Note: Descriptions are shown in the official language in which they were submitted.
Attorney Docket No. 113507-8134.US00
BALL BATS WITH REDUCED DURABILITY REGIONS FOR
DETERRING ALTERATION
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part of U.S. Patent
Application No.
15/654,513, filed July 19, 2017, which is incorporated herein in its entirety
by reference.
BACKGROUND
[0002] Baseball and softball governing bodies have imposed various bat
performance
limits over the years with the goal of regulating batted ball speeds. Each
association
generally independently develops various standards and methods to achieve a
desired
level of play.
[0003] During repeated use of bats made from composite materials, the
matrix or
resin of the composite material tends to crack and the fibers tend to stretch
or break.
Sometimes the composite material develops interlaminar failures, which involve
plies or
layers of composite materials in a composite bat separating or delaminating
from each
other along a failure plane between the layers. This break-in tends to reduce
stiffness and
increase the elasticity or trampoline effect of a bat against a ball, which
tends to
temporarily increase bat performance.
[0004] As a bat breaks in, and before it fully fails (for example, before
the bat wall
experiences a through-thickness failure), it may exceed performance
limitations specified
by a governing body, such as limitations related to batted ball speed. Some
such
limitations are specifically aimed at regulating the performance of a bat that
has been
broken in from normal use (such as BBCOR, or "Bat-Ball Coefficient of
Restitution").
-1-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0005]
Some unscrupulous players choose to intentionally break in composite bats to
increase performance. Intentional break-in processes may be referred to as
accelerated
break-in (ABI) and may include techniques such as "rolling" a bat or otherwise
compressing it, or generating hard hits to the bat with an object other than a
ball. Such
processes tend to be more abusive than break-in during normal use. A rolled or
otherwise
intentionally broken-in bat may temporarily exceed limitations established by
a governing
body. Accordingly, unscrupulous users may be able to perform an ABI procedure
to
increase performance without causing catastrophic failure of the bat that
would render it
useless.
SUMMARY
[0006]
Representative embodiments of the present technology include a ball bat with
a handle, a barrel attached to or continuous with the handle along a
longitudinal axis of the
bat, and a reduced-durability region positioned in the barrel. The reduced-
durability region
may include two adjacent stacks of composite laminate plies, wherein the
stacks are
spaced apart from each other along the longitudinal axis to form a first gap
therebetween.
A separation ply may be positioned in the first gap between the stacks. In
some
embodiments, the separation ply may include a composite fiber mat.
In some
embodiments, the separation ply may include a release ply. In some
embodiments, the
separation ply includes a non-woven fiber mat material. At least one cap ply
element may
be positioned around an end of one of the stacks. In some embodiments, an axis
of the
first gap is oriented at an oblique angle relative to the longitudinal axis of
the bat. In some
embodiments, at least one of the stacks includes one or more fibrous bundles,
the one or
-2-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
more fibrous bundles being oriented transverse to the at least one of the
stacks and
extending at least partially circumferentially about the barrel.
[0007] The barrel may further include an outwardly facing skin facing
away from the
barrel and an inwardly facing skin facing an interior hollow region of the
barrel. At least
one of the outwardly facing skin or the inwardly facing skin may include a
discontinuity
forming a second gap in the at least one of the outwardly facing skin or the
inwardly facing
skin along the longitudinal axis, the first gap and the second gap being
connected to each
other. A cover layer may be positioned over the second gap. The cover layer
may include
carbon fiber composite.
[0008] In some embodiments, a ring element may be positioned in a gap
between the
stacks. The ring element may include a rigid or semi-rigid material. A first
bond between
the ring element and adjacent composite matrix material may be weaker than a
second
bond between the composite laminate plies in each of the stacks. In some
embodiments,
the ring element may have a rectangular or otherwise elongated cross-section
that is
oriented perpendicular to the longitudinal axis of the ball bat. In some
embodiments, the
ring element may have a cross-section that is oriented at an oblique angle
relative to the
longitudinal axis. In some embodiments, the ring element may have a triangular
cross-
section, a square cross-section, or other cross-sectional shapes.
[0009] The reduced-durability region may include one or more composite
laminate
plies positioned between the ring element and at least one of an outwardly
facing skin or
an inwardly facing skin of the ball bat. In some embodiments, the reduced-
durability
region may further include a second ring element, which may be spaced apart
from the
first ring element, with a composite laminate ply therebetween, or the second
ring element
-3-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
may be attached to the first ring element. In some embodiments, the second
ring element
may be attached to the first ring element with a bond or other connection that
is configured
to fail under a stress that is less than a stress that would cause failure of
a bond between
composite laminate plies in the stacks.
[0010] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] In the drawings, wherein the same reference number indicates the
same
element throughout the views:
[0012] Figure 1 illustrates a ball bat according to an embodiment of the
present
technology.
[0013] Figure 2 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to an embodiment of the present
technology.
[0014] Figure 3 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to another embodiment of the
present
technology.
[0015] Figure 4 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to another embodiment of the
present
technology.
-4-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0016] Figure 5 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to another embodiment of the
present
technology.
[0017] Figure 6 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to another embodiment of the
present
technology.
[0018] Figure 7 illustrates a partial cross-sectional view of a portion
of a barrel wall
having a reduced-durability region according to another embodiment of the
present
technology.
[0019] Figures 8, 10-16, and 18 illustrate partial cross-sectional views
of portions of
barrel walls having reduced-durability regions according to other embodiments
of the
present technology.
[0020] Figures 9 and 19 illustrate isometric views of appliances in the
form of ring
elements according to embodiments of the present technology.
[0021] Figure 17 illustrates a cross-sectional view of an appliance in
the form of a ring
element according to another embodiment of the present technology.
DETAILED DESCRIPTION
[0022] The present technology is directed to ball bats with reduced-
durability regions
for deterring alteration, and associated systems and methods. Various
embodiments of
the technology will now be described. The following description provides
specific details
for a thorough understanding and enabling description of these embodiments.
