Thermal trigger with an integrated out-of-line lockout device for a thermally-initiated ventilation system or other system

Patent metadata

Field	Value
Publication number	US-9696125-B2
Application number	US-201514802683-A
Country	US
Kind code	B2
Filing date	Jul 17, 2015
Priority date	Jul 17, 2015
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A device includes a thermal trigger having a firing pin, where the thermal trigger is configured to move the firing pin in response to an elevated temperature. The device also includes an out-of-line lockout device configured to disarm the thermal trigger in response to acceleration of the lockout device. The lockout device is configured to move a first lockout ball into a notch of the firing pin to disarm the thermal trigger. The lockout device could include an inertial mass configured to move the first lockout ball into the notch of the firing pin and a first spring configured to bias the inertial mass in an initial position. The lockout device could also include a second lockout ball configured to move into a position that prevents the inertial mass from returning to the initial position or a dampener configured to slow movement of the inertial mass.

First claim

What is claimed is:

1. A device comprising:
a thermal trigger comprising a firing pin, the thermal trigger configured to move the firing pin in response to an elevated temperature; and
an out-of-line lockout device configured to disarm the thermal trigger in response to acceleration of the lockout device, the lockout device configured to move a first lockout ball into a notch of the firing pin to disarm the thermal trigger.

2. The device of claim 1 , wherein the lockout device comprises:
an inertial mass configured to move the first lockout ball into the notch of the firing pin; and
a first spring configured to bias the inertial mass in an initial position.

3. The device of claim 2 , wherein the lockout device further comprises:
a second lockout ball configured, in response to movement of the inertial mass away from the initial position, to move into a position that prevents the inertial mass from returning to the initial position.

4. The device of claim 3 , wherein the lockout device further comprises:
a second spring and a plunger configured to push the second lockout ball into the position that prevents the inertial mass from returning to the initial position.

5. The device of claim 2 , wherein the lockout device further comprises:
a dampener configured to slow movement of the inertial mass.

6. The device of claim 5 , wherein the dampener comprises an orifice plug dividing an internal cavity of the inertial mass, the orifice plug defining a narrow passageway through the orifice plug.

7. The device of claim 1 , wherein the thermal trigger further comprises:
a shape memory material member having a first end and a second end, the first end connected to the firing pin, the second end connected to a fixed location; and
a second spring configured to move the firing pin in response to fracturing of the shape memory material member.

8. The device of claim 7 , wherein:
the shape memory material member comprises an elongated structure;
the elongated structure is configured to decrease in length when exposed to the elevated temperature; and
the elongated structure comprises at least one notch that defines a reduced-width portion of the elongated structure.

9. The device of claim 1 , wherein the device is insensitive to orientation about a longitudinal axis of the device.

10. A system comprising:
a motor casing; and
a device comprising:
a thermal trigger comprising a firing pin, the thermal trigger configured to move the firing pin in response to an elevated temperature and trigger an explosive device that damages the motor casing; and
an out-of-line lockout device configured to disarm the thermal trigger in response to acceleration of the lockout device, the lockout device configured to move a first lockout ball into a notch of the firing pin to disarm the thermal trigger.

11. The system of claim 10 , wherein the lockout device comprises:
an inertial mass configured to move the first lockout ball into the notch of the firing pin; and
a first spring configured to bias the inertial mass in an initial position.

12. The system of claim 11 , wherein the lockout device further comprises:
a second lockout ball configured, in response to movement of the inertial mass away from the initial position, to move into a position that prevents the inertial mass from returning to the initial position.

13. The system of claim 12 , wherein the lockout device further comprises:
a second spring and a plunger configured to push the second lockout ball into the position that prevents the inertial mass from returning to the initial position.

14. The system of claim 11 , wherein the lockout device further comprises:
a dampener configured to slow movement of the inertial mass, the dampener comprising an orifice plug dividing an internal cavity of the inertial mass, the orifice plug defining a narrow passageway through the orifice plug.

15. The system of claim 10 , wherein the thermal trigger further comprises:
a shape memory material member having a first end and a second end, the first end connected to the firing pin, the second end connected to a fixed location; and
a second spring configured to move the firing pin in response to fracturing of the shape memory material member.

16. The system of claim 15 , wherein:
the shape memory material member comprises an elongated structure;
the elongated structure is configured to decrease in length when exposed to the elevated temperature; and
the elongated structure comprises at least one notch that defines a reduced-width portion of the elongated structure.

17. The system of claim 10 , further comprising:
a flight vehicle comprising the motor casing; and
a cutting charge comprising the explosive device.

18. A method comprising:
disarming a thermal trigger that comprises a firing pin, the thermal trigger configured to move the firing pin in response to an elevated temperature;
wherein disarming the thermal trigger comprises using an out-of-line lockout device to disarm the thermal trigger in response to acceleration of the lockout device, the lockout device configured to move a first lockout ball into a notch of the firing pin to disarm the thermal trigger.

19. The method of claim 18 , wherein using the out-of-line lockout device to disarm the thermal trigger comprises:
moving an inertial mass away from an initial position in response to the acceleration of the lockout device;
pushing the first lockout ball into the notch of the firing pin using the inertial mass; and
in response to movement of the inertial mass away from the initial position, moving a second lockout ball into a position that prevents the inertial mass from returning to the initial position.

20. The method of claim 19 , further comprising:
dampening acceleration forces applied to the inertial mass to prevent unintended disarming of the thermal trigger by the out-of-line lockout device.

Assignees

• Raytheon Co

Inventors

• Merems Paul A

Classifications

• F02K9/38

  Safety devices, e.g. to prevent accidental ignition · CPC title

• F42C19/08 Primary

  Primers (initiators for blasting cartridges F42B3/10; ignition means for rocket engine plants F02K9/95); Detonators · CPC title

• F42C15/44

  Arrangements for disarming, or for rendering harmless, fuzes after arming, e.g. after launch · CPC title

• F42B39/14 Primary

  Explosion or fire protection arrangements on packages or ammunition (F42B39/20 {and F42B39/24} take precedence; {wall or panel structure of fireproof safes or storage containers E05G1/024}) · CPC title

• F42B39/20

  Packages or ammunition having valves for pressure-equalising; Packages or ammunition having plugs for pressure release, e.g. meltable {; Blow-out panels; Venting arrangements (ventilating arrangements on packages formed from foldable or erectable blanks B65D5/4295; packages with pressure-relief valves incorporated in a container wall B65D77/225)} · CPC title