Patent GB-485636-A (GB)
Title: Automatic recording and reproduction device for telephone conversations whereby the reproduction as also the receipt can be operated from any desired telephone instrument
IPC: H04M1/65
Filed: 1936-08-14
Abstract: 485,636. Substation equipment. MULLER, W. Aug. 14, 1936, No. 22435. Void. Convention date, Aug. 15, 1935. [Class 40 (iv)] A telephone subscriber by ringing up his substation and giving appropriate tone signals can cause the reproduction of any messages that have been recorded there in his absence and, if the apparatus is of telegraphone type, can cause such messages to be erased. Recording message. After the switch 41 has been closed, the arrival of a call operates latch magnet 42 to cause power from circuit M to be switched on to the circuit shown in dotted lines. As a result, magnet 40 raises the switch-hook, the reply gramophone is driven and magnet 34 lowers the tone-arm into position. At the conclusion of the reply message, the tone-arm is raised by means not shown and a circuit is closed for magnet 38 which couples a switch-drum 83 to the gramophone drive. Studs 30 on the drum cause intermittent actuation of a buzzer S which is heard by the calling party. The drum is arranged to make only a single revolution and shortly before it comes to rest it makes a circuit over springs 22 for magnets 77, 75, 60 and 58 which have preparatory or re-setting functions and for 65 which operates a switch AI corresponding to the manually controlled switch A on apparatus 44. This causes the telegraphone tape to be driven forward and the subscriber's message to be recorded. The tape drives a cam disc 48, one revolution of which represents the tape allotted to a single message, and a cam disc 53 a complete revolution of which corresponds to the entire tape. When the cam on disc 48 reaches the position shown, circuits are made for 45 which switches off the power, and 68 which operates switch HI, which controls the same circuits as the manual stop switch H on apparatus 44, and also for 62 which releases the lever 59 and so cuts off itself and 45 and 68. Controlling reproduction from a distance. In this case, the absent subscriber, timing his actions by the buzzer signals produced by the studs 30, sends out tone signals of a characteristic frequency to actuate magnet 32 and so cause the operation of latch magnets 11 .. 13 in a pre-arranged manner which depends on the setting of manually controlled switches 5 .. 10. If he desires merely to hear the recorded messages, a circuit will now be made for 39 which cuts off 77, 75, 60 and 58, for 76, 70, 57 and 57c which have preparatory functions and for 66 which operates a switch WI corresponding to the manual key W which causes the telegraphone tape to be driven backwards. When the tape is fully wound back, the cam 99 on disc 53 moves lever 69 which is biassed to a mid-position, to the right to operate magnet 64 which controls switch AI as previously described, but in this case the recording magnet acts as a pick-up and the subscriber hears the recorded messages. In due course, the member 54 which is frictionally held to the disc 53 and the position of which marks the end of the recorded portion of the tape, moves lever 69 to the left operating 62, 45 and 68 to restore the apparatus to normal. If the subscriber wishes the messages to be erased after he has heard them, he actuates magnets 11 .. 13 in such a way that 78 is actuated initially as well as 39, 76, &c. Accordingly, when 69 is moved to the left after all the messages have been reproduced, a circuit is made for 73 which energizes 74 and feeds current to magnet 50 to erase the messages. 74 actuates a key 91 to cause the tape to be driven backwards and since lever 71 is off normal, the member 54 is held while the cam disc 53 rotates.