US20180250565A1

US20180250565A1 - Variable wall composite bat

Info

Publication number: US20180250565A1
Application number: US15/910,205
Authority: US
Inventors: Peter Wiese
Original assignee: Rawlings Sporting Goods Co Inc
Current assignee: Rawlings Sporting Goods Co Inc
Priority date: 2017-03-03
Filing date: 2018-03-02
Publication date: 2018-09-06

Abstract

A composite ball bat comprising a handle, a tapered portion extending from an attachment end of the handle, and a barrel portion extending from the tapered portion to an end-cap end. The barrel portion includes an inner surface and an outer surface, with a uniform thickness between the inner and outer surfaces. The barrel portion also includes a preferred impact area. At least one increased-thickness section is molded and cured integrally with the barrel portion. That composite material forming the barrel portion and at least one increased-thickness section is therefore uniform. At least one of the increased-thickness sections is positioned at or near the preferred impact area, and each increased-thickness section has a thickness greater than the uniform thickness.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is claiming priority to U.S. Provisional Application Ser. No. 62/466,470 filed Mar. 3, 2017, the entire disclosure of which is incorporated herein by reference.

FIELD OF INVENTION

The present invention relates generally to a composite bat for use in diamond sports such as baseball and softball. More particularly, the present invention relates to a composite bat with a variable wall thickness. The various thicknesses are simultaneously molded into the bat, resulting in a generally uniform composite material throughout the various thicknesses.

BACKGROUND OF INVENTION

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.
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. Most of the focus for improvements in bat technology has been in improving the performance of the preferred impact area, or “sweet spot” of the bat. The sweet spot may be many inches in length, depending on the construction of the bat. The sweet spot 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 sweet spot 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.
As the 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, even as the bat “breaks in” during use. Typically, this impact performance level is measured by the exit velocity of the ball off the bat right after impact. Additionally, bats must break at a certain point during testing (e.g., accelerated break in rolling) in order to pass tests imposed by sports regulatory agencies. As bats tend to increase in performance as they “break in,” some competitors sacrifice much of the lifetime of the bat by intentionally aging or damaging their bats to increase performance. Sports regulatory agencies therefore often test bats by “rolling” them through rollers that exert high pressures. Bats must fully fail during these tests to show that artificial aging/damaging techniques would not be effective.
Historically, the performance of a bat in the sweet spot 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 is the performance number (with a higher number signifying better performance), while the x-axis is the location along the sweet spot of the bat. As can be seen, although the prior art bat's performance peaks as expected at the point of maximum performance, the bat's performance falls off quite rapidly. By reducing the performance of the bat at the point of maximum performance, the portions of the sweet spot adjacent the point of maximum performance are reduced even further. The contemporary bat art has made few attempts to improve the performance of the bat's sweet spot adjacent the point of maximum performance.
For example, prior art composite bats are often molded and/or cured between inner and outer forms which define the inside and outside surfaces of the barrel of the bat. Inserts may then be positioned inside of barrel. 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, well after the barrel itself is molded and cured. This extended process may result in a fully composite bat, but with inconsistent and nonhomogeneous composite rings as compared to the barrel itself.
Thus, there is a continuing need for improved overall performance of bats. These improved bats need to conform to the regulatory agencies' restrictions for in the point of maximum performance while performing well at locations that are longitudinally adjacent to and away from point of maximum performance. 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

