Patent ID: 8333673

Claim:
A rotation direction switching device that is disposed in a drive power transmission path from a drive power source to a drive shaft and is used for switching a rotation direction of the drive shaft to forward rotation and reverse rotation, the rotation direction switching device comprising: a forward rotation drive pulley and a reverse rotation drive pulley connected to an output shaft of the drive power source; a forward rotation driven pulley and a reverse rotation driven pulley connected to the drive shaft; a forward rotation drive belt trained around the forward rotation drive pulley and the forward rotation driven pulley; a reverse rotation drive belt trained around the reverse rotation drive pulley and the reverse rotation driven pulley; belt switching means for switching one drive belt among the forward rotation drive belt and the reverse rotation drive belt to a tensioned state and the other drive belt to a relaxed state; and a gear mechanism for forwardly rotating the drive shaft when the forward rotation drive belt is switched to the tensioned state, and reversely rotating the drive shaft when the reverse rotation drive belt is switched to the tensioned state, wherein the belt switching means further comprises a connecting member connected to a switching lever that is secured to a rotary body and to a spring, the connecting member rotating via a connector pin and having an interference prevention part formed so as to prevent interference with a rotary shaft that serves a center of rotation of the rotary body, wherein the interference prevention part is a concave part of the connecting member formed in a position facing the drive shaft, wherein the spring is additionally connected to a fixed frame body, and wherein the spring has a tension force configured to urge the rotary body in a first direction to maintain one of the forward rotation drive belt and the reverse rotation drive belt in a tensioned state wherein when the rotary body is rotated against the tension force of the spring by more than a predetermined amount in a second direction to switch the other of the forward rotation drive belt and the reverse rotation drive belt to a tensioned state, the tension force acts to urge the rotary body in the second direction.