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

Patent metadata

Field	Value
Publication number	US-9957041-B2
Application number	US-201615158521-A
Country	US
Kind code	B2
Filing date	May 18, 2016
Priority date	May 21, 2015
Publication date	May 1, 2018
Grant date	May 1, 2018

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. 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 lever as part of 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, an apparatus comprising:
an actuator including a motor having an output shaft for rotation to change the adjustable pitch by exerting an actuation force;
an actuator linkage that engages the friction lever to apply the actuation force directly to the friction control lever 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 said signal by activating the actuator arrangement to exert the actuation force.

2. The apparatus of claim 1 wherein the actuator linkage includes a flexible cable extending from the actuator to the friction control lever for applying the actuation force.

3. The apparatus of claim 2 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.

4. The apparatus of claim 2 wherein the flexible cable includes a distal end that is pivotally attached to the friction control lever.

5. The apparatus of claim 4 wherein the collective control includes an elongated length and wherein the actuator linkages 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 with the elongated length of the collective control.

6. The apparatus of claim 5 wherein the guide tube defines a passageway for slidingly receiving the flexible cable therein.

7. The apparatus of claim 6 wherein the guide tube is formed to translate the lengthwise motion.

8. The apparatus of claim 6 wherein the guide tube is supported on the collective control forward of the friction control lever.

9. The apparatus of claim 8 wherein the guide tube is sufficiently spaced apart from the friction control lever to provide for normal travel of the friction control lever between an engaged position and a disengaged position.

10. The apparatus of claim 1 wherein the actuator and the actuator linkage cooperate to initially move the friction lever from an engaged position to a disengaged position at which the friction lever stops pivotally rotating.

11. The apparatus of claim 10 wherein the actuator and the actuator linkage cooperate to move the collective control toward the minimum collective pitch position after the friction lever reaches the disengaged position.

12. 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.

13. 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 said actuation force.

14. A method 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 lever as part of 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:
responsive to an indication of a low rotor RPM of the main rotor, initially applying an actuator force to the friction control lever to move the friction control lever from an engaged position to a disengaged position; and
after the friction control lever reaches the disengaged position, continuing to apply the actuator force to the friction control lever to move the collective control, having the friction control lever pivotally supported thereon, toward a minimum collective pitch position.

15. 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 supporting a friction lever that can be engaged by the pilot to selectively increase a control force that is required as a minimum to move the collective control, an apparatus comprising:
an actuator arrangement including a motor having an output shaft for rotation to change the adjustable pitch by exerting an actuation force and a clutch supported by the output shaft and in operative communication with the collective control such that the clutch slips relative to the output shaft (i) to allow the pilot to overcome said actuation force using the collective control and (ii) responsive to an engagement of the friction lever by the pilot, but otherwise the clutch co-rotates with the motor shaft to bias 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 said signal by activating the actuator arrangement 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

• B64C27/56

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

• B64C27/006

  Safety devices · CPC title

• B64C27/59

  mechanical · 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