Abstract: A hydraulic hinge that includes an elongated tubular member in which a first ring member with an axial opening and a downward projection is fixed and a second ring member having an opening aligned with the opening of the first ring member and a notched portion having a cam face to abut against the projection of the first ring is provided. A hollow shaft with a closed bottom and a first fluid filled piston chamber within the same is inserted through the openings of the first and second ring members, whereat the second ring member is sealed in a sleeve around the hollow shaft. The hollow shaft has an opening formed adjacent to its bottom closed. A seal member is sealed around the hollow shaft wherein the inner surface of the elongated tubular member, the second ring member, the seal member and the outer wall surface of the hollow shaft cooperatively confine a second fluid filled chamber which is in communication with the first hydraulic chamber through the opening.