US3852661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A position indicator employing magnetic circuits to monitor the position of a magnetically permeable member movable along an axis having one degree of freedom
Assignee: Westinghouse Electric Corp
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Filing: 1972-09-25
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Granted: 1974-12-03
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Expires: 1992-09-25
Abstract
Abstract A new position indicator is disclosed herein for sensing the position of a magnetized hard magnetic member. The indicator comprises a soft magnetic core having an open and a closed magnetic loop with a magnetic flux path common to both loops. The open loop has two poles associated therewith. A magnetized movable hard magnetic member is provided which is movable along an axis proximate and substantially parallel to the axis formed by the poles of the magnetic core so that movement of the magnetic member along the axis of movement thereof substantially closes the magnetic core flux path associated with the open loop at at least one point in travel thereof so as to induce a relative change in flux within the magnetic core. Detection means are provided for detecting this relative change in flux and thereby indicating the presence of said movable magnetic member substantially between the poles of the magnetic core.
Inventors
- 👤 A Szabo
- 👤 D Tarli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:10
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G21; G21C; G21C17/00; G21C17/10; G21C17/12; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
271 words
A control rod mechanism for a nuclear reactor comprising: an elongated tubular housing; an elongated control drive rod positioned for longitudinal movement within said housing, said drive rod being constructed from a magnetized magnetically hard material forming a flux source; a plurality of magnetically soft generally C-shaped cores each having a first and second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, said first magnetic loop forming a closed magnetic flux path and said second magnetic loop forming a normally open circuited magnetic flux path with two poles associated therewith, said magnetic cores positioned longitudinally along said housing; an annular ring of magnetically soft material affixed to each of the poles of said magnetic cores respectively, said annular rings closely receiving said housing within the center thereof; a saturable transformer having a primary and secondary winding forming at least a portion of each of said first magnetic loops; magnetic biasing means for magnetically biasing each of said magnet cores and providing a sufficient source of flux to saturate said transformer, said biasing means producing a flux field within said magnetic cores, respectively, which is in opposition to the flux field induced by said drive rod at the point in movement thereof where said drive rod appears across the poles of said magnetic cores, said drive rod having a sufficient source of flux to unsaturate said transformer when closing said normally open circuited magnetic core flux path; AC excitation means for exciting said primary transformer windings; and indication means for indicating a change in current across said transformer secondary windings.
Claim 2
Dependent Claim
271 words
A control rod mechanism for a nuclear reactor comprising: an elongated tubular housing; an elongated control drive rod positioned for longitudinal movement within said housing, said drive rod being constructed from a magnetized magnetically hard material forming a flux source; a plurality of magnetically soft generally C-shaped cores each having a first and second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, said first magnetic loop forming a closed magnetic flux path and said second magnetic loop forming a normally open circuited magnetic flux path with two poles associated therewith, said magnetic cores positioned longitudinally along said housing; an annular ring of magnetically soft material affixed to each of the poles of said magnetic cores respectively, said annular rings closely receiving said housing within the center thereof; a saturable transformer having a primary and secondary winding forming at least a portion of each of said first magnetic loops; magnetic biasing means for magnetically biasing each of said magnet cores and providing a sufficient source of flux to saturate said transformer, said biasing means producing a flux field within said magnetic cores, respectively, which is in opposition to the flux field induced by said drive rod at the point in movement thereof where said drive rod appears across the poles of said magnetic cores, said drive rod having a sufficient source of flux to unsaturate said transformer when closing said normally open circuited magnetic core flux path; AC excitation means for exciting said primary transformer windings; and indication means for indicating a change in current across said transformer secondary windings.
Claim 3
Dependent Claim
199 words
A magnetic position indication system comprising: an elongated movable magnetized hard magnetic member having one degree of freedom along an axis coinciding with the longitudinal dimension of said member; a plurality of soft magnetic cores each having a first and second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, said first magnetic loop forming a closed magnetic flux path and said second magnetic loop forming a normally open circuited magnetic flux path with two poles associated therewith, the poles of said plurality of magnetic cores being arranged in tandem with adjacent poles of said plurality of tandem cores interleaved along the axis of movement of said movable magnetic member and said movable magnetic member having a longitudinal dimension sufficient to subsTantially close the second magnetic loop of at least one of said soft magnetic cores at at least one point in travel thereof, so that movement of said movable member within proximity of the poles of at least one of said magnetic cores produces a relative change in flux within the corresponding magnetic cores; and means for respectively detecting a change in flux within said magnetic cores.
Claim 4
Dependent Claim
199 words
A magnetic position indication system comprising: an elongated movable magnetized hard magnetic member having one degree of freedom along an axis coinciding with the longitudinal dimension of said member; a plurality of soft magnetic cores each having a first and second magnetic loop and a magnetic flux path common to at least a portion of said first and second magnetic loops, said first magnetic loop forming a closed magnetic flux path and said second magnetic loop forming a normally open circuited magnetic flux path with two poles associated therewith, the poles of said plurality of magnetic cores being arranged in tandem with adjacent poles of said plurality of tandem cores interleaved along the axis of movement of said movable magnetic member and said movable magnetic member having a longitudinal dimension sufficient to subsTantially close the second magnetic loop of at least one of said soft magnetic cores at at least one point in travel thereof, so that movement of said movable member within proximity of the poles of at least one of said magnetic cores produces a relative change in flux within the corresponding magnetic cores; and means for respectively detecting a change in flux within said magnetic cores.
