Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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A Cricket Sports Bat
The present invention provides a cricket sports bat comprising an elongate
handle and
a truncate blade having a larger hitting sweet spot.
Background of the Invention
A variety of sports use bats of various different shapes to strike a ball. The
present
invention relates to those bats that comprise a handle, one end of which is
connected
to a truncate blade.
In the following description the invention will be described with reference to
a cricket
bat. The general shape of cricket bats has remained standard for many years.
The
shape of cricket bats has been standard and little changed for the best part
of 150
years. Today's bats are almost identical in blade shape to those that were
produced
well over a century ago. Very few attempts have been made over the course of
time to
adjust the width of the blade of a cricket bat.
One feature that has remained constant has been the shape of the profile of
the front
playing face of the bat. The blade is generally rectangular in shape except
for the
shoulders near the point where the blade and handle join. Often the edges of
the front
face are beveled or rounded slightly to prevent splintering of the bat along
its edges.
Another feature that has been little changed has been the balance point, pick
up, of the
bat.
Traditionally cricket bats have been made of willow and the handle is spliced
into the
blade. The rear surface of the bat has traditionally been shaped to be convex
in cross
section and/or V shaped. In these bats, the thickness of the blade decreases
away
from the point of maximum thickness both towards the sides and towards the toe
and
also towards the shoulders in such a way that that the rear surface of many
bats has a
central line extending down most of the length of the rear surface. Cricket
bats have
been symmetrical about a central plane running through the centre of the bat
(handle
and blade) perpendicular to the front playing surface. The central line of the
V (splice)
is located on the plane of symmetry of the blade. The rear surface of the
blade has
been shaped so that the maximum thickness and hence mass is situated at a
point
approximately 15 cm from the toe concentrated around the plane of symmetry in
the
central section of the back surface. This provides a "sweet spot", that is the
optimum
location for bat/ball contact to obtain the most effective hit in terms of
distance and
direction of travel of the ball relative to the work done by the player using
the bat to
strike the ball. The sweet spot on the front playing face is the striking area
opposite the
location of the maximum mass on the rear surface.
Bat shapes to date have restricted the sweet spot to a small area. The effect
of the
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impact of a ball against the front face of the bat to either side of the point
where the
central plane intersects the playing surface is to try to turn the bat about
its longitudinal
axis so that a misdirected or week hit results.
Impact of the ball on the front playing face at a point between the handle and
the sweet
spot results in the ball being lifted with a higher trajectory than desired,
and the force
delivered to the ball being weaker, with the result that there is a greater
risk in the
batsman being caught. Impact of the ball on the front playing face at a
position
between the sweet spot and the toe results in the ball being imparted a lower
trajectory
than desired, and a short hit results.
A standard cricket bat may not be more than 96.5 cm in length and 10.8 cm at
its
widest part. A standard bat cricket bat has a blade with a total length of
between 54
and 57 cm, usually about 55.5 cm.
One of the aims of a bowler is to cause the batsman to strike the ball
adjacent the edge
of the bat, causing the ball to be deflected to a fielder. This is achieved by
causing the
ball to swing in the air or to turn off the pitch. Other methods used include
causing the
ball to bounce sharply and/or bowling very quickly so that the batsman does
not have
time to fully coordinate his movements to strike the ball cleanly One of the
greatest
risks to a batsman staying in the game is when he strikes the ball on the edge
of the
bat above the sweet spot of a traditional bat as this not only causes the ball
to be
deflected but it also causes the ball to rise with a higher trajectory and
less speed.
There is therefore a greater risk of him being caught.
Various attempts have been made at redesigning bats to overcome the aforesaid
problems.
In UK Patent 1391120, Messrs Wheeler and Garner describe a bat in which the
rear
surface has been depressed in such a way that the maximum thickness of the
blade is
adjacent the side of the blade and is thinnest towards the central plane so
that instead
of the maximum weight and mass being concentrated largely behind the central
plane
about one spot it is distributed around the rim and towards the toe and
shoulder of the
blade to allegedly provide a sweet spot whose area is allegedly considerably
extended.
In UK Patent 1586706, Mr. Garner describes a bat in which the rear surface
again
contains one or more depressions to allegedly provide a sweet spot whose area
is
allegedly considerably extended as in UK 1391120 but also includes a
reinforcing
portion at least partially surrounded by said depression/s, the reinforcing
section being
disposed about the longitudinal axis of the blade in the region of the sweet
spot, the
thickness of the blade at said reinforcing section being greater than the
thickness of
the blade in said depression.
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However, these bats do not provide the same level of power to play a stroke as
standard bats. Standard cricket bats (junior to senior) range from 64.1 cm to
96.5 cm
in length, 8.9 cm to 10.8 cm. Their weigh varies with size. Typically the
blade is 66% of
the length of the whole bat, the handle is 34% of the whole bat length and the
splice/blade (lower handle/upper blade) represents 16.45% of the total bat
length.
Very few manufacturers have made changes in recent history to the front
playing
surface of the blade. Slazenger attempted this in 1985 with the introduction
of the WG
bat that effectively was a shoulder less blade.
Newbery's Excalibur bat was very similar to Slazenger's in that it had a
shoulder less
blade. The profile of both bats was changed to remove the playing surface area
in the
third of the blade closest to the handle as shown in Fig. 1. However, the
problem with
both of these bats was that they reduced the playing area to an unacceptable
level and
removed the shoulders, resulting in a loss of performance.
Prior art bat tried in 2003 with its recessed edged bats but again there was
little benefit
from the slight weight transfer of the recessed edges to the sweet spot.
Summary of the Invention
The present invention overcomes these problems by providing a revolutionary
elongate
handle/blade combined with a truncate front playing face/back of the blade
along and
below the handle and shoulders on both sides as compared to a standard bat.
