Patent ID: 7155144

Claim:
A tensioning device for minimizing tension variations in a moveable endless belt having a desired tension setting and configured to be mounted for rotation about rollers mounted to a frame, the tensioning device comprising: a moveable member for mounting transversely to a direction of movement of the moveable endless belt said moveable member being movable into contact with the moveable endless belt; a force exerting mechanism comprising a first moment arm, a second moment arm and a biaser, the first moment arm being coupled at a first end to the frame for pivotal movement of the first moment arm about a pivot fixed relative to the frame and a second end coupled to a first end of the second moment arm, the second moment arm having a second end coupled to the moveable member and being coupled at the first end for pivotal movement relative to the first moment arm about a moveable pivot coupling the first and second moment arms and the biaser being coupled to the frame and the moveable pivot to bias the moveable pivot to urge the second end of the second moment arm away from the fixed pivot thereby urging the moveable member into contact with the moveable endless belt, thereby tensioning the moveable endless belt and minimizing variations from the desired tension setting of the moveable endless belt.