GB786037A - Improvements relating to typographical machines - Google Patents

Abstract

786,037. Typewriters. DIRKS, G.. June 23, 1950 [Oct. 1, 1948], No. 37218/54. Divided out of 786,021 [Group XIX]. Class 100(4) A typographical machine comprises means for recording. typographical matter as signals on a storage, means for recording separately corrections of the original matter, and sensing means, controlled selectively by signals in the storage, for reading the stored original matter .and the correctioms in the sequence necessary to reproduce a corrected text. As described, a printing device 1 of the type described in Specification 786,022 is movable horizontally along a slide 2 by a motor 5 and vertially on slides 4 by similar means. It is controlled by data signals from a magnetic drum 9 - one track of the drum for each line of type - and any line may be examined before printing by displaying it on a cathode-ray-tube indicator 8. The tracks bearing the original data are sensed by a pick-up head 17. Fig. 3. which is movable axially of the drum. Another head 27 senses auxiliary tracks bearing signals indicating where corrections are required, while three further heads 33, 34 and 35 are used for sensing the actual corrections or additional matter. During the rapid rotation of the drum the separate digit signals in a track are selected by an inductive distributer corriprising coils 15, 16 which move angularly, independently of the drum speed, in synchronism with the printer 1. Signals picked up by the head 17, Fig. 2, are passed by a pentode 13 when a gas tube 14 is rendered conductive by the coils 15, 16 and passed to the printing device through a coriverter of the type described in Specification 786,041 [Group XIX]. If, however, a signal is picked up by the head 27 a corresponding pulse is developed across the primary winding 28 of a further inductive distributer which, via secondary windings 29, 30 or 31, fires one of a trio of gas tubes 24, 25, 26 according to whether the signal is received in the first, second, or third phase, respectively, of rotation of the drum. Energization of an associated relay 21, 22 or 23 closes the circuit for a sensing head 33, 34 or 35 and breaks the circuit of the head 17 at contacts 18, 19 or 20 respectively. Thus the signals from the selected correction track on the drum are fed through to the printer in place of the original signals. Various modifications and alternative arrangements are suggested, including the use of step-by-step moving magnetizable tapes as described in Specification 786,034 [Group XIX] instead of the magnetic storage drum. Specifications 786,033, 786,038, and 786,039 [Group XIX] also are referred to.