US3684380A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Navigational aid comprising two mirrors mounted at predetermined angular relationship for reverse direction observation
Assignee: Individual
•
Filing: 1970-11-27
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Granted: 1972-08-15
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Expires: 1990-11-27
Abstract
Abstract Two-way vision mirrors comprising two mirrors mounted at right angles are provided with two indicator lines which when visually aligned provide sights 180* apart. In order to determine a craft''s position at sea by visual methods the pilot must be able to take relative bearings on landmarks or other aids to navigation when the ship is heading on a known course. If the object to be sighted is not too far from one side of the bow or the other and is ahead the pilot can sight ''''over the compass'''' and get a simultaneous reading of the ship''s heading and the object''s relative bearing. Next to knowing the ship''s exact heading, the most important bearings are the reciprocal, those to the rear. However, it has not been possible hitherto for a lone pilot at a fixed position, with the compass in full view, to obtain simultaneous bearings ahead and astern.
Inventors
- 👤 Robert Benchley Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:35
CPC Classifications
G; G02; G02B; G02B23/00; G02B23/02; G02B23/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
84 words
A navigational device including, in combination; means for holding said mirrors at a predetermined angle to each other and with their near edges spaced apart sufficiently to prevent an observer from seeing his own reflection; and an index mark on each of said mirrors equidistant from the intersection of the projected planes of said mirrors which when viewed with one eye from one of said mirrors at a position where said marks are visually aligned provides a reflected view along a predetermined rearward direction.
Claim 2
Dependent Claim
84 words
A navigational device including, in combination; means for holding said mirrors at a predetermined angle to each other and with their near edges spaced apart sufficiently to prevent an observer from seeing his own reflection; and an index mark on each of said mirrors equidistant from the intersection of the projected planes of said mirrors which when viewed with one eye from one of said mirrors at a position where said marks are visually aligned provides a reflected view along a predetermined rearward direction.
Claim 3
Dependent Claim
17 words
A navigational device as set forth in claim 1; wherein said predetermined angle is substantially 90* .
Claim 4
Dependent Claim
30 words
A navigational device a set forth in claim 1; and including adjustable mounting means for said mirrors providing angle and tilt adjustments while maintaining said predetermined angle between said mirrors.
Claim 5
Dependent Claim
100 words
A navigational device including, in combination, two mirrors; means for holding said mirrors at a predetermined angle to each other; an index mark on each of said mirrors at predetermined positions such that viewed from one of said mirrors at a position where said marks are visually aligned provides a reflected view from the other of said mirrors along a predetermined rearward direction; and including collapsible mounting means providing two preset positions; one of said positions being with the mirrors at said predetermined angle; and the other of said positions being a carrying position with said mirrors collapsed together face-to-face.
Claim 6
Dependent Claim
100 words
A navigational device including, in combination, two mirrors; means for holding said mirrors at a predetermined angle to each other; an index mark on each of said mirrors at predetermined positions such that viewed from one of said mirrors at a position where said marks are visually aligned provides a reflected view from the other of said mirrors along a predetermined rearward direction; and including collapsible mounting means providing two preset positions; one of said positions being with the mirrors at said predetermined angle; and the other of said positions being a carrying position with said mirrors collapsed together face-to-face.
Claim 7
Dependent Claim
17 words
A navigational device as set forth in claim 1; and including a rotatable mounting for said mirrors.
Claim 8
Dependent Claim
21 words
A navigational device as set forth in claim 5; wherein said rotatable mounting includes means for indicating the angle of rotation.
Claim 9
Dependent Claim
16 words
A navigational device as set forth in claim 1; wherein said predetermined direction is substantially 180*.
Claim 10
Dependent Claim
21 words
A navigational device as set forth in claim 1; wherein said reflected view is substantially 180* from the direct view direction.
Claim 11
Dependent Claim
36 words
A navigational device as set forth in claim 1; wherein said holding means provides for holding said mirrors at said predetermined angle and also permits folding said mirrors toward each other into a compact face-to-face position.
References Cited (Backward Citations)
US2374956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |