Patent Application
20160279492
During a collision between a bat and a ball, a portion of energy is stored in vibrational modes of the bat, including energy stored by radial deformation or local compression of the bat at the site of the collision. This stored energy is largely returned to the ball, translating to the ball exit speed, or rebound velocity. This effect is typically referred to as the “trampoline effect.” The trampoline effect is directly proportional to the bat-ball coefficient of restitution (“BBCOR”). Thus, as the BBCOR increases, the trampoline effect is enhanced, resulting in a higher rebound velocity.
A ball bat includes a barrel having one or more slats. The slats may be separated from one another by one or more apertures, cuts, or gaps. The slats may be oriented substantially parallel, substantially transverse, or substantially diagonal to a longitudinal axis of the barrel. The slatted arrangement enhances the BBCOR of the barrel. An external damping sleeve or an internal reinforcing core may be included in the barrel to limit the barrel's BBCOR to meet given regulatory standards. Other features and advantages will appear hereinafter. The features described above can be used separately or together, or in various combinations of one or more of them.
In the drawings, wherein the same reference number indicates the same element throughout the views:
Various embodiments of the invention will now be described. The following description provides specific details for a thorough understanding and enabling description of these embodiments. One skilled in the art will understand, however, that the invention may be practiced without many of these details. Additionally, some well-known structures or functions may not be shown or described in detail so as to avoid unnecessarily obscuring the relevant description of the various embodiments.
The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this detailed description section.
Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of items in the list. Further, unless otherwise specified, terms such as “attached” or “connected” are intended to include integral connections, as well as connections between physically separate components.
Turning now in detail to the drawings, as shown in
The ball bat 10 is preferably constructed from one or more composite or metallic materials. Some examples of suitable composite materials include fiber-reinforced glass, graphite, boron, carbon, aramid, ceramic, Kevlar, Astroquartz®, or any other polymer matrix composite that includes a combination of unidirectional fiber layers, woven layers, and braided layers. Aluminum or another suitable metallic material may also be used to construct the ball bat 10. A ball bat including a combination of metallic and composite materials may also be constructed. For example, a ball bat having a metal barrel and a composite handle, or a composite barrel and a metal handle, may be used in the embodiments described herein.
The ball bat 10 may have any suitable dimensions. The ball bat 10 may have an overall length of 20 to 40 inches, or 26 to 34 inches. The overall barrel diameter may be 2.0 to 3.0 inches, or 2.25 to 2.75 inches. Typical ball bats have diameters of 2.25, 2.625, or 2.75 inches. Bats having various combinations of these overall lengths and barrel diameters, or any other suitable dimensions, are contemplated herein. The specific preferred combination of bat dimensions is generally dictated by the user of the bat 10, and may vary greatly between users.
The ball striking area of the bat 10 typically extends throughout the length of the barrel 14, and may extend partially into the tapered section 16 of the bat 10. For ease of description, this striking area will generally be referred to as the “barrel” throughout the remainder of the description. A bat barrel 14 generally includes a maximum performance location or “sweet spot,” which is the impact location where the transfer of energy from the bat 10 to a ball is maximal, while the transfer of energy to a player's hands is minimal. The sweet spot is generally located at the intersection of the bat's center of percussion (COP) and its first three fundamental nodes of vibration. This location, which is typically about 4 to 8 inches from the free end of the barrel 14, does not move when the bat is vibrating in its first (or fundamental) bending mode.
A variety of integral barrel features or configurations that modify the barrel's BBCOR are described below. The specific type, size, or configuration of the one or more BBCOR-modifying features used in a given bat may be dictated by the performance limits of a given regulatory association, the weight and feel preferences of a given batter, and so forth. Depending on the design goals for a particular bat, one or more of the following features may be utilized at one or more locations of the ball bat 10.
In one embodiment, the barrel 14 includes one or more strips or slats separated by one or more apertures, cuts, or gaps (referred to hereinafter generally as “apertures,” for ease of reference), resulting in a “slatted barrel”. This slatted configuration enhances spring-like compression of the barrel wall when it contacts a baseball, thus decreasing the barrel's circumferential stiffness. This decrease in circumferential stiffness results in an increased BBCOR.
As shown in
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According to some embodiments, the ball bat 10 includes one or more features for limiting the BBCOR of the barrel 14 so that it to complies with performance limitations imposed by baseball or softball governing bodies. Limiting the BBCOR in a bat may be accomplished in several ways, including thickening the barrel wall, increasing the radial stiffness of the barrel via the inclusion of specific materials, components, or fiber angles, or damping the barrel to reduce its hoop frequency.
As shown in
The damping sleeve 50 may be positioned along the outer surface of the barrel 14, in direct contact with the slats 22, or, in the case where the slats 22 are enveloped by an encasement 40, the damping sleeve 50 may be positioned along the outer circumference of the encasement 40. In some embodiments, a damping sleeve 50 may be permanently adhered to the slats 22 or encasement 40. In other embodiments, the damping sleeve 50 may be removable, such that any slatted bat barrel may be fitted with a damping sleeve 50 suitable to bring the bat within the performance limits of a given association or level of play.
The damping sleeve 50 may partially or completely cover the slatted region of the barrel 14. In some embodiments, the damping sleeve 50 may extend beyond the slatted region to provide additional damping. In other embodiments, the damping sleeve 50 may be located substantially at or near the sweet spot of the barrel 14, such that it covers only a portion of the slatted region of the barrel 14.
As shown in
In some embodiments, the stiffening core 60 may act as a second wall of the barrel. The barrel may include, for example the slatted wall—with or without an encasement 40—and the stiffening-core wall. These walls may optionally be separated from each other by one or more interface shear control zones (“ISCZs”), as described in detail in U.S. Pat. No. 7,115,054, which is incorporated herein by reference. An ISCZ may include, for example, a disbonding layer or other element, mechanism, or space suitable for preventing transfer of shear stresses between neighboring barrel walls. A disbonding layer or other ISCZ preferably further prevents neighboring barrel walls from bonding to each other during curing of, and throughout the life of, the ball bat 10.
In some embodiments, a damping sleeve 50 and a stiffening core 60 may both be included in a bat barrel. In such an embodiment, the materials chosen for, and the thickness of, each of these components may be varied to meet given BBCOR requirements. Each or both of these components 50, 60 may optionally be used in a slatted barrel including an encasement 40, or in a slatted barrel that does not include an encasement 40.
Any of the above-described embodiments may be used alone or in combination with one another. Furthermore, the ball bat may include additional features not described herein. While several embodiments have been shown and described, various changes and substitutions may of course be made, without departing from the spirit and scope of the invention. The invention, therefore, should not be limited, except by the following claims and their equivalents.
