Method and apparatus for clearing a blockage in a pitot or static pressure line of a duct of a pressure sensor

Patent metadata

Field	Value
Publication number	US-9239336-B2
Application number	US-201214119833-A
Country	US
Kind code	B2
Filing date	May 15, 2012
Priority date	May 23, 2011
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

Apparatus and method for providing the apparatus, the apparatus including: a duct; and a non-return valve; wherein the duct has a first portion and a second portion; the first portion has a first end and a second end; the first end is open to a fluid (e.g. air); the second end is connected to the second portion such that fluid is permitted to flow between the first portion and the second portion; the non-return valve is positioned at or proximate to the second end; and the non-return valve is arranged such that, upon application of a suction force to the first portion at the first end, fluid flows into the first portion via the non-return valve from outside the duct, and through the first portion from the second end to the first end.

First claim

The invention claimed is:

1. A method for clearing a blockage in a pitot pressure line or a static pressure line of a duct of a pressure sensor, the duct comprising a first portion, the pitot or static pressure line, and a second portion,
the first portion having an open end and a further end;
the open end being open to a fluid;
the further end being connected to the second portion such that the fluid is permitted to flow between the first portion and the second portion during pressure measurement;
the second portion having a first opening and a second opening, the further end being connected to the first opening, the second opening being connectable to a pressure transducer;
the method comprising the steps of:
arranging a non-return valve being connected to the first opening of the second portion such that the non-return valve is positioned at or proximate to the further end of the first portion; and
upon application of a suction force to the first portion at the open end, fluid flows into the first portion via the non-return valve from outside the duct, and through the first portion from the further end to the open end;
applying a suction force to the first portion at the open end so as to remove the blockage from the first portion; and
upon application of a suction force to the first portion at the open end, the non-return valve acts to reduce effects of the suction force on the pressure transducer.

2. The method according to claim 1 , the method further comprising connecting a filter to an inlet of the non-return valve such that fluid allowed to flow into the duct by the non-return valve is filtered by the filter.

3. The method according to claim 1 , wherein the first portion comprises a length of flexible tubing.

4. The method according to claim 1 , wherein at least part of the first portion has an internal diameter of less than 5 mm.

5. The method according to claim 1 , wherein the fluid is air.

6. The method according to claim 1 , wherein the pressure transducer is onboard an aircraft.

7. Apparatus for clearing a blockage in a pitot pressure line or static pressure line of a duct of a pressure sensor, the apparatus comprising:
the duct having a first portion, the pitot and static pressure line and a second portion;
the first portion having an open end and a further end, the open end being open to a fluid, the further end being connected to the second portion such that the fluid is permitted to flow between the first portion and the second portion during pressure measurement;
the second portion having a first opening and a second opening, the further end of the first portion being connected to the first opening, the second opening being connectable to a pressure transducer;
a non-return valve connected to the first opening of the second portion such that the non-return valve is positioned at or proximate to the further end of the first portion, and arranged such that, upon application of a suction force to the first portion at the open end, fluid flows into the first portion via the non-return valve from outside the duct, and through the first portion from the further end to the open end;
means for applying a suction force to the first portion at the open end.

8. An aircraft comprising the apparatus of claim 7 .

9. The aircraft according to claim 8 , wherein the aircraft is an unmanned aircraft.

10. The aircraft according to claim 8 , wherein the apparatus is housed in, mounted on, or integrated in a wing of the aircraft such that the first end is substantially flush with a surface of the wing.

11. The aircraft according to claim 8 , wherein a crack pressure of the non-return valve is greater than a maximum pressure differential across the non-return valve specified for the non-return valve whilst the aircraft is in-flight.

Assignees

• Ellison William Frank
• Ceney Clive Edwin
• Bae Systems Plc

Inventors

• Ellison William Frank
• Ceney Clive Edwin

Classifications

• G01P13/025

  indicating air data, i.e. flight variables of an aircraft, e.g. angle of attack, side slip, shear, yaw · CPC title

• G01P5/14

  by measuring differences of pressure in the fluid · CPC title

• B08B5/04

  Cleaning by suction, with or without auxiliary action · CPC title

• B23P11/00

  Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for  (connecting sheet metal or metal tubes, rods or profiles B21D39/00; riveting B21J; soldering, unsoldering, welding B23K; hand tools for connecting wire or strip B25B25/00; connecting metal parts by adhesives F16B11/00) · CPC title

• G01P3/62 Primary

  Devices characterised by the determination or the variation of atmospheric pressure with height to measure the vertical components of speed (measuring pressure in general G01L) · CPC title