Patent ID: 8307505

Claim:
A rotation control device connected to a rotation body and a fixed body for maintaining an attitude of the rotation body relative to the fixed body at a pre-advancement position corresponding to a post-return position (a), and a post-advancement position corresponding to a pre-return position (b), respectively, comprising: a first rotation part supported on the fixed body so as to rotate as the rotation body rotates, a second rotation part rotatably supported on the fixed body at a side of the first rotation part, a torsion coil spring having one end supported by the first rotation part, the other end supported by the second rotation part, and a wound portion between the one and the other ends, and a spring holder having a supporting axis passing through the wound portion and a supporting portion for supporting the first rotation part or the second rotation part, wherein when the first rotation part rotates, the second rotation part rotates together with the first rotation part, and the wound portion of the torsion coil spring is most elastically deformed when the rotation body is at an intermediate rotational position (c) positioned between the position (a) and the position (b), and the one end or the other end of the torsion coil spring is supported at the first rotation part or the second rotation part through the spring holder.