(B) opens or releases a blade from the handle or
sheath by the force of gravity or by the application of centrifugal
force.
That in itself is interesting as centrifugal force itself is psudeo-scientific jargon (the favorite language of weapon banners worldwide) and either refers to a frame of reference, or is used to describe components of centripetal force. If you've ever used a flick of the wrist to open your folder, you've just made a switchblade.

Of course, I've been issued a Gerber that is an auto-opener, and definitely meets the switchblade requirement on the first definition. Push the handle mounted button, and out springs the blade. Too bad, it's a very sharp blade, and holds a heck of an edge. It'd skin a deer real nice like.