Abstract:
A barrel for a ball bat having a first inside surface and an outside surface, and a first thickness represented by the distance between the first inside surface and the outside surfaces. The first thickness of the barrel is generally uniform except at one or more locations within the ball impact area of the bat. However, the barrel may include one or more than one thick section relative to the uniform thickness of the rest of the barrel of the bat. In addition, the barrel may include one or more than one thin section relative to the uniform thickness of the rest of the barrel of the bat. The shoulders between the thick and/or thin section(s) and the uniform thickness of the remainder of the bat may be relatively abrupt.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. U.S. 62/365,845, filed Jul. 22, 2016, which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to an aluminum bat for use in diamond sports such as baseball and softball. More particularly, the present invention relates to a bat with a variable wall thickness. 
       BACKGROUND OF INVENTION 
       [0003]    Numerous attempts have been made to improve the performance of a bat. These prior attempts have included the addition of various shells, inserts, materials, and shapes of the bat in order to improve its performance or usage. For example, U.S. Pat. Nos. 7,867,114, 7,014,580, 6,949,038, 6,761,653 6,733,404, 6,663,517, 6,497,631, 6,398,675, 6,176,795, 6,022,282, 4,930,772, 4,331,330, and 3,990,699, and U.S. Patent Application Publication Nos. 2002/0016230, 2002/0091022, 2005/0070384, 2010/0160095, 2011/0152015, 2013/0274039, 2013/0165279, and 2015/0273295 disclose various attempts to improve the performance or use of a bat. 
         [0004]    The performance of a bat is generally based upon the weight of the bat, length of the bat, and the impact response of the bat at and during impact with a ball. Thus, bats are often discussed in terms of “weight drop.” The weight drop of a bat is the difference between the bat&#39;s length (in inches) and its weight (in ounces). For example, a 30 inch bat that is considered a “−8” would have a weight of 22 ounces (i.e., 30 inches minus 22 ounces equals −8). 
         [0005]    Most of the focus for improvements in bat technology has been in improving the performance of the ball impact area of the bat. The ball impact area itself may be many inches in length, depending on the construction of the bat. The ball impact area generally includes a point of maximum performance, at which a batted ball leaves the bat with the highest exit velocity compared to the rest of the ball impact area of the bat. The point of maximum performance is often approximately four to eight inches, and usually five to seven inches, from the end cap end of the bat barrel. 
         [0006]    The ball impact area generally encompasses the portion of the barrel having a constant outer diameter as well as the portion of the barrel that tapers. The portion of the barrel having a constant outer diameter is referred to herein as the barrel portion of the barrel, which generally extends from the end-cap to where the outer diameter of the barrel begins to taper. The portion of the barrel that tapers is referred to herein as the transition section of the barrel, and typically extends from the barrel portion to the handle, or thereabouts. 
         [0007]    As prior art bats have increased the performance in this area, many sports regulatory agencies have placed performance and/or configuration restrictions on the bats. For example, most regulatory bodies set a maximum performance level of a bat when a ball impacts the point of maximum performance of that bat. Typically, this impact performance level is measured by the exit velocity of the ball off the bat right after impact. 
         [0008]    Historically, the performance of a bat in the ball impact area adjacent to point of maximum performance of that bat show significant reductions in performance. Such a prior art curve is shown in  FIG. 1 . The y-axis of the graph in  FIG. 1  is the performance number (with a higher number signifying better performance), while the x-axis represents the location along the ball impact area of the bat at which the corresponding performance number was obtained. As can be seen, although the prior art bat&#39;s (which is a −3.68 bat) performance peaks as expected at the point of maximum performance, the bat&#39;s performance falls off quite rapidly. By reducing the performance of the bat at the point of maximum performance, the bat&#39;s performance adjacent the point of maximum performance is reduced even further. 
         [0009]    The contemporary bat art has made few attempts to improve the performance of the bat sections adjacent the point of maximum performance. As such, the performance of the bats in areas distal from, and even adjacent to, the point of maximum performance dramatically drops for conventional bats. Prior art attempts to address these issues have drawbacks. For example, inserts may be positioned inside of the barrel of a bat. These inserts may be metal rings that are glued or otherwise secured inside the barrel. Such rings may alternatively be made of composite materials, and may be molded and/or cured within the barrel in a secondary process. Such rings can result in heavier bats that take longer to construct. 
