Patent GB-972236-A (GB)
Title: Improvements in or relating to phototypesetting machines
IPC: B41B27/36
Filed: 1960-12-05
Abstract: 972,236. Photographic typecomposing apparatus. HARRIS-INTERTYPE CORPORATION. Dec. 5, 1960 [Dec. 4, 1959], No. 41752/60. Heading B6W. [Also in Division G4] A tabulating apparatus for use with a phototypesetting machine which includes a transducer for producing spacing movements according to the requirements of each character used in composing a line comprises a device for producing a first analogue signal related in value to the accumulated length of the line, a device for producing a second analogue signal related in value to the length between the beginning of a line and a chosen tabulating position in the line, means for comparing said signals and adapted to produce an output signal only when said second signal is greater than the first signal, and means for connecting the output of the comparing means to the machine transducer, whereby spacing movements are produced changing the value of the first signal until there is equality between the first and second signals. As shown, the tabulator is added to the machine disclosed in Specification 891,142, both the pulse generator and counting units 170, 117 of the tabulator being connected to the 1 pica stage of the line length counter 88 and the output over lead 92 via amplifier 115 to the transducer for moving the film in 1 pica steps. In use, the column or indent positions required are set by means of wandering leads 156 from each step of a switch 158 to taps on a potentiometer 155 across a 120 volts A.C. source 136, the tappings being variable such that they provide a potential of from 1 to 63 volts in 1 volt steps whereby any tab position from 1 to 63 picas along the line can be selected. The primary of a transformer 135 also is connected across the source 136 and its secondary windings aligned with relay stages 125 to 130 are arranged so that they successively provide outputs of 1, 2, 4, 8, 16 and 32 volts. As each pica is accumulated over lead 85 in the counter 88, a pulse is applied both to the film movement transducer via lead 92 and to the tabulation counter 117 whereby one or more of the relays 125 to 130 is energized. This results in a potential difference being formed between earth and lead 140 and if this is less than that between lead 160 and earth a positive output is produced in the secondary of transformer 162 which causes a triode 168 biased to cut-off to emit a pulse over lead 176 which is fed via pulse generator 170 to the line length counter, film movement transducer and tabulation counter until leads 140, 160 are at the same potential, when the machine will have been set to the chosen tab position. As shown the first position of switch 158 is of zero potential, corresponding to the left-hand margin. As the potential on lead 140 rises above that on lead 160 the negative output of transformer 162 has no effect since triode 168 is cut off, so that no pulses are generated at 170 to interfere with character and space recording, the tabulator being quiescent until the tab key 165 is again operated to step the switch 158 to cause the machine to be set to the next tab position. The tabulator may also be applied to a tapeoperated instead of a keyboard controlled phototype composing machine. Specification 768,374 and U.S.A. Specification 2,944,472 also are referred to.