Pressure switching valve for multiple redundant electrohydraulic servo valve systems

A switching valve for switching between a primary electrohydraulic servo valve and a backup electrohydraulic servo valve of at least one control system, the servo valves operatively connected to at least one actuator for controlling at least one engine parameter, the servo valves receiving pressurized fluid from an inlet and discharging fluid to an outlet, the switching valve comprising:

• a transfer valve assembly including a valve body positioned within a valve sleeve;
• the transfer valve assembly interposed between the servo valves and the inlet and outlet to regulate communication between the servo valves and the inlet and outlet;
• the valve body moveable within the valve sleeve to a first position linking the primary servo valve to the inlet and outlet;
• and
• the valve body moveable within the valve sleeve to a second position linking the backup servo valve to the inlet and outlet.

A switching system for an engine having redundant control components for multiple control systems, the switching system comprising in combination:

• an inlet for supplying pressurized fuel;
• an outlet for draining fuel;
• a first primary electrohydraulic servo valve operatively connected to a fuel metering valve to regulate fuel flow;
• a first backup electrohydraulic servo valve operatively connected to the fuel metering valve;
• a second primary electrohydraulic servo valve operatively connected to an actuator to control an engine parameter;
• a second backup electrohydraulic servo valve operatively connected to the actuator;
• and
• a transfer valve positioned between the servo valves and the inlet and outlet, the transfer valve operable between a first position supplying the first and second primary servo valves with fuel and a second position supplying the first and second backup servo valves with fuel.