US Patent 7337497 Magnetic hinge

A magnetic hinge defining a hinge axis includes first and second hinge plates of non-magnetic material and first and second magnets disposed therein, respectively, for movement therewith. The plates are generally parallel and independently pivotable about the hinge axis between a closed orientation, wherein the plates are essentially superposed, and an open orientation, wherein the plates are essentially not superposed. The first and second magnets are essentially superposed, generally coaxial with the hinge axis, and in the same magnetic orientation.