IP Library Granted Patent US 12,389,554
Granted Patent B2
US 12,389,554 · App. 17/467,447 · Granted Aug 12, 2025

Crash protected memory unit

Inventors: Nikolaus Stehle (Meersburg, DE); Markus Metzler (Ravensburg, DE)
Assignee: HENSOLDT SENSORS GMBH
H05K5/021B64D45/00G06F1/206G06F1/3206
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Quick Facts
Patent No.
US 12,389,554
App. No.
17/467,447
Granted
Aug 12, 2025
Kind
B2
Abstract

A crash-protected memory unit ( 100 ) for a flight recorder comprises: an electronic memory ( 110 ), configured to store data; an active casing ( 120 ), configured to encase the electronic memory ( 110 ), and comprising a heat absorption material ( 125 ), adapted to absorb heat by undergoing an endothermic chemical process, thereby providing an active thermal insulation of the electronic memory ( 110 ); and a passive casing ( 130 ), configured to encase the active casing ( 120 ), and comprising a heat resistant material ( 135 ) for providing a passive thermal insulation for the electronic memory ( 110 ).

Claims (48)

1. A crash-protected memory unit for a flight recorder, the crash-protected memory unit comprising:

an electronic memory, configured to store data;

an active casing, configured to encase the electronic memory, and comprising a heat absorption material, adapted to absorb heat by undergoing an endothermic chemical process, thereby providing an active thermal insulation of the electronic memory;

a passive casing, configured to encase the active casing, and comprising a heat resistant material for providing a passive thermal insulation for the electronic memory,

wherein the heat absorption material comprises an inorganic hydrate, adapted to undergo, as the endothermic chemical process, a dehydration,

wherein the passive casing and/or the active casing comprise a plurality of openings, adapted to admit a passage of gaseous water, and

wherein the heat absorption material comprises one or more of the following inorganic hydrates:

copper(I) sulfate pentahydrate,

copper(II) sulfate tetrahydrate,

copper(II) sulfate nonahydrate, and/or

copper(II) sulfate pentahydrate;

wherein dehydration of the one or more inorganic hydrates provides a cooling effect through an absorption of heat energy when undergoing the endothermic chemical process; and

wherein the passive casing comprises a spherical surface enclosing the active casing and the electronic memory.

2. The crash-protected memory unit of claim 1 , further comprising one or more of the following:

a power supply, configured to provide power to the electronic memory,

a controller unit, configured to control the electronic memory.

3. The crash-protected memory unit of claim 1 , wherein the heat absorption material is adapted to undergo the endothermic chemical process in more than one stage, each stage corresponding to a respective ambient temperature.

4. The crash-protected memory unit of claim 1 , wherein the active casing ( 120 ) comprises the inorganic hydrate within a container, and the container comprises at least some openings of the plurality of openings.

5. The crash-protected memory unit of claim 1 , wherein at least one opening of the plurality of openings is filled with a sealing material, and wherein a melting or sublimation point of the sealing material is related to a dehydration temperature of the inorganic hydrate.

6. The crash-protected memory unit of claim 1 , wherein the heat resistant material comprises a microporous material containing one or more of the following:

a ceramic material,

silicon,

aluminum,

asbestos,

silicic acid.

7. The crash-protected memory unit of claim 1 , wherein a thickness of the active casing and/or of the passive casing is adapted to keep the stored data in the electronic memory intact if the crash-protected memory unit is exposed to a predefined temperature, in particular 1000° C., for a predefined period of time, in particular 20 minutes or one hour.

8. A flight recorder, comprising the crash-protected memory unit of claim 1 .

9. An aircraft, comprising the flight recorder of claim 8 .

10. A method for producing a crash protected memory, comprising the steps:

providing a casing in form of two half-shells, a heat absorption material, and an electronic memory;

pressing the heat absorption material into the half-shells;

forming one or more indentations in the heat absorption material;

inserting the electronic memory in the one or more indentations;

combining the half-shells holding the heat absorption material and the electronic memory in order to produce the crash-protected memory unit,

wherein the heat absorption material comprises an inorganic hydrate, adapted to undergo, as the endothermic chemical process, a dehydration,

wherein the passive casing and/or the active casing comprise a plurality of openings, adapted to admit a passage of gaseous water, and

wherein the heat absorption material comprises one or more of the following inorganic hydrates:

copper(I) sulfate pentahydrate,

copper(II) sulfate tetrahydrate,

copper(II) sulfate nonahydrate, and/or

copper(II) sulfate pentahydrate;

wherein dehydration of the one or more inorganic hydrates provides a cooling effect through an absorption of heat energy when undergoing the endothermic chemical process; and

wherein the passive casing comprises a spherical surface enclosing the active casing and the electronic memory.

11. The method of claim 10 , wherein combining the half-shells comprises one or more of the following:

a welding,

a sealing of openings,

an establishing of an interlocking engagement using a thread, a bayonet joint, a hook, or another mechanical connection.

12. The crash-protected memory unit of claim 1 , wherein the one or more inorganic hydrates are copper (II) sulfate hydrates, CuSO 4 ·nH 2 O, wherein n is a number of water molecules of hydration, and n can range from 1 to 9.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jun 30, 2025
From: STEHLE, NIKOLAUS; METZLER, MARKUS
To: HENSOLDT SENSORS GMBH
Reel/Frame 071569/0599 →
Priority Claims (1)
EP 20195125 · Sep 8, 2020 · regional
Continuity (1)
Related Publication 20220073212A1 · Mar 10, 2022
References Cited (7)
US 4694119A · Groenewegen · 1987 [cited by examiner]
US 5370814A · Salyer · 1994 [cited by applicant]
US 5750925A · Purdom · 1998 [cited by examiner]
CN 102241820B · 2013 [cited by examiner]
EP 2688377A2 · 2014 [cited by applicant]
RU 2651428C2 · 2018 [cited by applicant]
English Machine Translation of CN-102241820-B (Year: 2011). [cited by examiner]