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Tubular baseball bats with variable stiffened barrels

Tubular baseball bats with variable stiffened barrels description/claims

This is a continuation of U.S. application Ser. No. 10/672,060, filed on Sep. 29, 2003 (pending), the contents of which is herein incorporated by reference.

The present invention relates to baseball bats and more particularly to tubular baseball bats, constructed of a variety of materials, and more particularly to baseball bats designed to improve player performance as defined by greater hitting distance, and more particularly to baseball bats whose performance as defined by hitting distance is controlled by performance standards established by regulatory bodies.

Baseball and softball bats, hereinafter referred to simply as “baseball bats” or “bats”, are today typically made solely from aluminum alloys, or aluminum alloys in combination with composite materials (hybrid bats), or most recently solely from composite materials (with the exception of solid wooden bats for the Major Leagues). Such bats are tubular (hollow inside) in construction in order to meet the weight requirements of the end user, and have a cylindrical handle portion for gripping, a cylindrical barrel portion for striking, and a tapered mid-section connecting the handle and barrel portions. Such bats have constant stiffness along their barrel portion length.

When aluminum alloys initially replaced wooden bats in most bat categories, the original aluminum bats were formed as a single member, that is, they were made in a unitary manner as a single-walled aluminum tube for the handle, taper, and barrel portions. Such bats are often called single-wall aluminum bats and were known to improve performance relative to wooden bats as defined by increased hit distance. More recently (in the mid 1990's), improvements in bat design largely concentrated on further improving bat performance. This was accomplished primarily by thinning the barrel or hitting portion of the bat frame and adding inner or internal, and or outer or external, secondary members extending along the entire barrel length; these members are often referred to respectively as inserts or sleeves; while the main member is often referred to as a body, shell or frame in the prior art. Such bats are often called double-wall bats or multi-walled bats in the case of more than two walls.

The prior art of such double walled and multi-walled tubular bats generally refer to improved performance or hit distance resulting from trampoline effect, spring, compliance, rebound, flexibility, etc. resulting from the multi-wall two or more member construction along the entire barrel length allowing the barrel portion of the bat to deflect or flex more upon ball impact which propels the ball faster and further than prior art bats. The scientific principle governing improved bat performance is bending theory. When a ball impacts a bat it has kinetic energy that must be absorbed by the bat in order to stop the ball. The bat stores this energy by flexing. After the ball is stopped, the bat returns the energy it stored by rebounding and sending the ball back towards where it came from. The more the bat barrel or striking portion deforms upon ball impact without failing (denting or breaking), the lower the energy loss in the ball, and the greater the energy return to the ball from the bat as the tubular bat barrel portion impacted returns to its original shape. To allow the bat barrel portion to deform, requires lowering the radial stiffness of the barrel portion. The prior art double walled and multi-walled tubular bats accomplish this by thinning the main member barrel portion and adding thin secondary member insert(s) and/or sleeve(s) which are not joined to the main member, extend full length of the barrel portion, and result in lowered constant stiffness along the barrel portion.

U.S. Pat. No. 5,303,917 to Uke discloses a two member bat of thermoplastic and composite materials.

U.S. Pat. No. 5,364,095 to Easton discloses a two member bat consisting of an external metal tube and an internal composite sleeve bonded to the inside of the external metal tube and running full length of the barrel portion of the bat.

U.S. Pat. No. 6,322,463B1 to Chauvin discloses the method of tuning a unitary member all composite bat.

U.S. Pat. No. 5,415,398 to Eggiman discloses a two member metallic bat consisting of a frame and internal insert of constant thickness running full length of the barrel portion of the bat in a double-wall construction. Further, U.S. Pat. Nos. 6,251,034B1 and 6,482,114B1 disclose variations to U.S. Pat. No. 5,415,398. Further, U.S. Pat. No. 6,251,034B1 discloses a polymer composite second tubular member running full length of the barrel portion of the bat with the members joined at the ends only of the barrel portion with the balance of the composite member freely movable relative to the primary member. U.S. Pat. Nos. 6,440,017B1 and 6,612,945 B1 to Anderson also disclose two member bats with an outer sleeve and inner shell of constant thickness running full length of the barrel portion.

