655,302. Automatic exchange systems. AUTOMATIC ELECTRIC LABORATORIES, Inc. Oct. 8, 1947, No. 27064. Convention date, Oct. 9, 1946. [Class 40 (iv)] A message recorded on a loop wire recorder is transmitted to any subscriber who dials a special number, the subscriber being subsequently connected to a spool wire recorder which records a message from the subscriber in sequence with other messages similarly received. The equipment is intended for use at a local automatic exchange for registering complaints, and an operator at a main exchange may obtain access to the equipment to listen to the recorded subscribers' messages, record messages on either of the recorders, or rewind the spool recorder, by dialling an appropriate number and then transmitting an additional digit after the connection is seized. The recorded message heard by the subscribers may consist merely of instructions. Recorded message transmitted to subscriber.- When the line relay 190 operates, the drive motor 268 of a wire loop recorder 277 is started and the recording and reproducing head 269 is connected to the line conductors 274, 275 through an input transformer 254, an amplifier 276 and an output transformer 259. Relay 150 operates and completes the amplifier anode and heater circuits. Contacts 289 are closed by a driven cam 263, which maintains the motor circuit when a slow-to-operate relay 220 pulls up. A driven cam 262 closes contacts 264, applying a secondary busy earth to the subscriber's circuit conductor 280 and operating relay 200 which busies the operator's circuit conductor 281. The loop recorder is stopped after one complete revolution by the opening of cam controlled contacts 289. Contacts 264 are also opened, removing the busy earths on conductors 280, 281. Contacts 265 are closed and complete a circuit to relay 130. If the subscriber hangs up during the operation of the loop recorder the secondary earth busies the apparatus until the wire loop returns to its starting position. Subscriber records a message.-Operation of relay 130 pulls up relays 100, 120, 150 and 180. A magnetic clutch 283 is energized and disconnects the drive from a motor 250 to the rewind spool 292 of a spool recorder 278. The line conductors 274, 275 are connected to the spool recorder head 248 through an input transformer 255, the amplifier 276 and the output transformer 259. The motor is started and an oscillator 271 is connected to the recording head for erasing previously recorded messages on the wire fed from the rewind spool. If the rewind spool is empty. contact 244 is opened by a cam 242 driven from the spool and relay 130 is released. Contact 245 is also closed and connects busy tone to the subscriber's line by operating relay 170. Operator's line circuit.-Line relay 10 and slow-to-release relay 30 operate when an operator seizes conductors 285, 286, 281 by dialling an appropriate number. Relay 210 busies the subscriber's circuit conductor 280 and relay 50 operates. Operator dials additional digit.-The line relay 10 controls the drive magnet 256 of a selector switch. A slow-to-release relay 40 operates and remains closed during the dialling period and releases relay 50. Off normal contacts 241 are closed by the first movement of the switch wiper 285. Release of relay 40 at the completion of the dialling train connects earth to the switch wiper and operates a functional relay associated with the selected bank contact. Relay 40 in its released position completes a locking circuit for the operated functional relay which is independent of the selector switch circuit. Relay 50 pulls up and operates a selector release relay 60 which restores the wiper arm to its normal position and operates the relay 150 controlling the amplifier valve circuit. Relay 60 releases when the switch off-normal contacts are opened. The first contact of the switch is unconnected, and the digit 1 serves as a release digit, the holding circuit of any operated functional relay being opened by relay 40. The equipment is restored by the release of the line relay when the operator hangs up. Rewinding spool recorder.-The operator dials digit 2 and functional relay 70 pulls up, disconnecting the drive to the recording spool 293 by energizing clutch 284 and operating relays 120, 140. Relay 140 locks the operated relay 150. Motor 250 is started and the spool recording head 248 is connected to the operator's line conductors 285, 286 through the amplifier and its input and output transformers 254, 259. When the recording spool is emptied cam 251 opens contact 252 and the clutch 284 is de-energized. Cessation of the reversed recordings indicates to the operator that the wire is fully wound. Reproducing the spool recordings.-The operator dials digit 3 and functional relay 80 operates. Relays 120 and 140 operate, locking the operated relay 150. The rewinding spool clutch 283 is energized, the motor started and the spool recorder head connected through the amplifier to the operator's line. When the recording spool is fully wound cam 242 closes contacts 243, operating relay 20 which releases relay 80. Recording a message on the spool recorder.- The operator dials digit 4. Functional relay 110 pulls up, relays 100, 120 operate and operated relay 150 is locked. The rewinding spool clutch 283 is energized, the motor started and the operator's line connected through input and output transformers 255, 259 of the amplifier to the recording head together with the erasing oscillator 271. When the rewinding spool 292 is emptied, relay 20 releases the functional relay 110. Recording a message on the loop recorder.- The operator dials digit 5 and functional relay 160 operates. Relay 110 pulls up and operates relay 100 which locks relay 160. Relay 90 operates, relay 150 locks up and slow-to-release relay 130 is energized. The operator's line is connected through the input and output transformers 255, 259 of the amplifier to the loop recorder head, motor 268 is started and an oscillator 270 is connected to the recorder head for erasing the previous recorded message. Relay 230 and cam-operated contacts 289 control the stopping of the recorder after the loop has completed one rotation. Local monitoring.-A loud-speaker controlled by a switch 286 is provided.