Abstract:
A bat has a barrel with a multi-wall construction. The handle can be formed integrally with the inner wall. A damping device can be installed between the handle and the outer wall of the barrel. The damping device can dampen vibrations transmitted from the outer wall to the handle. The damping device can also separate the outer wall from the inner wall adjacent the handle section. The inner and outer walls can be bonded together adjacent the end of the bat. Alternatively, the inner and outer walls can be entirely free of bonding to one another. Additionally, a damping device can separate the outer wall from the inner wall adjacent the end of the bat. Furthermore, the bat can include a pair of damping devices that separate the inner wall from the outer wall both adjacent the handle section and at the end of the bat.

Description:
FIELD 
       [0001]    The present teachings relate to composite bats and, more particularly, to multi-wall composite bats. 
       BACKGROUND 
       [0002]    The statements in this section merely provide background information related to the present teaching and may not constitute prior art. 
         [0003]    Baseball and softball bats can be made from composite materials. These bats typically include a handle, a barrel, and a tapered section joining the handle to the barrel. The bats can include a hollow interior, thereby forming bats that are relatively lightweight. The barrel can be of a multi-wall construction. In a multi-wall construction, there is an inner barrel surrounded by one or more outer barrels. Each barrel can act as a tubular spring, or similar structure. Each of the barrels can have the same or different composition. In the multi-wall construction, the barrels can be at least partially separated from one another, thereby allowing the barrels to slide or move relative to one another during an impact with a ball. The ability to slip or move relative to one another separates the bending of the barrels from one another and can distribute the stress between the various walls while allowing greater-force transfer to the ball being hit with the bat. 
         [0004]    The inner and outer barrels can be laminated, cross-linked, or otherwise bonded together (hereinafter referred to collectively as “bonded”) at the end of the bat and also adjacent the tapering section of the bat. The handle can be bonded with either the inner or outer barrels. The bonding together of the inner and outer barrels at both the tip and adjacent the tapering section can increase the vibration in both the inner and outer barrels and transmit the vibrations therebetween. Additionally, the coupling of the handle to either the inner or outer barrels can also transmit vibration through the handle. The vibration transfer can be an undesirable characteristic to a user of the bat. Thus, it would be advantageous to reduce the vibrations that travel to the handle of the bat when striking a ball. Isolating the handle from the barrel, however, can reduce the feel of the bat to the user. In particular, while it is desirable to reduce the vibrations experienced by the user, some tactile sensation of striking the ball with the bat can be desirable and provide a pleasing feel upon contacting the ball. Additionally, a solid connection between the handle and the barrel can enable the bat to have better performance as opposed to a multi-piece construction wherein the barrel and handle are bonded together which results in energy loss during use of the bat. 
         [0005]    Thus, it would be advantageous to reduce the vibrations transmitted to the handle while still providing a tactile sensation for a user of the bat when contacting a ball. Furthermore, it would be advantageous if such construction can utilize a multi-wall barrel, thereby improving the energy transfer to the ball. 
       SUMMARY 
       [0006]    A bat according to the present teachings has a barrel with a multi-wall construction. The handle can be formed integrally with the inner wall. A damping device can be installed between the handle and the outer wall of the barrel. The damping device can dampen vibrations transmitted from the outer wall to the handle. The damping device can also separate the outer wall from the inner wall adjacent the handle section. The inner and outer walls can be bonded together adjacent the end of the bat. Alternatively, the inner and outer walls can be entirely free of bonding to one another. Additionally, a damping device can separate the outer wall from the inner wall adjacent the end of the bat. Furthermore, the bat can include a pair of damping devices that separate the inner wall from the outer wall both adjacent the handle section and at the end of the bat. 
         [0007]    A bat according to the present teachings includes a handle portion adjacent a first end, a barrel portion adjacent a second end, and at least one damping member. The barrel portion can be a multi-wall construction and can include an inner wall and an outer wall that radially surrounds the inner wall. The damping member can be disposed between the inner wall and the outer wall. 
         [0008]    A bat according to the present teachings can include a handle portion adjacent a first end and a barrel portion adjacent a second end. The barrel portion can be a multi-wall construction and can include an inner wall radially surrounded by an outer wall. A tapering portion can connect the handle portion to the barrel portion. There can also be a damping member that dampens vibration between the barrel portion and the handle portion. The inner wall can extend from the first end to the second end and can form the handle portion, the tapering portion, and the barrel portion. The damping member can be disposed on the inner wall. The outer wall can extend from the second end toward the first end and can terminate on the damping member with the damping member separating the inner wall from a portion of the outer wall on the damping member. 