One skilled
-5-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
in the art will understand, however, that the invention may be practiced
without many of
these details. Additionally, some well-known structures or functions, such as
structures or
functions common to ball bats and composite materials, may not be shown or
described in
detail so as to avoid unnecessarily obscuring the relevant description of the
various
embodiments.
Accordingly, embodiments of the present technology may include
additional elements or exclude some of the elements described below with
reference to
Figures 1-19, which illustrate examples of the technology.
[0023]
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.
[0024]
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.
[0025]
Specific details of several embodiments of the present technology are
described herein with reference to baseball or softball. The technology may
also be used
in other sporting good implements or in other sports or industries in which it
may be
-6-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
desirable to discourage tampering, damage, or overuse in composites or other
structures.
Conventional aspects of ball bats and composite materials may be described in
reduced
detail herein for efficiency and to avoid obscuring the present disclosure of
the technology.
In various embodiments, a number of different composite materials suitable for
use in ball
bats may be used, including, for example, composites formed from carbon fiber,
fiberglass,
aramid fibers, or other composite materials or combinations of matrices,
resins, fibers,
laminates, and meshes forming composite materials.
[0026] Turning now to the drawings, Figure 1 illustrates a ball bat 100
having a barrel
portion 110 and a handle portion 120. There may be a transitional or taper
portion 130 in
which a larger diameter of the barrel portion 110 transitions to a narrower
diameter of the
handle portion 120. The handle portion 120 may include an end knob 140 and the
barrel
portion 110 may optionally be closed with an end cap 150. The barrel portion
110 may
include a non-tapered or straight section 160 extending between the end cap
150 and an
end location 170.
[0027] The bat 100 may have any suitable dimensions. For example, the bat
100
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 100, and may vary greatly among users.
[0028] The barrel portion 110 may be constructed with one or more
composite
materials. Some examples of suitable composite materials include plies
reinforced with
-7-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
fibers of carbon, glass, graphite, boron, aramid (such as Kevlar0), ceramic,
or silica (such
as Astroquartz0). The handle portion 120 may be constructed from the same
materials
as, or different materials than, the barrel portion 110. In a two-piece ball
bat, for example,
the handle portion 120 may be constructed from a composite material (the same
or a
different material than that used to construct the barrel portion 110), a
metal material, or
any other material suitable for use in a striking implement such as the bat
100.
[0029] Figures 2-8, 10-16, and 18 illustrate partial cross-sectional
views of a portion
of the straight section 160 of the bat barrel 110 according to embodiments of
the present
technology. Each of Figures 2-8, 10-16, and 18 illustrates a two-dimensional
projection of
a cross-section of a wall of the barrel between an interior portion of the bat
and the exterior
of the bat. For example, Figures 2-8, 10-16, and 18 may illustrate a part of
the bat 100 in
section A indicated in Figure 1, or they may illustrate other sections.
[0030] Figure 2 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 200 in the straight section 160 of the bat 100 according to an
embodiment of
the present technology. The wall 200 defines an outer structure of the bat
100, which may
be hollow in some embodiments. The wall 200 may have an inwardly facing skin
210
positioned to face toward an interior area of the bat 100, and an outwardly
facing skin 220
positioned to face outwardly from the bat 100. In some embodiments, the bat
100 may
include interior structural elements within the composite wall 200 or
elsewhere in the bat
100. The composite barrel wall 200 may be formed from a variety of materials
such as the
composite materials described herein. For example, the inwardly facing skin
210 or the
outwardly facing skin 220 may be formed with a composite material including
carbon fibers
-8-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
oriented at approximately 60 degrees relative to the longitudinal axis of the
bat 100. Any
other suitable fibrous materials and fiber angles may be used.
[0031] A reduced-durability region 230 may include two or more stacks 240
of plies
250 of laminate materials positioned on each side of a discontinuity or gap
region 260
inside the wall 200. Although the gap region 260 is described as being located
between
two or more stacks 240, the gap region 260 may also be considered a
discontinuity in what
would otherwise be a continuous single stack 240 of plies 250. Although five
plies 250 are
illustrated in each stack 240, any suitable number of plies 250 may form each
stack 240,
and the stacks 240 may have different quantities of plies 250 from each other.
In various
embodiments, the plies 250 forming the stacks 240 may be formed from any
material or
materials suitable for use in ball bats, striking implements, or other
equipment, including,
for example, carbon fiber in a matrix, glass fiber in a matrix, aramid fibers
in a matrix, or
other composite materials or combinations of matrices, resins, fibers, or
meshes forming
composite laminate layers, including other composite materials described
herein. The
plies 250, the outwardly facing skin 220, and the inwardly facing skin 210 may
be formed
from pre-impregnated material cured in a mold. In some embodiments, resin
transfer
molding processes may be used to form the various layers of embodiments of the
technology.
[0032] In a conventional bat that does not include a gap region 260 (in
other words, in
a bat with a continuous stack of plies), stresses in the bat wall would
generally be
distributed along the length of the plies (generally along a longitudinal axis
of the bat). In
such a conventional bat, forces from impact or other stresses would generally
cause the
plies to delaminate from each other. The gap region 260 focuses or directs the
stress
-9-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
concentration between the stacks 240, thereby creating a new failure plane in
addition to
existing failure modes, such as delamination. For example, when a bat is
rolled or
otherwise tampered with, or when a bat has been overly broken in or overused,
the wall
200 may break through and along the gap region 260, such as along the Z-axis
(labeled
"z") of the bat wall 200 or otherwise along a path between the inwardly facing
skin 210 and
the outwardly facing skin 220. Such a break may cause the wall 200 to fail
(destroying the
bat) before significant delamination occurs that would otherwise improve
performance
(including performance that may violate league or organization rules or is
otherwise
undesirable). In other words, the gap region 260 weakens the strength of the
wall 200
along the Z-axis such that it is weaker than the axial (along the longitudinal
axis of the bat)
interlaminar strength.
