U.S. patent application number 09/891996 was filed with the patent office on 2002-02-07 for baseball or softball bat.
Invention is credited to Misono, Kazunori, Okuyama, Masaaki.
Application Number | 20020016230 09/891996 |
Document ID | / |
Family ID | 18693007 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020016230 |
Kind Code |
A1 |
Okuyama, Masaaki ; et
al. |
February 7, 2002 |
Baseball or softball bat
Abstract
A sweet spot 3 of an impact portion 2 has a smaller diameter
than the other portions of the impact portion 2, whereby the impact
portion 2 has an intermediate tapering shape in the longitudinal
direction. Thus, even if hit with a portion at some distance from
the sweet spot, rebound performance is not significantly reduced.
Therefore, a bat having a large sweet area and capable of reducing
the occurrence of foul balls is obtained.
Inventors: |
Okuyama, Masaaki; (Osaka,
JP) ; Misono, Kazunori; (Osaka, JP) |
Correspondence
Address: |
TROUTMAN SANDERS LLP
BANK OF AMERICA PLAZA, SUITE 5200
600 PEACHTREE STREET , NE
ATLANTA
GA
30308-2216
US
|
Family ID: |
18693007 |
Appl. No.: |
09/891996 |
Filed: |
June 26, 2001 |
Current U.S.
Class: |
473/564 |
Current CPC
Class: |
A63B 59/50 20151001;
A63B 2102/18 20151001; A63B 59/58 20151001; A63B 2102/182
20151001 |
Class at
Publication: |
473/564 |
International
Class: |
A63B 059/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2000 |
JP |
2000-194132(P) |
Claims
What is claimed is:
1. A baseball or softball bat, wherein a sweet spot of an impact
portion has a smaller diameter than other portions of said impact
portion, and said impact portion has a recessed outer shape in a
longitudinal direction.
2. The baseball or softball bat according to claim 1, wherein an
outline of a recessed part of said impact portion includes a
curve.
3. The baseball or softball bat according to claim 2, wherein the
outline of the recessed part of said impact portion is part of an
arc or ellipse.
4. The baseball or softball bat according to claim 3, wherein the
outline of the recessed part has a curvature radius of 200-1000
cm.
5. The baseball or softball bat according to claim 1, wherein the
diameter of said impact portion increases from said sweet spot
toward a leading edge and grip end of said bat.
6. The baseball or softball bat according to claim 1, wherein the
outline of the recessed part of said impact portion includes a
straight line.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an improvement of a
baseball or softball bat hereinafter referred to as a bat). The
present invention provides a high-performance bat having a large
sweet area that can achieve a good slugging distance even when a
ball is hit with a portion other than a sweet spot, by forming the
outer shape of the impact portion of the bat to have an
intermediate tapering portion or recessed portion in the
longitudinal direction.
[0003] 2. Description of the Background Art
[0004] The greater diameter of an impact portion tends to provide a
smaller stiffness for elliptic deformation and hence give higher
rebound performance to a ball. Then, it is generally known that a
bat which gives excellent rebound performance can be effectively
designed by making the diameter of an impact portion as large as
possible.
[0005] On the other hand, if the diameter of the impact portion is
too large, the bat becomes too heavy for a hitter to take a
comfortable swing. If such a large diameter is to be maintained
with less weight, sufficient strength is not obtained.
[0006] Then, to give improved rebound performance to the
conventional bat, it has been necessary to reduce the impact
portion in length so that the diameter of the impact portion is
made large with less weight. As such, the conventional bat has a
small sweet area.
[0007] As shown in FIG. 4, the conventional bat has an impact
portion having a perimeter of a linear or gentle convex curve in
the longitudinal direction. Thus, if a right-handed batter hits a
rather outside ball with the impact portion near a leading edge,
the stroke may result in a foul ball on the first base side.
[0008] On the other hand, if a right-handed batter hits a rather
inside ball with the impact portion near a grip end, the stroke may
result in a foul ball on the third base side.
SUMMARY OF THE INVENTION
[0009] Therefore, the present invention aims at providing a bat
which has such a large sweet area that a certain level of rebound
performance is ensured even if a ball is hit with a portion at some
distance from a sweet spot, and which may reduce the occurrence of
foul balls.
[0010] The baseball or softball bat of the present invention
includes an impact portion which has a smaller diameter at a sweet
spot than at the other locations of the impact portion, and which
has a recessed external shape in the longitudinal direction.
