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. 07, 1976
Filed:
Jun. 12, 1975
Applicant:
Inventor:
David James Martin, Leatherhead, EN;
Assignee:
Coal Industry (Patents) Limited, London, EN;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
325-4 ; 325 51 ;
Abstract
A telecommunication system used in a mine has a long aerial along a tunnel which radiates signals to a mobile station. Signals from the station are radiated back to the line. Repeaters are included along the line to make up power losses. A connection of an extra length of line is made on the output side of each repeater and extends back parallel to the line for a distance of up to half the distance between adjacent repeaters. This extra line reduces the attenuation of signal power between repeaters.