Patent GB-378958-A (GB)
Title: Improvements in or relating to telegraph receivers
IPC: H04L17/24
Filed: 1931-05-21
Abstract: 378,958. Type-printing telegraphy. CREED & CO., Ltd., Telegraph House, Croydon.-(Teletype Corporation ; 1400, Wrightwood Avenue, Chicago, U.S.A.) May 21, 1931, No. 15014. [Class 40 (iii).] A printer for use as a stock ticker, fire or police alarm, or the like, utilizes combined discs axially movable in accordance with the signals, and two printing hammers co-operating with two alternative rows of type on the type-wheel. The start signal tilts armature 5, Fig. 1, clockwise, pushing shaft 10 axially so that pin 26 disengages from shelf 27 and the shaft is rotated by means of friction clutch 20. During the first part of the rotation the selectors 41 are set in succession by pins such as 32, Figs. 1 and 3. If a marking signal is being received, armature 5 and shaft 10 are shifted so that the pin 32 engages its selector 41 at the surface 40, Fig. 3, and the selector after being thus depressed is held down by the latch 44. If, on the other hand, a spacing signal is being received, the armature 5 and shaft 10 are in the positions shown and pin 32 misses selector 41 but engages catch 46 so as to release selector 41 if this happens to be held thereby. The pin then engages cam surface 34 so as to tilt lever 35 about its axis 36. When once a pin 32 has engaged a selector 41 or a lever 35, as the case may be, it holds the shaft 10 against axial movement due to any change of line condition, until the selection of the element has been completed, such axial movement being prevented by the non-engaged catch or selector as the case may be. The selectors 41 set the combiner discs 58 in the manner described below. When all selectors 41 have been set, lever 124 is rocked by cam 15 so that clutch 119 becomes engaged, and printing shaft 65 makes one revolution together with type-wheel 93. This wheel has two rows 91, 92 of type co-operating with two printing hammers 85, one or other of which strikes the selected type face a resilient blow at the appropriate instant during the revolution. The hammer is selected by the last selector 41, which tilts the fork 78, 79 about the axis 80 so that the fork prongs 78, 79, Fig. 2, are in the upper or the lower position, as the case may be ; then when the feeler 71 tilts forward, one or other of two latches 73 is, by engagement at 76 or 77 with prong 78 or 79 as the case may be, disengaged from the corresponding hammer 85, which is tilted about its pivot 86 and pulled against the stop 88 so that its striking face 89 strikes the tape 90 against the passing type face with a resilient blow. Thereafter the hammer is restored by cam lever 99 and the pawl 108 effects spacing of the tape. The instant at which feeler 71 moves to bring about printing is determined by the combiner discs 58. At the beginning of the rotation of the printing shaft 65 these discs have been adjusted axially according to the setting of the corresponding selectors 41. The selectors act through extensions 51 to set the forks 52, Fig. 3, to an upward or downward position about the axis 53. Hence one of the prong ends 56 or 63 engages a corresponding cam 57 or 64 on each combiner wheel, setting it in such an axial position that it co-operates with a finger 69 or 68 as the case may be. The feeler 71 moves forward when, in the course of the rotation of shaft 65, the combiner discs present a selection of slots corresponding to those fingers 68, 69 that are operative. Printing is then effected in the manner described above. Finally clutch 119 is disengaged by arm 124 in response to the stop signal, but there is an overlap so that one letter is being printed while the next is being registered on selectors 41.