVLAR fibers.FIG. 21 illustrates a variation where theforce dissipating layer262 is formed from a plurality of individual strips ofmaterial264 which are parallel to each other and generally identical to each other in length and thickness as well as spacing.FIG. 22 shows a variation where theforce dissipating layer266 is made ofindividual strips268 of different sizes and which could be disposed in a more random fashion regarding their orientation. Although all of thestrips268 are illustrated inFIG. 22 as being parallel, non-parallel arrangements could also be used.

The vibration dampening grip cover of this invention could be used for a wide number of implements. Examples of such implements include athletic equipment, hand tools and handlebars. For example, such athletic equipment includes bats, racquets, sticks, javelins, etc. Examples of tools include hammers, screwdrivers, shovels, rakes, brooms, wrenches, pliers, knives, handguns, air hammers, etc. Examples of handlebars include motorcycles, bicycles and various types of steering wheels.

A preferred practice of this invention is to incorporate a force dissipating layer, particularly an aramid, such as KEVLAR fiber, into a composite with at least two elastomers. One elastomer layer would function as a vibration dampening material and the other outer elastomer layer which would function as a gripping layer. The outer elastomer layer could also be a vibration dampening material. Preferably, the outer layer completely covers the composite.

There are an almost infinite number of possible uses for the composite of laminate of this invention. In accordance with the various uses the elastomer layers may have different degrees of hardness, coefficient of friction and dampening of vibration. Similarly, the thicknesses of the various layers could also vary in accordance with the intended use. Examples of ranges of hardness for the inner vibration dampening layer and the outer gripping layer (which may also be a vibration absorbing layer) are 5-70 Durometer Shore A. One of the layers may have a range of 5-20 Durometer Shore A and the other a range of 30-70 Durometer Shore A for either of these layers. The vibration dampening layer could have a hardness of less than 5, and could even be a 000 Durometer reading. The vibration dampening material could be a gel, such as a silicone gel or a gel of any other suitable material. The coefficient of friction as determined by conventional measuring techniques for the tacky and non-porous gripping layer is preferably at least 0.5 and may be in the range of 0.6-1.5. A more preferred range is 0.7-1.2 with a still more preferred range being about 0.8-1. The outer gripping layer, when also used as a vibration dampening layer, could have the same thickness as the inner layer. When used solely as a gripping layer the thickness could be generally the same as the intermediate layer, which might be about {fraction (1/20)} to ¼ of the thickness of the vibration dampening layer.

The grip cover of this invention could be used with various implements as discussed above. Thus, the handle portion of the implement could be of cylindrical shape with a uniform diameter and smooth outer surface such as the golf club handle238 shown inFIG. 12. Alternatively, the handle could taper such as the bat handle shown inFIGS. 9-10. Other illustrated geometric shapes include the octagonaltennis racquet handle238A shown inFIG. 15 or a generally oval type handle such as thehammer248 shown inFIG. 16. The invention is not limited to any particular geometric shape. In addition, the implement could have an irregular shape such as a handle bar with finger receiving depressions as shown inFIG. 17. Where the outer surface of the implement handle is of non-smooth configuration the inner layer of the cover could press against and generally conform to the outer surface of the handle and the outermost gripping layer of the cover could include its own finger receiving depressions. Alternatively, the cover may be of uniform thickness of a shape conforming to the irregularities in the outer surface of the handle.

It is recognized by those skilled in the art, that changes may be made to the above-described embodiments of the invention without departing from the broad inventive concept thereof. For example, thematerial10 may include additional layers (e.g., two or more additional layers) without departing from the scope of the present invention. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but is intended to cover all modifications which are within the spirit and scope of the invention as defined by the appended claims and/or shown in the attached drawings.

