Abstract:
An electronic vehicle disabler system and method uses a current supply capable of delivering an electrical current to a fleeing or moving vehicle that inhibits self-propelled movement of the vehicle. The electrical current is delivered by establishing a momentary forward current path between the vehicle and the current supply, at the same time that a return current path between the vehicle and current supply is established. The forward and reverse current paths may, e.g., include electrically conductive wires or electrically conductive streams of fluid or gas. The forward and reverse current paths are electrically coupleable to the fleeing vehicle through a variety of direct conductive linkages that are temporarily or permanently laid down on a roadway over which the fleeing vehicle passes, or that are coupled to the fleeing vehicle from a pursuing vehicle.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the stopping of vehicles, and more particularly to such stopping using electromagnetic energy. Even more particularly, the present invention relates to the stopping of self-propelled vehicles using high-current pulses of electromagnetic energy coupled to the vehicle through a direct contact. 
     Heretofore, law enforcement officers, and others with a legitimate need to stop, or arrest, vehicles, had very few choices. Roadblocks and checkpoints employing barricades made of heavy wood, concrete or police mobile units, i.e., police vehicles, are commonly used, but are of limited effectiveness due to high staffing requirements, and the ability of the vehicle that is to be stopped to “run” the roadblock by speeding through the barricades. Such roadblocks typically require the services of several police officers, and in the event the vehicle “runs” the roadblock, often requires that such officers engage in a high-speed chase. 
     High-speed chases used to arrest vehicles that have “run” a roadblock, or to apprehend other fleeing vehicles, are very dangerous for the officer, for bystanders, and for the vehicle&#39;s occupants. As a result, most police departments require their officers to “break off” high-speed pursuit whenever the lives of police officers, bystanders, or occupant&#39;s of the fleeing vehicle are in danger. As a result, a significant number of vehicles evade stops by police officers. 
     Another situation that results in high-speed pursuit is when vehicles “run” toll booths, such as are common at the entrances to tollways or tollbridges, or border checkpoints or inspection points. For example, various states and the United States government have checkpoints and/or inspection points at their borders. In the event a vehicle “runs” the checkpoint, border agents, e.g., Border Patrol Officers, are forced to either pursue such vehicles or to permit them to enter illegally. On several occasions, high-speed pursuit by United States Border Patrol Officers has resulted in death or serious injury to the officers, bystanders or fleeing vehicle occupants. 
     One attempt to solve this problem is through the use of spike bars that can be activated, i.e., advanced or protruded into the roadway, so that small controlled leaks are inflicted in the vehicle&#39;s tires. Soon after the leaks are inflicted, the vehicle&#39;s motion is impeded and high speeds are no longer possible. The spike bars are retracted by the pursuing officer so that his or her mobile unit, as well as other vehicles, can pass over the spike bar without damage being inflicted to the mobile unit&#39;s or other vehicle&#39;s tires. Unfortunately, spike bars are only useful in permanently installed locations, and cannot be incorporated into a discrete portable unit, or mounted in the pursing mobile unit. 
     Another attempt to solve the above problem is through the use of microwave radiation that disables or inhibits electronic components, such as electronic control modules for controlling electronic fuel injectors, or distributors, and the like. To applicants&#39; knowledge, microwave radiation has never been commercially exploited for several reasons. One reason is that the microwave energy cannot be directed against a single vehicle. Thus, when a microwave radiation device is employed, all or many of the vehicles in the vicinity of the fleeing vehicle may also be temporarily or permanently disabled. The disabling of such a group of vehicles creates a particularly acute problem in busy traffic areas, where a single disabled vehicle could be pulled safely to the side of the road, but a large number of such vehicles cannot all be safely moved aside. 
     A further attempt to address the problem includes the installation of vehicle disabling equipment in all commercially available vehicles. The vehicle&#39;s disabling equipment normally remains off, but when activated by a law enforcement officer disables one or more key systems within the vehicle, e.g., the fuel pump or ignition system. Problematically, however, such vehicle disabling systems require that each vehicle be equipped with the disabling equipment, adding additional cost to each vehicle sold. Furthermore, because the equipment is under the control of the vehicle&#39;s owner, such equipment could easily be tampered with and possibly disabled by the vehicle&#39;s owner. 
     Thus, a significant need exists for an improved solution to the problem of arresting a vehicle. The present invention advantageously addresses the above and other needs. 
