Window having a bellows-type opening movement and permitting complete reversal of the window-leaf

A window having a fixed rectangular window-casing and a rectangular window-leaf movable in bellows-like manner between open and closed positions and also being completely reversable relative to said window casing comprising:

• leaf pivot means for forming a first axis of pivotal motion of said window-leaf with respect to said fixed window casing, said leaf pivot means being formed along a first side of said window-leaf and including two rollers each coupled to one of the two consecutive corners of the window-leaf and both having a common axis which coincides with the first axis of pivotal motion said first axis of pivotal motion being parallel to said first side and being movable in a direction parallel to itself;
• a first arm pivotally secured by a first pivot means to a second side of said window-leaf which side is perpendicular to said first side;
• a second arm pivotally secured by a second pivot means to a third side of said window-leaf which side is perpendicular to said first side;
• said first and second pivot means defining a second axis of pivotal motion which permits complete reversal of said window-leaf;
• said first and second arms being pivotally secured by third and fourth pivot means, respectively to opposite sides of said window casing near one end thereof;
• said third and fourth pivot means including a straight rod disposed through said casing and being freely rotatable therein, the longitudinal axis of said rod coinciding with said third axis of pivotal motion, said rod including an elastic restoring device so arranged that one end of said device is attached to the window casing and the other end thereof is attached to said rod;
• and a member operable for rotating said rod about its longitudinal axis;
• said third and fourth pivot means defining a third axis of pivotal motion;
• said second and third axes of pivotal motion being substantially parallel to said first axis of pivotal motion;
• said third axis of pivotal motion substantially coinciding with said first axis of pivotal motion when the window is operated in bellows-like manner between open and closed positions;
• said second and third axis of pivotal motion being maintained spaced apart by said first and second arms for a distance at least equal to one-half the length of the sides perpendicular to the first side;
• whereby complete reversal of said window-leaf may be achieved by rotation about said second axis of pivotal motion;
• and
• groove means defining two grooves extending over at least the full length of the windowcasing sides which are perpendicular to the common axis of the two rollers, said rollers being constrained to move within said grooves, and wherein said rod is provided at each end with an internal recess which is capable of receiving each roller, each recess being provided with an opening so as to permit the transfer of said roller from one of the grooves to the corresponding recess, the common axis of said recesses being such as to coincide with the longitudinal axis of said rod.