Mechanism for opening/closing a latch for a motor vehicle door leaf

An opening/closing assistance mechanism for assisting opening and closing of a latch of a door leaf, the opening/closing assistance mechanism comprising:

• an electric actuator configured to control a closing and an opening of the latch, the electric actuator including a reducer comprising a drive device configured to perform a displacement stroke, wherein the displacement stroke comprises a first stroke portion for opening the latch and a second stroke portion for closing the latch, wherein the reducer includes a first reduction ratio on the first stroke portion and a second reduction ratio on the second stroke portion, the first reduction ratio being different from the second reduction ratio,
• wherein the reducer comprises a first lever arm controlled in displacement by the drive device when the drive device performs the first stroke portion, a second lever arm controlled in displacement by the drive device when the drive device performs the second stroke portion, and a transmission device configured to be driven by the drive device, and to drive cause the first and second lever arms to pivot around a first axis and a second axis, respectively, the first axis being different from the second axis, the second lever arm being disposed on the transmission device so that the transmission device has an axis of rotation coinciding with the second axis the second lever arm, and
• wherein at least one of the transmission device and the drive device is a wheel, and the displacement stroke is a rotation.