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:
Oct. 10, 1989
Filed:
Oct. 09, 1987
Applicant:
Inventor:
Tomoyasu Oike, Sagamihara, JP;
Assignee:
Minnesota Mining and Manufacturing Company, St. Paul, MN (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01Q / ; H01Q / ;
U.S. Cl.
CPC ...
343744 ; 343719 ; 324329 ; 340572 ;
Abstract
A marker for positioning near a buried object wherein the marker can be detected to locate the buried object. The marker includes a passive resonant type antenna which becomes inoperative when the initial position for the buried marker is changed. A lead wire and/or a mercury switch that is a part of the antenna serve to make the antenna inoperative due to such change in the initial position of the marker.