Patent US3579846A successfully refreshed from Google Patents.
US3579846A
Expired / Lapsed
US
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Laser gyrometer system
Assignee: Alcatel Lucent SAS
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Filing: 1967-12-15
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Granted: 1971-05-25
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Expires: 1987-12-15
Abstract
Abstract Variation of output frequency of a laser gyrometer, the plane of which rotates about a vertical axis, is utilized to ascertain the direction of geographical North. Adequate mechanical construction reduces several inaccuracies to a minimum.
Inventors
- 👤 Jean-Michel Catherin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:21
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/083
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
178 words
Apparatus for determining a reference plane on a body rotating about a first axis, including: a laser gyrometer mounted on said body for rotation about a second axis such that the flux of the rotation vector of said body through the plane of said gyrometer varies with the angular position of said plane, drive means for rotating said gyrometer about said second axis, reference generating means having a portion mounted for rotation with said gyrometer and a portion fixed relative to said body for providing a reference output signal, discriminator means connected to the output of said gyrometer for converting the output beat frequency to a voltage, synchronous detector means connected to the output of said reference generating means and the output of said discriminator means for producing a signal indicative of the relative phase of said outputs, and means for moving a portion of said reference generating means that is fixed relative to said body for changing the phase of the output of said reference generating means to reduce said synchronous detector output signal to a null.
Claim 2
Dependent Claim
178 words
Apparatus for determining a reference plane on a body rotating about a first axis, including: a laser gyrometer mounted on said body for rotation about a second axis such that the flux of the rotation vector of said body through the plane of said gyrometer varies with the angular position of said plane, drive means for rotating said gyrometer about said second axis, reference generating means having a portion mounted for rotation with said gyrometer and a portion fixed relative to said body for providing a reference output signal, discriminator means connected to the output of said gyrometer for converting the output beat frequency to a voltage, synchronous detector means connected to the output of said reference generating means and the output of said discriminator means for producing a signal indicative of the relative phase of said outputs, and means for moving a portion of said reference generating means that is fixed relative to said body for changing the phase of the output of said reference generating means to reduce said synchronous detector output signal to a null.
Claim 3
Dependent Claim
17 words
Apparatus as claimed in claim 1, in which said second axis is located in said gyrometer plane.
Claim 4
Dependent Claim
46 words
Apparatus as claimed in claim 1 in which said reference generating means includes a light source disposed on a plate serving as a base support for said gyrometer, and at least one photosensitive element disposed on a member fixedly mounted at said position on said body.
Claim 5
Dependent Claim
14 words
Apparatus as claimed in claim 3, in which said light source is a laser.
Claim 6
Dependent Claim
22 words
Apparatus as claimed in claim 3, in which said fixedly mounted member includes means for varying its orientation relative to said position.
Claim 7
Dependent Claim
22 words
Apparatus as claimed in claim 5, in which said means for varying the orientation includes a gear train driven by a servomotor.
Claim 8
Dependent Claim
51 words
Apparatus as claimed in claim 1, in which said frequency discriminator is connected at its output to a band-pass filter, the characteristic curve of the discriminator being centered on the constant frequency of anisotropy, and the passband of said filter being centered on the frequency of rotation of said gyrometer plane.
Claim 9
Dependent Claim
32 words
Apparatus as claimed in claim 1, in which said drive means includes a gear train driven by a servomotor, said synchronous detector means being connected to control the operation of said servomotor.
Claim 10
Dependent Claim
83 words
Apparatus as claimed in claim 8, including a platform on which is mounted said gyrometer and which is rigidly attached to a shaft arranged to be driven by a motor and supported in two bearings, and further including means for providing a torque on the shaft whereby one generatrix of a cylinder enveloping the shaft is maintained in contact with a fixed point in one bearing, and the diametrically opposite generatrix is maintained in contact with a fixed point on the other bearing.
Claim 11
Dependent Claim
39 words
Apparatus as claimed in claim 9, in which said means for providing the torque on said shaft includes a support for said bearings arranged to locate the axis of rotation of said shaft at an angle to the vertical.
Claim 12
Dependent Claim
35 words
Apparatus as claimed in claim 1 including a platform on which is mounted said gyrometer and which is rigidly attached to a shaft arranged to be driven by a motor and supported in two bearings.
Claim 13
Dependent Claim
39 words
Apparatus as claimed in claim 11, in which said platform is provided with a turntable on which said gyrometer is rigidly fixed, and with a fixing means for locking said turntable in a predetermined position relative to said platform.
Claim 14
Dependent Claim
44 words
Apparatus as claimed in claim 11, in which said motor for driving said shaft is mounted with said shaft and its supports on a rotatable dIsc and in which means are provided for positioning said disc with respect to said position on said body.
Claim 15
Dependent Claim
40 words
Apparatus as claimed in claim 13, in which said means for positioning the disc includes a second servomotor and a gear-train positioned to rotate the disc about its axis which is fixed with respect to said position on said body.
Claim 16
Dependent Claim
62 words
Apparatus as claimed in claim 14, including a marker means for providing signals indicative of the position of said gyrometer plane relative to said position on said body, including said synchronous detector means for comparing the frequency measured by said discriminator means with the frequency of the signal generated by said marker means, said servomotor being controlled by said synchronous detector means.
Claim 17
Dependent Claim
31 words
Apparatus as claimed in claim 15 in which the marker means includes an autocollimating telescope whose optical axis provides an indication of the gyrometer plane position yielding the preselected output position.
Claim 18
Dependent Claim
17 words
Apparatus as claimed in claim 16, in which said telescope is rigidly attached to said rotatable disc.
Claim 19
Dependent Claim
36 words
Apparatus as claimed in claim 16 in which the optical axis of the telescope, the axis of the gyrometer shaft and the lines of action of the forces providing torque on the gyrometer shaft are coplanar.
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |