US Patent 10337776 Refrigeration system having valves and valve control actuators

A refrigeration system having an airflow supply system having a supply duct providing cooled air from a refrigeration unit to a plurality of galley carts received in one or more cart compartments includes a plurality of valves coupled in the airflow supply system for controlling flows of the cooled air to the plurality of galley carts in the one or more cart compartments, where each valve of the plurality of valves is associated with a respective galley cart. The refrigeration system includes a plurality of primary valve control actuators each coupled to a respective valve and configured to reposition the respective valve during a first mode of operation. The refrigeration system includes a backup valve control actuator coupled to at least one of the plurality of valves and configured to reposition the at least one of the plurality of valves during a second mode of operation.