US Patent 7798836 Electric plug connector with hermaphrodite contact element

An electric plug connector with hermaphrodite contact elements (100) having the following features: an electric contact element (100) of a first plug connector opens toward a second electric contact element (100) like a fork, the inner surfaces of the forks, which comprise two legs (110, 120) each, embrace at least in part one leg (120, 110) of the matching other contact element, and is characterized by the following features: one of the two legs (110) comprises a projection of convex shape (111); the other one of the two legs (120) comprises a concave recess (121); and the shape of the concave recess (121) is adapted to the convex projection (111) so that in the engaged condition of two plug connectors the convex projection (111) of the first plug connector is in positive contact, at least in part, with the concave recess (121) of the second plug connector, or vice versa.