Automatic tensioner apparatus

摘要

An automatic tensioner apparatus comprising an idler pulley engaging a transmission belt of a wrapping connector type transmission mechanism, an arm for swingably supporting the idler pulley with respect to a predetermined supporting surface, and a resilient member for exhibiting a resilient force for swinging the arm and the idler pulley in a direction to engage the transmission belt in order to apply a predetermined tension to the transmission belt. A casing for accommodating the resilient member is secured to the supporting surface and an arm pivot-supporting portion for swingably supporting a base portion of the arm is integrally provided on the casing in such a manner that the arm pivot-supporting portion is offset relative to the resilient member in a direction along the supporting surface and relative to the resilient member in a direction away from the supporting surface. The automatic tensioner apparatus need not be separated especially forwardly from the supporting surface to locate the so-called belt line at a front, distanced position from the supporting surface for ensuring a relatively wide space to place another functional part around the automatic tensioner apparatus between the base portion of the arm and the supporting surface. The space is obtained without difficulty.