Abstract: An opening system comprising an upper bearing section bar (1) fastened to the vertical rods, a gripper for the plate (4) made up of a first section bar (2) and of a second section bar (3) and at least one moving device (5) for the plate (4); each moving device (5) is made up of a support section bar (6), a right angle gearbox, an arm (7), a gas spring (8) and a clamp (9); the right angle gearbox is made up of a first conical cogwheel (10) and a second conical cogwheel (11) engaging each other; the arm of the first conical cogwheel (10) acts as lever, transforming the axial movement of the rod of the gas spring (8) into a radial movement of the second conical cogwheel (11) and of the elements linked thereto: clamp (9), gripper for the plate (4) and plate itself (4).