Patent ID: 7285065

Claim:
A belt tensioner for tensioning a drive belt or timing belt of a belt drive system, said belt tensioner comprising: an eccentric adjusting member comprising an inner installation shaft and a surrounding, pivot shaft, said installation shaft having a longitudinal bore configured to receive a fixing bolt to mount said tensioner on an engine mounting surface, said longitudinal bore being offset to a central, longitudinal axis of said pivot shaft, said installation shaft of said eccentric adjusting member being rotatable in a first, belt-tightening direction and a second direction away from the first, belt-tightening direction when mounted on the engine mounting surface; a pivot structure mounted on said pivot shaft of said adjusting member for eccentric pivoting movement; a belt-tensioning pulley mounted for rotational movement on said pivot structure; a biasing member constructed and arranged to resiliently bias said pivot structure in a belt-tightening direction; and a temporary coupling structure that temporarily couples said pivot structure to said installation shaft of said eccentric adjusting member such that when said installation shaft of said eccentric adjusting member is rotated in the second direction, away from the first, belt-tightening direction, as part of an installation procedure to allow the drive belt or timing belt to be installed into the belt drive system, said pivot structure moves with said installation shaft of said eccentric adjusting member against the bias of said biasing member, and wherein decoupling of said pivot structure from said installation shaft of said eccentric adjusting member by removal of said coupling structure and securing said eccentric adjusting member in place renders said tensioner operative by enabling said pivot structure to pivot freely and eccentrically about said pivot shaft of said eccentric adjusting member.