US3665511A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic detection apparatus
Assignee: Superior Essex Inc
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Filing: 1970-03-02
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Granted: 1972-05-23
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Expires: 1990-03-02
Abstract
Abstract Detection apparatus for rapidly and accurately locating a hidden ferromagnetic object (such as a magnet buried in the earth to mark the location of underground equipment). The overlapping reeds in an evacuated reed switch capsule are set into motion by a fluctuating magnetic field. The strength of this fluctuating field is adjusted such that the two reeds nearly come into contact as they are deflected toward one another by the applied field. The presence of the additional, steady field created by a nearby ferrous object causes the reeds to actually make contact, thereby energizing a signalling device to indicate the location of the object.
Inventors
- 👤 John E Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:16
CPC Classifications
G; G01; G01V; G01V15/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
140 words
A method for indicating the presence of a local magnetic field having an intensity greater than a predetermined value, comprising the steps of: subjecting a resilient ferrous member to a periodically fluctuating magnetic field to set said resilient member into reciprocating motion toward and away from a contact member adjacent to and normally spaced from said resilient member, indicating any actual engagement of said resilient member with said contact member resulting from the additional deflection force applied to said resilient member by said local magnetic field, first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member, and thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member whereby local fields of low intensity may be detected.
Claim 2
Independent Claim
140 words
A method for indicating the presence of a local magnetic field having an intensity greater than a predetermined value, comprising the steps of: subjecting a resilient ferrous member to a periodically fluctuating magnetic field to set said resilient member into reciprocating motion toward and away from a contact member adjacent to and normally spaced from said resilient member, indicating any actual engagement of said resilient member with said contact member resulting from the additional deflection force applied to said resilient member by said local magnetic field, first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member, and thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member whereby local fields of low intensity may be detected.
Claim 3
Independent Claim
172 words
A method comprising the steps of: fixedly holding an elongated, resilient, ferromagnetic electrically conductive member at one end whereby an opposing eNd of said resilient member is suspended in cantilever fashion adjacent to but normally spaced from said contact member, subjecting said resilient member to a periodic magnetic field such that said resilient member is cyclically deflected toward and away from said contact member, first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member, thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member into engagement with said contact member whereby said apparatus may be adjusted to detect local fields of low intensity, and indicating the presence of any additional magnetic field which additively co-acts with said periodic field to deflect said resilient member into engagement with said contact member in response to the completion of an electric circuit path through said resilient member and said contact member.
Claim 4
Independent Claim
172 words
A method comprising the steps of: fixedly holding an elongated, resilient, ferromagnetic electrically conductive member at one end whereby an opposing eNd of said resilient member is suspended in cantilever fashion adjacent to but normally spaced from said contact member, subjecting said resilient member to a periodic magnetic field such that said resilient member is cyclically deflected toward and away from said contact member, first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member, thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member into engagement with said contact member whereby said apparatus may be adjusted to detect local fields of low intensity, and indicating the presence of any additional magnetic field which additively co-acts with said periodic field to deflect said resilient member into engagement with said contact member in response to the completion of an electric circuit path through said resilient member and said contact member.
Claim 5
Dependent Claim
174 words
Detecting apparatus for indicating the presence of a local magnetic field having an intensity greater than a pre-determined value, said apparatus comprising in combination, a resilient ferrous member, a contact member positioned adjacent to and normally spaced from said resilient member, deflection means for subjecting said resilient member to a periodically fluctuating magnetic field to set said resilient member into reciprocating motion toward and away from said contact member, means for indicating the time duration during each cycle when said resilient member is in engagement with said contact member resulting from the additional deflection force applied to said resilient member by said local magnetic field, and control means for first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member and for thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member into engagement with said contact member whereby said apparatus may be adjusted to detect local fields of low intensity.
Claim 6
Dependent Claim
174 words
Detecting apparatus for indicating the presence of a local magnetic field having an intensity greater than a pre-determined value, said apparatus comprising in combination, a resilient ferrous member, a contact member positioned adjacent to and normally spaced from said resilient member, deflection means for subjecting said resilient member to a periodically fluctuating magnetic field to set said resilient member into reciprocating motion toward and away from said contact member, means for indicating the time duration during each cycle when said resilient member is in engagement with said contact member resulting from the additional deflection force applied to said resilient member by said local magnetic field, and control means for first increasing the magnitude of said periodically fluctuating field to a level adequate to deflect said resilient member into periodic engagement with said contact member and for thereafter reducing the intensity of said fluctuating field to a level no longer adequate to deflect said resilient member into engagement with said contact member whereby said apparatus may be adjusted to detect local fields of low intensity.
References Cited (Backward Citations)
US3321702A
Cited
US3349323A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |