| 摘要 |
PURPOSE:To enable to interrupt transmission of power in a reliable manner, by forcibly increasing the distance between a pair of sheaves of a power transmitting V-pulley by bringing a tension roller into engagement with the V-pulley at the time when a V-belt comes to a position near the minimum effective diameter of the V-pulley. CONSTITUTION:When a V-belt 6 is depressed through operation of a tension roller 7, the effective diameter of a power transmitting V-pulley 2 is varied gradually and stepless transmission of power is achieved. Further, when the V-belt 6 is positioned near the minimum effective diameter of the V-pulley 2 by further depressing the tension roller 7 downward, the tension roller 7 is positioned between a pair of sheaves 9, 11 of the V-pulley 2 and forces these sheaves open against the force of a spring 12 to increase the distance between them to a considerable extent. Resultantly, the opposite side faces 21 of the V-belt 6 come out of contact with the V-pulley 2 and the bottom face 22 of the V-belt 6 is kept away from a driving shaft 3, so that transmission of power is interrupted perfectly. |