Disclosed herein is a bat for striking a ball. The bat comprises an axis, a handle, and a barrel. The handle includes an attachment end and a knob end. The barrel includes a barrel portion having a barrel length, 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. The sweet spot of the bat is preferably positioned along the barrel portion. The barrel may also include an end cap.
The barrel has an inside surface and an outside surface, and a thickness represented by the distance between the inside and outside surfaces. In an example embodiment, the thickness of the barrel is generally a uniform thickness except at or near the sweet spot of the bat, and preferably at or near the point of maximum performance. As a non-limiting example, the barrel may include one or more than one section with increased thickness relative to the uniform thickness of the rest of the barrel of the bat. The transition between the section(s) with increased thickness and the uniform thickness of the bat may be relatively abrupt. In an example embodiment, the barrel may transition from the uniform thickness up to its increased thickness within approximately 0.080 inches and 0.140 inches. In an examplembodiment, the transition may occur over approximately 0.100 inches.
The barrel may be composed of a composite material. In an example embodiment, the increased-thickness section(s) is/are molded and/or cured simultaneously with the rest of the barrel to create a generally uniform composite composition throughout the barrel. A relatively standard outer mold section may be used to form the outside surface of the barrel. However, a selectively inflatable bladder is preferably used to form the inside surface of the barrel, such that the inner surface of the barrel is complete with increased-thickness sections. The bladder may have a shape that generally mimics the inner surface of the barrel, minus the increased-thickness section(s). However, because an inflatable bladder is used instead of a fixed internal mold, the increased-thickness section(s) is/are accommodated by the bladder, even when inflated with pressure during curing. The bladder therefore molds to the internal shape of the barrel upon inflation. Alternatively the bladder may have one or more indentations that correspond to the increased-thickness section(s). The bladder, when selectively deflated, allows for removal of the cured bat from its mold.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the various embodiments of the present invention, reference may be made to the accompanying drawings in which:

FIG. 1 is a graph showing the performance of a prior art composite bats;

FIG. 2 is a cross sectional view of a prior art bat within a prior art old;

FIG. 3 is a cross sectional view of an example embodiment of a composite bat with variable wall thickness;

FIG. 4 is a detailed cross sectional view of the barrel portion of the bat of FIG. 3 focusing on the area surrounding the sweet spot of the bat.

