US3831286A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Navigational apparatus
Assignee: BAE Systems PLC
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Filing: 1973-06-11
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Granted: 1974-08-27
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Expires: 1993-06-11
Abstract
Abstract The invention provides navigational apparatus in which the power supply for a detector measuring the magnetic heading of the vehicle to which the apparatus is fitted, is effectively isolated from the power supply for other components of the apparatus and is stabilised with the result that the overall accuracy of the apparatus is improved considerably even though the power supply for said other components may be relatively unstable. A preferred arrangement comprises gyroscopic means operable to detect changes in heading of the vehicle and produce an electrical output signal in accordance therewith, drive means operable to drive a shaft of a heading indicator in response to the output signal from the gyroscopic means, a detector operable to measure the magnetic heading of the vehicle and to produce an A.C. output signal in accordance therewith, a demodulator operable to produce a D.C. output signal from the A.C. output signal of the detector, logic circuitry to produce a pulsed output signal in response to the D.C. output signal from the demodulator, and a stepper motor to which is applied the pulsed output signal from the logic circuitry and which drives the shaft of the heading indicator to compensate the latter for changes in the magnetic heading of the vehicle, electrical power for the detector and the demodulator being derived from a first stablized A.C. supply which is effectively voltage and frequency independent of a second A.C. supply for at least the gyroscopic device and the drive means.
Inventors
- 👤 D Conibear
- 👤 M Halls
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 04:37
CPC Classifications
G; G01; G01C; G01C17/00; G01C17/36
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
178 words
Vehicle mounted navigation apparatus comprising detector means operable to measure the magnetic heading of said vehicle and producing an electrical output signal in accordance therewith, heading data transmission means coupled to said detector means for indicating heading of said vehicle, means including demodulator means responsive to said electrical output signal from said detector means and coupled to said heading data transmission means for providing output signals in accordance with the difference between said measured magnetic heading of said vehicle and said indicated heading of said vehicle, means coupled to said heading data transmission means and responsive to said difference output signals for driving said heading data transmission means to provide a corrected indicated heading of said vehicle in accordance with said measured magnetic heading, first A.C. power supply means for providing electrical power to said navigation apparatus, and second A.C. power supply means for providing stabilized electrical power to said detector means and said demodulator means whereby said stabilized electrical power is effectively voltage and frequency independent of said electrical power from said first A.C. power supply means.
Claim 2
Dependent Claim
178 words
Vehicle mounted navigation apparatus comprising detector means operable to measure the magnetic heading of said vehicle and producing an electrical output signal in accordance therewith, heading data transmission means coupled to said detector means for indicating heading of said vehicle, means including demodulator means responsive to said electrical output signal from said detector means and coupled to said heading data transmission means for providing output signals in accordance with the difference between said measured magnetic heading of said vehicle and said indicated heading of said vehicle, means coupled to said heading data transmission means and responsive to said difference output signals for driving said heading data transmission means to provide a corrected indicated heading of said vehicle in accordance with said measured magnetic heading, first A.C. power supply means for providing electrical power to said navigation apparatus, and second A.C. power supply means for providing stabilized electrical power to said detector means and said demodulator means whereby said stabilized electrical power is effectively voltage and frequency independent of said electrical power from said first A.C. power supply means.
Claim 3
Dependent Claim
64 words
Vehicle mounted navigation apparatus as recited in claim 1 further including a gyroscopic device coupled to said data transmission means thereby being slaved to said detector means and being operable to detect changes in the heading of said vehicle and providing output electrical signals in accordance therewith which are coupled to said heading data transmission means to drive said heading data transmission means accordingly.
Claim 4
Dependent Claim
65 words
Vehicle mounted navigation apparatus as recited in claim 2 in which said means for providing difference output signals includes logic circuitry coupled to a stepper motor whereby said logic circuitry produces a pulsed output signal in response to said difference output signals that is applied to said stepper motor for driving said heading data transmission means which is short term stabilized by said gyroscopic means.
Claim 5
Dependent Claim
221 words
Vehicle mounted navigation apparatus comprising gyroscopic means for detecting the changes in heading of said vehicle and producing an electrical output signal in accordance therewith, heading indicator means, data transmission means including a shaft coupled to said heading indicator means, drive means responsive to said output signal from said gyroscopic means and coupled to said shaft for driving said shaft in response to the output signal from said gyroscopic means, detector means for measuring the magnetic heading of said vehicle and producing an A.C. output signal in accordance therewith, demodulator means coupled to said detector means for producing a D.C. output signal from said A.C. output signal of said detector means, logic circuit means coupled to said demodulator means for producing a pulsed output signal in response to said D.C. output signal from said demodulator means, a stepper motor coupled between said logic circuit means and said heading data transmission means for driving said shaft to compensate for changes in magnetic heading of said vehicle, first A.C. power supply means for providing electrical power at least for said gyroscopic device and said drive means and second stabilized A.C. power supply means for providing electrical power to said detector means and said demodulator means which is effectively voltage and frequency independent of said electrical power from said first A.C. power supply means.
Claim 6
Dependent Claim
221 words
Vehicle mounted navigation apparatus comprising gyroscopic means for detecting the changes in heading of said vehicle and producing an electrical output signal in accordance therewith, heading indicator means, data transmission means including a shaft coupled to said heading indicator means, drive means responsive to said output signal from said gyroscopic means and coupled to said shaft for driving said shaft in response to the output signal from said gyroscopic means, detector means for measuring the magnetic heading of said vehicle and producing an A.C. output signal in accordance therewith, demodulator means coupled to said detector means for producing a D.C. output signal from said A.C. output signal of said detector means, logic circuit means coupled to said demodulator means for producing a pulsed output signal in response to said D.C. output signal from said demodulator means, a stepper motor coupled between said logic circuit means and said heading data transmission means for driving said shaft to compensate for changes in magnetic heading of said vehicle, first A.C. power supply means for providing electrical power at least for said gyroscopic device and said drive means and second stabilized A.C. power supply means for providing electrical power to said detector means and said demodulator means which is effectively voltage and frequency independent of said electrical power from said first A.C. power supply means.
Claim 7
Dependent Claim
28 words
Vehicle mounted navigation apparatus as recited in claim 4 which further incluDes a common power source for providing power to said first and second A.C. power supply means.
Claim 8
Dependent Claim
50 words
Vehicle mounted navigation apparatus as recited in claim 5 in which said common power supply source is a source of A.C. power and further includes converter means for converting said A.C. power into D.C. power and said first and second A.C. power supply means are coupled to said converter means.
Claim 9
Dependent Claim
21 words
Vehicle mounted navigation apparatus as recited in claim 5 in which said common power supply source includes a D.C. power supply.
Claim 10
Dependent Claim
53 words
Vehicle mounted navigation apparatus as recited in claim 4 in which said second stabilized A.C. power supply means includes means for limiting variations in frequency and voltages of said second stabilized A.C. power supply means to within one-half of the variations in frequency and voltage present in said first A.C. power supply means.
Claim 11
Dependent Claim
43 words
Vehicle mounted navigation apparatus as recited in claim 8 in which said second stabilized A.C. power supply means includes means for limiting variations in frequency and voltage to less than 20 per cent of those occurring in said first A.C. power supply means.
Claim 12
Dependent Claim
22 words
Vehicle mounted navigation apparatus as recited in claim 4 in which said second stabilized A.C. power supply means includes stabilized inverter means.
Claim 13
Dependent Claim
18 words
Vehicle mounted navigation apparatus as recited in claim 4 in which said detector means includes a flux valve.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |