Latch device, in particular for latching an airplane landing gear or an airplane landing gear hatch

• US 20030164421A1
• Filed: 02/06/2003
• Published: 09/04/2003
• Est. Priority Date: 03/04/2002
• Status: Active Grant

• Current Assignee: Safran Landing Systems
• Original Assignee: Messier-Bugatti (Safran SA)
• Inventors: Felemez, Eric, Fremiot, Sebastien, Liegeois, Pierre-Yves, Collet, Olivier, Perathoner, Dominique
• Granted Patent: US 6,811,118 B2
• Time in Patent Office: Days
• US Class Current: 244/102R
• CPC Class Codes: B64C 25/26 Control or locking systems therefor
• CPC Class Codes: Y10T 292/1047 Closure

Abstract

A latch device, in particular for latching an airplane landing gear or an airplane landing gear hatch, the device comprising a box containing a set of hinged elements mounted to pivot about respective parallel axes, said assembly including at least one hook and a locking lever connected to said hook by associated elastically deformable return means, said hook being capable of being unlocked by acting on said locking lever either via first actuator means in a normal mode of operation, or via a second actuator means in an emergency mode of operation when said first actuator means fails to unlock the hook. In accordance with the invention, the second actuator means associated with the emergency mode of operation is an electromechanical actuator under independent electrical control, said actuator comprising two electric motors associated in irreversible manner with a common differential gear train, having an outlet shaft controlling the pivoting of an emergency unlocking lever co-operating with the locking lever used in normal operation.

Claims

1. / A latch device, in particular for latching an airplane landing gear or an airplane landing gear hatch, the device comprising a box containing a set of hinged elements mounted to pivot about respective parallel axes, said assembly including at least one hook and a locking lever connected to said hook by associated elastically deformable return means, said hook being capable of being unlocked by acting on said locking lever either via first actuator means in a normal mode of operation, or via a second actuator means in an emergency mode of operation when said first actuator means fails to unlock the hook, wherein the second actuator means associated with the emergency mode of operation is an electromechanical actuator under independent electrical control, said actuator comprising two electric motors associated in irreversible manner with a common differential gear train, having an outlet shaft controlling the pivoting of an emergency unlocking lever co-operating with the locking lever used in normal operation.

2. / A latch device according to claim 1, wherein each motor of the electromechanical actuator is fitted downstream with a torque limiter, e.g. of the magnetic, mechanical, or friction type.

3. / A latch device according to claim 2, wherein each motor is also fitted at its outlet with irreversible clamping means, preferably of the magnetic type.

4. / A latch device according to claim 1, wherein the outlet shaft of each of the two motors engages an associated stepdown gear train, the respective outlet shaft thereof being coupled in irreversible manner to the common differential gear train, the outlet shaft of the common differential gear train causing the emergency unlocking lever to pivot.

5. / A latch device according to claim 4, wherein each stepdown gear train comprises spur gears, and the irreversible connection of its outlet shaft to the common differential gear train which is likewise made of spur gears, is provided by means of an associated wormscrew.

6. / A latch device according to claim 1, wherein the outlet shaft of each of the two motors is coupled in irreversible manner to the common differential gear train, and the outlet shaft of said common differential gear train is connected to the inlet of an epicyclic stepdown gear train, the outlet shaft of said epicyclic stepdown gear train causing the emergency unlocking lever to pivot.

7. / A latch device according to claim 6, wherein the irreversible connection of each outlet shaft with the common differential gear train which is made up of spur gears is provided by means of an associated wormscrew.

8. / A latch device according to claim 1, wherein the outlet shaft of each of the two motors is connected to a common differential gear train made of bevel gears via an associated non-return mechanism, and the outlet shaft of said common differential gear train is connected via a torque limiter to a stepdown gear train whose outlet shaft causes the emergency unlocking lever to pivot.

9. / A latch device according to claim 8, wherein the torque limiter is a friction torque limiter, and the stepdown gear train is made of spur gears.

10. / A latch device according to claim 1, wherein the electromechanical actuator with its two electric motors and its common differential gear train is fixed to the box in removable manner, and is easily accessible, thereby enabling it to be directly replaced by another actuator without needing to dismantle said box.

11. / A latch device according to claim 1, wherein the first actuator means associated with the normal mode of operation is likewise an electromechanical actuator under independent electric control, said actuator being of low power and being constituted by an electromagnet, or a motor and stepdown gear box unit, or a torque motor of small size.