U.S. patent application number 09/736525 was filed with the patent office on 2002-06-13 for ball bat with thinner handle than barrell.
Invention is credited to Feeney, Brian P..
Application Number | 20020072439 09/736525 |
Document ID | / |
Family ID | 24960217 |
Filed Date | 2002-06-13 |
United States Patent
Application |
20020072439 |
Kind Code |
A1 |
Feeney, Brian P. |
June 13, 2002 |
Ball bat with thinner handle than barrell
Abstract
A tubular metal bat, such as a baseball bat or softball bat,
which includes a handle knob to aid in gripping of the bat, a small
diameter handle portion, an intermediate tapering portion, a large
diameter impact portion, and an end cap. The tubular metal bat
having a wall thickness in the handle area that is significantly
less than the wall thickness in the impact portion of the bat.
Inventors: |
Feeney, Brian P.; (East
Windsor, CT) |
Correspondence
Address: |
Brian P. Feeney
19 Treetop Lane
E. Windsor
CT
06016
US
|
Family ID: |
24960217 |
Appl. No.: |
09/736525 |
Filed: |
December 13, 2000 |
Current U.S.
Class: |
473/566 |
Current CPC
Class: |
A63B 59/51 20151001;
A63B 2102/18 20151001; A63B 59/50 20151001; A63B 2102/182
20151001 |
Class at
Publication: |
473/566 |
International
Class: |
A63B 059/06 |
Claims
What is claimed:
1. A bat, comprising: (a) A tubular metal bat shell having a
cylindrical handle portion, a cylindrical hitting portion, and a
tapered portion coupled to, and extending between the handle and
hitting portions. The diameter of the hitting portion being larger
than the handle portion. (b) Said bat shell having a wall thickness
in the handle area that is significantly less than the wall
thickness in the impact portion of the bat.
2. The bat of claim 1, wherein the ratio of the wall thickness in
the handle area of the shell to the wall thickness in the impact
portion of the shell is less than 0.95.
3. The bat of claim 1, wherein the ratio of the wall thickness in
the handle area of the shell to the wall thickness in the impact
portion of the shell is less than 0.75.
4. The bat of claim 1, wherein the ratio of the wall thickness in
the handle area of the to the wall thickness in the impact portion
of the shell is less than 0.6.
5. The bat of claim 1, wherein the thickness of the handle is less
than 0.040 inches.
6. The bat of claim 1, wherein the thickness of the handle is less
than 0.030 inches.
7. The bat of claim 1, wherein the bat shell is made of a metal
with a yield strength greater than 220 ksi.
8. The bat of claim 1, wherein the bat shell is made of a metal
with a yield strength greater than 260 ksi.
9. A bat comprising: (a) A tubular metal bat shell having a
cylindrical handle portion, a cylindrical hitting portion, and a
tapered portion coupled to, and extending between the handle and
hitting portions. (b) A handle area wall thickness of said bat
shell being less than 0.040 inches. (c) The bat shell constructed
of a metal with a yield strength greater than 250 ksi.
10. A bat, comprising: (d) A tubular metal bat shell having a
cylindrical handle portion, a cylindrical hitting portion, and a
tapered portion coupled to, and extending between the handle and
hitting portions. The diameter of the hitting portion being larger
than the handle portion. (e) A handle area wall thickness of said
bat shell being less than 0.040 inches. (f) The bat shell
fabricated such that the ratio of the wall thickness in the handle
area of the bat shell to wall thickness in the impact portion of
the bat shell is less than 0.075. (g) The bat shell is constructed
of a maraging steel alloy with a yield strength greater than 250
ksi.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
BACKGROUND OF THE INVENTION AND PRIOR ART
[0002] 1. Field of Invention
[0003] This invention relates to a tubular metal bat, such as a
baseball bat or softball bat, which includes a handle knob to aid
in gripping of the bat, a small diameter handle portion, an
intermediate tapering portion, a large diameter impact portion, and
an end cap. The tubular metal bat having a wall thickness in the
handle area that is significantly less than the wall thickness in
the impact portion of the bat.
[0004] 2. Description of Prior Art
[0005] Hollow metal bats of aluminum have been developed and have
been in use for many years when playing baseball or softball.
Improvements and developments have been made in the construction of
hollow metal bats since their introduction. Many of the concepts
for prior art bats fall into two categories. One category could be
summarized as improved single walled bats. These bats have an
impact portion of the bat that is made from a tube composed of one
material with a generally uniform wall thickness. U.S. Pat. No.
5,626,050 of Ploughe summarizes the standard swaging process used
to produce a hollow aluminum bat and further teaches an improved
method in which an inner mandrel is used to better control wall
thickness throughout the bat. Due to the nature of the swaging
process used to manufacture bats, if Phoughe's inner forming
mandrel is not used, the wall thickness of the bat increases as the
bat diameter decreases. Thus the wall thickness would be a minimum
in the impact portion of the bat and maximum in the handle area of
the bat. Ploughe teaches a method that allows the reduction of the
wall thickness in the trumpet, or transition area, and the handle
area with the objective to form metal ball bats with an increased
uniformity in wall thickness throughout the bat. Descriptions of
other single wall bats and improvements to such bats are described
in U.S. Pat. No. 5,393,055 of MacKay, U.S. Pat. No. 5,421,572 of
MacKay, U.S. Pat. No. 5,494,280 of MacKay, and U.S. Pat. No.
