The creed No. 10 tape teleprinter (recent advances in printing telegraph technique)

The recent progress in telegraphy is traced to the adoption of the teleprinter which requires no skill on the part of the operator and which is even superseding hand Morse operation, now entirely abandoned in the British service. The introduction of private wire and teleprinter exchange systems offers a further field for exploitation of this instrument. The increasing adoption of teleprinters has made it possible to modify construction by using modern manufacturing methods for quantity production. The No. 10 teleprinter is a single magnet receiving instrument driven electrically and designed to print on a paper tape by means of a type wheel and ink ribbon. Start-stop synchronism is used. The printing speed is 428 characters per minute (50 bauds), but the printer can be operated at 20% higher speed with ample margin. Perfect printing visibility is secured by locating the type wheel underneath the paper tape with the printing hammer and typewriter ribbon above and at right angles to the tape. Since the type wheel does not come into contact with the ribbon it is prevent from becoming clogged. The usual "answer back" mechanism is incorporated. The driving motor is started and stopped by the commencement and termination of signals respectively. The type wheel is positioned by an aggregate motion device consisting of a series of epicyclic chains which are operated by one element of the letter signal. Shift and subsidiary functions are arranged for. The epicyclic translator and the selector and distributor mechanisms are illustrated by line drawings and the general arrangement of the machine is explained by a series of photographs.