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:
Dec. 16, 1986
Filed:
Sep. 25, 1984
Applicant:
Inventor:
David J Martin, Leatherhead, GB;
Assignee:
Coal Industry (Patents) Limited, London, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04R / ; B66B / ;
U.S. Cl.
CPC ...
342358 ; 340 21 ; 455 55 ; 342365 ;
Abstract
A leaky-feeder or other form of guided radiocommunication system serving a linear route or track is equipped at intervals with static marker devices which successively modify a radio signal passing those points between a fixed base station and a personal or mobile station travelling the route. By reference to the resulting overall modification to the signal as received at the mobile or fixed station the position of the mobile station may be determined or delimited.