Hydraulic actuation system for aircraft control surfaces

An actuation system for positioning a control surface operably mounted on an aircraft wing, said control surface having upper and lower skin surfaces and a spar member disposed between said upper and lower skin surfaces of said control surface at the operable mounting of said control surface with said aircraft wing, and said aircraft wing having upper and lower skin surfaces and a spar member disposed between said upper and lower skin surfaces of said aircraft wing at the operable mounting of said aircraft wing with said control surface, said actuation system comprising:

• a cylinder block disposed in said aircraft wing forward of said aircraft wing spar member and including an upper piston cylinder disposed contiguous to said aircraft wing upper skin surface and a second piston cylinder disposed contiguous to said aircraft wing lower skin surface, each of said upper and said lower piston cylinders having a piston rod extending towards said control surface with each of said piston rods having a free end with a hinge point;
• said control surface spar having upper and lower pivot points disposed towards said aircraft wing spar, said upper and said lower pivot points spaced apart on said control surface spar;
• an upper actuator link operably connecting said hinge point of said upper piston rod with said upper pivot point of said control surface spar;
• a lower actuator link operably connecting said hinge point of said lower piston rod with said lower pivot point of said control surface spar;
• and
• means to extend and retract said upper and said lower piston rods whereby extension of said upper piston rod will rotate said control surface about said lower pivot point and extension of said lower piston rod will rotate said control surface about said upper pivot point.

An actuation system for positioning an elevon operably mounted on an aircraft wing, said elevon having upper and lower skin surfaces and a spar member disposed between said upper and lower skin surfaces of said elevon at the operable mounting of said elevon with said aircraft wing, and said aircraft wing having upper and lower skin surfaces and a spar member disposed between said upper and lower skin surfaces of said aircraft wing at the operable mounting of said aircraft wing with said elevon, said actuation system comprising:

• a cylinder block disposed in said aircraft wing between said aircraft wing upper and lower skin surfaces and forward of said aircraft wing spar member and including an upper piston cylinder disposed contiguous to said aircraft wing upper skin surface and a second piston cylinder disposed contiguous to said aircraft wing lower skin surface and parallel to said upper piston cylinder, each of said upper and said lower piston cylinders having a piston rod extending towards said elevon with each of said piston rods having a free end with a hinge point;
• said elevon spar having upper and lower pivot points disposed towards said aircraft wing spar, said upper and said lower pivot points spaced apart with said upper pivot point disposed near said elevon upper skin surface and said lower pivot point disposed near said elevon lower skin surface;
• an upper actuator link operably connecting said hinge point of said upper piston rod with said upper pivot point of said elevon spar;
• a lower actuator link operably connecting said hinge point of said lower piston rod with said lower pivot point of said elevon spar;
• and
• means to extend and retract said upper and said lower piston rods including pressure ports at each of said upper and said lower piston cylinders and means to alternately supply hydraulic pressure to said pressure ports, extension of said upper piston rod rotating said elevon about said lower pivot point and extension of said lower piston rod rotating said elevon about said upper pivot point.