Wing fold actuator system for aircraft

A wing fold actuator system for use in an aircraft having an outboard wing section with a latch pin unit for releasably locking the outboard wing section to an inboard wing section said actuator system comprising:

• an electrohydraulic actuator connected between the inboard and outboard wing sections, said electrohydraulic actuator including a driven member for displacing the outboard wing section between the deployed and folded positions;
• said electrohydraulic actuator further including hydraulic drive means and electric motor drive means alternatively operable for reversible power drive displacement of said driven member, said electric motor drive means including a rotatable output shaft connected to said driven member, said output shaft being rotatable back-driven by said driven member upon operation of said hydraulic drive means to displace said driven member;
• a brake unit for preventing displacement of said driven member upon interruption of power drive displacement thereof, said brake unit including a brake member carried on said output shaft for rotation therewith, a friction member, means for engaging said brake and friction members to prevent rotation of said output shaft in the absence of operation of one of said drive members, and means for disengaging said brake and friction members to permit rotation of said output shaft during operation of one of said drive members for power drive displacement of said drive member;
• and
• wherein said latch pin unit includes an extensible latch pin, and further including electrohydraulic means for displacing said latch pin between extended and retracted positions.

A wing fold actuator system for use in an aircraft having an outboard wing section with a latch pin unit for releasably locking the outboard wing section to an inboard wing section said actuator system comprising:

• an electrohydraulic actuator connected between the inboard and outboard wing sections, said electrohydraulic actuator including a driven member for displacing the outboard wing section between the deployed and folded positions;
• said electrohydraulic actuator further including hydraulic drive means and electric motor drive means alternatively operable for reversible power drive displacement of said driven member, said electric motor drive means including a rotatable output shaft connected to said driven member, said output shaft being rotatable back-driven by said driven member upon operation of said hydraulic drive means to displace said driven member;
• a brake unit for preventing displacement of said driven member upon interruption of power drive displacement thereof, said brake unit including a brake member carried on said output shaft for rotation therewith, a friction member, means for engaging said brake and friction members to prevent rotation of said output shaft in the absence of operation of one of said drive members, and means for disengaging said brake and friction members to permit rotation of said output shaft during operation of one of said drive members for power drive displacement of said drive member;
• and
• wherein said latch pin unit includes a latch pin movable along a longitudinal axis of said pin between extended and retracted positions, and means for rotating said latch pin about said axis during movement between said extended and retracted positions.

A wing fold actuator system for use in an aircraft having an outboard wing section connected to an inboard wing section for folding movement between a deployed position and a folded position, said actuator system comprising:

• an hydraulic power cylinder connected to one of the inboard and outboard wing sections;
• a power piston mounted within said power cylinder;
• a ram carried by said power piston and projecting from said power cylinder and being connected to the other of said inboard and outboard wing sections;
• an electric drive motor having a rotatable output shaft;
• transmission means connected between said power piston and said output shaft for reversibly driving said output shaft in response to translation of said power piston within said power cylinder;
• a brake member carried on said output shaft for rotation therewith;
• a nonrotational friction member;
• spring means for normally displacing said friction member into braking engagement with said brake member to normally prevent rotation of said output shaft and thereby also prevent translation of said power piston within said power cylinder;
• hydraulic drive means for supplying hydraulic fluid under pressure to said power cylinder for translating said power piston therein, said hydraulic drive means including hydraulic brake release means for displacing said friction member out of braking engagement with said brake member during supply of the hydraulic fluid under pressure to said power cylinder, thereby permitting rotation of said output shaft;
• and
• electric drive means for driving said electric motor to rotatably drive said output shaft and thereby translate said power piston within said power cylinder, said electric drive means including electric brake release means for displacing said friction member out of braking engagement with said brake member during driving operation of said electric motor thereby permitting rotation of said output shaft;
• said hydraulic and electric brake release means permitting spring-loaded re-engagement of said brake and friction members upon respective operational interruption of said hydraulic and electric drive means.