This
provides a balance between reducing the playing surface area in the top
section of the
blade and maintaining as much as possible of the front playing area in the
lower
portion of the blade for the batsman to be able to affect a normal
defensive/attacking
shot by making contact with the ball. Further, by transferring the mass and
weight of
the wood removed from the upper part of the blade above the shoulders as
compared
to a standard bat to the sweet spot of the bat, functional advantages are
given to the
bat. Providing a bat with a lighter upper third of the blade results in a more
balanced
pick up of the bat and the sweet spot can be made bigger and deeper giving an
extended sweet spot and greater blade speed without adding extra weight to the
bat.
The sweet spot is further extended by taking the splice out off the hitting
area of the
blade and removing the upper dead area of the blade. The splice can be a
standard
M. shape, .W. shape, tooth like dovetail and other splice combinations. By
removing
the top portion of the playing surface this will reduce the number of catches
off that
portion of the bat.
According to the present invention there is provided a cricket sports bat
comprising an
elongate handle and a truncate blade having a much thicker hitting sweet spot,
the
blade comprising a front playing face the majority of which is substantially
planar
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across its face, an opposing rear surface, sides extending between the front
face and
rear surface, a toe and a pair of shoulders/shoulder less extending one each
side of the
handle/blade to the sides, characterized in that the front playing surface is
reduced by
25%-35% with an average of 28.4% above the shoulders (As compared to a
standard
cricket bat).
According to a further preferred aspect of the present invention, there is
provided a
cricket sports bat comprising a handle and a truncate blade having a larger
hitting
sweet spot, the blade comprising a front (handle non-splice or handle spliced)
playing
face the majority of which is substantially planar across its face, an
opposing rear
surface and sides extending between the front face and rear surface, toe and a
pair of
shoulders extending one each side of the blade/handle to the sides,
characterized in
that the front and back upper playing surface has been reduced in size by the
majority
removal of the blade along and below the handle and shoulders on both sides as
compared to a standard bat.
According to a further preferred aspect of the present invention there is
provided a
cricket sports bat comprising an elongate handle and a blade, the blade
comprising a
front playing face, an opposing rear surface, sides extending between the
front face
and rear surface, a toe and a pair of shoulders extending one each side of the
handle/blade to the sides, characterized in that the ratio of the length of
the blade to
the width of the blade is in the range of 4:1-3.25:1. In this aspect, the
blade of the bat
is preferably referred to as a truncate blade (as compared to a standard bat
because
the toe to shoulder length is shorter).
According to a further preferred aspect of the present invention there is
provided a
cricket sports bat comprising an elongate handle and a blade, the blade
comprising a
front playing face, an opposing rear surface, sides extending between the
front face
and rear surface, a toe and a pair of shoulders extending one each side of the
handle/blade to the sides, characterized in that at least 50% of the splice is
incorporated into the handle of the bat.
In these aspects of the invention, the ratio of the length of the blade to the
width of the
blade is preferably in the range of 3.95:1-3.5:1, more preferably, 3.85:1-
3.6:1, more
preferably, 3.8:1-3.65:1, for example, 3.75:1-3.68:1, such as about 3.7:1.
In this regard, the length of the bat is considered to be the length from the
tip of the toe
to the point at which the shoulders of the bat meet the blade, preferably the
widest part
of the blade.
In this regard, the width of the bat is considered to be the width at its
widest point. This
is preferably 10.8 cm, but may be in the range of 9 cm-10.8 cm.
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Preferably, no more than 20% of the blade length is greater than 0.5 cm
narrower than
its widest width (which is preferably about 10.8 cm). More preferably, no more
than
10% of the blade length is greater than 0.2 cm narrower than its widest width
(which is
preferably about 10.8 cm). In a particularly preferred embodiment, greater
than 90% of
the blade length is in the range of 10.5 cm-10.8 cm wide. More preferably,
greater than
95% of the blade length is in the range of 10.6 cm-10.8 cm wide. Even more
preferably, greater than 99% of the blade length is about 10.8 cm wide. In a
particularly preferred embodiment, substantially 100% of the blade length is
10.8 cm
wide.
In a preferred embodiment, the length of the blade is in the range of 35 cm to
43 cm
long, more preferably 37 cm to 42 cm long, more preferably 39 cm to 41 cm
long.
In a particularly preferred embodiment of the invention, the splice of the bat
finishes
above the lowest level of the shoulder of the bat. The lowest level of the
shoulder of
the bat is the point at which is meets the side of the blade. Preferably, the
splice of the
bat finishes at least 1 cm above the lowest level of the shoulder of the bat,
preferably at
least 2 cm above the lowest level of the shoulder of the bat. Preferably, the
splice of
the bat finishes at least 3 cm above the lowest level of the shoulder of the
bat. The
splice preferably finishes between 2.5 cm and 5 cm above the lowest level of
the
shoulder of the bat, most preferably between 3 and 4 cm above the lowest level
of the
shoulder of the bat.
In a particularly preferred embodiment of the invention, the splice of the bat
is
incorporated entirely within the handle and optionally additionally in the
area above the
lowest point of the shoulders of the bat. Preferably, the widest diameter of
the handle
in which the splice is incorporated (and, the area above the lowest point of
the
shoulders of the bat if the splice is incorporated in this part of the bat) is
no greater
than 6.5 cm, more preferably, no greater than 6 cm, more preferably no greater
than
5.75 cm, more preferably no greater than 5.5 cm.
Preferably, the diameter of the widest part of the bat which incorporates the
splice is no
greater than 6.5 cm, more preferably, no greater than 6 cm, more preferably no
greater
than 5.75 cm, more preferably no greater than 5.5 cm.
Preferably, the average diameter of the widest part of the bat which
incorporates the
splice is no greater than 6.25 cm, more preferably, no greater than 5.8 cm,
more
preferably no greater than 5.5 cm, more preferably no greater than 5.25 cm.
Preferably, the part of the bat which incorporates the splice (be it the
handle, optionally
including the shoulder area) has an average diameter of less than 5.5 cm,
preferably
less than 5.25cm, more preferably less than 5 cm, more preferably less than
4.75 cm,
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for example, between 3.5 cm and 4.5 cm, preferably between 3.75 cm and 4.25
cm.
Preferably, at least 55% of the length of the splice is incorporated into the
handle of the
bat, more preferably at least 60%, more preferably at least 70%, more
preferably at
least 75%, more preferably at least 80%, more preferably at least 80%, more
preferably
at least 85%, more preferably at least 90% or at least 95%. In this regard,
the handle is
considered to be the length measured from top of shoulder to the end of the
handle
(for example, the length shown as dimension B in Figure 5A). For the purposes
of this
measurement of this distance, the handle is considered to finish at the point
at which
the average diameter of the handle exceeds 5 cm.
Preferably, at least Preferably, at least 50% of the length of the handle
which
incorporates the splice is wrapped with twine, string or the like. Preferably,
at least
70% of the length of the splice is covered by the twine, string or the like.
Preferably not
more than 4 cm of the bottom of the splice is visible when wrapped by the
twine, string
or the like, more preferably not more than 3.5 cm, more preferably not more
than 3 cm,
more preferably not more than 2.6 cm. In this regard, the handle is considered
to be
the length measured from top of shoulder to the end of the handle (for
example, the
length shown as dimension B in Figure 5A). For the purposes of this
measurement of
this distance, the handle is considered to finish at the point at which the
average
diameter of the handle exceeds 5 cm.
Preferably, none of the splice is incorporated in a part of the bat which has
a largest
diameter of greater than 6.5 cm, preferably no greater than 6 cm, preferably
no greater
than 5.5 cm.
Preferably, none of the splice is incorporated in a part of the bat which has
an average
diameter of greater than 6.5 cm, preferably no greater than 6 cm, preferably
no greater
than 5.5 cm, preferably no greater than 5 cm.
The narrowest part of the handle (including twine (string) binding) is
preferably in the
range of 3-3.5 cm, preferably about 3.25 cm.
A particularly preferred aspect of the present invention is that the twine or
string
binding can be used to reinforce the connection of the blade to the handle of
the bat.
In this regard, because the splice is formed in the handle of the bat, the
binding can be
used to wrap around the wood into which the splice is spliced. This actually
reduces
the likelihood that the splice or the wood to which it is attached will break
when the bat
is used. In standard bats, the spice is merely spliced into the blade and
adhered
thereto with glue. Thus, the present invention provides a significant
advantage over the
splicing of a standard bat.
Preferably, the percentage of the whole length of the bat that has a width of
less than
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10.8 cm is between 50% and 70%, more preferably between 53% and 65%, more
preferably between 54% and 60%, more preferably between 55 and 58%. In this
regard, it should be bourn in mine that the maximum bat length allowed is 96.5
cm.
However, in a preferred embodiment, the length of the bat of the present
invention is
between 83 cm and 87 cm long, preferably between 85 and 86 cm long, most
preferably about 85 cm long.
Preferably, the percentage of the bat length that has a width of less than
4.25 cm is
greater than 40 %, preferably greater than 45%, most preferably between 45 and
48 %.
Preferably, the blade (measured from toe to bottom of shoulder) is between 30%
and
50% of the length of the whole bat, more preferably between 35 % and 48% of
the
whole bat length, more preferably between 43 % and 47.5 % of the whole bat
length,
for example, about 46% thereof.
As used herein, the length of the blade is considered to be the length from
the bottom
of the toe to the bottom of the shoulder (for example, the length shown as
dimension E
in Figure 5A).
Preferably, the ratio of the length of the blade to the length of the handle
(measured
from top of shoulder to end of handle) is in the range of 1:1-1:1.4, more
preferably in
the range of 1:1-1:1:1.3, more preferably in the range of 1:1.05-1:1.1.25,
more
preferably in the range of 1:1.1-1:1.1.2, for example, about 1:1.05, or about
1:1.075, or
about 1:1.1, or about 1:1.125, or about 1:1.15.
As used herein, the length of the handle is considered to be the length
measured from
top of shoulder to end of handle (for example, the length shown as dimension B
in
Figure 5A).
Preferably, the spliced-handle length is in the range of 10 cm to 50.18 cm,
preferably
25 cm to 45 cm, more preferably 30 cm to 45 cm, more preferably 40 cm to 43
cm,
more preferably about 41, 42, 43 or 44 cm long. The `spliced-handle' length is
considered to be the length from the end of the handle to the end of the
splice.
The shoulder width is preferably in the range of 2.5 cm to 4.5 cm, more
preferably 3 to
4.25 cm, more preferably 3.5 to 4 cm. The shoulder width is the distance
measured
from the longitudinal axis created by the outer diameter of the narrowest part
of the
handle and point at which the shoulder meets the side of the blade. The outer
diameter of the handle is taken to be the diameter of the handle including the
twine
winding applied to the handles of most standard cricket bats.
Preferably, the truncate blade of a bat according to the present invention
contains
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between 80 %and 120% of the volume of wood in a standard bat (such a standard
bat
having a blade length of greater than 60%, preferably about 66% of the length
of the
whole bat). More preferably, the truncate blade of a bat according to the
present
invention contains between 90 % and 110% of the volume of wood in such a
standard
bat. More preferably, the truncate blade of a bat according to the present
invention
contains between 95 %and 105% of the volume of wood in such a standard bat.
Preferably, the width of the edges of the blade are in the range of 2.3 cm to
4 cm wide,
more preferably 2.5 to 3.5 cm wide. Preferably, greater than 75% of the width
of the
edges are greater than 2.3 cm wide, preferably greater than 2.5 cm wide, more
preferably greater than 2.75 cm wide. More preferably, greater than 85% of the
width
of the edges are greater than 2.3 cm wide. More preferably, greater than 95%
of the
width of the edges are greater than 2.3 cm wide.
Preferably, the thickness of the blade of the bat (at its widest point) is in
the range of 5
cm to 10 cm, more preferably 5.5 cm to 8 cm, for example about 5.5 cm, about 6
cm,
about 6.5 cm, about 7 cm or about 7.5 cm.
Preferably, greater than 75% of the blade of the bat has a thickness which is
in the
range of 5 cm to 10 cm, more preferably 5.5 cm to 8 cm, for example about 5.5
cm,
about 6 cm, about 6.5 cm, about 7 cm or about 7.5 cm.
Preferably, greater than 85% of the blade of the bat has a thickness which is
in the
range of 5 cm to 7 cm, more preferably 5.5 cm to 6 cm.
Preferably, less than 25% of the blade of the bat has a thickness less than
5.5 cm.
Preferably, the distance between the lowest point of the shoulder (the point
at which
the shoulder meets the side of the blade) and the narrowest diameter of the
handle is
in the range of 3 cm to 15 cm, more preferably less than 12 cm, more
preferably less
than 10 cm, more preferably less than 8 cm, more preferably less than 7 cm,
more
preferably less than 6 cm.
Preferably, the distance between the lowest point of the shoulder (the point
at which
the shoulder meets the side of the blade) and the end of the splice is in the
range of 2
cm to 10 cm, more preferably less than 9 cm, more preferably less than 8 cm,
more
preferably less than 7 cm, more preferably less than 6 cm, more preferably
less than 5
cm.
In a particularly preferred embodiment of the present invention, there is
provided a
cricket sports bat comprising an elongate handle and a blade, the blade
comprising a
front playing face (which is substantially planar across its face), an
opposing rear
surface, sides extending between the front face and rear surface, a toe and a
pair of
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shoulders extending one each side of the handle/blade to the sides,
characterized in
that the ratio of the length of the blade to the width of the blade is in the
range of 4:1-
3.25:1, no more than 5% of the blade length is less than 10.6 cm wide; the
length of the
blade is in the range of 35 cm to 43 cm long; the splice of the bat finishes
above the
lowest level of the shoulder of the bat; the splice of the bat is incorporated
entirely
within the handle and optionally additionally in the area above the lowest
point of the
shoulders of the bat; the widest diameter of the bat in which the splice is
incorporated
is no greater than 6.5 cm; the percentage of the bat that has a width of less
than 10.8
cm is between 50% and 70%; the length of the bat is between 83 cm and 90 cm
long;
and the blade is between 30% and 50% of the length of the whole bat.
In a particularly preferred embodiment of the present invention, there is
provided a
cricket sports bat comprising an elongate handle and a blade, the blade
comprising a
front playing face, an opposing rear surface, sides extending between the
front face
and rear surface, a toe and a pair of shoulders extending one each side of the
handle/blade to the sides, characterized in that the ratio of the length of
the blade to
the width of the blade is in the range of 3.75:1-3.68:1; the largest width of
the bat is in
the range of 10.6 cm-10.8 cm; the length of the blade is in the range of 39 cm
to 43 cm
long; the splice of the bat is incorporated entirely within the handle and
optionally
additionally in the area above the lowest point of the shoulders of the bat;
the widest
diameter of the bat in which the splice is incorporated is no greater than 6
cm; the part
of the bat which incorporates the splice has an average diameter of between
3.5 cm
and 4.5 cm; the length of the bat is between 84 and 86 cm long; and the blade
is
between 43 % and 47.5 % of the bat length.
Preferably, the bat is shaped such that it is symmetrical about the central
plane.
Preferably the length of the front playing surface is reduced by no more than
25%-35%
with an average of 28.4% from the top portion of the blade below the handle
and
shoulders on both sides of a standard bat, which is the useless part of the
blade from
an attacking shot perspective (As compared to a standard senior cricket bat).
All
effective attacking shots are played in the remaining 65%-75% with an average
71.6%
of the blade (As compared to a standard senior cricket bat). Further weight
loss
maybe achieved by the removal of the shoulders though the weight maybe
transferred
to the sweet spot. The reduced blade length will allow it to travel faster
through the air.
In a preferred embodiment the playing area of blade may have a maximum length
of
28 cm to 40 cm and a maximum width of 10.8 cm. A typical standard senior
cricket
bat has a blade with a total length of 55.5 cm and a width of 10.8 cm.
The present invention provides a cricket sports bat with a number of
advantages over
standard cricket bats (standard cricket bat being not more than 96.5 cm in
length and
10.8 cm at its widest part, and having a blade with a total length of between
54 and 57
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cm, usually about 55.5 cm). For example, the effective additional length of
the handle
and shorter length of blade provides for a more flexible bat. This allows
greater power
to be imparted to the ball. Also, the bat having a relatively short blade
(compared to a
standard bat) is less wind resistant. This allow a substantially increased bat
speed to
be effected while using the same or even less power than used to impart the
same bat
speed to a standard bat. As mentioned above, because a greater volume of wood
can
be incorporated into the shorter blade without increasing the weight of the
bat
compared to an average standard bat, substantially more power can be achieved
over
a greater surface area of the face of the blade.
In another embodiment the section of the side and/or rear surface may further
comprise depressions to remove additional weight from that region of the
blade.
Preferably at least part or all the mass of the blade that would have been
located where
in the top 25%-35% of the old styled blades is added to the rear surface in
the region of
or adjacent the sweet spot. Preferably at least part of that removed mass is
added to
the back surface adjacent the normal sweet spot region so as to extend the
area of the
sweet spot. This redistributing of weight in the blade not only enables the
sweet spot
to be enlarged but also enables the centre of gravity of the bat to be
changed. This
enables the "lift" of the bat to be changed, without adding any extra weight
to the bat
and without removing weight from the region of the blade along the central
plane. It
may also provide the bat with greater stability by removing weight from the
top of the
blade and locating it closer to the central plane thus changing the rotational
pitch of the
bat. Preferably the removed mass taken from where the location of the removed
mass
and moved to the sweet spot is between 200 grammes and 500 grammes in a
cricket
bat. The standard weight of a cricket bat varies from 1.049kg to 1.475kg, with
the
average being about 1.134kg. The amount of weight removed from the blade is
preferably from 20% to 35% of the total weight of the bat.
In one preferred embodiment, at least part of the mass from of blade where any
depressions are located is not included in the bat and the remaining weight is
distributed such that a bat is produced which is lighter than an equivalent
traditional
bat but with at least as good hitting qualities. More preferably only part of
the removed
weight is added to the sweet spot so that a lighter bat with an extended sweet
spot is
produced that has at least as good hitting qualities as the equivalent heavier
traditional
bat.
Additionally, the back surface of the blade may include depressions and/or
other
shape changes to enable weight to be redistributed within the bat. Preferably,
the back
surface is chamfered in the region of handle and/or in the region of the
shoulders,
and/or in the region of the toe. Weight and mass from one or both of these
chamfered
sections or other depressions in the rear surface may be added to the back
face at or
CA 02725327 2010-11-23
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adjacent the sweet spot or elsewhere to balance the bat. Also the non
traditional
shortened splice will also increase the size of the sweet spot.
The bat is preferably made of wood or a combination of different woods.
Current bats
are made of willow but any suitable wood or combination of woods may be used.
Further, metals, aluminum, plastics, glass fibre, carbon fibre and other
composite
materials and any other suitable materials and combinations of materials may
also be
used in the construction of the bat or parts thereof. The bat handle is
preferably made
of cane, wood, twine, rubber and fiber glass. As a proportion of the total
volume of the
handle, materials other than cane, wood or twine is restricted to one-tenth.
Such
materials must not project more than 3.25 in/8.26 cm into the lower portion of
the
handle.
Binding and covering of handle: The permitted continuation beyond the junction
of the
upper and lower portions of the handle is restricted to a maximum, measured
along the
length of the handle, 2.5 in. /6.35 cm for the twine binding, 2.75 in. /6.99
cm for the
covering grip. The handle length shall preferably not exceed 50.18 cm or 52%
of the
overall bat length, the handle width shall preferably not exceed 5 cm. The
splice (lower
handle portion) may enter the playing area blade 0 cm to 14 cm and may be part
of
the playing area, but preferably not. Ideally the splice enters the front
playing area 0
cm to 3 cm, thereby further enlarging the sweet spot.
Brief Description of the Drawings and Photographs
In Fig. 1 there is shown a plan view of a Woodworm bat according to the prior
art
design.
In Fig. 2 there is shown a plan view of UK Patent 1391120 bat according to the
prior art
design.
In Fig. 3 there is shown a plan view of a Woodworm bat according to the prior
art
design.
In Fig. 4 there is shown a plan view of a Slazenger WG bat according to the
prior art
design
In Fig. 5 there is shown a plan view of a front playing face of the bat
according to one
embodiment of the invention, where A is the handle width of preferably 1 cm to
5 cm,
B is the handle length of 10 cm to 50.18 cm, C is the shoulder width of
preferably 1.5
cm to 4 cm and D is the total length preferably from 30 cm to 96.5 cm.
In Fig. 5A there is shown a plan view of a front playing face of a preferred
bat shape
according to the present invention, where A is the handle width, B is the
handle length,
C is the shoulder width, D is the total length of the bat, E is the blade
length, F is the
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distance from the handle to the point at which the shoulder meets the side of
the blade.
The bat comprises a blade 1, a handle 2, joined to the blade by a splice 3.
One of the
shoulders of the bat is labeled 7 and bridges the distance between the handle
and the
edge of the shoulder 4 (the point at which the shoulder joins the blade and
the lowest
point of the shoulder). The toe of the bat is shown as 5. The side of the bat
is shown
as 8. The end of the splice is shown as 6. It can be seen that the splice 3
does not
enter the blade area. The end of the splice 6 is located above the lowest
point of the
shoulders 4. The handle is usually wrapped in twine (string) and covered with
a rubber
or plastic grip (neither shown labelled).
In Fig. 6 there is shown a side plan view of the bat shown in Fig. 5, where A
is the
handle width of preferably 1 cm to 5 cm, B is the handle length preferably of
10 cm to
50.18 cm, C is the edge width preferably of 1.5 cm to 6 cm and D is the total
width
preferably from 6 cm to 10.8 cm.
In Fig. 7 there is shown a plan view of a front handle and splice of the bat
shown in
Fig.5. where A is the handle width preferably of 1 cm to 5 cm, B is the handle
length of
preferably 10 cm to 50.18 cm, C is the splice length preferably of 1.5 cm to
14 cm.
In Fig. 8 there is shown a plan views of a front playing face of the bat
according to
other embodiments of the invention with different splice configurations.
Configurations
P1 d and P3 are particularly preferred configurations.
In Fig. 9 there is shown a plan views of a front playing face and side of the
bat
according to another embodiment of the invention compared to a standard bat.
In
Fig. 10 (a), (b), (c) and (d) is a photograph of invention prototype with
spliced playing
surface.
In Fig.11 (a), (b), (c) and (d) is a photograph of another invention prototype
with
spliced playing surface.
In Fig.12 (a), (b), (c) and (d) is a photograph of another invention prototype
with
spliced playing surface.
In Fig.13 (a), (b), (c) and (d) is a photograph of another invention prototype
with a non-
spliced playing surface.
In Fig.14 (a), (b), (c) and (d) is a photograph of another invention prototype
with a non-
spliced playing surface.
In Figs. 15, 16 and 17 are photographs of the invention prototypes compared at
different angles with different splice configurations in the playing area of
the bat.
In Figs. 18a, 18b and 18c is a preferred embodiment of the present invention.
Figures
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18a 1.1 and 1.2 are perspective view of the cricket bat. Figures 18b 1.3 and
1.4 are
front and back views of the bat respectively. These clearly show that the
splice it
incorporated mainly in the handle of the bat, and non of the splice enters the
playing
surface of the bat. Figures 18c 1.5, 1.6 and 1.7 are side, top and bottom view
of the
cricket bat.
Figure 19: The 4 positions tested for the Cricket bat of the present
invention.
Figure 20: The 5 positions tested for the comparator bat.
Figure 21: Load always mid-span.
Figure 22: Typical bending stiffness experiment result (load in kN against
deflection in
mm).
Figure 23: Experimental set-up.
Figure 24: A typical FRF for one position on a bat of the present invention.
Figure 25: Pendulum arrangement for Moment of Inertia measurements.
Figure 26: Bending stiffness for Bat 1 of the present invention.
Figure 27: Bending stiffness for Bat 2 of the present invention.
Figure 28: Bending stiffness for Bat 3 of the present invention.
Figure 29: Bending stiffness for Prior art bat.
Figure 30: Vibration energy along first lateral edge of the bats. In this and
the following
figures, "Mongoose" refers to a bat of the present invention and "Woodworm"
refers to
a bat of the prior art.
Figure 31: Vibration energy along a line central to the bats.
Figure 32: Vibration energy along a second line central to the bats.
Figure 33: Vibration energy along second lateral edge of the bats.
The following numbered embodiments represent particularly preferred
embodiments of
the present invention.
1. A cricket sports bat comprising a handle and a truncate blade having a
larger hitting
sweet spot, the blade comprising a front (handle non-splice or handle spliced)
playing
face the majority of which is substantially planar across its face, an
opposing rear
surface and sides extending between the front face and rear surface, toe and a
pair of
shoulders extending one each side of the blade/handle to the sides,
characterized in
that the front and back upper playing surface has been reduced in size by the
majority
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removal of the blade along and below the handle and shoulders on both sides as
compared to a standard bat.
2. A sports bat according to embodiment 1 further comprising a central plane
extending longitudinally through the handle and blade, the plane of which is
perpendicular to the front playing surface at the point where it intersects
said surface,
wherein there is provided upper playing surface has been reduced above the
shoulders as compared to a standard bat, such that the bat is symmetrically
shaped
about the central plane.
3. A sports bat according to embodiment 1 wherein there is both sides of the
upper
blade comprises of a reduced area above the shoulders as compared to a
standard
bat.
4. A sports bat according to embodiment 3 wherein the reduced upper blade area
above the shoulders on the blade side and the located furthest and closest
away from
the legs of a player when he is holding it in the normal stroke playing
position.
5. A sports bat according to any one of embodiments 1 to 4 wherein the removed
parts of the blade are located in the section of the blade located within a
25%-35% of
the overall length of the blade, closest to the handle above the shoulders.
6. A sports bat according to any one of embodiments 1 to 5 wherein the width
of the
front and back upper playing surface above the shoulders is reduced by no more
than
30%-50%.
7. A sports bat according to any one of embodiments 1 to 6 wherein the length
of each
side of the upper blade that is removed above the shoulders is from 25 to 35%
of the
length of the blade.
8. A sports bat according to any one of embodiments 1 to 7 wherein the section
of the
side and/or rear surface adjacent further comprises depressions.
9. A sports bat according to any one of embodiments 1 to 8 wherein the amount
of
weight removed from the location of the upper part of the blade above the
shoulders
and/or depressions are from 13% to 40% of the total weight of the bat.
10. A sports bat according to any one of embodiments 1 to 9 wherein at least
part of
the mass removed from the blade and any depressions are located is added to
the rear
surface in the region of or adjacent the sweet spot.
11. A sports bat according to embodiment 10 wherein distributing of at least
part of the
removed mass provides an enlarged sweet spot to be and/or changes the centre
of
gravity.
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12. A sports bat according to embodiment 10 or embodiment 11 wherein the mass
is
used to form a mound about the sweet spot symmetrical about the central plane.
13. A sports bat according to any one of embodiments 10 to 12 wherein the
removed
mass from the upper portion of the blade above the shoulder and any
depressions is
traditional bat but has at least as good hitting qualities.
14. A sports bat according to any one of embodiments 10 to 12 wherein only
part of
the removed weight is added to the sweet spot so that a lighter bat with an
extended
sweet spot is produced that has at least as good hitting qualities as the
equivalent
heavier traditional bat.
15. A sports bat according to any one of embodiments 1 to 14 wherein removed
upper
portions of the blade above the shoulders and re-distribution of weight will
give greater
blade speed.
16. A sports bat according to any one of embodiments 1 to 15 wherein the
effect of an
elongate handle by the removal of the upper portions of the blade above the
shoulders
as compared to a standard bat and redistribution of weight will give greater
blade
speed.
