Patent GB-844261-A (GB)
Title: Improvements in printing telegraph apparatus
Inventor: HANDLEY JOHN
IPC: H04L13/08
Filed: 1957-08-09
Abstract: 844,261. Printing telegraph transmitters. CREED & CO. Ltd. Aug. 8, 1958 [Aug. 9, 1957]. No. 25127/57. Class 40(3). In keyboard-controlled printing telegraph apparatus in which the actuation of a key selectively moves code bars in accordance with the combination of elements of the character designated by the key, and in which case-shift combinations are employed, the operation of a key representing a character in a case different from that of the character represented by the immediately previous actuation of a key lever controls means for preventing movement of the code bars and for operating auxiliary members to set up the appropriate case-shift signal, and the termination of this operation resets the auxiliary members and controls means to release the code bars to set up the code combination corresponding to the key which has been actuated. In a modification, the apparatus includes a mechanical device arranged to store a number of code combinations, since the rate of keyboard operation may effectively set up the resulting selections at a rate greater than the corresponding signals can be transmitted. The actuation of any key lever, such as 9, depresses a release bar (not shown) engaging a projection 11 to operate a rocker 150 carrying a pivoted pawl 12 engaging and rotating a rocker 13 having an arm 14 which rotates a further rocker 7 having a transverse extension normally engaging projections 38 on the underside of code bars 1-5 and freeing those code bars which do not carry projections 8 engaged by the actuated key lever to move to the right under the action of their springs 6. A trip bar 34 has downward extentions in which sleeves 156, 157 are mounted, the sleeve 156 carrying a pin 33 engaging the pawl 12 and the sleeve 157 carrying a pin 158 engaging the right-hand side of a lug on a locking bar 35. The trip bar 34 moved to the right on the actuation of any key lever allows movement of the locking bar 35 which carries projections or teeth 32 engaging in a hole of the actuated key lever and lying under all the other keys so that the keyboard is locked. The trip bar 34 when moved to the right also operates a detent to allow the transmitter shaft 27 to rotate for one revolution. The selective movement of the bars 1-5 rocks pivoted members 15-19 to move selectively in the vertical direction five levers 20-24 which are locked in their set positions by a bail 28. Five three-armed sensing members 97-101 pivoted at 169 have horizontal arms engaging sequentially arranged recesses on a cam sleeve on the shaft 27 and downwardly extending arms which are latched by the members 20-24 in their upper positions. The third arms of the members 97-101  engage a contact-actuating frame 103 and when a lever 20-24 is in its lower position the associated member 97-101 is free to rock counter-clockwise when its horizontal arm engages the corresponding recess in the cam sleeve and through member 116 to move the contact member 106 against its appropriate contact. Towards the end of a revolution of the shaft 27 a cam operates a reset rocker 37 to move to the left those bars 1-5 which had been permitted to move to the right, and the trip bar 34 which takes with it the locking bar 35. Automatic case-shift insertion. A case-shift control bar 39 movable to one or the other of two positions is formed with inclined teeth engaged by the key levers, such as 40, 41, 42, and is in the right-hand position for the letters case and in the left-hand position for the figures case. On the actuation, for example, of a character key necessitating a change from the lower case to the upper case, the bar 39 is moved to the left and a projection 47 on the lower side of the bar engaging a projection 174 on a member 48 rocks it so that an extension 48<SP>1</SP> engages projections 51 on the code bars to prevent their movement to the right. In addition, the movement to the left of the bar 39 moves a projection 61 to the position 62 in which a lever 50 is locked, but a companion lever 49 is unlocked so that a rotatable lever member 55 is released for rotation, and by its bail portion 55<SP>1</SP> extending underneath the code bars 1-5 engages code projections 63 on extensions 56-60 slidably mounted on the 1st, 2nd, 4th and 5th bars to operate the rocker members 15-19 to move the bars 20-24 to set up the figureshift signal. Also the lever 49 is rocked so that its end engages the extension 177 of member 48 to hold it in position for engagement of its extension 48<SP>1</SP> with the projections 51 on the code bars. In the case in which the bar 39 is moved to the right for the change to the lower or letters case, the lever 50 is unlocked so that the lever 54 can rotate and by its extension 54<SP>1</SP> engage projections 64 on the lower side of all the extensions 56-60. After the appropriate case-shift signal has been transmitted, the rocker 37 is actuated to return the sliding extensions to their original position, and also to restore the lever 54 or 55 which had been operated so that the corresponding lever 49 or 50 is returned to the position shown in which it releases the member 48 to disengage from projections 51 and in which it is held by the horizontal extension 177 of the member 48. Also the initial rocking of the member 48 releases a rail 52 which is rocked by a spring 179 so that the portion 52<SP>1</SP> moves backwardly and the sleeves 156, 157 are moved relatively to the trip bar 34 with the result that the pin 33 is moved clear of the pawl 12 and pin 158 is moved out of engaging relation with the lug on the locking bar 35. The trip bar 34 and locking bar 35 move to the right in the normal manner, but the locking bar 35 is not returned with the trip bar 34 after the setting up of the case-shift signal so that the operated key lever remains locked. When the rocker 48 returns to the position shown in Fig. 2, the extension 48<SP>1</SP> is disengaged from. the projections 51 and the rail returns to its normal position in which the pins 33, 158 are in position to engage respectively the pawl 12 and the lug on the locking bar 35. When the trip bar 34 moves forward to set up the code combination, the pin 158 is pushed inwardly by a cammed surface on the lug and then engages behind the lug on the bar 35 so that after the code combination corresponding to the actuated key has been set up, the return of the trip bar 34 will take with it the locking bar 35 so that the keyboard is unlocked for further actuation of a key. Signal storage arrangement. The signal elements are stored on a drum 70 in twelve circumferential rows, each comprising five radially movable pins 71 frictionally held by intervening spacers 72 and end springs 73. The pins are set by five pusher rods 77-81 disposed for axial movement in slots in a rotatably mounted housing 87 and carrying at their ends discs 181-185 which are engaged and selectively moved by forked members 201, 202, Fig. 11, rotated by crank pins 195-199 in engagement with the ends of the code bars 1-5. A cam 183, Fig. 9, driven by a ratchet 184 on a continuously rotated shaft 182 when a lever 187 controlled by the trip bar 34 is in the position shown and the cam in this position operates a rod 194 to return the code bars 1-5 to their normal position and also a rod 193 to return the cranks 195-199 to their normal positions. The trip bar 34 in its movement to the right also rotates a crank 203 controlling a link 92 which brings the head of a pivoted pawl 93 out of engagement with projections 204 on the pin drum housing to allow the housing 87 to be rotated clockwise until the tail of the pawl engages another projection 204, and when the crank 203 is moved back at the end revolution of the cam 183, the link 92 moves back so that the head of the pawl engages the next projection 204 on the housing of the storage drum 70. When a signal has been stored on a row of pins, a finger 96 on the pusher housing allows a rod 206 to move upwardly so that a detent 207 is moved by spring 209 out of engagement with a detent 210 so that the transmitter shaft 27 is set into rotation, and the combination levers 211-215 selectively set by the pins 71 and latched by bail 28 are sensed by five three-armed levers 97-101. Towards the end of a revolution of the shaft 27 a restoring bail 216 raises all the levers 211-215 to their upper positions and a pawl member actuated by a cam on the shaft 27 steps the drum 70 to bring the next row of pins 71 to the operative position with respect to the ends of the levers 211-215. The pins 71 which have been moved outwardly are reset by a curved flange 219. If the number of combinations set up on the rows of pins approaches the capacity of the drum, the pin 96 on the pusher housing operates a lever 225 to engage a pawl 227 mounted on the locking bar of the keyboard, so that further key operation is prevented until some of the stored signals have been transmitted and the locking lever 225 restored by its spring 226. This storage arrangement forms the subject-matter of Specification 844,262.