Patent GB-620682-A (GB)
Title: Improvements in or relating to printing telegraph receivers
IPC: H04L17/24
Filed: 1946-04-30
Abstract: 620,682. Type-printing telegraphy. CREED & CO., Ltd., and SALMON, R. D. April 30, 1946, No. 13042. [Class 40 (iii)] A printing telegraph receiver having a type-carriage movable with respect to a stationary platen, comprises a number of setting members, one for each element of a code, with a similar number of character selector members and a similar number of function selector members with means linking the setting members to set selectively the character selector members to effect the printing of a character, and means separately linking the setting members with the function selector members which are associated with means separate from that associated with the character selector members for selecting functions to be performed. The receiver can be constructed to provide tabulation, and for printing in alphabets in which some letters have superposed accents. In the latter case the receiver, although normally providing spacing before printing, is arranged to suppress the spacing operation until the accent has been printed. The receiving arrangement comprises mechanism by which the selective settings of the receiver magnet are transferred by members 3, 4 and 5, 6 to five vertical setting bars of which 1, 2 only are shown. The selective movements of the bars are transferred to notched discs 7, 8 co-operating with radially movable rods which enter aligned notches and selectively arrest a stop arm mounted on a type-wheel shaft. The movements of the bars 1, 2 are also applied by members 23, 24 to selector members 16 mounted on shafts 11 ... 15 and formed with rollers 17 associated with selectively arranged notches 38 on function bars such as 25, 33, 34 pivoted at their lower ends and biassed inwardly by springs at their upper ends. Case shift arrangements. Function bars 25, 26, Fig. 2, corresponding to figures and letters, are mounted on pivots 35, 36 and biassed inwardly by a spring 37. When the bar 25 moves inwardly as a result of the selective setting of the members 18 ... 22, a projection 79 engages an extension 63 of a pivoted vane 60 which is rotated and latched by engagement of an extension 80 with a member 81 pivoted on the bar 26. With the vane 60 in the letters position, Figs. 2, 5, a cam 55 on the printing- cam shaft rocks a bell-crank 64 having a roller 66 in engagement with an arm of a lever 67 provided with a rod 69 extending across the full width of the printing platen 59 and engaged by the forked ends of a lever 70 which at its opposite end engages a pin 72 on the body of the type-wheel 56 formed with rows 57, 58 of type and traversed longitudinally of the platen as described in Specification 580,882. The arm carrying the roller 66 is connected by a spring 75 to a lever 74 normally latched by a pivoted lever 77 so that the movement of the arm carrying the roller is restrained. When the vane 60 is moved to the position indicated in Fig. 3 (not shown), the lever 74 is freed from the lever 77 and the arm carrying the roller 66, being no longer restrained by the spring 75, executes a longer stroke and brings the lower row 58 of characters to the printing position. The vane 60 remains in its latched position until the function bar 26 is operated to cause the extension 80 to be edged off the pivoted latch 81. Suppression of printing operation. During each rotation of a cam 99, Fig. 7, carried on a translator cam sleeve released by the selector cam-shaft, and prior to the setting of the bars 18 ... 22, a pivoted bell-crank 90, 91 restores pivoted vanes 87, 88 to a horizontal position and if the function bar 29 is operated, the vane 87 associated with the printing operation is retained in a horizontal position by a notch 93. The printing operation, i.e. the release of the printer cam-shaft, is initiated by rotation of a shaft 98 by the limited movement of a lever 97, which is prevented by the lower end of a lever 95 when its upper end is restrained by the vane 87 retained in the horizontal position. Suppression of spacing operation. This is controlled by a.function bar 27, Fig. 6, which in its operated position retains the vane 88 in its horizontal position. Spacing is normally performed by a rack 102, Fig. 8, oscillated by a cam during each rotation of a function shaft 49 and operatively associated with a pawl 101 connected to the type-wheel carriage, which is retained by a pawl engaging a fixed rack 103, as described in Specification 580,882. When the vane 88 is held in its horizontal position, a tooth 107 on a lever 106 oscillated during each rotation of the shaft 49, engages a pivoted lever 108 which raises a bar 110 to engage a pin 114 carried by the pawl 101 so that the spacing movement is not applied to the type-wheel carriage. Tabulation operation. The spacing cam is carried on a shaft having a sleeve 133, Fig. 10, connected to the shaft 49 by a ratchet clutch comprising a pivoted pawl 137 held out of engagement by a pivoted detent 139. When the end of a lever 135 falls into a recess in a cam 134 on the translator cam-shaft the arm 144 engages a projection on a lever 146 having a projection 148 which rocks the detent 139 so that the pawl 137 is released to clutch the camsleeve 133 to the shaft 49. A pivoted member 150 prevents rebound of the pawl 137 when it engages the detent 139. When tabulation is required the operation of the function bar 132 allows the lever 154 to rotate in a clockwise direction so that a hook 156 on a horizontal arm 157 engages the projection 158 on the lever 146 to prevent the detent 139 from returning to the stop position until a projection on the type-wheel carriage engages a bail 159 on the horizontal arm 157 to release the hook 156 from the projection 158 on the lever 146. Modification for printing accents on letters. A signal'designating an accent operates a function bar 172, Fig. 11, which in the position shown allows a projection on a latch 173 to retain an arm 171 integral with the arm 135 so that the lever 146 cannot actuate the detent 139 to allow the function carn-sleeve 133 to be connected to the shaft 49. After the printing operation has taken place a lever 178 actuated by cam 177 on the printing shaft allows a lever 179 to rotate under the action of a spring 181 and to rock a pivoted lever 186 to actuate the detent 139 so that the shaft 49 and cam-sleeve 133 are connected. When the lever 172 is in its normal right-hand position the latch 173 is disengaged from the arm 171 and a projection 188 latches the end 189 of an arm 190 of lever 179 so that its operation on printing a character is not effective to operate the lever 186 to effect the connection of the cam-sleeve 133 to the shaft 49. The function cam-sleeve 133 is, in this arrangement, driven at twice its normal speed, in order to allow the character spacing operation to be effected in either of the two intervals, i.e. before or after the printing of a character. The driving arrangement for the selector, translator, function and printing shafts and the relative timing of the functions performed by cams on these shafts are described in connection with Figs. 4, 12 (not shown). Specifications 392,200, 490,951, 559,466, 563,221 and 600,297 also are referred to.