Abstract

An engine chain or belt tensioning system includes a tensioner pivot arm with a ratcheting means that includes backlash in an engine timing system. The tensioner system includes a tensioner pivot arm having a fixed pin, ratchet teeth, and a connection for a rotation-causing device, all being spaced radially outward from a pivoting feature. The pivoting feature and the fixed pin are positioned between two strands of a chain. An arm carrying a shoe extended outside the strands of chain and positioned to contact an outside portion of chain is pivotally mounted to the fixed pin. Rotation of the pivot arm causes the arm and shoe to draw inwards, imparting tension to the chain strand. The ratchet teeth allow free rotation of the tensioner arm in one direction, but not the other.