Joint structure designed for connecting a movable element (1) made of a mainly sheet-like-material in an articulated manner to a frame part (2) made of a mainly sheet-like material. The joint structure comprises a pivot part (3) attached to the frame part (2); a bearing part (4) provided with an aperture (5) and mounted on the pivot part by its aperture; and a locking part (6) which is attached to the pivot part to lock the bearing part between the frame part and the locking part so as to allow rotation of the bearing part.