From the "fun and games" link that Jeri put up, I note that the truss rod shown there is only one of several configurations suggested in luthiery information. The one shown is quite common, I believe; but there are variations that are recommended in some of the literature. Before starting a repair it might be a good idea to try to find information specific to the maker of the one you're intending to do the surgery on. The information you might want would be pretty basic, so you shouldn't really need to look for "blueprints." A "kind of construction" should be sufficient.

I would expect that a single builder would be likely to use the same basic configuration on all their models, although there could be a case where you need to get an idea of a less usual kind used in a specific model. (I doubt that most makers vary their methods much once they've found out what works for them.)

John