US Patent 9664409 HVAC damper system

An illustrative damper system includes a damper blade that is configured to be positioned within a duct, such as a bypass duct of an HVAC system. A shaft is in communication with the damper blade, and an actuator or force adjustment mechanism is in communication with the shaft. The actuator or force adjustment mechanism may include a housing and a spring therein, where the spring is in communication with the shaft. The shaft, the damper blade, and the spring may be configured such that the shaft may affect movement of the damper blade about a rotation axis offset from a diametrical axis of the damper blade.