Todays patent is one of Arnstein’s 31 U.S. patents.
“According to my invention the girders or ribs of the fins at those
cross sections of the ship where there is a ring are carried right
through this ring to the opposite ring corners there joining the
girders or ribs of the oppositely situated fin. Usually there are
four fins placed at the ships stern and therefore according to my
invention the rings in the stern will be intersected by two pairs
of girders connecting the ring corners where as fin ribs join.
At the points of intersection of these girders they are connected
together and the panels which are formed by the ring girders
and reinforcing girders are braced so as to constitute together with
the ring a kind of circular truss. Thereby a perfect reinforcement
of the ships stern is attained making certain a secure way of
transmitting the air stresses from the fins to the hull structure. It is
of the highest importance to have to a safe construction in the
ships stern where the stresses on the fins and on the rudders and
elevators attached to them may vary greatly in strength as well as
NOTE: Curiously, although the text mentions the rudders and
elevators, none of the claims address these control surfaces, their
means of attachment or positioning equipment. Perhaps that explains
why the USPTO didn’t assign 244/87 (Rudders & empennage).
The patent is not cited by any modern patents.