Patent GB-838990-A (GB)
Title: Telegraphic receiving apparatus
IPC: H04L17/16
Filed: 1958-03-13
Abstract: 838,990. Type-printing telegraphy. YAMURA, T. March 13, 1958 [April 7, 1957], No. 8125/58. Class 40 (3). In a printing telegraph receiving apparatus comprising a shiftable platen associated with type-bars carried in a type basket, and each having a number of characters on its typeface and in which the character to be printed is selected by code bars operatively connected to selector vanes set by the elements of a received code combination, spacing means coacting with the type basket is operated so that a full spacing movement is effected in response to predetermined signals, whilst a half of the full spacing movement is produced in response to other predetermined signals. The arrangement is utilized for a teleprinter adapted to print characters of two different languages, e.g. English and Hindu, of which the latter includes some characters requiring only half the normal letter spacing and some partial characters which can be joined with reduced spacing to certain full or complete characters to form additional characters. The arrangement described uses a 6-unit code, and has three case groups, referred to as upper, middle and lower, of which the upper group corresponds to the normal letter group. In the printing of a character of the upper or " letters " group, a full spacing movement is invariably effected, but those characters in the middle or lower-case groups requiring half spacing are indicated in Fig. 1 by semi-circular lines respectively above and below the circle denoting the key. The characters requiring half-spacing in both the middle and lower-case groups are indicated by a second concentric ring or circle. For the characters requiring half spacing in the middle and lower-case groups, the first two and last two code elements respectively are marking, whilst the characters which require half spacing in the middle and lower-case groups have the 1st, 2nd, 5th and 6th elements as marks. The character to be printed is selected by notched code bars 5 positioned by bell-cranks 3 linked to movable vanes 1 set by the elements of the code signal and the printing action is effected by a bail 21, rocked by the printing shaft 20, engaging with a notch in the undersurface of the type-selecting bar 23 which falls into aligned notches of the bars 5. The case group of the character is determined by the vertical position of the platen 45 mounted on a shaft coupled by links 46, 50, 49 to a member 48 pivoted at 42. For the upper or normal letters group, an actuator 53 is moved forward, so that the member 48 is rotated anti-clockwise and the platen is raised. For the middle case group the platen is restored to the position shown by an actuator 55L, and for the lower-case group the member 48 is rotated clockwise by the actuator 54 so that the platen is lowered, and is returned to its middle position by the actuator 55R. Two spacing function levers 6, 7 pivotally mounted on a bar 9 and biased by springs s, s are formed with notched portions associated respectively with the two lowermost and the two top selector vanes 1. The levers 6, 7 have rearward extensions each provided with a notch co-operating with a transverse arm on an L-shaped extension 16 of an arm 15 secured to the member 48. In the position shown the function lever 6 when released by the function bail can be rocked by its spring s, if the vanes set by the 1st and 2nd elements are in the marking position, whilst for the lower-case group the member 48 is moved so that the extension of the L-shaped lever is above the notch in the extension of the function lever 7 which can move clockwise when released by the function bail for those signals which have the 5th and 6th elements marking. When the platen is in the upper or normal " letters " position, the arm of the L-shaped extension 16 overlies unnotched portions of the extensions of the function levers 6, 7 which are thus held against any clockwise movement. The letter spacing movement is effected by a rack 35 secured to the type basket and engaged by a pinion 34 on a shaft 32 carrying a pinion 33 rotated by a spiral gear 31 on a sleeve connected to a shaft 18 by a clutch and four position detent member 30. For the normal or full spacing operation the anticlockwise rotation of a rod 29 actuated by the printing shafts 20 rocks a clutch-release member 27 which allows the detent member 30 to be set into rotation and which is latched by a spring-biased lever 38. An upper clutch control member 26 is biased by a spring 28 so that it is in a position to engage a tooth on the member 30, but the return movement of the printing shaft 20 rocks the member 26 clockwise so that the member 30 can continue its rotation. Before the completion of half a revolution of the disc 30 a cam 60 lifts a lever 61 engaging a lateral extension of the lever 38 unlatching the clutch release member 27 which is restored by the spring 28 and arrests the member 30 at the end of half a revolution which effects the full spacing movement of the type basket. For the half-spacing movement, the rocking of function lever 6 or 7 when selected under the action of the spring s closes contacts 14 in the circuit of an electromagnet 40 which through its armature 43 and extension 41 rocks the lever 36 to unlatch the clutch release member 27 so that the member 30 is arrested after a quarter of a revolution corresponding to the half-spacing movement. Specification 633,752 is referred to.