Linkage mechanism for driving aircraft landing gear bay door

A linkage mechanism for driving an aircraft landing gear bay door, the linkage mechanism being suitable for connecting with bay doors that control access to the inside of a landing gear bay and with a landing gear and converting a back-and-forth movement of the landing gear between a retracted position inside of the landing gear bay and a released position outside of the landing gear bay, respectively into a back-and-forth movement of the bay doors between a closed position and an open position, the linkage mechanism comprising:

• a primary torsion tube comprising a first portion located inside the landing gear bay and a second portion outside the landing gear bay;
• a first drive apparatus connected between the first portion and a landing gear strut so as to transfer the driving force of the strut to the primary torsion tube;
• a secondary torsion tube comprising an inner end portion located inside the landing gear bay and an outer end portion outside the landing gear bay;
• a secondary drive apparatus connecting the outer end portion and the second portion for transmitting a torque of the primary torsion tube to the secondary torsion tube;
• and
• two third drive apparatuses respectively connected between the inner end portion of the secondary torsion tube and one of the bay doors so as to enable the bay doors to be driven by the secondary torsion tube for accomplishing the opening and closing movement.