Apparatus and method for controlling landing gear

Patent metadata

Field	Value
Publication number	US-10106248-B2
Application number	US-201414897101-A
Country	US
Kind code	B2
Filing date	Jun 12, 2014
Priority date	Jun 14, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A landing gear system includes landing gear, an uplock that is releasably engageable with the landing gear, an uplock hydraulic actuator operably connected to the uplock, a landing gear hydraulic actuator operatively connected to the landing gear, and a controller operatively connected to the uplock hydraulic actuator and the landing gear hydraulic actuator. In response to receipt of a command to deploy the landing gear, the controller actuates the uplock hydraulic actuator and the landing gear hydraulic actuator to the UP condition and then actuates the uplock hydraulic actuator and the landing gear actuator to the DOWN condition. An alternative embodiment incorporates a piloted check valve upstream of the landing gear hydraulic actuator. The piloted check valve delays operation of the landing gear hydraulic actuator until release of the landing gear by the uplock.

First claim

What is claimed is:

1. A landing gear system, comprising:
a landing gear movable between a stowed position and a deployed position;
a landing gear hydraulic actuator operably connected to the landing gear;
an uplock releasably engageable with the landing gear;
an uplock hydraulic actuator operably connected to the uplock;
a selector valve for causing selective pressurization of the landing gear hydraulic actuator and the uplock hydraulic actuator, the selector valve being connected to the landing gear hydraulic actuator by at least a first hydraulic line and being connected to the uplock hydraulic actuator by at least a second hydraulic line;
a piloted check valve positioned in the first hydraulic line between the selector valve and the landing gear hydraulic actuator;
a pilot line hydraulically connecting the second hydraulic line to the piloted check valve; and
a controller, wherein in response to receipt of a command to deploy the landing gear:
causing the selector valve to acquire an UP condition for actuating the landing gear hydraulic actuator to an UP condition, wherein the landing gear hydraulic actuator is held in the UP condition via the piloted check valve;
causing the selector valve to acquire a DOWN condition for actuating the landing gear hydraulic actuator to a DOWN condition; and
causing the piloted check valve to be released, thereby permitting the landing gear hydraulic actuator to acquire the DOWN condition.

2. The landing gear system of claim 1 , further comprising an uplock hydraulic actuator operably connected to the uplock, the selector valve operative for causing selective pressurization of the uplock hydraulic actuator.

3. The landing gear system of claim 2 , wherein when the selector valve is caused to acquire the DOWN condition, the uplock hydraulic actuator causes the uplock to disengage from the landing gear.

4. The landing gear system of claim 3 , wherein the piloted check valve delays the actuation of the landing gear hydraulic actuator to the DOWN condition by a time sufficient to allow the uplock hydraulic actuator to cause the uplock to disengage from the landing gear.

5. The landing gear system of claim 3 , wherein when the selector valve is caused to acquire the UP condition, the uplock hydraulic actuator is also actuated to an UP condition.

6. The landing gear system of claim 2 , wherein the first and second hydraulic lines connect the uplock hydraulic actuator and the landing gear hydraulic actuator to one another.

7. The landing gear system of claim 6 , wherein the first hydraulic line connected to the landing gear hydraulic actuator is larger than the second hydraulic line connected to the uplock hydraulic actuator.

8. The landing gear system of claim 1 , wherein the landing gear is one of a right side landing gear, a left side landing gear and a nose landing gear.

9. The landing gear system of claim 1 , wherein the piloted check valve is caused to be released via application of a pilot pressure.

10. The landing gear system of claim 1 , wherein when the controller actuates the selector valve to the UP condition for actuating the landing gear hydraulic actuator to an UP condition, a weight of the landing gear on the uplock is reduced.

11. The landing gear system of claim 1 , wherein when the controller actuates the selector valve to the UP condition for actuating the landing gear hydraulic actuator to an UP condition, a weight of the landing gear on the uplock is removed.

12. A method of operating a landing gear system that comprises landing gear, a landing gear hydraulic actuator operably connected to the landing gear, an uplock releasably engageable with the landing gear, an uplock hydraulic actuator operably connected to the uplock, a selector valve for causing selective pressurization of the landing gear hydraulic actuator and the uplock hydraulic actuator, the selector valve being connected to the landing gear hydraulic actuator by at least a first hydraulic line and being connected to the uplock hydraulic actuator by at least a second hydraulic line, a piloted check valve positioned in the first hydraulic line prior to the landing gear hydraulic actuator, a pilot line hydraulically connecting the second hydraulic line to the piloted check valve, and a controller operably connected to the landing gear hydraulic actuator, the uplock hydraulic actuator and the piloted check valve, the method comprising:
receiving a landing gear deployment signal by the controller;
actuating the landing gear hydraulic actuator to an UP condition to remove at least some of the weight of the landing gear from the uplock;
causing the landing gear hydraulic actuator to be held in the UP condition via the piloted check valve;
actuating the uplock hydraulic actuator to a DOWN condition to disengage the uplock from the landing gear; and
releasing the piloted check valve, thereby permitting the landing gear hydraulic actuator to be actuated to the DOWN condition.

13. The method of claim 12 , further comprising:
causing the selector valve to acquire an UP condition for actuating the landing gear hydraulic actuator to an UP condition, wherein the landing gear hydraulic actuator is held in the UP condition via the piloted check valve.

14. The method of claim 13 , further comprising:
in response to receipt of the landing gear deployment signal by the controller, causing the selector valve to acquire the UP condition for actuating both the uplock hydraulic actuator and the landing gear hydraulic actuator to the UP condition.

15. The method of claim 13 , further comprising:
causing the selector valve to acquire a DOWN condition for actuating the uplock hydraulic actuator to the DOWN condition.

16. The method of claim 15 , further comprising:
causing the selector valve to acquire a DOWN condition for actuating both the uplock hydraulic actuator to the DOWN condition and the landing gear hydraulic actuator to the DOWN condition.

17. The method of claim 16 , wherein the piloted check valve delays the actuation of the landing gear hydraulic actuator to the DOWN condition by a time sufficient to allow the uplock hydraulic actuator to cause the uplock to disengage from the landing gear.

18. The method of claim 12 , wherein the first and second hydraulic lines connect the uplock hydraulic actuator and the landing gear hydraulic actuator to one another.

19. The method of claim 18 , wherein the first hydraulic line connected to the landing gear hydraulic actuator is larger than the hydraulic piping connected to the uplock hydraulic actuator.

20. The method of claim 12 , further comprising applying a pilot pressure to the piloted check valve to cause release of the piloted check valve.

Assignees

• Bombardier Inc
• Learjet Inc
• Learjet

Inventors

• Boucher Frederic
• Ribas Clovis S

Classifications

• B64C25/26

  Control or locking systems therefor · CPC title

• B64C25/22 Primary

  fluid · CPC title