No-Back Device Having Malfunction Detection

• US 20080000730A1
• Filed: 09/08/2005
• Published: 01/03/2008
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Goodrich Actuation System SAS (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Actuation System SAS (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Medina, Raphael, Port-Robach, Isabelle
• Granted Patent: US 8,146,858 B2
• Time in Patent Office: Days
• US Class Current: 188/71.2
• CPC Class Codes: B64C 13/28 mechanical
• CPC Class Codes: F16D 41/12 with hinged pawl co-operating with teeth, cogs, or the like F16D41/02, F16D41/24 take precedence
• CPC Class Codes: F16H 2035/005 Gearings or mechanisms preventing back-driving braking or locking of screw actuators F16H25/2454
• CPC Class Codes: F16H 25/2454 Brakes; Rotational locks
• CPC Class Codes: Y10T 74/2133 Pawls and ratchets

Abstract

The invention relates to a no-back device for a mobile element actuating device including a screw shaft having first and second braking means each comprising a ratchet wheel. These ratchet wheels are mounted opposite one another so that the first braking means are adapted to resist an unwanted movement of the screw shaft in a first direction, and the second braking means are adapted to resist an unwanted movement of the screw shaft in an opposite direction. The no-back device also includes means for detecting the state of the rotation of the ratchet wheels and indicating means for furnishing, according to the state of the rotation of the wheels, an indication concerning the operating state of the no-back device.

Claims

1-9. -9. (canceled)

10. A no-back device for an actuating device for a mobile actuating element with a screw type actuating shaft, the no-back device comprising:

first (3, 5, 7, 9, 11, 15, 19) and second (4, 6, 8, 10, 12, 16, 18) brakes, each having a ratchet wheel (5, 6), the ratchet wheels mounted in opposition to each other with the first brake designed to resist an unwanted movement of the shaft in a first direction, and the second brake designed to resist an unwanted movement of the shaft in an opposite direction,

means (25, 26) for detecting the state of rotation of each of the wheels (5, 6), and

indicating means to supply an indication relating to the operational state of the no-back device, the indicating means including means for comparing the state of rotation of each of the wheels, and alert means for supplying an indication of failure when the compared rotation states are identical.

11. A device according to claim 10, wherein the detection means determine, for each wheel, whether said wheel is stationary or driven in rotation.

12. A device according to claim 11, wherein the ratchet wheels comprise a ferromagnetic material, and the detection means comprise a pair of inductive sensors (25, 26), with each sensor located on a periphery of a ratchet wheel (5, 6) with a magnetic field induced in the sensor sensitive to variation in a magnetic gap between the sensor and the wheel.

13. A device according to claim 12, wherein each sensor is located so that the magnetic gap varies dependent on the sensor being located opposite to a top of a tooth or opposite to a base of a tooth of the sprocket wheel.

14. A device according to claim 12, wherein the detection means also comprise a processor associated with the sensors, the processor designed to determine, for each wheel as a function of variations of the induced magnetic field, whether the wheel is stationary or driven in rotation.

15. A device according to claim 10, wherein the ratchet wheels comprise a ferromagnetic material, and the detection means comprise a pair of inductive sensors (25, 26), with each sensor located on a periphery of a ratchet wheel (5, 6) with a magnetic field induced in the sensor sensitive to variation in a magnetic gap between the sensor and the wheel.

16. A device according to claim 15, wherein each sensor is located so that the magnetic gap varies dependent on the sensor being located opposite to a top of a tooth or opposite to a base of a tooth of the sprocket wheel.

17. A device according to claim 15, wherein the detection means also comprise a processor associated with the sensors, the processor designed to determine, for each wheel as a function of variations of the induced magnetic field, whether the wheel is stationary or driven in rotation.

18. A device according to claim 10, wherein the indicating means also supply information that can be used to characterize a failure of the no-back device.

19. An actuating device for a mobile element, comprising a no-back device according to claim 10.

20. The actuating device of claim 19 effective to control flight of an aircraft.

21. A method for determining an operational state of a no-back device for an actuating device for a mobile element in an aircraft, which has a screw type actuating shaft, where the no-back device includes first (3, 5, 7, 9, 11, 1519) and second (4, 6, 8, 10, 12, 16, 18) brakes, each of which has a ratchet wheel (5, 6), the ratchet wheels mounted in opposition to each other with the first brake designed to resist an unwanted movement of the shaft in a first direction, and the second brake designed to resist an unwanted movement of the shaft in an opposite direction, the method comprising:

detecting a rotation state for the ratchet wheels, and

indicating an operational state of the no-back device as a function of the said detecting,

wherein said indicating step comprises comparing the rotational state of each of the wheels and supplying an indication of failure in the case where the compared states are identical.