# US 8,740,140 B2 · Multifunctional electromechanical device for landing gear

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- Number: US 8,740,140 B2
- Document ID: US8740140B2
- Status: Granted
- Kind: B2
- Application number: 13/132,158
- Filed: 2009-11-19
- Published: 2011-09-29
- Granted: 2014-06-03
- Earliest claimed: 2008-12-02
- Assignees: Messier-Bugatti-Dowty
- Applicants: Jean-Luc Alleau; Robert Kyle Schmidt
- Inventors: Jean-Luc Alleau; Robert Kyle Schmidt
- Web page: https://patentgrep.com/patent/US8740140B2

## CPC

- B64C 25/24: electric
- B64C 25/405: {Powered wheels, e.g. for taxing}
- Y02T 50/80: Energy efficient operational measures, e.g. ground operations or mission management
- B64C: AEROPLANES; HELICOPTERS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A multifunction electromechanical device for an aircraft undercarriage. The device comprises a first shaft (10) mounted to rotate on the aircraft about an axis of rotation (R) that is substantially parallel to a hinge axis (X) of the undercarriage relative to the aircraft and a telescopic second shaft (20) mounted to rotate on the undercarriage extending downwards to the proximity of the wheels carried thereby. The device also includes a transmission (19) for transmitting rotary motion from the first shaft to the second shaft and a transmission (21) for transmitting rotary motion from the second shaft to at least one wheel carried by the undercarriage. With this configuration, if the wheel is not fitted with a brake, there is a specific brake (30) for braking one of the shafts relative to the undercarriage, and a motor (11, 15) for causing the first shaft to rotate.

## Claims

### Claim 1

A method of raising an aircraft undercarriage fitted with a multifunction electromechanical device from a deployed position to a stowed position, said multifunction electromechanical device comprising at least:
a first shaft mounted to rotate on the aircraft about an axis of rotation that is substantially parallel to a hinge axis of the undercarriage relative to the aircraft;
a telescopic second shaft mounted to rotate on the undercarriage extending down therealong to the proximity of the wheels carried thereby;
transmission means for transmitting rotary motion from the first shaft to the telescopic second shaft;
transmission means for transmitting rotary motion from the telescopic second shaft to at least one wheel carried by the undercarriage;
a wheel brake fitted to the wheel; and
motor means for causing the first shaft to rotate;
the method comprising the following steps:
(1) unlocking a side-brace member of the undercarriage;
(2) preventing the second shaft of the multifunction electromechanical device from rotating relative to the undercarriage, by actuating the wheel brake; and
(3) operating the motor means to cause the first shaft to rotate relative to the structure of the aircraft.

### Claim 2

A method of lowering an aircraft undercarriage fitted with a multifunction electromechanical device from a stowed position to a deployed position, said multifunction electromechanical device comprising at least:
a first shaft mounted to rotate on the aircraft about an axis of rotation that is substantially parallel to a hinge axis of the undercarriage relative to the aircraft;
a telescopic second shaft mounted to rotate on the undercarriage extending down therealong to the proximity of the wheels carried thereby;
transmission means for transmitting rotary motion from the first shaft to the telescopic second shaft;
transmission means for transmitting rotary motion from the telescopic second shaft to at least one wheel carried by the undercarriage;
a wheel brake fitted to the wheel and
motor means for causing the first shaft to rotate;
the method comprising the steps of:
(1) releasing the undercarriage to allow it to be lowered;
(2) preventing the second shaft of the multifunction electromechanical device from rotating relative to the undercarriage, by actuating the wheel brake; and
(3) controlling the forced rotation of the motor means as induced by the lowering of the undercarriage so as to control the lowering of the undercarriage.

### Claim 3

A method of raising an aircraft undercarriage fitted with a multifunction electromechanical device from a deployed position to a stowed position, said multifunction electromechanical device comprising at least:
a first shaft mounted to rotate on the aircraft about an axis of rotation that is substantially parallel to a hinge axis of the undercarriage relative to the aircraft;
a telescopic second shaft mounted to rotate on the undercarriage extending down therealong to the proximity of the wheels carried thereby;
transmission means for transmitting rotary motion from the first shaft to the telescopic second shaft;
transmission means for transmitting rotary motion from the telescopic second shaft to at least one wheel carried by the undercarriage;
a specific brake means for braking the second shaft; and
motor means for causing the first shaft to rotate; the method comprising the following steps:
(1) unlocking a side-brace member of the undercarriage;
(2) preventing the second shaft of the multifunction electromechanical device from rotating relative to the undercarriage, by actuating the specific brake means; and
(3) operating the motor means to cause the first shaft to rotate relative to the structure of the aircraft.

### Claim 4

A method of lowering an aircraft undercarriage fitted with a multifunction electromechanical device from a stowed position to a deployed position, said multifunction electromechanical device comprising at least:
a first shaft mounted to rotate on the aircraft about an axis of rotation that is substantially parallel to a hinge axis of the undercarriage relative to the aircraft;
a telescopic second shaft mounted to rotate on the undercarriage extending down therealong to the proximity of the wheels carried thereby;
transmission means for transmitting rotary motion from the first shaft to the telescopic second shaft;
transmission means for transmitting rotary motion from the telescopic second shaft to at least one wheel carried by the undercarriage;
a specific brake means for braking the second shaft; and
motor means for causing the first shaft to rotate; the method comprising the steps of:
(1) releasing the undercarriage to allow it to be lowered;
(2) preventing the second shaft of the multifunction electromechanical device from rotating relative to the undercarriage, by actuating the specific brake means; and
(3) controlling the forced rotation of the motor means as induced by the lowering of the undercarriage so as to control the lowering of the undercarriage.