         [0010]    Thus, there is a continuing need for improved overall performance of bats. These improved bats need to conform to the regulatory agencies&#39; restrictions for in the preferred hitting zone while performing well at locations that are longitudinally outside the preferred hitting zone. These improved bats preferably increase the performance in locations adjacent the preferred hitting area/zone as compared to the preferred hitting zone. These improved bats, or features of a bat, are lacking in the art. 
       SUMMARY OF THE INVENTION 
       [0011]    Disclosed herein is a barrel of a ball bat for striking a ball. The bat itself may comprise an axis, a handle (not shown), and the barrel. The handle may include an attachment end and a knob end. The barrel includes a ball impact area formed by a barrel portion and a transition section. The handle may be of unitary construction with the barrel, or may be attached to the barrel according to known prior art techniques and structures. In either case, the transition section of the barrel is operatively attached to the attachment end of the handle at an attachment end of the transition section. A point of maximum performance is located within the ball impact area along the barrel. The barrel may also include an end cap. 
         [0012]    The barrel has a first inside surface and an outside surface, and a first thickness represented by the distance between the first inside surface and the outside surfaces. In an example embodiment, the first thickness of the barrel is generally uniform except at one or more locations within the ball impact area of the bat. As a non-limiting example, the barrel may include one or more than one thick section relative to the uniform thickness of the rest of the barrel of the bat. In addition, in an example embodiment, the barrel may include one or more than one thin section relative to the uniform thickness of the rest of the barrel of the bat. The shoulders between the thick and/or thin section(s) and the uniform thickness of the remainder of the bat may be relatively abrupt. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0013]    For a better understanding of the various embodiments of the present invention, reference may be made to the accompanying drawings in which: 
           [0014]      FIG. 1  is a graph showing the performance of a prior art aluminum bats; 
           [0015]      FIG. 2  is a cross sectional view of an example embodiment of a bat with variable wall thickness; 
           [0016]      FIG. 3 . is a chart showing combinations of example characteristics for several example bats in accordance herewith. 
           [0017]      FIG. 4  is a graph showing example performance of bats with variable wall thickness as compared to a prior art aluminum bat. 
       
    
    
       [0018]    While the disclosure is susceptible to various modifications and alternative forms, a specific embodiment thereof is shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description presented herein are not intended to limit the disclosure to the particular embodiment disclosed, but to the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures. 
         [0020]    Referring to the drawings,  FIG. 2  illustrates a portion a ball bat  100 , which is preferably made from aluminum. Specifically, a barrel  105  is shown, which preferably includes a transition section  110  and a barrel portion  115 . The transition section  110  connects to a handle portion (not shown) at an attachment end of the transition section  110  according to structures and methods known in the art. For example, the transition section  110  may be integrally formed with the handle, or may be a separate piece that is affixed to the handle. The barrel portion  115  may extend substantially from the transition section  110  to the end-cap end  120  of the ball bat  100 . The barrel portion  115  and transition section  110  for the ball impact area of barrel  105 . The ball impact area preferably encompasses a point of maximum performance therealong. 
         [0021]    As shown in  FIG. 2 , the transition section  110  (and/or the section of the barrel portion  115  proximate the transition section  110 ) preferably has an outer surface  125  and a first inner surface section  130 . The distance between the first inner surface section  130  and the outer surface  125  comprises a first thickness. 
         [0022]    As shown in  FIG. 2 , one or more than one thick section  135  may be positioned along the ball impact area. As shown in  FIG. 2 , a thick section  135  is shown positioned in the barrel portion  115 , although it should be noted that a thick section  135  could be positioned along the transition portion  110  of the barrel. In an example embodiment, a thick section  135  may be positioned at or about the point of maximum performance, although other locations are envisioned. The thickness of the thick section  135  of  FIG. 2 , as illustrated, extends between outer surface  125  and a second inner surface section  140 . The second inner surface section  140  is positioned radially inward from the first inner surface section  130 , which yields a second thickness that is larger than the first thickness. Shoulders  145  allow for a continuous transition between different thicknesses of the barrel. For example, in  FIG. 2 , shoulder  145 A provides for a transition between the first and second thicknesses. 
