Supervised single link telephone system

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.