Patent GB-881232-A (GB)
Title: Apparatus for transmitting stored telegraph signals
IPC: H04L17/12
Filed: 1960-08-18
Abstract: 881,232. Type printing telegraphy. TELETYPE CORPORATION. Aug. 18, 1960 [Sept. 18, 1959], No. 28637/60. Class 40(3). An apparatus for transmitting any one of a number of pre-recorded telegraph messages comprises a circular magazine which contains a plurality of cards, each perforated according to a different message. The magazine is rotatable to bring a selected card into alignment with a card-receiving device into which the card is tilted, whereupon a set of perforation-sensing pins advances step-by-step past the successive rows of code combinations of perforations in the card. The sensing pins actuate transmitter contacts which operate via a distributer to apply signals to an output line. Any other signals which are to accompany the signals stored in a selected card are transmitted in known manner by a keyboard apparatus either before or after the card. has been read. The circular magazine 21, Fig. 2, contains cards 20 mounted about an arcuate rod 32. The operator rotates the magazine until a selected card can be tilted to lie between guides 50, 51, Figs. 2, 3. The card is bent into an arc by guides 52, 53, and moves a lever 35 downwardly to release a rod 103 which is urged to the left by a spring 95 and lever 90. The rod 103 carries a plunger 104 which enters a hole 38 in the card 20 to locate the card in the correct reading position. The clockwise movement of lever 90 closes contacts 115 and this closure allows the distributer arm to rotate, Fig. 9 (not shown). As the arm rotates electro-magnet 128 is energized, permitting lever 133 and sensing pins 61 to move to the left. Those pins that are, opposite perforations in the card 20 pass through the card, and the corresponding contact pins 138 move leftwards to close their associated contact pairs 140. Each contact pair is connected to a segment on the distributer so that, as the distributer arm rotates, a series of code elements corresponding to the first row of code perforations 35 is sent over the output line, At the completion of one rotation of the distributer arm, electromagnet 128 is deenergized, the sensing pins 61 are retracted, and the carriage 58, which carries the sensing pins, steps downwards under the action of spring 165 to allow the next row of perforations to be sensed. A ratchet and pawl escapement mechanism is used to retrict the carriage to step-wise movement. As the distributer arm continues to rotate the sensing pins are moved leftwards, as before, to enter the perforations. The sensing and carriage movement is repeated until the carriage reaches its lowest position and the last row of perforations has been sensed, whereupon bracket 159 on the carriage 58 closes contacts 179 and opens contacts 118. This action stops the rotation of the distributer arm and initiates a single revolution of a cam-shaft 78. During this single revolution the various cams cause the following operations; lever 90 to move anti-clockwise to retract the locating plunger 104; the escapement ratchet and pawl to be disengaged; lever 186 (shown in broken line) to be moved clockwise to remove the card 20 from the guides and to replace it in the magazine; carriage 58 to be returned to the topmost position; and the escapement mechanism to be re-engaged. The apparatus is then ready to receive and read another card.