Patent ID: 8693933

Claim:
An endless belt assembly comprising: one or more rollers disposed parallel to each other, each being rotatable around a rotational axis thereof; an endless belt looped for rotation around the rollers; and a belt tracking mechanism disposed on at least one side of the endless belt assembly to prevent lateral displacement of the endless belt during rotation, the belt tracking mechanism including: an annular recess perimetrically formed on a longitudinal end face of the roller; an annular flange disposed in the annular recess to rotate freely with respect to the roller; and a circumferential rib extending along a side edge of an interior circumferential surface of the endless belt to contact the annular flange upon lateral movement of the endless belt, the circumferential rib having an inner, beveled surface to face the annular flange, the beveled surface being inclined at a first acute angle relative to the rotational axis of the roller, so that the beveled surface is farthest from the annular flange at a free edge thereof separated from the endless belt, and closest to the annular flange at a fixed edge thereof connected to the endless belt, the annular flange having an outer, chamfered surface to face the circumferential rib, the chamfered surface being inclined at a second acute angle greater than the first acute angle relative to the rotational axis of the roller.