US3906339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for determining the angle between a rotatable body and a fixed coil system, having use in a compass system
Assignee: Fried Krupp AG
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Filing: 1974-07-31
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Granted: 1975-09-16
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Expires: 1994-07-31
Abstract
Abstract A system for deriving an electrical representation of an angle, which system includes two coils arranged to have their axes perpendicular to one another and connected to receive alternating excitation voltages which are identical except that the voltage to one coil is shifted in phase by 90* relative to the voltage to the other coil, whereby there is produced a magnetic field which rotates in the plane defined by the coil axes, and a positioning member located in the field and mounted for rotation about an axis perpendicular to the coil axes, the angle to be detected being between one of the coil axes and a reference axis fixed relative to the positioning member and extending perpendicular to the axis of rotation thereof. The positioning member includes a high magnetic permeability rod oriented at an angle to the axis of rotation of the positioning member and the system includes a stationary third coil surrounding the positioning member and oriented so that its axis is parallel to the axis of the positioning member. The rotating magnetic field produced by the two coils is distorted by the rod so that a portion of the field flux passes through the region enclosed by the third coil in a direction normal to the plane of the third coil, and induces in the third coil a voltage whose phase relative to the phase of the voltage in one of the two coils corresponds to the angle between the reference axis and the axis of that one coil.
Inventors
- 👤 Reinhard Leisterer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:45
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/12; G01D5/14; G01D5/20; G01D5/204; G01D5/2073; G01D5/208
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
295 words
In a device for deriving an electrical representation of a spatial angle, the device including a coil system composed of two coils arranged with their coil axes perpendicular to one another, a voltage source connected to apply to each coil a respective one of two alternating voltages of the same frequency and amplitude but shifted in phase with respect to one another by 90* for causing the two coils to produce a rotating magnetic field, and a positioning member mounted in the alternating magnetic field produced by the coil system to be rotatable about an axis of rotation perpendicular to the coil axes of the coil system, the spatial angle to be detected lying between a reference axis fixed relative to the positioning member and extending perpendicular to the axis of rotation thereof and one of the two coil axes, the improvement wherein: said positioning member comprises an elongate rod of high magnetic permeability material oriented with its longitudinal axis extending obliquely to the axis of rotation of said positioning member; and said device further comprises a third coil surrounding said positioning member and fixed relative to said two coils, said third coil oriented with its coil axis parallel to the axis of rotation of said positioning member; whereby a portion of the flux of the rotating magnetic field flows longitudinally through said rod to traverse the plane of said third coil, in a direction transverse to that plane, and induces, in said third coil, a voltage which differs in phase from the voltage applied to one of said two coils by an amount corresponding to the angle between the axis of that one of said two coils and the projection on the plane of said third coil of the longitudinal axis of said rod.
Claim 2
Dependent Claim
295 words
In a device for deriving an electrical representation of a spatial angle, the device including a coil system composed of two coils arranged with their coil axes perpendicular to one another, a voltage source connected to apply to each coil a respective one of two alternating voltages of the same frequency and amplitude but shifted in phase with respect to one another by 90* for causing the two coils to produce a rotating magnetic field, and a positioning member mounted in the alternating magnetic field produced by the coil system to be rotatable about an axis of rotation perpendicular to the coil axes of the coil system, the spatial angle to be detected lying between a reference axis fixed relative to the positioning member and extending perpendicular to the axis of rotation thereof and one of the two coil axes, the improvement wherein: said positioning member comprises an elongate rod of high magnetic permeability material oriented with its longitudinal axis extending obliquely to the axis of rotation of said positioning member; and said device further comprises a third coil surrounding said positioning member and fixed relative to said two coils, said third coil oriented with its coil axis parallel to the axis of rotation of said positioning member; whereby a portion of the flux of the rotating magnetic field flows longitudinally through said rod to traverse the plane of said third coil, in a direction transverse to that plane, and induces, in said third coil, a voltage which differs in phase from the voltage applied to one of said two coils by an amount corresponding to the angle between the axis of that one of said two coils and the projection on the plane of said third coil of the longitudinal axis of said rod.
Claim 3
Dependent Claim
31 words
An arrangement as defined in claim 1 wherein the longitudinal axis of said rod is oriented at an angle of approximately 45* to the axis of rotation of said positioning member.
Claim 4
Dependent Claim
30 words
An arrangement as defined in claim 1 wherein the longitudinal axis of said rod, the axis of rotation of said positioning member, and the reference axis lie in one plane.
Claim 5
Dependent Claim
34 words
An arrangement as defined in claim 1 wherein the reference axis is arranged perpendicular to a plane defined by the axis of rotation of said positioning member and the longitudinal axis of said rod.
Claim 6
Dependent Claim
25 words
An arrangement as defined in claim 1 wherein said positioning member further comprises a conical bearing via which it is supported to be freely rotatable.
Claim 7
Dependent Claim
26 words
An arrangement as defined in claim 5 wherein said positioning member further comprises a compass needle mounted to extend in the direction of the reference axis.
Claim 8
Dependent Claim
54 words
An arrangement as defined in claim 6 wherein: the longitudinal axis of said rod, the axis of rotation of said positioning member and the reference axis lie in one plane; said rod comprises two parallel partial rods; and said compass needle comprises two permanent magnets each mounted at a respective end of said rod.
Claim 9
Dependent Claim
22 words
An arrangement as defined in claim 7 wherein said magnets are polarized in the direction of the longitudinal axis of said rod.
Claim 10
Dependent Claim
23 words
An arrangement as defined in claim 7 wherein said rod and said magnets are made of ferrite materials producing low eddy current losses.
Claim 11
Dependent Claim
103 words
An arrangement as defined in claim 1 wherein each of said two coils is composed of two coaxial partial coils, and said arrangement further comprises a cylindrical coil body carrying said third coil and provided with a plurality of substantially axially directed grooves spaced apart by 45* around the circumference of said body, with opposed coil sides of each said partial coil being disposed in a respective pair of said grooves which are 135* apart and said paRtial coils of one of said two coils being oriented at an angle of 90* to said partial coils of the other of said two coils.
References Cited (Backward Citations)
US2588619A
Cited
US3699558A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |