Note: Descriptions are shown in the official language in which they were submitted.
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ROUND OF THE INVENTION
Most games can be played outdoors after dark because they
are played in relatively small areas which can be economically
illuminated. A few examples are football, baseball, tennis,
hockey, track and field and soccer. Golf courses on the other
hand, Wi~l holes averaging 300 to 400 yards in length and covering
large acreage cannot be illuminated for play after dark at a cost
economically sustainable. Play of golf at night has therefore
been limited to pitch and putt courses, driving ranges and
executive type short hole courses.
Attempts have been made to provide golf balls sufficiently
visible in the dark so that limited play of golf might be attempted
on unlighted golf courses. The visibility of such balls, usually
coated with luminous paint, has been so inadequate that they have
not co~e into any appreciable use.
SUMMARY OF THE INVENTION
The golf ball of the present invention serves a dual purpose.
It may be used in the daytime the same as a conventional ball or it
may be illuminated by the insertion . . . . .
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therein of an activated chemiluminescent light 5tick for use
in the dark.
The ball may be of any size and weight for informal play
but in a preferred form it will comply with the rules of the
United States Golf Association as to weight, diameter and
velocity. The ball structure is completely different from all
golf bal~s now commonly in use in that it is made of a
homogeneous translucent plastic by known methods such as for
example cast molding, injection molding or reaction injection
molding. ~he term translucent plastic includes a transparent
plastic. In the preferred form the molds are constructed to
pLoduce a ball not le6s than 1.680 inches in diameter with the
customary dimples covering the surface. The specific gravity of
the plastic of which the ball is made is such that the finished
ball made of this homogeneous material will weigh close to
but not over 1.620 ounces. These two measurements meet the
requirements of the rules. Finally, the velocity factor is not
more than allowed by the rules.
In the preferred form of the invention the translucent ball
is tough, durable and elastic and reacts with wOOa clubs and
irons with substantially the same feel and distance as is
characteristic of conventional golf balls. One plastic of which
the ball may be made is thermoplastic polyurethane whose
composition and essential characteristics will be set forth
hereinafter. This material, while translucent, may be whitish
or colored to meet golfers' preierenoos. ID this w3y, we h3ve
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¦provided a totally new golf ball of exceptional durability,
¦novel appearance and within the rules 50 that it may be used
in daytime competition and also in the dark. The ball does not
go out of round after extensive use, i.8 practically cut proof
and substantially indestructable under normal use.
It should also be noted however that any suitable translucent,
somewhat elastomeric thermoplastic or thermosetting plastic
can be used in the manufacture of the ball, such as for example,
a polypropolene or polycarbonate although the polyure~hanes are
preferred. Slightly foamed plastics may be used to make balls
of lower density. ~ranslucent fillers such as glass microspheres
or Jround glass may be used for special effects.
In a second form of the invention, the translucent ball
while still within the rules as to weight and diameter, is made
¦with greatly reduced resilience so that it will travel a much
shorter distance than the preferred form when hit in the same
manner. This species finds its greatest use on the so-called
executive type short courses.
The balls above described have one added feature which
will further distinguish them from conventional balls. This
Ifeature is a permanent hole extending diametrically through the
¦hall. This hole about 3~16 inch in diameter is unnoticeable
¦¦in ordinary inspection when the ball i5 on the ground. The hole
has no ef~ect on the ball in flight or when putted on the green.
The object of the hole is to make possible the acceptance
therein of a chemiluminescent light stick now commonly available
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in the marketplace, The purpose of the light stick when
activated and placed in the hole is to create a sufficient degree
of illumination of the ball so that it is clearly visible in
the dark, in flight or on thc ground.
Thus the ball of this invention makes two new situations
possible. A player starting late in the afternoon might be
overtaken by darkness befora completing his round. In such
case when using a conventional ball which cannot readily be
seen in the dark, he must stop play. If on the other hand
he is using or has available a ball of the present invention,
he may activate a chemiluminescent light stick, insert it
¦se~urely in the diametrical hole in the translucent ball to
¦produce at once a ball so well illuminated that play can be
!continued to finish the round,
In the second situation, since the effective life of an
activated chemiluminesc~nt light stick used with the ball is
several hours, it becomes possible for a golfer to play a
complete round after dark. With the light from the light
s~ick emanating in all directions through the translucent ball,
the ball is continuously visible in flight and likewise fully
; ` visible on the ground.
¦ The chemiluminescent light stick used with our golf ball
¦is an article of commerce made by the American Cyanamid
Company of Wayne, New Jersey and sold under the trademark
CYALUM~, It i8 approximately 1 7/16 inches long~ 3/16 inch
in diameter and weighs less than 1 gram. Thus the ball, with
or without the light stick in place behaves in play with no
noticeable difference to the player.
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Another important feature of the invention i8 the provision
of means for causing diffusion of the light emitted from the
ball when the liyht stick i8 in operative condition. While it
has been said above that the material of which the ball is made
is translucent in that one cannot see through the ball, the
: material is comple~ely transparent when of limited thickness.
Thus the degree of translucency of the ball is high permitting
a very high percentage of the light stick light to escape from
the ball surface.
The luminosity of the ball is greatly increased through the
inclusion in the ball structure of the previously referred to
dil,lples which are closely spaced over the entire ball surface.
These dimples are in the form of hollow concave spherical
segments and according to the arrangement and size will total
upwards of 360 or more individual dimples. It will be
understood that the number, diameter and depth of the dimples
may be varied as preferred by the ball manufacturer.
Each of the dimples provides means for diffusion of the
light leaving the ball as it passes outward through the entire
spherical area of the dimple. That i5, acting in accord with
j the principles of refraction of light passing from a transparent
~solid to the air, the light will be bent by every portion of the
~ I! dimple's surface area which is not normal to the light beams
; ¦Iflowing thereto from the light stick. Thus the ball, when
stationary, while sufficiently illuminated over its entire
surface so as to be clearly visible in the dark, appears lighted
to a further degree by the diffused light coming from those
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dimples that are positioned to transmit refracted light to the
eyes of the player.
When the light stick i5 more or less at right angles to the
line of vision to the player with the ball stationary, the light
stic~ appears as a glowing internal mass about twice its actual
iameter along a wide equatorial band of dimples. This band of
refracted light is substantially brighter than the other surface
areas of the ball to-the north and south thereof where the
dimples are at such an angle as to be unable to refract the
light toward the viewer eyes. When the ball is in flight and
rotating rapidly, there will always be a large number of dimples
ins~antaneously positioned to transmit to the player light
concentrated by the refractory power of the dimples to give the
ball a brightness that would not be present in the absence of
~the dimples.
The translucency of the ball material combined with the
I dimples provides a light multiplying effect to increase the
illumination of the ball stationary or in flight.
BRIEF DESCRIPTION OF THE D~AWINGS
Fig. 1 is a side elevation of the golf ball with the hole
therethrough in polar axis position.
j Fig. 2 is a plan view o Fig. 1.
Fig. 3 is an enlarged view of a chemiluminescent light
stick suitable for use with the ball.
Fig. 4 is a cross sectional view taken on the line 4-4 of
Fig. I showiDg the light sti7t i= po:ition in the hole.
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¦ Fig. ~ is a cross section of a portion of the ball to
¦enlarged scale showing the refraction of the light by some ofthe surface dimples.
Fig. 6 is an elevation of the ball with the light stick in
horizontal position and showing the width of the band of dimples
that refract light to the viewers eyes.
DESCRIPTlON OF A PREFERRED EMBODIME~T
Referring first to Figs. 1 and 2, there is shown in
~k!vation and plan view the thermoplastic polyurethane golf ball
2 the specific cornposition of which will be detailed below.
The finished ball has over its entire surface the cuStomary
dimples which cause the ball to move along a truer path in
flight. The ball has a continuous diametrically positioned
hole 6 extending therethrough. This hole may be made in the
; ball molding process or it may be drilled through the finished
ball.
The solidified polyurethane forms a hard, tough, resilient
ball having substantially the same playing characteristics as
¦ and greater life than any conventional high quality golf ball.
¦IThat is, this ball when hit by the same player with the same
¦¦club will behave in flight and distance the same as a
conventional ball. The clicking sound produced as this ball is
hit is similar to the sound of the same club hitting a
; conventional ball. Thus a capable golfer could play with this
ball as effectively as with a conventional ball.
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Generally speaking most golfers develop a preference for a
particular brand of conventional ball so it is unlikely that
this ball would at the outset supplant a player's present
favorite. However, many players though not using this ball
regularly in the daytime would not be averse to shifting to
this ball should the occasion arise where illumination would be
helpful or necessary. The probability of loss of this ball in
failing light when illuminated by a light stick is greatly
diminished.
~ he light stick 8 shown enlarged in Fig. 3 is activated by
manually bending it until the vial 10 therein breaks to allow
i:h~: separated chemicals 12 and 14 to mix thereby to give off a
cold luminescence. The light 5tick 8 while a trifle larger in
diameter than the hole 6 can ~e forced by hand into the hole and
centered by pushing it with the end of a golf tee or similar
tool to place each end below the ball surface.
In the preferred case, the light stick is held in place
by friction against the hole wall but it is to be understood
that any other means for keeping the light stick in removable
or permanent position may be used. Since the llght stick has a
limited life, it is preferable that the light stick be
rPmovable so that another activated light stick may be inserted
when illumination of the ball is again needed.
A dead light stick may be removed from the ball by
pushing it with the end of a golf tee far enough to permit the
other end to be gripped by the fingers and pulled out.
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Tests have shown that no matter how many times this ball
made in accordance with the following detailed specif1cation3
is hit with a golf club, the light stick because of its small
mass and large area of frictional engagement or other securing
means will stay unbroken within the hole.
In a second embodiment of the invention, the outward
appearance, weight, diameter and translucency of the ball are
all substantially the same as in the preferred embodiment.
The difference lies in the elasticity of the finished ball
which is a controlling factor in the distance the ball will
travel when hit by a golf club. In this second form, the ball
bas slow recovery from deformation. Thus when the ball is hit
by the face of the golf club, it is flattened at the area of
contact but because of itæ 510w restoration factor, leaves the
club face at a speed only slightly greater than the clubhead
speed. The obvious result is that this second form has a much
shorter flight than the preferred form.
This short flight characteristic however is an advantage
rather than a handicap when the ball is used on short courses.
It enables the player to take his customary full swing with all
clubs without fear of overdriving. Since the ball i8 of
standard size ana weight, the wind is no more a factor than
when playing with a conventional ball.
It will be understood that while both of the above described¦
balls will preferably be made to meet the rules of the United
States Golf Association so that the typical golfer will be
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comfortable in their use and so that they may be used in
competition, the invention of a plastic, translucent golf ball
internally illuminated by a chemiluminescent light stick may
also be used with balls of informal diameters and weights.
The following is an explanation of the material9 and
method used in the manufacture of our translucent ball
including the parameters within which our product must stay to
rody~e the results essential to satisfactory golfing use.
The preferred materia~ of which the ba~1 is made is a
product of the Dow Chemical Company (acquired from Upjohn
Comp,any) although it will be understood that the same material
may be made by others.
Under the Dow specifications the material to be molded into
our ball is a thermoplastic polyurethane known as PELLETHANE
2103 Series polyether. This material must be molded to produce
aAhardness factor (Durometer reading) of between 45E-and 65~r.
Between these hardness limits the light stick when inserted in
the ball will remain unbroken, the faces of wooden golf clubs
will not be cracked and no unusual shock will be transmitted to
the players hands when the ball is in use in normal golfing play.
The specific gravity of the 2103 Series polyether is
¦about 1.13 + which permits a dimpled ball to be molded to a
Idiameter of 1.68 inches with a weight close to but not exceeding
¦1.62 ounces. A ball made to these specifications is within the
¦rules of the ~nited States Golf Association.
A further requirement of the material of which our ball is
m:de is that it sho~ld te-t hen in molded form as follows:
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for 50~ elongation, 1950 PS1+
for 100% elongation, 2600 PS1 +
for 300% elongation, 5000 PS1 +.
It should have an ultimate tensile of 6500 PS1 +.
To produce the ball, the ~older injects the aforesaid material
in liq~lid or pellet form into a correctly sized mold and then s~jects
it to heat and pressure according to known processes. These known
processes can be controlled to create the Shore D hardness required
within the limits of 45 to 65. The known molding processes can further
be controlled to create a ball whose tensile strength meets the
standards aforesaid.
The preferred form of ball which will be used in play on a typical
golf course will be made to have a higher durometer reading of 55
and above but not exceeding 65 on the Shore D Scale. The short range
ball is made of the same material and in the same manner but by
varying the heat, pressure and time factors according to knowledge
in the plastic molding art, the Shore D hardness factor will be held
on the lower side between 45 and 55. This will result in the production
of the short range ball in which the restoration factor is relatively
slow. Referring now to Fig. 5 which is a partial cross section of
ball 2 to enlarged scale with the light stick 8 in end on position,
the refraction of light caused by the dimples is illustrated. The
light emitted from three positions in the light stick, namely a, b
and c will be considered.
The rays from position a flowing to dimple 20 behave as follows:
Ray al is bent to the right as at a2. Ray a3 being normal -to the
dimple surface flows straight on as at a4. Ray a5 is bent to the
left as at a6.
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Similarly the rays from the center b of the light stick
passing through dimple 22 follow the paths bl, b2 b3, b4; and
bS, b6. Those rays passing through dimple 24 are indicated at
b7, b8; b9, blO; and bll, bl2. Those ray5 from position c
flowing through dimple 26 follow paths cl, c2; c3, c4; and c5, c6.
From the foregoing it can he seeD that rays a6, b6, b8 and
c2 converge to focus on the players eye~, giving the appearance
to the player that the light stick has a diameter s~ual to the
distance from dimple 20 to dimple 26, a distance about twice the
actual diaméter of light stick ~. The position of the dimples 28
and 30 and those beyond is such that while they also refract
light, they cannot bend the rays enough to reach the players
eyes.
Thus the maximum number of dimple3 that can direct the
refracted light to the players eyes are located in any circum-
ferential band that is parallel to the light stick. This is
illustrated in Fig. 6. The dimples 20, 22, 24 and 26 and others
on the same latitudes form a circumferential band of dimples
having a width W capable of focusing rays from light stick 8
on the players eyes to greatly increase th~ effective total
illumination of the ball.
j The effect is maximum when the band is in the position of
Fig. 6 and diminishes as the ball is rotated to bring the light
stick into end on position. ~owever in end on position the end
of the light stick is visible giving intense direct light to the
viewer as well as a circ le of refracted light from the dimples
around the end of the light stick. The foregoing specific
details are illustrative only. The extent of the refracted l
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light will vary according to the distribution and curvature of
the dimples.
In summary, the dimples about the spherical surface of the
ball serve a-dual purpose; the conventional well understood
purpose of improving the flight of the ball and a secondary
unobvious purpose of increasing the apparent luminosity of a
transluoent plastic golf ball made in the manner aforesaid and
utilizing as a sourc~ of internal light a chemiluminescent light
stick positioned in a dlametrically extending hole. When the
ball is rapidly rotating in flight, persistance of vision gives
the impression to the player that the entire ball is illuminated
~Iniformly~ differing somewhat from the effect when the ball is
stationary on the ground. In both situation, however, the
illumination is more than adequate for the purpose of playing in
the dark.
It is intended to cover all changes and modifications of
the examples of the invention herein chosen for purposes of the
disclosure which do not constitute departures from the spirit and
the scope of the invention.
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