Advanced emergency collective actuator with friction pull-off and method for a helicopter

Patent metadata

Field	Value
Publication number	US-11820498-B2
Application number	US-202117176864-A
Country	US
Kind code	B2
Filing date	Feb 16, 2021
Priority date	May 21, 2015
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

An emergency collective actuator includes an actuator motor to produce an actuation force and an actuator linkage that directly engages a friction control lever that is pivotally supported on the collective stick of a helicopter to apply the actuation force directly to the friction control lever such that the actuation force initially disengages the friction control and then reduces the adjustable pitch toward a minimum collective pitch position. The actuator can include a clutch that slips to allow the pilot to overcome the actuation force and that slips responsive to an engagement of the friction control by the pilot, but otherwise the clutch co-rotates with the motor shaft to bias the adjustable pitch toward a minimum collective pitch position.

First claim

What is claimed is:

1. An apparatus for use with a helicopter including a rotor system having a main rotor with an adjustable pitch that is controlled at least in part by a pilot using a collective control and the collective control pivotally supports a friction control that is engageable by the pilot to selectively increase a control force that is required as a minimum to move the collective control, said apparatus comprising:
an actuator including a motor having an output shaft for rotation to change the adjustable pitch by exerting an actuation force;
a flexible cable that applies the actuation force to the friction control such that the actuation force initially disengages the friction control to decrease the control force and, thereafter, reduces the adjustable pitch toward a minimum collective pitch position; and
a control arrangement that is configured to receive a signal that is indicative of a low rotor RPM condition and to respond to the signal by activating the actuator to exert the actuation force.

2. The apparatus of claim 1 wherein the actuator includes a pulley arrangement that receives the flexible cable proximate to the actuator and a gear box that rotatably drives the pulley arrangement responsive to rotation of the output shaft of the motor.

3. The apparatus of claim 1 wherein the collective control includes an elongated length and wherein the actuator linkage includes a guide tube configured to support the flexible cable to translate lengthwise motion of the flexible cable from an at least generally vertical direction to a direction that is at least generally aligned to release the friction control.

4. The apparatus of claim 3 wherein the guide tube defines a passageway for slidingly receiving the flexible cable therein.

5. The apparatus of claim 4 wherein the guide tube is formed to translate the lengthwise motion.

6. The apparatus of claim 1 wherein the actuator and the flexible cable cooperate to move the collective control toward the minimum collective pitch position after the friction control reaches a disengaged position.

7. The apparatus of claim 1 wherein the actuator includes a clutch supported by the output shaft such that the clutch slips responsive to an at least partial engagement of the friction control that is maintained by the pilot.

8. The apparatus of claim 1 wherein the actuator includes a clutch supported by the output shaft such that the clutch slips relative to the output shaft of the motor to allow the pilot to overcome the actuation force.

9. A method for disengaging a friction control for use with a helicopter including a rotor system having a main rotor with an adjustable pitch that is controlled at least in part by a pilot using a collective control and the collective control pivotally supports a friction control that is engageable by the pilot to selectively increase a control force that is required as a minimum to move the collective control, said method comprising:
configuring an actuator with a motor having an output shaft for rotation to change the adjustable pitch by exerting an actuation force;
supporting a flexible cable to apply the actuation force to the friction control such that the actuation force initially disengages the friction control to decrease the control force and, thereafter, reduces the adjustable pitch toward a minimum collective pitch position;
receiving a signal that is indicative of a low rotor RPM condition; and

responding to the signal by activating the actuator to exert the actuation force.

Assignees

• Merlin Technology Inc

Inventors

• Marvin Mark
• Mercer John E
• Vetter Derek

Classifications

• B64C27/57 Primary

  automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust · CPC title

• B64C27/006

  Safety devices · CPC title

• B64C27/56

  characterised by the control initiating means, e.g. manually actuated · CPC title

• B64C27/58 Primary

  Transmitting means, e.g. interrelated with initiating means or means acting on blades (means acting on blades B64C27/72) · CPC title