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:
Nov. 06, 1984
Filed:
Dec. 03, 1982
Harper E Sharp, Houston, TX (US);
Miles A Smither, Houston, TX (US);
Wilson Industries, Inc., Houston, TX (US);
Abstract
A borehole survey instrument and control circuitry are described. The borehole survey instrument includes indicators for measuring angle of deviation from the vertical and angle of deviation from magnetic north and a photographic recording means for recording the output of the indicators at selected times. A lighting system is utilized in conjunction with the photographic recording means to expose photographic film and a novel time control circuit is utilized in conjunction with the lighting system to alter the length of time of illumination in accordance with the operativeness of individual bulbs within the lighting system. In this manner, the failure of one or more bulbs within the lighting system will not substantially affect the amount of illumination to which the film in the photographic recording means is exposed.