Patent GB-563524-A (GB)
Title: Improvements in or relating to communication systems
IPC: G08G5/00
Filed: 1941-04-07
Abstract: 563,524. Indicator systems. STEVENS, A. H. (Teleregister Corporation). April 7, 1941, No. 4631. [Class 40 (i)] An indicator assembly for displaying information about the progress of a number of flights of aircraft comprises a board in which numerical indicators are arranged in horizontal rows, each of which is assigned to a particular flight, the identification number of which is displayed on the first two indicators of the row. Two other indicators show the time and two more the altitude at which the craft in question is expected to pass a particular point or "fix." The flights associated with a particular " fix " have a group of adjacent rows assigned to them and the " fix " is indicated by a movable strip 367 secured above the group. The indicators are under the control of a local keyboard operator who can set up any desired indication and can also cause an indication displayed on one level to be moved to another level, the indications on the latter and on intervening levels being moved up or down automatically so that the order of the other rows of indicators is preserved. The indicators are also under the control of distant teleprinters linked with the station by wire or radio. To change an indication a teleprinter operator sends a series of six numerals for each category of information to be changed and then an end of message signal. The first two numerals of each series identify the flight, the third the " fix " in relation to which the information is given and the fourth the category of the information (time or altitude in the system shown). The two remaining numerals convey the information itself. These messages are recorded on a monitoring teleprinter and registered on relays for transfer to the indicators. The information is automatically directed to the row of indicators of which the flight indicator and the " fix " indicator (the latter being separate from the indicator board) are already set in accordance with the night and fix digits received. An alarm lamp is operated if a mutilated or otherwise inappropriate code is received. Recording and registering incoming message. Signals received perforate a tape which subsequently controls a retransmitter such as TTR1, Fig. 1. In response to the " end of message " signal, relays E M1 ... E M4, which are operated, normally without effect, in parallel with the perforator magnets, energize a relay L which locks and causes a hunting- switch SS to move to a position characteristic of the operative receiver and energize a relay TC for connecting up the proper retransmitter, and the latch magnet SM1 of a distributer DR1. The latter, in the even positions from 2 to 12, connects the retransmitter to six groups of register relays II1 ... II5, 2I1 ... 2I5, &c., Fig. 5, and in the odd positions controls the stepping-on of the transmitter tape and the operation of the printing magnet PM of the monitoring printer MP, Fig. 1. Selection of appropriate indicator row.-In positions 13 to 22 of DR1, test circuits are made in succession for relays GA0 ... GA9, Fig. 3, one of which corresponds to each row of indicators, over circuits which involve wipers 1T0 . . . 1T9, 1U0 . . . lUg and FS0 . . . FS9, which moved with the corresponding identification and " fix " indicators, and contacts of the identification and " fix " registering relays. The relay GA of the row of which the wiper settings and the relay settings correspond pulls up and prepares restoring circuits for the indicators of which the setting is to be changed. Restoration and resetting of indicators.-In its final position, DR1 starts up a second distributer DR2 which in the even positions from 4 ... 22 energizes a relay P7 to give restoring impulses to the magnets of the indicators selected by the operated GA relay and the category relay TIME or ALT operated by the register relays R1 ... R5. The indicators open the restoring circuits on reaching normal as at 96, 106, Fig. 3. In position 24, a relay AG energizes the relay G corresponding to the operated GA relay to prepare operating circuits for the appropriate indicators. In positions 26 to 44, P1 operates once, P2 twice, P4 four times and P7 seven times. Contacts of these relays are connected to the tens and units indicator magnets via contacts of the register relays DT1 ... DT5 and DU1 ... DU5 and the indicators are thus stepped in accordance with the digits registered. At the end of its travel, DR2 energizes REL which releases AG and,the register relays whereupon TIME (or ALT) and the operated G and GA relays are released. If the message includes a further group of numerals, the arrival of DR2 in its normal position starts up DR1 and the cycle is repeated to change other indicators. 'The end-of-message signal operates a combination of relays RS1 ... RS4 so that when DR2 reaches position 5, RS5 is operated to release L &c. and enable the indicator-setting apparatus to be associated if necessary with another teleprinter receiver or with the local keyboard. Release of L is prevented, however, by tape-operated contacts 25 if there is another complete message waiting on the same tape. Setting indicators from local keyboard, Fig. 2.-A key is pressed characteristic of the level of the indicator to be set, then keys corresponding to the tens and units digits of the new indication and finally a key to select the category of the indicators to be changed (e.g. IDENT, TIME or ALT). The level and tens and units keys remain latched until a new key in the same group is operated. The category key is latched under control of a magnet KR. This latter key energizes a relay K which causes the switch SS to move to a position characteristic of the keyboard and to energize a relay KS to associate the keyboard with the control arrangements. In this case latch-magnet SM1 of distributer DR1 is shunted out and the distributer remains stationary but DR2 is started. Circuits are made via the keys for the appropriate G and GA and category relays and the restoring and resetting of the selected indicators takes place as described in the preceding paragraph except that the tens and units keys play the part previously performed by the tens and units register relays. The operation of REL then releases all operated relays and the distributer comes to rest. Transferring indicator setting to a new level.- The operator presses the " horizontal position " key of the old level, the " change position " key of the new level, the " fix " key of the group concerned, the zero keys of the tens and units groups and finally a key SEQ. Relays SEQ, SEQ1, KS, IDENT, TIME and ALT are operated and also, if the new position is above the old, relays TR, TR1, TR2 and TR3. A circuit is made also for the G relay of the old level and circuits are made whereby a switch STM, Fig. 7, hunts for a position characteristic of the new level over its wiper C. A relay SR, which is operated in the driving circuit, falls back when the switch stops and energizes SD to operate the latch magnet of distributer DR2. The latter in passing position 2 gives an impulse to ST to drive STM one step and cause the operation of HG1, HG2 and the GA relay corresponding to the operated G relay. In the new position of STM, a relay M1 (or M2) is operated to connect a group of registers 1TS1, 1US1, &c. or 1TS2, 1US2, &c. in parallel with the indicators of the old level. In positions 4 ... 22 these indicators are restored as previously described and the registers are set to the complements with respect to 11 of the previous indicator settings. In position 23, an impulse is given to ST to energize GAR and step on STM which releases M1 (or M2). The operated GA relay falls and relays A2, M2 (or A1, M1) pull up to associate another set of registers. On this occasion the remaining positions are traversed idly. REL energizes GC, GC1, the operated G relay is released and ground is applied to wiper G, GA. The distributer latch magnet is held and a new rotation begins. In position 2, STM is stepped on, releasing A2 (or A1), but holding M2 (or M1). Relays G, GA of the new level are operated over wipers G, GA of STM and the indications on this lever are transferred to the second register set in positions 4 to 22. In position 23, STM is given another step, the GA relay and relay M2 (or M1) are released and A1 (or A2) pulls up. The first set of registers is thus connected in parallel with the indicators of the new level and during the second half of the rotation the registers are restored and the indicators are set. During the third rotation, the indications at present on the indicators next above or below those to which the information has been transferred according to the condition of relays TR is stored on the available register set and the previously stored information is transferred to those indicators. The moving up or moving down of information continues until the indicators from which the information was transferred are reached as indicated by the depressed key in the " horizontal position " set. A circuit over the key and wiper CP is made for EQ so that on the operation of REL, when the last of the stored information has been taken up, magnet KR is operated to release the key SEQ, and all operated relays fall back and the distributer stops. Control of " fix " storage indicators.-There is one of these for each level of indicators and they are set by operating the appropriately numbered " fix " key, the " horizontal position " key of the indicator to be changed and the key FS. The switch SS is set as previously described to a " keyboard " position, the appropriate GA relay is energized and the distributer DR2 is started up. During the first part of the rotation, restoring impulses are sent to the indicator unless or until it is in its normal position. In position 24, AG pulls up to operate the corresponding G relay and this causes impulses to be sent to the indicator to a number dependent on the particular " fix