Cartridge for store ejection from aircraft

1. A cartridge for use in an ejector release unit, the cartridge comprising:

a gas chamber for containing gas under pressure,

an outlet of the gas chamber for releasing the gas to drive a release mechanism in the ejector release unit,

a release valve associated with the outlet and arranged to be operable to open the outlet upon activation of a firing pin of the ejector release unit, wherein the release valve is electrically operable and comprises a solenoid and electromagnet, and wherein the release valve is operable in an opening direction by gas pressure, and

a bleed air passage communicating with the release valve such that the valve is operable to open as a result of the bleed air passage receiving pressurised gas,

wherein the cartridge is reusable and is configured to be secured in a breech of the ejector release unit.

2. A cartridge as claimed in claim 1 wherein the release valve is operable by means of an electrode arranged to be aligned with the firing pin of the ejector release unit.

3. A cartridge as claimed in claim 1 wherein the release valve comprises a valve member and the bleed air passage is in fluid communication with a surface of the release valve member so that pressurised gas received in the bleed air passage acts on that surface to force the release valve member to move away from the bleed air passage.

4. A cartridge as claimed in claim 3 wherein the release valve member is contained within a release valve chamber of the cartridge adjacent the gas chamber, and the release valve member has a gas passage extending there through providing fluid communication between the gas chamber and the release valve chamber.

5. A cartridge as claimed in claim 4 wherein the release valve chamber comprises a first section receiving gas from the gas chamber, and a second section separated from the first section by a portion of the release valve member so as to be in limited fluid communication with first section.

6. A cartridge as claimed in claim 5 wherein the electromagnet is contained in an electromagnet chamber which is in fluid communication with the first section of the release valve chamber via an internal passage of the cartridge.

7. A cartridge as claimed in claim 1 wherein the cartridge comprises a vent passage extending to the outside of the cartridge allowing gas to vent out of the cartridge.

8. A cartridge as claimed in claim 7 wherein the vent passage comprises a hole adjacent a screw thread of the cartridge and a broken section of thread in the cartridge or the ejector release unit breech.

9. A cartridge as claimed in claim 7 wherein:

the release valve is electrically operable and comprises a release valve member, a solenoid, and an electromagnet, and the electromagnet is contained in an electromagnet chamber, and

the vent passage communicates with the electromagnet chamber when the release valve member is in an open position.

10. A cartridge as claimed in claim 5 wherein the cartridge comprises a vent passage extending to the outside of the cartridge and allowing gas to vent out of the cartridge, and the vent passage communicates with the second section of the release valve chamber.

11. A cartridge as claimed in claim 1 wherein the gas chamber within the cartridge is sealed by walls of the cartridge.

12. A cartridge as claimed in claim 1 wherein the release valve is closeable such that the used cartridge can be charged with compressed gas.

13. A cartridge as claimed in claim 1 wherein the gas chamber includes a one-way charging valve.

14. A cartridge as claimed in claim 1 wherein the cartridge comprises a seal arranged for preventing released gas from coming into contact with the firing pin of the ejector release unit breech.

15. An ejector release unit for an aircraft comprising the cartridge of claim 1 .

16. An ejector release unit for an aircraft comprising a pair of cartridges of claim 1 .

17. A cartridge as claimed in claim 6 , wherein the internal passage, the gas chamber, the release valve chamber, and the electromagnet chamber within the cartridge are sealed by walls of the cartridge.

18. A cartridge as claimed in claim 1 , wherein the cartridge is removable for recharging the cartridge with gas under pressure.

19. A cartridge as claimed in claim 1 , wherein the cartridge is removable for storing the cartridge.

20. A cartridge for use in an ejector release unit, the cartridge comprising:

a gas chamber for containing gas under pressure,

an outlet of the gas chamber for releasing the gas to drive a release mechanism in the ejector release unit,

a release valve associated with the outlet and arranged to be operable to open the outlet upon activation of a firing pin of the ejector release unit, wherein the release valve is electrically operable and comprises a solenoid and electromagnet, and wherein the release valve is operable in an opening direction by gas pressure, and

a bleed air passage communicating with the release valve such that the release valve is operable to open as a result of the bleed air passage receiving the pressurised gas,

wherein the cartridge is reusable and is configured to be releasably secured in a breech of the ejector release unit, and

wherein the cartridge is arranged to be rechargeable with gas under pressure after being released from the breech and before being releasably resecured in the breech.