US5187939A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rapid cooldown dewar
Assignee: OL Security LLC
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Filing: 1991-06-03
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Granted: 1993-02-23
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Expires: 2011-06-03
Abstract
Abstract A dewar (20) useful in rapidly cooling a sensor (28) supported thereon includes a bore tube assembly having a cylindrical dewar bore tube (22) with an end cap (24) at one end to close the bore tube (22). The bore tube assembly is cooled by directing a stream of coolant at the interior of the end cap (24). The sensor (28) is mounted directly to the exterior surface of the end cap (24). A cold shield (34) partially encloses the sensor (28). A cold shield support bracket (38) mounts the cold shield (34) to the cylindrical side walls of the dewar bore tube (22) at a mounting location (36) axially displaced from the end cap (24) and therefore less effectively cooled than the end cap (24), so that heat is extracted from the support bracket (38) and the cold shield (34) less rapidly than from the sensor (28). From an uncooled starting condition, the sensor (28) is cooled to its operating temperature, and the cold shield (34) is cooled to its operating temperature, in about the same time.
Inventors
- 👤 Matthew M. Skertic
- 👤 Joseph L. Hlava
- 👤 Arthur A. Eneim
- 👤 Nevil Q. Maassen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:14
CPC Classifications
F; F25; F25D; F25D19/00; F25D19/006; F17; F17C; F17C3/00; F17C3/02; F17C3/08; F17C3/085; G; G01; G01J; G01J5/00; G01J5/02; G01J5/06; G01J5/061; F17C2201/00; F17C2201/01; F17C2201/0104; F17C2201/0119; F17C2203/00; F17C2203/06; F17C2203/0634; F17C2203/0636; F17C2227/00; F17C2227/03; F17C2227/0337; F17C2250/00; F17C2250/04; F17C2250/0404; F17C2250/0439; F25D2400/00; F25D2400/28
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
99 words
A dewar assembly, comprising: a dewar bore tube; a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface; a sensor mounted to the external surface of the dewar bore tube end cap; a cold shield partially surrounding the sensor; and a cold shield support bracket that supports the cold shield, said support bracket engaging said bore tube at a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap.
Claim 2
Dependent Claim
99 words
A dewar assembly, comprising: a dewar bore tube; a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface; a sensor mounted to the external surface of the dewar bore tube end cap; a cold shield partially surrounding the sensor; and a cold shield support bracket that supports the cold shield, said support bracket engaging said bore tube at a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap.
Claim 3
Dependent Claim
16 words
The dewar assembly of claim 1, wherein the dewar bore tube and cold shield are cylindrical.
Claim 4
Dependent Claim
32 words
The dewar assembly of claim 1, wherein the cold shield is made of a material selected from the group of high thermal diffusivity metals consisting of copper and aluminum and their alloys.
Claim 5
Dependent Claim
38 words
The dewar assembly of claim 1, wherein the cold shield support bracket is made at least in part of a material selected from the group of high thermal diffusivity metals consisting of copper and aluminum and their alloys.
Claim 6
Dependent Claim
188 words
A dewar assembly, comprising: a hollow cylindrical dewar bore tube; a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface; a sensor mounted to the external surface of the dewar bore tube end cap; a cylindrical cold shield partially surrounding the sensor, the cold shield having a cylindrical diameter greater than that of the dewar bore tube and being made from a material selected from the group of high thermal diffusivity metals consisting of copper and aluminum and their alloys; and a cold shield support bracket that supports the cold shield from a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap, the cold shield support bracket including a ceramic interconnect card having electrical surface traces and upon which the cold shield is supported, and a metallic cold shield support bracket attached to a cylindrical surface of the dewar bore tube at a first end and upon which the interconnect card is supported at a second end.
Claim 7
Dependent Claim
188 words
A dewar assembly, comprising: a hollow cylindrical dewar bore tube; a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface; a sensor mounted to the external surface of the dewar bore tube end cap; a cylindrical cold shield partially surrounding the sensor, the cold shield having a cylindrical diameter greater than that of the dewar bore tube and being made from a material selected from the group of high thermal diffusivity metals consisting of copper and aluminum and their alloys; and a cold shield support bracket that supports the cold shield from a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap, the cold shield support bracket including a ceramic interconnect card having electrical surface traces and upon which the cold shield is supported, and a metallic cold shield support bracket attached to a cylindrical surface of the dewar bore tube at a first end and upon which the interconnect card is supported at a second end.
Claim 8
Dependent Claim
21 words
The dewar assembly of claim 5, wherein the dewar bore tube is made of an iron-nickel alloy with low thermal conductivity.
Claim 9
Dependent Claim
20 words
The dewar assembly of claim 5, further including an outer housing around the dewar bore tube and the cold shield.
Claim 10
Dependent Claim
132 words
A missile, comprising: a body; means for sensing the field of view forward of the missile, the means for sensing including a dewar assembly having a dewar bore tube, a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface, a sensor mounted to the external surface of the dewar bore tube end cap, a cold shield partially surrounding the sensor, and a cold shield support bracket that supports the cold shield, said support bracket engaging said bore tube at a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap; and a cooling unit that cools the sensor and the cold shield.
Claim 11
Dependent Claim
132 words
A missile, comprising: a body; means for sensing the field of view forward of the missile, the means for sensing including a dewar assembly having a dewar bore tube, a dewar bore tube end cap that closes one end of the dewar bore tube, the dewar bore tube end cap having an outwardly facing external surface, a sensor mounted to the external surface of the dewar bore tube end cap, a cold shield partially surrounding the sensor, and a cold shield support bracket that supports the cold shield, said support bracket engaging said bore tube at a location on the dewar bore tube displaced longitudinally along the length of the dewar bore tube from the dewar bore tube end cap; and a cooling unit that cools the sensor and the cold shield.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-02-23 | 1996-08-24 | 1997-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-23 | 2000-08-24 | 2001-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-23 | 2004-08-24 | 2005-02-23 | $7700.00 | Window Closed / Lapsed |