Butterfly sword?

[ARADOX]

I always thought that the butterfly swords (or bulls ear sword whatever you wanna call them) were more of a Chinese variant of a Japanese weapon called a "Jitte" if you look it has the sword catching bar thing on the back, the only difference is that it's sharp, I wonder what kond of people actually used these, it looks too, sort of, proffesional if you like to be a street weapon, but it's not really big or heavy enough to be an effective military weapon, perhaps an assassins toy, oooooohh , nice stuff, if anyone uses these I'd like to know more about the actual techniques and see if they ARE assassin-like.

http://www.trocadero.com/noamin/items/630284/en1.html

I believe Jitte were a blunt with a pointed tip for thrusting. The prong that ran up was used for catching a sword and twisting it out of somebody's hands, or in the hands of a skilled practitioner, even break them.

http://www.wle.com//products/w104c.html

Butterfly knives were are essentially heavy, single-edged knives that were for the most part chisel sharp. I believe the prong on a butterfly knife can be used the same way as the jitte. They are much heavier than a jitte so techniques would be completely different. Butterfly knives are also used for strength training.

Strength training?, yeah that's interesting, I am still at a loss to know what these things were actually usd for as i've said they really aren't big enough to make for effective military weapons, but the jitte was always a police weapon, and the butterfly knives are WAY more lethal that a jitte, so probably not a law enforcement weapon, they don't really strike me as very heavy though, perhaps they may have been used by the law enforcement as a deterent or a threatening weapon much the same as the old English policemen carrying sabres?