Turbofan comprising a set of rotatable blades for blocking off the bypass flow duct

A turbofan having a longitudinal axis and comprising a motor and a nacelle, surrounding the motor, which comprises a fan casing, in which a duct for a bypass flow is delimited between the nacelle and the motor and in which a flow of air flows in a flow direction, said nacelle comprising:

• a fixed structure fixed to the fan casing,
• a mobile assembly having a mobile cowl and a slider, the mobile cowl being fixed to the slider, the slider being mobile in translation, on the fixed structure, in a direction of translation between an advanced position in which the slider is positioned such that the mobile cowl is moved close to the fan casing and a retracted position in which the slider is positioned such that the mobile cowl is moved away from the fan casing so as to define, between them, an open window between the duct and an exterior of the nacelle,
• a plurality of blades, each one comprising a first end mounted mobile in rotation on the slider about an axis of rotation generally parallel to the longitudinal axis, where each blade is mobile between a stowed position in which the blade is outside the duct and a deployed position in which the blade is across the duct, where said plurality of blades is split into groups, where each group comprises a first blade located furthest downstream, with respect to a direction of flow, compared to other blades of the same group, where, for each group, a blade of rank ‘n’ is located upstream of a blade of rank ‘n−1’ in the direction of flow and is offset angularly about the longitudinal axis with respect to the blade of rank ‘n−1’,
• an assembly of actuators causing the slider to move between the advanced position and the retracted position, and vice versa, and
• a maneuvering system configured to move each blade from the stowed position to the deployed position and vice versa, where the maneuvering system comprises:
• a cam integral with the first blade of one of the groups and having a tooth,
• a groove, integral with the fixed structure, which receives the tooth and where, when the mobile assembly moves, the tooth follows the groove and rotates said first blade,
• a first transmission system which transmits a movement of the first blade bearing the cam to a first blade of each other group, and
• for each group, a second transmission system which transmits the movement of the blade that bears the cam or is moved by the first transmission system to each of the other blades of said group.