Patent GB-1027764-A (GB)
Title: Improvements in or relating to teletypewriters
IPC: H04L17/24
Filed: 1963-08-06
Abstract: 1,027,764. Selective printers. SIEMENS & HALSKE A.G. Aug. 6, 1963 [Aug. 7, 1962; July 5, 1963 (2)], No. 30933/63. Heading B6F. Type-wheel actions; summation type-selecting arrangements; type-carriages; power-actions.- A telex printer comprises an octagonal type cylinder 27, Fig. 1, having eight columns of characters and a pair of epicyclic multi-stage summation gear trains 15, 14 operated by setting bars 8, 9 which through draw-bars 16 adjust the sun wheels 19 of the first stages of the gear trains together with planet wheels 17 of the remaining stages of the gear trains to effect axial and rotational setting of the type cylinder to present a selected character at a printing station. The printer is operated in response to a five-code signal received from a receiver (not shown), which signal releases a cross-bar 1 setting free selected ones of five setting levers 3, which are not in end abutment with displaceable code combination elements 4 of the receiver. In accordance with the polarity of the received signals the setting levers 3 determine the direction of motion of the pair of trains comprising a two-stage epicyclic gear train 14 and a three-stage epicyclic gear train 15 by bringing either the upper setting bar 8 or lower setting bar 9 into engagement with a further cross-bar 10, which is oscillated by a cam 6 on a shaft 7 rotated by a clutch 5, which is also released by the cross-bar 1. The setting bars 8 or 9 engage stops 32 on their respective drawbars 16, Fig. 2, and displace them either to the left or right, respectively, a spring 31 on the drawbars acting as a toggle, which in conjunction with the stops 32 limits the displacement of the drawbars. The rotational typeselection is effected by the two-stage epicyclic summation gear train 14, which includes two drawbars 16 one of which acts on the first stage sun wheel 19 via a link 18 and the other on a pair of planet wheels 17 of the second stage. The last of the planet wheels is in engagement with a gear 30 fast on a shaft 29 on which the type cylinder is mounted slidably along a keyway. The rotational type-selecting is complemented by a further pair of setting bars 12, 13, Fig. 1, which are responsive to signals for the selection of either a letter or a numeral. The axial selection of a character is effected by the gear train 15 having three drawbars 16, the first of which acts on the sun wheel 19 via a second link 18, the remaining two drawbars acting on planet wheels 17, the last planet wheel co-operating with a sun wheel 20 driving a gear 21. The gear 21 is enmeshed with a sector gear 22, pivotally mounted on a shaft 23 carrying a cable pulley 25 on the end of an arm 24, so that on pivotal movement of the sector gear 22 a cable 26 attached to the carriage of the type cylinder 27 displaces the cylinder axially. In another embodiment in Fig. 2 the cross-bar 10 is of a rectangular cross-section and the ends of setting bars 8, 9 are recessed accordingly. In a further embodiment, in Fig. 3, the cross-bar 10 is replaced by upper and lower rockers 41, 42 pulling or pushing on the respective lifted or lowered setting bars 38, which replace setting bars 8, 9 and drawbars 16. The axial selection is effected by the gear train 15 through a shaft 34 having mounted slidably thereon a cage 35 with a worm 36 which engages a helical rack carried on the type cylinder carriage 33. The printer may be responsive to a six-bit binary code signal in which case a sixth setting lever 3 would replace the pair of letter or numeral setting bars 12, 13. Hammer impression arrangements.-A hammer 28 is displaced axially concomitantly with the . axial displacement of the type cylinder 27 by a cable passed around a pulley on the shaft 23. The hammer is rocked for impression by the cross-bar 10 actuated by cam 6 and the crossbar 10 and hence hammer 28 are restored by a spring 11.