hook portion 76 engages the opening 116 of the projection 114 the teeth 92 94 of the sliders 80 82 engage the respective seats 104 106 of the movable striker 100 of the connecting device 96 the closing element 88 of the slider 82 engages a respective fixed striker 20 all the closing elements 22 of the locking device 18 engage the respective fixed strikers 20 in this condition the wing 14 is locked relative to the frame 12 along the lower horizontal side the upper horizontal side and along the vertical side opposite to the articulation axis of the wing 14 starting from this condition the control device 28 allows unlocking and opening of the wing 14 solely by the rotating movement of the handle 40 rotating of the handle 40 drives the gear wheel 46 in rotation by means of the worm screw 42 with reference to fig1 and 14 in a first step the gear wheel 46 controls the movement in the rectilinear direction of the arm 32 in the direction indicated by the arrow a as a result of the meshing of the gear wheel 46 with the straight portion 74 of the toothing 70 following this movement as shown in fig1 and 14 the pin 108 disengages from the straight guide 68 and engages the articulation seat 66 one arcuate wall 112 of the pin 108 comes into contact with the circular wall of the articulation seat 66 in a position opposite to the straight guide 68 in this position the pin 108 is completely disengaged from the straight guide 68 and only engages the circular articulation seat 66 in this condition the gear wheel 46 meshes with the end of the straight toothed portion adjacent to.