Reach Out and Zap Someone: The Patent History of Electric Stun Weapons
Zaap…zaaap-clack-clack-clack…zaaap. Just the sound and spark of an electric weapon triggers something from childhood that makes you step back when you see and hear the electricity arc through the air between the leads. The two most common forms of today’s electric “stun” technology, both of which can take advantage of that reaction, are the stun gun and the taser. [N1]. The early antecedents of both of these devices can be found in the records of the United States Patent Office and a review of the patent record shows that the development of electroshock devices was first aimed at incapacitating animals before later being extended to humans.
Development of the Stun Gun
Electricity was written about as early as 6oo B.C.E. when philosopher Thales of Miletus found that amber, after being rubbed by wool, would attract feathers, thereby resulting in a practical demonstration of static electricity. By 46 C.E., Roman physician Scribonus Largus introduced the electrical powers of fish into clinical medicine as a cure for headache and gout. However, it was not until electricity was first “bottled” in the 18th century that large numbers of electrical experiments (and mistakes) with humans and animals arose.
One of the earliest experimenters, Petrus Musschenbroek, is a candidate for discoverer of the Leyden jar (he was from Leiden, Netherlands), which is a device used to store static electricity by separating differently charged ions. It behaves similarly to a capacitor in that it stores a built-up charge and releases it quickly. When touching the wrong part of a charged Leyden jar in 1746, and consequently completing a circuit, Musschenbroek may have been the first to experience what countless electricians, unsupervised children, and stun-gunned subjects would eventually experience in more recent centuries: “Suddenly I received in my right hand a shock of such violence that my whole body was shaken as by a lightning stroke…the arm and body were affected in a manner more terrible than I can express. In a word, I believed that I was done for.” Musschenbroek had just received a really strong electrical shock, one of the first man-made electrical discharges powerful enough to be frightening. Even more fascinating is that the charge was created purely through static electricity: typically, a large wool pad was spun on a glass globe to store a charge inside a connected Leyden jar.
Musschenbroek’s discovery led to the first crude stun guns: the same century a number of European demonstrators with charged Leyden jars ran around killing birds and other animals under the guise of “scientific demonstrations.” Except for proof of lethal effect, these demonstrations added little to the body of knowledge regarding the interaction of animals and electricity. However, in a series of experiments starting around 1780, Luigi Galvani, at the University of Bologna, found that the electric current delivered by a Leyden jar or a rotating static electricity generator would cause the contraction of muscles in the legs of dead frogs and other animals when applied to the muscle or to the nerve. The following illustration shows, among other things, frog legs with leads attached on the left, a static electricity generator middle left, and a Leyden jar on the far right.
Whereas Musschenbroek’s experiments led the way in showing that pain and possibly death could result from exposure to electricity, Galvani’s frog experiments became the basis to later show that nerves could be directly stimulated, and eventually to show that electricity could be used to incapacitate humans.
In the meantime, the manual generation of electricity was limited to static electricity generators until Michael Faraday invented the dynamo in 1831. In a dynamo, electromotive force is developed in a conductor when it is moved through a magnetic field. Of course, a hand-cranked dynamo hardly leads to the development of a practical handheld self-defense device. For that, the development of a practical battery was required. In 1800, Alessandro Volta had created the first chemical battery, a voltic pile constructed of different metals and brine. Even so, the first commercially viable battery design was not produced until 1886, when Carl Gassner patented the carbon-zinc dry cell. Gassner’s basic concept is still used in many modern batteries.
Once all the elements were in place, it was only a short time before the first electrical shock device was developed. In 1890, inventor John Burton, of Wichita, Kansas, patented the “Electric Prod Pole,” or electric cattle prod. Burton envisioned the device as helping direct cattle without piercing the valuable hides like common non-electric cattle prods.
