Yes, there is an US patent regarding the use of a rubber tube used as dampener between two objects.
This patent is valid in USA only. To get an international coverage of a patent, someone has to patent it in each country of the world.
Anyone can produce/sell items regarding US patents elswhere.
That's what the international laws state.
I could sell my mounts in USA only if I would have an agreement with the patent's holder, but I suppose that Mr Hyde wouldn't agree, remembering how much he was upset when looking at my mount during last TOC. :boxing: