US 6,981,439 B2
Redundant flow control for hydraulic actuator systems
Kenneth E. Hart, Simi Valley, Calif. (US)
Assigned to HR Textron, Inc., Santa Clarita, Calif. (US)
Filed on Dec. 23, 2003, as Appl. No. 10/746,033.
Claims priority of provisional application 60/497284, filed on Aug. 22, 2003.
Prior Publication US 2005/0132877 A1, Jun. 23, 2005
Int. Cl. F15B 13/00 (2006.01)
U.S. Cl. 91—509 38 Claims
OG exemplary drawing
 
1. A hydraulic flow control system for use with a tandem hydraulic actuator, said system comprising:
a flow control valve assembly including a sleeve, a bypass control spool slidingly disposed within said sleeve, and a primary control spool slidingly disposed within said bypass control spool;
a bypass-shutoff valve hydraulically coupled to a supply line, a return line, a pressure control line, an actuator extend line and an actuator retract line; and
a restrictor-check valve assembly, wherein said restrictor-check valve assembly is hydraulically coupled to said bypass-shutoff valve and said supply line.