Multi-window sash and batten attachment structure

摘要

A multi-window sash comprising: a frame structure; a plurality of sash units, to each of which a panel is mounted which are connected with each other in a panel width direction, each of the sash units comprising bilateral vertical frame members, an upper frame member and a lower frame member which constitute a rectangular frame of the sash unit in combination thereof; and a mullion structure connecting adjacent two sash units and including at least a mullion having an expandable structure. The expandable mullion structure comprises a first mullion section attached to one sash unit and having one side surface in a panel width direction provided with a recessed portion and having water-tight member attachments and guide pieces which are attached to respective opposing inner surfaces of the recessed portion, water-tight members mounted to the respective water tight member attachments, and a second mullion structure attached to another one sash unit adjacent to the one sash unit and fitted to the recessed portion of the first mullion section in the panel width direction. The water-tight members are mounted so as to be pressed against both side end surfaces in a panel thickness direction of the second mullion section and the guide pieces are disposed so as to oppose to both the side end surfaces in the panel thickness direction of the second mullion section with gaps, respectively, to thereby impart an expandable function to the first and second mullion sections.