     SUMMARY OF THE INVENTION 
     The present invention advantageously addresses the needs above as well as other needs by providing a system and method for stopping self-propelled vehicles using high-current pulses of electromagnetic energy that are coupled directly into the vehicle to be stopped from a suitable current source. 
     The invention may be characterized as an electronic vehicle disabler system for inhibiting self-propelled movement of a vehicle. The system includes a current supply capable of delivering a current that inhibits self-propelled movement of the vehicle; a forward current path coupled to the current supply, and a return current path coupled to the current supply. The forward and reverse current paths may, e.g., include electrically conductive wires or electrically conductive streams of fluid or gas. The forward and reverse current paths are electrically coupleable to the vehicle. The forward current path delivers the current from the current supply to the vehicle whenever the return current path is electrically coupled to the vehicle, and the return current path returns the current to the current supply from the vehicle whenever the forward current path and the return current path are electrically coupled to the vehicle. As a result, whenever the forward current path and the return current path are electrically coupled to the vehicle a sufficiently large current flows through the vehicle so as to hinder or disable its electronic/electrical systems, thereby inhibiting vehicle movement. 
     The present invention may also be characterized as a method for inhibiting self-propelled vehicle movement including: (a) contacting the vehicle electrically with a first current path; (b) contacting the vehicle electrically with a second current path; (c) generating a current that is capable of inhibiting self-propelled movement of the vehicle; and (d) delivering the current through the first and second current paths so as to inhibit the self-propelled movement of the vehicle 
     It is a feature of the invention to disable or inhibit self-propelled movement of a vehicle. 
     It is another feature of the invention, in one embodiment, to achieve such disabling or inhibiting using a portable electromagnetic vehicle disabler system. 
     It is a further feature of the invention, in another embodiment, to achieve such disabling or inhibiting using an electromagnetic vehicle disabler system that is carried by a mobile unit, i.e., a pursing vehicle. 
     It is an additional feature of the invention, in a further embodiment, to achieve such disabling or inhibiting by contacting the vehicle with one or more electrically conductive streams of fluid or gas. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein: 
     FIG. 1 is a schematic view of a vehicle coupled to an electromagnetic vehicle disabler made in accordance with the present invention; 
     FIG. 2 is a perspective partial cut-away view of a vehicle in electrical communication with a man-portable electromagnetic vehicle disabler system made in accordance with one embodiment of the system shown in FIG. 1; 
     FIG. 3 is a perspective view of the man-portable electromagnetic vehicle disabler system shown in FIG. 2; 
     FIG. 4 is a perspective view of a permanently-installed electromagnetic vehicle disabler system made in accordance with another embodiment of the system shown in FIG. 1; 
     FIG. 5 is a side view of a further embodiment of the system shown in FIG.  1  and shows a vehicle-mounted electromagnetic vehicle disabler system having a pair of electrically conductive wires that are deployed from a pursuing vehicle against a pursued vehicle so as to put the pursued vehicle into electrical communication with the wires; 
     FIG. 6 is a side view of a variation of the embodiment shown in FIG. 5, and shows a vehicle-mounted lectromagnetic vehicle disabler system having a pair of electrically conductive fluid streams that are discharged from a pursuing vehicle against a pursued vehicle so as to put the pursued vehicle into electrical communication with the fluid streams; 
     FIG. 7 is a side view of an additional embodiment of the system shown in FIG.  1  and shows a vehicle-mounted electromagnetic vehicle disabler system having a single electrically conductive wire that is deployed from a pursuing vehicle against a pursued vehicle so as to put the pursued vehicle into electrical communication with the wire; 
     FIG. 8 is a side view of a variation of the additional embodiment shown in FIG. 7, showing a vehicle-mounted electromagnetic vehicle disabler system having a single electrically conductive fluid stream that is discharged from a pursuing vehicle against a pursued vehicle so as to put the pursued vehicle into electrical communication with the fluid stream. 
    
    
     Corresponding reference characters indicate corresponding components throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The following description of the presently contemplated best mode of practicing the invention is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of the invention. The scope of the invention should be determined with reference to the claims. 
     Referring first to FIG. 1, a schematic view is shown of a vehicle  10  coupled to an electromagnetic vehicle disabler made in accordance with the present invention. The vehicle  10  can be any type of self-propelled mobile personal property. For example, the vehicle may be a car, a motorcycle, a truck, a bus, etc. The vehicle  10  is powered by an internal combustion engine  12 , however any source of mechanical power that relies on electrical signals, such as an electronic fuel injection system or an electronic ignition, may be subject to the disabler features of the present invention. As shown, the internal combustion engine  12  includes an electronic control module (ECM)  14 , and a distributor control module (DCM)  16 , such as are known in the art. 