U.S. Pat. No. 6,063,828 to Pitzenberger discloses a two member bat consisting on an internal body and an external shell of constant thickness running full length of the barrel portion in a double-wall construction. U.S. Pat. No. 6,461,760B1 to Higginbotham discloses the bat of U.S. Pat. No. 6,053,828 with a composite shell formed to an outer shell running full length of the barrel portion of the bat.

Similarly, U.S. Pat. No. 6,425,836B1 to Mizuno discloses a two member bat with a lubricated coating between layers or a weak boundary layer formed on the surfaces of the inner member.

U.S. patent Pub. 2001/0094882 A1 by Clauzin discloses a two member bat consisting of an outer shell and an insert laminate partially bonded to the shell.

In all prior art multi-walled tubular bats, the bat frame primary and secondary members extend along the entire barrel length and are of constant thickness. Also, the bat members are not joined, except at their ends, in order to reduce radial stiffness of the barrel portion to improve bat performance. Also, in all cases, the radial stiffness of the barrel portion is uniform or constant full length of the barrel portion of the bats.

While the prior art single member, and more particularly, double-walled and multi-walled tubular bats have demonstrated improved performance as claimed, various regulatory bodies have raised safety concerns regarding improved performance bats and thus, some have established maximum performance standards for various categories of baseball bats under their jurisdiction. As a result, manufacturers of baseball bats are required to pass various controlled laboratory tests, such as, bbf (batted ball performance), bbs (batted ball speed), etc. Further, for a given bat category (e.g. slowpitch softball), there may be two or more regulatory bodies each of which may establish a different standard. Further, any of the regulatory bodies may change their standard from time to time. Such new or changed or varying regulations are extremely problematic, costly, and disruptive for both manufacturers and players.

The one solution to the problem of lowering performance of the prior art bats in order to meet new or changed performance standards is to increase thickness full length of one or more of the barrel members, and/or the single wall bat frame, which increases radial stiffness thus reducing performance. The increased wall thickness solution of the prior art tubular bats applied along the entire barrel length of either the main member frame and/or secondary barrel members can increase weight such that the finished bat weight standard or objective is exceeded and thus, the bat in question is obsolete. This results in costly inventory write-offs for the manufacturer while individual players must replace an otherwise good bat with a new bat which meets the current standards. Further, the manufacturer incurs significant redesign and retooling costs and marketing timing issues (i.e. for at least a period of time, have no bat which meets the new standard).

Therefore, what is needed is a simple, low cost invention to decrease bat performance of tubular bats in a controlled manner, in order to meet lowered or changed bat performance standard requirements without significantly increasing bat weight. Further, what is needed is that such an invention can be employed for both new bats being manufactured and used bats returned from players (to be returned to players with lowered performance to meet the new or changed standard involved). Further, what is needed is the required performance decrease at least partially be offset by improving another bat characteristic such as “sweetspot” (barrel portion length of maximum bat performance) size. Also, what is needed is newly designed tubular bats with a predetermined bat performance with larger sweetspot areas than bats of the prior art.

Therefore, in view of the foregoing, what is needed is tubular baseball bats with variable stiffness along their barrel portions. A main object of the present invention is to provide tubular baseball, and particularly existing bats, with changed (usually decreased) bat performance, without significantly increased weight, in order to meet new or changed performance standards. To achieve this, the bats of the present invention are stiffened in the barrel area of peak bat performance commonly referred to as the sweetspot. Typically, this is an area approximately 2″ to 4″ in width as compared to barrel portion lengths of 4″ to 16″. This is achieved by inserting or adding to the bat a circumferential stiffener in the region of the sweetspot.

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• Utility Patent

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