Hidden hinge

A hinge for the pivotal connection a movable sash to a fixed frame of a window, said fixed frame and said sash comprising respectively a vertical upright defining a vertical rotation axis (X) of said sash with respect to said frame and a horizontal crosspiece defining a horizontal axis (Y) perpendicular to said rotation axis (X), said axes defining with a third perpendicular horizontal axis (Z) a main Cartesian coordinate system and three consequent planes, horizontal plane (YZ), first vertical plane (XZ) and second vertical plane (XY), said hinge comprising:

• a first element adapted to be connected to said fixed frame and a second element adapted to be connected to said movable sash;
• a system of levers hinged with each other, which connects said first element to said second element so as to obtain at least a roto-translational movement of said second element with respect to said first element and, consequently, of said sash with respect to said fixed frame;
• wherein said second element comprises a plug pivotally connected to said system of levers, a main body defining a seat housing with play said plug, and a cover element which engages with play on said body and is integrally fixed to said vertical upright, adjusting means also being provided for adjustment of the relative position of said sash and said fixed frame, said adjusting means exerting during operation a pushing force respectively on said plug, on said body and on said cover element in three directions (X, Y′, Z′) defining a secondary Cartesian coordinate system, one of said directions being defined by said rotation axis (X), said secondary Cartesian coordinate system corresponding, in the closed position of the sash, to said main Cartesian coordinate system, so that these pushing movements performed by said adjusting means in said three directions cause an adjustment of the distance of said sash from said fixed frame with respect to said second vertical plane (XY), said horizontal plane (YZ) and said first vertical plane (XZ).