Patent US3727177A successfully refreshed from Google Patents.
US3727177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Short schuler attitude/heading reference system
Assignee: United States Department of the Navy
•
Filing: 1971-11-24
•
Granted: 1973-04-10
•
Expires: 1991-11-24
Abstract
Abstract A pair of sensors each responsive to changes in the earth''s magnetic field are orthogonally mounted with respect to each other and suitably electrically connected and pumped to provide signals representative of their heading. Mounting the two sensors each on a separate bob of a compound pendulum minimizes inductive mutual coupling and erroneous signals while the pendulum serves as a stable vertical reference from which the relative orientation of the chips are determined. Suspending a sonobuoy carrying the compound pendulum and sensors a considerable distance below the water surface from a sparbuoy via an elastic line tends to block the transfer of vertical and lateral accelerations to ensure that the compound pendulum provides a more stable vertical reference.
Inventors
- 👤 F Fuller
- 👤 D Walters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:35
CPC Classifications
B; B63; B63B; B63B49/00; G; G01; G01C; G01C17/00; G01C17/02; G01C17/28; G01C17/30; G01R; G01R33/00; G01R33/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
An apparatus for providing signals representative of the directional orientation of a sonobuoy comprising: a framework defining a first and a second axis orthogonally disposed with respect to each other and being pivotally secured along the first axis to the sonobuoy; a cross member laterally traversing and being pivotally secured to said framework in line with the second axis; a compound pendulum secured to said cross member at the point of intersection of the first and the second orthogonal axis to define a pendulum fulcrum including, a first bob carried on the end of a moment arm joined at its opposite end to said pendulum fulcrum, and a second bob carried on the end of a moment arm joined at its opposite end to said pendulum fulcrum and being aligned with the moment arm of said first bob; and a sensor element carried on both said first bob and on said second bob responsive to changes in the earth''s magnetic field to provide representative signals indicative of said directional orientation of said sonobuoy.
Claim 2
Independent Claim
173 words
An apparatus for providing signals representative of the directional orientation of a sonobuoy comprising: a framework defining a first and a second axis orthogonally disposed with respect to each other and being pivotally secured along the first axis to the sonobuoy; a cross member laterally traversing and being pivotally secured to said framework in line with the second axis; a compound pendulum secured to said cross member at the point of intersection of the first and the second orthogonal axis to define a pendulum fulcrum including, a first bob carried on the end of a moment arm joined at its opposite end to said pendulum fulcrum, and a second bob carried on the end of a moment arm joined at its opposite end to said pendulum fulcrum and being aligned with the moment arm of said first bob; and a sensor element carried on both said first bob and on said second bob responsive to changes in the earth''s magnetic field to provide representative signals indicative of said directional orientation of said sonobuoy.
Claim 3
Dependent Claim
36 words
An apparatus according to claim 1 in which the sensor elements are permalloy chips each having their easy axis orthogonally oriented with respect to each other for eliminating phase and amplitude ambiguities in said representative signals.
Claim 4
Dependent Claim
54 words
An apparatus according to claim 2 further including: a pumping coil coaxially disposed about each permalloy chip for inducing a low power magnetic field; and a sensor coil carried in the proximity of each permalloy chip inductively responsive to said low power magnetic field and the earth''s magnetic field to provide said representative signals.
Claim 5
Dependent Claim
39 words
An apparatus according to claim 3 in which the moment ratio attributed to said first bob about said pendulum fulcrum with respect to said second bob about said pendulum fulcrum approaches unity ensuring vertical stability of said compound pendulum.
Claim 6
Dependent Claim
36 words
An apparatus according to claim 4 in which said apparatus is suspended from and remotely disposed from a sparbuoy at the water''s surface to minimize the transfer of vertical and lateral accelerations to said compound pendulum.
Claim 7
Dependent Claim
28 words
An apparatus according to claim 5 in which said apparatus is suspended from said sparbuoy by an elastic support for damping said transfer of vertical and lateral accelerations.
Claim 8
Dependent Claim
30 words
An apparatus according to claim 3 wherein said permalloy chips are each characterized by a minor hysteresis loop and wherein said sensor elements are pumped around said minor hysteresis loops.
Claim 9
Dependent Claim
99 words
A stable suspension system in marinE applications for an electronic compass sensor of the type used to provide directional orientation signals with respect to the earth''s magnetic poles, comprising: a compound pendulum including a moment arm having a given period and a pivot therefor, for providing a vertical reference for said system; a simple pendulum having a period which is a large fraction of the given period of said compound pendulum; means suspending the pivot of said compound pendulum from said simple pendulum; and means mounting a directional magnetic field sensor on the moment arm of said compound pendulum.
Claim 10
Dependent Claim
99 words
A stable suspension system in marinE applications for an electronic compass sensor of the type used to provide directional orientation signals with respect to the earth''s magnetic poles, comprising: a compound pendulum including a moment arm having a given period and a pivot therefor, for providing a vertical reference for said system; a simple pendulum having a period which is a large fraction of the given period of said compound pendulum; means suspending the pivot of said compound pendulum from said simple pendulum; and means mounting a directional magnetic field sensor on the moment arm of said compound pendulum.
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) | 1976-04-09 | 1976-10-09 | 1977-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-09 | 1980-10-09 | 1981-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-09 | 1984-10-09 | 1985-04-10 | $7700.00 | Window Closed / Lapsed |