[0033]
In some bats with gaps or discontinuities between stacks of plies, the gap may
be too strong or too narrow to reliably provide such a break after overuse or
abuse. In
other words, in some bats with gap regions that are too strong, delamination
may occur to
a significant (or undesirable) degree before a break in the gap region causes
total failure of
the wall. For example, during the molding process for a composite bat with a
gap (such as
the gap region 260), plies (such as the plies 250) may move, narrowing or even
closing the
gap, which may delay or disrupt the failure along the gap. According to
embodiments of
the present technology, to prevent such movement and to lower the energy
needed to
trigger the thickness failure along the gap region 260 to a level at which the
thickness
failure occurs before the plies 250 in the stacks 240 delaminate, an appliance
such as a
separation ply 270 may be positioned in the gap region 260.
-10-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0034] The appliance, such as the separation ply 270, also reduces or
prevents
interweaving, nesting, or bonding of the stacks 240 across the gap region 260,
thereby
resisting or preventing an undesirable increase in strength at the gap region
260 relative to
a gap without such a separation ply 270. For example, if the separation ply
270 allows
some bonding between the stacks 240, the gap region 260 may be stronger. If
the
separation ply 270 is a barrier, it may allow only minimal bonding or no
bonding at all
across the gap region 260, resulting in a weaker gap region 260. By managing
the
strength of the wall 200 at the gap region 260, the level of energy at which
failure of the
wall 200 occurs at the gap region 260 can be tailored to be lower than the
energy required
to delaminate the stacks 240 in a particular bat configuration.
[0035] The separation ply 270 may be formed from any suitable material,
depending
on the level of bonding desired between the stacks 240. For example, in a
heavier bat or
in a bat with a relatively high moment of inertia (for example, near or above
6000 ounce-
square inch), in which a strong gap region 260 is desired, a strong material
may be used,
such as one or more carbon fiber or glass fiber composite mats or other fiber
composite
mats. In some embodiments, the separation ply 270 may be rigid or semi-rigid,
while in
other embodiments it may be flexible. In a lighter bat or in a bat with a
relatively low
moment of inertia (for example, near or below 6000 ounce-square inch), in
which a gap
region 260 may not need to be as strong, a release ply material, such as
polytetrafluoroethylene (PTFE, commercially available as TEFLON), nylon sheet,
or other
release plies may be used. In some embodiments, the release ply material may
be
perforated or porous, which may increase the strength of the gap region 260 by
allowing
limited bonding between the stacks 240.
-11-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0036] In a particular representative embodiment, the separation ply 270
may be
formed from a non-woven mat material having a fiber aerial weight of
approximately 30
grams per square meter. Such a material may include a variety of types of
fibers and
treatments and may function as an inexpensive and reliable material for
providing a
desired strength in the gap region 260.
[0037] The reduced-durability region 230 (centered around the middle of
the gap
region 260) may be located along the straight section 160 of the bat barrel
110 (see Figure
1). For example, with reference to Figure 1, in some embodiments, the reduced-
durability
region 230 may be located within section A, or it may be located anywhere
between
approximately one inch from the distal end of the bat 100 having end cap 150
and
approximately one inch from the end location 170 of the straight section 160.
In other
embodiments, the reduced-durability region 230 may be located in other
portions of the bat
100. In general, the reduced-durability region 230 may be positioned anywhere
a bat may
be rolled or tampered with by a user, or anywhere a regulatory body wishes to
test the bat
100. In some embodiments, the reduced-durability region 230 may be positioned
at or
near the center of percussion of the bat 100, as measured by the ASTM F2398-11
Standard. In some embodiments, the reduced-durability region 230 may be
positioned
somewhere between the center of percussion and the end location 170 of the
straight
section 160.
[0038] Figure 3 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 300 in the straight section 160 of the bat 100 having a reduced-
durability region
330 according to another embodiment of the present technology. The wall 300
illustrated
in Figure 3 may be generally similar to the wall 200 illustrated and described
above with
-12-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
regard to Figure 2, but it may further include one or more cap ply elements
310, which are
described in additional detail below. For example, the barrel wall 300 may
include an
inwardly facing skin 210, an outwardly facing skin 220, stacks 240 of plies
250 on either
side of a gap region 260, and a separation ply 270 to reduce or prevent
bonding across the
gap region 260.
[0039] When a crack forms in the gap region 260, the cap ply elements 310
prevent
(or at least resist) proliferation of the crack to the stacks 240 of plies
250. In other words,
the cap ply elements 310 prevent or resist delamination of the stacks 240 of
plies 250 by
preventing or resisting spreading of the crack along the axial length of the
bat (i.e., along
the longitudinal or x-axis of the bat, marked with "x" in Figure 3). Thus,
when a crack
forms it will be generally directed along the z-axis through the gap region
260 or otherwise
along the gap region 260 between the inwardly facing skin 210 and the
outwardly facing
skin 220, as described above.
[0040] The cap ply elements 310 may be formed from a foam material, a
plastic
material, or another material suitable for being folded, molded, or otherwise
shaped around
an edge of each of the stacks 240. In some embodiments, the cap ply elements
310 may
be formed from similar materials as the separation ply 260. In some
embodiments, the
cap ply elements 310 may be rigid. In other embodiments, the cap ply elements
310 may
be flexible (for example, they may be formed with an elastomer material to
make the cap
ply elements 310 resilient). Because Figure 3 illustrates a cross-section, it
is understood
that each cap ply element 310 may be in the form of a ring positioned along
the
circumference of an assembled bat.
