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:
Feb. 18, 1992

Filed:

Apr. 09, 1991
Applicant:
Inventors:

Ryuichi Nakajima, Tokyo, JP;

Koji Yamana, Tokyo, JP;

Assignee:

Tandy Corporation, Fort Worth, TX (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379 98 ; 379160 ; 379159 ; 379172 ; 370 30 ;
Abstract

An improved telephone system in which a plurality of telephone units connected to a common telephone line is directly connected to an outside telephone line. Each telephone unit contains complete capability for making outside calls, for making extension calls, and for the automatic exchange control of the use of the common telephone line. This telephone system provides functions, including making multiple simultaneous calls on a single telephone line without requiring separate exchange equipment, additional extension or signal lines, or any sacrifice in signal quality. Furthermore, the telephone units in this system can be connected to more than one outside telephone line to expand the system capacity.


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