     The present invention arrests the vehicle  10  by coupling it to a first current path  18  and to a second current path  20 . The second current path  20 , which serves as a return current path, can include earth ground  20 ′, or can include an alternative return current path  20 ″, such as an electrically conductive wire, or electrically conductive fluid or gas stream. The first current path  18 , or forward current path, can also include an electrically conductive wire, or electrically conductive fluid or gas stream. The first (forward) and second (return) current paths  14 ,  16  are coupled to a current supply  21 . The current supply  21  generates an electrical current that passes through the forward current path  14 , to the vehicle  10 , and to the return current path  16 . A switch  23  within or coupled to the supply  21  allows the current to be supplied or not supplied as desired. In the event either of the forward or return current paths  14 ,  16  are decoupled from the vehicle  10 , the current ceases flowing through the current paths  14 ,  16 . However, in the event both the forward and return current paths  14 ,  16  are coupled to the vehicle  10 , as is shown in FIG. 1, portions of the current pass through electrically conductive components throughout the vehicle  10 . For example, portions of the current pass through a metallic body, frame, and wiring of the vehicle  10 . Specifically, portions  22 ,  24  of the current pass through the electronic control module  14  and/or the distributor control module  16  via, e.g., the wiring of the vehicle  10 . 
     The electronic control module  14  and/or the distributor control module  16  are highly sensitive electronic components commonly found in internal combustion engines of modern automobiles and other vehicles. The electronic control module  14  controls an electronic fuel injection system within the internal combustion engine  12 , and the distributor control module  16  controls an electronic ignition system within the internal combustion engine  12 . As one of the portions  22  of the current passes through the electronic control module  14 , it partially or fully disables the electronic control module  14 , which causes the internal combustion engine  12  to run poorly, i.e., roughly, and to not be able to run or operate at high speeds, or alternatively, to not run at all. Similarly, as another of the portions  24  of the current passes through the distributor control module  16 , it partially or fully disables the distributor control module  16 , which causes the internal combustion engine to operate poorly, or not run at all. In this way, the vehicle  10  is inhibited or disabled from self-propelled movement, i.e., the vehicle is arrested. 
     The electrical current from the current supply  21  is from 150 to 5000 amps, and is preferably 300 to 4000 amps, e.g., 3000 amps. The current can be either pulsed direct current, or alternating current, including pulsed alternating current. Alternating current is preferred in the event the return current path includes earth ground, and is particularly preferred when the return current path includes highly insulative components, such as tires of the vehicle  10 , in which case alternating current is needed to facilitate electromagnetic coupling between the tires and earth ground. To achieve such coupling, the frequency of the alternating current is between 1 MHz and 500 MHz, and is preferably between 10 MHz and 25 MHz. 
     The current supply  21  stores about 1 milli Coulomb (mC) of charge, and 100 Joules (J) of energy. The inductance of the charge supply is about 1 μH, and the voltage at which the current is delivered is small enough so that it does not break down along the surface of the vehicle  10  and cause undesirable arcing. The voltage delivered is between 1 kV and 50 kV, preferably 10-15 kV. The current supply  21  includes a capacitive charge source, an electrolytic (i.e., not reversible) capacitive charge source, a shock initiated charge source and/or a superconductive charge source. 
     Referring next to FIG. 2, a perspective partial cut-away view is shown of the vehicle  10  in electrical communication with a man-portable electromagnetic vehicle disabler system. The vehicle  10  is shown passing over a flat mounting plate  30  to which two protruding electrodes or wires are affixed. The mounting plate  30  may also be referred to as a driving surface  30 . The driving surface  30  is placed on top of a road surface  32 . Projecting from the driving surface  30  are a first electrically conductive wire  34  and a second electrically conductive wire  36 . The electrically conductive wires  34 ,  36  serve as the forward and reverse current paths  18 ,  20  of FIG. 1, respectively, and are connected to a current supply unit  38 , which serves as the current supply  21  of FIG.  1 . 
     The current supply unit  38  is preferably battery powered or powered from a portable energy source (such as a police van), and, together with the driving surface  30 , is preferably portable. The dimensions of the driving surface are about 8 to 10 ft. ×1 ft. ×1 in. 
     In use, the current passes from the current supply unit  38  to the first electrically conductive wire  34 , through the vehicle  10  (and components therein, such as the electronic control module and distributor control module of FIG. 1) to the second electrically conductive wire  36 . While much of the electrical current that is injected into the vehicle by the present invention simply flows from one ground point to another, the magnitude of the ground current that thus flows is sufficiently large so as to induce other currents to flow in the electrical circuits, e.g., the DCM  16  and/or the ECOM  14 , of the vehicle so as to disable and/or bum out such electrical circuits. 
     The electrically conductive wires  34 ,  36  protrude up from the surface  30  and assume a substantially normal position relative to the driving surface  30  when the vehicle  10  is not passing over the driving surface  30 . The electrically conductive wires preferably protrude from the driving surface at least 10 inches, and no more than about 18 inches. When the vehicle  10  is passing over the driving surface  30 , the electrically conductive wires  34 ,  36  bend over, as shown in FIG. 2, and mechanically and electrically engage the underside (or undercarriage) of the vehicle  10 . When the electrically conductive wires  34 ,  36  are in the substantially normal position, i.e., when the vehicle  10  is not passing over them, they are open circuited, i.e., the current does not flow between them. When they electrically engage the vehicle  10 , the vehicle electrically couples the electrically conductive wires  34 ,  36  to each other, allowing the current to flow from the first electrically conductive wire  34  through the vehicle  10  to the second electrically conductive wire  36 . Thus, there is no need for a switching device in the current supply unit to activate the vehicle disabler system. A switching device is used, however, to deactivate the vehicle disabler system so that vehicles that are not to be disabler can pass over the driving surface  30  without having the current pass through them, i.e., without being disabler. 
     Referring next to FIG. 3, a perspective view is shown of the man-portable electromagnetic vehicle disabler system. The driving surface  30  is shown on top of the road surface  32 . The electrically conductive wires  34 ,  36  project from the driving surface  30  in a substantially normal direction, and the current source unit  38  is coupled to the electrically conductive wires  34 ,  36 . 
     Referring next to FIG. 4, a perspective view is shown of a permanently-installed electromagnetic vehicle disabler system. The road surface is shown  32 , but the driving surface  30  (of FIG. 3) is not shown, because in the permanently-installed electromagnetic vehicle disabler system, the road surface  32  serves to mechanically support the first and second electrically conductive wires  34 ,  36 . Except as denoted below, the permanently-installed electromagnetic vehicle disabler system is similar to the man-portable electromagnetic vehicle disabler system described herein. The current supply unit  38  used with the permanently-installed electromagnetic vehicle disabler system of FIG. 4 may be permanently installed underground, and can utilize alternating current power-lines as a power source (The man-portable disabler system of FIG. 3 may also be plugged into such an A.C. power source line if a suitable outlet is nearby). Such underground placement serves to prevent theft and vandalism of the charge supply unit  38  (but eliminates the portability of the charge supply unit  38 ). The charge supply unit of the permanently-installed vehicle disabler system, has a switching device with which it can be deactivated so as to prevent delivery of he current to vehicles that pass over the road surface (i.e., driving surface) that are not to be disabler. 
     The use of alternating current power lines, as are commonly known in the art, e.g., 220/110 volt alternating current lines, eliminates the need to provide for replacement or recharging of the battery that may be used with the man-portable electromagnetic vehicle disabler system. The permanently-installed electromagnetic vehicle disabler system can, however, utilize such a battery as a backup power source, e.g., in the event the power supplied by the alternating current land lines is interrupted. 
     The permanently-installed electromagnetic vehicle disabler system may be used in environments where such a permanent installation is desirable. For example, the permanently-installed electromagnetic vehicle disabler may be installed at toll gates, or border crossings, where in the event the vehicle  10  attempts to “run” the toll gate or border gate, the vehicle  10  can be arrested (stopped) by an officer activating the switching device of the electromagnetic vehicle disabler system. 
     In contrast, the man-portable electromagnetic vehicle disabler of FIGS. 2 and 3 is desirable in environments where vehicle disabler is not normally needed, such as might be the case if a temporary police check point or road block were established. 
     In the event the man-portable electromagnetic vehicle disabler system is used to arrest vehicles, in lieu of conventional police roadblocks using wooden barricades, police mobile units, or the like, a remote transmitter  40  may be used to transmit a trigger signal  42 , which toggles the switching device  23  within the charge supply unit  30  on or off. In this way, a police officer can manually toggle the man-portable electromagnetic vehicle disabler system on or off so that only vehicles that are to be disabler will be subjected to the current—when the current supply unit  38  is toggled on—whereas vehicles that, for example, the police officer wants to let pass the electromagnetic vehicle disabler will not be subjected to the current—when the current supply unit  38  is toggled off. In a simplified embodiment, the switching device of the current supply unit  38  is a conventional SPST power toggle switch, that can be switched on or off by a user, e.g., the police officer. 
     Referring next to FIG. 5, a side view is shown of a vehicle-mounted electromagnetic vehicle disabler system having a pair of electrically conductive wires  46 ,  48  that are deployed from a pursuing vehicle  50  (or mobile unit) against a pursued vehicle  52  (i.e., the vehicle  10  of FIG. 1) so as to put the pursued vehicle  52  in electrical communication with the electrically conductive wires  46 ,  48 . 
     The electrically conductive wires  46 ,  48  are deployed against the pursued vehicle  52  from a launcher  54 , which may utilize pressurized air, chemical explosive force, e.g., gunpowder, spring force, or the like to propel the electrically conductive wires  46 ,  48  against the pursued vehicle  52 . The electrically conductive wires  46 ,  48  remain affixed, at a proximal end of the electrically conductive wires  46 ,  48 , to respective points near the launcher  45 . The points are electrically coupled to the current supply unit  38 , which is housed within the pursing vehicle&#39;s engine compartment (not shown in FIG.  5 ). Distal ends of the electrically conductive wires  46 ,  48  are fitted with fasteners  55 , such as suction cups, magnets, or other highly adhesive devices or materials that readily adhere to the surface, e.g., the rear decklid and/or bumper, of the pursued vehicle  52 . The fasteners  55  also serve to weight the distal ends of the electrically conductive wires  46 ,  48  so as to facilitate their propulsion toward the pursued vehicle. 
     Thus, when the electrically conductive wires  46 ,  48  are propelled by the launcher  54  against the pursued vehicle  52 , the fasteners  55  at the distal ends thereof are propelled toward the pursed vehicle and mechanically adhere to part of, e.g., the rear decklid of, the pursued vehicle  52 . Such mechanical adherence causes an electrical connection between the electrically conductive wires  46 ,  48  and the pursued vehicle  52 , and allows the current (from the current supply unit) to flow from one of the electrically conductive wires  46 , through the pursued vehicle  52 , to another of the electrically conductive wires  48 . Such current causes the disabling or inhibiting of the pursued vehicle&#39;s power source, as described hereinabove. In this way, the pursued vehicle  52  is disabler by the pursuing vehicle  50 . 
     Referring next to FIG. 6, a side view is shown of a vehicle-mounted electromagnetic vehicle disabler system having a pair of electrically conductive fluid streams  60 ,  62  that are discharged from a pursuing vehicle  50  against a pursued vehicle  52  so as to put the pursued vehicle  52  in electrical communication with the electrically conductive fluid streams  60 ,  62 . 
     The electrically conductive fluid streams  46 ,  48  are discharged against the pursued vehicle  52  from first and second nozzles  60 ,  62 , which may utilize pressurized air or the like to propel the electrically conductive fluid streams  56 ,  58  against the pursued vehicle  52 . The electrically conductive fluid streams  56 ,  58  are discharged through the nozzles  60 ,  62  from reservoirs (not shown) within the pursuing vehicle  50 . The reservoirs are in electrical communication with the current supply unit  38  (not shown in FIG. 6) and supply the current to the electrically conductive fluid streams  56 ,  58 . 
     Thus, when the electrically conductive fluid streams  56 ,  58  are discharged by the nozzles  60 ,  62  against the pursued vehicle  52 , and an electrical connection is made between the electrically conductive fluid streams  56 ,  58  and the pursued vehicle  52 , such connection allows the current (from the current supply unit  38 ) to flow from one of the electrically conductive fluid streams  56 , through the pursued vehicle  52 , to another of the electrically conductive fluid streams  58 . As a result, the power source of the pursued vehicle is disabled or inhibited as described hereinabove, thereby disabler the pursued vehicle. 