         [0009]    A method of forming a multi-wall composite bat having a damping member, a handle end, and a barrel end can include forming an inner wall with a plurality of plies of composite material and positioning a damping member on the inner wall. An outer wall can be formed with a plurality of plies of composite material so that the outer wall radially surrounds a portion of the inner wall and forms a barrel section of the bat with the damping member separating at least a portion of the outer wall from a portion of the inner wall. The inner and outer walls can be cured in a mold, thereby forming the bat. 
         [0010]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings. 
     
    
     
       DRAWINGS 
         [0011]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present teachings in any way. 
           [0012]      FIG. 1  is a perspective view of a first embodiment of a bat according to the present teachings; 
           [0013]      FIG. 2  is a cross-sectional view along lines  2 - 2  of  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective view of the damping member according to the present teachings; 
           [0015]      FIG. 4  is a perspective view of the ring member; 
           [0016]      FIGS. 5-8  are perspective views of the manufacturing of the bat of  FIG. 1 ; 
           [0017]      FIGS. 9 and 10  are fragmented cross-sectional views similar to that of  FIG. 2  illustrating some of the manufacturing steps of the bat; 
           [0018]      FIG. 11  is a cross-sectional representation of the molding of the bat according to the present teachings; 
           [0019]      FIG. 12  is a fragmented cross-sectional view of an alternate construction for an end of the bat according to the present teachings; 
           [0020]      FIG. 13  is a fragmented cross-sectional view of another alternate construction for an end of the bat according to the present teachings; and 
           [0021]      FIG. 14  is a perspective view of the damping member used at the end of the bat depicted in  FIG. 13 . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    The following description is merely exemplary in nature and is not intended to limit the present teachings, applications, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features (e.g.,  20 ,  120 ,  220 , etc.) 
         [0023]    A baseball or softball bat  20  according to a first embodiment of the present teachings is shown in  FIGS. 1 and 2 . Bat  20  includes a handle portion  22 , a barrel portion  24 , and a tapering portion  26  extending between handle portion  22  and barrel portion  24 . Handle portion  22  has a free end  27  at which a knob  28  or similar structure is located. The end  29  of barrel portion  24  is closed off by a suitable cap or plug  30 . Bat  20  can include an interior cavity  32 . With interior cavity  32 , bat  20  is at least partially hollow, which allows barrel portion  24  of bat  20  to be relatively lightweight so that increased bat speed can be achieved by a user. 
         [0024]    Bat  20  includes a damping member  40  that in some embodiments can be disposed on tapering portion  26 . In other embodiments, damping member  40  can be disposed on handle portion  22 , barrel portion  24 , or at a transition location between handle portion  22 , tapering portion  26 , and/or barrel portion  24 . Damping member  40  can serve to isolate the inner and outer walls of barrel portion  24 , as described below. A finishing ring member  42  can be disposed over damping member  40  and provide a finished appearance for bat  20 . A gripping member  44  can be disposed on handle portion  22 . 
         [0025]    Referring now to  FIG. 2 , bat  20  is a multi-wall construction and includes an inner wall  46  and an outer wall  50 . Inner wall  46  is integral with and forms handle portion  22 , tapering portion  26 , and barrel portion  24 . In some embodiments, outer wall  50  forms barrel portion  24  and part of tapering portion  26  in conjunction with inner wall  46 . In other embodiments, outer wall  50  can be limited to forming only part of barrel portion  24 . In other embodiments, outer wall  50  can form a limited part of handle portion  22  adjacent tapering portion  26  along with barrel portion  24 . The extent to which outer wall  50  forms part of handle portion  22 , tapering portion  26 , and/or barrel portion  24  can be limited by the location of damping member  40  on inner wall  46 . Outer wall  50  radially surrounds inner wall  46 . A bond-inhibiting interface  54  can prevent inner wall  46  from bonding with outer wall  50  wherever bond-inhibiting interface  54  is located. Bond-inhibiting interface  54  thereby allows relative movement between inner and outer walls  46 ,  50  at locations where bond-inhibiting interface  54  is disposed. 
