A lock coupling between two mechanical components and presenting: at least one pair of coupling elements, each of which presents an “L”-shape and protrudes from a first mechanical component; and at least one pair of tracks, each of which is made through a second mechanical component, presents the shape of an arc of circumference, ends with a flared inlet opening, and is engaged in use by a coupling element; each track presents a dimension so as to prevent the axial removal of the coupling element along its entire length except for an inlet opening at which the coupling element can be axially removed.