Folding Proprotor Gimbal Lock and Blade Lock Mechanism

• US 20160152329A1
• Filed: 12/02/2015
• Published: 06/02/2016
• Est. Priority Date: 12/02/2014
• Status: Active Grant

• Current Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Tzeng, Chyau-Song, Schank, Troy Cyril
• Granted Patent: US 10,336,447 B2
• Time in Patent Office: Days
• CPC Class Codes: B64C 11/28 Collapsible or foldable blades
• CPC Class Codes: B64C 27/30 with provision for reducing drag of inoperative rotor
• CPC Class Codes: B64C 29/0033 the propellers being tiltable relative to the fuselage

Abstract

A gimbal lock mechanism for a rotor hub can include a cam member having a cuff lock lobe and a gimbal lock lobe. The cam member is configured so that rotation can cause the first cuff lobe to become adjacent to the root end of the rotor blade and at the same time causes the gimbal lock lobe to become adjacent to a gimbal so as to inhibit gimbaling of the gimbal. A first moveable pin can be located on the root end portion of the rotor blade and inserted into the cuff lock lobe to prevent pitch change of the rotor blade.

Claims

1. A gimbal lock mechanism for a rotor hub, the gimbal lock mechanism comprising:

a cam member having a cuff lock lobe and a gimbal lock lobe, the cam member rotatable relative to a housing;

a rotor blade having a root end portion;

a first moveable pin located on the root end portion of the rotor blade; and

an aperture located in the cuff lock lobe;

wherein the cam member is configured so that rotation can cause the first cuff lobe to become adjacent to the root end of the rotor blade and at the same time causes the gimbal lock lobe to become adjacent to a gimbal and inhibit gimbaling of the gimbal.

2. The gimbal lock mechanism according to claim 1, wherein an insertion of the first translatable pin into the aperture of the cuff lock lobe prevents a pitch change of the rotor blade.

3. The gimbal lock mechanism according to claim 1, further comprising:

a first actuator coupled to the cam member.

4. The gimbal lock mechanism according to claim 3, wherein the first actuator is coupled to the cam member with a ring member and a linkage.

5. The gimbal lock mechanism according to claim 1, further comprising:

a second actuator coupled to the first moveable pin.

6. The gimbal lock mechanism according to claim 1, further comprising:

a rotor mast;

wherein the housing is concentric with the rotor mast.

7. The gimbal lock mechanism according to claim 1, further comprising:

wherein the cam member is configured to rotate about a cam axis that is parallel to a rotor mast axis of rotation.

8. The gimbal lock mechanism according to claim 1, further comprising:

a pitch horn rotatably coupled to the root end portion of the rotor blade;

a second moveable pin integral to the first moveable pin;

wherein insertion of the first moveable pin into the aperture of the cuff lock lobe results in the second moveable pin being removed from a second aperture in the pitch horn which frees the pitch horn to rotate about a crank axis of rotation during a folding of the rotor blade.

9. The gimbal lock mechanism according to claim 1, further comprising:

a pitch horn rotatably coupled to the root end portion of the rotor blade;

a second moveable pin integral to the first moveable pin;

wherein insertion of the first moveable pin into the aperture of the cuff lock lobe results in the second moveable pin being removed from a second aperture in the pitch horn such that a raising of the swashplate causes the pitch horn to rotate about a crank axis of rotation and fold the rotor blade.

10. An aircraft comprising:

a rotor mast;

a rotor blade;

a pitch horn coupled to a root end of the rotor blade;

a cam member having a cuff lock lobe and a gimbal lock lobe;

a moveable pin located on the root end portion of the rotor blade; and

an aperture located in the cuff lock lobe;

wherein the cam member is configured so that actuation of the cam member about a first direction can cause the first cuff lobe to travel away from the root end portion of the rotor blade to prevent interference of the cuff lock lobe and the root end of the rotor blade during operation of the aircraft.

11. The aircraft according to claim 10, wherein the cam member configured so that actuation of the cam member about the first direction also causes the gimbal lock lobe to travel away from a gimbal member so that the gimbal is not prevented from flapping by the gimbal lock lobe

12. The aircraft according to claim 10, wherein the cam member is configured so that actuation of the cam member about a second direction causes the first cuff lobe to become adjacent to the root end of the rotor blade and at the same time cause the gimbal lock lobe to become adjacent to a gimbal and inhibit gimbaling of the gimbal.

13. The aircraft according to claim 10, wherein the pitch horn is coupled to the root end of the rotor blade with a spindle and the moveable pin.

14. The aircraft according to claim 13, wherein removal of the moveable pin from the pitch horn allows the pitch horn to selectively rotate about the spindle.

15. A method of converting an aircraft from a proprotor mode to an airplane mode, the method comprising:

actuating a rotor blade to a feathered position with a swashplate;

removing a first pin from a pitch horn which allows the pitch horn to rotate about a crank axis of rotation;

inserting a second pin into a cuff lock lobe which prevents a pitch change of the rotor blade; and

actuating the swashplate which causes the rotor blade to fold.

16. The method according to claim 15, further comprising:

actuating a cam member, the cam member having the cuff lock lobe and a gimbal lock lobe.

17. The method according to claim 16, wherein the gimbal lock lobe physically inhibits a gimbal from flapping.