US20020198071A1

US20020198071A1 - Ball bat

Info

Publication number: US20020198071A1
Application number: US09/120,273
Authority: US
Inventors: Michael L. Snow
Original assignee: Miken Composites Co LLC
Current assignee: Miken Sports LLC
Priority date: 1998-07-22
Filing date: 1998-07-22
Publication date: 2002-12-26

Abstract

A ball bat having a body comprised of resin impregnated with five carbon and glass fiber socks, the body having a barrel, a taper portion and a handle portion, and a central cavity extending the length of the body. Additionally, an aluminum sleeve is press-fit along the inside of the barrel, and a flexible end cap is mounted within the end of the barrel.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to athletic bats, and more specifically to a softball bat comprised of fiber-impregnated resin for improved hitting distance and reduced vibration.

2. Description of the Related Art

Traditional athletic bats are comprised of wood or metal, which are expensive and consume valuable natural resources. A disadvantage of wood bats is that they frequently break during use and it is exceedingly difficult to design such bats for consistent performance, given their natural material. Metal bats, while more durable, have the tendency to transmit vibration down the shaft to the hands of the user, making hitting a ball an unpleasant experience.

Composite bats and related sporting goods are well known in the related art. U.S. Pat. No. 4,546,976 which issued to T. N. Jones on Oct. 15, 1985, discloses a reinforced plastic bat with a separate handle section that is softer than the hitting section. Similarly, U.S. Pat. No. 4,569,521 which issued to A. W. Mueller on Feb. 11, 1986, discloses a composite bat having a tapered aluminum spar encased in polyurethane foam in order to provide exceptional stiffness while providing freedom from excessive vibrations.

Sports articles comprised of fiber-resin composites are also well known in the related art. One such invention, disclosed in U.S. Pat. No. 4,836,545, teaches a two-piece metallic and composite golf shaft. This invention comprises a metallic tip that telescopingly fits into an upper composite section comprised of high-strength fibers such as carbon-graphite. The two pieces are bonded together with high-strength epoxy adhesive.

U.S. Pat. No. 4,848,745 which issued to Bohannon et al. on Jul. 18, 1989, discloses a fiber-reinforced article such as a filament-wound bat or bowling pin formed from a thermoplastic resin. The article comprises at least three layers of fiber reinforcement sheets, the fibers comprised of material such as glass or carbon fiber. Each layer comprises fibers that either: circumferentially, longitudinally or helically extend in relation to the article.

U.S. Pat. No. 4,931,247 which issued to C. Yeh on Jun. 5, 1990, discloses a fabrication method of a hollow racket made of carbon fiber. During this process, a hollow bat is made by coupling the mounting of a fiber sleeve tube with the cutting of fiber-woven board. Additionally, adhesive agents are filled into the bat body and the segments of an air-blowing tube are adhered to the interior wall of the bat body, where the air is expelled during heating, thereby preventing cracking of the bat.

U.S. Pat. No., 5,409,214 which issued to D. C. Cook on Apr. 235, 1995, discloses a baseball bat having a handle and a hitting portion comprised of wood. The handle may be made of either metal or fibrous composites. Additionally, U.S. Pat. No. 5,496,027 which issued to Christian et al. on Mar. 5, 1996, discloses a reinforced hockey stick blade and method of making same. The blade is constructed of resin impregnated with a plurality of reinforcement fibers, and may be placed onto the shaft of a hockey stick.

U.S. Pat. No. 5,593,158 which issued to Filice et al. on Jan. 14, 1997, discloses a shock-attenuating ball bat having a handle that extends into a taper portion and is nested within the barrel, the handle and the barrel separated by an elastomeric isolation union, thereby reducing shock transmitted from the barrel when a batter strikes a ball. The handle and/or the barrel may be comprised of fiber-impregnated resin.

Additionally, U.S. Pat. No. 5,624,115 which issued to C. S. Baum on Apr. 29, 1997 discloses a composite bat with a cavitated core. The bat has a cellulose outer layer covering a layer of fiber-reinforced resin, which in turn surrounds a cavitated core that may also contain foam.

U.S. Pat. No. 5,722,908 which issued to Feeney et al. on Mar. 3, 1998, discloses a composite bat with a metal barrel, and a method of fabricating same. The bat has a frame having a recess and fabricated of a composite material of fibers in a matrix binder. A metal sleeve is inserted over the recess of the frame, which forms a hitting surface.

U.S. Pat. No. 5,743,811 which issued to G. M. Bird on Apr. 28, 1998, discloses a lightweight golf shaft having an inner and outer layer, each composed of graphite fiber and cured epoxy resin. A middle layer is composed of two foam half-forms or a single foam full form, thereby making the shaft lighter than conventional shafts. A method for making this shaft is also disclosed.

French Patent No. 2,462,266 which issued to Technique du Verre Tisse and was published on Feb. 13, 1981, discloses a laminated racquet shaft reinforced with parallel and crossed filaments lain up in separate layers to maintain alignment of the shaft. These filaments may be constructed of glass, boron, carbon, silica or aromatic polyamide. Additionally, French Patent No. 2,560,551 which issued to M. Verna and was published on Sep. 6, 1985 discloses a method of making reinforced plastic hollow articles by wrapping plain or resin-impregnated fibers about a multi-piece mandrel and modifying the resultant form by means of a press to obtain a taut profile with tight radial packing of the layers of fibers.

Japanese Patent No. 3,247,365 which issued to Mistubishi Rayon K. K. and was published on Nov. 5, 1991, discloses a composite bat comprising a foam core material covered by a back up pipe which is in turn covered by fiber-reinforced plastic. Finally, Japanese Patent No. 564,671 which issued to Mizuno Corp. and was published on Mar. 19, 1993, discloses a fiber-reinforced plastic bat and method of making same. An outer shell member is formed on a core which is given the shape of a bat when reinforced fiber and thermoplastic resin fiber is wound about the shaft. The thermoplastic resin fiber is melted by heat and forms a matrix, thereby impregnating the reinforced fiber therein.

None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a ball bat solving the aforementioned problems is desired.

SUMMARY OF THE INVENTION

The present invention provides a bat having a body with a hollow central cavity and having a barrel, a taper portion and a handle. The body is comprised of resin impregnated with multiple (e.g., five) braid-woven socks, the socks being constructed of carbon fiber and glass fiber, some of the socks extending the length of the body, while others of the socks extend the length of the barrel. This particular composition allows a slight deformation of the body, thereby creating a trampoline or springboard effect, adding to the velocity of a hit ball.

Additionally, an aluminum sleeve is press-fit inside the barrel in order to dissipate the kinetic energy when the ball impacts the bat, energy which would otherwise be transmitted down the shaft to sting the batter's hands. Additionally, a flexible end cap is present on the end of the barrel to properly weight the bat, and to further aid in the deformation of the body, thereby increasing the trampoline effect of the bat.

Accordingly, it is a principal object of the invention to provide a fiber-impregnated resin ball bat having the necessary strength to withstand the impact forces of a projectile, while providing a trampoline or springboard effect to for added velocity of the projectile.

It is another object of the invention to provide a ball bat that effectively dissipates the kinetic energy generated by a collision with a ball, without reducing the effectiveness of the bat.

It is a further object of the invention to provide a resin impregnated bat that may be easily manufactured and marketed.

It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.

These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a ball bat according to the present invention. [0024]
FIG. 2 is a longitudinal sectional view of the present invention, with a portion of the aluminum sleeve broken away and the end cap exploded away. [0025]
FIG. 3 is an enlarged scale section view of the present invention drawn along lines [0026] 3-3 of FIG. 1.
FIG. 4 is a plan view of the fiber socks of the present invention. [0027]
Similar reference characters denote corresponding features consistently throughout the attached drawings.[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings wherein like numerals represent like elements, FIGS. 1 and 2 show a [0029] bat 10 according to the preferred embodiment of the present invention. While a softball bat 10 is shown as the preferred embodiment, the present invention is not limited to softball bats and extends to similar articles such as baseball bats, drum sticks, billy clubs, walking sticks, cricket bats, field hockey sticks, furniture legs and the like.
The [0030] bat 10 consists of a body 12 having a hollow inner cavity 13, and is radially symmetrical about a center axis, the body further having a barrel 14, a taper portion 16, and a handle portion 18. The barrel is configured to receive an end cap 19 and becomes progressively narrower from the taper portion 16 through the handle portion 18, which terminates in a knob end 20 integral to the handle portion. The knob end 20 functions to ensure that the batter's hands stay on the bat 10 during a swing.
While many prior art bats have knob ends that are either screwed on or welded on, the present invention has an [0031] integral knob end 20, greatly reducing the possibility of the knob falling off the handle portion 18, which would otherwise render the bat 10 unusable under the “Official Rules of Softball.” The handle; portion 18 may be wrapped with grip material 22, commonly found in aluminum bats, to prevent hand slippage when swinging the bat 10. The grip material 22 may be formed of rubber, synthetic rubber, foam, tape or other suitable material.
The [0032] body 12 is comprised of a continuous resin matrix reinforced with a plurality of circumferentially-extending fiber socks 24, 26, shown in FIGS. 3 and 4. In the preferred embodiment, the resin components consist of Shell EPON® 826 epoxy resin, DuPont® DCH-99 hardener, and DuPont DYTEK®-A flexiblizer, although other resin components may be used in alternative embodiments. Also, in the preferred embodiment the fiber socks 24, 26 are cross woven and are comprised of 60% glass fiber and 40% carbon fiber, although other types of weaves and other fibers may be used in alternative embodiments.
This particular combination of resin components and [0033] fiber socks 24, 26 results in a high-strength yet flexible body 12. When a ball impacts the bat 10 during the batter's swing, the bat undergoes a localized deformation conforming to the contact area of the ball, as well as radial or hoop deformation (i.e., the cylindrical bat temporarily deforms into an ovoid when viewed in cross section). This deformation provides a springboard or trampoline effect which further enhances the hitting zone of the bat 10 and provides maximum velocity to the ball when hit by the bat.
In the preferred embodiment, five [0034] fiber socks 24, 26 are used in the body 12 of the bat 10 and are concentrically arranged within the resin matrix of the body. The five fiber socks 24, 26 comprise two outer socks 24 and three inner socks 26. The two outer socks 24 substantially extend the entire length of the body 12, while the three inner socks 26 substantially extend the length of the barrel 14, as shown in FIG. 4. This configuration provides the bat 10 with ideal reinforcement properties while at the same time saving weight.
Additionally, the preferred embodiment of the [0035] bat 10 has a cylindrical metal sleeve 28 that is press-fit to the inner surface of the barrel 14. The sleeve 28 functions to dissipate vibration when the ball is hit, thereby converting kinetic energy that would otherwise be transferred to the batter's hands in the form of “stinging”, into heat subsequently lost to the environment. In reducing shock, the sleeve does not reduce the effectiveness of the bat 10 when the bat imparts an impulse on a ball, as elastomeric materials often do. The result is that the “sting” felt by the batter is reduced without adversely affecting the batter's game.
In the preferred embodiment, the [0036] sleeve 28 is comprised of aluminum, as this particular metal has ideal vibration-absorbing properties, but alternative embodiments may utilize sleeves of other types of metals such as titanium and steel. Having a metal sleeve 28 on the inside of the barrel 14 is more beneficial than having a metal sleeve on the outside of the barrel, as the modulus of elasticity of metal is greater than that of a resin matrix. Therefore when a ball is hit by a bat having a metal sleeve on the outside of the barrel, the ball, rather than the bat, deforms, thereby increasing the aerodynamic drag on the ball and resulting in reduced velocity of the ball. It is therefore more desirable to have a barrel having an outer surface of resin matrix, which contributes to the aforementioned springboard or trampoline effect of the bat 10.
The [0037] end cap 19 is comprised of urethane in the preferred embodiment, although end caps constructed of other flexible materials may be used in alternative embodiments. A urethane end cap 19, however, maximizes the above-described trampoline effect of the bat 10, allowing further deformation of the bat upon contact with a ball. The end cap additionally functions to provide the bat with the appropriate weight.
The method of forming the [0038] bat 10 will now be described. The preferred method of forming the bat is described in my copending U.S. patent application Ser. No. 08/910,100, filed Aug. 13, 1997, incorporated herein by reference. This method comprises the steps of concentrically placing the plurality of fiber socks 24, 26 on a removable mandrel. The mandrel is then placed into a press having an outer mold having an internal configuration corresponding to the external configuration of the body 12, whereupon void-free uncured resin is injected into the mold. The resin is then cured where it takes the form of the body 12, which is then removed from the mold. Thereafter, the cylindrical sleeve 28 is press-fit into inside surface of the barrel. The end cap 19 is then molded in place in the end of the barrel 14, and a high-gloss epoxy coating is given to the outside of the body 12. Grip material 22 is then added to the handle portion 18.
It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims. [0039]

Claims

I claim:

1. A ball bat comprising:

a body comprising:

a plurality of circumferentially-extending fiber layers impregnated in a resin matrix;

a barrel having a proximal end and a distal end having an opening adapted to receive an end cap, said barrel further having an inner surface;

a taper portion having a proximal end and a distal end terminating in said proximal end of said barrel; and

a handle portion having a proximal end and a distal end terminating in said proximal end of said taper portion, said proximal end terminating in an integral knob end; and

a central cavity extending along the length of the body.

2. The ball bat according to claim 1 wherein said plurality of fiber layers impregnated in a resin matrix comprise five fiber layers, the layers comprising:

two fiber outer layers extending from said distal end of said barrel to said proximal end of said handle portion; and

three fiber inner layers extending from said distal end of said barrel to said proximal end of said barrel.

3. The ball bat according to claim 1 wherein said resin matrix comprises bisphenol a/epichlorohydrin-based epoxy resin.

4. The ball bat according to claim 1 further comprising a flexible end cap fixedly housed within said open distal end of said barrel.

5. The ball bat according to claim 4 wherein said end cap is comprised of material selected from the group consisting of rubber and plastic.

6. The ball bat according to claim 1 further comprising a metallic sleeve having an inner surface and an outer surface, said outer surface of said sleeve engaging said inner surface of said barrel, said sleeve providing a medium for vibration absorption when said barrel comes into contact with a projectile.

7. The ball bat according to claim 6 wherein said metallic sleeve is made of material selected from the group consisting of steel, titanium, iron and aluminum.

8. The ball bat according to claim 2 wherein each said fiber layer is a cylindrical braid-woven sock.

9. The ball bat according to claim 2 wherein said fiber layers are comprised of materials selected from the group consisting of carbon and glass.

10. A ball bat comprising:

a body comprising:

a handle portion having a proximal end and a distal end terminating in said proximal end of said taper portion, said proximal end terminating in an integral knob end;

a layer of five circumferentially-extending fiber braid-woven socks concentrically arranged and impregnated in a resin matrix, two of said five fiber braid-woven socks extending from said distal end of said barrel to said proximal end of said handle portion, three of said five fiber braid woven-socks extending from said distal end of said barrel to said proximal end of said barrel and concentrically disposed within said two of said five fiber braid-woven socks.

an elongated central cavity extending the length of the body;

a flexible end cap fixedly housed within said open distal end of said barrel; and

a metallic sleeve having an inner surface and an outer surface, said outer surface of said sleeve engaging said inner surface of said barrel, said sleeve providing a medium for vibration absorption when said barrel comes into contact with a projectile.