Air-ground detection system for semi-levered landing gear

• US 9,499,280 B2
• Filed: 09/07/2014
• Issued: 11/22/2016
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Mellor, Mitchell Loren Ray
• Primary Examiner(s): Dinh, Tien
• Assistant Examiner(s): RODRIGUEZ, VICENTE M
• Application Number:
  US14/479,319
• Publication Number:
  US 20150266592A1
• Time in Patent Office: 807 Days
• Field of Search: 244/100.R, 73/17.9
• US Class Current: 1/1
• CPC Class Codes: B64C 2025/008 Comprising means for modifying their length, e.g. for kneeling, for jumping, or for leveling the aircraft
• CPC Class Codes: B64C 2025/345 Multi-wheel bogies having one or more steering axes
• CPC Class Codes: B64C 25/00 Alighting gear air-cushion alighting gear B60V3/08
• CPC Class Codes: B64C 25/36 Arrangements or adaptations of wheels, tyres or axles in general
• CPC Class Codes: B64C 25/62 Spring shock-absorbers; Springs
• CPC Class Codes: B64D 45/06 mechanical

Abstract

A method and apparatus for air-ground detection. A truck beam of a semi-levered landing gear is mounted on a pivot pin. The truck beam is configured to rotate about the pivot pin between a toes down position and a toes up position. A positioning mechanism is connected to a locking mechanism that secures an angle of the truck beam in the toes up position. The locking mechanism is secured in a steady state and configured to change from the steady state to a locked state in response to an initial ground contact. A sensor is connected to the locking mechanism. The sensor is configured to detect a change from the steady state to the locked state.

Claims

1. A method using an air-ground detection system comprising a truck beam of a semi-levered landing gear mounted on a pivot point, a positioning mechanism connected to a semi-levered linkage assembly that secures an angle of the truck beam in a toes up position, the semi-levered linkage assembly configured to change from a secured, steady state to a locked state in response to initial ground contact, and the air-ground detection system further comprising a sensor connected to the semi-levered linkage assembly, the semi-levered linkage assembly comprising a compression spring and a tension spring, the method comprising:

holding, using the compression spring, the semi-levered linkage assembly in a steady state while a tension load on the semi-levered linkage assembly is less than a pre-determined tension load value;

holding, using the tension spring, the semi-levered linkage assembly in the steady state while a first compression load on the semi-levered linkage assembly is less than a pre-determined compression load value;

permitting, using the tension spring, the semi-levered linkage assembly to fold closed while under a second compression load exceeding the pre-determined compression load value; and

sensing, using the sensor, a change of the semi-levered linkage assembly from a steady state to a locked state based on a change in orientation of the tension spring.

2. The method of claim 1 further comprising:

sending, using the sensor, a signal indicating an occurrence of initial ground contact in response to sensing the change.

3. The method of claim 1, wherein the semi-levered linkage assembly further comprises a locking mechanism configured to secure the angle of the truck beam in the toes-up position, and wherein the method further comprises:

changing the locking mechanism from the steady state to the locked state in response to an initial ground contact.

4. The method of claim 3, wherein the locking mechanism further comprises a compression spring, and wherein the method further comprises:

holding the locking mechanism in the steady state under a tension load less than the pre-determined tension load value.

5. The method of claim 4, wherein the locking mechanism further comprises a first link and a second link, wherein the compression spring is connected to the first link, wherein the compression spring is restrained in a pre-loaded position, and wherein the method further comprises:

compressing the locking mechanism beyond the steady state by applying to the locking mechanism a tension load greater than the pre-determined tension load value; and

the compression spring of the locking mechanism preventing force from being applied to the second link.

6. The method of claim 3 further comprising a stop connected to the locking mechanism and wherein the method further comprises:

the stop preventing rotation of the truck beam at a pre-determined degree of rotation in response to a change from the steady state to the locked state.

7. The method of claim 3, wherein the semi-levered linkage assembly further comprises a pivot pin to which the truck beam is mounted, and wherein the method further comprises:

rotating the truck beam about the pivot pin between a toes up position prior to landing a toes down position after an initial ground contact.