Patent GB-775477-A (GB)
Title: Telephone answering and recording devices
IPC: H04M1/65
Filed: 1954-03-01
Abstract: 775,477. Recording and reproducing sound. DEVENTER, H. R. VAN., and BAILEY, P. C. March 1, 1954, No. 5886/54. Class 40 (2). [Also in Group XXXIX] Apparatus for automatically answering a telephone call comprises a gramophone recorder and reproducer connectible by switches to the line and the subset. The following facilities are provided:- (1) Sending a pre-recorded message to a caller. (2) Recording a message from a caller. (3) A combination of (1) and (2) automatically controlled by timing mechanism. (4) Playing back a recording into the line. (5) Recording local speech. (6) Recording conversations over the telephone line. (7) Re-recording a message on a second record for filing purposes. Mechanical details of gramophone. Cabinet. A handset 23, Fig. 1, is mounted in a cradle comprising a pair of horn-shaped projections 24 which hold the handset securely when the lid 21a of the cabinet holding the apparatus is lifted. Overlapping turntables 25, 26 are provided, both being associated with playback arm 27 but only turntable 26 being associated with recording arm 28. Recording arm. The arm 28 is mounted on a shoe 75, Figs. 1, 2 and 7, rotated about post 76 through gearing by the motor driving the turntable 26. Arcuate movement of the arm 28 is limited by pin 87 located between stop pins 85, 86 (Fig. 8, not shown). The starting point of the talk-out message is determined by a pointed rod 95, Fig. 7, which fits into a hole 102 in the surround 29 of the turntable when knob 100 is pushed downwards. The arm 28 pivots vertically about pivots 84 and the cutter depth is determined by a screw 82 in block 83. Flange 96 prevents the arm 28 being lifted more than is necessary to clear the surround. A stud 113 projecting from the underside of the arm 28 actuates a limit switch 112 when the recording blank is filled. Reproducing arm. The reproducing arm 27 can be used with either turntable. It is mounted on a spindle 33 so that when in lower position it opens switch 37, Fig. 1. When reproducing from the upper turntable 26 the arm 27 is held up by a spring ball catch 36. On automatic operation the circuit is changed from talk-out to record when a ball 40 carried by the arm 27 operates switch 41, Fig. 3, the position of which is adjustable by a knob 44, according to the length of the pre-recorded outgoing message. Operation of a relay 52 by an incoming call lowers the arm 27 on to the record on turntable 25 by lowering a blade 48. Arm 27 has previously been set to rest against a screw 54. This screw provides adjustment of the starting point of the talk-out message. Talk-out timing mechanism. When a record is being made on the large turntable, motor 116 also drives disc 58, Figs. 9 and 10, through a magnetic clutch 204 which is operative only when switch 117 is set to " Answer." Pins 60-63 rock spring-pressed levers 64, 65 in turn to open contacts 68, 69 momentarily in turn. Switch 70 may be set to shunt none, one, or both of these contacts to pre-set the recording time to 15 sees., 30 sees., or render the timer inoperative, respectively. While a record is being made disc 58 operates a buzzer through contacts 72 to apply warning tone to the line circuit. Circuit. The driving motors 115, 116, Fig. 15, for turntables 25, 26, respectively, are controlled by relays 52, 114, respectively. The listed facilities are provided by a five-bank switch 117. The amplifier comprises a twin triode 151 and an output stage 152 to which the cutter head 77 is permanently connected. A further output is supplied to the wiper of switchbank A for connection to the line or the handset. Reproducer 154 is connected permanently to the grid of section A of the twin triode through a volume control 155, and the input circuit to section B is taken to switch banks B and E. Bank C is in the telephone circuit for isolating the transmitter and receiver for recording and playback purposes and switch bank D is for changing over the motor control arrangements. Recording the talk-out message. Recording arm 28 is taken manually over a blank on turntable 26 until rod 95 drops into hole 102. Switch 117 is then set to position 6 to disconnect the line from the output conductor 175 of the amplifier and put the transmitter 160 into series with an exciting voltage and the input transformer 156. The message is then spoken into the transmitter. At the end of the message buzzer switch 192 is pressed three times to impress a high frequency on the talk-out message as a signal to the caller to begin speaking. Testing the talk-out message. With playback arm 27 resting against stop 54 and the talk-out record on turntable 25, switch 117 is set to position 1 to energize relay 52. Relay 52 lowers arm 27 on to the record and starts motor 115. The screw 54 is adjusted so that the stylus falls into the first groove. The message is then played back. The end position of the message is adjusted by knob 44. Automatic operation. When ball 103 rings relay 52 operates to shunt the hook switch 168 and connect the L-2 side of the line to the Y side of bank 117C and so to ground, the amplifier input being now isolated from the telephone circuit. Motor 115 is energized and drives the turntable 25 so that the talk-out message is played into the amplifier and so to the L-1 side of the line. At the end of this message playback arm 27 operates switch 41 to energize relay 114, so starting motor 116. Relay 114 also connects lead L-1 to the input transformer 156 so that incoming speech is amplified by section B of tube 151 and applied to recording element 77 to cut disc 317. The timer is set to 15 or 30 sees. as previously described, after which it returns the playback arm and releases relays 52, 114 so stopping motor 116 and releasing magnetic clutch 204. Playback. Switch 117 is turned to position 2 and the arm 27 is lowered on to either the large or small record, the speech being heard in the receiver 167. With switch 117 in position 3 the record is played to the outgoing line. Re-recording. To record part of the message already on the large record a small blank is placed on top of said record and switch 117 set to position 2. The recording arm is placed on the blank and the playback arm on the relevant part of the large record. Alternative circuits. Separate amplifiers may be used for recorder and reproducer (Fig. 16, not shown) and the switch 117 is replaced by pushbuttons. A repeater coil may be used between the telephone and line (Fig. 17, not shown).