         [0023]    One or more than one thin section  150  may also be positioned along the ball impact area. In an example embodiment, a thin section  150  may be positioned adjacent to a thick section  135 . The thickness of the thin section  150  of  FIG. 2 , as illustrated, extends between outer surface  125  and a third inner surface section  155 . The third inner surface section  155  is positioned radially outward from the first inner surface section  130 , which yields a third thickness that is smaller than the first thickness. In  FIG. 2 , shoulder  145 B provides for a transition between the second and third thicknesses. Each shoulder  145  is preferably less than or equal to about 0.5 inches in length. However, it is noted that longer bats  100  and/or large ratios between second and third thicknesses (discussed below) may result in longer lengths for shoulders  145 . The use of one or more thick sections  135  allow the performance of the barrel  105  to stay under various performance thresholds set by various agencies. 
         [0024]    It is noted that a bat  100  may contain any number of thick and thin sections  135 ,  150 , and such sections may be positioned anywhere along the ball impact area of the bat  100 . The structure of  FIG. 2  is one example, but in other non-limiting examples, a thin section  150  may reside between a thick section  135  and the transition section  110  of bat  100 . Additionally, a thin section  150  may reside between two thick sections  135 , or a thick section  135  may reside between two thin sections  150 . A thin section  150  may extend to the end-cap end  120  of the bat, or the barrel  105  may have the first thickness proximate the end-cap end  120 . 
         [0025]    In an example embodiment, a thin section  150  has a thickness of between about 0.065 inches and 0.120 inches, and preferably between about 0.075 inches and 0.100 inches. It is also noted that a thin section  150  may actually have the first thickness, so long as it is thinner than the thick section  135 . However, additional weight savings and performance gains may be achieved with a third thickness that is smaller than the first thickness. For example, weight drops of −5 or more, and preferably of −8 to −10 are preferable. Prior art structures have achieved weight drops of only around −3, which are not as desirable. 
         [0026]    In an example embodiment, a thick section  135  has a thickness of between about 0.170 and 0.200 inches. In an example embodiment, a preferred ratio of the second thickness to the third thickness is greater than 1.600, and more preferably between about 1.700 and 2.270. 
         [0027]    In an example embodiment, the length of the barrel portion  115 , which preferably has a generally constant outer diameter, is between about three and eight inches, while a length of a thick section  135  (not including shoulders  145 ) is between about one and two inches (and preferably between 1.5 and 2 inches). The ratio between the length of the barrel portion  115  and the length of a thick section  135  (not including shoulders  145 ) is preferably between about 1.5 and 5.67, in an example embodiment. The ratio between the length of a thick section  135  (not including shoulders  145 ) and the second thickness is preferably between about 8.11 and 11.76, in an example embodiment. The ratio between the length of the barrel portion  115  and the second thickness is preferably between about 17.65 and 50.00.  FIG. 3  is a chart showing various characteristics of five example bats. 
         [0028]      FIG. 4  is a graph similar to  FIG. 1 , showing a normalized comparison between the prior art plot of a prior art bat from  FIG. 1 , as compared to bats having variable wall thicknesses as described herein. As can be seen, the prior art −3.68 bat (denoted by circles) has peak performance at the point of maximum performance, but falls off quick quickly as discussed above. However, two examples of bats in accordance with the teaching hereof show very different curves. One bat (denoted by squares) utilizing thick/thin sections  135 / 150  as taught here achieves a −7.62. Further, this structure significantly raises the performance of the barrel adjacent the point of maximum performance (relative to the bat&#39;s performance at the point of maximum performance). Another bat (denoted by triangles) achieves a −8.99, and shows even better performance adjacent the point of maximum performance. In general, the performance of the bat at locations spaced outwardly from the point of maximum performance is dramatically increased relative to the bat&#39;s performance at its point of maximum performance. 
         [0029]    From the foregoing, it will be seen that the various embodiments of the present invention are well adapted to attain all the objectives and advantages hereinabove set forth together with still other advantages which are obvious and which are inherent to the present structures. It will be understood that certain features and sub-combinations of the present embodiments are of utility and may be employed without reference to other features and sub-combinations. Since many possible embodiments of the present invention may be made without departing from the spirit and scope of the present invention, it is also to be understood that all disclosures herein set forth or illustrated in the accompanying drawings are to be interpreted as illustrative only and not limiting. The various constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts, principles and scope of the present invention. 
         [0030]    As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.” 
         [0031]    Many changes, modifications, variations and other uses and applications of the present constructions will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.