US Patent 7374835 Fuel cell element

A fuel cell element comprising a tube of a solid electrolyte. An outer electrode is provided on an outside of the tube and an inner electrode is provided in the inside of the tube. A ring formed of an electrically conducting material is mounted to the tube and is electrically connected to the tube. The ring has a first surface intended to be mountable to and slidingly engageable with a substantially complementary shaped second surface of a wall of a conduit means to supply a gaseous consumable to an interior of the tube or to carry gas from the interior. The mounting of the ring to and the engaging of the ring with the second surface is to provide an electrical connection between the fuel cell element and the conduit means.