Patent GB-671759-A (GB)
Title: Improvements in or relating to keyboard controlled telegraph apparatus
Inventor: SALMON REGINALD DENNIS
IPC: H04L13/08
Filed: 1950-04-12
Abstract: 671,759. Type-printing telegraphy. CREED & CO., Ltd. April 12, 1950, No. 9013/50 Class 40 (iii). In a keyboard-controlled telegraph trans. mitter comprising codebars which are selectively controlled by key-levers in accordance with the code combination of a signal, the settings of the code bars being transferred to rows of pins on a rotatable storage device carrying reading-off members and rotatable with the storage device as the code combinations are transferred thereto and rotatable in the opposite direction to allow the settings of the pins to be transferred to the reading-off members, the settings of the code bars are transferred to a first set of storage members whose settings are transferred en bloc to the storage pins and the settings of the reading-off members are also utilized to control simultaneously a final set of storage members which in turn control the code combination transmitted. The movements of the sensing device in the first direction with the storage device and in the opposite direction to read off the settings of the pins are both effected by a driving motor preferably utilizing two differential gear assemblies. Keyboard control of storage device. The depression of a character key lever 1 selectively operates the code bars 9, of which one only is shown, and a universal bar 2 which moves a stepped detent lever 4 slidable on a block 5. The step 7 engages a lever 8 having a depending portion normally contacting a stop 44 which is rotated to rock a latch 15 releasing a lever 17 which has a locking projection 11 associated with projections 10 on the code bars 9 and an end portion which lifts a lever 19 so that a pivoted pawl is released to clutch a cam sleeve 25 to a driving-shaft. A cam 41 on the sleeve 25 engages a pivoted bell-crank 42 to rotate the lever 17 to unlock the keyboard and to disengage the pawl 23. The release of the operated key lever allows the universal bar 2 to return to the left and to free the lever 8 so that the stepped lever 15 can latch the lever 17. A cam 43 engaging the end of the lever 4 also releases the lever 8 in case the key lever has not been released soon after the cam 41 operates the lever 17. The code-bars 9 carry projections 34, 35 associated with T-levers 33 pivoted on a shaft 95<SP>1</SP> in a frame 30 operated by a reading cam 28 on the sleeve 25. The T-members have stems engaged in grooves in storage members 36 which are selectively rocked against steps 58, 59 and a cam 50 rocks the members 36 to engage or miss pin-operating members 39 pivoted at 51. The members 39 which are rocked about the pivot 51 depress pins 52 arranged axially in groups of five on a cylindrical storage drum 49. The pins 52 are reset by a member 54 operated twice by a cam 95 during a single revolution of the shaft 25. The drum 49 is carried on a shaft 106 connected by a friction clutch 182, Fig. 3, to a constantlyrotating gear-wheel 181 and is released to rotate through a distance corresponding to one tooth of a ratchet-wheel 61 by a pawl 60 biased by a spring 62. Automatic insertion of case shift signals. The transmitter arrangement is such that the depression of a key lever effects the insertion of the appropriate case-shift signal, if a character is in a case different from that of the preceding character. The operation of a character key lever in the letter case-for example, the key 197-causes the bar 191 to move or remain in the left-hand position and the bar is moved to the right if a change of case is necessitated by the operated key-lever. In normal operation when there is no insertion of a case-shift signal, a cam 94 operating during the second half of the revolution of the cam sleeve 25 raises a latch member 65 to engage a step 189 on a detent 184 having an arm 186 which moves towards the pawl 60. The detent 184 is connected by a spring 185 to an arm 188 associated with a cam 63 having a flat portion which permits the detent to move further to the left to rock the pawl 60 so that the drum 49 is driven through a distance corresponding to one tooth of the ratchet-wheel 61. A T-member 70, similar to the members 33, and associated with projections 66, 67 on the bar 191, is rocked by the frame 30 early in the revolution of the cam 28 on the sleeve 25, and, if a change of case. is required, causes a lever 71 to rock a cam projection 196 so that the lever 65 is raised and supported on the step 189 of the detent with actuation of the pawl 60 by the first flat surface of the cam 63 and the action of the spring 62. The detent 60 and detent 84 are restored by the first raised portion of cam 63, and the pawl 60 is released a second time during the single revolution of the cam sleeve 25 by the cam 94 engaging the downwardly-projecting portion of the lever 65. The pins 52 remain in their outer positions for marking elements and are moved to their inner positions for spacing elements. For the insertion of the letter-shift signal, which is " all-marking," none of the pins is operated after the first step of the drum 49. If, however, a character signal is to be preceded by the figure-shift signal, the bar 191 is moved to the right and a signal which is enitrely marking except for the third code element has to be inserted before the code combination representing the character. The rightward movement of the bar 191 moves a pivoted spring-biased extension 69 to engage a step 91 on a lever 76 connected at 77 to a lever 78 which rotates under the action of a spring 80 and raises an arm 82 carrying a wedging member 83 which rotates a three-armed lever 85 so that its arm 87 is brought into the path of a cam 88 on the sleeve 25. The wedging member 83 also engages a projection 89 on the third pinsetting member 39 which is rocked about its pivot 51 when the projection on the cam 88 engages the arm 87. The arm 69 is supported on the upper surface of the step 91 and a cam 81 operates on the lever 78 to elevate the lever 76 which moves inward relative to the stop 75 with the end of the extension 69 still supported on the upper surface of the step 91-where it remains until the bar 191 is moved to the left when a character in the letter-case is to be transmitted. The return movement of the lever 78 also restores the three-armed lever 85 to its normal position. Operation of sensing frame and reading-off members. The sensing frame 101, Fig. 2, carrying the reading-off members 53 is rotated with the storage drum during the setting of the pins 52 and in the.reverse direction to read off the settings of the pins. As shown in Fig. 3, a gear-wheel 111 attached to the ratchet-wheel 61 engages a planet 112 meshing with a fixed wheel 113 forming a first differential gear. The planet 112 is rotatable on a shaft 114 carrying a gear-wheel 116 meshing with a gear-wheel 117 secured to the sensing frame 101 and a second gear-wheel 115 secured to a gear-wheel 159 driven from a wheel 118 on the sleeve 119 of the transmitting shaft, the gear ratios being such that a revolution of the wheel 118 drives the storage drum in the reading-off direction through a distance corresponding to one tooth of the wheel 61. When the drum 49 rotates under control of the pawl 60, the shaft 114 is rotated, since the element 113 is fixed, and as the element 115 of the second differential is fixed the wheel 116 drives the wheel 117 so that the sensing frame is moved a distance corresponding to the rotation of the drum 49. In the diagrammatic arrangement shown in Fig. 2, a pinion 121 meshes with a fixed reference rack 122 and a toothed segment 120 on the sensing frame 101. Rotation of the sensing frame 101 causes the pinion to move along the rack 122 and to rotate a shaft 123 carrying five pinions 124 mounted on a shaft 125 and each in mesh with an associated inner transfer rack 100 and an outer transfer rack 126. The inner racks 100 are mounted in guides 103, 104 fixed to the sensing frame 101 and the outer racks are mounted in fixed guides 127, 128 and biased towards an arm 137 by individual springs 138. The rotation of the sensing frame 101 and the shaft 125 carrying the pinions 124, in relation to the outer transfer racks, assumed to be fixed, causes the inner transfer racks 100 to be moved equally with the sensing frame. The arm 137 and an arm 132 are rigid with a third arm 134 associated with a cam 135 on the transmitter cam sleeve 119. The latter sleeve is driven by a ratchet clutch 200 operated by a lever 99 which is rocked by a pivoted lever 97 operated by a cam 96 released towards the end of rotation of the reading cam sleeve 25. The lever 97 is latched in its upper position by a spring-biased arm 141 and is held in the upper position so that the cam sleeve can make a number of revolutions, if necessary, until an arm 107 on the sensing frame 101 returns to its normal position in which it actuates the arm 141 so that it is moved away from the step 207 on the lever 97 which drops under the action of its spring 145 and disconnects the clutch of the transmitter cam-shaft. When the sensing unit is in its normal position an arm 129 formed with a step and ramp 131 engages the inclined end portion 130 of the arm 132 so that a lever 136 is unable to rotate clockwise although its arm 134 is opposite a low portion of the cam 135. When the sensing unit 101 has rotated counterclockwise the lever 136 is released to coact with the low portion of the cam 135 in the normal start position of transmitter sleeve 119. The release of the outer transfer racks 126 to follow the arm 137 allows pinion 124 to move the inner transfer racks in a clockwise direction so that projections 110 are obstructed or not by the ends of the sensing pins 53 and biased towards the pins 52 in the storage drum 49. Final storage and transmission of signal code combination. The selective movement of the outer racks 126 disposes pins 149, 150 relative to pivoted T-members 148 carried by a frame 146 operated by a cam 147. The settings of the T-members are t