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:
Jul. 19, 1983
Filed:
Apr. 19, 1982
Steven W Powell, Houston, TX (US);
James G Stockton, Houston, TX (US);
NL Sperry Sun, Inc., Sugar Land, TX (US);
Abstract
A surface activated multishot survey tool utilizes a dampened magnetic compass movably positioned within a probe to determine the direction of a borehole. Lamps in the probe are operable to light the face of the compass. A lens projects the image of the compass onto a movable film strip. An electrical cable is connected to the probe and is used to pass a current to the lamps and provide selective operation of the tool from the surface of the borehole. Electrical connectors are provided at each end of the probe so that the probe may be inverted within the borehole to accommodate surveys in which the angle of the borehole is greater than that at which the compass will operate without error. Because connectors are located at both ends of the probe, electrical current passes around the magnetic compass, thus creating a magnetic field about the compass. An alternating current is used to operate the tool, with the rate of change in direction of the current being faster than the movement response time of the dampened compass to the changing magnetic field generated by the current.