The patent had two basic designs, one powered by battery (Figure 1) and one by an internal dynamo (Figure 2). The design is simple, but the important elements are already in place. In Figure 1, the prod is simply a battery, a coil of wound wire, and two positive and negative prongs. A battery by itself would have too little voltage to overcome the non-conductivity of an animal’s hide (resistance). It appears that the coil would act to step up the voltage enough so that the current could flow through an animal’s hide and cause a localized shock. In 1915, a patent was issued for a similar battery operated design that appeared to do little more than provide a new method to hold the cap on and add an on/off switch (an important safety feature).
Burton’s dynamo design, on the other hand, produced its own electricity by pushing the prod against the animal, which collapsed the handle a short distance. Doing so would then activate the ratchets at F and G (Figure 2) causing the S-prime shaft to rotate. The shaft rotated the armature through the magnets N and S, creating a current. It seems unlikely that the dynamo, through such a meager application of mechanical movement, could create enough current to cause the desired effect, especially without a coil such as used in Figure 1 to step up the voltage to overcome the resistance of the animal’s hide.
In 1939, Hansen and Cough had patented a prod with only superficial differences from earlier battery-powered designs, the main difference being an extension that could be added to the end of the prod to better reach cattle in a pen. Then in July 1940, Leon Paul Mongan patented a combination flashlight/cattle prod for those moving cattle before daybreak or after dusk. Internally, the battery-operated device sent current to a vibrator that converted the direct current (DC) to alternating current (AC). The current was then stepped up through a transformer to high voltage AC and went to the terminal contact points. A capacitor limited the amount of arcing between the contacts. The contacts, partially retractable, completed the circuit when pressed against an animal. The previous month, Ernest Jefferson had also obtained a patent for a safer prod with a pair of spring tension terminals that had to be pushed in against the hide of the animal for the device to operate.
Due to refinements through the years, the 1940s cattle prods began taking an internal form similar to modern stun guns. Not only were the internals similar, but some models even outwardly resembled modern stun batons.
However, it was well before the 1940s when inventions began to appear that applied electroshock technology to humans. By 1912, the idea of using a portable electric device for self-defense and law enforcement had appeared. In an amazing, as well as an amazingly hazardous, invention, Jeremiah Creedon of Philadelphia, Pennsylvania patented a set of “Electric Gloves” to be used in “subduing unruly persons” and “resisting attacks.” The device consisted of a pair of gloves with leads connected by wires to a belt on which a battery and an induction coil were mounted. While the method of application differed, the design was basically the same as used in the cattle prod. In either design, the relatively low voltage (compared to modern stun guns) means that the effect would probably be limited to localized pain where the contacts touched the subject, rather than incapacitation.
German inventor Franz Lollert came up with a similar device in 1926, although slightly less cumbersome. He hoped it would “give to every person carrying something equivalent to a training in jiu-jitsu.” Notably, Lollert supposedly had a demonstration model that he used with some success. He even had interest from the German police in purchasing the device.
An almost identical device was patented in 1933 that added another coil and substituted a different design for the contacts in the gloves. Its appearance was very similar to the original 1912 device and the inventor, like Lollert before him, was active in marketing the device to police forces. Cirilo Hernandez Diaz was a Cuban inventor who worked in Latin America as a construction superintendent for an American company. He used the induction coil from a Model T Ford to step up the voltage to around 1,500 volts and reduce the amperage to a level that would not burn anyone touched by the gloves.
While most of the previous devices included an induction coil, Diaz was the first to articulate an important safety and efficacy principle behind electric stun weaponry: the need to increase the voltage and reduce the amperage from the battery source. High voltage passes through poorer conductors, such as hide, skin, or clothing, better than low voltage. If the power source remains the same, stepping up the voltage will also reduce the amperage produced, which is an important point, since most adults will go into ventricular fibrillation at currents around .1 amperes.
Diaz pitched the gloves as a method to quell rioters and subdue individuals resisting arrest. After a demonstration to the New York City police in 1935, Diaz then demonstrated the device to reporters by “subduing unsuspecting entrants to the office of the inventor.” (New York Times, June 23, 1935). No mention was made whether any of the surprise subjects later punched the inventor in the nose. According to Diaz, then deputy police commissioner Martin Meany requested a price quotation on quantities of the device. If the procurement was ever made, it doesn’t appear that the use of the gloves by the police ever became widespread.
