Pitch-fold lock

Patent metadata

Field	Value
Publication number	US-12214860-B2
Application number	US-202218059002-A
Country	US
Kind code	B2
Filing date	Nov 28, 2022
Priority date	May 20, 2020
Publication date	Feb 4, 2025
Grant date	Feb 4, 2025

Abstract

Embodiments are directed to a blade lock comprising a fold lock adapted to prevent folding of a rotor blade in a fold-lock position and to allow folding of the rotor blade in a pitch-lock position. The blade lock further comprises a pitch lock adapted to allow pitch movement of a rotor blade in a fold-lock position and to prevent pitch movement of the rotor blade in the pitch-lock position. A spring-loaded link pivotally connects both the fold lock and the pitch lock and is adapted to provide passive, overcenter locking in the fold-lock position. An actuator is coupled to the pitch lock and is adapted to move the pitch lock and the fold lock between the fold-lock and pitch-lock positions.

First claim

What is claimed is:

1. A blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade, the blade lock comprising:
a fold lock adapted to prevent folding of a rotor blade in a fold-lock position and to allow folding of the rotor blade in a pitch-lock position;
a pitch lock adapted to allow pitch movement of a rotor blade in a fold-lock position and to prevent pitch movement of the rotor blade in the pitch-lock position;
a spring-loaded link pivotally connected to both the fold lock and the pitch lock and adapted to provide passive, overcenter locking in the fold-lock position;
an actuator coupled to the pitch lock and adapted to move the pitch lock and the fold lock between the fold-lock and pitch-lock positions, wherein the actuator is a linear actuator having an actuator shaft that is coupled to the pitch lock; and
an attachment point on the pitch lock, the attachment point separated from a pivot axis of the pitch lock by a specified distance, wherein both the spring-loaded link and the actuator are pivotally connected to the attachment point.

2. The blade lock of claim 1 , further comprising:
a blade-fold link coupled to the rotor blade, wherein the fold lock enables and disables the folding degree of freedom by unlocking and locking the blade-fold link.

3. The blade lock of claim 1 , further comprising:
a rotor cuff tab and a blade-stop tab, wherein the pitch lock enables and disables the pitching degree of freedom by unlocking and locking the rotor cuff tab and the blade-stop tab together.

4. A blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade, the blade lock comprising:
a fold lock adapted to prevent folding of a rotor blade in a fold-lock position and to allow folding of the rotor blade in a pitch-lock position;
a pitch lock adapted to allow pitch movement of a rotor blade in a fold-lock position and to prevent pitch movement of the rotor blade in the pitch-lock position;
a spring-loaded link pivotally connected to both the fold lock and the pitch lock and adapted to provide passive, overcenter locking in the fold-lock position;
an actuator coupled to the pitch lock and adapted to move the pitch lock and the fold lock between the fold-lock and pitch-lock positions, wherein the actuator is a linear actuator having an actuator shaft that is coupled to the pitch lock;
a first attachment point on the pitch lock, the first attachment point separated from a pivot axis of the pitch lock by a first distance; and
a second attachment point on the pitch lock, the second attachment point separated from the pivot axis of the pitch lock by a second distance that is shorter than the first distance;
wherein the spring-loaded link is pivotally connected to the first attachment point and the actuator is pivotally connected to the second attachment point.

5. The blade lock of claim 4 , further comprising:
a blade-fold link coupled to the rotor blade, wherein the fold lock enables and disables the folding degree of freedom by unlocking and locking the blade-fold link.

6. The blade lock of claim 4 , further comprising:
a rotor cuff tab and a blade-stop tab, wherein the pitch lock enables and disables the pitching degree of freedom by unlocking and locking the rotor cuff tab and the blade-stop tab together.

7. A blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade, the blade lock comprising:
a fold lock adapted to prevent folding of a rotor blade in a fold-lock position and to allow folding of the rotor blade in a pitch-lock position;
a pitch lock adapted to allow pitch movement of a rotor blade in a fold-lock position and to prevent pitch movement of the rotor blade in the pitch-lock position;
a spring-loaded link pivotally connected to both the fold lock and the pitch lock and adapted to provide passive, overcenter locking in the fold-lock position;
an actuator coupled to the pitch lock and adapted to move the pitch lock and the fold lock between the fold-lock and pitch-lock positions, wherein the actuator is a linear actuator having an actuator shaft that is coupled to the pitch lock;
a first attachment point on the pitch lock, the first attachment point separated from a pivot axis of the pitch lock by a first distance; and
a second attachment point on the pitch lock, the second attachment point separated from the pivot axis of the pitch lock by a second distance that is longer than the first distance;
wherein the spring-loaded link is pivotally connected to the first attachment point and the actuator is pivotally connected to the second attachment point.

8. The blade lock of claim 7 , further comprising:
a blade-fold link coupled to the rotor blade, wherein the fold lock enables and disables the folding degree of freedom by unlocking and locking the blade-fold link.

9. The blade lock of claim 7 , further comprising:
a rotor cuff tab and a blade-stop tab, wherein the pitch lock enables and disables the pitching degree of freedom by unlocking and locking the rotor cuff tab and the blade-stop tab together.

Assignees

• Textron Innovations Inc

Inventors

• Cravener Kyle Thomas
• Maresh Andrew Ryan
• Atkins Brady Garrett
• Schulte Kynn J
• Schank Troy

Classifications

• B64C11/065

  variable only when stationary · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• B64C11/06

  for variable-pitch blades · CPC title

• B64C11/28 Primary

  Collapsible or foldable blades · CPC title