Folks, the intent of the construction is to be able to set the specific varying angle between planks. The same mechanism is used for example in the universal folding rear car door bicycle rack construction to adjust for various slants of that door (or to the low trunk) on various cars.
I would make straight teeth instead, otherwise, the grip will depend on the tension. In that case, a bungee cord (or HD rubber band) will be enough to hold pieces at needed angle (in case the force is perpendicular to the teeth of course)