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:
Dec. 20, 1977
Filed:
Jan. 29, 1976
Otto Altenburger, Rochester, NY (US);
Stromberg-Carlson Corporation, Rochester, NY (US);
Abstract
Centralized toll restriction for private branch exchanges (PBXs) is performed by providing first and second memory addresses in the number translator of a central office switching system. The first and second addresses are matched with restricted telephone calls and unrestricted telephone calls, respectively. Those telephone lines of each PBX which are to be restricted are marked in a convenient manner, such as with tip to ground marking, while those telephone lines not restricted are left unmarked. Outgoing trunks between the PBXs and the central office switching system are temporarily marked with an unbalance upon going off-hook on a restricted telephone line, in order to transmit restriction indication to the central office switching system.