Pitch-change mechanism with locking device

A pitch-change mechanism for adjusting an angular position of at least one variable-setting blade of an aircraft turbomachine around a pivot axis of the variable-setting blade, said pitch-change mechanism comprising:

• a frame fixed relative to the pivot axis,
• a control actuator including a fixed part integral with the frame and a movable part that is translatable along a longitudinal axis with respect to the fixed part between a retracted position and a deployed position,
• a connecting system connecting the movable part to the variable-setting blade so as to convert the translation of the movable part along the longitudinal axis into a rotation of the variable-setting blade around the pivot axis, and
• a pitch locking device suitable for locking the translation of the movable part with respect to the fixed part in at least one direction,
• wherein the pitch locking device comprises:
• a surface integral with the frame or movable jointly with the movable part with respect to the frame,
• a locking member having an unlocked configuration away from the surface and a locked configuration engaged with the surface such that the movable part is immobilized with respect to the frame,
• a movable member that is translatable with respect to the locking member between a retracted position in which it leaves the locking member free to be in its unlocked configuration and a deployed position in which it forces the locking member into its locked configuration,
• a biasing member which urges the movable member toward its deployed position, and
• a holding device for holding the movable member in its retracted position under certain predetermined conditions, and wherein the locking member comprises at least one deformable element elastically deformable, having at rest a first radial thickness and, when compressed parallel to the longitudinal axis, a second radial thickness greater than the first radial thickness, the locking member being in the unlocked configuration when the deformable element is at rest and in the locked configuration when the deformable element is compressed parallel to the longitudinal axis.