U.S. patent number 3,782,730 [Application Number 05/204,109] was granted by the patent office on 1974-01-01 for golf ball.
This patent grant is currently assigned to Euronics Limited. Invention is credited to Stephen Alexander Horchler.
United States Patent |
3,782,730 |
Horchler |
January 1, 1974 |
GOLF BALL
Abstract
This invention relates to an electronic golf ball comprising a
central resilient sphere, a mass of elastic material surrounding
the sphere and an outer casing, the central sphere including an
electric squegging oscillator circuit, a battery therefor and a
transmitting coil, all enclosed in a spherical mass of a set resin
which forms a solid core, the spherical mass being located with
close fit in a hollow spherical cavity formed in the central
resilient sphere. The battery is a mercury cell located within the
transmitting coil, as are the other components of the squegging
oscillator circuit. The electrical circuit may include components
which permit the oscillator to be turned on and off when the golf
ball is brought into and then moved out of an A.C. magnetic field
having a predetermined frequency.
Inventors: |
Horchler; Stephen Alexander
(Eskbank, SC) |
Assignee: |
Euronics Limited (Edinburgh,
SC)
|
Family
ID: |
22756661 |
Appl.
No.: |
05/204,109 |
Filed: |
December 2, 1971 |
Current U.S.
Class: |
473/353;
331/108R; 340/323B; 331/117R; 342/385 |
Current CPC
Class: |
A63B
24/0021 (20130101); A63B 43/00 (20130101); A63B
43/008 (20130101); A63B 2024/0053 (20130101); A63B
2225/54 (20130101); A63B 2225/15 (20130101) |
Current International
Class: |
A63B
43/00 (20060101); A63b 043/00 (); A63b
043/06 () |
Field of
Search: |
;273/213,63R,183,199,200 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"Radio-Electronics", June 1956, page 79 273-213.
|
Primary Examiner: Marlo; George J.
Attorney, Agent or Firm: Striker; Michael S.
Claims
What is claimed is:
1. A golf ball comprising an outer spherical casing; an elastic
spherical mass inwardly of said outer spherical casing; and
squegging oscillator means accommodated within said elastic
spherical mass and including an inductor serving as a transmitting
coil, said oscillator means being operative for intermittently
generating an oscillating electromagnetic field for periods of time
which are shorter than the periods of time during which said field
is not generated.
2. A golf ball as defined in claim 1, wherein said squegging
oscillator means comprises a source of electrical energy.
3. A golf ball as defined in claim 2, wherein said source of
electrical energy is a mercury cell.
4. A golf ball as defined in claim 1, and further including a
resilient spherical central core inwardly of said eleastic
spherical mass and having an internal spherical cavity, and further
including a spherical mass of set resin material inwardly of said
central core and tightly fitted within said cavity, said squegging
oscillator means being embedded within said spherical mass of set
resin material.
5. A golf ball as defined in claim 4, in which said transmitting
coil is wound in the form of a cylinder and positioned in said
spherical mass of resin material so that a median plane of said
coil normal to the axis of said coil lies in a diametric plane of
said spherical mass of resin material.
6. A golf ball as defined in claim 5, in which said squegging
oscillator means comprises a mercury cell having a central axis of
symmetry and serving for the supply of electrical energy and
positioned in said spherical mass of resin material and inside said
coil so that the axis of said coil is normal to the axis of said
mercury cell, and wherein said squegging oscillator means includes
a plurality of other electrical components located to either side
of said mercury cell and also located within said coil.
7. A golf ball as defined in claim 1, wherein said inductor
constitutes a transmitting coil, and wherein said squegging
oscillator means comprises a npn transistor having an emitter, a
collector and a base, a capacitor connected in parallel to said
transmitting coil to form a parallel LC circuit having a
predetermined resonance frequency, and a battery connected between
an intermediate tap of said coil and said emitter, a parallel
RC-circuit connected to said base, the ends of said parallel
circuits not connected to said transistor being connected together
and the resonant frequency of the RC circuit being a fraction of
said predetermined resonance frequency.
8. A golf ball as defined in claim 1, wherein said squegging
oscillator means includes magnetic-field responsive means operative
for terminating operation of said oscillator means when the golf
ball is brought into and then moved out of an A.C. magnetic
field.
9. A golf ball as defined in claim 1, and wherein said squegging
oscillator means includes magnetic-field-responsive means operative
for terminating operation of said squegging oscillator means when
the golf ball is brought into and then moved out of an A.C.
magnetic field having a predetermined frequency.
Description
This invention relates to a golf ball containing an electric
oscillator circuit which assists in the recovery of golf balls lost
during a game of golf. It is a well known fact that many golf balls
are lost due to the fact that during play the golf ball lands in a
particularly overgrown area of the golf course. The loss can occur
even though the ball may have been visible during its entire flight
and the approximate region of the landing of the ball is known. The
loss of a golf ball not only entails financial loss to the player
it also means that the player is put at a disadvantage as far as
that game is concerned. The present invention reduces the
occurrence of lost golf balls and players employing golf balls
which can be recovered are at an advantage both financially and by
not losing unnecessary points over lost balls.
According to one aspect of the invention of golf ball comprises a
central resilient sphere, a mass of elastic material surrounding
the sphere and an outer casing, in which the sphere includes an
electric oscillator circuit and a battery therefor, and is
characterized in that the oscillator circuit, a transmitting coil
and the battery are enclosed in a spherical mass of a set resin to
form a solid core, the spherical mass being located with close fit
in a hollow spherical cavity formed in the central resilient
sphere.
Conveniently the oscillator circuit is tuned to a particular
frequency and generates an induction field at that frequency, the
oscillatory circuit squegging so that its output comprises bursts
of oscillation at the desired frequency interspersed by longer
periods of non-oscillation. The duty ratio (i.e. the ratio between
the periods of non-oscillation (off periods) and the periods of
oscillation (on periods)) can be chosen at will, but is preferably
within the range 100:1 to 1,000:1. The bursts of oscillation can be
kept stable and the repetition of these bursts appear in a detector
unit (which may be a simple radio receiver tuned to the frequency
of the oscillator circuit) as a modulation frequency characteristic
of the oscillator circuit employed. By filtering this pulse
repetition frequency the detector unit can respond to different
frequencies making identification of different golf balls
possible.
A suitable frequency range for the oscillator circuit is between 10
kilohertz and 10 megahertz since in this frequency band it is easy
to arrange for there to be a negligible component of radiated
energy.
The "on" period can be as long as a fraction of a second (e.g. 0.1
second) or as short as a few tens of micro-seconds, the only
requirement being that the burst of oscillation should be
sufficiently long to enable it to be reliably detected by the
detector unit. By utilising a large duty ratio, it is possible to
employ an oscillator operating at a carrier frequency as high as 10
megahertz (where a significant proportion of the energy will
produce an induction field from a coil of only a few millimeters in
diameter) and have a mean radiated power output of the order of
microwatts.
Preferably the transmitting coil is wound into a short cylinder and
is positioned in the spherical mass of resin so that a median plane
of the coil normal to the axis of the coil lies in a diametric
plane of the spherical mass. A cylindrical mercury cell makes a
suitable battery and this may be positioned so that the axis of the
coil is normal to the axis of the battery, the other component
parts of the oscillator circuit being disposed on either side of
the battery to lie within the transmitting coil.
The oscillator circuit may operate in the same manner from the time
the circuit is completed until the battery is finally spent (it is
not difficult to arrange for a lifetime of several years using
conventionally available batteries) but a modified oscillator
circuit can be used which can be switched on and off before and
after playing a round of golf. With this latter arrangement it is
possible to increase the strength of the induction field and still
obtain acceptably long lifetimes for the battery .
