A locking device for blocking a retractable screen, the locking device comprising: - a fixed portion, and a movable portion connected to a pin, the movable portion being movable with respect to the fixed portion, - an engaging mechanism for providing engagement between the fixed portion and the movable portion, the engaging mechanism allowing a first configuration of the movable portion relative to the fixed portion wherein the pin is extended for blocking the screen, and a second configuration of the movable portion relative to the fixed portion wherein the pin is retracted for unblocking the screen, wherein the locking device further comprises - a cycling mechanism including a force member configured to provide a force between the movable portion and the fixed portion in a predetermined direction, the cycling mechanism adapted to provide a transition of the movable portion from the first configuration to the second configuration by moving the movable portion with respect to the fixed portion in a direction against the force and then releasing it, and from the second configuration to the first configuration by moving the movable portion in the same direction and releasing it wherein the movable portion is a slidable element, and the fixed portion is a sleeve for housing the slidable element, characterized in that the engaging mechanism comprises a resilient tab in one of the portions and a shaped hole in the other of the portions for releasably engaging the resilient tab, the shaped hole further comprising: - a first portion for allowing the resilient tab in a first axial position, for providing the first configuration of the pin, where the pin is extended, and - a second portion for fixing the resilient tab at a second axial position different from the first, for holding the pin in the second configuration, where the pin is retracted, the cycling mechanism comprising - a slot comprised in the shaped hole, for allowing the resilient tab to slide from the first portion to the second portion upon pushing in the pin while in the first configuration, and an edge of the shaped hole, for releasing and disengaging the resilient tab outside the shaped hole upon pushing in the pin while in the second configuration, and for allowing transitioning the tab to the first portion upon release. - a fixed portion, and a movable portion connected to a pin, the movable portion being movable with respect to the fixed portion, - an engaging mechanism for providing engagement between the fixed portion and the movable portion, the engaging mechanism allowing a first configuration of the movable portion relative to the fixed portion wherein the pin is extended for blocking the screen, and a second configuration of the movable portion relative to the fixed portion wherein the pin is retracted for unblocking the screen, wherein the locking device further comprises - a cycling mechanism including a force member configured to provide a force between the movable portion and the fixed portion in a predetermined direction, the cycling mechanism adapted to provide a transition of the movable portion from the first configuration to the second configuration by moving the movable portion with respect to the fixed portion in a direction against the force and then releasing it, and from the second configuration to the first configuration by moving the movable portion in the same direction and releasing it - a cycling mechanism including a force member configured to provide a force between the movable portion and the fixed portion in a predetermined direction, the cycling mechanism adapted to provide a transition of the movable portion from the first configuration to the second configuration by moving the movable portion with respect to the fixed portion in a direction against the force and then releasing it, and from the second configuration to the first configuration by moving the movable portion in the same direction and releasing it wherein the movable portion is a slidable element, and the fixed portion is a sleeve for housing the slidable element, characterized in that the engaging mechanism comprises a resilient tab in one of the portions and a shaped hole in the other of the portions for releasably engaging the resilient tab, the shaped hole further comprising: - a first portion for allowing the resilient tab in a first axial position, for providing the first configuration of the pin, where the pin is extended, and - a second portion for fixing the resilient tab at a second axial position different from the first, for holding the pin in the second configuration, where the pin is retracted, - a first portion for allowing the resilient tab in a first axial position, for providing the first configuration of the pin, where the pin is extended, and - a second portion for fixing the resilient tab at a second axial position different from the first, for holding the pin in the second configuration, where the pin is retracted, the cycling mechanism comprising - a slot comprised in the shaped hole, for allowing the resilient tab to slide from the first portion to the second portion upon pushing in the pin while in the first configuration, and - a slot comprised in the shaped hole, for allowing the resilient tab to slide from the first portion to the second portion upon pushing in the pin while in the first configuration, and an edge of the shaped hole, for releasing and disengaging the resilient tab outside the shaped hole upon pushing in the pin while in the second configuration, and for allowing transitioning the tab to the first portion upon release.