Patent Abstract:
The present invention is a sports implement for hitting a pitched object. The sports implement includes attachments for a contact end of the implement allowing variation of the weight and/or length of the sports implement.

Full Description:
FIELD OF THE INVENTION  
         [0001]    The present invention pertains to adjusting the weight of a sports implement, and more particularly to adjusting the weight of the barrel end of a baseball bat to allow the weight to be tailored to an individual batter.  
         BACKGROUND OF THE INVENTION  
         [0002]    The size, weight, and shape of a baseball bat effects the kinematics of the swing of the baseball bat by a batter. The weight of the barrel end affects the ability of the batter to swing the bat rapidly enough to meet a pitched ball. A heavier barrel end requires greater strength to achieve the same barrel speed as a lighter barrel end. A heavier barrel end, however, carries greater momentum when a pitched baseball is struck. In addition to the weight of the barrel end of the bat, the length of the bat also affects the ability of a batter to both control the swing, as well as generate an effective barrel velocity at impact with a pitched ball.  
           [0003]    Typical baseball bats are formed from a substantially homogenous material, such as wood or aluminum. Some bats are formed from multiple materials, such as using a fiberglass handle with an aluminum head. Notwithstanding, these bats are formed with a fixed weight of the barrel end, fixed length, and fixed grip size.  
           [0004]    In addition to affecting the swing of the bat at a pitched ball, it is typical for a batter to desire a heavier barrel end of the bat for practice swings, to both build up and stretch the muscles used for swinging the bat. To this end, doughnuts may be provided. Doughnuts are toroidal shaped weights that may be placed around the barrel end of the bat to add weight to the barrel. The use of a doughnut precludes the ability of the batter to actually hit a ball when the doughnut is on the bat, since the doughnut does not provide a uniform hitting surface.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention is a sports implement for hitting a pitched ball or the like. The contact end of the sports implement is adapted to allow the selective engagement of varying weights or contact extensions, hereinafter further referred to collectively as attachments, to the sports implement, allowing weight and/or length parameters of the sports implement to be varied as desired for individual users of the sports implement, or as desired at various times by an individual user.  
           [0006]    The barrel end of the sports implement may be provided with a system for allowing weights in the barrel end of a baseball bat to be easily substituted to allow varying the barrel weight of a bat, without varying the hitting surface of the bat. Such a system may include weights having a smaller diameter than the contact surface of the sports implement, such that the weights nested within the end of the sports implement.  
           [0007]    The attachment could also have an outer size and shape consistent with the sports implement, allowing the attachment to form a portion of the contact surface of the sports implement.  
           [0008]    The attachment may be engaged to the sports implement by any method however the use of a threaded joint as a bayonet joint allows rapid engagement and removal of an attachment from the sports implement.  
           [0009]    Biasing means may be provided to ensure that an attachment engaged to a sports implement remains engaged until such time as a user decides to remove the attachment. The biasing means may include an elastic element urging portion of the attachment and the sports implement into contact, or creating a friction or other retaining force to maintain engagement of the attachment to the sports implement. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0010]    [0010]FIG. 1 illustrates a sports implement having a female socket receptacle for engaging a weight to the end of a sports implement.  
         [0011]    [0011]FIG. 2 illustrates a weight for a sports implement where the weight nests in the end of the sports implement without forming a portion of the contact surface of the sports implement.  
         [0012]    [0012]FIG. 3 illustrates a sports implement having a female socket formed within a weight for engaging a post on the end of a sports implement.  
         [0013]    [0013]FIG. 4 illustrates a sports implement having a male post with retention pins nested within an end of a sports implement.  
         [0014]    [0014]FIG. 5 illustrates a sports implement having a threaded socket on the end of the sports implement for receiving a male threaded post formed on a weight.  
         [0015]    [0015]FIG. 6 illustrates the use of a pair of friction rings on the joint surfaces between an attachment and a sports implement, with the sports implement shown in cross section and the attachment shown in profile.  
         [0016]    [0016]FIG. 7 illustrates the use of serrated surface features on the engagement faces between a weight and a sports implement.  
         [0017]    [0017]FIG. 8 illustrates an intermediate engagement device formed to allow the engagement features to be added to an attachment or sports implement rather than formed integrally with the attachment or sports implement. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]    In FIG. 1, wherein like numbers represent like elements, there is shown a sports implement  2  in the form of a baseball bat  4 . The sports implement may have a grip end  6  and a contact end  8 . A weight  10  or other attachment may be provided with a method for engaging the weight to the contact end of the sports implement. In the configuration shown in FIG. 1, the method for engaging comprises a receptacle  12  formed in the tip end  14  of the sports implement. The receptacle may be a bore  16  drilled into the end of the sports implement, allowing a cylindrical portion  18  of the weight  10  to be engaged within the bore  16 . A retention pin  20  or pins may be provided on the sidewall  22  of the cylindrical portion  18 . A retention channel  24  may be provided on a sidewall  26  of the bore  16 . The retention channel  24  may have a first leg  28  and a second leg  30 , and a portion  32  connecting the first leg  28  and the second leg  30 . The first leg may extend to an opening  34  in the end of the bore  16 , allowing a retention pin  20  to slide into the retention channel  24  when the cylindrical portion of the of the weight is engaged into the bore. An elastic element  38  such as a spring may be provided at the bottom of the bore to resist engagement of the cylindrical portion of the weight into the bore. The second leg  30  of the retention channel may be parallel to the first leg  28 , without extending to the opening  34 , such that the cylindrical portion of the weight and the retention pin may be forced into the bore, and then twisted to move the retention pin  20  into the second leg  30 . Alternatively, the second leg  30  may be orthogonal to the long axis of the sports implement, such that when the retention pins are in the second leg, such that the engagement faces ( 26 ,  28 ) remain in tight contact. The elastic element may then force the retention pin against the end of the second leg. As shown in FIG. 2, the weight may be formed such that it does not form a contact surface on the sports implement.  