Claims

1. A golf club grip, comprising:

a grip body having a generally tubular shape configured to cover a portion of a golf club shaft, the grip body being formed by a reinforced elastomer material that regulates and dissipates vibration, the grip body defining a first direction, tangential to an outer surface of the grip body, and a second direction, generally perpendicular to the outer surface of the grip body, the reinforced elastomer material comprising:

first and second elastomer layers; and

a reinforcement layer disposed between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of a plurality of woven high tensile fibrous material, the plurality of woven high tensile fibrous material being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in the second direction so as to be generally non energy storing in the second direction, wherein the high tensile fibrous material generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.

2. The golf club grip ofclaim 1, wherein the reinforcement layer is generally coextensive with the grip body.

3. The golf club grip ofclaim 2, wherein the reinforcement layer is generally parallel to the outer surface of the grip body.

4. The golf club grip ofclaim 1, wherein the cloth layer generally separates the first and second elastomer layers and generally provides uniform coverage therebetween.

5. The golf club grip ofclaim 1, wherein the first and second elastomer layers are formed by thermoset elastomer.

6. The golf club grip ofclaim 1, wherein the reinforcement layer consists only of the cloth layer.

7. The golf club grip ofclaim 1, wherein the reinforcement layer substantially prevents the grip body from elongating in a direction parallel to a longitudinal axis of the golf club shaft when dissipating impact vibration.

8. The golf club grip ofclaim 1, wherein the cloth layer is generally interlocked in and generally held in position by the first and second elastomer layers.

9. The golf club grip ofclaim 1, wherein the cloth layer is generally embedded in and generally held in position by the first and second elastomer layers.

10. The golf club grip ofclaim 1, wherein the cloth layer is generally held in position by the first and second elastomer layers to prevent sliding movement therebetween in the first direction.

11. A golf club grip, comprising:

first and second elastomer layers; and

a reinforcement layer disposed between and generally separating the first and second elastomer layers, the reinforcement layer comprising a cloth layer formed of fiberglass, the fiberglass being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the cloth layer being generally compliant only in the second direction so as to be generally non energy storing in the second direction, wherein the fiberglass generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.

12. The golf club grip ofclaim 11, wherein the reinforcement layer is generally coextensive with the grip body.

13. The golf club grip ofclaim 12, wherein the reinforcement layer is generally parallel to the first major surface.

14. The golf club grip ofclaim 11, wherein the cloth layer generally separates the first and second elastomer layers and generally provides uniform coverage therebetween.

15. The golf club grip ofclaim 11, wherein the reinforcement layer substantially prevents the grip body from elongating in a direction parallel to a longitudinal axis of the golf club shaft when dissipating impact vibration.

16. The golf club grip ofclaim 11, wherein the reinforcement layer consists only of the cloth layer.

17. The golf club grip ofclaim 11, wherein the cloth layer is generally interlocked in and generally held in position by the first and second elastomer layers.

18. The golf club grip ofclaim 11, wherein the cloth layer is generally embedded in and generally held in position by the first and second elastomer layers.

19. The golf club grip ofclaim 1, wherein the cloth layer is generally held in position by the first and second elastomer layers to prevent sliding movement therebetween in the first direction.

20. A golf club grip, comprising:

first and second elastomer layers; and

a reinforcement layer disposed between and generally separating the first and second elastomer layers, the reinforcement layer being generally coextensive with the grip body, the reinforcement layer consisting of a single cloth layer formed of a plurality of woven high tensile fibrous material, the plurality of woven high tensile fibrous material being connected to the first and second elastomer layers generally uniformly throughout to provide substantially complete coverage between the first and second elastomer layers, the reinforcement layer substantially prevents the grip body from elongating in a direction parallel to a longitudinal axis of the golf club shaft when dissipating vibration, the cloth layer being generally compliant only in the second direction so as to be generally non energy storing in the second direction, wherein the high tensile fibrous material is generally interlocked in and held in position by the first and second elastomer layers so that the high tensile fibrous material generally distributes impact energy parallel to the first direction and into the first and second elastomer layers.