Patent GB-559558-A (GB)
Title: Improvements in or relating to telegraph apparatus
IPC: H04L15/12
Filed: 1942-08-21
Abstract: 559,558. Code telegraphy. CREED & CO., Ltd., THOMPSON, A. E., and SALMON, R. D. Aug. 21, 1942, No. 11824. [Class 40 (iii)] A keyboard - operated Morse transmitter comprises combination bar mechanism for analysing the Morse signals into dot, dash, and space elements and separate camoperated means for transmitting these elements in correct sequence. As the number of elements representing a character varies, it is arranged that following the transmission of the space after each character, the mechanism is returned rapidly to normal condition to unlock the keyboard so that the operator can depress the keys more rapidly when transmitting a series of characters represented by a small number of elements than when transmitting characters represented by a larger number of elements. Short characters such as E, and space may control separate mechanism so arranged that either of these keys may be operated while the main mechanism is transmitting, the signal being stored until the main mechanism has finished transmitting. The keys, such as 6, Fig. 1, control six combination bars, such as 1f, so mounted and cut that the associated link 5f, say, can be moved to the right or left or remain in a middle position. Each key, when depressed, also engages a trip bar 7 to move a link 10, thereby operating a detent 19 to release a cam distributer shaft 22 which is rotated step by step. Each of the links, such as 5f, has an extension 38 engaging a sliding member, such as 39f, one only being fully shown in Fig. 2. The sliding members 39a ... 39f are raised in turn by cams 42a ... 42f on the shaft 22, and are formed with projections such as 44. adapted to engage one or other of three bail members 45, 46, 47, according to whether the link, e.g. 5f, and sliding member. e.g. 39f, is moved to the left or right or occupies a middle position. The bail members 45, 46, 47 have extensions, such as 48, adapted to release sleeves 50, 60, 70 when the corresponding bail is raised. The sleeves 50, 60, 70 are driven by friction clutches from shaft 51, sleeve 50, when rotated, closing contact 66 to send a dot, and sleeve 60 closing the same contact for a longer time to send a dash. Sleeves. 50, 60, acting on shaft 15, control the step-by-step rotation of the cam distributer shaft 22, but sleeve 70, after a partial rotation corresponding to the time of a space, is arrested with its cam 71 in a position to hold the detent 19 in an inoperative position, so that the shaft 22 returns quickly to its normal position after the transmission of a space, irrespective of the number of dots or dashes previously sent by sleeves 50, 60. While the shaft 22 is out of its normal position, cams 30a, 30b position a frame 31 to engage members, such as 33, on each link, such as 5f, to lock the combination bars in their operated position until the shaft 22 returns to normal. In the modification in which certain keys, corresponding to the shortest signals, control separate mechanism, Figs. 3 and 4 (not shown), these keys release additional sleeves on the shaft 51, the sleeves being controlled by an additional cam on shaft 22 (when this is out of its normal position) so as to store the short signal until the transmission of a signal controlled by the combination bars is completed. During the transmission of the short signal the combination bars are locked. The transmitter may be combined with a Morse recorder driven from the same motor, the send-receive switch being linked to shaft 87 carrying roller 88 which controls the feed of the tape 89. An extension 82 of the armature of the receiving magnet 80 presses the tape against roller 83 inked by engagement with a roller 87 dipping into a bath of ink.