Patent GB-308608-A (GB)
Title: Improvements in or relating to the recording of telegraphic or like signals
IPC: H04L17/24
Filed: 1929-03-22
Abstract: 308,608. Siemens & Halske Akt.- Ges. March 24, 1928, [Convention date]. Void [Published under Sect. 91 of the Acts]. Type-printing telegraphs. - In a type-printing telegraph a particular combination of impulses effects different sets of operations according as it is received once, twice, or three times in succession. In the example described, the combination when sent once effects the linespacing operation in a page-printing telegraph; when sent twice it effects line-spacing and also closes the circuit of a strip-perforating receiver: and when sent three times it effects line-spacing and also disconnects the perforator. The selector bars 1, Fig. 1 (elevation), when set by the appropriate combination permit the selector rod 3 to move to the left, pushing a catch 23, formed on a lever 10, into the path of the printing hammer 6. As the printing hammer rises, the lever 7 is rocked about its pivot 8, and the linespacing mechanism is released by the rod 22 which is moved by the bell-crank 20 and link 19. At the same time the pawl 44, carried by the rod 22, moves the rack 45 one step to the left, while the pawl 51 carried by the rack 45 moves the rack 52 one step to the left, holding pawls 46, 53, being also provided for these racks. The rack 52 by means of a bell-crank 62, Fig. 4 (plan), moves the plate 37 so as to bring a depending rod 36, which passes through a hole 36a in it, into the path. Fig. 7, of a tappet 38 which moves upwards with the printing hammer 6. If the appropriate signal is received only once, the hammer 6 misses the catch 23 when rising in response to the next succeeding signal. The arm 7 therefore remains in the position shown in Fig. 1, and the rod 36 is caught by the tappet 38, raising the bar 25 and rocking the lever 33 so that the projection 34 depresses a spring 67 to effect the release of the racks 45, 52; the spring 67 by means of a downward projection 56, which it carries, disengages the pawls 53, 51, releasing the rack 52, and at the same time by means of the plate 69 depresses its companion spring 68 which similarly disengages the pawls 44, 46, releasing the rack 45. The apparatus therefore resumes the position shown in Fig. 1, and only line-spacing has been effected through the rod 22. If, on the other hand, the bar 3 is selected by two successive signals, the second signal connects up the strip-perforating receiver by closing the contacts 60, Fig. 4, in the following manner. Since the bar 7 is rocked about its pivot 8 by the second signal, the projection 34 remains stationary owing to the parallelogram-construction of the linkwork 7, 19, 33, 25, and, further, the rod 36 moves upward with the arm 7 so that it is not engaged by the tappet 38; the racks 45, 52 are therefore not released, but are moved leftwards, Fig. 1, a second step, so that the cam 57 on the rack 52, Fig. 4, closes the perforator contacts 60; at the same time the rod 36<1>, Fig. 7, is moved into the path of the tappet 38. When, therefore, the tappet rises on receipt of the next signal, it raises the rod 36' and bar 25<1>, Fig. 7, tilting a lever behind and similar to the lever 33, Fig. 1, and thus depressing the spring 68 so as to release the rack 45, while the rack 52 is retained by the holding-pawl 53. The bar 25' is held up by engagement of the pin 24<1> with a recess 27, so that as long as ordinary printing signals are being received the rod 83<1> is raised free of the tappet 38. When, on the other hand, with the apparatus in this situation a single linespacing signal is received, the lever 7 is raised and a projection 74 on the bar 25<1> strikes an abutment 73 which releases the engagement recess 27 and pin 24'; at the same time the rod 22, while effecting line-spacing, moves the rack 45 one step to the left, but the rack 52 is not affected since the pawl 51 now works upon the smooth part of the rack. At the next upward stroke of the tappet 38 the rod 36<1> is pressed upwards and the pin 24<1> re-engages in the recess 27 of the bar 25<1>. If now the selector bar 3 is selected by three successive signals, the first signal releases the bar 25' as just described and moves the rack 44 one step to the left. The second signal does not, however, release the rack, since the arm 7 in rising raises the parts out of reach of the tappet 38; meanwhile the rack 44 moves another step and the pawl 51 engages the teeth on the rack 52. The third signal moves both racks one more step to the left, the guide plate 37 being also moved a further step by the rack 52, Fig. 4. Both rods 36, 36<1> are now out of the path of the tappet 38, but the lever 42, pivoted at 41, has been moved by the plate 37 into this path, so that the tappet in descending depresses the lever 42 and thus, through the rod 71, depresses both springs 67, 68, so that the racks 45, 52 are released and return to their normal positions, the perforator contacts 60 being thus disconnected.