Abstract:
A baseball bat having a sleeve surrounding a portion of the narrow exterior surface of the bat for prevention of scattering of splinters and wood projectiles should the bat shatter during use. The sleeve is formed of wound fabric and secured mechanically at both ends to the exterior surface of the bat. The securement using a groove or ridge and traverse fibers engaged with the sleeve allows the sleeve to stretch and absorb energy and prevents a total separation of the heavy end of the bat from the handle from becoming airborne where it could cause serious injury.

Description:
[0001]    This application claims priority to U.S. Provisional Patent Application No. 61/075,704 filed Jun. 25, 2008, and which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This disclosed device and method relate to the field of baseball bats. More particularly, the device and method herein provide for wooden baseball bats which are reinforced with fiber wrapped exteriors and a mechanical engagement of the fibers to the wooden bat, to thereby yield a bat which will prevent the separation of large and small pieces of wood from a shattered bat which otherwise would become dangerous projectiles. So reinforced, the bats help ensure the safety of players and spectators during such an occurrence. 
       BACKGROUND OF THE INVENTION 
       [0003]    The game of baseball has long employed the use of wooden bats to strike handballs thrown by the pitcher. While college leagues and many little leagues have changed to metal bats, players at the professional level, in the minor leagues, and in other leagues continue to prefer hardwood bats for striking the ball. 
         [0004]    In years past, most major league teams employed bats made of ash wood which occasionally break when striking a ball. More recently, the major league players have moved to employ maple bats instead of ash due to a perceived performance enhancement using bats made from this wood. However, maple has an inherent proclivity to fracture in a manner where little energy is absorbed by the bat yielding clean fractures. Such clean fractures and lack of energy absorption produce projectiles which travel further and at velocities which can cause severe injury should they strike a player, umpire, or a fan. 
         [0005]    Whether maple or another wood, the projectiles formed by pieces of a shattered bat, tend to have sharp jagged fracture surfaces which are extremely dangerous to players, fans and crew members. Frequently, a separation of the wood forming the bat, caused by the force of the bat striking a ball, can send shreds of wood in many directions at high velocities. Players adjacent to the breaking bat, such as the batter and catcher, and the umpire, are at extreme risk of injury from the flying debris. However, even people many yards away, such as the pitcher, or spectators in the stands have been injured from the projectiles formed by flying wooden pieces of a shattered bat. Many have suffered injuries from penetration of the skin by wooden slivers, to broken jaws caused by the impact of large pieces of the broken bat flying at high velocities. 
         [0006]    A bat will typically initiate failure in the thinner region of the handle and in the transition region from the handle to the barrel. When the ball strikes the bat near the end of the barrel or in the transition region, the forces of the impact cause an intense shock load that excites the fundamental bending mode of the bat. Bending of the bat in this manner puts high stresses on the exterior of the bat. If there is a flaw such as a crack near the surface, the crack can quickly propagate through the entire bat. 
         [0007]    Maple wood has a generally uniform structure where seasonal layers are hard to distinguish. Ash on the other hand, has easily discernable distinct growth layers. These layers consist of early wood which is a soft and porous layer which grows during the warmer seasons, and late wood which is hard and dense and grows during the cooler seasons. 
         [0008]    Because ash wood has a non uniform layering structure, when a bat made from ash wood fractures, the layers tend to separate creating a leaf spring structure. Cracks in an ash wood bat tend not to propagate through the hard and soft layers. 
         [0009]    For maple bats, because maple has a uniform hard layer structure, cracks propagate readily through the bat section with little energy loss. Recent efforts by Major League Baseball to minimize the failure rates of maple wood bats include increasing the diameter of the handle and tapered region, and specifying a grain slope less than one inch over a twenty-inch bat length. Additionally, players must strike the ball with the face of the grain on the bat opposite what players would normally do with an ash bat. 
         [0010]    Additionally, nine new rules were recommended in an effort to minimize maple bat failures. However, some of these rules will most certainly discourage players from using maple bats and manufacturers of bats will have a hard time surviving under the new rules if they continue the manufacture of maple bats. Further, maple wood inherently has a hard uniform structure so cracks can propagate through the wood regardless of the new rules and despite such rules, it can&#39;t be guaranteed that a player will in fact keep the bat rotated correctly. 
         [0011]    Because maple bats do have the perceived advantage for being very hard and imparting more energy to the ball, they will continue to be more favored for use. This hardness is one reason players like them since a pitched ball will bounce or rebound off a harder bat with more velocity. Ash bats being softer, tend to absorb energy in the soft pores. Another reason maple bats are favored is that they tend not to dent or splinter at the barrel from prolonged use. Maple bats, even with their tendency to yield high velocity shards upon shattering, because of their perceived benefits, will be a popular choice of players in the foreseeable future. Consequently, it is important that they be made safer to ensure the safety of both players and spectators. 
         [0012]    Attempts have been made in the past to strengthen bats by employing wrappings of synthetic materials and resins. While such wrappings generally contain smaller pieces of wood from a shattered bat, large pieces of shattered bats have sufficient mass to develop sufficient force to separate from conventional fabric and resin reinforcements which are simply adhered to the exterior surface of the wood bat. 
         [0013]    As such, there exists an unmet need for a device and method yielding reinforced wooden baseball bats to protect players and spectators from flying debris. Such a device should be sufficiently light weight not to affect the bat balance, weight or natural frequency. Such a device should have sufficient mechanical engagement of the fiber wrapping employed to strengthen the bat, to also insure that large pieces of a shattered bat moving at higher forces, do not separate from the fiber engagement providing the restraint. 
       SUMMARY OF THE INVENTION 
       [0014]    The disclosed device and method herein is directed to a method of bat reinforcement which yields a safer wooden bat and which does not alter its strength or performance. Using a method of fiber-wrapped reinforcement, the method herein yields a bat which has wrapped fibers in a mechanical engagement with small grooves formed in the exterior bat surface. The method provides a means to prevent large and small pieces of the bat formed, from becoming projectiles due to their high force during a bat fracture associated with a ball and bat impact. 
         [0015]    It is desired in most baseball leagues where statistics on players and historical data as to performance are essential to the legacy of the sport, that the equipment that players employ over time will not change significantly. Such consistency allows for player records and statistics to be accurately compared over many decades. 
         [0016]    With this in mind, the disclosed method and device provided thereby yields the reinforcement and containment necessary to prevent shards and projectiles from becoming airborne, while still maintaining the bat itself sufficiently similar in performance to non-reinforced bats. If a bat and ball impact would cause a non-reinforced bat to break, then that same interaction is desired for the reinforced bat in order to maintain the continuity of the equipment used by the players in accordance with previous equipment. However, after the break, a bat formed by the method herein will cause a containment of the larger shards and projectiles which would conventionally separate from the bat. 
         [0017]    In the current preferred mode of the device, this similar behavior is accomplished by one or a combination of: 
         [0000]    1) Minimizing the amount of reinforcement to less than 1% the mass of the bat.
 
2) Minimizing the modulus of the fiber employed for reinforcement.
 
3) Employing high strength fiber so as to absorb energy on a shatter of the bat.
 
4) Employing a fiber matrix interface allows the fiber to absorb energy efficiently during a bat failure.
 
5) Employing some type of mechanical engagement of traverse fibers to engage them mechanically to the wood of the bat in at least two positions thereby providing a capture component, and to maintain the fiber matrix in position around the thinner portions of the bat which are most liable to shatter and to prevent larger sections from separating.
 
         [0018]    The disclosed device employs fibers which are wrapped around the exterior of the bat. Where safety is of the sole focus of the reinforcement, then the fibers selected should have a low modulus of elasticity and high strength. The lower modulus will minimize its effect on the bat&#39;s fundamental frequency or strength to maintain consistency of performance with bats of prior years. With a higher modulus, the fiber will increase its participation in a ball strike by absorbing more load. 
         [0019]    The fiber tows are wound by hand or by CNC filament winder. The fibers are preferably wound along an axial direction between 0°+/−30° (low angle fibers) relative to the long axis of the bat, and traverse to the long angle fibers from +/−30° to +/−50° (off-axis fibers). The low angle fibers are wound first and this step may employ jigs or pegs or other means to temporarily maintain the fibers in place until the off-axis fibers are engaged. The traverse off-axis fibers are subsequently wound and employed to hold the low angle fibers snug against the exterior bat surface thereby forming a containment component for shards or pieces of the bat which might separate during impact with the ball. 
         [0020]    The wrapping of fibers extends in the favored mode, substantially from the knob end of the bat, to about 12 inches from the distal end of the barrel of the bat. The distance of the wrapping between both ends thereof is substantially between 55-65 percent of the bat total length with 62% of the bat length having been tested to be especially effective and therefor being an especially preferred length for the wrapping. 
         [0021]    The fibers forming the wrapping to yield the containment component, may be any fiber suited to the task and goal with two favored fibers being Kevlar or Spectra. Of course those skilled in the art will realize that other fibers may be very well suited to the task of forming a containment component mechanically engaged to a bat at both ends, and all such fibers as would occur to those skilled in the art are anticipated within the scope of this application. 
         [0022]    Once wound on the bat, a thin epoxy layer or polyurethane or varnish or other coating appropriate to the task is applied to the bat and to the wound fibers to lock the fibers in place to form the containment component for flying shards and debris in the event of a break, and to provide the bat with a durable finish. 
         [0023]    To maintain the bat within the scope of bats employed in previous seasons, preferably the mass of the reinforcement is typically less than 1% the mass of the bat to which it is engaged. The effect of the reinforcement on strength and stiffness of the bat should be minimal however. Rather than yield a stronger, stiffer bat which as noted would inhibit comparison of player statistics with those of the past, the ultimate objective of the formed reinforcement is to retain shattered pieces of the bat from becoming airborn. This is accomplished by the fiber wrap forming a containment component mechanically engaged at two ends to the bat and restraining separating bat pieces from becoming airborne. 
         [0024]    The following table summarizes the properties of several different fiber types. The fiber with the highest specific tensile strength is the Spectra 900 fiber which is a high-strength, lightweight fiber, formed of polyethylene. A polyethylene fiber with these performance characteristics is preferred because it is very lightweight, has a high strength, and is durable and translucent when coated with a clear matrix. 
         [0025]    Another good trait of polyethylene fiber such as Spectra 900 is that the surface finish of the fiber is smooth and it thus does not adhere well to resins. This slippage or non adherence is important in that it allows the fibers to slip through their matrix during a bat failure allowing the fiber forming the containment component to absorb more energy. 
         [0026]    Another preferred fabric for wrapping the bat is formed of aromatic polyamide such as Kevlar-29 fiber. This type of fiber also has very high tensile strength and is lightweight. It has a modulus lower than the polyethylene fabric such as the Spectra 900 which makes it a good candidate for the device herein. Aromatic polyamide however, is generally not translucent when coated with an epoxy and it also yields a fiber matrix strength higher than the polyethylene fiber. A table below provides examples of fibers and their respective characteristics. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 Fiber Property Comparison (SI Units) 
               
             
          
           
               
                   
                   
                 Density 
                 Modulus 
                 Tensile 
                 Specific TS 
               
               
                 Fiber 
                 Description 
                 (g/cm{circumflex over ( )}3) 
                 (GPa) 
                 Strength (GPa) 
                 (Gpa * cm{circumflex over ( )}3/g) 
               
               
                   
               
               
                 Spectra 900 
                 HS Polyethylene 
                 0.97 
                 75.0 
                 2.5 
                 2.6 
               
               
                 Kevlar-29 
                 Aromatic Polyamide 
                 1.44 
                 54.0 
                 2.4 
                 1.7 
               
               
                 E-Glass 
                 Silica Glass 
                 2.55 
                 72.4 
                 3.4 
                 1.4 
               
               
                 T300 
                 Carbon 
                 1.76 
                 231.0 
                 3.7 
                 2.1 
               
               
                 Steel Wire 
                 Steel 
                 7.76 
                 200.0 
                 2.0 
                 0.3 
               
               
                   
               
             
          
           
               
                 (US Customary Units) 
               
             
          
           
               
                   
                   
                 Density 
                 Modulus 
                 Tensile 
                 Specific TS 
               
               
                 Fiber 
                 Description 
                 (in/lb{circumflex over ( )}3) 
                 (Msi) 
                 Strength (Ksi) 
                 (Ksi * in{circumflex over ( )}3/lb) 
               
               
                   
               
               
                 Spectra 900 
                 HS Polyethylene 
                 0.035 
                 10.9 
                 363 
                 10352 
               
               
                 Kevlar-29 
                 Aromatic Polyamide 
                 0.052 
                 7.8 
                 348 
                 6694 
               
               
                 E-Glass 
                 Silica Glass 
                 0.092 
                 10.5 
                 500 
                 5435 
               
               
                 T300 
                 Carbon 
                 0.064 
                 33.5 
                 531 
                 8353 
               
               
                 Steel Wire 
                 Steel 
                 0.280 
                 29.0 
                 285 
                 1018 
               
               
                   
               
             
          
         
       
     
         [0027]    As noted, while the device and method herein is intended to form a containment component on a bat to act as a safety net to retain wood projectiles on failure of the bat, this type of fiber reinforcement can also be used to increase strength or performance if desired and allowed. By simply selecting a fiber with higher modulus and better a stiffer, stronger, fiber-matrix interface strength such as a carbon fiber T300, and by increasing the mass percentage of the reinforcement primarily in the low angle direction, a significant increase in the fundamental bending mode and strength can be attained. However, such enhancements would obviously have to be league-approved to be employed as they would form a bat with strength characteristics inconsistent with bats of the past. 
         [0028]    With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the formed bat device, and methods herein forming the device, shall include variations in size, materials, shape, form, function and manner of operation, assembly and use, which would be readily apparent and obvious to one skilled in the art. Consequently all equivalent relationships to those illustrated in the drawings and described in the specification which would occur to those skilled in the art are intended to be encompassed by the present invention. Therefore, it should be understood that the foregoing summary and following detailed description are to be considered as illustrative only of the principles of the invention. 
         [0029]    Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and method of formation shown and described, and accordingly, all suitable modifications and equivalents which may be resorted to, shall be considered as falling within the scope of the invention. 
         [0030]    Still further, it is to be understood that the phraseology and terminology employed herein are for the purpose of description of the principals of the device and method herein, and should not be regarded as limiting in any fashion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]      FIG. 1  depicts a side view of a bat having the formed containment component thereon covering a portion of the bat and in an engagement with the bat at two formed recesses or surface level changes. 
           [0032]      FIG. 2  depicts a slightly raised exterior surface providing one manner of physical engagement of an end of the attached containment component. 
           [0033]      FIG. 3  depicts a groove formed in the bat exterior surface adjacent to the knob end and providing another mode of engagement the end of the containment component formed by the fibers. 
           [0034]      FIG. 4  shows a side view of a preferred mode of a baseball bat showing the containment component formed of wrapped fibers axially disposed in the range at substantially 0° and with fibers traverse to the axis at an angle of +/−45° with end portions of fibers anchored in grooves. 
           [0035]      FIG. 5  depicts another mode of the device herein showing the fiber wrap formed of planar fibers in a double spiral and two ends engaged in grooves. 
           [0036]      FIG. 6  depicts a single spiral wrap of planar fibers in a spiral terminating within the opposing grooves on the surface of the bat. 
           [0037]      FIG. 7  shows a preferred mode of the device having the fiber wrap formed of both axially disposed fibers encompassed by a single spiral wrap holding the axial fibers and place and with fibers anchored in the grooves of the surface. 
           [0038]      FIG. 8  depicts a mode of the device wherein the fibers are wound at +/−10° in the low angle and +/−50° in the high angle. 
           [0039]      FIG. 9  depicts a mode of the device wherein the mesh net forming the containment component is knitted or woven in a circular tube and then heated or otherwise shrunk onto the bat and into the grooves. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0040]    Referring now to the drawings in  FIGS. 1-9 , wherein similar parts are identified by like reference numerals, there can be seen in the various figures, depictions of favored modes of the device  10  yielded by the method herein. 
         [0041]    All of the embodiments of the device  10  yielded by the method herein, employ fibers  14  to form a capture component  16  around the narrower portions of a baseball bat  12 . As shown in  FIG. 1 , in a bat  12  having a conventional length “L” the capture component  16  in the preferred mode has a length L 1  covering more than half the length L of the bat  12 . Currently the capture component is formed to have a length L 1  which surrounds between 45-65 percent of the length L, of the bat  12 . A particularly preferred capture component  16  length L 1 , is substantially 62 percent of the bat length L. 
         [0042]    The formed capture component  16  additionally employs traverse windings of the fibers  14  at both ends to mechanically engage the capture component  16  to the bat  12 . This engagement allows broken parts of the bat to slip but provides a means to maintain larger broken sections of the bat  12  proximate to each other should a severe break occur as the fibers  14  forming the capture component  16  will stretch but hold. This engagement of the two ends of the capture component  16  overcomes the shortcomings of prior art which can allow larger portions of a broken bat  12  to shear from their engagement with the fibers  14  which are simply wound onto the bat and adhered without any mechanical connection to prevent such an occurrence. 
         [0043]    As shown in  FIG. 1 , the capture component  16  extends from a first end  18  adjacent to the knob  20  portion of the bat  12  to a second end  22  and encircles the mid section of the bat  12 . At the first end  18  of the bat  12  as shown in  FIG. 3 , a recess  25  is formed on the exterior surface of the bat  12  by either cutting a groove into the surface or forming a small ridge  17  as shown in  FIG. 2 . These formed recesses  25  at both ends of the capture component  16 , provide a mechanical engagement of both ends of the capture component  16  to the bat  12  at the recess  25  positions through the winding of fibers  14  traverse to the axis  28  and into the recesses  25 . 
         [0044]    In  FIG. 4 , there is shown a capture component  16  in a preferred mode of a baseball bat  12  wherein the mesh net forming the capture component  16  is formed by the axially disposed and traverse wound fibers  14 . As depicted, the axially disposed fibers  14  are positioned at substantially 0° with the traverse wound fibers  14  being wound spirally at angles substantially of +/−45°. Fibers  14  at the first and second ends of the capture component  16  are substantially perpendicular to the axis  28  and engaged within the recess  25  formed by a groove  23  or raised portion  17  of the bat  12 . Thus, the recesses  25  provide an anchoring means of both ends of the capture component  16  to the portions of the bat  12  where they are engaged. 
         [0045]    As is well known in the art, bats  12  tend to break at the thinner sections of the bat  12  which would be completely covered by the capture component  16  and thereby prevented from becoming airborn projectiles upon a break. In a serious break of the bat  12 , larger sections can dislodge and due to their larger mass, can become airborn for substantial distances. This is especially true of sections on the distal end  19  of the bat  12  where the second end  22  of the capture component  16  is engaged in the recess  25 . The traverse fibers  14  engaged within the recesses  25  provide a means to restrain such larger portions of the bat  12  which heretofore would shear from the engagement of the fibers  14  and glue, epoxy, or other resinous coating holding the fibers  14  to the bat  12 . 
         [0046]    The capture component  16  between its two ends, serves as a net to capture wood pieces which might become airborne on a break and also to protect the user from the sharp points that can develop on a complete break of the bat  12  in the thinner section surrounded by the capture component  16 . 
         [0047]    There are many configurations of the capture component  16  that can be wound and woven and those skilled in the art will no doubt realize such upon review of this specification. Any combination of axial and traverse fibers  14  to form the capture component as would occur to those skilled in the art are anticipated within the scope of this application. The overriding factor is that at least the second end  22  of the capture component  16  should be engaged by fibers  14  traverse to the axis  28  and engaged with a recess  25  formed by either a grove  23  as in  FIG. 3 , or ridge  17  as in  FIG. 2 , formed on the bat  12  surface. Additionally, the fibers  14  may be of any dimensional characteristics, be it planar or round or oval, so long as they are engaged to form the capture component  16  and engaged with at least one, and preferably both recesses  25 . 
         [0048]    As shown in  FIG. 4 , the configuration features axially disposed fibers  14  encircled by traverse fibers  14  in a double spiral to form the capture component  16 . The ends  18  and  22  are engaged in the recesses  25  which would be formed on the bat  12  surface. 
         [0049]    Another preferred configuration is that of  FIG. 5  wherein the capture component  16  is formed of another mode of the device herein showing the fiber net formed of planar fibers  14  in a double spiral wind and without the axially disposed fibers  14 . At the first end  18  and second end  22  of the formed capture component  16  the fibers  14  are engaged with the recesses  25 . The spirals run at +/−45 degree angles to the axis  28  in a preferred mode. 
         [0050]    In a third preferred configuration of the capture component  16  in  FIG. 6 , the capture component  16  is formed in a single spiral wrap of planar fiber  14  and terminating at both ends  18  and  22  in a traverse engagement of the fibers  14  in the formed recesses  25 . 
         [0051]    Yet another preferred mode of the device of  FIG. 7  depicts the capture component  16  formed of fibers  14  positioned axially which are encompassed by a single spiral wrap of fiber  14  holding the axial fibers  14  in place. Both ends  18  and  22  as in all modes of the device  10  are anchored to the bat  12  by fibers  14  engaged traverse to the axis  28  and engaged with the recesses  25  properly positioned at the ends and formed by groves or ridges or other means. 
         [0052]    Finally, in another mode of the device  10  in  FIG. 8 , the capture component  16  is formed of axially positioned fibers at substantially a +/−10° angle to the axis  28  and traverse fibers  14  wound to hold the axial fibers  14  in place at +/−50° from the axis  28 . Both ends  18  and  22  of the formed capture component  16  have fibers  14  are engaged in the recesses  25  formed preferably perpendicular and traversing the axis  28 . 
         [0053]    All fibers  14  engaged in the recesses  25  of the embodiments herein may be one or a combination of the axial and traverse fibers  14  or at a position wherein an axial fiber  14  may transition to a traverse fiber  14  if wound in that fashion, with the overriding factor being a secure engagement of both ends  18  and  22  of the formed capture component  16  into recesses  25  in the bat surface formed by cutting grooves or forming ridges and engaging the fibers  14  on the opposite side of the ridge from where the end  18  or  22  of the capture component  16  abuts it. 
         [0054]    There is shown in  FIG. 9  another mode of the device  10  wherein the capture component  16  may be preformed or woven slightly larger than the bat  12  circumference and slid over one end. Once thereon, the capture component formed of the fibers  14  in the desired configuration may be shrunk by heating the fibers  14  wherein the ends  18  and  22  will engage with the recesses  25 . 
         [0055]    It is to be understood that elements of different construction and configuration and different steps and process procedures and other arrangements thereof, other than those illustrated and described, may be employed for providing the baseball bat with fabric formed safety net and reinforcement and any method herein within the spirit of this invention. 
         [0056]    As such, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modifications, various changes and substitutions are intended in the foregoing disclosure, and it will be appreciated that in some instance some features of the invention could be employed without a corresponding use of other features without departing from the scope of the invention as set forth in the following claims. All such changes, alternations and modifications as would occur to those skilled in the art are considered to be within the scope of this invention as broadly defined in the appended claims.