Kinematics of Invisible Hinge

Invisible or concealed hinge, having three fixed axes and two slide-able rotational axes, is widely used in the different closures like home doors, laundry machines, cockpit hatches of the boats and even in the notebook computers. The employ of this type of hinge is more advantageous with respect to the traditional surface-mounted hinges in terms of security and aesthetic design. Unfortunately, due to the lack of knowledge of kinematics of the hinge, the trajectory of the hinge movement is defined empirically in the known designs, and, as a consequence, all these solutions are not optimal. In this paper, we have analyzed the kinematics of five axes hinge, we have obtained the principal analytical relationships between constructive elements and, as a result, we can control the trajectory of hinge by means of following parameters: starting angle between hinge brackets, ratio of the brackets length, and shape of sliding guides. Therefore, this analytical approach can be used as a tool for the design of the concealed hinge which allows having a desirable trajectory of the door movement.