Taser International makes much of the fact that the taser darts "...are propelled by compressed nitrogen gas..."
The question raised is: What mechanism opens the little gas canister?
I'd always assumed that a clever designer would have found a way to arrange a very simple hollow-tipped puncturing mechanism, operated by the force of the trigger pull. But 'Critical Mass' was convinced that the canister was opened with a small explosive charge, like a detonating cap.
If it is a detonating explosive cap, then Taser International appears to have a policy of not highlighting it.
Well, there's a warning that the cartridges are sensitive to static shock.
Fair Use / Fair Dealing claimedWhat would be potentially sensitive to static electricity except a small percusive cap?
I'm still open minded on the mechanism used, but I want to make sure that this question is raised publically.
If anyone has a clear and definitive answer, please send it in. Blog e-mail address is in the right column.
3 comments:
Thanks for putting the issue of "explosive nitrogen gas release" in taser cartrdges, on the more visible pat of your Blog.
In paintball guns, the compressed air/CO2 or nitrogen gas, comes at 3000 to 5000 psi. and is valved down to a much lower psi. value to propel the paint-balls at safe velocities. There is plenty of room on the paintball gun to have both large gas canisters, mechanical puncture/gas release mechanisms and pressure reducing valves. Not so in the taser cartridge :
"compressed air or nitrogen is stored in the tank at a very high pressure, typically 3000-5000 psi."
http://en.wikipedia.org/wiki/Paintball_marker#Carbon_dioxide
To "puncture" a nitrogen gas cartridge with a pressure of 3000 psi. or greater, a very substantial push would be required to release the gas. The cartridge walls have to be fairly substantial, even at a pre-determined "puncture wall", to contain those psi. values of 3000 to 5000 psi. for nitrogen gas. There is simply no room in the taser cartridge to mechanically drive the nitrogen cartridge against a puncture point. It almost certainly is a small percussive cap, much like the "blank" in a starter's gun.
There are stun guns on the market which simply use an explosive ("gun powder") charge to propel the darts, but their sale is restricted to law enforcement and can not be sold to the public, as Tasers are, due to ATF restrictions. Taser International wanted their device to be sold to the public, so they claim their cartridge only uses a nitrogen charge.
I strongly suspect that the manufacturer of the most widely used stun gun in the USA (the "Taser") has quietly been using ATF controlled and regulated materials in its cartridges, possibly in contravention of ATF Regulations.
It makes sense to use the on-board battery in a taser, to generate a static electrical charge to ignite the percussive cap. There is no room, again, for a "firing pin".
That is why taser cartridges need to be kept away from static electricity, even when they are not loaded in the taser pistol. There almost certainly is a percussive cap inside which could be discharged by a static spark.
I just noticed that "Dr." Charles Mesloh at Florida Gulf Coast University has secured an off-campus "testing facility" for his favorite non/less-lethal police weapons:
http://www.naplesnews.com/news/2009/oct/11/fgcu-professor-now-has-room-shoot-test-his-less-le/
Charlie has been a fairly consistent "Taser Spokes Boy", after his "permanent disability retirement" from the Venice CA Police Department and his move to Florida, where he and his wife have a small business that promotes accessories for some of the non-lethal products Charlie bases his academic career on.
Perhaps Charlie could tell us what releases the nitrogen gas in the taser cartridge?
I'm no fan of Charlie, as you may divine, but an email to him might help solve the question.
The following is taken from a Patent Application for a compressed gas cartridge puncture mechanism. Of the 10+ methods discussed, only 2 employ an explosive charge. All other gas release mechanisms are the cumbersome "spring-loaded" type, which involve arming the spring manually. The only compact and instant gas release is achieved with small, explosive charges.
http://www.wipo.int/pctdb/en/wo.jsp?IA=US2005016657&DISPLAY=DESC
Quote:"FIG. 7 depicts a simplified cross-sectional view of a puncture mechanism 400 according to some embodiments. The puncture mechanism 400 includes an explosive material 401 , a compressed gas cartridge 402 and a puncture pin 403 housed in and/or coupled with a frame 404. The explosive material 401 can include a primer, gun powder, blank load or other type of chemically explosive material and/or combinations of materials that generate an explosive force upon activation or ignition. The explosive material 401 is [what] drives the compressed gas cartridge 402 into the fixed puncture pin 403 upon ignition or activation of the material such that the cartridge is punctured quickly releasing the gas. The primer or gunpowder can be ignited by conventional means, such as through striking with a hammer or other object, electrical ignition and other methods.
FIG. 8 depicts a simplified cross-section view of an alter[n]ative gas cartridge puncture mechanism 500 according to some embodiments. The puncture mechanism includes an explosive material 501, a puncture pin 502, a compressed gas cartridge 503 housed in and/or coupled with a frame 504. The explosive material 401 can include a primer, gun powder, blank load or other type of chemically explosive material and/or combinations of materials that generate an explosive force upon activation or ignition. Upon ignition or activation of the explosive material, a chemical explosion is used to drive a puncture pin 502 into the fixed compressed gas cartridge 503 quickly releasing gas. The primer or gunpowder could be ignited by conventional means, such as through striking with a hammer or other object, electrical ignition and other methods."
I think the difference between the above two "explosive gas release mechanisms" is whether the gas cartridge is driven against a puncture pin, or the puncture pin is driven against the gas cartridge.
There is simply no "compact, instant, compressed gas release mechanism" of a mechanical type. The more I read, the more convinced I am that the taser cartridge uses a compact explosive charge.
Post a Comment