Device for locking a movable element of an automobile vehicle seat onto a fixed element with unlocking indication

Device for locking a movable element of an automobile vehicle seat onto a fixed element, this device including:

• a locking component attached to a first of the elements and penetrating, in a locking position, into a window made in a second of said elements, a movable lock attached to the second element and adapted to cooperate, in the locking position, with the locking component, and a button for activating unlocking and installed so as to slide in a guide well between a position indicating unlocking, where an upper end of the button is exposed from an upper edge of the well and, an unlocking control position where the upper end of the button is located inside the well while a lower end of the button pushes the lock into an unlocking position enabling disengagement of the locking component, the device further including a spring returning the button to its position indicating unlocking, and button movement control means to place the button in an intermediary position where the upper end of the button is substantially flush with an edge of the well, the control means being arranged so as to be activated by the locking component only when the locking component is in the said locking position.