Negative rate shaping torque capsule Document Type and Number: United States Patent 7165531 Abstract: A negative rate shaping torque capsule is provided that effectively reduces torque rise of the engine. The device is part of the mechanical governor and allows fuel control rack position to decrease as engine speed decreases, thus reducing the amount of fuel delivered and reducing torque rise. The device works by the addition of a pivot arm to the existing main governor arm. One end of the pivot arm is pinned to the governor arm, and a roller is pinned to the opposite end. This roller bears on the fuel rack, maintaining rack position. An additional roller is pinned to the side of the pivot arm and bears on the tension arm. The travel of the pivot arm relative to the governor arm is limited in one direction by a physical stop, and in the other direction by a torque capsule (TC) spring. The TC spring is fixed to the governor arm and bears on the pivot arm roller opposite the tension arm. The TC spring holds the pivot arm roller against the tension arm. As engine speed increases the increased flyweight force causes an increase in the force of the pivot arm roller against the tension arm. At some point this force overcomes the preload on the TC spring causing the pivot arm to lift off its physical stop effectively causing the governor arm to bend at the joint where the pivot arm is pinned to the governor arm, in turn causing the rack roller end of the pivot arm to move in a direction of increasing rack travel. As engine speed continues to increase the rack roller continues to increase rack travel until the flyweight force overcomes the main governor spring and rack travel begins to decrease as the engine follows the governor droop curve up to the high idle speed.