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.

Date of Patent:
Apr. 07, 1981

Filed:

Jan. 30, 1979
Applicant:
Inventors:

Tsuyoshi Shinoi, Yokohamashi, JP;

Setsuo Oshima, Kawasaki, JP;

Assignees:

Nippon Tsushin Kogyo KK, Kawasaki, JP;

TIE/Communications, Inc., Shelton, CT (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04Q / ; H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ; 179 / ;
Abstract

A switching matrix in the key service unit of a key telephone system is formed by several groups of relays, each group being associated with a particular station set and each relay in each group also being associated with a particular central office line. All of the relays, except one in each group, disconnect the associated station set from the associated line when the relay is de-energized. One relay in each group functions in the opposite manner to connect the associated station set to the associated line upon failure of the local power supply.


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Shinoi, Tsuyoshi. (1981). Office line connection circuit during service interruptions in key (U.S. Patent No. 4260857). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4260857

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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