GB995571A - High speed printing system - Google Patents

Abstract

995,571. Printers. CLARY CORPORATION. Jan. 18, 1963 [Feb. 5, 1962], No. 2280/63. Heading B6F. [Also in Division G4] A printer of the type in which a web is brought into contact at selected times with a continuously rotating type-drum is characterized in that a print cycle can commence from the instant that any character on the typedrum passes the printing position. This means that when the printer is being controlled by a data processing device a print cycle commences substantially immediately a " print " signal is received without having to wait until a datum position on the type-drum reaches a reference position. As described a " print " signal on a lead 99, Fig. 7, from a data processing unit 83 passes via a gate 98 to turn on a trigger 105 thereby engaging a one-revolution clutch 53, 73. This causes a unit 87 to produce twelve clock-pulses which are applied via a lead 90, inverter 112, gate 102 and inverter 180 to a series of gates 97 which control print solenoids 30. Each of these gates 97 also receives a signal from an associated comparator 82 when the type-character in the print position agrees with the character it is desired to print, as specified by the data processing unit 83. At the end of the one revolution of the clutch 53, 73 the paper is advanced one line and two extra clock pulses are produced which reset the circuit for a further print cycle. The single revolution clutch can also be energized either by a key 116, or by the data processing unit, in order to advance the paper without any printing taking place. Type-drum.-The type-drum 14, Fig. 2, is freely mounted on bearings 15 on a shaft 17 which is eccentrically rotated in such a way that teeth 22 on the outside of the drum engage with fixed teeth 21, the arrangement being such that for each complete eccentric revolution of the shaft 17 (see also Fig. 1) a different type character is brought down above a row of printing platens 24. When a character is to be printed a solenoid is energized to raise the appropriate platen 24 at the appropriate time. Paper feed.-When a print cycle is begun a one-revolution clutch is engaged. This clutch, in addition to driving a clock-pulse producing unit also drives a cam 63, Fig. 6, which, at the end of a revolution, advances the paper via a pawl 68 and ratchet wheel 72.