         [0019]    As shown in FIG. 3, the bore  32  may be formed into the attachment, shown as a barrel extension  34 , with a cylindrical post section  36  extending from the sports implement  2 . An elastic element  38  may be provided around the periphery of the engagement end of the sports implement to both provide a biasing function for engagement of the retention pin  40  into the retention channel  42 , as well as to provide a smooth exterior contact surface  44 .  
         [0020]    As shown in FIG. 4, the attachment may be selected so as to have an outer diameter greater than the diameter of a pocket  402  on the end of the sports implement  2 . A post having retention pins  406  may be located in the pocket  402 , such that engagement of an attachment within the pocket  402  allows the attachment to nest within the end of the sports implement  2 . Alternately, the post  404  may be formed with male threads (not shown) on the exterior of the post, allowing an attachment having female threads to be threadedly engaged to the post  404 . A retention feature, such as a friction ring elastic element, or other device as described in this specification may be provided to ensure retention of the attachment onto the end of the sports implement.  
         [0021]    As shown in FIG. 5, the attachment  500  may be joined to the sports implement using a threaded connection  502 . The attachment  500  may form a portion of the contact surface  504  of the sports implement  2 , such that varying the length of the attachment  500  allows variation of the length of the sports implement  2 , as well as variation of the area of the contact surface  504  of the sports implement. A bore  506  may be drilled and tapped with female threads  508  in the end of the sports implement  2 . A retention ring  510 , such as a rubber gasket, may be provided adjacent to the periphery of a contact face to provide sufficient friction between the attachment  500  and the sports implement  2  to prevent the attachment  500  from rotating and loosening the threaded connection in an undesired fashion. The attachment  500  may be provided with surface features  512  such as grooves or knurling (not shown) to allow a stronger grip on the attachment when attaching or detaching the attachment  500  from the sports implement  2 .  
         [0022]    As shown in FIG. 6, when a bayonet fitting (retention pin and retention channel) is used for the connection between the attachment  600  and the sports implement  2 , care must be shown with regard to the design of the retention channel  602 . The retention pins  604  will exert a force against the retention channel  602  in an amount related to the mass of the weight and the speed and acceleration of the attachment  600 . Thus, the retention pins  604  must be of sufficient size and strength to prevent failure of the pins  604 , which could result in an undesired separation of the attachment  600  from the sports implement  2 .  
         [0023]    Furthermore, the design of the retention channel  602  must address the force generated by the acceleration of the weight on the end of the bat, which may tend to force the attachment  600  away from the sports implement  2 , creating a gap between the attachment  600  and the sports implement  2  where the attachment  600  is used to form a portion of the contact surface  606  of the sports implement  2 . The use of an L-shaped retention channel  608  allows the attachment to be snugly mounted against the sports implement  2 , but may not provide a positive detent to ensure retention of the attachment  600  to the sports implement  2 . A friction ring  610 , such as a thin rubber washer or a pair of rubber washers may be added to the end surfaces  612 ,  614  of the attachment  600  and/or sports implement  2  to improve the retention of the attachment  600  to the sports implement  2 . Alternately, serrated surface features  700 , such as shown in FIG. 7, may be implemented to provide a positive detent where the retention channel  702  is not shaped to provide such a detent. A serrated surface feature  704 ,  706  formed from an elastic material, such as a spring steel, rubber, or other elastomer, may be provided on contact faces on the attachment  700  and sports implement  2 . Engagement of the serrated surface features may require the two serrated surfaces to deform to allow rotation of the retention pins into the lateral legs of the retention channel, such that the contact between the serrated surfaces provides an anti-rotation force when the attached  700  is engaged to sports implement  2 . Proper design of the serrated surface features allows a tight joint to be accomplished, allowing the weight to form a portion of the contact surface without an undesirable gap being present between the attachment and the sports implement  2 . The serrations may be saw tooth or wave shaped.  
         [0024]    Although the engagement means has heretofore been illustrated as integral to the sports implement or to the attachment, the engagement means may be also formed through fabrication of an intermediary engagement device formed to be joined to the sports implement or to an attachment. As shown in FIG. 8, a male engagement device  802  may be provided with male threads  804  at one end and retention pins  806  at an opposite end. An attachment  800  may thus be formed with a bore  808  which is internally threaded  810  to receive the male engagement device  802 . This allows simpler forming tasks to be required to adapt the end of the sports implement  2  for engagement to an attachment  800 . Also, a female engagement device  810  may be formed having external threads  812 , and a central bore  814  having a retention through  816  and biasing element  818 , such as a spring. A sports implement  2  may thus be adapted for receiving the female engagement device  810  by drilling and threading  820  a bore in the engagement face  822  of the sports implement. The use of intermediate engagement devices  802 ,  810  may allow the implementation of attachments according to the present invention to sports implements which were previously manufactured, by allowing basic machining (drilling and threading) to be used to adapt the sports implement and/or attachment for implementation of attachments according to the present invention.  
         [0025]    As is apparent from the above description, the benefits of the present invention are not limited to baseball bats, but extend to other sports implements used to impact thrown or flying objects, such as, but not limited to, softball bats or cricket bats.  
         [0026]    The present invention may be embodied in other specific forms than the embodiments described above without departing from the spirit or essential attributes of the invention. Accordingly, reference should be made to the appended claims, rather than the foregoing specification, as indicating the scope of the invention.

Technology Classification (CPC): 0