         [0026]    Inner wall  46  is comprised of one or more plies of composite material which can form one or more layers, as described below. Additionally, outer wall  50  also comprises one or more plies of composite material which can form one or more layers, as described below. Additionally, bond-inhibiting interface  54  can comprise one or more plies of material that prevents bonding between inner and outer walls  46 ,  50  during the molding process. The bond-inhibiting interface  54  can extend between inner wall  46  and outer wall  50  along a substantial portion of outer wall  50 . For example, as shown in  FIG. 2 , bond-inhibiting interface  54  can extend from damping member  40  along inner wall  46  and stop short of end  29  of bat  20 . Beyond bond-inhibiting interface  54  adjacent end  29 , inner and outer walls  46 ,  50  can contact one another and form an integral bond therebetween during the molding process. In some embodiments, bond-inhibiting interface  54  can extend all the way to the end of outer wall  50 , as described below. 
         [0027]    Referring now to  FIGS. 1-3 , damping member  40  has opposite first and second ends  60 ,  62  with a conical or tapering section  64  and a generally cylindrical section  66  therebetween. Tapering section  64  has a radial dimension that reduces toward first end  60  and has a shoulder  68  adjacent cylindrical section  66 . First and second ends  60 ,  62  are open with a generally cylindrical cavity  70  therebetween. Cavity  70  allows damping member  40  to be inserted onto bat  20  during the construction process, as described below. Damping member  40  is flexible and is operable to dampen vibrations in bat  20 . Damping member  40  can be made from a variety of materials. By way of non-limiting examples, damping member  40  can be urethane, thermoplastic, a solid rubber, and the like. Additionally, damping member  40  can have a hardness of between about 20 to about 100 on the Shore 00 scale, by way of non-limiting example. Damping member  40  preferably does not bond or cross-link with inner or outer walls  46 ,  50  during the molding process. 
         [0028]    Referring now to  FIGS. 1 ,  2 , and  4 , ring member  42  includes opposite first and second ends  76 ,  78  and a tapering wall  80  extending therebetween. A plurality of openings  82  can be disposed in wall  80 . Openings  82  can allow a user of bat  20  to visually see damping member  40 . Ring member  42  has a cavity  84  extending between first and second ends  76 ,  78  and allows ring member  42  to be inserted onto bat  20  and conceal a majority of damping member  40 . Ring member  42  is attached to bat  20  after the molding process. Ring member  42  is flexible and can be made of a variety of materials. By way of non-limiting example, ring member  42  can be rubber, urethane, thermoplastic, and the like. 
         [0029]    As stated above, inner and outer walls  46 ,  50  can each be constructed with one or more plies of composite material. The composite material, by way of non-limiting example, can be fiber-reinforced and may include glass, boron, carbon (graphite), aramid, ceramic, and/or any other suitable reinforcement material. The various plies can be pre-impregnated with a laminating adhesive to bond the various plies together during the molding process, as known in the art. The plies can take a variety of forms. By way of non-limiting example, the plies can be a unidirectional material-tape, woven fabrics, braided fabrics, randomly oriented fibers, and the like. 
         [0030]    Referring now to  FIGS. 5-10 , construction of bat  20  according to the present teachings will be shown. A mandrel  90  is used to form bat  20 . Mandrel  90  is generally shaped in the configuration desired for the interior cavity  32  of bat  20 . Inner and outer walls  46 ,  50  are formed by wrapping multiple plies  94  of composite material on mandrel  90 . The plies  94  are wrapped on mandrel  90  in various orientations to provide a desired construction for bat  20 , as known in the art. 
         [0031]    Initially, inner wall  46  is formed on mandrel  90  by wrapping multiple plies  94  of composite material over the surface of mandrel  90 . The initial plies  94  can include a tissue or other backing that prevents the initial plies  94  from sticking to mandrel  90 . Successive plies  94  are wrapped along mandrel  90  from the handle section through the barrel section with the plies overlapping one another. The plies  94  can be pre-impregnated and contain the adhesive therein. 
         [0032]    After inner wall  46  has been formed to a predetermined level, a braided fabric tube  96  is slid over the handle side of mandrel  90  and positioned on bat  20 , as shown in  FIG. 6 . Braided fabric tube  96  can be dry (not pre-impregnated). Braided fabric tube  96  will form an integral part of handle portion  22 . After securing braided fabric tube  96  in place, the inner wall  46  continues to be built up using additional plies  94  that are wrapped over braided fabric tube  96  and the rest of inner wall  46 . Plies  94  continue to be applied to mandrel  90  until the entire inner wall  46  has been constructed, as shown in  FIG. 7 . 