-13-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0041] Figure 4 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 400 in the straight section 160 of the bat 100 having a reduced-
durability region
430 according to another embodiment of the present technology. The wall 400
illustrated
in Figure 4 may be generally similar to the wall 300 illustrated and described
above with
regard to Figure 3. In addition, the stacks 240 of plies 250 may also include
one or more
circumferential fibers or fibrous bundles 410 positioned at the end of the
stacks 240
between the stacks 240 and the cap ply elements 310. The fibrous bundles 410
may be
oriented to be generally transverse (such as perpendicular) to the plies 250,
for example,
they may be positioned circumferentially through the interior of the barrel
wall 400 around
at least a portion of the bat. The fibrous bundles 410 increase local
stiffness in the vicinity
of the gap region 260 to help guide the failure of the wall 400 through the
gap region 260.
Although the fibrous bundles 410 are illustrated as being adjacent to the cap
ply elements
310 in Figure 4, in some embodiments, they may be positioned in other
locations.
[0042] For example, Figure 5 illustrates a partial cross-sectional view
of a portion of a
composite barrel wall 500 in the straight section 160 of the bat 100 having a
reduced-
durability region 530 according to another embodiment of the present
technology. The
wall 500 illustrated in Figure 5 may be generally similar to the wall 300
illustrated and
described above with regard to Figure 3. In addition, the stacks 240 of plies
250 may also
include one or more circumferential fibers 510 positioned between plies 250 in
the stacks
240. For example, there may be a plurality of circumferential fibers or
fibrous bundles 510
sandwiched between two or more plies 250. The fibrous bundles 510 may be
oriented
transverse (such as perpendicular) to the plies 250, for example, they may be
positioned
circumferentially through the interior of the wall 500 around at least a
portion of the bat.
-14-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
The fibrous bundles 510 increase local stiffness of the barrel at a distance
from the gap
region 260 to further customize the strength of the gap region 260 or to
further concentrate
stresses in the gap region 260. In some embodiments, one or more of the
fibrous bundles
510 may be positioned at a distance of approximately 1 to 2, inches from the
reduced-
durability region 530.
[0043] Figure 6 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 600 in the straight section 160 of the bat 100 having a reduced-
durability region
630 according to another embodiment of the present technology. The wall 600
illustrated
in Figure 6 may be generally similar to the wall 300 illustrated and described
above with
regard to Figure 3, but the gap region 260 extends through at least one of the
inwardly
facing skin 610 and the outwardly facing skin 620. For example, one or both of
the
inwardly facing skin 610 or the outwardly facing skin 620 may have a gap or
discontinuity
640 that extends the gap region 260 through one or both of the inwardly facing
skin 610 or
the outwardly facing skin 620. The discontinuity 640 in the inwardly facing
skin 610 or the
outwardly facing skin 620 may be aligned with the gap region 260. A cover
layer 650 may
be positioned to cover the gap region 260 and the discontinuity 640.
[0044] Although two cover layers 650 are illustrated, in some embodiments
with only
one discontinuity 640, only one cover layer 650 may be used. The cover layers
650 may
be formed with intermediate modulus carbon fiber composite (which may have a
Young's
Modulus or elastic modulus between approximately 42 million pounds per square
inch and
55 million pounds per square inch) or another composite or non-composite
material
suitable for allowing through-failure of the bat wall 600 before significant
delamination
occurs in the stacks 240 of plies 250. Intermediate modulus carbon fiber
materials may be
-15-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
beneficial because they generally provide more stiffness per unit weight than
standard
carbon fiber materials (which may have elastic modulus values around 33
million pounds
per square inch). Intermediate modulus materials provide more stiffness than
standard
fiber materials while generally being less costly and less brittle than higher
modulus fiber
materials (which have elastic modulus values greater than 55 million pounds
per square
inch). The embodiment of the wall 600 and the reduced-durability region 630
illustrated
and described with regard to Figure 6 allows for further customization of the
strength of the
reduced-durability region 630 and the gap region 260.
[0045]
Figure 7 illustrates a partial cross-sectional view of a portion of a
composite
barrel wall 700 in the straight section 160 of the bat 100 having a reduced-
durability region
730 in accordance with another embodiment of the present technology. The wall
700
illustrated in Figure 7 may be generally similar to the wall 300 illustrated
and described
above with regard to Figure 3, but the gap region 260 is oriented at an
oblique angle. For
example, an axis 710 of the gap region 260 (parallel to the transverse
portions 720 of the
cap ply elements 750 abutting the stacks 740) may be oriented at an angle 760
relative to
the longitudinal or X-axis (labeled "x") of the bat. The angle 760 may have a
value of
between 1 and 89 degrees, for example, it may be between 30 and 65 degrees, or
60
degrees in a particular embodiment. The stacks 740, having plies 250, may be
staggered
or angled to correspond to the angle 760 of the gap region 260. The separation
ply 270
may also be angled to correspond to the angle 760 of the gap region 260.
Likewise, the
cap ply elements 750, which may be similar to the cap ply elements 310
described above,
may have transverse portions 720 that are also oriented along the angle 760.
-16-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0046] In some embodiments, when the angle 760 is relatively small, the
wall 700 and
the reduced-durability region 730 increase in strength. For example, the wall
700 and the
reduced-durability region 730 may withstand more forces before experiencing a
through-
failure in the gap region 260.
[0047] As described above, the separation ply 270 may cause failure to
propagate
through the wall of a bat (e.g., through the stacks 240) along the Z-axis
within or along the
gap regions 260 faster than failure occurring in bats without reduced
durability regions
(such as those without gap regions 260). In other embodiments of the present
technology,
other appliances may provide similar effects. Figures 8-19 illustrate
embodiments with
other appliances to control failure along the Z-axis through the bat wall. In
some
embodiments, rigid or semi-rigid appliances, such as those described below,
may reduce
the risk that interlaminar failures (which can cause undesirable increases in
performance)
occur before a bat fails through its wall along the Z-axis. Such rigid or semi-
rigid
appliances may improve control and consistency of the strength properties of a
bat wall.
