Patent ID: 7837000

Claim:
A tension adjustment mechanism for a vehicle including a rear arm with a cylindrical axle supporting section having a circular inside diameter arranged to support a rear axle and an eccentric hub passing through the cylindrical inside diameter of the cylindrical axle supporting section to support the rear axle rotatably in a position eccentric to a radial center of the cylindrical I inside diameter of the cylindrical axle supporting section, comprising: a part supporting member connected to the eccentric hub in such a manner as to move with a rotation of the eccentric hub; and a range limiter coupled to the part supporting member in such a manner as to limit free movement of the part supporting member to a specified movement range and therefore to limit a rotational movement of the eccentric hub to a specified movement range, wherein the range limiter coupled to the part supporting member includes a first engaging portion arranged to engage with a second engaging portion attached to the rear arm, wherein the range limiter of the part supporting member includes a first position and a second position; in the first position, the range limiter permits the free movement of the part supporting member, and therefore the range limiter permits the rotational movement of the eccentric hub; and in the second position, the first engaging portion of the range limiter engages the second engaging portion attached to the rear arm, the range limiter blocks the free movement of the part supporting member, and therefore the range limiter blocks the rotational movement of the eccentric hub.