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US3593258A Expired / Lapsed US ⏱️ 0.0 years remaining

Dual magnetic circuit low leakage geophone

Assignee: Mandrel Industries Inc
•
Filing: 1969-08-15
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Granted: 1971-07-13
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Expires: 1989-08-15
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Abstract

Abstract A geophone for detecting seismic energy wherein a pair of cylindrical magnets are coaxially mounted within a hollow cylindrical, magnetically permeable housing with a first set of like polarity pole faces of the magnets in spaced apart confronting relationship centrally of the housing and the remaining like poles in flux communication with opposite enclosed ends of the housing to form an air gap extending from the confronting poles to the surrounding interior housing wall. A sensing coil of hollow cylindrical shape is mounted for coaxial and resilient reciprocation in the air gap region, and the flux emanating from each of the confronting pole faces is forced by the mutual repulsion between such like poles to assume a radial path effectively traversing the coil, thereby minimizing undesirable flux leakage and consequently increasing the electrical output from the coil.

Inventors

  • 👤 Clyde M Slavens

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 08:36
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/16; G01V1/18; G01V1/181

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 98 words
A transducer for converting seismic vibrations into electrical energy, comprising; a housing formed of a magnetically permeable material and having a substantially enclosed internal chamber, a pair of magnets having a first pair of like poles separately affixed to spaced-apart portions of the interior wall of said housing chamber and a second pair of like poles disposed in proximate and confronting relationship and in spaced-apart adjacency with the interior walls of said chamber to define a free space region of magnetic field therebetween, and coil means resiliently supported in said region in flux cutting relationship with the field.
Claim 2
Dependent Claim 98 words
A transducer for converting seismic vibrations into electrical energy, comprising; a housing formed of a magnetically permeable material and having a substantially enclosed internal chamber, a pair of magnets having a first pair of like poles separately affixed to spaced-apart portions of the interior wall of said housing chamber and a second pair of like poles disposed in proximate and confronting relationship and in spaced-apart adjacency with the interior walls of said chamber to define a free space region of magnetic field therebetween, and coil means resiliently supported in said region in flux cutting relationship with the field.
Claim 3
Dependent Claim 81 words
The transducer as defined in claim 1, wherein said housing is of cylindrical form having enclosed ends, said magnets are of annular form and the first pair of like poles are individually coaxially affixed to the interior walls of opposite ends of said housing and the second pair of said like poles are disposed generally centrally of said chamber, and said coil means comprising an annular winding coaxially mounted with and between said magnets and housing for axial reciprocation relative thereto.
Claim 4
Dependent Claim 57 words
The transducer as defined in claim 2, wherein said housing comprises an annular pole piece disposed circumferentially adjacent the second pair of like poles and projecting radially inwardly from portions of the interior housing wall adjacent the axial ends of said chamber to define an annular section of minimum radial separation between said magnets and said housing.
Claim 5
Dependent Claim 61 words
The transducer as defined in claim 3, wherein said magnets are of cylindrical form and said housing pole piece is formed with a internal cylindrical wall radially surrounding and axially bridging the second pair of like poles and said winding being of hollow cylindrical configuration and coaxially nested between said pole pieCe wall and the radially outer walls of said magnets.
Claim 6
Dependent Claim 19 words
The transducer as defined in claim 4, wherein said pole piece wall and said winding are substantially axially coextensive.
Claim 7
Dependent Claim 43 words
The transducer as defined in claim 4, wherein said winding has an axial dimension substantially equal to that of said pole piece wall and spring means mounted between each axial end of said winding and said housing to provide resilient axial reciprocation therebetween.

References Cited (Backward Citations)

US3100292A Cited
US3412376A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-07-12 1975-01-11 1975-07-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-07-12 1979-01-11 1979-07-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-07-12 1983-01-11 1983-07-13 $7700.00 Window Closed / Lapsed

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