Patent US4996479A successfully refreshed from Google Patents.
US4996479A
Expired / Lapsed
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Magnetometer device with a Dewar vessel for measuring weak magnetic fields
Assignee: Siemens AG
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Filing: 1989-09-15
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Granted: 1991-02-26
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Expires: 2009-09-15
Abstract
Abstract A magnetometer device for measuring the magnetic fields caused by field sources includes a Dewar vessel that has an interior with access through a neck. The interior contains several superconducting gradiometers as well as corresponding SQUIDs. The Dewar vessel is arranged underneath or laterally to the field source. An insertion vessel for a liquid refrigerant which is thermally coupled to the SQUIDs and is located in the interior. The gaseous refrigerant taken from the insertion vessel is supplied to the gradiometers through hose lines. The refrigerant escaping into the interior is discharged to the outside via the neck. A throttling device is inserted into the neck to prevent warmer gaseous refrigerant from entering the interior.
Inventors
- 👤 Eckhardt Hoenig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:56
CPC Classifications
A; A61; A61B; A61B5/00; A61B5/24; A61B5/242; F; F17; F17C; F17C3/00; F17C3/02; F17C3/08; F17C3/085; G; G01; G01R; G01R33/00; G01R33/02; G01R33/035; G01R33/0354; G01R33/0358; F17C2270/00; F17C2270/05; F17C2270/0527; F17C2270/0536; Y; Y10; Y10S; Y10S220/00; Y10S220/901
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
161 words
A magnetometer device for measuring weak magnetic fields, of at least one field source comprising: a Dewar vessel arranged below or laterally to the at least one field source and having an interior region and a neck, said interior region being accessed via said neck; an insertion vessel disposed in the interior region of the Dewar vessel in which liquid refrigerant can be retained; a plurality of superconducting gradiometers and associated SQUIDs arranged in the interior region of the Dewar vessel, the SQUIDs being positioned in or at the insertion vessel; a pipeline terminating in said insertion vessel and extending through the neck feeding liquid refrigerant through the neck from outside the Dewar vessel; at least one hose line extending from the insertion vessel to the superconducting gradiometers feeding gaseous refrigerant to said gradiometers; and a throttling device positioned in the neck for inhibiting warmer gaseous refrigerant from flowing back into the interior region, said pipeline extending through said throttling device.
Claim 2
Dependent Claim
161 words
A magnetometer device for measuring weak magnetic fields, of at least one field source comprising: a Dewar vessel arranged below or laterally to the at least one field source and having an interior region and a neck, said interior region being accessed via said neck; an insertion vessel disposed in the interior region of the Dewar vessel in which liquid refrigerant can be retained; a plurality of superconducting gradiometers and associated SQUIDs arranged in the interior region of the Dewar vessel, the SQUIDs being positioned in or at the insertion vessel; a pipeline terminating in said insertion vessel and extending through the neck feeding liquid refrigerant through the neck from outside the Dewar vessel; at least one hose line extending from the insertion vessel to the superconducting gradiometers feeding gaseous refrigerant to said gradiometers; and a throttling device positioned in the neck for inhibiting warmer gaseous refrigerant from flowing back into the interior region, said pipeline extending through said throttling device.
Claim 3
Dependent Claim
52 words
An apparatus as claimed in claim 1, wherein the throttling device comprises a stack of several washer-like throttling elements inserted in the neck to increase the flow resistance for the gaseous refrigerant and which, together with the inner wall of the neck, form at least one narrow gap for the gaseous refrigerant.
Claim 4
Dependent Claim
43 words
An apparatus as claimed in claim 2, wherein the throttling elements are elastic in at least a portion of their outer rim, the gap being formed or enlarged by bending of the outer rim in response to pressure caused by the gaseous refrigerant.
Claim 5
Dependent Claim
39 words
An apparatus as claimed in claim 2, wherein each throttling element includes: a central clamping holder that surrounds the pipeline for the refrigerant in the area of the neck; a washer-shaped plastic plate fastened to the central clamping holder.
Claim 6
Dependent Claim
28 words
An apparatus as claimed in claim 4, wherein the plastic plate has an outside diameter that is substantially larger than the outside diameter of the central clamping holder.
Claim 7
Dependent Claim
17 words
An apparatus as claimed in claim 4, wherein the plastic plate is made from a polyester foil.
Claim 8
Dependent Claim
39 words
An apparatus as claimed in claim 3, wherein each throttling element includes: a central clamping holder that surrounds the pipeline for the refrigerant in the area of the neck; a washer-shaped plastic plate fastened to the central clamping holder.
Claim 9
Dependent Claim
28 words
An apparatus as claimed in claim 6, wherein the plastic plate has an outside diameter that is substantially larger than the outside diameter of the central clamping holder.
Claim 10
Dependent Claim
39 words
An apparatus as claimed in claim 1, further comprising a lid on the insertion vessel, the hose line by attaching to an opening in the lid whereby the lid will function as a gas distributor for the hose line.
Claim 11
Dependent Claim
31 words
An apparatus as claimed in claim 1, further comprising electrical connecting leads between the SQUIDs and the gradiometers that are thermally coupled to the gaseous refrigerant flowing in the hose lines.
Claim 12
Dependent Claim
24 words
An apparatus as claimed in claim 10, wherein the connecting leads comprise at least part of the hose lines for carrying the gaseous refrigerant.
Claim 13
Dependent Claim
20 words
An apparatus as claimed in claim 1, further comprising glass balls that fill the interior region of the Dewar vessel.
Claim 14
Dependent Claim
33 words
An apparatus as claimed in claim 1, wherein the Dewar vessel is integrated in an examination table for a patient so that the field source above or lateral relative to the Dewar vessel.
Claim 15
Dependent Claim
19 words
An apparatus as claimed in claim 1, wherein the neck of the Dewar vessel lies below the interior region.
Claim 16
Dependent Claim
23 words
An apparatus as claimed in claim 13, wherein the examination table includes means for venting of the interior region of the Dewar vessel.
Claim 17
Dependent Claim
16 words
An apparatus as claimed in claim 15, wherein the venting means comprises passive underpressure venting means.
Claim 18
Dependent Claim
16 words
An apparatus as claimed in claim 15, wherein the venting means comprises active underpressure venting means.
Claim 19
Dependent Claim
28 words
An apparatus as claimed in claim 1, wherein the Dewar vessel has an axis that forms a predetermined angle relative to the insertion vessel in the interior region.
Claim 20
Dependent Claim
14 words
An apparatus as claimed in claim 1, wherein the Dewar vessel has rotational symmetry.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-25 | 1994-08-27 | 1995-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-25 | 1998-08-27 | 1999-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-25 | 2002-08-27 | 2003-02-26 | $7700.00 | Window Closed / Lapsed |