US4090070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solar pointer
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1977-03-17
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Granted: 1978-05-16
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Expires: 1997-03-17
Abstract
Abstract Two pyrheliometers each carry out periodic scanning in a plane at right angles to one of the two perpendicular axes of pivotal displacement of the solar pointer. Each pyrheliometer is associated with means for measuring the angular difference between the direction of the sun projected on the scanning plane and the direction of the pointing axis projected on the same plane and for delivering a pointing error signal which is proportional to the angular difference. The error signal obtained in each scanning plane is applied to a motor for the pivotal displacement of the pointer so that the pointing axis is directed towards the sun when both error signals have been cancelled.
Inventors
- 👤 Jacques Colomes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:22
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/78; G01S3/782; G01S3/785; G01S3/786; G01S3/7861; F; F24; F24S; F24S30/00; F24S30/40; F24S30/45; F24S30/455; F24S50/00; F24S50/20
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
182 words
A solar pointer which is capable of pivoting about two perpendicular axes, each pivotal movement being controlled by a motor, wherein said pointer comprises two pyrheliometers for carrying out in each case periodic scanning in a plane at right angles to one of the two pivotal axes aforesaid, each pyrheliometer being provided with a receiving unit which rotates about an axis at right angles to the scanning plane and being associated with means for measuring the angular difference between the direction of the sun projected on the scanning plane and the direction of the pointing axis projected on said plane and for delivering an electrical pointing error signal which is proportional to said angular difference, said error signal being applied to the motor which serves to drive the pointer in pivotal motion about the axis located at right angles to the scanning plane in order to cancel said error signal and cause the two directions to coincide in the scanning plane, the pointing axis of the pointer being then directed towards the sun when the two error signals have thus been cancelled.
Claim 2
Dependent Claim
182 words
A solar pointer which is capable of pivoting about two perpendicular axes, each pivotal movement being controlled by a motor, wherein said pointer comprises two pyrheliometers for carrying out in each case periodic scanning in a plane at right angles to one of the two pivotal axes aforesaid, each pyrheliometer being provided with a receiving unit which rotates about an axis at right angles to the scanning plane and being associated with means for measuring the angular difference between the direction of the sun projected on the scanning plane and the direction of the pointing axis projected on said plane and for delivering an electrical pointing error signal which is proportional to said angular difference, said error signal being applied to the motor which serves to drive the pointer in pivotal motion about the axis located at right angles to the scanning plane in order to cancel said error signal and cause the two directions to coincide in the scanning plane, the pointing axis of the pointer being then directed towards the sun when the two error signals have thus been cancelled.
Claim 3
Dependent Claim
79 words
A solar pointer according to claim 1, wherein each pyrheliometer comprises a hollow tube driven by suitable means in a uniform movement of rotation about its axis and optical means rigidly fixed to said tube and oriented in the direction of the sun at each revolution so that the sun's rays received by said means are directed through said tube to a photoelectric receiver which delivers an electrical pulse or so-called measuring pulse at each revolution of said tube.
Claim 4
Dependent Claim
74 words
A solar pointer according to claim 2, wherein said pointer comprises means for delivering an electrical pulse or so-called reference pulse when said optical means rigidly fixed to the hollow rotating tube are oriented in the direction of the pointing axis of the pointer, the error signal being accordingly constituted by a signal which is proportional to the time interval between the instants of appearance of the measuring pulse and of the reference pulse.
Claim 5
Dependent Claim
82 words
A solar pointer according to claim 3, wherein the means for delivering the reference pulse comprise a light source and a photoelectric detector aligned in parallel relation to the pointing axis of the pointer and a collimation system placed between the source and the detector and driven in the same movement of rotation as the hollow tube, the receiver being intended to receive the light emitted by said source at each revolution of the tube and then to deliver said reference pulse.
Claim 6
Dependent Claim
35 words
A solar pointer according to claim 4, wherein the collimation system is constituted by two diametrically opposite slits pierced in a hollow rotating cylinder which is rigidly fixed to the hollow tube of the pyrheliometer.
Claim 7
Dependent Claim
42 words
A solar pointer according to claim 2, wherein at least one of the pyrheliometers has a collimating slit of substantial length in the direction parallel to the axis of rotation of the hollow tube and of small width in the perpendicular plane.
Claim 8
Dependent Claim
54 words
A solar pointer according to claim 2, wherein the optical means which are rigidly fixed to the hollow rotating tube of each pyrheliometer are constituted by a mirror which is inclined to the axis of rotation of the tube and from which the sun's rays are reflected within the tube towards an optical duct.
Claim 9
Dependent Claim
23 words
A solar pointer according to claim 1, wherein the axis of rotation of one of the pyrheliometers is parallel to the earth's axis.
Claim 10
Dependent Claim
42 words
A solar pointer according to claim 6, wherein the pyrheliometer whose axis of rotation is parallel to the earth's axis is provided with a collimating slit having an angular aperture which is larger than the seasonal variations in declination of the sun.
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) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |