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:
Sep. 03, 1991
Filed:
Nov. 17, 1989
Applicant:
Inventors:
Armond D Cosman, Austin, TX (US);
Joe T Minarovic, Austin, TX (US);
David C Worboys, Austin, TX (US);
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Primary Examiner:
Int. Cl.
CPC ...
B32B / ; F16L / ;
U.S. Cl.
CPC ...
428 341 ; 428 77 ; 405157 ; 324326 ; 156 68 ;
Abstract
A marked conduit allowing electronic location of the conduit after burial, having a plurality of electronic markers spaced thereon at predetermined intervals. The distance between the markers encodes information about the buried conduit. The markers are preferably passive circuits tuned to a specific frequency. The markers may be oriented in a predetermined pattern to encode additional information, and may be attached to the outer or inner surface of the conduit, or imbedded in the wall of the conduit.