Patent GB-478817-A (GB)
Title: Improvements in or relating to typeprinting telegraphy
IPC: H04L17/06
Filed: 1936-07-27
Abstract: 478,817. Type-printing telegraphy. ESTOUP, J. July 27, 1936, No. 20681. Convention date, June 24. [Class 40 (iii)] [Also in Group XVI] In start-stop teleprinter apparatus designed to permit rhythmed transmission at the maximum prescribed speed, the keyboard has differential locking means, described in a later paragraph, whereby a second key may be depressed by the amount by which a previouslydepressed key has risen. When a key is fully depressed, its setting is recorded on five electromagnets with two-position armatures and a transmission shaft is started, a pin on the shaft giving a shock to the finger to indicate that the key has been effective and may be released. The transmission shaft starts also a " translation " shaft which effects the setting of transmission contacts in accordance with the record on the magnets and also controls the setting of combination comb members for effecting local printing (in red) of the signal transmitted. At the receiving end the signals are recorded on the same five magnets which are used for transmitted signals and the translation shaft is again operated to effect the printing (in black). The maximum speed of operation is governed by the time of revolution of the transmission shaft which, if a second key has been depressed at the end of one transmission, continues through its normal position without a pause. Specification 459,646 is referred to. Circuit arrangements, Fig. 3. On the closure of contacts 1 ... 5 by the depressed key in accordance with the code to be transmitted, condensers 12 ... 16 are discharged rapidly through the appropriate windings of magnets 6 ... 10 respectively causing their armatures 80, Fig. 5) to be positioned to record the signal after which the transmission contacts 22 ... 26 are correspondingly set. The transmission shaft first opens contact 27 and closes contact 28 to prevent operation of the receiving relay 36 during transmission and then successively closes contacts 29 ... 35, the first sending a negative start signal and the last a longer positive stop signal. At the receiving end, relay 36 operates on the start signal closing contact 38, whereupon magnet 40 is operated by condenser 41 to start the receiving shaft. The successive closure of contacts 43 ... 47 connects the contacts of relay 36 to magnets 6 ... 10 in turn and the stop impulse is then effective over contact 48 to restore relay 36 to its normal position. Keyboard mechanism, Fig. 4. The keys 50 are associated with five pairs of comb members 51, 52, the members of a pair having complementary projections and recesses so that one member of each pair, according as the corresponding impulse is to be positive or negative, will move for each key depressed. The combs are pivoted to pairs of angle members 56, 69 connected by bars 59, 70 to give parallel movement, the member 69 carrying a pin 75 engaging with the member 56 to provide the differential locking referred to above. Since any two signals differ in sign in at least one of the impulses, the locking will be effective in at least one of the pairs of combs for every other key. The depressed comb of each pair closes a contact 65 or 74 which together correspond to one of the sets of contacts 1 ... 5, Fig. 3. The depressed comb of one of the pairs also operates a lever 76 to start the transmission shaft 102, Fig. 6. Recordirig mechanism, Fig. 5. Each magnet 6 ... 10, Fig. 3) comprises a web 77 with coils 79, polepieces 94, permanent magnets 92, and a pivoted armature 80 which remains in the position to which it was last moved. When the armatures have been positioned in accordance with the key depressed, levers 86 are rocked under the control of the transmission shaft against the forked ends of the armatures causing the corresponding positioning of typebar selecting combs 151 and the operation of the transmission contacts 153 (contacts 22 ... 26, Fig. 3). Transmission shaft, Fig. 6. The operation of lever 76, Fig. 4, pushes lever 120, Fig. 6, causing arm 117 to move out of engagement with lever 116. Levers 116, 110, 106 then move together under the action of a spring 103 controlling a pivoted finger 100 so that roller 105 is moved put of the slot in cam 104 and pawl 98 engages with driving wheel 96 to rotate shaft 102. Shortlv after the shaft has started, a pin 125 hits arm 126 to give a shock to the finger and rotates arm 124 which moves finger 123 free of arm 117, this relationship being restored when the depressed key is released. Arm 124 also controls through link 128 the starting of the translation shaft through clutch mechanism similar to that shown in Fig. 6 and this shaft controls by a cam the lever 149, Fig 5, which effects the rocking of levers 86. Staggered cams 131 on the transmission shaft successively control contacts 132 (corresponding to 27 ... 35, Fig. 3), and a further cam 108 acts on lever 110 to restore the locking of lever 116, lever 110 moving relatively to lever 106 by means of a slot connection 115 until the revolution is complete when the roller 105 drops into the recess in cam 104 and the pawl 98 is unclutched. Local printing, Fig. 5. A cam on the translation shaft acts through lever 162 to rock bar 165 to lower testing members 166 on to the combs 151, and a projection 167 on the selected testing member is engaged by the upper edge of bar 165 causing the type-bar 172 to be operated through links 169, 171. Link 169 through bar 176 and lever 178 also effects spacing. The ribbon-holder 183 is moved to the red position by links 181, 180, 136 controlled by a cam 133 on the transmission shaft, Fig. 6. Reception. Magnet 40, Fig. 3, controls clutch mechanism similar to that shown in Fig. 6, for the reception shaft which successively operates contacts 39 ... 48, Fig. 3, for distributing the code signals to magnets 6 ... 10, and then starts the translation shaft which controls the printing in the manner described in the preceding paragraph, the ribbon-holder 183 being, however, moved to the black position only through links 181, 180 and lever 178.