U.S. patent number 3,819,108 [Application Number 05/284,019] was granted by the patent office on 1974-06-25 for crowd control stick.
This patent grant is currently assigned to General Marine, Inc.. Invention is credited to Richard James Jordan.
United States Patent |
3,819,108 |
Jordan |
June 25, 1974 |
CROWD CONTROL STICK
Abstract
An electric shock weapon is disclosed for use by officers in
maintaining order at public gatherings and for other crowd control
applications. The invention is embodied in an electrified stick or
in an electrified garment worn by the user. The device comprises at
least one pair of exposed conductors which are connected across a
high voltage power supply and adapted to be simultaneously engaged
with the anatomy of a would-be assailant and thus to ward off or
cause retreat of such person. In order to give warning of the
character of the device, and to lend a menacing appearance, a
sparking device is disposed on the weapon and connected across the
high voltage power supply to provide a spark discharge. In the
embodiment of the invention in an electrified stick a grip portion
is provided at the rear end and a slidable insulating sleeve is
disposed over a portion of the conductors and movable to the
forward end of the stick to provide an auxiliary gripping portion
for two-handed use of the stick. The high voltage power supply
preferably comprises a capacitor discharge system comprising a
battery energized transistor inverter and a voltage doubler
connected across a storage capacitor, with a self-switching
discharge circuit connected with an induction coil which in turn is
connected with the exposed conductors on the device. A timing
circuit and a silicon controlled rectifier are employed in the
self-switching discharge circuit.
Inventors: |
Jordan; Richard James
(Roseville, MI) |
Assignee: |
General Marine, Inc.
(Bloomfield Hills, MI)
|
Family
ID: |
23088548 |
Appl.
No.: |
05/284,019 |
Filed: |
August 28, 1972 |
Current U.S.
Class: |
231/7; 331/113A;
463/47.3 |
Current CPC
Class: |
A01K
15/02 (20130101); A01K 15/029 (20130101); F41B
15/04 (20130101); F41H 13/0018 (20130101) |
Current International
Class: |
A01K
15/02 (20060101); A01K 15/00 (20060101); F41B
15/00 (20060101); F41B 15/04 (20060101); B68h
011/00 () |
Field of
Search: |
;231/2E ;273/84 ;307/106
;321/2,15 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Chamblee; Hugh R.
Attorney, Agent or Firm: Reising, Ethington & Perry
Claims
The embodiments of the present invention in which an exclusive
property or privilege is claimed are defined as follows:
1. An electric shock weapon comprising a support member of
electrically insulating material, a power supply, at least one pair
of spaced conductors mounted on said member and being adapted for
simultaneous engagement with a subject, an induction coil with a
primary winding and a secondary winding, said secondary winding
being connected between said conductors, a capacitor and a charging
circuit connected therewith for recharging the capacitor after
discharge thereof, said charging circuit being connected with said
power supply, and a self-actuating switching means connected in
series circuit with said capacitor and the primary winding of said
coil, said switching means being effective to close said series
circuit in response to a predetermined voltage across said
capacitor whereby the capacitor is discharged through said primary
winding, said switching means being effective to open said series
circuit when the capacitor is discharged whereupon the capacitor is
recharged and the conductors are energized with repetitive high
voltage impulses from said secondary winding, said impulses being
of substantially uniform energy content.
2. The invention as defined in claim 1 wherein said support member
is a stick, plural pairs of spaced conductors extending lengthwise
of said stick, a first set of alternate conductors being connected
together at one end and a second set of alternate conductors being
connected together at the opposite end.
3. The invention as defined in claim 1 wherein said support member
is a garment.
4. The invention as defined in claim 1 wherein said support member
is portable by the user, a separate container enclosing said coil,
capacitor, charging circuit and switching means and adapted to be
carried on the person of the user, and a flexible electrical cable
extending between the coil secondary winding in said container and
said conductors on said member.
5. The invention as defined in claim 1 wherein said charging
circuit comprises an inverter, including a battery, a voltage
doubler connected between the inverter and said capacitor and
wherein said self-actuating switching means comprises a timing
circuit and a thyristor with its output connected in series with
said capacitor and said secondary winding and with its gate
connected to said timing circuit.
6. The invention as defined in claim 5 including a support bracket
mounted on said container and adapted to be received in a holder
carried on the person of the user, said support bracket being
provided with a pair of electrical terminals connected across said
battery and being adapted for connection with an external battery
recharging device.
7. The invention as defined in claim 2 wherein said stick includes
a handgrip portion at one end thereof, and an insulating sleeve
slidably disposed upon said stick over said conductors and being
movable between a position adjacent said handgrip portion to a
position adjacent the other end and constituting an auxiliary
handgrip portion.
8. An electric shock weapon comprising a support member of
electrically insulating material, at least one pair of spaced
elongated conductors mounted on said member, and being adapted for
simultaneous engagement with a subject, a pair of spaced electrodes
mounted on said member and having a spark gap therebetween disposed
exteriorly of said member so as to be readily visible to said
subject, a high voltage pulse generator having output terminals
connected across said electrodes to produce sparking therebetween
and connected across said conductors to apply an electric shock to
a subject in engagement therewith, said conductors being spaced far
enough from each other so that no spark discharge occurs directly
through the air therebetween, said pair of electrodes being spaced
close enough to each other so that a spark discharge occurs
directly through the air therebetween upon each pulse from said
pulse generator, the pulse generator frequency being high enough so
that the spark discharge appears to be continuous.
9. The invention as defined in claim 8 wherein said support member
is a stick, a handgrip portion at one end of said stick, plural
pairs of conductors disposed on said stick between said handgrip
portion and the other end of said stick, said pair of spaced
electrodes being disposed on said other end of said stick.
10. The invention as defined in claim 9 wherein one of said
electrodes includes a concave portion on said other end of the
stick and forms a light reflective surface, said other electrode
being disposed centrally of said one electrode, whereby light from
a spark discharge between said electrodes is reflected by said one
electrode.
11. The invention as defined in claim 9 wherein a first set of
alternate conductors is connected to a first common connector at
one end of the conductors, a second set of alternate conductors
being connected to a second common conductor at the opposite end of
the conductors, one electrode and the first common conductor being
connected to one of said output terminals, and the second common
connector being integral with said other electrode and being
connected to the other of said output terminals.
12. The invention as defined in claim 11 wherein said first common
connector is a ring disposed around said stick and the second
common connector having a ring-shaped portion integrally connected
with said concave portion and being disposed over the end of said
stick.
13. The invention as defined in claim 12 wherein said one electrode
is a metallic disc defining an annular spark gap with said first
electrode.
14. The invention as defined in claim 8 wherein said high voltage
power supply comprises an induction coil with a secondary winding,
a capacitor and a charging circuit connected therewith for
recharging the capacitor after the discharge thereof and a
self-actuating switching means for connected said capacitor across
the primary winding of said coil when the capacitor is charged,
whereby the conductors and said spaced electrodes are energized
with repetitive high voltage impulses, and said spark gap produces
a bright and noisy spark discharge.
15. An electric shock weapon comprising a stick of insulating
material, a handgrip portion at one end thereof, at least one pair
of conductors mounted on the surface of said stick in spaced
relation and extending substantially throughout the portion of the
stick from the handgrip portion to the other end of the stick, said
pair of conductors being adapted for simultaneous engagement with a
subject, a high voltage power supply having output terminals
connected across the pair of conductors for applying an electric
shock to a subject in engagement with said pair of conductors, and
an insulating sleeve slidably disposed upon said stick over said
conductors and being movable between a position adjacent said
handgrip portion to a position adjacent said other end and
constituting an auxiliary handgrip portion.
16. The invention as defined in claim 15 including plural pairs of
conductors, a first set of alternate conductors being connected
with a first common connector and a second set of alternate
conductors being connected with a second common connector, said
common connectors being connected respectively with the output
terminals of the high voltage power supply.
17. The invention as defined in claim 16 wherein said first common
connector is a ring disposed over said stick adjacent said handgrip
portion and wherein said second common connector is a ring disposed
over said stick and adjacent the other end thereof, and said sleeve
is slidably disposed between said rings.
18. The invention as defined in claim 17 including a pair of spaced
electrodes mounted on said other end of said stick and being
connected respectively with the output terminals of said power
supply.
19. The invention as defined in claim 18 wherein said high voltage
power supply comprises an induction coil with a secondary winding,
a capacitor and a charging circuit connected therewith for
recharging the capacitor after discharge thereof, and a
self-actuating switching means for connecting said capacitor across
the primary winding of said coil when the capacitor is charged,
whereby said conductors and said electrodes are energized with
repetitive high voltage impulses.
Description
This invention relates to crown control devices and more
particularly to devices adapted to be wielded or worn by officers
charged with maintaining order at public gatherings.
Heretofore it has been proposed to equip billies or night sticks
with means for impressing an electrical shock on persons who would
grasp or otherwise engage such devices in opposing the officer
wielding the same. The prior art devices have been wanting in
several respects and hence the usage thereof has been quite
limited. A particular problem has been that of providing the
required high voltage for a sufficiently long period of time from a
readily portable lightweight battery energized power supply.
Another difficulty in the prior art is that of the inability of the
device to deliver sustained repetitive shocking pulses without
manual intervention when the high voltage conductors are held by
the assailant. Another problem in the prior art is that of
facilitating use of the electrified stick in a two-handed manner
for pushing assailants as officers are trained to do, because of
the need for a nonshocking auxiliary handgrip portion near the
outer end of the stick. Such a nonshocking grip portion has been
undesirable because it makes it easier for an assailant to wrest
the stick from the officer.
The subject invention provides for greatly prolonged battery life
with an electrical circuit which sustains operation with the high
voltage conductors in short circuit, open circuit or a spark
discharge mode of operation. Furthermore, the circuit is adapted to
operate in a freerunning or self-switching mode so that repetitive
high voltage impulses are delivered without manual intervention,
even when the high voltage conductors are short circuited. Further,
the subject invention provides for the application of a train of
high voltage pulses which are substantially uniform in voltage
value and energy per pulse. This is accomplished by use of a
capacitor discharge system with an induction coil having its
primary winding connected to the capacitor through a self-actuating
switching means which is closed when the capacitor becomes charged.
A charging circuit for recharging the capacitor includes a battery
energized inverter which is coupled to the capacitor through a
voltage doubler. Preferably the self-actuating switching means
takes the form of a thyristor having its gate connected with a
timing circuit and its output being self-quenched by the associated
circuits. Such a high voltage power supply is preferably provided
in a separate container and is connected with the high voltage
conductors through a flexible cable. The power supply is admirably
suited to high voltage conductors incorporated in a stick or
incorporated in a garment or an item of apparel worn by the
user.
The invention also provides as an optional feature a visible and
noisy spark discharge to not only warn a would-be assailant of the
character of the device but also to lend a menacing appearance to
the device. This is accomplishd by connecting a pair of spark gap
electrodes across the high voltage supply and locating the same in
a prominent position on the device. In a preferred embodiment of
the invention in an electrified stick the electrodes are disposed
at the outer end of the stick and one electrode is formed as a
light reflector so that the spark is prominently visible. The
psychological affect of the spark discharge is enhanced by the
combined brightness and noise, which is achieved from the
repetitive impulses produced by a capacitor discharge system.
The invention additionally provides an electrified stick which will
apply an electric shock to an assailant who touches it anywhere
near the outer end and yet which provides an auxiliary handgrip
portion for the user at the outer end. This is accomplished by
means of a slidable insulating sleeve fitted over the stick and
electric conductors thereon and being movable from a position near
the handgrip portion at the rear of the stick to the outer end
thereof.
In the preferred embodiment of the invention in an electrified
stick, the stick itself is of wooden structure and supports plural
pairs of conductors extending from the handle portion to the outer
end. A first set of alternate conductors are connected to a common
electrical connector adjacent the handle portion with the common
connector taking the form of a metallic ring in engagement with
each of the first set of conductors. A second set of alternate
conductors are connected together through a second common connector
which preferably takes the form of a ring portion in engagement
therewith at the outer end of the stick. A spark gap is formed at
the outer end of the stick by a first electrode formed integrally
with the second connector and a second electrode spaced from the
first to form an annular spark gap and having a lead wire extending
centrally of the stick and connected by a radial pin to one of the
first set of conductors. Thus the plural sets of conductors and the
spark gap are energized from high voltage power supply leads in a
central bore of the stick by radially extending pins engaging
respectively one of the first and second sets of conductors. In
this construction the entire electrical circuit within the stick is
achieved by mechanical engagement without the need for solder
connections. Additionally, the slidable insulating sleeve is
constrained between the first and second connector rings mounted on
the stick.
A more complete understanding of the invention may be obtained from
the detailed description that follows, taken with the accompanying
drawings in which:
FIG. 1 is a pictorial view of the invention embodied in an
electrified stick;
FIG. 2 is a pictorial view of the high voltage power supply;
FIG. 3 shows the reverse side of the high voltage power supply;
FIG. 4 shows the invention embodied in a garment;
FIG. 5 is a view partially in section of the electrified stick
depicted in FIG. 1;
FIG. 6 is a view taken on lines 6-6 of FIG. 5; and,
FIG. 7 is a schematic diagram of the high voltage power supply.
Referring now to the drawings, there is shown an illustrative
embodiment of the invention in an electric shock weapon which is
especially adapted for use by an officer or other person for
controlling a crowd or maintaining order at a public gathering.
FIGS. 1, 2 and 3 illustrate the invention in an electrified stick
which, in general configuration, resembles the conventional billy
used by policemen. The device comprises a stick 10 constructed of
insulating material, preferably wood, which is formed with the
handle 12 and a shank 14. The handle 12 or grip portion is provided
with a wrist strap 16 secured in an annular slot and is also
provided with flutes 18, if desired, to facilitate gripping of the
handle. The shank 14 is provided with a plurality elongated
conductors 22 and 24 which are arranged in pairs and extend
longitudinally of the shank in spaced relation. It is noted that
each of the conductors is suitably of circular cross-section and is
inlaid by about one-half diameter into the surface of the shank. A
first set of alternate conductors 24 are electrically connected
together by a common connector in the form of a metallic ring 26
disposed over the stick and securing the conductors thereon. A
second set of alternate conductors 22 are electrically connected
together at the outer end of the stick by a common connector having
a ring portion 28 disposed over the end of the stick in securing
relation with the conductors 22. It is noted that the conductors 22
are axially spaced from the ring 26 and the conductors 24 are
axially spaced from the ring portion 28.
In order to electrify or energize the pairs of conductors 22 and
24, a high voltage power supply is provided in a separate container
or case 30. The output of the high voltage power supply is
connected through a flexible cable 32 to an electrical connector 34
in the base or rear end of the stick. The power supply is provided
with an on-off switch 36 readily accessible on the case 30.
Additionally, the case is provided with a window 38 for display of
a pilot lamp to indicate the on-off condition of the high voltage
power supply. On the back side of the case 30 a hanger or bracket
40 is provided to support the case from a receptacle adapted to be
carried on a belt worn by the user of the device. The bracket 40 is
provided with a pair of electrical terminals 42 and 44 for
connection with a battery charger receptacle when the device is not
in use.