Claim 5
Dependent Claim
59 words
The magnetic position indication system of claim 2 wherein each of said plurality of soft magnetic cores comprise a generally C-shaped core having two open legs respectively forming the two poles of said second magnetic loop and a bight connected therebetween, said bight generally formed at least in part in an O-shape to provide said first closed magnetic loop.
Claim 6
Dependent Claim
58 words
The magnetic position indication system of claim 2 wherein said detection means comprises: a saturable transformer having a primary and a secondary winding, said saturable transformer forming at least a portion of said first magnetic loop; AC excitation means for exciting said primary transformer winding; and means for indicating a change in current across said transformer secondary winding.
Claim 7
Dependent Claim
100 words
The magnetic position indication system of claim 4 wherein said detection means includes magnetic biasing means for magnetically biasing said magnetic core and providing a sufficient source of flux to saturate said transformer, said biasing means producing a flux field within said magnetic core which is in opposition to the flux field produced by said movable member at the point in travel thereof where said movable member closes said normally open circuited magnetic core flux path, said movable member having a sufficient source of flux to substantially unsaturate said transformer when closing said normally open circuited magnetic core flux path.
Claim 8
Dependent Claim
125 words
The magnetic position indication system of claim 4 wherein said detection means includes magnetic biasing means for magnetically biasing said magnetic core and providing a sufficient source of flux to saturate said transformer, said biasing means producing a flux field within said magnetic core which is in opposition to the flux field induced by said movable member at the point in travel thereof where said movable member encounters the first of the two poles of said second magnetic loop in its direction of travel to close the open circuit of said second loop, said movable member having a sufficient source of flux to substantially unsaturate said transformer at the point in travel thereof adjacent the first of the two poles of said second magnetic loop.
Claim 9
Dependent Claim
55 words
The magnetic position indication system of claim 2 wherein said movable magnetic member comprises a nuclear reactor control rod and said plurality of soft magnetic cores are positioned longitudinally along the axis of movement of the control rod so as to determine the presence or absence of the control rod at the individual core locations.
Claim 10
Dependent Claim
49 words
The magnetic position indication system of claim 2 including annular rings of soft magnetic material respectively affixed to the corresponding poles of said soft magnetic cores and oriented along the axis of movement of said movable member to allow said movable member to pass through the annular openings therein.
Claim 11
Dependent Claim
44 words
The magnetic position indicator of claim 2 wherein the movable member is constructed having a dimension along its axis of movement sufficient to substantially close the second magnetic loop of substantially all of said magnetic cores at at least one point in travel thereof.
Claim 12
Dependent Claim
130 words
A magnetic position indicator comprising: a magnetic core having an open circuited magnetic flux path with two poles associated with the terminal ends of the open flux path; a movable magnetically hard magnetized member, movable along an axis proximate and substantially parallel to the axis formed by the poles of said magnetic core and sized to substantially close the open flux path of said core at at least one point in travel thereof; annular rings of sOft magnetic material respectively affixed to the corresponding poles of said magnetic core and oriented along the axis of movement of said movable member to allow said movable member to pass through the annular openings therein; and means for detecting the presence of said movable member substantially adjacent the poles of said magnetic core.
Claim 13
Dependent Claim
130 words
A magnetic position indicator comprising: a magnetic core having an open circuited magnetic flux path with two poles associated with the terminal ends of the open flux path; a movable magnetically hard magnetized member, movable along an axis proximate and substantially parallel to the axis formed by the poles of said magnetic core and sized to substantially close the open flux path of said core at at least one point in travel thereof; annular rings of sOft magnetic material respectively affixed to the corresponding poles of said magnetic core and oriented along the axis of movement of said movable member to allow said movable member to pass through the annular openings therein; and means for detecting the presence of said movable member substantially adjacent the poles of said magnetic core.
Claim 14
Dependent Claim
19 words
The magnetic position indicator of claim 10 wherein the flux path of said core includes a source of flux.
Claim 15
Dependent Claim
133 words
A magnetic position indication system comprising: a plurality of magnetic cores each having an open circuited magnetic flux path with two poles associated with the terminal ends thereof, the poles of said plurality of cores being positioned in an interleaved tandem array along a common axis; a movable magnetically permeable member having one degree of freedom along an axis parallel and substantially adjacent the common axis of the tandem array of said plurality of magnetic cores, said movable member having a dimension along its axis of movement sufficient to close the open flux path of at least one of said plurality of cores at at least one point in travel thereof; and means for respectively detecting the presence of said movable member substantially adjacent the respective poles of said plurality of magnetic cores.
Claim 16
Dependent Claim
133 words
A magnetic position indication system comprising: a plurality of magnetic cores each having an open circuited magnetic flux path with two poles associated with the terminal ends thereof, the poles of said plurality of cores being positioned in an interleaved tandem array along a common axis; a movable magnetically permeable member having one degree of freedom along an axis parallel and substantially adjacent the common axis of the tandem array of said plurality of magnetic cores, said movable member having a dimension along its axis of movement sufficient to close the open flux path of at least one of said plurality of cores at at least one point in travel thereof; and means for respectively detecting the presence of said movable member substantially adjacent the respective poles of said plurality of magnetic cores.
Claim 17
Dependent Claim
46 words
The magnetic position indication system of claim 12 wherein said movable member is constructed having a dimension along its axis of movement sufficient to substantially close the open magnetic flux path of substantially all of said magnetic cores at at least one point in travel thereof.
Claim 18
Dependent Claim
19 words
The magnetic position indication system of claim 12 wherein said movable member is constructed from magnetized hard magnetic material.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |