The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 31, 1984
Filed:
Jul. 15, 1981
Applicant:
Inventor:
Thomas D Davies, Potomac, MD (US);
Assignee:
Davis Instruments Corporation, San Leandro, CA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01C / ;
U.S. Cl.
CPC ...
356144 ; 356145 ; 33282 ;
Abstract
An optical device for vertically positioning a sextant to minimize the 'tilt error' which occurs in a measured angle of altitude whenever the sextant is not held orthogonal to the horizon. The optical device can be fixed to the sextant and provides in the sextant's viewing area a secondary horizon which will align with the direct horizon only when the sextant is in a vertical orientation. The device is capable of periodic calibration and can be pivoted out of the line of sight when the sextant's user is initially locating the celestial body whose altitude is being measured.