Referring now to FIGS. 5 and 6, further details of construction of
the stick 10 will be described. The conductors 22 and 24, as
previously noted, are suitably of circular cross-section and are
preferably of relatively stiff metallic wire in order to withstand
rough treatment. One terminal of the high voltage power supply is
connected through the cable 32 and connector 34 to a pin 48 and
thence through the body of a connector 50 in the base of the stick
to a rigid conductor 52 extending through an axial bore in the
stick. A radially extending conductive pin 54 is disposed in a
radial passage in the stick between the conductor 52 and one of the
conductors 24. All of the conductors 24 are electrically connected
together through the ring 26. In a similar manner the other
terminal of the high voltage power supply is connected through the
cable 32, connector 34 to a pin 58 and thence through the connector
50 to a rigid conductor 60 in the bore of the stick. A radially
extending conductor pin 62 is disposed between the inner end of the
conductor 60 and one of the conductors 22. All of the conductors 22
are electrically connected together through the ring portion
28.
In order to provide a warning to a would-be assailant of the
character of the electrified stick and to impart a menacing
appearance, a sparking device 64 is provided on the exterior of the
stick at a prominent position. As shown in FIG. 5, the sparking
device 64 comprises a first electrode portion 66 which is formed
integrally with the ring portion 28 with the two portions together
constituting an end cap fitted over the end of the stick. The
electrode portion 66 is of concave configuration and is preferably
of a bright metal to provide a reflective surface. An electrode 68
of disc shape is disposed centrally of the electrode portion 66 and
forms an annular spark gap therewith. The electrode 68 is spaced
from the electrode portion 66 by an insulating washer 70 and is
provided with a stem or lead-in conductor 72 which extends through
an opening in the electrode portion 66 into an axial bore in the
stick. The electrode 68 is connected through the lead-in conductor
72 and a pin 74 extending therefrom to one of the conductors 24 and
thence to one terminal of the high voltage power supply. The
electrode portion 66 is connected through the ring portion 28 to
the conductors 22 and thence to the other terminal of the high
voltage power supply.
It will now be appreciated that with the terminals of the power
supply connected with the pins 48 and 58 on the stick 10, the sets
of conductors 22 and 24 will have the high voltage of the power
supply impressed therebetween. The conductors 22 and 24 are spaced
sufficiently to prevent spark discharge therebetween through the
air in use of the stick. However, the conductors are spaced close
enough so that engagement of the shank of the stick with the
anatomy of a person, will most likely cause simultaneous contact of
a pair of conductors 22 and 24 so that a localized high voltage
electric shock is applied to the person. The high voltage power
supply connected across the electrodes 66 and 68 of the sparking
device 64, and the length of the spark gap formed thereby are such
to cause an intense spark discharge. It is noted that the spark
discharge across the spark gap, which is in parallel with the pairs
of conductors 22 and 24, serves to regulate and limit the voltage
across the pairs of conductors 22 and 24.
In order to permit the user of the stick to grasp it in a
two-handed manner a slidable sleeve 80 of insulating material is
disposed over the shank of the stick. The sleeve 80 is an auxiliary
handgrip and provides a gripping portion long enough to accommodate
a person's hand and may be positioned along the shank of the stick
over the conductors 22 and 24 as desired. In single-handed use of
the stick the sleeve 80 would normally be parked at the rear
portion adjacent connector ring 26 which serves as a stop for the
sleeve. This leaves the conductors 22 and 24 exposed at the outer
end of the stick for contacting persons opposing the stick. When
the user desires to use the stick in a two-handed manner he merely
grasps the sleeve with his other hand and slides it toward the
outer end of the stick. The user is fully insulated from the high
voltage of the conductors 22 and 24 by the sleeve in any position
thereof on the shank of the stick. The connector ring portion 28
serves as a stop for the sleeve at the outer end of the stick.
The high voltage power supply circuit for the electrified stick is
shown in schematic form in FIG. 7. This circuit is disclosed and
claimed in my copending patent application Docket P-303 filed on
even date herewith and assigned to the same assignee as the present
invention and entitled "High Voltage Pulse Generating Circuit." The
power supply circuit comprises, in general, a transistor inverter
110 which supplies alternating voltage to a voltage doubler 112,
which in turn delivers charging current to a storage capacitor 114.
The storage capacitor is connected with a voltage transforming
means 116 through a thyristor 118. The thyristor is connected with
control means 120 which turns on the thyristor at controlled
intervals to discharge the capacitor 114 and thereby develop high
voltage impulses across the output of the voltage transforming
means 16.
Considering the circuit in greater detail, the inverter 110
suitably takes the form of a conventional pushpull transistor
oscillator. As such, it comprises a pair of NPN power transistors
122 and 124, a direct voltage source such as a battery 126 and an
output transformer 128. The transistor 122 has its output circuit
from collector to emitter connected across the battery 126 through
an on-off switch 130 and a primary winding 132 of the transformer
128. Similarly, the transistor 124 has its output extending from
collector to emitter connected across the battery 126 through the
switch 130 and a primary winding 134, which has one terminal in
common with one terminal of the primary winding 132 and
constituting a center tap on the combined windings 132 and 134. The
transistor 122 has an input circuit from base to emitter, including
a resistor 136 and a feedback winding 138. A forward bias for the
transistor 122 is provided by a voltage divider comprising a
resistor 140 and the resistor 136. Similarly, the transistor 124
has an input circuit extending from base to emitter through a
resistor 142 and a feedback winding 144. A forward bias is provided
for this transistor by a voltage divider comprising a resistor 146
and the resistor 142. The output transformer 128 is also provided
with a secondary winding 148 which, in operation of the oscillator,
produces an output alternating voltage.
The operation of a transistor inverter of the type described is
well known and need not be described in detail. Suffice it to say
that upon closure of the switch 130, both of the transistors 122
and 124 are forwardly biased and both become conductive. However,
because of inherent circuit unbalance one becomes more conductive
than the other through its associated primary winding and
consequently positive feedback to that transistor through the
associated feedback winding drives that transistor quickly into
saturation and the induced voltage in feedback winding of the other
transistor drives it to cut-off. When current saturation is reached
in the first transistor, the feedback voltage is reduced to zero
and the decreasing current in the primary winding of the conductive
transistor results in collapse of the magnetic flux and a reversal
of polarity of the induced voltages in the feedback windings.
Accordingly, the first transistor is cut-off and the other
transistor becomes conductive and is driven to current saturation.
This cycle of operation is repetitive at a frequency determined by
the parameters of the oscillator circuit and consequently an
alternating voltage is developed across the output terminals of the
secondary winding 148. As is well known, the output voltage has a
somewhat rectangular waveform due to the rapid switching
characteristics of the transistors 122 and 124.
The voltage doubler 112 is adapted to charge the storage capacitor
114 toward a voltage value equal to twice the peak value of the
alternating voltage of the secondary winding 148. For this purpose
the voltage doubler comprises a first rectifying diode 152,
connected in series with a holding capacitor 154 across the
secondary winding 148. The circuit also includes a second
rectifying diode 156 connected between the junction of capacitor
154 and diode 152 and one terminal of the storage capacitor 114. A
blocking diode 158 is connected between the other terminal of the
storage capacitor 114 and the other side of the diode 152. In the
operation of the voltage doubler 112 the holding capacitor 154 will
be charged through the rectifying diode 152 during one half-cycle
of the alternating voltage toward the peak value of voltage across
secondary winding 148. During this half-cycle the blocking diode
158 blocks current flow to the storage capacitor 114 and the
rectifying diode 152 prevents discharge of the holding capacitor
154 through its charging circuit following the first half-cycle.
During the succeeding half-cycle, with the polarity across the
secondary winding reversed, the voltage thereof is additively
combined with the voltage across the holding capacitor 154 in
series with the rectifying diode 156, the storage capacitor 114 and
the blocking diode 158. Accordingly, the storage capacitor 114 is
charged toward a voltage equal to twice the peak value of voltage
across the secondary winding. For the purpose of providing a visual
indication of the operative condition of the inverter 110, a neon
lamp 162 is connected across the secondary winding 148 with a
series resistor 164 and hence is illuminated when the inverter is
running.
