Anti-torque rotor for a helicopter

An anti-torque rotor (4) for a helicopter (1), comprising:

• a mast (6), rotatable about a first axis (A);
• a plurality of blades (8), hinged on said mast (6), extending along respective second axes (B) transversal to said first axis (A) and rotatable about respective said second axes (B) to vary the respective angles of attack;
• a control element (16), sliding along said first axis (A) with respect to said mast (6), integrally rotatable with said mast (6), and operatively connected to said blades (8) to cause the rotation of said blades (8) about respective said second axes (B) following a translation of said element (16) along said first axis (A);
• a control mechanism (10), sliding axially along said first axis (A) with respect to said mast (6) and angularly fixed with respect to said first axis (A);
• and
• a connection element (17), interposed between said control mechanism (10) and said control element (16), sliding along said first axis (A) with respect to said mast (6) and integrally with said control mechanism (10), and configured to enable the relative rotation of said control element (16) with respect to said control mechanism (10) about said first axis (A) in a correct operating configuration;
• wherein said control mechanism (10) comprises:
• a first rod (60);
• and
• a second rod (61), connected to said connection element (17);
• said rotor (4) further comprising a coupling (70), which enables said first and second rods (60, 61) to slide along said first axis (A) integrally with one another;
• said coupling (70) being configured so as to enable rotation of said second rod (61) with respect to said first rod (60) when the torque exerted, in use, by said first connection element (17) on said second rod (61) about said first axis (A) is greater than a threshold value in the event of failure of said connection element (17);
• said coupling (70) being configured so as to prevent the rotation of said second rod (61) with respect to said first rod (60) when said torque exerted, in use, by said connection element (17) on said second rod (61) is less than said threshold value.