Guide device for guiding a driving bar of a mandrel or for guiding a mandrel in a rolling process of tubular bodies

A device for guiding a movable element in a rolling mill with mandrel, wherein said movable element is a driving bar of a mandrel or a mandrel, wherein said device comprises a support structure which defines an advancement direction for said movable element, wherein said device comprises a first slide and a second slide which are carried by said support structure and are slidable along a transverse direction which is orthogonal to said advancement direction, wherein each of said slides carries two abutment surfaces for guiding said movable element, each of said slides being movable along said transverse direction between at least a first operating position in which, when reached, said abutment surfaces come into contact with a movable element of a first predefined diameter, and at least a second operating position in which, when reached, said abutment surfaces come into contact with a movable element of a second predefined diameter, said device comprising actuating means which move said slides along said transverse direction between said operating positions and lock said slides when one of said operating positions is reached;

• wherein said actuating means comprise a first moving unit for said first slide and a second moving unit for said second slide, wherein at least one of said moving units comprises:
• an articulated mechanism configured to take on at least a first configuration corresponding to said first operating position and a second configuration corresponding to said second operating position;
• thrust means for varying the configuration of said articulated mechanism;
• and wherein said articulated mechanism comprises:
• a first pair of levers and a second pair of levers and wherein for each pair of levers, a first lever is hinged to a first part of said support structure and a second lever is hinged to said first lever and to one of said corresponding slides;
• a connecting rod which connects said first lever of said first pair of levers to said first lever of said second pair of levers, wherein said connecting rod synchronizes the rotation of said first levers, and
• wherein said thrust means are connected to said connecting rod or to one of said levers.