         [0033]    With the construction of inner wall  46  complete, damping member  40  can be positioned on mandrel  90  from the handle end. Damping member  40  is positioned on inner wall  26  at a desired location, such as the location shown in  FIG. 8 . 
         [0034]    Once damping member  40  is in its desired location, bond-inhibiting interface  54  is formed on bat  20 . Bond-inhibiting interface  54  can be disposed on bat  20  between damping member  40  and end  29 . Bond-inhibiting interface  54  prevents the adhesives in inner and outer walls  46 ,  50  from bonding with one another, as known in the art. Bond-inhibiting interface  54  can be formed by one or more plies of materials that do not cross-link or adhere to the adhesive used in the inner and outer walls  46 ,  50 . By way of non-limiting example, bond inhibiting interface  54  can be formed from one or more plies of polypropylene or other thermoplastic films. The bond-inhibiting interface  54  can stop short of end  29 , thereby allowing inner and outer walls  46 ,  50  to bond together at end  29 . 
         [0035]    Next, outer wall  50  is formed by applying one or more plies  94  over top of inner wall  46  from damping member  40  to end  29 . The plies  94 , as shown in  FIG. 9 , can extend over top of cylindrical section  66  of damping member  40 . Outer wall  50  is built up by applying the plies  94  in differing locations and in differing orientations to provide a desired construction for outer wall  50 . 
         [0036]    At some point during construction of bat  20 , one or more of the plies  94  that form outer wall  50  are wrapped around cylindrical section  66  and extend from at least cylindrical section  66  over top of shoulder  68  and tapering section  64 , thereby forming a flap  98 , as shown in  FIG. 9 . Additional plies  94  are applied on top of the existing construction of outer wall  50  to form the desired thickness of outer wall  50 . These additional plies can extend over the portion of flap  98  that is between tapering section  64  and end  29  of bat  20 . Once outer wall  50  has been formed to the desired construction, flap  98  can be folded forwardly over top of the existing plies that form outer wall  50 , as shown in  FIG. 10 . This construction allows flap  98  to sandwich the ends of plies  94  that are adjacent shoulder  68  together and form a finished construction. 
         [0037]    Once outer wall  50  has been formed, mandrel  90  is removed from bat  20  and bat  20  is positioned within a mold  106 . The end  29  of bat  20  can be formed by pushing the various plies that form inner and outer walls  46 ,  50  into the interior cavity  32  of bat  20 . An air bladder  110  is positioned within interior cavity  32  and communicates with an air source  112  which is exterior to mold  106 . Within mold  106 , air bladder  110  is filled with air from air source  112  to pressurize interior cavity  32  and force bat  20  radially outwardly against the mold  106 . Additionally, mold  106  can be heated to facilitate the bonding and curing of the adhesives in the various plies used to form inner and outer walls  46 ,  50 . The molding process is well-known in the art and, as such, will not be described further. 
         [0038]    After molding bat  20  in mold  106 , bat  20  is removed therefrom. The handle portion  22  can have foam  116  inserted therein along with one or more weights  118 . Foam  116  seals interior cavity  32  at end  27  while weights  118  can provide a desired weighting for bat  20 . 
         [0039]    End  29  is formed by cutting or trimming the ends of the various plies that form inner and outer walls  46 ,  50  adjacent end  29 . Once trimmed, cap  30  is pressed into end  29  and pawls  31  secure cap  30  thereto. Bat  20  can be sealed and painted to provide a desired exterior appearance for bat  20 . Ring member  42  can also be inserted over bat  20  and positioned on top of damping member  40 . In some embodiments, the molding of bat  20  can leave depressions around damping member  40  that facilitate the positioning and retention of ring member  42  on bat  20 . 
         [0040]    In the final construction of bat  20 , as shown in  FIG. 2 , cylindrical section  66  of damping member  40  separates inner wall  46  from outer wall  50  at tapering portion  26 . This separation dampens vibration in outer wall  50  from traveling to inner wall  46  and handle portion  22  through tapering portion  26 . Additionally, damping member  40  also serves to dampen vibrations within inner wall  46  and can inhibit the traveling of vibrations from barrel portion  24  of inner wall  46  to handle portion  22 . Furthermore, the integral construction of handle portion  22  with barrel portion  24  through inner wall  46  allows for a desirable tactile sensation when striking a ball with bat  20  along with good performance and force transfer to the struck ball. 
