Abstract: Provided is a ring including at least one crown; and angular sectors disposed circumferentially contiguous and substantially inside the crown and configured to be translated along substantially radial sliding axes defining a contracted configuration in which the angular sectors are mutually in contact so that the ring defines an inner diameter of minimum value; and at least one expanded configuration in which the angular sectors are spaced apart so that the inner diameter of the ring has a value greater than the minimum value.
Abstract: Provided is a ring including at least one crown; and angular sectors disposed circumferentially contiguous and substantially inside the crown and configured to be translated along substantially radial sliding axes defining a contracted configuration in which the angular sectors are mutually in contact so that the ring defines an inner diameter of minimum value; and at least one expanded configuration in which the angular sectors are spaced apart so that the inner diameter of the ring has a value greater than the minimum value.