ELECTRICAL STUNNING DEVICE Field of the Invention The present invention relates to an electrical stunning device, and to a conductive liquid for use in an electrical stunning device. The device delivers the stunning energy to a distant subject through streams of the conductive liquid, which is non-corrosive and non-toxic.

Background of the Invention Electrical stunning devices temporarily incapacitate a person, or an animal, by delivering a high-voltage shock in form of a non-injuring, low energy dose. The use of such devices limits injuries and mortality in dealing with assailants or intruders, on side of both unauthorized persons and authority forces. For example certain types of said devices brought a sharp decline in police killings in several American cities in 2003.

Various types of electrical stunning devices have been described. A device according to US 5, 282, 332, disclosing a stun gun disguised as a collapse umbrella, directly contacts the object to be incapacitated. US 4,691, 264 describes a stun gun for stunning a grounded person by a static charge through the air, wherein the charge is created piezoelectrically. US 5,675, 103 discloses a non-lethal weapon transmitting an electrical impulse through laser-ionized air, wherein the impulse, imitating physiological neuroelectric impulses, is transferred to the muscles of the person to be temporarily immobilized. A single current beam is emitted to a grounded target, or, alternatively, two current beams are employed. US 6,636, 412 discloses an electrical stun gun for incapacitating a human target, comprising spoolable wires and launchable darts. US 3,971, 292 employs two streams of a conductive fluid maintained at different potentials, which streams, together with the voltage source and with the target, complete

the electrical circuit. US 4,930, 392 discloses an apparatus for stunning a subject, comprising a ballistic stream of conductive fluid. A fluid is described, comprising sodium chloride, surfactant, and polyethylene glycol. US 5,103, 366 describes a conductive liquid for an electrical stun gun, comprising water, graphite, sodium chloride, preservative, and silver powder. US 5,225, 623 discloses a defense device for ejecting streams of charged fluid at a target, describing fluids comprising metallic mercury, graphite, lithium bromide, aluminum chloride, sodium chloride, glycerin, gels, and polyelectrolytes. Further, the following US patents also relate to non-lethal self defense device: 4, 846, 044; 5,409, 638; 5,625, 525; and 6,237, 461.

A disadvantage associated with most of available stun guns is the fact that the bearer of such a stun gun must be close to the subject to be stunned in order to reach him with the device and establish a physical contact between the gun's electrodes and the body of the subject. This may be rather risky to the bearer himself as he may be delivered, due to inadvertent or intentional contact with the subject, with the electric shock and become neutralized himself, or at least be seriously affected.

In developing new stunning devices, a fluid stream is an attractive alternative to launchable wires. A fluid to be utilized must comply with several requirements; firstly it must exhibit a high efficiency in transmitting the stunning energy; otherwise high voltages or high liquid volumes must be applied. However, not all fluids complying with the technical requirements of the electrical device comply also with the requirements that may be raised by the authorities who intend to use the device when-for example-dealing with public unrests, and who must take into consideration other than purely technological aspects, such as responsibility for public health and safety, and for eventual damages on public property. An ideal liquid for electrical stunning devices should be

able to transmit the required dose of energy without injuring the subject, and without unnecessary transmission losses. Furthermore, said ideal liquid should not contain any components that might be dangerous to incapacitated subjects or users or bystanders, said liquid should not inflict damages on property, and should be easily removable without contaminating the environment. It is therefore an object of this invention to provide a conductive liquid for electrical stunning devices which deliver the stunning energy through a fluid stream.

It is therefore an object of the present invention to provide a novel design for a non-lethal remote stunning device.

Another object of the invention is to provide such a device that has a relatively long effective range.

Yet another object of the invention is to provide an electrically conductive liquid that is suitable for use in a remote stunning device, and that is effective over a long range.

It is a further object of the invention to provide a conductive liquid for an electrical stunning device which is an aqueous solution or a water containing emulsion or suspension.

It is a still further object of the invention to provide a conductive liquid for an electrical stunning device, which liquid is non-corrosive and non-toxic.

It is also an object of the invention to provide a conductive liquid for an electrical stunning device, which enables relatively low transfer losses of energy.

It is also another object of the invention to provide a conductive liquid for an electrical stunning device, which has a high conductivity.

Other objects and advantages of the invention will appear as the description proceeds.