5,785,614 of MacKay. The improvements in these patents relate to
improved designs for end caps or methods of providing a
concentrated end weighting, or end loading, to adjust the weight
and balance of such a bat.
[0006] The second category of patents could be summarized as multi
walled bats. Multi walled bats have a barrel area that utilize two
tubes of the same or differing materials. The second wall is
designed to improve both the durability and liveliness of the bat.
Both walls are generally in contact, but may or may not be bonded
to one another. U.S. Pat. No. 1,611,858 of Middlekauff, U.S. Pat.
No. 5,364,095 of Easton, U.S. Pat. No. 5,415,398 of Eggiman, U.S.
Pat. No. 5,676,610 of Bhatt, U.S. Pat. No. 5,899,823 of Eggiman,
U.S. Pat. No. 6,042,493 of Chauvin, and U.S. Pat. No. 6,053,828 of
Pitsenberger all disclosure bats that have multiple walls in the
barrel area of the bat. Other patents of note that do not fall
directly into either the single wall or multi wall categories are
U.S. Pat. No. 3,963,239 of Fujii, U.S. Pat. No. 4,241,919 of
Foreman, U.S. Pat. No. 5,954,602 of Eggiman and U.S. Pat. No.
6,053,827 of MacKay.
[0007] Few of the prior art patents provide details on the wall
thickness in the handle area of the bat relative to the wall
thickness in the impact portion of the bat. Destructive examination
of several commercially available single wall aluminum softball
bats composed of C-405 aluminum from Alcoa of Pittsburgh, Pa.
indicates that the average handle thickness is between 0.090 to
0.130 inches thick and that wall thickness in the impact portion of
the bat is between 0.065 to 0.080 inches thick. The wall thickness
of an aluminum outer shell in bats produced according Eggiman in
U.S. Pat. No. 6,042,493 were found to be in the range of about
0.085 to 0.110 inches in the handle area and 0.040 to 0.055 inches
in the barrel area.
[0008] Despite the advances claimed in these patents, today's
supposedly high performance bats are still susceptible to denting.
While the more durable bats are not sufficiently compliant and do
not perform well. The number of individual components used in the
manufacture the higher performance multi wall bats complicates the
manufacturing process, thus increasing the cost to produce them.
The use of a high density metal, like a maraging steel alloy, to
form the entire bat shell is a radical departure from the
significantly lower density aluminum alloys, or titanium alloys,
that have exclusively been used in commercial metal bats within the
last twenty to thirty years. Neither prior art patents or
commercially available bats, nor any combination thereof suggest
the unobvious invention of single wall metal bat in which the ratio
of the thickness of the wall thickness in the handle of the bat to
the wall thickness in the impact portion, or barrel, of the bat is
significantly less than one.
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide a bat with
improved performance and with a minimum number of components. The
present invention relates to a tubular bat, which includes a handle
knob to aid in gripping of the bat, a small-diameter handle
portion, an intermediate tapering portion, a large diameter impact
portion, and an end cap. The bat of the invention has a wall
thickness in the handle area that is significantly less than the
wall thickness in the impact portion of the bat. The bat is ideally
formed of a high strength steel alloy.
OBJECTS & ADVANTAGES
[0010] The object and advantages of the present invention are
[0011] (a) to provide a bat with a wall thickness in the handle of
the bat that is less than wall thickness in the impact portion of
the bat;
[0012] (b) to provide a bat with maximum performance and durability
without the added complication of a multi wall construction in the
impact portion of the bat;
[0013] (c) to provide a bat shell composed a metal with a density
significantly higher than the aluminum alloys commonly used;
[0014] (d) to provide a bat shell with a balance point that is
further away from players hands than currently available single
wall bat shells;
[0015] (e) to provide a single wall bat in which the need for and
the amount of end load material used in each bat is reduced due to
the higher balance point of the bat shell;
[0016] (f) to provide a method for producing a bat with a reduced
number of components and manufacturing operations;
[0017] (g) to provide a bat with improved performance at a reduced
cost.
[0018] The foregoing and additional features and advantages of the
present invention will be more readily apparent from a
consideration of the ensuing description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a side view of a bat of the present invention.
[0020] FIG. 2 is section view taken along 2-2 of FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0021] Referring to FIG. 1 a bat 10 representative of the newly
invented bat. Said bat has a handle knob 18, a small diameter
handle area 12 of generally uniform outer diameter, the handle is
covered by a synthetic or natural leather grip 20, an intermediate
transition zone 14 tapers up to a hitting zone 16 of a generally
constant outer diameter, and at the distal end of the bat an end
cap 22 is inserted into the hitting zone. The hollow metal tube
consisting of the handle area 12, the transition area 14, and the
hitting zone 16 will be referred to as the bat shell 30.
