Latch pin assembly for folding wing tip system

Patent metadata

Field	Value
Publication number	US-9914524-B2
Application number	US-201514824858-A
Country	US
Kind code	B2
Filing date	Aug 12, 2015
Priority date	Jan 19, 2015
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A folding wing tip system of an aircraft includes a latch pin actuator having a primary mechanical lock and a secondary hydraulic lock. The mechanical lock may include a lock cam movable between a lock position, in which the lock cam engages the latch pin, and an unlock position, in which the lock cam is disengaged from the latch pin, and a first lock actuator mechanically coupled to the lock cam and configured to provide a bias force pushing the lock cam toward the lock position. The hydraulic lock may be disposed in an unlatching hydraulic line and has an initial state, in which fluid flow through the unlatching hydraulic line is blocked thereby to hold the latch pin in the latched position, and an open state, in which fluid flow through the unlatching hydraulic line is permitted thereby to permit refraction of the latch pin to the unlatched position.

First claim

What is claimed is:

1. A latch pin assembly for use with a hydraulic fluid source, the latch pin assembly comprising:
a piston including a piston head;
a latch pin enclosing the piston head and defining an inner chamber, the piston head separating the inner chamber into an extend chamber and a retract chamber, the latch pin including a latch surface;
a latching hydraulic line fluidly communicating between the extend chamber and the hydraulic fluid source;
an unlatching hydraulic line fluidly communicating between the retract chamber and the hydraulic fluid source;
a lock cam movable between a lock position, in which the lock cam engages the latch surface of the latch pin, and an unlock position, in which the lock cam is disengaged from the latch surface of the latch pin;
a first lock actuator mechanically coupled to the lock cam and configured to provide a bias force pushing the lock cam toward the lock position;
a second lock including a hydraulic lock disposed in the latching hydraulic line and having an initial state, in which fluid flow is blocked from exiting the extend chamber through the latching hydraulic line, and an open state, in which fluid flow is permitted from the extend chamber through the latching hydraulic line.

2. The latch pin assembly of claim 1 , in which the first lock actuator comprises a spring.

3. The latch pin assembly of claim 1 , in which the hydraulic lock comprises a check valve.

4. The latch pin assembly of claim 1 , in which the aircraft further comprises a fixed wing portion including a first set of lugs and an unfixed wing portion including a second set of lugs, and in which the latch pin is sized for insertion through the first and second sets of lugs.

5. The latch pin assembly of claim 1 , further comprising an unlocking actuator operably coupled to the lock cam and configured to provide an unlock force counteracting the bias force of the first lock actuator.

6. The latch pin assembly of claim 5 , in which the unlocking actuator comprises a hydraulic actuator, the latch pin assembly further including an unlocking hydraulic line fluidly communicating between the hydraulic actuator and the hydraulic fluid source.

7. The latch pin assembly of claim 6 , in which the hydraulic actuator is movable between a normal position, in which the unlock force is less than the bias force, and an actuated position, in which the unlock force is greater than the bias force.

8. The latch pin assembly of claim 6 , further comprising a sequencing valve mechanically coupled to the hydraulic actuator and fluidly coupled to the hydraulic lock by a pilot line, the sequencing valve being movable between a blocking state when the hydraulic actuator is in the normal position to prevent fluid flow through the pilot line, and a free state when the hydraulic actuator is in the actuated position to permit fluid flow through the pilot line.

9. The latch pin assembly of claim 8 , in which the hydraulic lock is configured to move to the open state when hydraulic fluid flows through the pilot line.

10. A locking assembly for a latch pin assembly having a piston with a piston head, a latch pin enclosing the piston head and defining an inner chamber, the piston head separating the inner chamber into an extend chamber and a retract chamber, the latch pin including a latch surface, a latching hydraulic line fluidly communicating between the extend chamber and a hydraulic fluid source, and an unlatching hydraulic line fluidly communicating between the retract chamber and the hydraulic fluid source, the locking assembly comprising:
a first lock including:
a lock cam movable between a lock position, in which the lock cam engages the latch surface of the latch pin, and an unlock position, in which the lock cam is disengaged from the latch surface of the latch pin; and
a first lock actuator mechanically coupled to the lock cam and configured to provide a bias force pushing the lock cam toward the lock position; and

a second lock including:
a hydraulic lock disposed in the latching hydraulic line and having an initial state, in which fluid flow is blocked from exiting the extend chamber through the latching hydraulic line, and an open state, in which fluid flow is permitted from the extend chamber through the latching hydraulic line is permitted.

11. The locking assembly of claim 10 , in which the hydraulic lock comprises a check valve.

12. The locking assembly of claim 10 , further comprising an unlocking actuator operably coupled to the lock cam and configured to provide an unlock force counteracting the bias force of the first lock actuator.

13. The locking assembly of claim 12 , in which the unlocking actuator comprises a hydraulic actuator and an unlocking hydraulic line fluidly communicating between the hydraulic actuator and the hydraulic fluid source.

14. The locking assembly of claim 13 , in which the hydraulic actuator is movable between a normal position, in which the unlock force is less than the bias force, and an actuated position, in which the unlock force is greater than the bias force.

15. The locking assembly of claim 13 , further comprising a sequencing valve mechanically coupled to the hydraulic actuator and fluidly coupled to the hydraulic lock by a pilot line, the sequencing valve being movable between a blocking state when the hydraulic actuator is in the normal position to prevent fluid flow through the pilot line, and a free state when the hydraulic actuator is in the actuated position to permit fluid flow through the pilot line.

16. The locking assembly of claim 15 , in which the hydraulic lock is configured to move to the open state when hydraulic fluid flows through the pilot line.

17. A method of securing a latch pin in a latched position, the latch pin being provided in a latch pin assembly provided on an aircraft having a hydraulic fluid source, the method comprising:
mechanically locking the latch pin in the latched position by engaging a lock cam with a bias force to move the lock cam to a lock position, wherein the lock cam in the locked position mechanically engages the latch pin; and
hydraulically locking the latch pin in the latched position by preventing fluid flow from exiting an extend chamber of the latch pin through a latching hydraulic line fluidly communicating between the hydraulic fluid source the an extend chamber.

18. The method of claim 17 , in which mechanically locking the latch pin comprises engaging the lock cam with a first lock configured to generate the bias force.

19. The method of claim 17 , wherein a check valve is disposed in the latching hydraulic line and has an initial state, in which fluid flow through the latching hydraulic line is blocked, and an open state, in which fluid flow through the latching hydraulic line is permitted, and in which hydraulically locking the latch pin comprises placing the check valve in the initial state.

20. The method of claim 17 , in which the latch pin includes a latch pin surface, and in which mechanically locking the latch pin comprises mechanically engaging the lock cam with the latch pin surface.

Assignees

• Boeing Co

Inventors

• Good Mark S
• Jokisch Charles E

Classifications

• F15B2211/329

  actuated by fluid pressure · CPC title

• F15B2211/72

  having locking means · CPC title

• B64C23/072

  the wing tip airfoil devices being moveable in their entirety · CPC title

• F15B15/261

  using positive interengagement, e.g. balls and grooves, for locking in the end positions · CPC title

• F15B2015/268

  Fluid supply for locking or release independent of actuator pressurisation · CPC title