Summary of the Invention The invention provides a stun gun device for delivering electric shock to a distant object, the device comprising i) two canisters, each one being filled with conductive liquid, coupled to a compressed gas reservoir or to a spring mechanism and having a valve that is activated by the compressed gas or by the spring mechanism to exert pressure on the conductive liquid and to discharge it through an opening of said canister; ii) a handpiece comprising a triggering mechanism and two conduits, each being provided with a nozzle on one end and a connector on the other end, so that when the triggering mechanism is activated two jets of conductive liquids are allowed to be discharged from the canisters through the nozzles; and iii) electric circuitry for producing a high electric potential, in the order of at least several ten thousands of volts, across the two jets. Said device preferably comprises at least one safety latch in order to prevent inadvertent use of the device, said safety latch preferably comprising an obstacle to the entry of compressed gas into the canisters. In a preferred embodiment of the invention, said canister, said compressed gas reservoir, and said nozzle are aligned substantially linearly. Said triggering mechanism preferably comprises a trigger coupled to a conduit element cooperating with a conduit within the device through which the conductive liquid passes, which may be switched from a firing position, in which the conduit element is aligned with the conduit within the device allowing the liquid to pass through, to a safe position, in which the conduit element does not cooperate with the conduit within the device preventing the

liquid from passing through. Said valve is preferably provided with gasket rings. Said canisters are preferably replaceable and refillable. In a preferred embodiment of the present invention, external parts of said device are made from non-conductive insulating material.

The invention further relates to a liquid for use in an electrical stunning devices that utilize liquid streams for delivering electric shock to a subject to be incapacitated.

In a preferred embodiment of the invention, said liquid for use in electrical stunning devices is an aqueous solution or a water containing emulsion or suspension, and is non-corrosive and non-toxic. Said liquid has, at 25°C, a conductivity of at least 250 mS/cm, and preferably comprises a salt selected from ammonium chloride, ammonium bromide, ammonium iodide, ammonium nitrate, ammonium sulfate, potassium chloride, potassium bromide, potassium iodide, sodium bromide, and sodium iodide.

In a preferred embodiment, a liquid according to the invention comprises an agent for adjusting its rheological properties, preferably a polymer or a mixture of polymers, for example polymers such as polyethylene imine, polyethylene glycol, polyacrylamide, carboxymethyl cellulose, pectin, etc., preferably adjusting the viscosity at 25°C to a value of at least 50 cP, and more preferably to a value from 50 to 1000 cP. Said polymer has preferably a concentration of from 1 to 20 w/w%. A preferred liquid according to the invention comprises ammonium chloride, and has, at 25°C, a conductivity of at least 350 mS/cm.

Said conductive liquid may be, for example, a water-based mixture comprising a polymer, e. g. cationic polymer such as polyacrylamide.

Furthermore, said conductive liquid may comprise additives, such as hydrochloric acid, copper powder, silver powder, graphite powder, etc.

Furthermore, in accordance with preferred embodiments of the present invention, there is provided a method of applying electric shock onto a remote subject, the method comprising i) providing a reservoir of a conductive liquid mixture; ii) providing electric circuitry adapted to produce a high electric potential, in the order of at least several ten thousands of volts, across two electrodes; and iii) firing at least one jet of the conductive liquid electrically coupled to one of the two electrodes on the remote subject. In a preferred embodiment, two non-intersecting jets of the conductive liquid are fired on the subject, each jet electrically coupled to a different electrode.

Brief Description of the Drawings The above and other characteristics and advantages of the invention will be more readily apparent through the following examples, and with reference to the appended drawings, wherein: Fig. 1. illustrates a general view of a stun device in accordance with a preferred embodiment of the present invention ; Fig. 2. illustrates a cross-sectional view of the device shown in Fig. 1 (along line A-A); Fig. 3. illustrates the handpiece of the device shown in Fig. 1 ; Fig. 4. illustrates a cross-sectional view of the handpiece shown in Fig. 3 (along line D-D); and Fig. 5. illustrates a possible electric scheme for the stun gun of the present invention.

Detailed Description of the Invention The present invention provides a novel design for a non-lethal remote stunning device with a relatively long effective range, provided with replaceable canisters containing aqueous, non-corrosive and non-toxic liquid.

Reference is now made to Fig. 1 illustrating a general view of a stun device in accordance with a preferred embodiment of the present invention. A stun device in accordance with a preferred embodiment of the present invention comprises a handpiece 16 that includes a handle 18 and hull 22 that is fluidically connecting two canisters (12,14) filled with conductive liquid to two openings of the canisters, i. e. to two nozzles (26, 24) separately. The handpiece also includes a triggering mechanism, actuated by trigger 20. Cylinder 23 shown in the figure is a part of the triggering mechanism. Safety latch 15 (and 17 respectively) is optionally provided, where the"safe"position is when an obstacle prevents gas from exiting the compressed gas reservoir (see Fig. 2), and the"fire"position is where that obstacle is removed allowing gas to exit the compressed gas reservoir (into the main chamber of the canister).

Fig. 2 illustrates a cross-sectional view of the device shown in Fig. 1 (along line A-A). Each canister 12 (and 14 respectively) comprises a compressed gas reservoir 38 (and 40 respectively) connected, optionally via male- female connectors 42,46, (and 44,48 respectively), to a main chamber 31 (and 33 respectively) filled with a conductive liquid 30 (32 respectively).

Valve 54 (and 56 respectively), optionally provided with gasket rings 50 (and 52 respectively) is capable of being driven towards the nozzle end (24 and 26 respectively) of the canister by the force exerted on it when the compressed gas is released from the compressed gas reservoir into the main chamber. Fig. 2 depicts the canisters in an intermediate position, where the valves are about half-way through the main chambers, after some gas was released into the back portions (34 and 36 respectively) of the wet chambers. When the device is triggered (see explanation on the triggering mechanism hereinafter) compressed gas is being released into the main chamber it forces the valve forward, occupying the space created behind the valve. The conductive liquid is forced to evacuate the main chamber through the nozzle in the form of a jet, the pressure exerted by

the compressed gas reservoir being directly related to the distance covered by the jet. As the liquid evacuates the canister it passes through optional orifice adaptor 66 (and 68 respectively) through connector 27 (and 25 respectively-see Fig. 3) and through a conduit provided in the hull, on its way to the nozzle 24 (and 26 respectively). The compressed gas reservoirs are optionally provided with refilling openings (39,41), so as to facilitate long-term multiple use. The cross-sectional view as depicted in Fig. 2 is not horizontal with respect to the stun gun (see also Fig. 1). In this figure canister 31 is slightly elevated with respect to canister 33.

Fig. 3 illustrates the handpiece of the device shown in Fig. 1. Note the connectors at the back of the hull-25,27, which are designed to be plugged into the canisters, when armed.

Fig. 4 illustrates a cross-sectional view of the handpiece shown in Fig. 3 (along line D-D). The triggering mechanism is hereby explained with reference to Fig. 4. Trigger 20 is coupled to cylinder 23, which is provided with a conduit 62 passing it parallel to conduit 60 in the hull 22. Cylinder 23 is capable of being rotated by manipulating the trigger from a"safe" position, where cylinder 23 is twisted so that the passage 62 is not aligned with conduit 60, preventing flow from the canister to the nozzle, to a "firing"position, where upon pressing the trigger, conduit 62 is aligned with conduit 60 allowing flow through. Trigger 20 is preferably designed to resiliently retract to a default"safe"position when not pressed. Nozzle 24 (and 26 respectively) is preferably provided with external threading 64 over which electric wire may be coiled (the electrode of the electric circuitry). Insulation wrapping of the nozzle is recommended. Again it may be noted that the cross-sectional view is not horizontal with respect to the stun gun. Connector 25 is elevated with respect to connector 27 with respect to this figure. In this configuration the nozzle is made from a conductive material to ensure that the liquid is indeed energized. The

triggering mechanism depicted in the figures is not the only solution to the triggering of the device of the present invention, however the triggering mechanism shown in the figures was tested and produced very satisfactory results.

The pressure on the conductive liquid may be exerted by other means than shown in the above embodiment. In one preferred embodiment of the device of the invention, the pressure on the liquid is exerted by only one compressed gas reservoir with a branched conduit dividing the pressure among the two canisters. In another preferred embodiment of the device of the invention, the pressure on the liquid is exerted by a spring mechanism. Thus, compressed gas reservoirs 38 and 40 in Fig. 2 would be replaced by one reservoir or by a spring mechanism.

Fig. 5 illustrates a possible electric scheme for the stun gun of the present invention. There are many ways to design an electric circuit that are capable of producing a high-voltage shock (with very low amperage) employing standard batteries (most stun guns use 9V batteries). The design of the electric circuit is not a novel aspect of the present invention, and the circuit design shown in Fig. 5 is merely an example.

As two jets of electrolyte liquids are fired from the stun device, being energized with a high-voltage potential difference (which may be as high as a few hundred thousand volts, but of very low amperage), an electric shock is delivered to objects present within the range of the jets. In tests conducted by the inventors the range achieved was in the order of a few meters and up to dozens of meters.

It is asserted that for the stun gun to be effective, the jets must present good conductance throughout the desired range. This means that it is

desired that the jets be continuous, without cut-offs or turbulence. In order to facilitate that, it is recommended that the design of the stun gun be substantially linearly aligned, and as much as possible not tortuous, so that the flow within the device acquires very little if any lateral currents or turbulence. The inner surfaces of the device (the surfaces in contact with the liquid) should preferably be made to enhance smooth flow and not present obstacles to the flow. The design shown in the figures is designed to meet these requirements.

Salt water, mixed with long-chained cationic polymer, such as cationic polyacrylamide, provided a conductive liquid. Emulsions of salt water and polyacrylamide (up to some 20% in volume of the latter were used in the tests, but other concentrations should work too) produced good results with a device according to the invention. In other tests carried out by the inventors, hydrochloric acid was added to improve the conductivity of the jet. Other additives of conductivity enhancers such as copper powder, silver powder, coal powder, and graphite powder were also tested with the conductive liquid. The inventors note that other conductivity enhancing additives, such as powders of various conductive metals, and salts may also be used.

However, in shooting experiments, it was found by the current inventors that solutions of ammonium chloride in a concentration near to saturation, provided unexpectedly good results when compared with various prior art mixtures. Said solutions were combined with components adjusting their rheological properties, and obtained liquids were checked for their ability to transfer voltage pulses in a model device. The device consisted of two ejectors enabling to eject liquids in a narrow stream, a metal target onto which said liquid was ejected, and a high voltage low current AC source. The liquid left said ejector at a metal barrel. Two poles of said voltage source were connected to the barrels of said two ejectors.

The ejectors enabled to regulate the shooting distance to which the liquid was ejected, and the distance between said ejectors and said target varied.

A circuit comprising said two barrels, said metal target, and said voltage source could be closed by said two ejected liquid streams at certain shooting distances, but failed to close said circuit at greater distances. The maximal shooting distance was measured for each liquid several times, and the average value characterized the"shooting ability"of said liquid, i. e. , the ability to transfer the electrical pulse. The distance was, of course, a function of various parameters related to the model device, but the ratio of the distances for two different liquids characterized relative shooting abilities of said liquids.

Good shooting results were obtained with liquids based on concentrated aqueous solutions comprising at least one of salts selected from the group consisting of ammonium chloride, ammonium bromide, ammonium iodide, ammonium nitrate, ammonium sulfate, potassium chloride, potassium bromide, potassium iodide, sodium bromide, and sodium iodide. The term "concentrated", as used herein, relates to the proximity of a concentration to the concentration at saturation, and is used, for example, for concentrations of about 80% or higher of the saturation concentration. A liquid according to the invention provided, in various shooting experiments, distances that were several times greater than the distances for liquids prepared according to the prior art. A liquid according to the invention is characterized at 25°C by a conductivity of at least 250 mS/cm.

An additive, for adjusting rheological properties, may be comprised in said liquid, helping in creating a narrow, compact shooting stream. In one embodiment of the invention, the liquid has a viscosity at 25°C of at least 50 cP, and preferably from 50 to 1000 cP. A liquid according to the invention preferably comprises a polymer in an amount from 1 to 20 w/w%.

Thus, the liquid of the invention is suitable for use in electrical stunning devices utilizing liquid streams for transferring a stunning dose of electric energy. A high conductivity of a liquid according to the invention, preferably having at 25°C a conductivity of at least 350 mS/cm, serves well the purpose. Liquids having low efficiency in transferring the stunning dose necessitate either the use of higher voltage or wider liquid stream Too a high voltage increases complexity of the whole device, not speaking about possible safety problems, including risk for device users. Too a wide stream increases the used liquid volume. However, even a highly conductive liquid may be disqualified by the presence of certain components for the use in a stunning device. An example may be a high surfactant concentration, leading to excessive foaming, etc. On the other hand, even the liquids forming good conductive streams may be practically unusable when comprising components dangerous for the environment.

Disqualified are, e. g. , mixtures comprising mercury, etc. The liquid of this invention is safe from the viewpoint of both health and environment. No special precaution is required even for the personnel in regular contact with the device employing the liquid of the invention. The liquid of the invention is non-corrosive and non-toxic.

Thus the liquid of the invention is suitable for use in a stunning device intended for incapacitating an intruder to a property, an assailant, or other violent unauthorized person.

The stun gun of the present invention may be made from a variety of materials. In order to prevent self-electrocution, the external parts of the device ought to be made from non-conductive insulating materials (plastics may be suitable, possibly with fortification to withstand the pressure exerted by the compressed gas), or at least be covered with insulation. Tests conducted on a prototype of the stun gun shown in the figures showed very good performance. The device was found to be

effective in a range of 10 meters, and withstood pressures of up to 95 atm.

Repeated use of some hundred times did not bring about any failures and evidently the design is indeed very safe and robust.

When handling mass unrests, such as in soccer fan crowds, or when neutralizing a merely potentially dangerous person, the authority forces may be psychologically inhibited, or legally prevented, to use liquids damaging clothes of the subjects to be neutralized. Therefore, in certain situations, the liquids preferably do not contain components damaging the clothes, and in other situations it may be preferable not to use the liquids that visibly contaminate the clothes, e. g. liquids with a distinct color, such as liquids comprising graphite, or liquids with components difficult to wash, such as liquids comprising oily admixtures. In one embodiment, the invention provides a conductive liquid for use in an electrical stunning device that is non-corrosive and harmless in contact with the clothes, and that is easily washable.

For practical use, a liquid for a stunning device should be easily produced, handled, and stored, and preferably is made of cheap materials (avoiding, e. g. , using silver). For ejecting narrow streams, homogeneous liquids are preferred to mixtures containing sedimenting components. A preferred liquid according to the invention is a homogeneous simple mixture, either an aqueous solution or a water containing emulsion or a fine suspension, prepared from cheap materials. In addition, high salt concentrations prevent microbial growth, so that no preservatives are necessary. Said preferred liquid of the present invention thus provides an ideal liquid for use in a stunning device using a liquid stream for transferring a stunning dose of electric energy. A liquid according to the invention may be used in devices for shooting one stream at a grounded target, or in devices utilizing two streams having different electrical potentials, or devices employing a multitude of streams.

The invention will be further described and illustrated in the following examples.

Examples Relative abilities of various liquids to transfer voltage pulses were checked in a shooting model device. The device consisted of a target steel plate, and a commercial stun gun, Scorpy MAX (Czech Republic), that provided 22,000 volt AC pulses. The examined liquid was ejected from two C02- pressurized containers, 18 bars, through two metal barrels having an orifice of 1.4 mm. Said two barrels were connected to two poles of said stun gun. An ability of the ejected liquid to close a circuit consisting of said target, barrels, and said voltage source was checked for various distances between the ejectors and the target. A probe measured electric current in said circuit. Liquids were characterized by the maximal distance at which the circuit was closed.

Example 1 A liquid for stunning devices according to the invention was prepared by mixing, at 25°C, 29 g ammonium chloride, USP grade obtained from Sigma Israel, with deionized water to 100 ml, and 7.5 ml cationic polymer Alpine Floc A+++, obtained from Aqua Tech, Orbe, Switzerland. After 30 minutes stirring, concentrated ammonia was added to adjust pH to 5. The conductivity at 25°C was 430 mS/cm, and the viscosity 198 cP. The maximal shooting distance obtained with this liquid was in average 7 meters, calculated from 5 experiments.

Example 2 Two liquids were prepared, one containing 25 w/w% ammonium chloride with 4 w/w% Alpine Floc A+++ in water, and the other 25 w/w% sodium chloride with 4 w/w% Alpine Floe A+++ in water. The conductivity at 25°C

was 357 mS/cm and 184 mS/cm, respectively. The maximal shooting distance at the model device was 4 meters for the first liquid, and 1.5 meter for the second one, in both cases averaged from 5 measurements.

Of course, the distance will change with the experimental arrangement, but, as a skilled person will appreciate, the ratio for two different liquids will remain approximately the same, and will indicate which liquid is more advantageous for this purpose. While this invention has been described in terms of some specific examples, many modifications and variations are possible. It is therefore understood that within the scope of the appended claims, the invention may be realized otherwise than as specifically described.