[0011] The outline of a recessed part of the impact portion may be
a curve, straight line, arc, or ellipse. The perimeter of the
recessed part has a curvature radius of 200-1000 cm.
[0012] Preferably, the diameter of the impact portion increases
from the sweet spot toward the leading edge and grip end of the
bat.
[0013] The foregoing and other objects, features, aspects and
advantages of the present invention will become more apparent from
the following detailed description of the present invention when
taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a plan view of a bat according to the present
invention.
[0015] FIG. 2 is a plan view of a bat according to another
embodiment of the present invention.
[0016] FIG. 3 is a graph showing a comparison result of rebound
performance between the bat of the present invention and the
conventional bat.
[0017] FIG. 4 is a plan view of the conventional bat.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Now, the embodiment of the present invention will be
described.
[0019] Referring to FIG. 1, a bat 1 of the present invention has a
smaller diameter at a sweet spot 3 of an impact portion 2 that
gives the maximum bounce to a ball than at the other locations of
impact portion 2. Impact portion 2 has a recessed outer shape. More
specifically, impact portion 2 has a perimeter of an intermediate
tapering shape in the longitudinal direction.
[0020] The recessed shape is obtained with the diameter of impact
portion 2 being minimum at the location of sweet spot 3 and
gradually increasing toward a leading edge 4 and a grip end 5 of
bat 1. Thus, even if hit with the portion other than sweet spot 3,
bat 1 has a large sweet area and exhibits less reduction in rebound
performance because of the larger diameters of impact portion
2.
[0021] The outline of the recessed portion is desirably part of a
curve, and especially an arc or ellipse with a curvature radius of
200-1000 cm. However, it may be part of a straight line as shown in
FIG. 2.
[0022] Bat 1 can be made of various materials including wood,
metal, fiber reinforced plastic (FRP) and the like. Bat 1 of the
present invention can be made of any material.
[0023] If made of wood, bat 1 is formed by turning, followed by
reinforcement by resin injection or the like.
[0024] If made of metal, bat 1 is formed by the conventional
manufacturing method and then processed to have a tapering impact
portion 2 with use of a metal roller or the like.
[0025] If made of FRP, for example, bat 1 is formed to have a
tapering impact portion 2 with use of a mold having the
corresponding shape.
[0026] Bat 1 does not necessarily have to be formed of a single
material, but may be formed of different materials. For example, a
tapering tubular member of FRP may be used for impact portion 2 of
metal bat 1, or a tapering metal tubular member may be used for
impact portion 2 of FRP bat 1.
[0027] Table 1 and FIG. 3 show a comparison result of rebound
performance between baseball bat 1 of the present invention shown
in FIG. 1 and conventional baseball bat 1 shown in FIG. 4.
1 Present invention Conventional example Distance from Diameter
Rebound Diameter Rebound grip end (mm) (mm) Coefficient (mm)
Coefficient L1 480 69.0 0.560 63.0 0.480 L2 580 64.5 0.585 63.0
0.560 L3 680 63.0 0.600 63.0 0.600 L4 780 64.5 0.580 63.0 0.550
[0028] As is apparent from the above result, sweet spot 3 (portion
about 680 mm from the grip end) exhibits the highest rebound
(restitution) coefficient, and the rebound coefficient decreases as
away from sweet spot 3.
[0029] Although conventional bat 1 exhibits a considerable decrease
in rebound coefficient as away from sweet spot 3, bat 1 of the
present invention exhibits only a slight decrease in rebound
coefficient because of the increasing diameter of the impact
portion, having a large sweet area.
[0030] In the present invention, the diameter of the impact portion
at the sweet spot is minimum and then the diameter gradually
increases toward the leading edge and grip end of the bat. Thus, if
hit with the portion other than the sweet spot, the decrease in
rebound performance is not considerable because of the increasing
diameter of the impact portion. As such, the bat has a large sweet
area.
[0031] Further, the intermediate tapering shape of the impact
portion helps the ball hit with the end of the impact portion to be
directed to a fair zone. Thus, the occurrence of foul balls and
hence game length are reduced.
[0032] Although the present invention has been described and
illustrated in detail, it is clearly understood that the same is by
way of illustration and example only and is not to be taken by way
of limitation, the spirit and scope of the present invention being
limited only by the terms of the appended claims.
* * * * *