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:
Mar. 26, 1985
Filed:
Mar. 10, 1982
Jurgen Flach, deceased, late of Duesseldorf, DE;
Rigobert Opitz, Hamburg, DE;
Heinz Daugart, Nienhof, DE;
Hans-Gunter Baden, Munster, DE;
Rheinmetall GmbH., Duesseldorf, DE;
Abstract
Method for determining the position and depth of unevenness in an inner surface of a pipe with the aid of a scanning head which is adapted to travel through the pipe and which is rotatable about the pipe axis. The invention provides an inductive, or capacitive, depth scanning process, which operates in a contact-free manner with respect to the inner pipe surface. This is attained by means of an inductive method in that, as is illustrated in the drawing, there is arranged at a distance from the pipe inner surface the scanning head which is guided and in which a coil (2) of a measuring, resonant circuit is mounted and, above the inner periphery of the pipe, a coil 1 of a reference, resonant circuit is arranged, and then, after the frequencies of both resonant circuits have been brought, prior to measuring, to an identical value in each of a multiplying circuit (10, 7, 13 respectively 11, 8, 14), they are measured and converted into an adjustable difference of the multiplied frequencies (f.sub.1, f.sub.2) in an analog-digital converter (18) and conducted to a microprocessor ( 19) as a signal with respect to the unevenness, and from there are conducted to an evaluation unit (20). With the capacitative depth scanning method, the frequency difference is attained by adjusting the capacity of the resonant circuits.