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:
Aug. 22, 1989
Filed:
Mar. 10, 1988
Applicant:
Inventor:
Mujib Rahman, Columbia, SC (US);
Assignee:
Pirelli Cable Corporation, Florham Park, NJ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; H01J / ; H01B / ; G08B / ;
U.S. Cl.
CPC ...
350 9623 ; 350 9610 ; 250227 ; 2502 / ; 174 / ; 174 / ; 340541 ; 340544 ; 340632 ;
Abstract
An optical fiber cable with optical fibers surrounded by a first gas blocking layer which is surrounded by a second gas blocking layer spaced from the first layer so as to provide longitudinal gas flow channels between the first and second layers. The channels are filled with a gas under a pressure above atmospheric pressure so that when the second layer is punctured, there is a gas flow and/or gas pressure drop indicating such puncturing and hence, if caused by tampering, the fact of tampering. Also, devices for indicating the gas flow and/or pressure drop and alarms and/or signal transmission terminating apparatus responsive to such devices.