US3764220A
Expired / Lapsed
US
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Alignment apparatus using a laser having a gravitationally sensitive cavity reflector
Assignee: National Aeronautics and Space Administration
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Filing: 1971-07-30
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Granted: 1973-10-09
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Expires: 1991-07-30
Abstract
Abstract A device for determining a true gravitational vertical including a vertically disposed laser having a gravitationally sensitive lower regeneration reflector which enables an output beam to be developed only when the optical axis of the laser is disposed normal to the gravitationally sensitive reflective surface. In an alternative embodiment, the device is combined with a servo system to provide a gravitationally stabilized horizontal platform.
Inventors
- 👤 K Billman
- 👤 E Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:54
CPC Classifications
G; G01; G01C; G01C15/00; G01C15/10; G01C15/105; H; H01; H01S; H01S3/00; H01S3/05; H01S3/08
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
104 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors dispersed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition, said second mirror including a pool of liquid material having a surface reflectivity sufficient to enable lasing; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 2
Dependent Claim
104 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors dispersed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition, said second mirror including a pool of liquid material having a surface reflectivity sufficient to enable lasing; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 3
Dependent Claim
101 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said second mirror being buoyantly supported by said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 4
Dependent Claim
101 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said second mirror being buoyantly supported by said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 5
Dependent Claim
129 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirros defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said liquid being held within a container, said second mirror being attached to a support having a pointed base that rests on the floor of said container, said mirror and said support being immersed under said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 6
Dependent Claim
129 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirros defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said liquid being held within a container, said second mirror being attached to a support having a pointed base that rests on the floor of said container, said mirror and said support being immersed under said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 7
Dependent Claim
90 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition, said second mirror being damped with a highly viscous fluid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 8
Dependent Claim
90 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition, said second mirror being damped with a highly viscous fluid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 9
Dependent Claim
107 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonsant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said second mirror beiNg attached to a support which is partially immersed in said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 10
Dependent Claim
107 words
Alignment apparatus for establishing a true vertical reference in a gravitational field, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonsant cavity; said second mirror having a reflective surface which is oriented by said gravitational field to maintain a horizontal disposition; a body of liquid, said second mirror beiNg attached to a support which is partially immersed in said liquid; and means for positioning said first mirror parallel to said horizontal reflective surface whereby a vertical laser beam occurs.
Claim 11
Dependent Claim
15 words
Alignment apparatus as claimed in claim 3 wherein said liquid is impregnated with a dye.
Claim 12
Dependent Claim
99 words
Alignment apparatus for establishing a true vertical reference, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; a body of liquid; a container for holding said liquid; said second mirror being attached to a base, said base being partially immersed in and supported by said liquid whereby said second mirror is maintained horizontal; and means for positioning said mirror parallel to said second mirror whereby a vertical laser beam occurs.
Claim 13
Dependent Claim
99 words
Alignment apparatus for establishing a true vertical reference, comprising: a laser comprising a lasing element having first and second ends, a pumping source, and first and second mirrors disposed adjacent said first and second ends, respectively, said first and second mirrors defining an optically resonant cavity; a body of liquid; a container for holding said liquid; said second mirror being attached to a base, said base being partially immersed in and supported by said liquid whereby said second mirror is maintained horizontal; and means for positioning said mirror parallel to said second mirror whereby a vertical laser beam occurs.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |