US Patent 7634837 Lift-off hinge

An embodiment of a hinge has a first part with a pin, the pin defining a longitudinal axis, and a second part with a receptacle for the pin. The first and second parts are arranged to rotate relative to one another about the axis with the pin in the receptacle. Mutually cooperating formations on the pin and receptacle are arranged to permit separation of the first and second parts along the axis in a first position of relative rotation of the first and second parts and to obstruct separation of the first and second parts along the axis in a second position of relative rotation of the first and second parts.