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:
Feb. 26, 1980
Filed:
Oct. 19, 1977
Pierre A Moulin, Chaville, FR;
Schlumberger Technology Corporation, New York, NY (US);
Abstract
Method and apparatus for automatically inscribing magnetic marks on a moving wireline are disclosed. An alternating magnetic field is generated for application to a zone on the moving wireline. The marks are inscribed on the wireline by interrupting the field in response to a control signal corresponding to the time for a mark. The interruption is synchronized to alternations of the field and movement of the wireline. The interruption begins between alternations of the field and is maintained for a time sufficient for a predetermined length of the wireline to be moved beyond the application zone. This predetermined length is related to the length of the zone on the wireline affected by the alternating magnetic field, which is applied with a U-shaped electromagnet held in proximity to the wireline. Wireline movement pulses are generated by a tangentially coupled measuring wheel driving an encoder. The movement pulses are counted to determine the time for each mark and provide a control signal corresponding to a desired mark. The pulses are also used to determine when the predetermined length of wireline has been moved beyond the application zone and when the interruption of the field ends. Preferably, the field is restored starting with an alternation of a polarity related to the polarity of the field when it was terminated.