Patent No. 5952600 Engine disabling weapon

 

Patent No. 5952600

Engine disabling weapon (Herr, Sep 14, 1999)

Abstract

A non-lethal weapon for disabling an engine such as that of a fleeing car by means of a high voltage discharge that perturbs or destroys the electrical circuits. The transmission of the disabling voltage to the distant target is via two channels of electrically conductive air. The conductive channels are created by multi-photon and collisional ionization within the paths of two beams of coherent (laser) or collimated incoherent ultraviolet radiation directed to the target. A single beam may be used when the high voltage source and the target are grounded. The high-voltage current flows from electrodes at the origin of the beams along the channels of free electrons within them.

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SUMMARY OF THE INVENTION

The principal object of the instant invention is to provide a non-lethal immobilizing weapon for use by military or law enforcement personnel.

A second object of this invention is to provide a non-lethal, immobilizing weapon which is inherently safe in its operation.

A third object of this invention is to provide a non-lethal weapon which is capable of temporarily immobilizing a target subject without causing pain, shock, disorientation, or loss of consciousness.

A fourth object of this invention is to provide a non-lethal weapon which is capable of temporarily immobilizing a target subject without his being aware of the cause.

A fifth object is to provide a non-lethal, immobilizing weapon whose range is substantially greater than prior related weapons that use wires or conductive liquid streams.

A sixth object is to provide a non-lethal, immobilizing weapon which can be fired from a remote location without requiring the physical impact of solid or liquid matter upon the target.

A seventh object is to provide a non-lethal, immobilizing weapon which can be directed continuously and swept across an indefinitely large number of target subjects.

An eighth object is to provide a non-lethal, immobilizing weapon which can rapidly be fired toward a specific location on a single target subject, or to a specific target subject among many because of the highly directional nature of its current-conducting means.

A ninth object is to provide a non-lethal, immobilizing weapon which has a significantly longer service life than prior related weapons.

These and other objects are achieved by transmitting relatively high frequency electrical impulses to the target by means of one or two electrically conductive channels of ionized air produced within one or two beams of intense ultraviolet radiation aimed at the target, and by placing a high-voltage field of the opposite polarity across the path of each beam.

The present invention functions by immobilizing the target person or animal at a distance. It performs this function by producing skeletal muscle tetanization in the target subject. Tetanization is the stimulation of muscle tissue by a series of electrical impulses of such frequency as to merge individual muscle contractions into a single sustained contraction. The immobilizing tetanization is maintained as long as the weapon continues to produce an electrical current within a major portion of the skeletal musculature of the subject, and for a brief time thereafter due to paralysis caused by the temporary inhibition of neuromuscular impulses. The optimum current and frequency required to create and maintain immobility while avoiding impairment of cardiac or respiratory activity are 25 milliamperes and 100 hertz, respectively. Currents in the range of 20 to 50 milliamperes and 1 to 10,000 hertz may also be employed, with the higher frequencies requiring higher currents. A frequency of about 2 hertz may ultimately be used to produce painful spastic contractions. A minimum electrical potential of approximately 600 volts is required to overcome skin resistance without producing burns.

The most effective current waveform in producing tetanization is that which most closely duplicates the physiologically produced neural impulse. As Offner points out, this waveform is an exponentially rising pulse. The second most effective waveform is a square wave, whereas the least effective is a sine wave. Due to their rapid rise-times, square waves allow the greatest penetration through the clothing and skin of the target subject.

Further, the differences in the effectiveness of various waveforms constitute an inherent safety factor in the operation of the instant weapon. This safety factor is a result of the rapid absorption by biological tissue of the harmonic frequencies within complex waveforms such as square waves. A 20 to 50 milliampere current is thus able to stimulate only the target subject's skeletal muscles, and cannot penetrate to the autonomically-controlled internal muscles such as the heart.

A lethal variation of the present weapon could be implemented by increasing the current above approximately 250 milliamperes. A sine wave current having a density of about 5 milliamperes per square centimeter that flows through cardiac muscle for more than about two seconds may initiate ventricular fibrillation. The duration of the current needed to cause ventricular fibrillation is inversely proportional to the current density within the cardiac muscle.

