European Patent Office
@ Publication number:
Office europeen des brevets
EUROPEAN
®
©
0 1 7 0 7 8 2
A1
" 1
PATENT A P P L I C A T I O N
®
Application number: 85104619.3
Int. CI.*: A 63 B 39/00, A 63 B 4 1 / 0 0
@ Date of filing: 17.04.85
@ Priority: 06.08.84 US 638110
©
@ Applicant: Wilson Sporting Goods Company, 2233 West
Street, River Grove Illinois 60171 (US)
@ Inventor: Claire, Brian, 802 East Cherry Lane, Arlington
Heights Illinois 60004 (US)
Date of publication of application: 12.02.86
Bulletin 86/7
@ Representative: Patentanwalte Griinecker, Dr.
Kinkeldey, Dr. Stockmair, Dr. Schumann, Jakob, Dr.
Bezold, Meister, Hilgers, Dr. Meyer-Plath,
Maximilianstrasse 58, D-8000 Miinchen 22 (DE)
@ Designated Contracting States : DE FR SE
© A tennis ball has a diameter about 5% to about 13%
greater than the diameter of a standard tennis ball. The ball
has about the same weight, and the thickness of the core of
the ball is less than that of a standard ball. The rebound and
coefficient of restitution of the ball are equal to or better than
the rebound and coefficient of restitution of a standard ball.
ACTORUM AG
Background
This
invention
standard
a tennis
to
particularly,
tennis
of
has
in
participants
of
decrease
or
low
level
tial
level
time
the
the
playing
ball
of
the
the
rallies
and
a more
resulted
from
compared
to
popular,
and
in
in
it
is
air
for
the
decades.
since
that
in
the
the
or
some
people
achieve
that
level
the
perceived
that
and
and
is
sport
real
reach
to
number
players
feel
Many p e o p l e
the
time.
tennis
or
sport
However,
and
1970's,
why many
required
believed
tennis
rebound
high
been
a substan-
maintain
who do not
simply
tennis
balls,
ball.
The
height.
impact
racket.
speeds,
make
to
the
a
have
stop
introduced
This
ball
was
described
tennis
ball
which
game
of
tennis.
and
this
heavy
balls,
have
this
However,
thereby
was
and
because
the
which
on
the
typically
from
the
pressureless
this
ball
resulting
still
in
longer
play
restitution
never
dead
in
slower
of
a slower
as
ball
suffered
Tretorn
The
tennis
a tennis
resulted
coefficient
However,
of
game
Spalding
that
felt
made
1976
pressure
ball.
therefore
Australian
on the
a
the
about
enjoyable
a standard
standard
feel
to
have
Pressureless
at
than
declined
tennis,
a standard
lower
and
ness
is
"Australian."
than
improved
slower
participation
of
time
attempts
ball
the
plays
sport
player.
commitment
playing
as
more
reasons
their
example,
called
than
and,
game.
For
liveliness
primary
skill
of
Some
easier.
balls,
during
has
sport
playing
the
or
a popular
difficulty
skill
of
amount
certain
the
the
perceived
of
tennis
which
peaked
discontinue
or
real
been
tennis
of
popularity
One
ball
to
ball.
Tennis
the
relates
became
ball
lacked
racket.
play
same
ball,
lacks
a heavy,
slower
drawbacks
has
livelidead
of
Summary
This
a standard
than
slower
invention
a standard
ball.
11% l a r g e r
than
moves
a greater
The
more
Since
when
hit
ball
is
also
easier
error,
requires
is
new b a l l
reach
forgiving,
Even
though
the
new b a l l
liv.
ness
more
about
is
provides
when
more
has
a standard
hit
with
Accordfor
margin
rallies
longer
ball
height.
player.
provides
about
and
a greater
the
than
the
than
slower
at
by
3% to
ball
inbounds
plays
lively
that
so
a standard
net
which
than
ball.
same
the
feels
light
The
illustrative
measured
as
it
the
and
is
is
the
core
lively
is
the
will
be
explained
in
has
a standard
The
of
ball,
ball
there-
racket.
of
shown
new b a l l
coefficient
thinner.
Description
embodiment
and
than
larger
the
on
the
slower,
rebound
by
ball
because
invention
Drawing
the
in
with
conjunction
accompanying
an
drawing,
-1 is
Fig.
ball
formed
sized
tennis
angle
and v e l o c i t y ;
balls
Figs.
sized
an
in
2 is
Fig.
various
to
and
Although
tennis
the
over
is
ball
fall
to
ball
is
new b a l l
skill,
restitution.
which
than
likely
more
ball
a standard
less
a standard
weighs
the
the
or
more
which
yet
slowly
force
the
in
of
is
ingly,
fore
diameter
of
tennis
a new
ball
new b a l l
slower
increased
provides
diameter
air
Invention
tennis
visibility.
the
ball,
the
the
through
increased
The
the
illustration,
accordance
an
3 and
tennis
with
illustration
which
are
4 are
balls
hit
partially
the
of
from
illustrations
which
are
hit
away
of
a
invention;
the
the
broken
flight
paths
baseline
at
similar
at
lower
to
of
various
the
same
Fig.
2 of
velocities;
5 is
Fig.
the
6 and
Figs.
of
7 are
tennis
sized
various
of
rubber
is
core
other
or
the
core
standard
light
per
in
is
0.094
core.
felt.
inch,
and
The
felt
of
the
The
be
of
a
from
for
of
inch
of
14 o u n c e s
yard
thickness
to
The
thickness
is
square
conform
12.
formed
is
felt
0.120
of
thickness
12
per
formed
will
as
and
and
about
to
5
velocities.
cover
but,
cover
22 o u n c e s
compared
a felt
diameter
the
used.
at
Fig.
11
a core
manner,
diameter
conventionally
to
lower
at
of
the
to
baseline
Embodiment
The w e i g h t
compared
the
similar
hit
are
material
than
of
paths
and
comprised
hereinafter,
woven
is
which
conventional
ball
yard
which
about
detail
tennis
square
the
flight
from
angles;
10 is
different
are
weight
felt
in
the
hit
are
Specific
elastomeric
molded
explained
ball
of
illustrations
balls
Description
A tennis
which
different
but
velocity
same
balls
tennis
sized
various
illustration
an
the
for
woven
cover
a standard
ball.
tennis
Standard
cations
and
of
the
United
balls
Tennis
States
the
following
Association
for
specifi-
size,
weight,
rebound:
"The
ball
and
shall
be
any
seams
they
be more
than
two
and more
two
and
The
ball
(135cm)
shall
white
than
than
or
shall
be
and
in
If
color.
stitchless.
The
there
ball
(6.35cm)
and
five-eighths
inches
(6.67cm)
in
two
ounces
have
less
(56.7
(58.5
ounces
a bound
than
and
grams)
of
58 i n c h e s
more
grams)
than
(147cm)
less
diameter,
less
in
53
are
shall
inches
and
one-sixteenth
shall
yellow
surface
outer
half
two
and
a uniform
have
than
weight.
inches
when dropped
inches
100
have
a forward
of
inch
(.56cm)
an
and
of
inch
an
(1.08cm)
mation
individual
than
.030
tests
for
about
in
the
of
and
felt
of
feels
a standard
invention
than
of
than
heavy
and
ball
of
standard:
the
core.
on
balls
and
which
three
of
the
even
defor-
ball
differ
by m o r e
case.
All
be
diameter
diameter
ball
a standard
good
the
at
balls
However,
better
tennis
had
and
weight
balls
unsatisfactory
balls
formed
rebound
balls.
and
liveliness
standard
of
in
and
My b a l l
there-
racket.
compares
balls
of
Heretofore,
standard
the
two
outside
the
kept
racket.
than
inch
an
an o u t s i d e
has
than
tennis
have
chart
foregoing
also
is
.350
regulations."
than
ball
on the
lively
each
surprisingly
standard
my i n v e n t i o n
tennis
and
the
restitution
light
The
have
thickness
slower
coefficient
larger
weight
the
with
of
will
which
slower
play
of
deformation shall
11% l a r g e r
will
ball
and
a ball
about
shall
in
than
The
axes
with'I.L.T.F.
that
ball
larger
accordance
fore
found
three
(.08cm)
size
bound,
.425
.220
inch
an
more
averages
readings
inch
an
the
than
of
load.
kg)
along
accordance
tennis
if
of
3% to
played
rebound
be
no two
by r e d u c i n g
which
shall
and
a standard
rebound
(8.165
readings
I have
the
lbs.
figures
of
than
less
and
The'ball
more
.290
than
deformation
individual
made
that
18
at
less
and
(.89cm)
of
deformation
a return
base.
a concrete
upon
shall
(.74cm)
between
(254cm)
the
formed
are
about
physical
in
characteristics
accordance
with
about
15%
1% and
my
coefficient
The
balls
was
measured
The
restitution
as
is
not
and
increase
the
from
in
size.
standard
the
4.6%
ball
ball
restitution
the
speed
the
optimum
The
change
to
to
the
the
4.6%
increased.
increase
in
COR at
is
foregoing
speeds:
better
However,
coefficient
the
increase
about
a 4.6%
is
obtained
at
70
feet
second
ball
larger
15% b a l l
impact
exhibited
surprisingly
impact
the
of
(COR)
various
at
compared
balls
larger
of
linear,
and
of
only
is
per
+0.45,
+0.18.
but
the
from
change
observed
The
believed
thinner
of
energy,
since
they
walls
of
of
size
is
factors:
the
balls
larger
less
experience
ball
strain
may d i s s i p a t e
for
a given
amount
bending.
2.
becomes
As a b a l l
like
more
of
Air,
and
rate,
ther
thus
The d e f l e c t i o n
heavier
size.
4.6%
feel
The
ball
was
various
at
the
different
the
difficult
the
This
relates
is
from
also
which
from
the
balls
less
4.6%
not
the
are
was:
and
related
linearly
to
of
launched
deflection
playability
ball
to
lower.
standard
simulation
shown
the
that
may be
to
been
has
means
spring.
rubber.
than
impact
various
a computer
same v e l o c i t y
launches
of
it
walls,
a rubber
effect
damping
deflection
balls
is
like
dissipation,
of
and
2 is
launches
less
increases,
+0.35
sized
and
balls.
which
in
change
Fig.
of
it
as
thinner
duration
energy
Defelction,
with
less
larger
the
larger
spring
much
time
The
for
greater
gets
an a i r
has
course,
3.
be
COR w i t h
a number
by
The
1.
less
caused
be
to
of
increase
ball
the
the
to
15% b a l l
flight
by a t e n n i s
to
the
was
+0.57.
paths
ball
cannon
and
launch
angle.
Controlled
data
on a c t u a l
to
obtain
because
the
ball
cannon
sized
balls
slightly
tennis
differently
and
launches
of
the
with
launch
size
of
at
an
line
be
seen
that
as
are
more
likely
the
and
speed
second
per
5 is
same
the
sized
they
can
and
inbounds.
ball
hit
be
Thus,
feet
the
is
conditions
ment
that
than
balls
exhibit
standard
than
is
of
117
fall
Fig.
from
feet
second
per
the
on
other
2 is
5.30°.
not
travel
do
they
launched
However,
3 is
96
feet
per
second
and
speed
one
basewill
It
far
as
baseline.
the
2.
in
angle
It
which
the
and
4 is
Fig.
net
at
a greater
margin
c'
The
launch
speed
9.2°,
feet
76
66
testing
was
used
which
were
significantly
A ball
ball,
in
feet
tennis
by
because
extent
the
on
larger
different
which
and
the
than
playing
was
4.6%
players
the
players
"feel"
and
The
hit
larger,
still
land
size
feet
the
of
the
per
second.
launch
speed
acceptable
playing
of
tennis
equip-
"perceived"
testing
ball
was
performance
indicated
did
characteristics
that
range
actual
a standard
felt
to
under
play
larger
the
respectively.
acceptability
performance.
1.2%
5 but
determine
to
96
5 was
at
get
the
as
second,
ball
and
of
paths
balls
height
Fig.
per
the
the
as
Fig.
to
flight
*'ne b a s e l i n e
increases
similar
Testing
that
error
and
the
enable
seen
the
a large
will
be
the
of
from
will
on p r e d i c t e d
a standard
launched
are
an a n g l e
important
ball.
simulation
second
to
depends
rather
at
ball.
larger
actual
an
Fig.
7 are
per
Play
of
by
to
6 and
Figs.
76
the
similar
a computer
over
increases.
was
larger,
launch
baseline.
other
ball
to
in
angle
Fig.
which
balls
velocity
the
16.9°.
and
Fig.
various
in
ball
inside
4 are
the
cf
However,
verified
was
tennis
the
get
fall
to
etc.
a velocity
launch
balls
angle
and
respectively,
at
enable
3 and
Figs.
launch
court
The
away.
because
ball.
standard
will
which
angle
78 f e e t
and
of
a tennis
wind,
spin,
simulation
2 the
In F i g .
baseline
of
computer
each
and
inconsistently
variables
uncontrollable
accuracy
ball
sized
a particular
than
noticeably
they
not
were
a
slower
more
and
accurate
set
rallies
that
ball,
for
up
able
were
the
standard
ball.
ball,
standard
hit
ball
slow
too
the
and
with
more
the
M is
where
increases,
the
when
inertia
mass
the
moment
is
a standard
the
11.2%
4.6%
tion
the
the
R is
of
to
of
ball.
a
some
15% l a r g e r
that
curved
spin
ball.
ball,
and
While
in
the
was
the
than
not
15% b a l l
is
a
perceived
is
when
excessively
a ball
players.
could
they
The moment
inertia
the
the
outside
15% l a r g e r
the
proportional
of
inertia
I of
balls
within
the
As the
= with
ball
the
curves
radius
of
square
excessively
ball.
are
The
radius.
increases
players
with
4.6%
optimum
able
and
to
obtain
increased
the
range
of
8.0%
balls
were
performance
was
2.6%
accuracy
11.2%
to
superior
obtained
larger
to
with
the
ball.
of
purpose
of
the
details
herein
skilled
the
in
the
the
foregoing
embodiments
specific
the
of
that
of
and
imparted
rallies
longer
than
ball.
to
to
is:
Accordingly,
and
the
Accordingly,
spin
ball
time
than
15% b a l l
Further,
power.
larger
also
were
heavy
was
the
more
larger
felt
players
this
and
to
the
radius.
felt
The
believed
shell
a spherical
ball
satisfactory.
and
had
they
11.2%
which
heavy,
spin
and
a ball
hand,
spin,
of
moment
11.2%
sufficient
by
is
It
to
too
imparted
players
not
that
with
characteristics
8.0%
were
control
more
and
same
the
other
was
ball
affected
which
with
longer,
These
although
On the
as
lasted
by b a l l s
exhibited
hit
to
illustration,
art
invention.
given
specification
of
the
it
will
invention
departing
was
considerably
from
the
spirit
descrip-
forth
set
be u n d e r s t o o d
may be v a r i e d
without
a detailed
that
many
for
of
by t h o s e
and
scope
A tennis
1.
a felt
attached
cover
2.689
ball
The
about
is
The
3.
of
the
is
core
The
4.
of
felt
the
The
5.
the
of
felt
feet
The
tennis
7.
diameter
The
of
the
diameter
of
the
of
0.094
inch.
of
of
is
ball
1 in
about
of
which
the
weight
which
the
thickness
0.118
about
claim
ball
1 in
claim
inch.
0.100
about
to
1 in
which
the
thickness
claim
1 in
which
the
weight
per
square
claim
1 in
the
coefficient
14 o u n c e s
about
is
ball
of
within
tennis
ball
of
The
the
10.
cover
outside
is
ball
0.651
claim
the
of
within
to
54
about
is
A tennis
attached
about
the
tennis
ball
diameter
2.689
within
of
range
of
yard.
which
about
to
0.675
70
at
1 in
which
the
of
about
2.689
1 in
which
the
of
about
2.741
1 in
which
the
range
outside
about
to
claim
the
range
outside
about
to
inches.
diameter
to
the
core,
grams.
of
ball
tennis
ball
The
9.
a felt
the
the
inches.
8.
2.830
the
of
and
core
second.
per
2.830
tennis
6.
of
ball
about
about
of
range
tennis
is
58.5
ball
the
claim
of
about
to
cover
restitution
surface
within
being
ball
tennis
is
cover
elastomeric
an
inches.
tennis
within
outside
ball
the
54
comprising
the
to
2.915
about
to
2.
the
of
diameter
outside
ball
of
2.915
58.5
range
about
ball
the
to
the
ball
inches,
grams,
of
ball
and
about
of
claim
2.741
inches.
comprising
outside
being
the
the
0.118
elastomeric
an
surface
within
weight
thickness
to
outside
about
of
the
of
range
the
of
the
ball
the
0.100
core,
of
and
the
about
being
core
inch.
core
about
being
of
felt
the
felt
is
cover
per
of
0.094
claim
14 o u n c e s
ball
10
:.n which
the
thickness
10
in
the
weight
the
coefficient
inch.
ball of
tennis
the
of
claim
per
ball
of
is
about
ball
of
10
0.651
of
yard.
square
claim
which
in
which
0.675
about
to
at
70
feet
second.
14.
diameter
of
2.830
inches
about
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