Abstract: A ceiling provided with a plurality of rigid panels. Presser means tending to press each panel longitudinally against at least one adjacent panel. At least one panel is a “sliding panel” carried by a guide device so as to slide in a sliding plane. One panel is a “retractable panel” movable from an open position towards a closed position, the sliding panels being free to move in longitudinal translation along the guide device when the retractable panel is in the open position and being locked while being arranged longitudinally one after another when the retractable panel is in the closed position. The ceiling comprises movement means for moving the retractable panel in reversible manner from the closed position to the open position.

Abstract: A fastener device provided with at least one movable stud and a stationary stud, the movable stud including first magnetization means that co-operate with second magnetization means of the stationary stud. At least one magnetization means is carried by a ball joint, each magnetization means being carried by movement means that cause the magnetization means to move in translation along a longitudinal axis from an engagement position to a disengagement position in reversible manner, the magnetization means being strongly magnetically attracted to each other when they are facing and each in the engagement position and being magnetically attracted only slightly or not at all when at least one magnetization means is in the disengagement position.

Abstract: A fastener device provided with at least one movable stud and a stationary stud, the movable stud including first magnetization means co-operating with second magnetization means of the stationary stud. One magnetization means is carried by a ball joint, each magnetization means being carried by movement means in order to move the first magnetization means in translation in a plane and to move the second magnetization means in translation along a longitudinal axis that is substantially orthogonal to the plane from an engagement position to a disengagement position in reversible manner, the magnetization means being strongly magnetically attracted to each other when they are facing and each in the engagement position and being magnetically attracted only slightly or not at all when at least one magnetization means is in the disengagement position.

Abstract: A ceiling provided with a plurality of rigid panels. Presser means tending to press each panel longitudinally against at least one adjacent panel. At least one panel is a “sliding panel” carried by a guide device so as to slide in a sliding plane. One panel is a “retractable panel” movable from an open position towards a closed position, the sliding panels being free to move in longitudinal translation along the guide device when the retractable panel is in the open position and being locked while being arranged longitudinally one after another when the retractable panel is in the closed position. The ceiling comprises movement means for moving the retractable panel in reversible manner from the closed position to the open position.

Abstract: A fastener device provided with at least one movable stud and a stationary stud, the movable stud including first magnetization means co-operating with second magnetization means of the stationary stud. One magnetization means is carried by a ball joint, each magnetization means being carried by movement means in order to move the first magnetization means in translation in a plane and to move the second magnetization means in translation along a longitudinal axis that is substantially orthogonal to the plane from an engagement position to a disengagement position in reversible manner, the magnetization means being strongly magnetically attracted to each other when they are facing and each in the engagement position and being magnetically attracted only slightly or not at all when at least one magnetization means is in the disengagement position.

Abstract: A fastener device provided with at least one movable stud and a stationary stud, the movable stud including first magnetization means that co-operate with second magnetization means of the stationary stud. At least one magnetization means is carried by a ball joint, each magnetization means being carried by movement means that cause the magnetization means to move in translation along a longitudinal axis from an engagement position to a disengagement position in reversible manner, the magnetization means being strongly magnetically attracted to each other when they are facing and each in the engagement position and being magnetically attracted only slightly or not at all when at least one magnetization means is in the disengagement position.