[0048] Figure 8 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 800 in the straight section 160 of the bat 100 having a reduced-
durability region
830 according to another embodiment of the present technology. The wall 800
illustrated
in Figure 8 may be generally similar to the wall 200 illustrated and described
above with
regard to Figure 2, but instead of using a separation ply 270 to guide failure
through the
bat wall, the appliance positioned in the gap region 260 may be a ring element
810 (see
Figure 9). The ring element 810 functions similarly to the separation ply 270
in that it
reduces or prevents bonding across the gap region 260 and guides failure
through the bat
wall along the Z-axis. The ring element 810, however, facilitates a more
predictable
-17-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
fracture location and a more predictable level of strain at which failure may
occur. The ring
element 810 may be formed as a single piece or as multiple pieces connected
together,
with or without discontinuities along its circumference. In some embodiments,
the ring
element 810 may have a rectangular or otherwise elongated cross-section 815
that is
oriented along the Z-axis, perpendicular to the longitudinal axis of the bat
(the X-axis),
such that the ring element 810 traverses across the stacks 240 in a direction
perpendicular
to the plies 250. In other embodiments, the ring element 810 need not be
oriented
perpendicular to the longitudinal axis of the bat, and it may have other
orientations (for
example, see below with regard to Figure 10). In some embodiments, the cross-
section
815 may be square-shaped, or it may have other suitable shapes.
[0049] When a crack forms in the gap region 260, the ring element 810
prevents (or
at least resists) proliferation of the crack to the stacks 240 of plies 250.
In other words, the
ring element 810 prevents or resists delamination of the stacks 240 of plies
250 by
preventing or resisting spreading of the crack along the axial length of the
bat (i.e., along
the longitudinal or X-axis of the bat, marked with "x" in Figure 8). Thus,
when a crack
forms it will be generally directed along the Z-axis through the gap region
260 or otherwise
along the gap region 260 between the inwardly facing skin 210 and the
outwardly facing
skin 220.
[0050] Appliances may have a variety of shapes. The size, shape, and
dimensions of
the ring element 810 and other appliances described below may be adjusted to
meet the
desired overall strength of the bat in normal use and during ABI processes,
the bond
strength between the composite resin or matrix and the appliance (such as the
ring
element 810), and the strength of the appliance itself (such as the ring
element 810).
-18-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0051]
For example, rigid or semi-rigid appliances may be formed with a high-surface-
energy material such as acetal polymer (for example, Delrin 0),
polytetrafluoroethylene
(PTFE, for example, Teflon 0), polyoxymethylene (POM), polyamides (Nylon),
polyethylene terephthalate (PET), or other suitable plastic or polymer
materials. Such
high-surface-energy materials resist or even prevent bonding between the
composite
matrix and the appliance. A weak or nonexistent bond between the composite
matrix and
the appliance facilitates rapid and predictable failure of the bond. In
embodiments of the
present technology that implement a high-surface-energy material or another
material that
provides a weak or nonexistent bond between the composite matrix and the
appliance, the
inwardly facing skin 210 and the outwardly facing skin 220 may be constructed
to be
sufficiently strong to handle the stress of normal use, but sufficiently weak
to fail during ABI
processes. In some embodiments, one or more plies 250 may not include a
discontinuity
or gap and may further strengthen the reduced-durability region (as described
below, for
example, with regard to Figure 11).
For example, an appliance may traverse
approximately 25% of the wall thickness t, or other fractions thereof.
[0052]
In some embodiments, appliances may be formed with materials having
moderate to strong bond strength with the surrounding composite matrix
material in the bat
wall. Such materials may provide further control of how much strain is
required to cause
the bat wall to fracture. Materials that may provide moderate to strong bond
strength with
the composite matrix material (which may be epoxy or polyurethane resin, for
example)
include acrylonitrile butadiene styrene (ABS), polyvinyl chloride (PVC),
polycarbonate
(PC), polyurethane (PU). Other materials may provide moderate to strong bond
strength
with the composite matrix material.
-19-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0053] In some embodiments, appliances described herein may be formed
from a
breakable material such that the appliances themselves fracture before
delamination
occurs. In some embodiments, some appliances may be scored or etched to force
a
failure or breaking point. In some embodiments, appliances may be made by a
method
that provides inherent flaws, such as a 3D printing process. In a particular
embodiment,
ABS material provides a balance between the strength of the bond with the
composite
matrix material and the strength of the appliance itself. In some embodiments,
an
appliance made with ABS material may be weaker than the interlaminar bond
between the
composite plies 250.
[0054] In yet other embodiments, appliances may be formed with metal,
such as
aluminum, steel, or titanium, or other metals, foam materials, or wood, or any
other
suitable rigid or semi-rigid material. In general, a designer may select the
appropriate
material for the appliance based on the strength of a bond between the
material and the
composite matrix, or based on the strength of the material itself.
[0055] In some embodiments, appliances may be formed with composite
material
(such as composite laminate material, bulk molding compound, or sheet molding
compound). In some embodiments, a composite appliance may be pre-formed with
composite material and pre-cured, then installed in a ball bat composite layup
during
manufacturing. In some embodiments in which appliances are formed with
composite
materials, the strength or stiffness of the appliances may be selected or
designed to match
or exceed the strength or stiffness of the composite material located next to
the appliance
in the gap. In some embodiments, because the appliances may be pre-cured, they
may
have a reduced bond strength with neighboring composite material in the bat
wall relative
-20-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
to composites that are cured simultaneously. Accordingly, the bond strength of
a pre-
cured composite appliance may be lower than the interlaminar strength between
composite laminate plies 250. For example, the bond strength of a pre-cured
composite
appliance may be only approximately 75 to 80 percent of the bond strength of
plies 250,
which facilitates failure along the sides or within the appliance at lower
stress levels than
those that may cause interlaminar failure.