17. A sports bat according to any one of embodiments 1 to 16 and a standard
bat
wherein the effect of not having the majority of the handle splice in the
front playing
area will increase and maximize the sweet spot to the full area of the front
playing
surface.
18. A sports bat according to any one of embodiments 1 to 17 wherein the bat
blade
and handle including the splice can be of any colour natural or man made.
Data:
1. Introduction
This section describes a set of experiments in order to assess the performance
properties of two types of cricket bat. This forms part of a larger study in
which multiple
bat types will be assessed. The aim of this study is to compare performance
characteristics of the Cricket bat of the present invention and prior art
cricket bats.
The cricket bat exhibits important elastic properties, since it is not
completely rigid,
during swing and impact (Noble, 1998). Studies suggest that the vibrational
behaviour
of a bat approximates that of a uniform beam (Noble, 1998; Brooks et al, 2006;
Jaramillo et al, 2003). Noble (1998) represented the baseball bat as a
uniformed rod,
clamped at the point of contact with the hands and defined for various
amplitudes of
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vibrational modes, the approximate length and node locations. Nodal point
positions
are quite important when assessing bat performance since vibrational modes are
not
excited when the ball strikes the bat at nodes of given modes (Noble, 1998).
The boundary conditions have a significant effect on the bat's vibrational
response and
it is important for the bat to impact excitation when it is under boundary
conditions
analogous of those used in real games (Brooks et al, 2006). Brooks et al,
(2006)
determined the frequencies and mode shapes for the first four modes of
vibrations for
three different boundary conditions; the `freely suspended', the `clamped
handle' and
the `hand held' condition. The `freely suspended' condition uses strings to
support the
bat in two positions at the end of the handle and at the end of the blade so
that the bat
is free to vibrate (Brooks et al, 2006; Jaramillo et al, 2003). The results of
the modal
analysis showed that during impact the vibrational response of a 'freely
suspended' bat
corresponds to that of a `hand held' bat (Noble, 1998; Brooks et al, 2006).
Noble
(1998), defined that for a `freely suspended' rod the number of nodes for each
successively higher mode increases by one at each step. In the same study the
node
locations and the frequency of the fundamental and first harmonic modes were
measured for baseball bats. Finally, modal testing was also employed by Gutaj
(2004)
who excited a `freely suspended' bat in order to determine its elastic
properties.
Experimental modal analysis has enabled researchers to define each bat's
`sweet spot'
as the region of low vibrational energy absorption, by changing the blade's
profile the
`sweet spot' can move (Brooks et al, 2006). Studies have also demonstrated the
importance of stiffness and mass distribution to the bat's vibrational
properties (Shaw,
2004; Brooks et al, 2006; Jaramillo et al, 2003; Smith, 2001). The higher
elastic modes
have been found to play significant part in restoring 50% of the loss in ball
velocity, a
degradation usually associated with the bat's stiffness (Noble, 1998).
Therefore, in this study, both bat stiffness (bending stiffness) and freely
suspended
vibration analysis will be conducted.
The Moment of Inertia (Mol) of a cricket bat is a measure of it's resistance
to being
swung. As such, this is a direct measure of the `pick up' weight of a bat.
This is
equivalent to the `swing weight' of a tennis racket (Brody, 1986). In
addition, a racket or
bat with a greater Mol imparts greater energy to the ball for the same angular
velocity
and thus will strike the ball further. There are two ways of increasing the
Mol of a bat.
The first is to increase the mass of a bat. The second is the redistribute the
mass of the
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bat further away from the rotational axis. In the light of the different
designs of bat
available that have significantly redistributed mass by reducing blade hitting
area it was
decided to quantify the Mol of the different bats available according to the
method of
Brody (1986).
2. Materials and Methods
2.1 Bending Stiffness
The cricket bats were placed over two supports specifically designed for this
type of
testing. All the bats were loaded up to 4 kN with a constant rate of 5 mm/sec.
All the
bats were tested at four/five different points and for each point the test was
repeated
ten times. These are summarized in Figures 19 and 20.
Bending stiffness was calculated as below. The test configuration is shown is
Figure 21.
Bending Stiffness: a= E = I = P L3
48=W
(L = 176 mm in all cases)
Bending stiffness was calculated from the slope of the curve between 2100 and
3800
kN (example curve in Figure 22).
2.2 Vibration Analysis
The cricket bats were excited with the impulse hammer technique. As shown in
Figure
23 the experimental setup is based on the use of an impulse hammer to excite
the bat
over a range of frequencies and an accelerometer. The frequency range was set
at 0-
1200 Hz and the accelerometer was attached on the back of the blade near the
toe
region using a thin layer of wax (Brooks et al, 2006). This position was
chosen as it did
not correspond to any of the nodes of vibration (Brooks et al, 2006; Gutaj
2004). Each
of the cricket bats tested had marked out a series of equally spaced impact
points
along the blade's hitting surface covering the length and width of the blade
from toe to
neck. During testing each of the points was impacted three times by the hammer
and
the average frequency response was quantified using appropriate software
SignalCalc
ACE (Dynamic signal analyzer) from Data Physics. The Experimental set up is
shown
in Figure 23.
For this work the first three bending modes are included in the
magnitude/energy
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calculations as higher modes are unlikely to be excited and lower modes may
include noise. The Y axis on the Figure 24 is:
X Sz
F N
and the x-axis is the frequency response in Hz.
2.3 Moment of Inertia
In this study, the moment of inertia about an axis through the handle of the
bat was
determined by turning the bat into a physical pendulum (Brody, 1985). The
period of a
physical pendulum is given by the formula:
I
T =2=;c-
mgd
Where I is the moment of inertia of the bat, m is its mass and d is the
distance between
the pivot point and the centre of mass (CoM.).
