Patent GB-514575-A (GB)
Title: Improvements in or relating to type printing telegraphy
IPC: H04L17/06
Filed: 1938-05-23
Abstract: 514,575. Type-printing telegraphy. OLIVETTI & CIA. SOC. ANON., ING. C., and BECCIO, G. May 23, 1938, No. 15358, [Class 40 (iii)] A printing telegraph transmitter of the start-stop type has individual keys for each letter or symbol, means for automatically sending a case-shift signal when changing to a case other than that of the preceding character, and means for storing each combination while the succeeding one is being set up by the keyboard. Transmitting and storage mechanism.-Under the key levers 3, Fig. 1, and mounted on the same supports 5 as the code bars 2, is a member 7 which on the depression of any key is moved to the left against the action of a spring 8. The movement is communicated through a lever 10 pivoted at 11 to a detent 13 which, engaging a projection 15, moves to the right a lever 16 integral with a detent 18. This releases a stud 19 carried on the transmitting cam shaft 20 allowing it to make one revolution. If a key is held depressed for a time longer than that of one revolution a cam 22 raises the detent 13 out of the path of the projection 15 so that not more than one revolution can be made. At the commencement of the revolution a cam 24 moves a lever 26 clockwise which through link 28 and a lever 29 raises a bail 31 common to five members 33 each individual to one of the five code bars 2. The rising movement is communicated through individual springs 32 to the members 33 so that a tooth 34 of each comes on one side or other of a similar tooth 4 on the corresponding code bar according to the position in which it has been set, Figs. 2 and 3 (not shown). After the passage of the lobe on the cam 24 the projection 31 again descends and holds the members 33 in the position in which they have been set by engaging with teeth 35 while the code bars are made free to take up a new position. The movement of the members 33 to one side or the other is used to set slidable members 40 accordingly by means of beams 37 pivoted at 38. The sliding members 40 are designed to hold or release pivoted members 43 actuating the contact actuating member 51, when the members 43 tend to rise by the configuration of the transmitting cams 47. Automatic case shift.-Carried parallel to the code bars and actuated with them is a bar 54, Fig. 4, whose teeth are so shaped that it is moved to the left by any symbols key and to the right by any letters key. In Fig. 4 the parts are in position for the transmission of letters. If now a symbols key is depressed the bar 54 moves to the left as in Fig. 5 (not shown) tilting a three-armed lever 59, 61, 65 clockwise, the arm 61 of which moves a bell crank 63 to bring a projection 110 carried by it over the five slidable members 40 to prevent upward movement thereof. The arm 65 produces anticlockwise movement in a frame member 66 pivoted at 67 on one arm 73 of a three-armed member pivoted at 74. By links 69, four arms 68 of the member 66 insert or withdraw pins 49 between depending lugs 70, 71 of two associated parts, Figs. 7 and 8, of the four outside transmitting levers 43. The central lever 43 is formed in one piece with a depending projection 53, Fig. 6. The anticlockwise movement of the frame 66 withdraws the four pins 49 and presents a detent 72 to hold the projection 53. The members 43 cannot now be influenced by the slidable members 40 and the transmitting cams 47 consequently send impulses corresponding to the two first and last levers 43 being free while the centre one is held. The signal sent represents the corresponding case shift signal. This is passed to the local receiver wherein it effects change of case. The resultant mechanical movement is communicated through a link 80 to the arm 76 of the three-armed lever 73, 75, 76 producing in it an anticlockwise rotation, a movement which raises the detent 72 and reinserts the pins 49 between the component parts of the levers 43 which thereupon act as a unit. The movement also, through suitable mechanism, Fig. 12 (not shown) raises the detent on the transmitting cam shaft, allowing it to make a further revolution during which the combination set up in the slidable members 40 is transmitted, a projection 111 carried by a pivoted lever 78 connected to the third arm 75 of the three-armed lever 73, 75, 76 being moved to a position wherein it prevents any rise of the slidable members 40. In a similar manner when a letters key is depressed after a symbols key the camshaft again makes two revolutions during the first of which a signal representing the appropriate change is sent and during the second of which the actual character is transmitted. In order to avoid the loss of time involved by the setting of the local printing mechanism in response to the transmitted shift signal, two selectable. members may operate directly with the selector code bars so that one or other is selected when the code bars are set in response to a shift signal and, according to which is selected, the movement effects the tilting of a member, corresponding to the three armed lever 73,75,76, clockwise or anticlockwise. Answer back.-If an answer back device is fitted the cam drum for the purpose will operate projections 86 on the transmitting levers 43 to send the desired signal. A shift signal preceding the call will condition the transmitter for the sending of symbols and through the link 80 will move the three-armed lever 73, 76, Fig. 14, accordingly. It is therefore necessary that the bar 54 should be moved to the corresponding position and this is effected by means of a connected link 97 and a lever 98 pivoted at 99 and carrying a stud 100. If the stud 100 is lowered it rides against an inclined face of a tooth 89 carried on the bar 54 so moving it to the left. In rising from that position the stud 100 rides against the surface of a similar tooth 90 and moves the bar to the right.