Hinge to connect the legs and frame of a pair of spectacles

A hinge for connecting a leg to a frame for a pair of spectacles, comprising:

• a first element solidly fixed to the frame, the first element having a cam-shaped end including first and second surfaces formed as inclined planes at an angle to each other and separated by a vertex;
• a leg pivotally connected to the first element, the leg having a longitudinally extending seating, a sliding element slidable in the seating and means for resiliently thrusting the sliding element toward the first element, the sliding element having a forward end adjacent the first element with an inclined plane and having a lateral extension forming an abutment tooth;
• a connection pivot connecting the leg to the first element to allow pivotal movement of the leg with respect to the first element about the connection pivot from a closed position in which the inclined plane of the forward end of the sliding element is thrust into contact with the first surface of the cam-shaped end profile of the first element, past an intermediate position in which the inclined plane of the forward end of the sliding element is in contact with the vertex of the cam-shaped end profile of the first element thrusting the sliding element rearward in the seating, to an open position in which the inclined plane of the forward end of the sliding element is thrust into contact with the second surface of the cam-shaped end profile of the first element, and to a past opened position in which the inclined plane of the forward end of the sliding element is at an angle to the second surface of the cam-shaped end of the first element thrusting the sliding element rearward into the seating.