The discharging circuit for the storage capacitor 114 extends
through the primary winding 166 of the voltage transforming device
116 and thence through the output, i.e., anode to cathode of the
thyristor 118 which preferably takes the form of a silicon
controlled rectifier. As is well known, a thyristor is a rectifier
of the solid state semi-conductor type which becomes forwardly
conductive from anode to cathode when the voltage impressed
thereacross exceeds a threshold value and when the current from the
gate to cathode exceeds a predetermined value. The anode to cathode
remain conductive, even after the gate to cathode current is
reduced to zero, so long as voltage applied thereacross exceeds the
threshold value. Thus the thyristor or silicon controlled rectifier
118 is turned on only by the requisite gate current and can be
turned off only by the requisite reduction of cathode to anode
voltage to quench the output.
The control means 120 for controlling the turn-on of the thyristor
118 is adapted to correlate the switching point with the value of
voltage across the storage capacitor 114. For this purpose the
control circuit comprises a voltage divider including a resistor
170 and a capacitor 172 in series across the storage capacitor 114.
A voltage threshold device, such as a semi-conductor diode 174,
poled for forward conduction, is connected between the junction of
resistor 170 and capcitor 172 and the gate of the thyristor 118.
Thus the input of the thyristor 118 is connected across the voltage
divider capacitor 172 and when the voltage across the capacitor
reaches a predetermined value the diode 174 will conduct in the
forward direction and the requisite turn-on current will flow from
gate to cathode in the thyristor 118 and thereby trigger or turn-on
the thyristor. This allows the storage capacitor 114 to discharge
through the thyristor and the primary winding 166 of the voltage
transforming device 116 and thereby develop a high voltage pulse in
secondary winding 176 which constitutes the high voltage output and
the terminals thereof are connected through cable 32 to the pins 48
and 58 (FIG. 5). The voltage transforming means 116 preferably
takes the form of a high voltage spark coil with the primary and
secondary windings having a common connection with constitutes an
intermediate tap on a single coil and serves as a common return or
ground conductor. Thus the transforming means has the configuration
of an autotransformer, as is commonly used for ignition coils.
Operation of the inventive high-voltage pulse generating circuit is
as follows: When the switch 130 is closed the inverter 110 is
operative and produces an alternating output voltage across the
secondary winding 148. On each full cycle of the oscillator 110 the
storage capacitor 114 is charged toward a value equal to twice the
peak of the alternating voltage across the secondary winding.
During the first half-cycle the capacitor 154 is charged and during
the second half-cycle the voltage across the capacitor 154 and the
voltage across the secondary winding 148 are additively combined
across the storage capacitor 114, whereby it is charged toward a
value equal to twice the peak voltage across the transformer
secondary. As the capacitor 114 is charged, the voltage thereacross
is also applied across the voltage divider including the series
resistor 170 and capacitor 172. During the initial part of this
charging interval the thyristor 118 is turned off and accordingly
no current flows through the primary winding 166 of the coil 116.
