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:
Jan. 20, 1981
Filed:
Feb. 27, 1979
Tamura Electric Works, Ltd., Tokyo, JP;
Abstract
A control system is disclosed wherein the dialing of a specific number as the first digit is prevented. The system comprises a dial tone detector which detects a dial tone sent from a telephone exchange to a telephone set when a call is originated from the telephone set by off-hooking its handset, a dial pulse counter for sequentially counting the number of the dial pulses detected by the dial pulse detector, and circuitry responsive to signals from the dial tone detector and dial pulse counter for interrupting the loop if a number is dialed before reception of a dial tone. Additionally, when the output of the counter corresponds to the forbidden number, a talking or speech interruption control unit is operated to interrupt the talking or speech loop.