         [0041]    In some embodiments, the thickness of inner wall  46  of barrel portion  24  can be the same as the thickness of outer wall  50  of barrel portion  24 . In  FIG. 2 , outer wall  50  is shown as formed with multiple discrete layers  50 a,  50 b that are bonded together. It should be appreciated that these discrete layers are merely representative in nature and that outer wall  50  can be formed from a single layer of multiple plies  94  or more than two discrete layers, as desired. Additionally, it should also be appreciated that the thickness of bond-inhibiting interface  54  is shown in the figures for illustration purposes only and that the thickness of bond-inhibiting interface  54  can vary from that shown based upon the desired construction of bat  20 . 
         [0042]    The location of damping member  40  on bat  20  can vary based upon the physical construction of bat  20  and the desired characteristics for bat  20 . The vibrational bending modes of a bat can include a fundamental or first bending mode, a second bending mode, and a third bending mode. These differing modes can have vastly different frequencies and amplitudes. The bending modes can effect the location of the “sweet spot” of the bat. In some embodiments, damping member  40  is preferably located at the average anti-node of the first and second vibrational bending modes for the bat. The positioning of damping member  40  at the average anti-node can result in damping member  40  being located at a position wherein a non-damped vibration for the first and second modes would be at their greatest amplitude (i.e., the anti-node). The locating of damping member  40  to reduce the amplitude of the vibrations caused by the first and second modes can be balanced against the impact of damping member  40  on the “sweet spot” of bat  20 . Further, it should be appreciated that the position of damping member  40  between inner and outer walls  46 ,  50  can alter the frequencies of the first and second vibrational bending modes versus that of a bat of a conventional construction without damping member  40 . 
         [0043]    Referring now to  FIG. 12 , the construction of an alternate bat  120  according to the present teachings is shown. Bat  120  is similar to bat  20  described above. As such, only the differences will be described herein. In bat  120 , bond-inhibiting interface  154  extends all the way to end  129 . As a result, outer wall  150  is not bonded to inner wall  146  at any location. The tapering of the tapering portion along with the compression molding process imparts interference fit-type mechanical arrangements that prevent outer wall  150  from separating from bat  120  during use. The entire separation of inner and outer walls  146 ,  150  from one another can advantageously allow for additional slip therebetween, thereby facilitating the transfer of stress through the walls while imparting a significant force to a ball hit by bat  120 . 
         [0044]    Thus, in some embodiments bat  120  can have an outer wall  150  that is entirely free from bonding with inner wall  146 . Additionally, a damping member can be disposed between inner and outer walls  146 ,  150  in the tapering portion of bat  120 . 
         [0045]    Referring now to  FIG. 13 , the construction of yet another bat  220  according to the present teachings is shown. Bat  220  is similar to bat  20  discussed above. As such, only the differences between bat  220  and bat  20  will be described. In bat  220 , a second damping member  241  is disposed between inner and outer walls  246 ,  250  at end  229 . Second damping member  241  extends from end  229  partially along barrel portion  224 . Second damping member  241  can include a tapering section  286  that tapers toward the handle portion of bat  220 . The other end of second damping member  241  can curve radially inwardly to form a radial opening  287  that forms a part of end  229  and thereby maintains inner and outer walls  246 ,  250  separate from one another. Tapering section  286  extends either beneath, as shown, or above (not shown) bond-inhibiting interface  254 . As such, bat  220  maintains outer wall  250  entirely isolated from inner wall  246  such that there is no bonding therebetween. As a result, additional damping of vibrations of bat  220  can be achieved while still maintaining desirable tactile sensations to a user of bat  220 . 
         [0046]    Thus, a bat according to the present teachings can utilize a damping member to dampen vibrations of the bat. Additionally, the damping member can serve to separate the outer wall from the inner wall, thereby reducing vibration transfer to the handle of the bat. The integral nature of the handle portion with the inner wall of the barrel provides a desirable tactile sensation when striking a ball with the bat. 
         [0047]    It should be appreciated that while the bats according to the present teachings are shown and described with reference to specific examples, that such illustrations and descriptions are merely exemplary in nature and that variations can be employed without deviating from the spirit and scope of the present teachings. For example, while the bats are shown as having inner and outer walls, more than two walls can be employed. Furthermore, the location of the damping member can change from that shown. Additionally, the physical shape and dimensions of the damping members can also vary from that shown. Thus, the description and illustrations used in describing the present teachings are merely exemplary in nature and variations can be employed without deviating from the spirit and scope of the present teachings.