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:
Jun. 12, 1979
Filed:
Aug. 25, 1977
Richard J Ullakko, Kirkland, WA (US);
Victor M De Pinto, Bellevue, WA (US);
Tone Commander Systems, Inc., Redmond, WA (US);
Abstract
The system receives subscriber station address information in the form of frequency coded tone signals transmitted from a calling station along a common intercom circuit, and selectively accesses a called subscriber station having a corresponding station address in order to produce a call indication ring-out thereat. The system is comprised of decoder circuitry including a digital multi-frequency tone detector for receiving and decoding station address information transmitted from a calling station, and access circuitry operatively associated with the tone detector for routing an appropriate call indication signal to the called station. Signals which appear at the output of the tone detector are delivered to the access circuitry which, in turn, initiates the call indication sequence and routes additional signals back to the tone detector for controlling it during call indication. The system is suitable for use with 10, 19, 36 or varying numbers of subscriber stations and may include, for applications having more than 10 subscriber stations, appropriate transfer and associated output control circuitry for double digit operation.