Apparatus for signalling position of downed aircraft

• US 3,943,445 A
• Filed: 04/08/1974
• Issued: 03/09/1976
• Est. Priority Date: 04/08/1974
• Status: Expired due to Term

• Current Assignee: Edward F. Dawson
• Original Assignee: Edward F. Dawson
• Inventors: Dawson, Edward F.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Ng, Jin F.
• Application Number:
  US05/458,848
• Time in Patent Office: 701 Days
• Field of Search: 325/111-116, 9/9, 116/124 B
• US Class Current: 455/98
• CPC Class Codes: H04B 1/034 Portable transmitters
• CPC Class Codes: H04B 2001/3894 Waterproofing of transmission device

Abstract

Apparatus to be attached to aircraft and containing signalling apparatus which is set into operation when the aircraft is downed either in water or on land. The apparatus includes a releasable element which, when the aircraft becomes submerged, floats to the surface. This element contains signalling means, and switch means which is operated to turn on the signalling means when the releasable element floats away from the aircraft. The apparatus also includes means for operating the switch means in the event of the aircraft crashing on land so as to turn on the signalling means.

Claims

1. Signalling apparatus for attachment to aircraft and operable when the aircraft crashes, comprising a buoyant container exposed to atmosphere and having therein signalling means and a self-contained electrical operating system therefor, switch means in said electrical operating system normally rendering said system inoperative, a base mountable on an aircraft at an outer surface thereof, latch means releasably securing the container to the base, operating means including a diaphragm mounted in said base and connected to said latch means, means to admit water into the base when the portion of the craft on which the base is mounted is submerged in water whereby hydrostatic pressure in the base and against said operating means causes the latter to operate said latch means to release the container and permit the latter to float to the surface, and an operator for the switch means for causing said switch means to permit the electrical system to operate when the container floats away from the base.

2. Signalling apparatus as claimed in claim 1 in which said switch means comprises a switch in the electrical operating system, and said operator comprises a finger mounted on the base and projecting into the container and normally retaining said switch open, said switch closing when moved clear of the finger.

3. Signalling apparatus as claimed in claim 1 in which said latch means comprises a latch arm movably mounted on the base and projecting into the container and having a catch thereon for engaging a keeper on the container, said operating means being operable to move the catch away from the keeper.

4. Signalling apparatus for attachment to aircraft and operable when the aircraft crashes, comprising a base mountable on an aircraft at an outer surface thereof, a buoyant container mounted on the base so as to be exposed to atmosphere and having therein signalling means and a self-contained electrical operating system therefor, a chamber in the base, a fragile tube closed at one end and in communication at another end with said chamber and mountable along a portion of the aircraft subject to damage if the aircraft crashes, said tube breaking if said portion of the aircraft is subject to extraordinary force, a fluid under pressure in the tube and the chamber, switch means in the electrical operating system, an operator for the switch means extending from the base chamber into the container and normally retained by the fluid in said chamber in a position rendering the electrical operating system inoperative, latch means releasably securing the container to the base, and operating means including a diaphragm mounted in said base and connected to said latch means, means to admit water into the base when the portion of the craft on which the base is mounted is submerged in water whereby hydrostatic pressure in the base and against said operating means causes the latter to operate said latch means to release the container and permit the latter to float to the surface, said operator causing the switch means to permit the electrical system to operate when the container separates from the base or the fragile tube is broken to release the fluid from the chamber.

5. Signalling apparatus as claimed in claim 4 in which said switch means comprises a switch in the electrical operating system and said operator comprises a finger mounted on the base and extending from the base chamber into the container and normally retaining said switch open, said switch closing when freed of the finger, and a diaphragm positioned in the base chamber and engaging the finger, the fluid in said chamber normally pressing against the diaphragm to retain said finger in its normal position.

6. Signalling apparatus as claimed in claim 4 including resilient means normally compressed between the base and the container which, when the latch means releases the container, forces said container away from the base.

7. Signalling apparatus as claimed in claim 4 in which said latch means comprises a latch arm swingably mounted in the base and projecting into the container and having a catch thereon for engaging a keeper on the container, said operating means being operable to move the catch away from the keeper.

8. Signalling apparatus as claimed in claim 7 in which said operating means comprises means connecting one face of the diaphragm to the latch arm, and pressure means on an opposite face of the diaphragm resiliently retaining the diaphragm in a position to retain the latch catch in engagement with said keeper, water pressure on said one face of the diaphragm moving said catch away from the keeper.

9. Signalling apparatus for attachment to aircraft and operable when the aircraft crashes, comprising a buoyant container having therein signalling means and a self-contained electrical operating system therefor, a base mountable on an aircraft at an outer surface thereof, latch means releasably securing the container to the base, operating means in the base for said latch means and operable by hydrostatic pressure to cause said latch means to release the container and permit the latter to float to the surface when the portion of the craft on which the base is mounted is submerged in water, said latch means comprising a latch arm movably mounted on the base and projecting into the container and having a catch thereon for engaging a keeper on the container, said operating means on being operated moving the catch away from the keeper.

10. Signalling apparatus as claimed in claim 9 in which said operating means comprises a diaphragm, means connecting one face of the diaphragm to the latch arm, and pressure means on an opposite face of the diaphragm resiliently retaining the diaphragm in a position to retain the latch catch in engagement with said keeper, water pressure on said one face of the diaphragm moving said catch away from the keeper.

11. Signalling apparatus as claimed in claim 9 including resilient means normally compressed between the base and the container which, when the latch means releases the container, forces said container away from the base.

12. Signalling apparatus as claimed in claim 9 including switch means in said electrical operating system normally rendering said system inoperative, and an operator for the switch means for causing said switch means to permit the electrical system to operate when the container separates from the base.

13. Signalling apparatus as claimed in claim 12 in which said switch means comprises a switch in the electrical operating system, and said operator comprises a finger mounted on the base and projecting into the container and normally retaining said switch open, said switch closing when moved clear of the finger.