Abstract: A binding machine for booklets comprises:a movable hood carried by the frame, covering the aligned stations and defining, for the carriage, an elongated passage opening, parallel to the path and whose length is equal to the course of reciprocating movement of the carriage,and a band of relatively flexible material fixed and held taut at both ends of the carriage, having a width in excess of the window and guided by the frame so that a part thereof always shuts off the window at both ends of the carriage whatever the position thereof, said band extending in a plane under the window and above the stations.