[0056] Figure 10 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1000 in the straight section 160 of the bat 100 having a reduced-
durability
region 1030 according to another embodiment of the present technology. The
wall 1000
illustrated in Figure 10 may be generally similar to the wall 800 illustrated
and described
above with regard to Figure 8, but the appliance may be in the form of a
beveled ring
element 1010. The beveled ring element 1010 may resemble the ring element 810,
but it
may have a cross-section that traverses an angled gap region 260, or is
otherwise oriented
at an oblique angle relative to the stacks 240 of plies 250. For example, a
cross-section of
the beveled ring element 1010 may have an axis 1040 that is oriented at an
angle 1020
(such as an oblique angle) relative to the longitudinal or X-axis of the bat,
or to the plies
250. The angle 1020 may have a value between 30 degrees and 90 degrees (for
example, 45 degrees). The stacks 240, having plies 250, may be staggered or
angled to
correspond to the angle 1020 of the beveled ring element 1010.
[0057] The beveled ring element 1010 functions generally similarly to the
flat ring
element 810 described above with regard to Figure 8, but the angle 1020
facilitates
additional modification of the fracture properties of the wall 1000. In some
embodiments,
when the angle 1020 is relatively small, the wall 1000 and the reduced-
durability region
-21-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
1030 increase in strength. For example, the wall 1000 and the reduced-
durability region
1030 may withstand more forces before experiencing a through-failure in the
gap region
260 than would a flat ring element 810 (Figure 8), depending on the materials
forming the
appliance and the bond strength between the appliance and the composite matrix
in the
wall. The beveled ring element 1010 may be formed as a single piece or as
multiple
pieces connected together, with or without discontinuities along its
circumference.
[0058]
Figure 11 illustrates a partial cross-sectional view of a portion of a
composite
barrel wall 1100 in the straight section 160 of the bat 100 having a reduced-
durability
region 1130 according to another embodiment of the present technology. The
reduced-
durability region 1130 in Figure 11 is generally similar to the reduced-
durability region 1030
described and illustrated above with regard to Figure 10, except that the
appliance may be
in the form of a beveled ring element 1110 that extends through only a portion
of the
stacks 240 of plies 250. For example, the gap region 260 between the stacks
240 may not
extend through all the plies 250, such that one or more plies 250 are
continuous in the
reduced-durability region 1130. In other words, the beveled ring element 1110
may
occupy between 25 percent and 50 percent of the overall thickness t of the
barrel wall
1100. The plies 250 that are continuous (not interrupted by a gap or an
appliance) may be
referred to as through-plies. Any suitable number of through-plies may be
positioned in
the wall 1100, toward the outwardly facing skin 220 (such as one or more
through-plies
between the ring element 1110 and the outwardly facing skin 220) or toward the
inwardly
facing skin 210 (such as one or more through-plies between the ring element
1110 and the
inwardly facing skin 210).
-22-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0059] Figure 12 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1200 in the straight section 160 of the bat 100 having a reduced-
durability
region 1230 according to another embodiment of the present technology. The
reduced-
durability region 1230 in Figure 12 is generally similar to the other reduced-
durability
regions described herein, except that the appliance may be in the form of a
ring element
1210 with a triangular cross-section 1215. The triangular cross-section 1215
may have
any suitable dimensions. For example, it may be sized to fully or almost fully
extend
between the inwardly facing skin 210 and the outwardly facing skin 220. The
ring element
1210 may be sized to allow plies 250 (such as through-plies) to pass between
the ring
element 1210 and the inwardly facing skin 210 or the outwardly facing skin
220. The
triangular cross-section 1215 may have equilateral proportions, isosceles
proportions,
scalene proportions, or other proportions. The triangular cross-section 1215
may include
any suitable angles, such as a right angle. Although the triangular cross-
section 1215 is
illustrated as having one side that is parallel with the X-axis of the bat, in
various
embodiments, the triangular cross-section 1215 may have other orientations.
[0060] Figure 13 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1300 in the straight section 160 of the bat 100 having a reduced-
durability
region 1330 according to another embodiment of the present technology. The
reduced-
durability region 1330 in Figure 13 is generally similar to the other reduced-
durability
regions described herein, including the reduced-durability region 1230
illustrated in Figure
12 and described above. In some embodiments, the appliance may be in the form
of a
ring element 1310 that is similar to the ring element 1210 illustrated and
described above
with regard to Figure 12, but with a triangular cross-section 1315 that is
smaller than the
-23-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
cross-section 1215 illustrated in Figure 12. For example, the triangular cross-
section 1315
may span approximately 25% of the overall wall thickness t of the barrel wall
1300. In
some embodiments, the triangular cross-section 1315 may be positioned adjacent
to one
of the skins 210, 220, or there may be one or more through-plies 250 between
the inwardly
facing skin 210 and the triangular cross-section 1315 or between the outwardly
facing skin
220 and the triangular cross-section 1315. In some embodiments, the triangular
cross-
section 1315 may be positioned in a gap region 260 that includes gaps between
any
suitable number of composite laminate plies 250 (for example, as shown in the
illustration
in Figure 13, two plies 250 may have gaps within which the ring element 1310
is situated).
[0061]
Figure 14 illustrates a partial cross-sectional view of a portion of a
composite
barrel wall 1400 in the straight section 160 of the bat 100 having a reduced-
durability
region 1430 according to another embodiment of the present technology. The
reduced-
durability region 1430 in Figure 14 is generally similar to the other reduced-
durability
regions described herein, including the reduced-durability region 1330
illustrated in Figure
13 and described above. In some embodiments, there may be two appliances
positioned
in the gap region 260 (the gap region 260 may have multiple longitudinal gaps
between
plies 250). The appliances may be similar to other appliances described
herein. In some
embodiments, the appliances may be in the form of ring elements 1410 that may
be
generally similar to the ring elements 1310 described above with regard to
Figure 13. For
example, the ring elements 1410 may have triangular cross-sections 1415 and
they may
be positioned anywhere in the gap region 260, within a discontinuity or break
between
composite laminate plies 250. In some embodiments, one or more plies (such as
the
through-ply 1417) may be positioned between the ring elements 1410, or a space
between
-24-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
the ring elements 1410 may be filled with composite matrix material, or the
space between
the ring elements 1410 may be a void. The quantity, shape, and arrangement of
ring
elements 1410 functioning as appliances may be selected to tailor the force
required to
break through the bat wall 1400 in the reduced-durability region 1430 before
the composite
laminate plies delaminate.