While the designs were moving in the right direction by the 1940s, it took the development of the taser in the late 1960s/early 1970s to spawn commercial sales of the handheld stun gun. In the meantime, law enforcement adopted cattle prods for use during the early 1960s civil rights protests. In conjunction with fire hoses and wooden batons, law enforcement utilized cattle prods to painfully shock protesters and suppress marches. The similarity between stun batons and cattle prods has led many critics to decry any law enforcement use of stun batons as an attack with cattle prods. Considering the shared development history, such charges may be wrong in fact, but not in principle: stun guns and cattle prods are a question of differing voltages more than any other factors. The low voltage of the prod is intended to cause localized pain, whereas the higher voltage of the stun gun is intended to overwhelm the human nervous system and cause temporary incapacitation.
That flurry of activity in the 1970s brought a resurgence of interest in wearable devices such as the electric gloves. A 1982 patent was issued for a lightweight harness worn on the hand that allowed current to flow through contacts located at the end of the index finger. It was probably just a coincidence that E.T.: The Extra-Terrestrial was also released in 1982, because the patent application was made in the late 1970s.
Another electric glove was patented in 1983, then in 1992 came a terrifying set of electric trousers or chaps designed to discourage livestock from crowding human feeders. This in turn led to a November 2005 patent for a women’s electric jacket. The jacket has on/off controls in the sleeve and, once activated, a visible electric arc on the shoulder to scare off aggressors. The inventors are cognizant of the devices weaknesses, warning against activating the device in wet conditions as well as the danger of exposing non-insulated body parts to it, such as the legs or head. [N3]. Those warnings are clearly ones that could be applied to all the wearable devices generally. Considering the patent history of these devices, it is interesting that the electric jacket inventors recommend against using the jacket for protection against animals because of their different physiology. Of course, an electric jacket only seems half-suited for defense against most animals anyway, being a passive device with large gaps in coverage and vulnerable to puncture
Development of Projectile Stun Devices
Another weakness of both handheld stun guns and wearable devices is obviously one of range. The user must not only gain contact with the subject, but must remain in contact for a few seconds for full effect. If the subject is armed, larger, stronger, or even just sufficiently motivated, the user could still sustain injury. The TASER attempted to solve that problem by delivering a charge to subjects several body lengths away. The T.A.S.E.R. name is an acronym derived from the fictional Thomas A. Swift Electric Rifle. The inventor, John H. (“Jack”) Cover, is generally described as a former physicist or engineer that worked on the Apollo space program. In the late 1960s, Cover began development of a non-lethal projectile method of subject apprehension. By the mid 1970s, Cover had developed the TASER, a device that fired projectiles from a handheld device using gunpowder as a propellant. The barbed projectiles were designed to attach to a subject’s clothing or penetrate the skin. Two wires trailed from the device to the projectiles and delivered 50,000 volts of electricity to the subject. Although the device was shown being used in the 1976 Clint Eastwood film “The Enforcer,” the taser proved difficult to market; gunpowder propellants meant the device was strictly regulated as a firearm.
Cover’s experiments continued and his subsequent development of a compressed nitrogen gas propellant allowed for greater marketability. However, because of some well-advertised failures of the device (think of the 1991 beating of Rodney King, where King was able to remove the attached wires) commercial success for the Cover design remained elusive. The failure rate against motivated and/or drugged subjects remained high. It was not until 1994 that the first commercial success was achieved with the development of an improved taser version by Taser International, Inc. In the ensuing years, and particularly after refinements made in 1999, Taser International, Inc. sold hundreds of thousands of tasers worldwide. That success has led to criticism from groups such as Amnesty International regarding the safety record of the taser. Another area of contention has been sales of the taser to countries known to practice torture. Electroshock devices have long been favored as instruments of torture because they can cause excruciating pain and do not leave marks on the victims. [N2].
In the original taser patent application, Cover references a number of previous patents that led to his invention. Again, these early patents are aimed at incapacitating animals rather than humans. One interesting device, and the oldest of those listed, is an 1852 patent for an electric whaling harpoon. The principle is similar to that of the taser: a power source is connected by a conducting wire to a barbed electrode that sticks into the subject. Of course, this is well before a mass-produced battery was developed, so the electricity was generated by a hand-cranked dynamo. Another difference is that only a single electrode and wire was used, so the bottom of the boat was covered with copper for the return current to flow back through the water. The inventor, Christian Heineken of Bremen, Germany, planned to manufacture electric harpoons and dynamos in Baltimore, Maryland, but the device never took off commercially. As if whaling was not a dangerous enough profession to begin with, the mixture of a strong electrical source, an electrocuted whale, and the high seas could not have been very safe.
Apparently most whalers agreed that the device was either too dangerous or just unworkable. The electric harpoon had been tested on the Bremen whaleship Averick Heneken in 1851 and possibly the Amethyst out of New Bedford in 1854-59, but Heineken’s device never found favor with whalers. The New Bedford Whaling Museum possesses what it believes may be the only electric Heneken harpoon to survive.
By the 1860s, the explosive harpoon came into use and is still used in modern whaling. Electric wires inside whaling lines were tried in the 20th century, but they were used to trigger the explosive harpoon rather than electrocution. However, Japan does use electric lances today, in addition to rifles, to kill whales that have been harpooned.
Cover also referenced a 1957 Thomas D. Ryan patent covering a handful of projectile weapons that carried an electroshock device within the projectiles’ heads. Shown below, from left to right, are an arrow, a lance, a fencing foil, and a spear.
The electroshock mechanism in these is the simplest of designs, hearkening back to the earliest devices: there is a battery source, a coil, an arming switch and the two electrodes embedded in the bladed portions of the weapons. Ryan’s patent application, submitted in the midst of the Cold War, shows a certain 007 flavor: in Ryan’s opinion, these inventions would be perfect for modern warfare’s “commando-type attacks” where stealth and surprise were paramount considerations. A secondary application was in allowing hunters a way to quickly drop their prey even if struck a non-mortal injury with the projectile. The fencing foil shown is described as a piercing weapon, so the intent appears to be for combative use of the foil rather than in simply electrifying a training or sporting weapon. In contrast, at least one manufacturer today is offering an electrified training knife to increase the realism, or at least the concentration level, of training knife sparring. [N4].
As can be seen, many of the fundamental concepts behind the taser were in existence long before the device came about. The commercial development of the taser led the way for the current market glut on personal electroshock devices. The patent field relating to stun weaponry aimed at human subjects expanded rapidly in the 1960s and continues to develop at a furious rate today. In addition to the large number of handheld stun guns currently available, the taser now faces competition from at least one other manufacturer of a similar projectile electroshock device. General electroshock devices are so popular today that a current fad is the “taser parties” taking the place of yesterday’s “tupperware parties.”
Patent records also show a number of different designs for less-lethal electrical-based weaponry that may one day lead to the development of devices based on different technologies, such as electrical devices using liquid, liquid metal, or laser discharge as conduction media, bullets containing charges or gaining charges in flight through piezoelectric action, and too many other methods to address here. If the patent history has shown anything, it is clear that the future will hold new and interesting methods of zapping both people and animals.
N1. TASER is a registered trademark of Taser International, Inc.
N2. For a history of electric torture devices, see Electricity: The Global History of a Torture Technology by Darius Rejali at http://academic.reed.edu/poli_sci/faculty/rejali/rejali/articles/History_of_Electric_Torture.htm
N3. For more on the device, see http://www.no-contact.com/
N4. Official marketing for the “Shock Knife” appears to focus more on law enforcement than martial arts applications: http://www.shocknife.com/index.html. However, the shocknife is certainly being introduced into the martial arts world; the Dog Brothers use them for their knife sparring and this author was recently able to experience one at a martial arts seminar. My take is that the sound and sight is intimidating when triggered, and it does feels a bit like being cut as it is drawn across the skin, but it is not particularly painful.