Remote access for centrally located answering and recording equipment

Claim 1

Telephone answering and recording apparatus, connected by means of first and second lines to a telephone switching system including signal generating means and serving a plurality of subscriber's subsets, each of said subsets including calling signal generating means, a first one of said subsets including circuit connections directly to said first line, a second one of said subsets connected to said second line through said switching means, and said telephone answering and recording apparatus including: a recording and playback medium connectible to either said first of said second line, adapted for playback of messages to said subscriber's subsets, ringing signal detection means connected to said first line and to said playback medium operable in response to ringing signals received from said switching system; remote access means including an optical isolator including an output circuit; a full wave rectifier connected between said second line and said optical isolator; and a relay including a coil having circuit connections to said optical isolator output and a plurality of circuit contacts connected to said first and to said second lines; said rectifier operated in response to said ringing signal to convert said ringing signal to to a direct current signal and said optical isolator operated in response to said direct current signal to operate said relay to disconnect said first telephone line from said ringing signal detection means and connect said second line to said ringing signal detection means; said ringing signal detection means operated in response to ringing signals received from said switching system over said second line to initially operate said playback medium and connect said medium to said second line whereby an announcement message is transmitted over said second line through said switching system to said second subscriber subset; calling signal detection means connected to said second line in response to operation of said remote access circuit and said ringing signal detection means; and in response to a calling signal generated at said second subset, said calling signal detection means operated to further operate said medium to transmit recorded messages over said second line, through said switching system to said second subscriber subset.