[0062] In embodiments that include a single appliance, such as the
embodiments
described above and illustrated in Figures 8 and 10-13, or a plurality of
appliances (spaced
apart or adjacent to each other), such as the embodiment described above and
illustrated
in Figure 14, a bond strength between an appliance and the composite matrix or
resin may
be designed to be close to or greater than the interlaminar strength of nearby
plies 250. In
such embodiments, there may be a risk that interlaminar failure occurs before
the bond
between the appliance and the matrix or resin is broken, leading to increased
bat
performance. To reduce that risk, in some embodiments, a designer may provide
through-
plies in the reduced-durability region, and the designer may provide a weaker
bond
between the through-plies and other plies or appliances.
[0063] Figure 15 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1500 in the straight section 160 of the bat 100 having a reduced-
durability
region 1530 according to another embodiment of the present technology. The
reduced-
durability region 1530 in Figure 15 is generally similar to the other reduced-
durability
regions described herein, including the reduced-durability region 1330
illustrated in Figure
13 and described above. In some embodiments, the appliance may be in the form
of a
plurality of ring elements 1510 (such as two or more) having cross-sections
1515 that
provide an interface 1517 between the ring elements 1510. For example, two
ring
-25-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
elements 1510 may each have a triangular cross-section 1515 with a base edge
1516, and
the base edges 1516 may be positioned adjacent to each other to form the
interface 1517
between corresponding faces of the ring elements 1510. The base edges 1516 may
be
joined together with an adhesive or matrix material, or they may not be joined
together at
all. The triangular cross-sections 1515 may be sized to generally occupy the
entirety of
the wall 1500 between the skins 210, 220, or they may be sized to occupy only
a portion of
the wall 1500, such as 25% of the wall thickness t. Accordingly, the gap
region 260 may
include some plies 250 with discontinuities and some plies 250 that do not
have
discontinuities in the gap region 260 (through-plies).
[0064] Embodiments with interfaces between a plurality of rings (such as
the ring
elements 1510) or between other portions of appliances, such as the interface
1517
illustrated in Figure 15, may include a bond between the base edges 1516 at
the interface
1517 that is weaker than a bond between the ring elements 1510 and the
surrounding
composite matrix or resin material. In such embodiments, there is a reduced
risk of
delamination between plies 250 along the X-axis due to the tendency of the
bond at the
interface 1517 to break before delamination occurs. Accordingly, the bond at
the interface
1517 may break before the bat gains performance.
[0065] In some embodiments, the faces of the rings or other appliances in
contact
with each other at the interface 1517 may be partially or completely coated
with, treated
with, or otherwise include a release material or a bond-resistant material to
resist bonding
with the composite matrix in the wall and to control the strength of the bond
at the interface
1517. In some embodiments, the faces of the rings or other appliances may be
bonded to
each other using a full or partial coating or treatment of adhesive having a
selected bond
-26-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
strength, so that the interface 1517 includes a bond of adhesive, release
material, or a
combination of adhesive and release material distributed in portions of the
interface. For
example, a bat designer may select the amount and position of adhesive and
release
material to tailor the bond strength at the interface 1517, such as making the
bond strength
at the interface 1517 lower than the strength of the surrounding matrix bond
with the
appliances. In a particular example, a cyanoacrylate or other epoxy resin may
be selected
to provide lower bond strength in the interface 1517 than the bond strength
between the
appliances and the surrounding composite matrix material in the wall.
[0066] Although Figure 15 illustrates an interface 1517 that is oriented
at a non-
parallel angle relative to the Z-axis, the interface 1517 may be oriented at
any suitable
angle. For example, the interface 1517 may be parallel to the Z-axis, in which
case the
ring elements 1510 may have square or rectangular cross-sections.
[0067] Figure 16 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1600 in the straight section 160 of the bat 100 having a reduced-
durability
region 1630 according to another embodiment of the present technology. The
reduced-
durability region 1630 in Figure 16 is generally similar to the other reduced-
durability
regions described herein, but with an alternative arrangement of appliances.
In some
embodiments, a pair of ring elements 1610 may be positioned inside the wall
1600
between the skins 210, 220 and facing each other, such as abutting each other
at an
interface 1617. The interface 1617 may be similar to the interface 1517
described above
with regard to Figure 16, such that it may be fully or partially coated with
adhesive or
release material depending on the bond strength desired by a designer.
-27-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
[0068] In some embodiments¨instead of or in addition to adhesive or
release
material¨the interface 1617 may include a plurality of connecting elements
1620
distributed around the circumference of the barrel wall 1600. In some
embodiments, the
connecting elements 1620 may include thread positioned and configured to hold
the ring
elements 1610 together along the X-axis but configured to fail in shear (along
the Z-axis)
under stresses associated with ABI protocol. In some embodiments, the
connecting
elements 1620 may include pins formed from a rigid or semi-rigid material. The
connecting elements 1620 may be formed with metal, plastic, composite resin
matrix,
thread (such as cotton, nylon, or other thread material), wood, or other
materials suitable
for providing a connection between the ring elements 1610 in the interface
1617. In
another embodiment, connecting elements may be integral with the rings or
appliances.
[0069] For example, Figure 17 illustrates a cross-sectional view of an
embodiment of
a ring element 1700 that may be used as an appliance in a reduced-durability
region, such
as the reduced-durability region 1630 in Figure 16. The ring element 1700 may
include
connecting elements in the form of a groove 1710 and a protrusion 1720, so
that a plurality
of rings 1700 (such as two or more) may be stacked or nested. The protrusion
1720 in a
first ring element 1700 may be positioned in a groove 1710 of a second ring.
