Patent GB-613417-A (GB)
Title: Improvements in or relating to telegraph transmitters
IPC: H04L17/12
Filed: 1945-01-15
Abstract: 613,417. Printing-telegraph transmitters. TELETYPE CORPORATION. Jan. 15, 1945, No. 1197. -Convention date, Dec. 20, 1943. [Class 40 (iii)] A telegraph transmitter comprises a plurality of devices for feeding control forms, such as perforated tapes containing signal code combinations past an arrangement common to said devices for sensing the code combinations on the forms so that the corresponding signals are transmitted and means provided in common for the devices, to arrest one and initiate the operation of another of the plurality of formfeeding devices. One of the forms may embody the message for transmission, whilst a second form, brought into operation by a predetermined sequence of code combinations on the message form, may incorporate message numbering or designating signals. The number tape 92 and message tape 93 are advanced by sprockets 89, 91 secured to ratchets 84, 87 respectively which are stepped by pawls 66, 67 selectively brought to the driving position. The pawls 66 and 67, biassed towards the operating position by springs, are formed with oppositely bent ears pivoted on a shaft 65 carried by a lever 63 which is rocked by a cam 88 mounted on the shaft 18 carrying the cam assembly co-operating with the transmitting goose-neck levers 29. The bent extensions of the pawls 67, 66 are provided with arms 68, 69 selectively operated by the lateral movement of a control rod 71 to rock the associated pawl out of driving position. The control rod 71 is carried by a bracket 74 having one end pivotally supported at 77 by an arm 78 attached at its upper end to a bell-crank lever 81 associated with a crown cam 94 mounted on the shaft of the sprocket 89. The other end of the bracket 74 is supported by a lever 76 pivoted at 83 and having a lug 118 on its upper arm associated with ledges 115, 116, 117 carried by pivoted levers 112, 113, 114, respectively. The ledge 117 on lever 114 is higher than the ledge 115 on lever 112 which lies above the ledge 116 on lever 113. The transfer of the drive to the number tape 92 is effected by sequential code combinations corresponding to figures-shift and the letter " J " followed by the rub-out signal. Pivoted levers 45 carrying probing pins 47 have extensions 54 with bifurcated ends which co-operate with the horizontal extensions of the goose-neck levers 29 to control the transmission of the elements of the signal combination and in addition to allow a figures-shift bail 55 to move upwardly when the figure-shift signal has been detected. An extension 132 of the bail 55 extends under a pivoted latch 128 normally restraining the rightward movement of a lever 121 provided with a pin 119 associated with the levers 112, 113, 114, and a pivoted catch 135 holds the latch 128 in its lifted position. The latch 128 is returned to the position in which it restrains the bar 121 by operation of the pivoted catch 135 by an extension 137 formed on a lever 138 lying adjacent the horizontal portion of the third goose-neck lever 29. A lever connected to the third bar 45 has a bent portion 139 which extends across the ends of the third goose-neck lever and of the lever 138 and is removed from the obstructing position when the third code element is a marking impulse. The lever 138 rotates counter-clockwise when its projection engages a recess in the associated cam on the shaft 18 and its extension 137 rocks the catch 135 to release the pivoted latch 128. The third elements of the code combinations for " figureshift " and the letter " J " are spacing and do not release the latch 128 from its lifted position. The lever 121 when unlatched is moved to the right by a spring 124 when a pin 122 carried by a lever operated simultaneously with the restoration bail 57 moves in the slot 123 in the lever 1'21. The rightward movement of the pin 119 on the lever 121 moves lever 113, lever 112 rotates counter-clockwise under the action of its spring and the lever 52 is rotated to bring a bail 51 into contact with the ends 49 of the levers 45. The arm of the bell-crank 76 is still supported by the ledge 117 when the lever 121 and its pin 119 return to normal position since the bail 51 is blocked by the disposition of the ends 49 of the bars 45. If the succeeding signal is the letter " J," the bail 51 moves into aligned recesses at the ends of bars 45 and the additional movement of lever 52 is transferred to the bar 121 so that its pin 119 engages the lever 114 removing the tooth 117 from beneath the lug 118. The arm of the lever is now supported by the tooth 115, the lever 112 in its forward position, and as the bar 121 returns leftwardly the tooth 115 is removed from lug 118 which drops on to the tooth 116 on the lever 113. During the succeeding signal-the rub-out signal-the movement of the lever 113 by the pin 119 removes the supporting tooth 116 and the bell-crank 76 rotates clockwise to move the bracket 74 and the control rod 71 to the left, thereby bringing pawl 66 into driving engagement with its ratchet 84. The code perforations following the letter " J " on the tape 93 are all marking so that the pins 47 freely pass through the lower tape to probe the perforations of the upper tape 92. After a predetermined number of steps-for example, six-an arm 149 of a pivoted bell-crank 81 engages a recess in the crown cam 94 and raises the end of the bracket 74 so that its extension 148 is engaged by the lower end 125 of the lever operated with the restoration bail 57. The bracket 74 is moved to the right and the control rod 71 disengages the feed pawl 66 and the pawl 67 is restored to the driving position. At this stage a pivoted pawl 90 carried by the lever 63 engages behind one of five teeth formed on a sleeve 95 on the shaft 85 of the ratchet 84 and on the following actuation of the lever 63 moves the ratchet 84 and the upper tape 92 through one step so that an all'-marking signal of five perforations is disposed above the lower tape 93 and the feeler pins 47. When transmission is to be resumed after a stoppage due to the failure of tape supply or to a tape breakage, a pin 105 on a manually-operated lever 106 engages a threearmed lever which disengages the driving pawl 67 and the holding pawl 99 from the ratchet 87. A pin 108 on the lever 106 engages the arm 38 of a latch member to release the end 37 of an extension 35 of a goose-neck lever which in its latched position opens the line circuit. The bracket 74, if in the left-hand position when transmission ceased, is restored to its normal right-hand position by a pivoted lever 153 which is engaged by a projection 156 at the bottom of the lever 106. In a modification, Fig. 8, the transition from the auxiliary or number-indicating tape 92 to the message tape 93 is effected by a pivoted lever 161 having a shaped end 158 which is actuated by a sixth perforation or a marginal slit in the tape to effect vertical movement of the rod 78 so that an extension 148 of the bracket 74 is engaged by the portion 125 of a lever moved rightwardly simultaneously with the restoration bail 57. The transmitter may be restricted to message transmission by latching the free end of the bell-crank lever 76 on a ledge 169 of a manually-operated lever 168. U.S.A. Specification 2,296,845 is referred to.