Patent GB-654098-A (GB)
Title: Improvements in or relating to systems for automatically recording reservations of accommodation
Inventor: MCWHIRTER ERIC MALCOLM SWIFT
IPC: G08B5/22
Filed: 1948-04-27
Abstract: 654,098. Reservation of seats &c. STANDARD TELEPHONES & CABLES, Ltd. April 27, 1948, No. 11574. [Class 106 (iii)] A system for automatically recording reservations of accommodation comprises central automatic recording equipment, reservation positions, telecommunication means for intercommunication between the central recording equipment and the reservation positions, message receiving means in the central recording equipment a plurality of message registering means each adapted to register a particular class of information, means in the message receiving means arranged to detect message elements characteristic of each particular class of information, and means controlled by the detecting means for connecting the message receiving means to different message registering means in turn as the corresponding characteristic message elements are detected. In the described embodiment the equipment is adapted for use in connection with the reservation of seats in passenger aircraft. Bookings and enquiries can be made at a number of outstations which are in telegraph communication with a central office where booking records are maintained and from which information of available accommodation can be obtained. A stereotyped message is transmitted in telegraph code and the central office equipment includes means for decoding the message and storing it in registers until an end-of-message signal is received, when means operates to compare the message (e.g. request for a number of seats to be booked for a certain journey on a certain date) with the information standing in devices (called " ledgers ") registering the seats booked for each stage of the journey in question. If accommodation is not available booking cannot proceed and the equipment automatically commences a search to find alternative accommodation. If, however, accommodation is available, computing circuits calculate the new position to which the ledgers will have to be moved to record the booking. Before ledger settings are altered, a sequence of checking operations takes place, then, if the results of the check are favourable, the ledgers are set to the new positions. A booking having been made, a set of outgoing registers receive all relevant particulars and pass a message on to coding means whereby an answering message, which includes a repeat of the original message and, in the case of a booking, a serial number allotted to the transaction by means in the central equipment, is transmitted to the outstation. The whole transaction, i.e. the incoming message and outgoing answer, is also kept on a local record at the central office. Each outstation possesses a telegraph sender 500, Fig. 136, and a telegraph receiver 501 ; a broadcast receiver 502 for accepting general information sent out from the central office may also be provided. Any conventional telegraph equipment may be employed : in the preferred embodiment a tape sender 500 is used and an automatic telegraph printing receiver 501. Line switching circuits 510, Fig. 137, in the central office pick up a calling outstation and connect it to the booking equipment, other outstations being locked out until the picked-up station has completed the transaction and received the answer, or is thrown out by automatic timing means which clears down transactions delayed in the booking equipment due to faults. The following is an example of the type of message used : A3 *  F123 * D1212 * S4 * J124 * Z. A=action; 3= " book seats 1 " ;  *  is a " letter shift " signal and serves to separate the message into socalled " boxes " ; F123 signifies the particular Flight, e.g. London-Cairo ; D1212=date (12th December) ; S4=four seats ; J=Journey (124=London-Paris-Cairo) ; Z is the end-ofmessage signal. The received message is in the form of one of the " mark-space " start-stop telegraph codes and must be decoded by a device 511, Fig. 137, and stored in a form which can operate the remainder of the equipment. The method adopted is to cause each individual character to operate a characteristic relay in an appropriate part of a register 514. The decoder 511 comprises gaseous discharge tubes of the type having a main gap and a " trigger " gap connected in the manner of a pulse counting train, but arranged in a branching " tree," one tube being connected to two other tubes and so on. The two tubes are connected at their trigger electrodes to different pulse input terminals and though both are primed when the previous tube is fired only one can respond to the next pulse due to a controlling relay which is operated in one sense by a " mark " signal element and the other sense by a " space " signal element. Thus, of the two tubes in each case, one can be considered as a " mark " tube and the other as a " space " tube. Starting with a single tube, the decoder tree spreads out, in the course of five stages, to 32 outlets, and the outlet to which a count of five pulses will lead is determined by the combination of mark and space signal elements in the five unit code character applied to the tree. The 32 outlets represent the usual five-unit code characters, but not all of them are used. The required outlets are each connected to a set of relays, one for each letter, and each relay has contacts making active the register blocks of the incoming register 514, Fig. 137, characterised by the letters in the stereotyped message form. Thus, in a selected register block, Fig. 1, a relay A becomes energized via a conductor 1. Contacts a1 ... a10 are closed and join connections 2 ... 11 to relays OB ... 9B. The first digit of the numerical data following the alphabetical character which selected the block gives rise to a potential on one of the lines 2 ... 11 from the decoder. One of the relays OB ... 9B operates closing corresponding contacts to prepare a holding circuit from a line 12, and also energize a relay C, through a series of contacts which ensure that one only of the relays OB ... 9B is held. Similar one-up-only checking circuits are used elsewhere in the equipment. When a complete message has been received in the incoming register 514, the end-of-message signal (" Z ") initiates readout of the information in each register block by the placing of potential on the lines 13 energizing relays D, whereby closure of contacts d1 in each block completes a circuit from a line 18 to one of the lines 19 ... 28 to pass on the stored information. Connections 516 ... 520 from each " box " of the incoming register 514 (each marked with the appropriate box letter) lead to various parts of the equipment. " F " 516 leads to the flight circuits 521, Fig. 138, picking out the required circuit by means of a selector switch 527 or an electrical equivalent. The journey particulars consisting of digits each representing the position of an airport in the order in which it is encountered in the flight concerned, pass along the " J " connection 517, Fig. 137, to Fig. 138 and are directed to the chosen flight. The " D " connection 519 leads to a so-called " calendar " selecting a section of each flight  having a departure on the requested date. The selection of the requested flight causes the priming of a Sections circuit 529 ... 533, Fig. 141, individual to a flight and having one subdivision for each section (individual departure) made by that flight in the booking period, all the sub-divisions being primed. Each sections circuit sub-division is connected to one of the date connections, but all these connections are interrupted by " gates " 549 ... 553, Fig. 141, controlled by Journey Analysis circuits 554, Fig. 139, and only complete the connection to the sections of flights which cover the requested journey. The primed sections circuit is triggered in the correct section only under the influence of the date particulars, and other sections making the same journey are pre-set so that they are triggered in turn on a search. An eight-day booking period is provided for, the days of the current period being plugged up in jack panel 555, Fig. 142. Provision is made to meet the complications arising when the booking period falls partly in one month and partly in another &c. When the " D " connection 519 has selected the date and triggered the appropriate section sub-division of the sections circuit, a priming condition is passed to all the ledgers associated with the selected section of the selected flight. The ledgers are, preferably, electromechanical devices such as multipoint switches capable of being given various settings by driving over a number of contacts according to the number of seats to be booked, cancelled, &c. and means are provided for ascertaining the positions of the switches without moving them. The ledgers are shown diagrammatically in Fig. 140. Each of the small squares containing a circle represents a ledger which registers the seating capacity of an aircraft for one stage (segment) of a particular journey (flight) on a particular day (section). If the accommodation specified is not available, the equipment is designed to search for alternative accommodation, and since this may be found on another flight the over-all journey of which is different but which touches the required airports, the journey particulars are passed to Journey Analysis circuits 554, Fig. 139, which translate the digits into the named airports they represent in the particular flight and re-translate them back into different digits representing these airports in other flights. The other flights have their sections circuits preset in respect of the requested airports by the gates 549 to 553, Figs. 139, 141. Relay filters are provided to confine the search to flights in which the airports occur in the correct order. The " A connection 520, Figs. 137, 139, brings particulars of the nature of the transaction (A0=" zeroize ledgers"; A1= enquiry-" what accommodation available ... ?"; A2=" cancel"; A3=" book") to the action control 556 which