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 INVENTION

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.
Referring to the drawings, FIG. 2 illustrates a prior art external mold section 105 and internal mold section 110, with a prior art barrel 115 therebetween. The barrel 115 includes a barrel portion 120 and a tapered portion 125. In FIG. 2, the barrel 115 is shown to be separated by a gap from the mold sections 105, 110. This gap is shown merely to better illustrate the barrel 115 as a separate component from the mold sections 105, 110. In actuality, little or no gap is likely to be present. This is also true of FIG. 3, discussed below.
The barrel 115 has a generally uniform thickness 130 defined between an outer surface 135 and an inner surface 140. As will be understood, once molded and cured, the internal mold section 110 is easily removeable from within the barrel 115 through the open end cap end 145 of the barrel 115. Alternatively, the barrel 115 may be removed from the mold sections 105, 110, although in any case the internal mold section 110 passes through the open end cap end 145 of the barrel 115.
FIG. 3 illustrates an example embodiment of a composite barrel 215 according to the present invention. The barrel 215 is positioned between an external mold section 105 and a modified internal mold section 210. As in FIG. 2, the barrel 215 includes a barrel portion 220 and a tapered portion 225, and again has a generally uniform thickness 230 as measured between outer surface 235 and inner surface 240. The barrel 215 similarly includes an open end-cap end 245. However, barrel 215 also includes two increased-thickness sections 250 positioned along the sweet spot of the bat. As will be understood, various numbers and positions increased-thickness sections 250 are envisioned. In an example embodiment, an increased thickness section 250 is positioned at the point of maximum performance. In an alternative example embodiment, an increased thickness section 250 is positioned proximate the point of maximum performance, either toward the open end-cape end 245 or toward the tapered portion 225, or both. In an example embodiment, an increased thickness section 250 is positioned approximately three to eight inches from the end-cap end 245, depending on the length of the bat and other factors.
The modified internal mold section 210 differs from the inner mold section 110 of FIG. 2 in that the modified internal mold section 210 is an inflatable bladder. Although in an example embodiment the bladder 210 has generally the same shape as the prior art inner mold section 110, it accommodates any increased-thickness sections 250 on the inner surface 240 because it is inflatable. As shown in FIG. 3, the bladder 210 is able to contour to the increased-thickness section 250 when inflated.
A solid inner mold (such as inner mold 110) would be incapable of accommodating the increase-thickness sections. A solid inner mold would need cutouts corresponding to any increased-thickness section 250. Such cutouts in a solid inner mold 110 would make removal of the inner mold extremely difficult. Each increased-thickness section 250 would engage with its corresponding recess in the solid inner mold, thereby preventing axial movement of the solid internal mold section relative to the barrel 215. This would hinder a solid internal mold 210 from being pulled through the open end-cap end 245.
In the prior art, if a ring (composite or otherwise) was desired within the barrel 115, any such rings would be fitted into the barrel 115 after the barrel 115 had been cured. In the case of a composite ring, the composite ring would itself have to be molded and cured inside the barrel 115, but only after the barrel 115 had already been molded and cured. The result is a bat with inconsistent internal composition between the composite ring and the rest of the barrel 115, due to the different curing steps. This also results in an extra step.
Use of an inflatable bladder 210 as the modified internal mold section 210 avoids these issues. The barrel 215 may be formed with one or more increased-thickness sections 250 at the time of molding the barrel 215, itself. A single curing step follows, in which the inflatable bladder 210 is inflated to mold to the inside of the barrel 215 and any increased-thickness sections 250 therein. Sections 255 of the inflatable bladder 210 having molded around the increased-thickness sections 250 are shown in FIG. 3. This single curing step results in a uniform and consistent internal composition of the barrel 215 and increased-thickness section(s) 250. Molding and curing the increased-thickness sections 250 along with the rest of the barrel 215 thereby avoids the extra step and inconsistent composition of the prior art. The result is a bat with consistent composition through the barrel 215 and increased-thickness sections due to the common molding step.
When finished, the bladder 210 is deflated to allow for removal of the barrel 215. Preferably, the bladder 210 is formed from a material capable of withstanding a molding and/or curing process while inflated, but conforming to the contours of the increased-thickness sections 250. The bladder 210 may be inflated to an internal pressure of approximately 100-180 PSI, although other pressures are contemplated. The bladder 210 may be a straight or constant diameter bladder, or a net shaped bladder, or the like. In an alternative embodiment, the selectively inflatable bladder 210 may itself include one or more recesses 250 structured therein.
The internal structure of barrel 215 can thereby be molded and cured with one or more than one integral increased-thickness section 250. The increased thickness sections 250 may be made from composite materials having constituent matrix components with different angles as the rest of the barrel 215. In a non-limiting example, a barrel may use 45-degree reinforcement components, while the increased-thickness sections may utilize 55-degree reinforcement components. Even so, as the increased-thickness sections 250 are molded and cured at the same time as the rest of the barrel 215, the composition of barrel 215 is therefore consistent (within manufacturing tolerance) between sections having the generally uniform thickness 230 and the increased-thickness sections 250.
FIG. 4 illustrates a detailed cross sectional view of the barrel portion 225 of barrel 215 of FIG. 3, focusing on the area surrounding the point of maximum performance. In addition to the uniform thickness 230 of the barrel 215, the increased-thickness sections 250 have an increased thickness 305, which is larger than the generally uniform thickness 230. In a non-limiting example embodiment, the generally uniform thickness 230 is between approximately 0.110 inches and 0.140 inches, and is preferably about 0.125. In a non-limiting example embodiment, the increased thickness 305 is between approximately 0.300 inches and 0.400 inches, and is preferably about 0.350 inches.
An example increased-thickness section 250 may include at least one shoulder 310. A shoulder 310, as shown in FIG. 4, is an area of increasing or decreasing thickness of the barrel 215, between the uniform thickness 230 and the increased thickness 305. In prior art structures in which composite rings are separately molded/cured into an existing composite barrel 115, the shoulder is typically relatively long. However, by using a selectively inflatable bladder 210 to help mold and cure the increased-thickness sections 250 at the same time as the rest of the barrel 215, the thickness of the barrel 215 changes over a relatively short distance at a shoulder 310. In a non-limiting example embodiment, a shoulder 310 is between approximately 0.080 inches and 0.140 inches, and is preferably about 0.100 inches.
The abrupt increase/decrease in the thickness of barrel 215 between the uniform thickness 230 and the increased thickness 305 creates stress concentrations on the barrel 215 when it is subjected to various performance test procedures like ABI rolling. These stress concentrations weaken the barrel 215 and ultimately allow it pass performance test procedures by completely failing or breaking apart during testing. However, during actual play, these stress concentrations are not sufficient to negatively impact the bat, thereby ensuring solid performance under normal circumstances. Additionally, the increased-thickness sections 250 allow the performance of the barrel 215 to stay under various performance thresholds set by various agencies at the sweet spot of the barrel 215. The short transition sections at shoulders 310 also help to reduce weight, resulting in better performance.
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.
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.”
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.

Claims

What is claimed is:

1. A ball bat comprising:

a handle having a knob end and an attachment end;

a tapered portion extending from the attachment end of the handle;

a barrel portion extending from the tapered portion to an end-cap end, wherein said barrel portion includes:

an inner surface;

an outer surface;

a uniform thickness between the inner and outer surfaces; and

a point of maximum performance; and

at least one increased-thickness section molded and cured integrally with the barrel portion such that composite material forming the barrel portion and at least one increased-thickness section is uniform,

wherein said at least one increased-thickness section is positioned at or near the point of maximum performance, and

wherein each increased-thickness section has a thickness greater than the uniform thickness.

2. The ball bat of claim 1 wherein a said increased-thickness section is positioned at the point of maximum performance.

3. The ball bat of claim 1 wherein a said increased-thickness section is positioned between proximate the point of maximum performance.

4. The ball bat of claim 1 wherein a said increased-thickness section is positioned between about three to eight inches from the end-cap end.

5. The ball bat of claim 1 wherein the thickness of a said increased-thickness section is between about 0.300 inches and 0.400 inches.

6. The ball bat of claim 1, wherein the thickness of a said increased-thickness section is about 0.350 inches.

7. The ball bat of claim 1, wherein the uniform thickness is between about 0.110 inches and 0.140 inches.

8. The ball bat of claim 1, wherein the barrel portion is formed from composite materials having constituent matrix components with different angles as compared to said at least one increased-thickness section.

9. The ball bat of claim 8, wherein the barrel portion uses 45-degree reinforcement components and said at least one increased-thickness section uses 55-degree reinforcement components.

10. A composite ball bat comprising:

a handle having a knob end and an attachment end;

a tapered portion extending from the attachment end of the handle;

an inner surface;

an outer surface;

a uniform thickness between the inner and outer surfaces; and

a point of maximum performance; and

at least one increased-thickness section positioned along the inner surface of the barrel positioned at or near the point of maximum performance;

wherein each increased-thickness section has a thickness greater than the uniform thickness; and

wherein a transition between the uniform-thickness of the barrel and the increased-thickness section occurs over a distance of approximately 0.140 inches or less.

11. The ball bat of claim 10 wherein the transition between the uniform-thickness of the barrel and the increased-thickness section occurs over a distance of between approximately 0.080 inches and 0.140 inches.

12. The ball bat of claim 10 wherein a said increased-thickness section is positioned at the point of maximum performance.

13. The ball bat of claim 10 wherein a said increased-thickness section is positioned proximate the point of maximum performance.

14. The ball bat of claim 10 wherein a said increased-thickness section is positioned between about three to eight inches from the end-cap end.

15. The ball bat of claim 10 wherein the thickness of a said increased-thickness section is between about 0.300 inches and 0.400 inches.

16. The ball bat of claim 10, wherein the thickness of a said increased-thickness section is about 0.350 inches.

17. The ball bat of claim 10, wherein the uniform thickness is between about 0.110 inches and 0.140 inches.

18. The ball bat of claim 10, wherein the barrel portion is formed from composite materials having constituent matrix components with different angles as compared to said at least one increased-thickness section.

19. The ball bat of claim 18, wherein the barrel portion uses 45-degree reinforcement components and said at least one increased-thickness section uses 55-degree reinforcement components.

20. A method of making a composite ball bat comprising the steps of:

forming an uncured composite ball bat to include:

a handle having a knob end and an attachment end;

a tapered portion extending from the attachment end of the handle;

an inner surface;

an outer surface;

a uniform thickness between the inner and outer surfaces; and

a point of maximum performance;

positioning the uncured composite ball bat within an external mold section;

positioning an internal mold section within the inner surface of the barrel portion, wherein the internal mold section includes an inflatable bladder;

inflating the inflatable bladder to conform to the inner surface and the at least one increased-thickness section positioned therealong;

curing the uncured composite ball bat to form the composite ball bat;

deflating the inflatable bladder to remove the internal mold section from composite ball bat.