ROTATIONAL FORCE TRANSMISSION DEVICE

There is provided a rotational force transmission device configured to transmit a rotational force and applied to a vehicle seat apparatus. The rotational force transmission device includes an input-side transmission member having a ball point, an output-side transmission member slidably coupled to the input-side transmission member and having a ball point, and an elastic member providing an elastic force to make the input-side transmission member and the output-side transmission member displaced apart from each other along a central axis direction.