Patent GB-1059918-A (GB)
Title: Improvements in or relating to teleprinters or like mechanisms
Inventor: WATERMAN HERBERT CHARLES
IPC: B41J2/425
Filed: 1963-11-14
Abstract: 1,059,918. Selective printers; selective electric signalling; web feeding. MOTOROLA Inc. Nov. 14, 1963, No. 45057/63. Headings B6B and B6F. [Also in Divisions F2 and G4] Wire print head carriages; electrical input arrangements; selective electrical signalling.- A teleprinter 10, Fig. 1, for recording information on a recording web 16, in accordance with binary code signals, comprises an electrode assembly including movable electrode units 37, 38, 39, Fig. 2, positioned at one free side of said web and a stationary electrode 22 positioned on the other free side of said web, said movable electrode units being repeatedly moved by a motor-driven belt 33 passing around puleys 31, 32, in a linear path across the said sheet in a direction transverse to the direction of movement of the sheet and circuit means coupled to said electrode assembly for applying said binary coded signals thereto to produce marks on the web in the form of characters, such that a complete line of characters is formed each time one of the movable electrode units scans across the recording web. Each of the movable electrode units comprises a plurality of printing wires 42, Fig. 6, extending through an electrode body 44 in alignment and contact with conductors 43 in grooves of an insulated panel 36 on one side of the body 44 and in contact with the recording web 16 on the other side. The ends of the wires 42, Fig. 2, are slightly offset so that when the printing pulses are applied to each wire from top to bottom in uniform time sequence the canted wires compensate the scanning velocity to produce a vertical column of printed dots. Similarly the belt 33 is disposed at an angle to compensate the web feed and produce a horizontally printed line. The printing information derived from radio signals which may be transmitted as frequency, amplitude or phase modulations of a carrier signal and comprises a plurality of code groups, five print code groups, one for each column, representing the characters and at least two blank code groups preceding the print code groups from which a line start signal is derived. Each code group for each column of a character comprises seven pulse intervals, the first two containing synchronizing information and the following five, one for each print wire, containing the printing information. The printing signal is supplied to an input unit 85, Fig. 10, and passed to a trigger circuit 86, which shapes the signals to produce a voltage waveform 100 (Fig. 11, not shown) having a binary " 1 " and " 0 " levels. The output from the trigger unit is fed to a bi-stable circuit 87, whose actuation starts a clock circuit 88 which generates pulses at the same rate as the pulse intervals of the printing signal. The pulses from the clock circuit are supplied to a ring counter 89 having seven stages 101 . . . 107, to actuate each stage successively, the last stage resetting the bistable circuit 87 and stops the clock circuit 88. As each of these counter stages 102. . . 106 is actuated by the clock pulses an output is supplied to a corresponding one of the AND gates 121-125 connected to a respective one of the print wires 42 and supplies an electrical potential to produce a dot on the record sheet 16 when a coincident binary " 1 " signal has also been received from the trigger circuit 86. After several repetitions of this cycle, in response to succeeding blank code groups, an integrating circuit in the line start control section 131 is charged to a reference level and a line start latch 41, Fig. 1, is released to permit a subsequent electrode unit, such as 38 now at the left-hand margin of the recording web, to start its scan. In another embodiment (Figs. 13, 14, not shown) the electrode 22 may be replaced by a sandwiched multi-element structure comprising parallel conductive strips arranged to extend across the width of the record web 16 and the gates 121 . . . 125 are replaced by the scanning heads 113 (Fig. 16, not shown) co-operating with the conductive strips through the medium of the recording web of a uniform volume resistivity type. Margin and carriage stops.-The movable electrode units 37, 38, 39, Fig. 1, which are driven by a continuously rotating motor 51, through a friction clutch assembly (Fig. 9, not shown) mounted on a shaft 54 are arrested at the left-hand margin of the record web 16, by a line start latch 41 to provide a uniform margin. The line start latch 41 comprises a solenoid 91 which when actuated by a line start control section 131, Fig. 10, on receipt of a signal, attracts its armature 92 which disengages a tip portion 93 abutting a projection 47, Fig. 6, on the body 44 of the electrode units. Web feeding, registering and guiding arrangements.-The recording web 16 is continuously advanced by a drive roller 66, Fig. 5, cooperating with an idle roller 19 and the sheet is guided by rollers 20, 18 and supported at the printing station by a plate 22, Fig. 3, forming also a stationary electrode. The web is drawn off a roll mounted on a grooved shaft 17, supported rotatably in slots 14 of a frame 13. The driving roller 66 of a tubular structure is attached at one end to a sleeve of a crown wheel 64, Fig. 1, mounted on a shaft 71, which also passes through the driving roller 66 and has at one end an arm 72 co-operating with a pin 73 on the crown wheel 64. The arm 72 has also a pin 74 to which there is attached a spring 76, Fig. 2. The shaft 71 has two grooves 81 and fitting into each of which there is a small ball 82, which is seated in a corresponding opening provided in the tubular roller 66. A pair of cam projections 84 extend from the shaft 71 in alignment with the balls 82. In operation to align the recording web 16 which may be misaligned the pin 73 drives the shaft 71 at the same speed as the tubular roller 66, but when the arm 72, Fig. 3, passes the upper position the spring 74 pulls the arm 72 down rapidly whereby the projections 84 will contact the balls 82 against the roller 19 to separate the rollers 19 and 66 slightly. The recording web is released momentarily to permit springs 78, 79 to re-align the web if it has deviated from its aligned position.