Patent ID: 11891959
Assignee: ROLLS-ROYCE PLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 9:
10. The fuel control system of claim 9, wherein, upon loss of electrical power to the stage actuating unit, the movable member moves to a neutral position between the first end position and the second end position, such that each of the first and second chamber ports is open, wherein, upon loss of electrical power to the stage actuating unit when the movable member is in the first end position, the movable member moves to the neutral position from the first end position, and wherein, upon the movement of the movable member from the first end position to the neutral position, the fluid pressure within the first end chamber tends to equalize with the fluid pressure within the second end chamber, such that the spool of the second stage unit moves to the second spool position over the predetermined time duration and the valve member of the PRSOV moves to the closed position after the predetermined time duration.