Embodiments of golf balls in accordance with the invention will now
be described, by way of example, with reference to the accompanying
drawings, in which:
FIG. 1 is a partially sectioned golf ball,
FIG. 2 is a perspective view of the spherical mass within the
centre of the golf ball shown on an enlarged scale,
FIG. 3 is one form of circuit suitable for employment in the golf
ball of FIG. 1, and
FIGS. 4 and 5 are two alternative forms of circuit.
Referring to FIGS. 1 and 2, the golf ball shown in the drawing
comprises an outer casing 1, a wound mass of elastic filament 2 and
a central core 3. In a normal golf ball the core 3 is a sphere of
rubber with a liquid centre. In a golf ball in accordance with the
invention the rubber core 3 contains a spherical recess 4 in which
is located a spherical mass 5.
The mass 5 is of hard set resin material (catalytically hardened
resin) of a diameter of 0.625 inch (15.9 mm) which with its
electric components weighs 3.5 grammes. The outside diameter of the
core 3 is 1.00 inch (25.4 mm), the core 3 being divided along a
diametric plane to allow the mass 5 to be located within the recess
4 before the core 3 is incorporated in the mass 2 and casing 1 in a
manner wholly conventional in the production of golf balls.
No alteration whatever is necessary in the components 1 and 2 shown
in the drawings but the core 3, as well as having a solid centre
rather than a liquid-filled centre, is fabricated from a softer
rubber than normal, the hysteresis of the rubber being chosen so
that the ball containing the mass 5 behaves in a similar manner to
a ball having a liquid-filled centre.
A simple circuit for incorporation in the mass 5 is shown in FIG. 3
and includes a transistor T (a Texas Instrument 2N3708), a battery
B (a mercury cell) a resistor R (560K ohms), two capacitors C1
(1,500 pS) and C2 (0.1.mu. F) and an intermediate-tapped coil L.
The circuit components cause oscillation at a frequency determined
by the natural frequency of the resonant circuit C1 L at a duty
ratio determined by the components C2 and R. The coil L has a turns
ratio 4:1 and is formed into a short cylindrical coil of diameter
0.60 inch (15.0mm).
The relative positioning of the components in the spherical mass 5
is important to ensure that the centre of gravity of the components
is roughly at the centre of the spherical mass.
The components shown within the dotted line in FIG. 3 can be
combined in an integrated circuit, to which are added the coil L,
the battery B and the capacitor C2.
The circuit shown in FIG. 3 operates in the same manner from the
moment of its completion to the moment the battery has run down.
This means that in order to ensure a life of several years, the
average power output must be exceedingly low and in turn this means
either a limited range at which a simple radio receiver will detect
the induction field or the use of a highly sensitive detector unit.
FIGS. 4 and 5 show alternative circuits which although somewhat
more complicated in their design do have the advantage of being
able to be switched "on" and "off" so that higher means power
outputs are obtainable during the "on" periods whilst still
providing a useful working life from a small mercury-cell.
Referring to FIG. 4, under quiescent conditions the base of a
transistor T2 is connected to its emitter via a resistor R2 so
there is no collector current flowing, other than the negligibly
small reverse current of the collector-base diode, hence there is
no bias current to remove the transistor T1 from its cut-off
condition. Also, the voltage developed across the dc. collector
load of the transistor T2 (V*) is approximately zero.
The tapped resonant circuit in the collector of the transistor T1
resonates at a frequency f.sub.o = 1/2 .pi..sqroot.LC3 where L is
the total inductance of the two primary sections of the coil, P1
and P2. If the golf ball is placed temporarily in the magnetic
induction field of an external exciting coil fed from an
oscillating source of frequency f.sub.o, an oscillating voltage
will appear across the resonant circuit inductance P1 + P2 and a
smaller voltage will appear across the secondary S. If the
secondary voltage is large enough, it will turn the transistor T1
ON into a Class C mode of operation, the necessary negative voltage
across the capacitor C4 being developed by the rectifying action of
the base-emitter diode of the transistor T1. (The maximum
peak-to-peak amplitude of the oscillation is limited to twice the
battery voltage across the coil P1, and to about 9 volts across the
secondary S, the 9 volts being the usual BE Zener breakdown voltage
of most silicon transistors, and the lowest value of the voltage on
the capacitor C4 is about half the 9 volts.) However, due to the
large feedback ratio S/P1, and due to the fact that the time
constant R1C4 of the base circuit is much larger than the
oscillation period, the oscillator will start to squeg immediately,
thereby turning itself off. The next burst of oscillation (in the
absence of the external exciter) will occur when the voltage on the
capacitor C4 is charged to about 0.6 volts through the resistor R1,
but this can happen only when V* is large than 0.6 volts.
On the first turning on of the oscillator, the transient decreasing
voltage on the capacitor C4 will pull down the base voltage of the
transistor T2 via the capacitor C6, and this capacitor will supply
a base current pulse if the transient voltage step exceeds 0.6
volts. The base current pulse, amplified by the current gain of the
transistor T2, charges up the capacitor C5 to a voltage V* near the
battery voltage. Hence the continual turning-on of the transistor
T1 after the initial switch-on is assured.
If the exciter voltage is kept on for a time longer than necessary
for start-up, the oscillator will start its successive bursts even
before the voltage on the capacitor C4 exceeds 0.6 volts. Hence the
transient step is reduced, and if it is reduced below a certain
critical level it is not capable of driving the transistor T2 and
V* drops to a negative value (approximately -4 volts). On the
sudden removal of the exciter voltage the oscillator will not be
able to start again and the golf ball therefore will be switched
OFF.
Switching ON or OFF therefore uses the same exciter, which could be
a part of the radio receiver used as the detector and could be
activated by a push-button switch. The exciter could even be the
ferrite aerial coil of the receiver, connected as an oscillator
while the push-button is depressed. The actual ON or OFF operation
would then be as follows:
Ball brought near (not too near) exciter and slowly removed =
SWITCH ON
Ball brought very near the exciter and quickly removed = SWITCH
OFF
FIG. 5 shows an alternative version of circuit. In this Figure a
capacitor C7 stores the bias voltage for a transistor T3 which is
charged up via a diode D. Squegging occurs with a time constant R3
C8 and bias current flows out of the capacitor C7 through the
resistor R3. Switching ON and OFF is done with an exciter as
before. On switching ON the capacitor C7 charges up to 41/2 volts
during the first rf burst. On switching OFF, as the pulse
repetition rate is increased, more current is drawn from the
smoothed supply and the supply voltage V.sub.s is reduced, thereby
reducing the oscillating voltage on P1 and therefore on S, which in
turn does not keep V* at its previous high value of 41/2 volts, and
the oscillator stops without the help from the external
exciter.
In the circuit of FIG. 5, C9 must be a large capacitor, while in
the circuit of FIG. 4 the values of the capacitors are small,
enabling the circuit shown in FIG. 4 to be produced in Integrated
Circuit form.
The circuit shown in FIG. 4 would conveniently employ components as
shown in the following Table:
TABLE
B = 1.4 volts
P1 = 8 turns
P2 = 100 turns
S = 30 turns
C3 = 3,000 pF
C4 = 1,000pF
C6 = 200pF
R1 = 1,000k
R2 = 100k
T1 = n.p.n
T2 = p.n.p
The circuits shown in FIGS. 4 and 5 can be "potted" in a spherical
mass of set resin in a similar manner to that employed with the
circuit of FIG. 2, the component parts being positioned to give a
centre of gravity as close to the centre of the mass 5 as
possible.
The circuit of FIG. 5 can be modified by placing the coil S, the
diode D and the resistor R4 in series with the emitter of the
transistor T3 and connecting the resistor R3 and the capacitor C8
to the base line.
* * * * *