Patent attributes
A rotation assistance mechanism equipped with an attraction unit having a pair of magnetic bodies for which the opposite poles of the bodies are arranged facing one another. A magnetic body driving unit changes the distance between the pair of magnetic bodies with a prescribed period by means of the rotation of a rear wheel. A shielding unit has a pair of magnetic surfaces, the poles of which are the same as the respective opposing surfaces of the pair of magnetic bodies. A shield-driving unit that, in conjunction with the prescribed period, propels the shielding unit into the interval between the pair of magnetic bodies when the distance between the pair of magnetic bodies is reduced, and retracts the shielding unit from the interval between the pair of magnetic bodies when the distance between the pair of magnetic bodies is increased.
