Device for hanging a curtain in front of a window

A device for hanging a curtain in front of a window, comprising:

• a curtain rod (2) for supporting a curtain;
• and
• two sub-assemblies (1), each said sub-assembly (1) comprising a plate (5) and an offset arm (6), wherein,
• a first of the sub-assemblies mounts to a first casement window frame and a second of the sub-assemblies mounts to a second casement window frame, an upper edge of each said casement window frame being defined by a top edge of the casement window frame and a side edge of the casement window frame, each said casement window frame (3) having a pivoting axis,
• each plate (5) comprises a mounting part (8) that fits on the upper edge of one of the casement window frames (3),
• the mounting part (8) comprises i) a lateral extension (9) that, with the mounting part (8) fitted on the upper edge of the casement window frame, projects beyond the side edge of the one casement window frame (3), and ii) a pivoting element (10) integral with the lateral extension (9), the pivoting element defining a pivoting axis coaxial with the pivoting axis of the one casement window frame (3), and
• each offset arm (6) comprises i) a first end and an opposite second end, ii) at the first end, a pivoting part (14), each said offset arm (6), with the pivoting part (14) mounted on the pivoting element (10) of a corresponding one of the plates (5), being pivotable with respect to said pivoting axis of said pivoting element, and iii) at the second end, a connection part (15, 16) that connects the offset arm (6) to the rod (2) such that the second end of the offset arm (6) is non-pivotable with respect to the rod (2).