A 6 mm hole was drilled through the handle of each bat and a rod was inserted
through the hole to form an axis of rotation. A frame was manufactured out of
mild steel
to support the rod so as to allow for the bat to be held in a vertical
position in order to
swing freely. Each bat was displaced from the vertical position through
varying angles
ranging up to 100, so that the small angle approximation:
sina=a(for a<_14)
was valid, and then released. For each initial angle of displacement, 10 full
cycles were
recorded using an electronic timer and the mean period (the time required for
a
pendulum to oscillate through one complete cycle) was determined. The mass of
each
bat was then measured to within 1 g. The position of the CoM was determined by
a
balance experiment. / was determined from the equation below:
I=T2mgd
4.T2
Due to the small variability in mass of bats, the moments of inertia were also
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normalised by scaling linearly to the lowest bat mass.
Figure 7 shows the pendulum arrangement for Moment of Inertia measurements
3. Results
3.1 Bending Stiffness Experiment
Testing and analysis of four bats was completed; three Cricket bats of the
present
invention and one prior art bat. Complete results are presented below in
Figure 26-29.
The Cricket bats of the present invention bending stiffnesses were 0.373 kNm2
with a
standard deviation of 0.017. This demonstrates that the bending stiffnesses
were highly
consistent within and between Cricket bats of the present invention.
The Prior art bat bending stiffness was 0.297 (0.043) kNm2. This is 20% lower
stiffness
than the average Cricket bat of the present invention with a higher
variability than the
Cricket bat of the present invention.
The bending stiffness of the Cricket bat of the present invention bat/handle
interface
was 0.320 (0.02) kNm2 compared to 0.283 kNm2 for the Prior art bat.
3.2 Vibration Analysis
Vibration analysis was completed for two Cricket bats of the present invention
and the
Prior art bat. Frequency data are summarised in Table 1 below.
Bat 2nd mode of 3rd mode of 4th mode of vibration
vibration frequency vibration frequency frequency in Hz
in Hz (SD) in Hz (SD) (SD)
Bat 1 130 (2) 408 (3) 736 (6)
Bat 2 130 (2) 405 (2) 732 (4)
Prior art Bat 142 (2) 467 (4) 789 (4)
Table 1: Frequency of the three main bending modes of vibration
Vibration energy results for all three bats are shown in Figures 30-33. These
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demonstrate that the energy imparted to the batsman through vibrations is
equivalent
for all three bats tested.
3.3 Moment of Inertia
Bat Mass Distance to Moment of Normalised
(kg) CoM (m) Inertia (kgm2) Mol (kgm2)
Bat 1 1.272 0.479 0.3535 0.3390
Bat 2 1.274 0.471 0.3436 0.3290
Bat 3 1.272 0.480 0.3491 0.3348
Average for Bats of the 1.273 0.477 0.3487 0.3343
invention
Prior art bat 1.220 0.461 0.3124 0.3124
Table 2: Moment of Inertia for all four bats tested
The Cricket bats of the present invention have on average an 11.6% higher Mol
than
the Prior art bat. When scaled to an equal weight this is 7.0% higher. The CoM
of both
types of bat are within 3% of one another.
4. Discussion
The Cricket bats of the present invention have a stiffer blade. This is due to
the robust
rectangular cross section that is maintained along the length of the blade and
is
different from the Prior art bat. Compared to a traditional cricket bat
design, the Cricket
bat of the present invention has stiffened up the blade more without
stiffening up the
handle. This is likely to have a performance advantage without compromise of
batsman
comfort.
The Cricket bats of the present invention have vibration frequencies that are
similar to
the Prior art bat. This is likely due to the consistency of materials and
manufacture
methods employed; the bats were all manufactured by the same manufacturer. The
vibration energies were equivalent between the two bat designs up to 26 cm
from the
toe and demonstrated that they had equivalent `sweet spots'. When the ball
strikes
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above this point, the traditional design has a lower vibrational energy than
the Cricket
bat of the present invention. This is clearly due to the longer blade.
The most significant performance difference between the bat designs is that
the Cricket
bat of the present invention has a higher Mol for the same mass of bat. This
means that
holding both bats vertically will `feel' equivalent, but the bat `pick up'
will feel heavier for
the Cricket bat of the present invention. Conversely, swinging the bat with
the aid of
gravity and providing a rotational pivot about the hands will feel lighter for
the Cricket
bat of the present invention due to the dynamics of the bat. This will enable
a higher
striking velocity on the ball. Based on this significant finding, the cricket
bat of the
present invention will strike the ball further. In addition, although not
quantified in this
study, as the surface area of the Cricket bat of the present invention blade
is less than
the Prior art bat, so it will experience less resistance when swung through
air. This
further enhances the blade striking velocity.
5. Conclusions
The Cricket bat of the present invention bat has been designed to redistribute
mass
along a smaller blade. This has resulted in a bat that for the same pick up
height has
the potential to impart more energy to the ball. This is due to an increase in
moment of
inertia. The relative stiffness of the bat and lower air resistance is
predicted to enhance
this effect.
6. Bibliography
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for
measuring moment of inertia and centre of percussion of a baseball or softball
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American Society for Testing Materials (ASTM), (2005), Standard Test Method
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Brody H., (1986), The sweet spot of a baseball bat, Am. J. Physics, 54, 756-
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Brooks R., Mather J.S.B., Knowles S., (2006), The influence of impact
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Drane, P., and Sherwood, J.A., (2004), Characterization of the Effect of
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mass properties and bat velocity, Sports Engineering, 5, 1-8
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