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. 02, 1985

Filed:

Feb. 28, 1983
Applicant:
Inventors:

William A Burger, Eatontown, NJ (US);

David M Embree, Reading, PA (US);

Martin H Singer, Fair Haven, NJ (US);

David R Vogelpohl, Indianapolis, IN (US);

Assignees:

AT&T Information Systems Inc., Homdel, NJ (US);

Bell Telephone Laboratories, Inc., Murray Hill, NJ (US);

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

In the disclosed coded telephone ringing signal method and circuitry, audibly distinguishable ringing codes are generated by alternately shifting between at least a pair of single frequency tones at different modulation rates. Other distinguishable ringing codes are generated by changing both the modulation rates and tone frequencies utilized.


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