Door hinge with movable and fixed cams

Abstract

According to the invention, there is provided a door hinge comprising a spring that plays the role of both a torsion spring and a compression spring, wherein its resilient force is used for axially pressing a movable cam against a matching fixed cam it comprises and thereby facilitating the opening and closing motion of the door with which it is used by giving said cams such specific configurations that the spring accelerates the opening motion of the door from a given angular position of the door and locks the door at a particular open position and at a closed position. Since a door using such a hinge that comprises a spring whose resilient force constantly biases the door to open can be either opened to any desired angle or closed and sustained there under a locked condition when the rotary shaft of the hinge is firmly connected to the door, it can be used for a flap door or another vertically rotatable door such as a toilet lid to sustain the door to an open position under a locked condition even if the resilient force of the spring is nullified at that position and the door is liable to be pushed back by an obstacle such as a wire located behind the toilet assembly comprising the lid. Therefore, the door is protected against any turning effort and other forces which are unintentionally applied to the door.