As the voltage across the capacitor 114 rises toward its peak value
the voltage across the capacitor 172 also increases until the
output of the voltage divider 120 exceeds the threshold value for
forward conduction of the diode 174. At this point the diode 174
becomes conductive and the current flow from gate to cathode of the
thyristor 118 is sufficient to turn on the thyristor which
thereupon connects the primary winding 166 directly across the
storage capacitor 114. A discharging circuit is thus completed
through the primary winding of the coil 116 and the resulting
primary current impulse produces a high voltage output pulse across
the secondary winding 176. The capacitor 114 is quickly discharged
through the thyristor 118 and the thyristor is turned of in
readiness for the next cycle of operation. The turn-off or
quenching of the thyristor 118 is believed to be accomplished in
either of two ways depending upon the operating conditions. When
the high voltage across the secondary winding 176 is allowed to
discharge, the energy in the capacitor is exhausted, thereby
terminating current flow through the thyristor. When the high
voltage across the secondary winding is not allowed to discharge,
the reflected counter electromotive force in the primary winding
166 terminates the current flow through the thyristor. Thus the
thyristor 118 is turned off at the end of the first cycle and the
succeeding cycle commences. As previously described, the first
half-cycle thereof is operative to charge the capacitor 154 and the
second half-cycle is operative to apply the transformer secondary
voltage and the voltage of capacitor 154 to the storage capacitor
114. When a predetermined voltage is reached, the control circuit
120 turns on the thyristor to discharge the capacitor 114 through
the primary winding 166 to produce a high voltage pulse in the
output winding 176, as previously described. This operation is
repetitive at a rate depending upon the time constant of the
resistor 170 and the capacitor 172 with a maximum corresponding to
the frequency of the transistor oscillator 110. A train of high
voltage output pulses is produced across the secondary winding of
the transforming means 116.
The train of high voltage pulses are applied through the cable 32
to electrify the stick 10. Accordingly, the high voltage will be
impressed across the sets of conductors 22 and 24. The high voltage
will also be impressed across the electrodes 66 and 68 of the
sparking device 64. The voltage of each pulse is high enough to
cause a spark discharge between the electrodes 66 and 68 but it is
insufficient to cause discharge between the adjacent conductors 22
and 24 which are more widely spaced than the spark gap electrodes.
The sparking device 64 produces spark discharges of considerable
intensity across the annular gap and the reflective surface of the
electrode 66 enhances the visual effect. Additionally, the spark
tends to wander or travel around the annular gap. The high voltage
power supply is effective to fire the spark gap at the repetition
rate of the high voltage pulses which is in the audible frequency
range and the repetitive discharges thus produce a noise in the
nature of a hissing sound. Consequently the sparking device lends a
menacing appearance to the electrified stick even though the
sparking device itself is rather harmless.
The effectiveness of the electrified stick is provided by the high
voltage conductors 22 and 24. Although the voltage is of the order
of several thousand volts, the device is not lethal and does not
inflict lasting injury upon the person who engages the conductors.
Instead, by reason of the high voltage being applied across
adjacent conductors a localized area of the person's anatomy is
directly affected. The high voltage power supply delivers a
measured amount of electrical energy by each discharge of the
storage capacitor and hence by each pulse of high voltage. When a
person grasps the stick and his hand bridges the high voltage
conductors high voltage shocking pulses will be administered at a
repetition rate corresponding to the frequency of inverter. The
power supply will function with the high voltage output in an open
circuit, spark discharge or short circuit condition. Even in the
short circuit mode the current drain on the battery remains
substantially the same as in other modes because the capacitor
discharge system of the power supply will deliver only a metered
amount of energy per pulse. The high voltage output circuit is
effectively isolated from the battery supply in the inverter. Thus
the power supply may be operated a relatively long time without
recharging the batteries.
A modification of the invention is illustrated in FIG. 4. In this
modification the invention is embodied in a garment to be worn by
the user of the device. In particular, a glove of leather or other
insulating material is provided with a pair of conductors 202 and
204 which extend in spaced relation along the length of the glove.
The conductors 202 and 204 are provided with electrical connectors
206 and 208 respectively, which suitably take the form of snap
fastener elements adapted to be connectd to the high voltage power
supply through a flexible cable which terminates in mating snap
fastener elements, not shown. It will now be appreciated that the
glove 200 may be connected with a high voltage power supply of the
same construction as shown in FIGS. 2, 3 and 7. When the power
supply is energized during the use of the glove for crowd control
purposes the simultaneous engagement of the conductors 202 and 204
with the anatomy of a would-be assailant produces an electric shock
sufficient to ward off the assailant.
Although the description of this invention has been given with
reference to a particular embodiment, it is not to be construed in
a limiting sense. Many variations and modifications will now occur
to those skilled in the art. For a definition of the invention
reference is made to the appended claims.
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