Strapdown multifunction servoactuator apparatus for aircraft

• US 4,345,195 A
• Filed: 08/08/1980
• Issued: 08/17/1982
• Est. Priority Date: 12/13/1979
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Sperry Corporation (Unisys Corporation)
• Inventors: Griffith, Carl D., Oliver, Kenneth L.
• Primary Examiner(s): Dobeck, B.
• Application Number:
  US06/176,321
• Time in Patent Office: 739 Days
• Field of Search: 318/628, 318/626, 318/584, 318/585, 318/580, 318/586, 244/223
• US Class Current: 318/628
• CPC Class Codes: B64C 13/30 using cable, chain, or rod mechanisms
• CPC Class Codes: B64C 13/345 with artificial feel
• CPC Class Codes: B64C 13/505 having duplication or stand-by provisions
• CPC Class Codes: B64C 13/507 with artificial feel
• CPC Class Codes: B64C 27/59 mechanical
• CPC Class Codes: B64C 27/68 using electrical energy, e.g. having electrical power amplification
• CPC Class Codes: G05D 1/0061 for transition from automatic pilot to manual pilot and vice versa

Abstract

Strapdown, multifunction actuator apparatus comprising one or two integral units adapted for installation in an aircraft, particularly a helicopter, and coupled between the pilot'"'"'s control stick linkage and the aircraft control surface (or surface servo boost) linkage to perform the functions of series actuation, trim actuation, artificial feel, control position sensing, and control authority limits. The apparatus includes a series actuator installed in the vehicle and connected to the vehicle control linkages in the conventional parallel actuator manner; that is, it is secured directly or strapped down to the airframe and therefore greatly simplifies control system installation and reduces problems such as those associated with control rod vibration resonances normally encountered with conventional integral-with-linkage series actuator installations.

Claims

1. A multifunction actuator apparatus for aircraft including a series actuator, the combination comprising:

housing means adapted to be mounted directly on the aircraft structure adajcent to the primary pilot controller-to-control surface actuation members and including first and second drive shafts journalled in said housing means,

first linkage means drivably supported on said first drive shaft and coupled with said pilot controller member,

second linkage means including a drive link drivably supported on said second drive shaft and further including a differential link coupled between said control surface member, and drive link and said first linkage means,

series servomotor means including means drivably connecting said servomotor to said second drive shaft for positioning said drive link, and

first and second authority limit means secured to said housing means adjacent said differential link and drive link and cooperable therewith, said first limiting means limiting the position of said pilot controller member between first predetermined maximum limits and said second limiting means limiting said drive link between second predetermined maximum limits.

2. The actuator apparatus as set forth in claim 1 wherein said housing means is a unitary housing structure.

3. The actuator apparatus as set forth in claim 1 wherein said housing means comprises at least two unitary housing structures, each adapted to be mounted directly on the aircraft structure, one including said first linkage means and the other including said second linkage means, and common interconnecting linkage means coupled between said first and second linkage means.

5. The actuator apparatus as set forth in any one of claims 1, 2, 3 or 4 wherein said authority limit means comprises:

a first pair of spaced stop surfaces cooperative with said drive link for limiting the position of said drive link between first predetermined maximum limits, and

a second pair of spaced stop surfaces cooperative with said differential link for limiting the motion of said differential link between second predetermined maximum limits, the surface contours thereof being such as to limit said differential link motion between said second maximum limits regardless of the position of said drive link.

6. The actuator apparatus as set forth in claim 5 wherein said authority limit means comprises a unitary stop structure removably secured to said housing, whereby stop structures contoured to the specific authority limit requirements of a specific aircraft may be secured to said housing.

7. The actuator apparatus as set forth in claim 5 wherein said differential link includes an open frame-like structure, wherein said drive link is substantially coplanar with said differential link and operates within said frame-like structure opening, and wherein said authority limit means includes first stop means cooperative with a part of said drive link for limiting the position thereof between said first predetermined maximum limits and second stop means substantially coplanar and cooperative with said open frame-like structure for limiting the position of said differential link between said second predetermined maximum limits.

8. The actuator apparatus as set forth in claim 7 wherein said drive link is pivotally attached to said frame-like structure and includes a part projecting from the plane thereof, which part cooperates with said first stop means to thereby limit said maximum position of said drive link.

9. The actuator apparatus as set forth in claim 7 wherein the contour of said second stop means is such as to limit said differential link motion between said second limits regardless of the position of said drive link.

10. The actuator apparatus as set forth in claims 1, 2, 3 or 4 wherein said servomotor drivable connecting means includes irreversible drive means for preventing said drive link from being positioned except by operation of said servomotor means.

11. The actuator apparatus as set forth in claim 1, 2, 3 or 4 wherein said servomotor means comprises:

dual servomotors,

differential means including means drivably connected with each of said servomotors and providing a resultant output for positioning said drive link,

each of said drivable connection means including irreversible drive means for preventing said drive link from being positioned except by said differential means.

12. The actuator apparatus as set forth in claim 1, 2 or 3 further including signal generator means coupled with said second drive shaft for providing a shaft position feedback signal for governing the operation of said servomotor means.

13. The actuator apparatus as set forth in claim 1, 2 or 3 further including:

feel spring means having a first part thereof connected with said first drive shaft and a second part connected with means providing a normally fixed reference position, whereby rotation of said first linkage means is yieldingly opposed by said feel spring thereby providing artificial surface load feel for said pilot controller.

14. The actuator apparatus as set forth in claim 13 wherein said normally fixed reference providing means comprises:

a trim servomotor means and irreversible drive means responsive thereto for preventing positioning of said second feel spring part except by operation of said trim servomotor.

15. The actuator apparatus as set forth in claim 14 wherein said normally fixed reference means further includes clutch means which when engaged couples said irreversible drive means and said second feel spring part and when disengaged uncouples said second feel spring part from said irreversible drive means and permits adjustment of said feel spring part by said first linkage means and pilot controller.

16. The actuator apparatus as set forth in claim 14 further including damper means coupled with said second feel spring part for damping any spring force on said second feel spring part upon declutching of said clutch means.

17. The actuator apparatus as set forth in claim 14 further including signal generating means coupled with said first drive shaft for providing a signal proportional to the position of said pilot controller.

18. The actuator apparatus as set forth in claim 13 wherein said feel spring includes electrical switch means coupled between said first and second feel spring parts for providing a control signal upon a predetermined relative differential position of said parts.

4. In multifunction actuator apparatus for aircraft having pilot controller-to-control surface actuation members and including first linkage means responsive to movement to said pilot'"'"'s controller the combination comprising, a series servo actuator including housing means adapted to be secured directly on the aircraft generally adjacent said actuation members, and further including a drive shaft journalled in a wall of said housing means,

second linkage means including a drive link drivably supported on said drive shaft and further including a differential link coupled between said control surface actuation member, said drive link and said first linkage means,

series servomotor means including means drivably connecting said servomotor to said drive shaft for positioning said drive link, and

first and second authority limit means secured to said housing means adjacent said differential link and drive link and cooperable therewith, said first limiting means limiting the position of said pilot controller member between first pedetermined maximum limits and said second limiting means limiting said drive link between second predetermined maximum limits.