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. 19, 1978
Filed:
Apr. 29, 1977
Applicant:
Inventors:
Ambroz K Skrovanek, Bethesda, MD (US);
Fred E Clark, Jr, Arlington, VA (US);
Assignee:
Harvey Hubbell Incorporated, Bridgeport, CT (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
1791702 ;
Abstract
An interface unit for a four wire telephone circuit includes an echo suppressor. A filter circuit is connected to the transmit line drop side to detect voice and SF signals and to selectively couple a regenerated SF signal and the voice signal to the line side of the transmit line. A passive filter is selectively coupled to the receive side to attentuate voice echo but bypass SF signals.