U.S. patents available from 1976 to present.
U.S. patent applications available from 2005 to present.

Supervised single link telephone system

Patent 4081614 Issued on March 28, 1978. Estimated Expiration Date: Icon_subject March 28, 1995. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Patent References

2896021

3304376

3355555

3553385

3604854

3809824

3928732

Multi station telephone switching system
Patent #: 3991282
Issued on: 11/09/1976
Inventor: Feil

Direct station selection circuit Patent #: 4032724
Issued on: 06/28/1977
Inventor: Matheny

Inventors

Assignee

Application

No. 787608 filed on 04/14/1977

US Classes:

379/49, Central station with plural substations379/7, For detection of eavesdropping device379/142.01, RECEPTION OF CALLING INFORMATION AT SUBSTATION IN WIRELINE COMMUNICATIONS SYSTEM379/142.17, Having display unit379/159, With intercom system379/173, With call addressing379/247, With display379/265.02, Automatic call distributor (ACD) system379/373.05Directing incoming call to local appliance

Examiners

Primary: Claffy, Kathleen H.
Assistant: Brigance, Gerald L.

Attorney, Agent or Firm

International Classes

H04M 005/20
H04Q 003/64 9

Abstract

An administrative telephone system for use in schools, hospitals and the like which includes a dialable administrative telephone set and a plurality of dialless remote or "staff" telephone stations having identifying numbers, interconnected by a central exchange. The administrator can dial any staff telephone station by pressing two digit buttons on the dial pad. Associated with the administrative telephone set is a digital display device having a column of display positions. Each staff telephone station has a call-in switch. The central exchange includes storage provision coupled to the digital display for registering and displaying, in order, the numbers of the staff telephone sets which have called in and thus have indicated a desire to communicate with the administrator. By pressing the asterisk (*) pushbutton switch at the administrative telephone set, the latter is automatically connected to the staff telephone station whose number is displayed at the head of the display column, such head number being thereafter extinguished, and with the numbers in successive positions each being advanced forwardly one step in the column. The administrator can thus connect his telephone in quick succession to a series of calls stacked in the display simply by successive pressing of the pushbutton switch. Each staff telephone station has provision for sending a priority signal in addition to the regular call-in signal, under urgent or emergency conditions, and which is effective, upon receipt by the central exchange, to advance the number of the particular station overridingly to the head position in the column of the display device, the display of the number being enhanced by flashing and by an audible note to attract attention.

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