     Alternatively, the electrically conductive fluid streams  56  may project from a driving surface, instead of from the pursuing vehicle  50 , so as to be in electrical communication with the pursued vehicle  52  when the pursued vehicle  52  drives over the driving surface. 
     Referring next to FIG. 7, a side view is shown of a vehicle-mounted electromagnetic vehicle disabler system having a single electrically conductive wire  46  that is deployed from the pursuing vehicle  50  against the pursued vehicle  52  so as to put the pursued vehicle  42  in electrical communication with the electrically conductive wire  46 . 
     The single electrically conductive wire  46  is deployed against the pursued vehicle  52  from the launcher  54 , as described hereinabove. The electrically conductive wire  46  remains affixed, at a proximal end of the electrically conductive wire  46 , to a point near the launcher  45 . The point is coupled to the current supply unit  38  (not shown in FIG.  5 ). As described above, a distal end of the electrically conductive wire  46  is fitted with a fastener  55  of the pursued vehicle  52 . 
     When the electrically conductive wire  46  and the fastener  55  are propelled by the launcher  54  against the pursued vehicle  52 , the fastener  55  at the distal end thereof mechanically adheres to the pursued vehicle  52 . Such mechanical adherence causes the electrical connection between the electrically conductive wire  46  and the pursued vehicle  52 , and allows a high frequency alternating current (from the current supply unit  38 ) to flow from the electrically conductive wire  46 , through the pursued vehicle  52 , to earth ground. Such flow to earth ground may be through the pursued vehicle&#39;s tires, with coupling between the pursued vehicle and earth ground being facilitated by the high frequency of the alternating current. 
     The charge supply unit  38  within the pursing vehicle  50  is coupled to earth ground using a grounding wire  70  that drags along the road surface  32 , thereby placing the pursing vehicle  50  into electrical communication with the road surface  32 , i.e. earth ground. The grounding wire  70  is affixed to the underside of the pursing vehicle at a substantially normal angle relative thereto, but is not grounded to, i.e., electrically connected to, the underside of the pursing vehicle  50 . Instead an insulated grounding cable (not shown within the pursuing vehicle  50 ) passes return current from the grounding wire  70  to the current supply unit  38 . The grounding wire  70  bends so as to contact the road surface  32  substantially parallel thereto. Mechanical contact between the grounding wire  70  and the road surface  32 , i.e., earth ground, is facilitated by spring force, which arises due to the bending of the grounding wire  70 . 
     When the current is passed through the electrically conductive wire  46  to the pursed vehicle  52 , and back through earth ground to the current supply unit  38 , the power source of the pursed vehicle is disabled or inhibited, thereby disabler the pursued vehicle. 
     Referring next to FIG. 8, a side view is shown of a vehicle-mounted electromagnetic vehicle disabler system having a single electrically conductive fluid stream  56  that is discharged from a pursuing vehicle  50  against a pursued vehicle  52  so as to put the pursued vehicle  52  in electrical communication with the electrically conductive fluid stream  56 . 
     The single electrically conductive fluid stream  56  is deployed against the pursued vehicle  52  from the nozzle  60 , described hereinabove. The electrically conductive fluid stream  56  is discharged through the nozzle  60  from the reservoir (not shown) within the pursuing vehicle  50  and the reservoir is in electrical communication with the current supply unit  38  (not shown in FIG.  6 ). 
     When the electrically conductive fluid stream  46  is discharged by the nozzle  60  against the pursued vehicle  52 , an electrical connection is made between the electrically conductive fluid stream  46  and the pursued vehicle  52 , which allows a high frequency alternating current (from the current supply unit  38 ) to flow from the electrically conductive fluid stream  46 , through the pursued vehicle  52 , to earth ground. Such flow is facilitated by the high frequency of the current, because such high frequency facilitates the coupling of the current through, e.g., the pursued vehicle&#39;s tires, as described hereinabove. 
     The charge supply unit  38  within the pursing vehicle  50  is coupled to earth ground using the grounding wire  70  that drags along the road surface  32 , thereby placing the pursing vehicle  50  into electrical communication with the road surface  32 , i.e. earth ground. In this way, the pursued vehicle  52  is disabler by the pursuing vehicle  50 . 
     The use of electrically conductive fluid streams to establish electrical communication is described in copending patent application Ser. No. 08/273,571, filed concurrently herewith, entitled Portable Electronic Stun Device and Method, which application is assigned to the same assignee as the present application and is incorporated herein by reference. 
     While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.