A device for sealing a bay provided in a structure, comprising: a fixed part, wherein an opening is defined, and at least one sliding movable panel which is guided along two guide rails (114, 115) mounted on one face of said fixed panel, between a closed position, sealing said opening, in a first plane defined by said fixed panel, called the sealing plane, and at least one open position, in a second plane, called the sliding plane, substantially parallel to said sealing plane, each of said guide rails (114, 115) carrying at least one shuttle (2, 3) guided in translation in said rail (114, 115), each shuttle (2, 3) comprising two guide tracks, respectively two fixed pins, capable of cooperating respectively with two fixed pins, respectively two guide tracks, carried by a frame carried by said movable panel, actuating means acting on one of said shuttles to ensure a translational movement of the latter in said guide rails (114, 115), and the passage of the movable panel from said sealing position to said at least one sliding position, and vice versa, two synchronisation cables (41, 42) each circulating in one of the lateral edges of said frame and ensuring synchronisation of the movement of said shuttles (2, 3), characterised in that each shuttle (2, 3) carries a slider movable relative to said shuttle (2, 3) and receiving one end of each of said synchronisation cables (41, 42), so that the movement of said ends of said synchronisation cables (41, 42) is substantially parallel to the plane of said movable panel during the movement of said shuttles (2, 3) ensuring the passage of said movable panel from said sealing position to said at least one sliding position, and vice versa. a fixed part, wherein an opening is defined, and at least one sliding movable panel which is guided along two guide rails (114, 115) mounted on one face of said fixed panel, between a closed position, sealing said opening, in a first plane defined by said fixed panel, called the sealing plane, and at least one open position, in a second plane, called the sliding plane, substantially parallel to said sealing plane, each of said guide rails (114, 115) carrying at least one shuttle (2, 3) guided in translation in said rail (114, 115), each shuttle (2, 3) comprising two guide tracks, respectively two fixed pins, capable of cooperating respectively with two fixed pins, respectively two guide tracks, carried by a frame carried by said movable panel, actuating means acting on one of said shuttles to ensure a translational movement of the latter in said guide rails (114, 115), and the passage of the movable panel from said sealing position to said at least one sliding position, and vice versa, two synchronisation cables (41, 42) each circulating in one of the lateral edges of said frame and ensuring synchronisation of the movement of said shuttles (2, 3), characterised in that each shuttle (2, 3) carries a slider movable relative to said shuttle (2, 3) and receiving one end of each of said synchronisation cables (41, 42), so that the movement of said ends of said synchronisation cables (41, 42) is substantially parallel to the plane of said movable panel during the movement of said shuttles (2, 3) ensuring the passage of said movable panel from said sealing position to said at least one sliding position, and vice versa.