[0022] FIG. 2 is section view taken along 2-2 of FIG. 1. This view
shows a bat shell 30 having a single wall, an end cap 22, and an
end load 24. The end cap 22 can be made from many types of
materials including metals, composites, or plastics. The end cap is
preferably made using an injection molding process and is composed
of a thermoplastic material. Softball bat models are commonly sold
in a range of weights to accommodate different players strengths
and preferences. Thus a single model of a bat may be sold in 26,
27, 28, 29, 30, 31, and 32 ounce versions. To produce bats in the
various weights the same bat shell design will be used in
conjunction with different end loads and or end caps.
[0023] To complete the manufacture of this bat, the end cap is
inserted into the bat shell and secured using an adhesive and or
mechanical locking mechanism. The end load is created using a
curable two component liquid urethane and is cast into the shell of
the bat by pouring it down through the handle area of the bat that
has been positioned vertically with the end cap at the bottom. The
end load settles at the bottom of the bat inside the end cap and a
portion of the hitting zone, where it hardens into place. Once the
urethane hardens the handle knob of the bat is attached to the bat
by a welding process. Lastly a grip is wrapped around the handle
portion of the bat. These finishing operations are the same as used
on commercially available single wall aluminum bats.
[0024] To produce a bat according to the present invention wherein
the wall thickness in the barrel area of the bat is significantly
thicker than wall thickness in the handle of the bat it is
desirable to use a very high strength material to assure maximum
strength and durability of the bat. If one tried to make a bat
according to the present invention using one of the commonly used
aluminum alloys, the bat would either lack liveliness or
durability. Using any aluminum alloy, a handle area wall thickness
of about 0.090 inches or greater is preferred to prevent failure in
the handle area. If one were make a bat according to the current
invention using an aluminum alloy with a sufficiently durable
handle design, then the wall thickness in the barrel area would
need to be significantly greater than 0.090 inches. This would
result in a bat with poor performance because the barrel area would
be too stiff and limit the trampoline effect of the bat. To
maximize the liveliness of an aluminum bat the wall thickness in
the impact portion of the bat needs to be less than 0.080 inches
and preferably between 0.065 and 0.075 inches. An aluminum bat
according to the present invention then would have a handle wall
thickness less than 0.080 inches and result in bat that breaks or
permanently deforms in the handle of the bat.
[0025] Thus to make a bat that meets the requirements of the
present invention requires a material with a significantly higher
strength than aluminum and thus allows a thin walled handle to be
of sufficient strength. Several such steel alloys meet this
requirement, including C-250, C-300, C-350, T-250, T-300 maraging
steel available from Allvac located in Monroe, N.C. Other steel
alloys that have the desired physically properties include AerMet
100 and AerMet 310 available from Carpenter Specialty Alloys in
Wyomissing, Pa. When properly utilized these steel alloys can
obtain yield strengths that are greater than 250 ksi.
[0026] Attempts to use swaging equipment and tooling used to swage
aluminum alloys into softball bats with steel alloys were
unsuccessful. During the swaging process the steel alloys work
hardened much quicker than aluminum alloys. As attempts were made
to reduce the diameter of the tube, the steel hardened, became
brittle and eventually fractured. The swaging trials that were
tried attempted to form the entire shell in a single step. It may
be possible to swage steel alloys into bats if the swaging process
were performed in a series of steps. During each step the tube
diameter would be reduced in the appropriate areas of the bat until
the work hardening limit is reached. At the point the shell would
be removed from the swaging machine and heat-treated to relieve the
stresses in the metal. The process would then be repeated as many
times as required to form the entire bat into the desired
configuration. The process of repeatedly removing the partially
formed bat from the swaging machine and heat-treating would likely
make this process to expensive to produce a commercially viable
bat.
[0027] Two companies that have processes that can produce bat
shells to the desired configuration are Dynamic Machine Works Inc.
located in Billerica, Mass. and LeFiell located in Sante Fe
Springs, Calif. These companies utilize manufacturing processes
that reduce the amount of work hardening that occurs when the bat
is formed. This allows bat shells to be manufactured in as few as
one forming operation. The manufacturing process that would be
optimally be used to produce a bat shell according to this
invention can in its most general sense be referred to as a
spinning operation.
[0028] One other way to produce bat shells using maraging steels
would be to form the handle area, the tapered area, and the impact
area of the bat in three separate tubes. The three tubes could then
be welded together to form the full bat shell. This method may not
be suitable for production quantities of bats, but would be
suitable for the manufacturing and evaluation of prototype bats in
which the wall thickness in a particular section of the bat is
varied to determine the effect on performance and durability.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0029] The foregoing detailed description is given primarily for
clearness of understanding and no unnecessary limitations are to be
understood therefrom for modifications will become obvious to those
skilled in the art upon reading this disclosure and may be made
without departing from the spirit of the invention or the scope of
the appended claims. One obvious variation would be to increase or
decrease the wall thickness of the bat shell in a localized region.
This might be done to aid in securing of the handle knob or end
cap, or in an attempt to work around the claims of this
invention.
* * * * *