US3752591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sextant with digital readout and night viewing capability
Assignee: United States Department of the Navy
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Filing: 1971-08-04
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Granted: 1973-08-14
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Expires: 1991-08-04
Abstract
Abstract A navigation instrument for measuring the altitude of celestial bodies above the horizon adaptable to use with ordinary iron sights, a standard telescope for daylight viewing, and an electronic image enhancing telescope for night viewing of the horizon. Digital readout of the altitude of the celestial bodies is available on the instrument as well as electrically telemetering this information to a remote site where it may be recorded along with the time of observation.
Inventors
- 👤 S Feldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:39
CPC Classifications
G; G01; G01C; G01C1/00; G01C1/08; G01C21/00; G01C21/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
153 words
A hand held sextant adaptable for day and night use comprising: a box-shaped frame open at both ends along a line of sight; an electronic light enhancing telescope removably mounted in said frame along said line of sight; a horizon mirror affixed to said frame in optical alignment with said telescope; a gear train mounted on said frame; a tiltable index mirror coupled to said gear train in said line of sight; a digital read-out display indicator coupled to said gear train for indicating the tilt of said index mirror and thereby the angle of elevation of a celestial body, mounted on said frame above said telescope in facing relationship to the operator for viewing while operating said sextant; a time display indicator mounted adjacent and viewable simultaneously with said digital read-out display; and manual coarse and fine adjustment means coupled to said gear train for affecting the tilt of said index mirror.
Claim 2
Dependent Claim
153 words
A hand held sextant adaptable for day and night use comprising: a box-shaped frame open at both ends along a line of sight; an electronic light enhancing telescope removably mounted in said frame along said line of sight; a horizon mirror affixed to said frame in optical alignment with said telescope; a gear train mounted on said frame; a tiltable index mirror coupled to said gear train in said line of sight; a digital read-out display indicator coupled to said gear train for indicating the tilt of said index mirror and thereby the angle of elevation of a celestial body, mounted on said frame above said telescope in facing relationship to the operator for viewing while operating said sextant; a time display indicator mounted adjacent and viewable simultaneously with said digital read-out display; and manual coarse and fine adjustment means coupled to said gear train for affecting the tilt of said index mirror.
Claim 3
Dependent Claim
68 words
The sextant of claim 1 wherein said digital readout display indicator further includes: a shaft encoder coupled to said gear train to provide an output related to shaft rotation, and a remote digital display indicator connected to said shaft encoder to provide aN indication of the angle of elevation of a celestial body at a position remote from the sextant, a time display indicator mounted adjacent said display.
Claim 4
Dependent Claim
104 words
The sextant of claim 1 further comprising: a handgrip movably attached to said frame for balanced holding of said sextant in use; a pair of coarse adjustment knobs connected to said gear train; a pair of fine adjustment knobs connected to said gear train; whereby one of each pair is on opposite sides of said control and gear box for convenient use by both left- and right-handed operators; a set of horizon mirror filter shades in the line-of-sight of the horizon; a set of index mirror filter shades in the line-of-sight of the celestial body; and a pilot lamp adjacent said digital read-out indicator.
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) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |