Patent GB-886530-A (GB)
Title: Apparatus for the automatic adjustment of printing forms and control of tabulation for interconnected teleprinters
IPC: H04L13/18
Filed: 1958-03-21
Abstract: 886,530. Typewriters. CREED & CO. Ltd. March 21, 1958 [March 22, 1957], No. 9116/58. Class 100(4) [Also in Group XL(b)] In a teleprinter system, apparatus for establishing vertical and horizontal alignment of a message form on the called teleprinter with a message form on the calling teleprinter comprises a line-feed mechanism and a spacing mechanism incorporated in each teleprinter and operative respectively to effect line-feeding and spacing movements of the message form thereon, means for detecting when a message form on the calling teleprinter is in an initial position, a counter incorporated in each teleprinter for counting up to a predetermined number of linefeed combinations transmitted by the calling teleprinter, means for engaging each said counter for operation on establishment of a connection between the teleprinters, means operative as a result of detection of the message form in the said initial position for immobilising the linefeeding mechanism of the calling teleprinter whilst permitting line-feed signal combinations to be transmitted to the called teleprinter, means included in both said teleprinters operative to effect a counting step each time a line-feed combination is transmitted by the calling teleprinter, means for detecting when the message form at the called teleprinter has been fed lineby-line into vertical alignment with the message form at the calling teleprinter, means operative as a result of the detection of said alignment between the message forms for immobilising the line-feeding mechanism of the called teleprinter whilst permitting the stepping of the counters of both said teleprinters to continue, means operative as a result of both said counters having counted up to a said predetermined number of signal combinations to cause said counters to reset to a zero position, means incorporated in each said teleprinter and operative at the calling teleprinter for terminating the transmission of line-feed signal combinations by immobilising a depressed key thereat in its action of maintaining a connection between a transmitter driving shaft and a cam sleeve of the calling teleprinter, and means incorporated in both said teleprinters and operative at the calling one of said teleprinters for establishing horizontal alignment of both said message forms when the carriages of said teleprinters have reached a predetermined position during tabulating movements thereof. Initially at the calling teleprinter, when the message sheet 7<SP>1</SP>, Fig. 4, has been fed over a plate P to the correct printing position of a form portion of the sheet a plunger 56 rises through a hole 2<SP>1</SP> in the form 7<SP>1</SP> to operate a switch member 49 to close contacts g, h and also contacts in the circuit of an indicating lamp. The operation of the "who are you" key by the operator at the calling teleprinter rocks a lever 42 which through a pivoted three-armed lever 41 actuates a detent member 39 to allow a pivoted cam-follower member 40 to disengage from a cam track on a sleeve 43B which through a spring 44A is engaged with a sleeve 43C on a driving shaft 45 which is disconnected by the member 40 after transmission of the request signal. At the called teleprinter the reception of the request signal operates a lever 1, Fig. 2, which through an arm 2 rocks a plate so that a tooth 18 raises a lever 13 to actuate a member 19 to close contacts a, b of a switch 81 to energize a magnet M1. The lever 13 has a projection 14 engaging a pin 46 on a ratchet wheel 27 secured to a cam plate 24 connected to shaft 11 by a coil spring 25 and engaging a cam plate 24 having a recess engaged by a projection 22A on a lever 22 which is raised and actuates a pin 20 to close contacts c, d of a switch 51. The operation of the answer-back mechanism rocks a lever 47 carrying a pivoted bell crank 36, and in conjunction with the energization of magnet M1, a projecting part 36B rocks the detent 39 to allow the cam sleeve 44 to be coupled to the shaft 45 to transmit the identification signals of the called teleprinter. On reception of these signals the transmitter operator operates the bar 1 to set the counter at the initial position, and with contacts g, h already closed, and contacts c, d now closed, a magnet M2 is operated to suppress the normal line-feed operations effected by a line-feed bar and intervening mechanism transmitting the movement through an arm 52 and bell-crank 51 to a pawl 50 engaging a ratchet 74 on the shaft of the printing platen 58. To establish vertical alignment of the form portion of the sheet 7<SP>1</SP> at the called teleprinter the line-feed key at the calling teleprinter is operated in conjunction with the repeat key 35 to transmit a succession of line-feed signals. For each line-feed signal transmitted the bar 7 is moved to the left and then to the right and through arm 6 oscillates a pawl 5 which stops the ratchet wheel 27 and tensions the spring 25, with similar stepping and operation at the called teleprinter, but with the feeding of the message sheet 7<SP>1</SP> until the contacts g, h are closed, indicating that the form portion of the sheet 7<SP>1</SP> is in the correct printing position, and also operating magnet M2 to suppress further line-feeding action. Line-feed signals are still sent with consequent stepping of the ratchet wheel 27 and cam plate 24 at both teleprinters until the pin 46 at each teleprinter rocks the associated arm 13 to close contacts a, b energizing the magnet Ml which allows the member 40 to disconnect the sleeve from the shaft 45, and also permits the tooth 18 to pass to the dotted line position in which the bar 1 is restored to the normal right hand position and a detent member 9 is rocked so that the retaining pawl 8 is lifted and the ratchet 27 is returned to its normal position under the action of the spring 25. The cam plate 24 is also returned to its normal position in which the contacts c, d are opened to de-energize the magnet M2. The horizontal, or tabulating position is determined by tabulating stops 60A adjustably positioned on a rail member 62A disposed in a pivoted frame lying parallel to the spacing traverse of the printing carriage 66C which carries a pivoted actuating member 66A. The tabulating operation is effected by actuation of the space key followed by operation of the repeat key 35, and spacing movement continues until the pivoted member 66A, by engagement with a stop member 60A, rocks an arm 63A carrying a member 65B Operating a switch 65A to close contacts e, f which energize Ml, operating to eliminate the effect of the repeat key in connecting the cam sleeve 44 to the driving shaft 45. For different tabulating positions on various lines, a number of stops 60A may be employed, with appropriate re-operation of the space and repeat keys as required.