The
protrusion 1720 in the groove 1710 provides a shear interface that functions
similarly to the
connecting element 1620 described and illustrated above with regard to Figure
16. For
example, the protrusion 1720 may be configured to break or shear off when
stresses in an
ABI procedure are applied to a bat wall, at a lower stress than stresses that
cause
adjacent composite laminate plies to delaminate. In some embodiments, instead
of an
integral protrusion 1720, a thin ring of material with selected strength may
be attached to
-28-
140670295. 1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
each ring element 1700. In some embodiments, such a thin ring of material, or
the
protrusion 1720, may be, but need not be, continuous around a circumference of
the ball
bat. For example, the thin ring of material or the protrusion 1720 may be
segmented to
further tailor the shear strength between the rings 1700 in a reduced-
durability region.
[0070] Figure 18 illustrates a partial cross-sectional view of a portion
of a composite
barrel wall 1800 in the straight section 160 of the bat 100 having a reduced-
durability
region 1830 according to another embodiment of the present technology. The
reduced-
durability region includes a gap region 260 between the stacks 240 of plies
250. There
may be one or more appliances positioned in the gap region 260, according to
various
embodiments described above. Additionally or alternatively, an appliance may
be in the
form of a through-ply 1810 positioned in the stacks 240 of plies 250, such
that the gap
region 260 does not extend a full thickness of the barrel wall 1800 between
the inwardly
facing skin 210 and the outwardly facing skin 220. Any number of through-plies
1810 may
be positioned in the barrel wall 1800. The through-ply or through-plies 1810
further
facilitate tailoring the strength of the reduced-durability region 1830. For
example, a
through-ply may strengthen the gap to delay delamination during an ABI
process. The
through-plies 1810 may be formed from any suitable composite material,
including those
described above.
[0071] Figure 19 illustrates an appliance in the form of a ring element
1900 having a
t-shaped cross-section, according to an embodiment of the present technology.
The ring
element 1900 may otherwise be similar to other ring elements illustrated and
described
herein. The t-shaped ring element 1900 provides a different surface area and
different
-29-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
bond characteristics with the surrounding composite matrix material to
facilitate a further
option for tailoring the strength of a reduced-durability region.
[0072] In embodiments of the present technology that implement ring
elements, the
ring elements may be positioned in the bat wall during the composite laminate
layup
process. For example, an inwardly facing skin 210 may be wrapped around a
mandrel,
followed by one or more composite laminate plies 240. During the assembly
process, a
ring element may be slid onto the assembly or otherwise positioned around the
mandrel
within the composite layup. Then other layers, such as composite laminate
plies 240, may
be positioned adjacent to or on top of the ring element, followed by the
outwardly facing
skin 220, after which the structure may be cured. In some embodiments, pre-
preg
composite laminate material may be used. In other embodiments, resin transfer
molding
(RIM) processes may be used, in which laminate plies 240 are impregnated with
resin
after being laid up around the mandrel. Other assembly processes may be used
in
accordance with embodiments of the present technology. For example, the
inwardly
facing skin 210, the outwardly facing skin 220, or both skins, may be omitted.
[0073] Although Figures 2-8, 10-16, and 18 illustrate space between
various layers
and appliances, in some embodiments the layers and components of embodiments
of the
present technology may be in generally intimate contact (via any resin or
adhesive
employed in the various embodiments).
[0074] Embodiments of the present technology provide reduced-durability
regions to
deter or discourage bat alteration. For example, if a user attempts to roll or
perform other
ABI processes, stresses in the bat wall will be focused along the gap between
composite
stacks rather than between the plies in the stacks, which will cause the wall
of the bat to
-30-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
fail (destroying the bat) before significant delamination occurs that would
otherwise
improve performance. In addition, the present technology may provide a visual
or tactile
indicator of a failure of the bat wall prior to delamination (if any) between
plies.
Accordingly, the present technology allows for improved testing, improved
indication of bat
failure, and it may deter players from attempting to alter a bat.
[0075] From the foregoing, it will be appreciated that specific
embodiments of the
disclosed technology have been described for purposes of illustration, but
that various
modifications may be made without deviating from the technology, and elements
of certain
embodiments may be interchanged with those of other embodiments, and that some
embodiments may omit some elements. For example, in various embodiments of the
present technology, more than one separation ply may be used, or separation
plies may
be omitted. One or more cap ply elements (such as cap ply elements 310) may be
omitted. Through-plies may be positioned within the composite laminate wall
between
appliances or between appliances and the skins 210, 220.
[0076] Several embodiments of the present technology are described and
illustrated
as having inwardly facing skins (for example, inwardly facing skins 210, 610
described
above) or outwardly facing skins (for example, outwardly facing skins 220,
620), or both
inwardly and outwardly facing skins, which may cover the appliances (such as
separation
plies 270, cap ply elements 310 or 750, appliances in the form of ring
elements, or other
appliances). However, in some embodiments, inwardly facing skins, outwardly
facing
skins, or both inwardly and outwardly facing skins may be omitted, such that
the
appliances form part of an outermost layer of a barrel wall or are exposed to
the hollow
-31-
140670295.1
CA 3053266 2019-08-27
Attorney Docket No. 113507-8134.US00
interior of a bat, the outside environment of a bat, or both. In some
embodiments, one or
both of the cover layers 650 covering the gap region 260 in Figure 6 may be
omitted.
[0077]
Further, while advantages associated with certain embodiments of the
disclosed technology have been described in the context of those embodiments,
other
embodiments may also exhibit such advantages, and not all embodiments need
necessarily exhibit such advantages to fall within the scope of the
technology.
Accordingly, the disclosure and associated technology may encompass other
embodiments not expressly shown or described herein, and the invention is not
limited
except as by the appended claims.
-32-
140670295.1
CA 3053266 2019-08-27
