Hey guys. I'm currently working on some mechanical parts. For this I need to model a couple of hinges and I want to animate them opening and closing. The problem is that I don't have much rigging experience and I can't get it to work.

Here is a example of the hinge I'm trying to rig:


English is not my native language so I have trouble explaining my problem.
The hinge bends on two places and these parts are connected in the middle. I just don't now how I can make sure these parts stay connected.
Right now I've got two skeletons set up with IK handles but as you can see in the following images the parts don't stay together. Should I add another joint at that point and constrain that somehow?
I made a simplyfied version of the hinge system to try out different ways to rig it.





And here is an image of the actual model (not finished yet)