Patent GB-740170-A (GB)
Title: Improvements relating to statistical data recording apparatus
Inventor: FORMBY JOHN ALBERT
IPC: G06F7/24
Filed: 1952-06-20
Abstract: 740,170. Statistical apparatus; digital electric calculating apparatus. FORMBY & CO., Ltd., J. Sept. 21, 1953 [June 20, 1952], No. 16598/53. Divided out of 740,156. Class 106 (1). A keyboard operated magnetic recording apparatus having a helical magnetic track is characterized in that a set of data representing keys is associated with a set of unique magnetic patterns derived selectively from one or more rotary electromechanical generators of the electrostatic type, each having a rotary member and a stator plate on which the desired waveforms are engraved in an annular zone, the rotary member being arranged to move in correlation with the magnetic track irrespective of speed each time a key is depressed so that the data representing electrical signals derived from the electrostatic generators cause a magnetic pattern of substantially the same waveform to be recorded on the track. Fig. 1 shows pairs of contacts 1 associated with the keys of a typewriter arranged in ten groups of four representing the symbols Oaku, 1blv, 2cmw, 3dnx, 4edy 5fpz, 6gq/, 7hr" 8is., 9jt-, and an eleventh group representing all other keys together with the space-bar. Each group is associated with a gasfilled valve 2, one contact of each pair being at earth potential, while the other is connected via a potentiometer 3 to a negative biasing potential provided by a potentiometer 4, the centre portion of a potentiometer 3 being connected to the control grid of the valve. The cathode of each valve 2 is held at a negative potential by means of the potentiometer 4. When one of the keys is depressed a positive potential is applied to the grid of the associated valve sufficient to cause it to strike. The anode load of each valve is connected to a potentiometer 5, one end of which is earthed, the other connected to the anode and the variable point to one of the separate zones of a stator plate 6. Thus when the valve strikes it causes a negative polarizing voltage to be applied to the associate zone of the stator plate. Similarly a second set of contacts 7 associated with the keys are divided into three groups abcdefghij, klmnopqrst, uvwxyz/,.-, each associated with a similar valve 8 by means of a potentiometer 9, the valves having potentiometers 10 as anode loads, the variable points being connected each to one of three zones of a second stator plate 11. Thus when a numerical key is depressed a polarizing potential is applied to the appropriate zone of the stator 6 only, but when one of the keys associated with the valves 8 is depressed a polarizing potential is applied to one of the zones of stator 11. When any other key is depressed including the space-bar a potential is applied to the eleventh zone of the stator 6 which is associated with the " null " symbol. Fig. 2 shows a gas-filled valve 12 which is arranged to strike when any key is depressed, energizing a solenoid operating coil 13 which is connected in the anode circuit. A further gasfilled valve 16 acts as quencher. The action of solenoid 23 (coil 13) causes a cam 22a to rotate, opening contacts 22 and later closing them, causing the valve 16 to strike thereby causing all the conducting valves 2, 8, 12 to be extinguished and the solenoid to be de-energized. Fig. 3 shows the action of solenoid 23 which is adapted to strike a lever 26 and toothed sector 29 engaging a toothed wheel 30 integral with a ratchet-wheel 31 so as to drive a spur-wheel 33 in a clockwise direction. Fig. 4 shows the other end of shaft 35 carrying the cam 22a and associated contacts 22, and a spring-loaded detent device 38a, 38b which positions the shaft exactly after one complete rotation. Mounted on shaft 35 is also a worm 41 which engages a worm-wheel 42 which is mounted on one shaft of a differential mechanism 43. The other shaft of the differential mechanism carries a spurwheel 45 engaging a pinion 46 on the shaft of a Selsyn motor 47. When the shaft 35 makes one complete rotation the shaft 51 turns through on hundred and twenty-eighth part of a revolution, carrying the drum with it. Each stator plate 6 and 11, Fig. 5, is associated with a corresponding rotor 56 and 57, a second pair of rotors 59, 60 are associated with a pair of stator plates 61 and 62, there are also four collector plates 58 insulated by fibre spacers 64. Fig. 7 shows the arrangement, for amplifying the signals obtained from the electrostatic units and modulating waveforms of the first set by those of the second. The collector plate 58 of the first electrostatic unit is connected to the control grid of a cathode follower valve 78 the output being amplified by the valve 79. In the case of the second electrostatic unit the output from the collector plate is fed direct to the grid of an amplifier valve 80, the output of which is applied to the suppressor grid of a valve 81. The modulated output of valve 81 is applied to the recording-head 70.