locking mechanisms 230 250 and once the gap is a sufficient distance the force due to magnetism decreases rapidly the compression forces due to the springs 260 continue to resist rotation of the parts but with a substantially constant force due to the angle of the springs 260 relative to the direction 234 of movement fig3 a shows a continued transition from the open state in fig2 a to a state where the parts 110 120 are at nearly 90 degrees as the part 120 continues to rotate relative to part 110 the gap shown at 310 opens to a distance d between the first and second locking mechanisms 230 250 due to the limited reach of the flexible connection member the compression spring force due to the springs 260 remains at a relatively constant value fig3 b shows the parts 110 120 in a closed state with the distance d 310 between the first and second locking mechanisms 230 250 at a maximum fig4 shows an assembly drawing of a hinge mechanism 410 according to another embodiment in this embodiment the second locking mechanism 420 is formed by a magnet 422 sandwiched between iron sheets 424 426 the iron sheets serve to control the magnetic field formed by the magnet 422 so as to keep the magnetic field within the second locking mechanism the iron sheets 424 426 can be formed from any ferromagnetic material such as those described above a first locking mechanism 430 is labeled.