Patent GB-1045528-A (GB)
Title: Improvements in or relating to absent subscriber service equipment
IPC: H04M1/652
Filed: 1964-08-20
Abstract: 1,045,528. Sub-station equipment. NIPPON ELECTRIC CO. Ltd. Aug. 20, 1964 [Aug. 24, 1963], No. 34187/64. Heading H4K. A telephone answering and recording apparatus is connected to a telephone line by a hybrid transformer in parallel with the normal sub. set, and allows the subscriber, before he leaves his sub-station, to record a message on a recorder, using the hand-set microphone or an auxiliary microphone, monitor the message on the hand-set receiver or a loud-speaker and then leave the machine in a condition in which it will answer incoming calls with the recorded message and then record incoming messages up to the limit of the storage facility after which a voice frequency tone is transmitted to any callers announcing that the message store is full. The subscriber may telephone his sub-station and by transmitting a tone of predetermined frequency for a predetermined time the messages recorded in his absence are replayed to him over the telephone link. Alternatively, when the subscriber returns to his sub-station he may replay the messages and listen to them either over his hand-set receiver, a loud-speaker, or earphones. Figs. 1 and 2 show the answering apparatus which is connected in parallel with the subscriber's sub-set via jack JK1. The operation of the machine is controlled by switch RS (1-10) which in position 1 connects the machine to enable the subscriber to record the announcement on the tape T-ANS via either the sub-set hand-set or a microphone plugged into JK3 and the speech amplifier 4, previous recordings being erased by a D.C. signal applied to the erase head EHA. The recording cycle is initiated by operation of push-button PB1 and terminated by the conductive foil SPA on the tape loop bridging contacts SBR. By setting the function switch RS (1-10) to position 2 the subscriber may listen to the announcement replayed on his hand-set, or loud-speaker SP by operating switch KA, via the speech amplifier 4. Answering operation.-When the subscriber leaves his sub-station he sets function switch RS (1-10) to position 3. If an incoming call is received and ringing current persists for a given duration timer 6 operates to energize relay R(S) to cause the line loop to be completed and the announcement to be played back from tape loop T-ANS via amplifier 4 to the telephone line. At the end of the announcement conductive strip SPA bridges contacts SBA and causes the drive to the answering loop to be disconnected and the drive to the message recording loop T-REC to be energized. A fixed time, e.g. 30 seconds, is provided for the message to be recorded. During the setting-up period the speech amplifier input and output terminals are looped causing the amplifier to oscillate and send a tone signal to the line, the end of which indicates to the caller that the machine is ready to record his message. If the subscriber calls his sub-station he may, by emitting a predetermined frequency of predetermined duration, cause the demand frequency detector 5 to operate which causes the message loop T-REC to be wound on fast until the conductive foil SPR bridges contacts SBR when the tape speed is reduced to normal replay speed and the recorded messages are replayed over the telephone line. The speech gap at the end of the messages is detected by the amplifier 2 and switch unit 3 to revert the apparatus to be ready for further messages to be recorded. When the tape loop is full contact strip SPR bridges contacts SBR and causes the transmission of a tone indicating to further callers that their messages cannot be recorded. When the subscriber returns the messages can be replayed over loud-speaker SP by moving the function switch RS (1-10) to position 4.