The current carried by the ionized air channel is limited by the number of free electrons within the ultraviolet beam. A minimum 20 milliampere current required to induce skeletal muscular tetanization can be carried by a gaseous channel with a concentration of 10.sup.8 ions per cubic centimeter. This concentration is most efficiently achieved in air by ionizing molecular oxygen with coherent or collimated incoherent ultraviolet radiation having a wavelength of approximately 193 nanometers. Shorter wavelengths may be employed as optical technology progresses.

At its normal operating intensity and a wavelength near 193 nanometers, the ultraviolet beam is safe to the skin because it cannot produce more than mild erythema akin to a sunburn unless it is directed at the same location for many minutes. Moreover, it is safe to the eyes because wavelengths near 193 nanometers cannot penetrate the cornea to reach internal ocular structures such as the lens and retina.

At this wavelength, molecular oxygen has a two-photon ionization cross section of 1.times.10.sup.-34 cm.sup.4 /watt. Because of its low ionization threshold, the number of photons required for ionization, and its large proportion in the atmosphere, it is easily able to create sufficient electron density.

The most efficient source of 193-nanometer radiation presently available is the argon fluoride discharge-pumped excimer laser. A reasonable power density, pulse duration, and pulse repetition rate for this laser is 5 megawatts per square centimeter, 10 nanoseconds, and 200 pulses per second, respectively.

An argon fluoride laser with an aperture of 1 square centimeter has a power density (energy output) of 10 millijoules per pulse or 1 megawatt per square centimeter. Each pulse liberates 6.3.times.10.sup.6 electrons, or 6.3.times.10.sup.14 electrons per second in the air immediately outside the aperture. A power density of 50 millijoules per pulse or 5 megawatts per square centimeter liberates 1.6.times.10.sup.8 electrons during each pulse, which is equivalent to 1.6.times.10.sup.16 electrons per second.

A narrow beam of ultraviolet radiation may also be generated from the collimated emission of an ultraviolet lamp.

The electron density in the channel of ionized air is a function of the ratio between the electron production and loss rates. In both the two-body and three-body electron attachment processes, the delay time between the end of the laser pulse and the beginning of the high-voltage tetanizing pulse determines the number of available electrons. When the electron energy is only 0.1 electron volt, for example, the three-body attachment is rapid, and the steady-state electron density for a 193 nanometer, 5 megawatt per square centimeter beam falls to 8.times.10.sup.7 per cubic centimeter.

The range of the present weapon is determined by the rate at which the laser beam is absorbed by the atmosphere. A 193-nanometer wavelength beam is attenuated in dry air at about 1.times.10.sup.-4 per centimeter. It will thus propagate approximately 100 meters before its intensity is decreased to l/e of its initial value. As a consequence, the 1.6.times.10.sup.8 electron density at the aperture of an argon fluoride laser with a power density of 5 megawatts per square centimeter falls to 2.2.times.10.sup.7 after 100 meters. Because the minimum electron density required to transmit a current is between 10.sup.6 and 10.sup.8 per cubic centimeter, the above ionized channel should conduct the tetanizing current at least 100 meters. The range of this weapon could be increased, however, by the use of a more efficient ultraviolet source.

Various techniques, including those suggested in U.S. Pat. No. 4,017,767 Ball and U.S. Pat. No. 5,175,664, Diels et al. which are incorporated herein by reference, may be used in order to enhance the multi-photon and collisional ionization along the laser beams. These techniques are well known to persons skilled in the electrical arts.

The engine-disabling application of the invention creates high voltage discharge in the proximity of a vehicle engine either by using the vehicle body as a shorting means between either voltage-carrying beam and the ground or a pair of voltage-carrying beams.

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While the preferred embodiments of the invention have been described, modifications can be made and other embodiments may be devised without departing from the spirit of the invention and the scope of the appended claims.