Two-Stage Hidden Blade Concept

This is a pretty shoddy "concept art" but here's my best shot at explaining what you're looking at...

Basically there are three parts. The outer casing.(purple) The inner casing.(Blue) The Blade.(Red) Both the inner and outer cases have stoppers(Light Purple and Cyan) in them. Each moving part is cut to have a shape that moves through the case(s) and has "fins" on each side that catch onto the stoppers. Notice how the Inner case(Blue part) has two fins on each side. It's essentially shaped like a cross. It will slide through the case, catch the outer casing's stoppers(Light Purple) and stop. The blade also has fins which catch the stoppers of the inner case(Cyan). All parts are gravity operated, but they can be slung out with force for a forward motion extension or even upwards(though hard to do considering it's wood). Not as smooth as metal, but it does what it's supposed to. Plus, slinging it out like that wouldn't be very low-profile, assassin-like. I hope this has been a decent description so far.

Now that that's out of the way... lets talk about how it all locks into place.

While in rest, a metal latch secures it all from falling out. This latch has a string that is tied to a ring. Pulling one's wrist back lifts this latch and gravity does it's job. All parts stop against each other's fins and stoppers, and the latch will secure it via a grove cut into the inner case. This grove is also cut right above where the end of the blade would be. So it locks behind the blade preventing it and the inner case from falling back in until you pull your wrist back again. This grove can be seen in the video posted in the Pre-Complete submission here ->[link]<- As well as a description of how it's put together. Or if you've already seen the finished product and missed the video in the description, here's a shortcut to the video ->[link]<-