Sun Sep 03, 2017 7:35 am by Deadlock
Hmm. Using Google Translate, "Einschtekschloss" means mortise lock. That can't be what you're thinking of, surely.
I have a PVC front door with a euro cylinder and the 3-point locking system. You can lock the door with just the bolt by turning the key. If you lift the handle up, this brings the 'claws' of the 3-point system out, and then turning the key locks the door. The handle returns to it's normal position. You only have to turn the key once.
One way of finding out what sort of cylinder you have is by trying to remove it. As femurat said, it's dead easy to change these cylinders. Put the key in the lock, either side. Remove the long retaining screw above below the bolt. Turn the key one way or the other a little to move the cam in line with the body of the lock, and pull it out.
If you can pull the cylinder out, obviously it's the normal type. If you can't, then it would be the gear. No idea what to do with those!
Edit: BELOW. The screw below the bolt!