What is this?

What is this for the attached photo? an artifact? a decoration? or something useful? If it is useful, what do you think this was for?

The object shown in the lower photo is called the Ti-Ka-Teh, literally translated as Iron-made-scissors. The spring-like iron-rings on both sides were used to hold wood beams perpendicular to the wall-plane in place. The vertical 'nail-like' object at the front and another 'nail-like' object, (not seen on the lower photo, but shown in the illustration) were used so that the wood beams are anchored to the brick wall. (See the illustration on top photo.)

This object was seen in the Anping Fort. It is a remain of the Dutch architecture of the fort built in 1624.