US Patent 7040062 Dismantable protective window

A reinforced window system for mounting within an opening in a wall, the window system comprising a frame fixable to the wall and a second frame, which is removably installable in the first frame. The first frame is provided with a plurality of fixing members distributed on the inside perimeter of the first frame. The second frame carries a reinforced window pane. The second frame is provided with a plurality of support members distributed on an outside perimeter of the second frame with possibility to face the fixing members of the first frame so as to support the second frame when the support members are in engagement with the fixing members of the first frame.