Top-hung window

A window, for mounting in an inclined roof surface, comprising a frame structure with top, bottom and side members (1-3) and a relative to the frame structure openable, top-hung sash structure with an insulating pane (4) encased between top, bottom and side members (5-7) of metal sheet profiles with a substantially L-shaped cross-section with a first wall portion covering a narrow edge zone of an exterior surface of the insulating pane (4) and a second wall portion (5a-7a) extending substantially in parallel with an edge surface of the insulating pane, a pivoting hinge provided at the top members (1,5) of the frame and sash structures, the axis of which pivoting hinge is defined by engagement between a hook member (39) integral with said second wall portion (5a) of the metal sheet profile of the sash top member and a hinge pin forming member (38) of a fitting member (37) connected with the frame top member, as well as securing means for maintaining the engagement between the hook member and the hinge pin forming member within a predetermined range of opening angle for the sash structure, characterized in that said hook member (39) is substantially V-shaped with a first portion extending substantially perpendicular to the second wall portion (5a), and a second portion angular relative thereto, that the fitting member (37) is substantially L-shaped and that the hinge pin forming member (38) in the closed position of the window abuts said first portion of the V-shaped hook member (39), and that said securing means are constituted by holding means (40,41), which are fastened to at least one adjacent pair of the side members (2,6) of the frame and sash structures, and which in an opening angle range which, calculated from the closed position, is smaller than the opening angle of the V-shaped hook member, hold the V-shaped hook member (39) and said hinge pin forming member (38) in mutual engagement, but which, when turning the sash structure beyond said opening angle range, allow removal of the sash structure from the frame structure.