Patent GB-447196-A (GB)
Title: Improvements in or relating to telegraph keyboard-controlled code-translating apparatus
IPC: H04L17/04
Filed: 1934-11-12
Abstract: 447,196. Type printing telegraphy. GRIFFITH, R. G., Montclair, Crewes Avenue, Upper Warlingham, Surrey. Nov. 12, 1934, Nos. 32522/34 and 27/35. [Class 40 (iii)] In a code-translating mechanism permutations set up on a set of combination members are each translated into two permutations each consisting of a smaller number of elements set up on a set of impulse selecting members. In the embodiment described, upon the operation of a character key a six unit combination is set up, one of the units depending on the case in which the character lies, and translating mechanism converts this combination into a five unit case combination and a five unit character combination. These combinations are only both transmitted at the commencement of a transmission, when the keys are operated at below a predetermined rate or when the case signal combination differs from the previous case combination. Setting up six unit combinations. Depression of a character key 1 depresses a selector frame 4, projections 7 on which set the pivoted vanes 8, 8a in one of two positions. The six vanes 8 move the frames 10a ... 10f either up or down, and the vane 8a moves a frame 19 to trip the shaft 15 by releasing one of the two stop surfaces of a member 23 thereon. The shaft 15 is thus released for half a revolution and the double cam 16 thereon moves the lever 17 to and from the frames 10. This movement locks the frames 10 by placing a locking bar 30 either above or below the pointed projections 14 thereon and also tilts the levers 26 either clockwise or anticlockwise depending on which of the upper or lower projections 12, 13 respectively on the frames 10, engages one of the projections 28, 29 on the levers 26. Movement of the latter is converted into longitudinal movement of the bars 32a . . . 32f through bell-crank levers 31. Translating from six unit to five unit code. Movement of the bars 32 locks or unlocks through members 49, Fig. 2, the lower ends of levers 50 which hence become able or unable to rotate the bell-crank levers 53, 53f, when engaged by cams 51 on a shaft 33 which is released during the rotation of the shaft 15 by members 39, 44 linked by a bar 41. The five levers 53 set up a five-unit character combination on the bars 72a ... 72e by locking the upper end of either a lever 69 or 73 depending on the release or non-release of a member 54 by the lever 53, cams 70 on a shaft 34 actuating the locked lever to move the bar 72 either to the right or left. The members 54 are restored to the position shown by cams 112 on the shaft 34. The other five unit combination for the case signal involves selection of the position of the middle bar 72c only and is accomplished by a member 75 linked to the member 54f which is controlled by the sixth lever 53 shown as 53f. Thus when the shaft 35 rotates, the middle bar 72c is moved to the right or left according to the position of the member 75 by the cam 80 while the other four bars 72 are moved to the left by cams 120. Control of transmitting contact. Extensions 94a ... 94e on the bars 72 lock or unlock the ends of levers 96a ... 96e so that they are effective or ineffective to raise the bar 99 when operated in succession by cams 98a ... 98e on the shaft 36 which is released for half a revolution by the member 89 operated from either of the shafts 34, 35 through members 86 or 124 through the bar 151. A shaft 103 geared to the shaft 36 is moved longitudinally by the bar 99 through lever 108 so that a cam 104 thereon moves the lever 107 either to the right or the left to position the transmitting contact 110 to one or other of its co-operating contacts 109, 111. The start and stop signals are determined by a further uncontrolled lever 96 operated by cam 98. Sequence of operations. The case signal is transmitted when a character key is operated involving a case shift, when first starting up from the idle position, and whenever the speed of signalling falls below a predetermined rate. Thus when the depression of a key involves a case shift, a movement of the bar 32f results, and a hump 113 thereon lifts a detent 114 to release the shaft 35, and the case signal is transmitted. Immediately after wards the shaft 34 is released to set up the character combination which is subsequently transmitted. Also in starting up from rest, the first movement, of the shaft 15 operates the rod 141 through cam 138 and lever 139 which moves the member 146 through linkwork, 143 ... 145. This movement operates the trip lever 114 to release the shaft 35 for transmission of the case signal. When any of the connecting rods 88, 41, 58 is out of its position of rest, one of the inclines 151 .. 153 thereon lowers the lever 146 out of the range of the member 145. Cams 130, 131, levers 132, 133 and stop members 134, 135 provide overlap mechanism ensuring that only one of the shafts 34, 35 can be operative at any one time. Specifications 439,745 and 448,846 are referred to.