Patent GB-757125-A (GB)
Title: Automatic toll ticketing
IPC: H04M15/04
Filed: 1954-03-26
Abstract: 757,125. Automatic exchange systems. STROMBERG CARLSON CO. March 26, 1954 [April 13, 1953], No. 8944/54. Class 40 (4). In an automatic ticketing system each outgoing trunk circuit is equipped with its own individual trunk recorder which records magnetically the information in respect of all calls handled by that trunk circuit, and once each day each trunk recorder plays back its recorded information to a common printer which then prints the tickets for the calls. Operation-general: Figs. 1, 2. The exchange network described comprises three automatic exchanges 7, 8 and 9, calls between which are assessed on a time basis, ticketing equipment being located in each exchange. Assuming that subscriber A of exchange 7 wishes to call subscriber C of exchange 8, he dials the digit indicative of the wanted exchange, in response to which the selector 14 seizes a free trunk circuit, such as 19, and extends the calling loop thereto. The caller then dials his own directory number which is repeated by the trunk circuit 19 to set a verification switch train 23, 24 in order to check the identity of the calling substation. Provided that this check is successful, the trunk circuit 19 is conditioned to repeat subsequent dialled digits to set the switches in exchange 8 to establish connection with the wanted subscriber. Each one-way trunk circuit such as 19 has its own individual trunk recorder 25 which records on an endless magnetic tape all the information concerning calls handled by that trunk circuit, the tape having sufficient capacity to store this information in respect of more than the normal number of calls handled by the trunk circuit in twenty-four hours. Each trunk circuit is also equipped with a preselector (22) giving access to an idle verification selector (23). In order to record the elapsed time of a call, a common time pulse generating circuit 26 is provided; and a common clock and calendar circuit 27 provides time and date information. A D.C. erase supply source 29 serves to erase the magnetically recorded information after it has been played back to a printer. The playback control circuit 30 successively associates the playback facilities with idle trunk circuits by means of a trunk circuit selecting switch and feeds the stored information via amplifier circuits 31, 32, 33 and 34 to the various digit storage chains 38, and to the cost computer 39, under the control of steering circuit 37. The printer 36 is preferably of the type sold under the name " Flexowriter " by the Commercial Controls Corporation of Rochester, New York. Each digit dialled is also repeated to the trunk recorder 25, each impulse being recorded as a mark signal on the tape; and at the end of each digit the trunk circuit 19 transmits a space signal which is also recorded on the tape. If the caller has dialled his own number, the verification test results in the establishment of a through connection between the sleeve lead of switches 23, 24 and that of switches 13, 14, and the trunk circuit is automatically conditioned to repeat subsequent dialled impulses over the trunk 20. If the caller has not dialled his own number, the trunk circuit does not establish a dial impulse repeating loop over the trunk 20, but signals to the caller that the call cannot be completed. The caller then hangs up, line circuit 11 and link 12 are released, and the trunk circuit transmits an end-of-call signal (coincident mark and space signals) to the trunk recorder 25, followed by several advance pulses to step the tape on. Immediately the verification test is completed (whether it be successful or not), the trunk circuit 19 removes ground from the sleeve lead of selector 23 and the verification switch train is released. On the reply of the called party, the trunk circuit 19 associates the time pulse generating circuit 26 with the recorder 25 and pulses at one minute intervals are recorded as mark signals on the tape, until the called party hangs up. When the caller hangs up, the trunk circuit 19 opens the loop over the trunk 20 to initiate the release of the switching equipment in exchange 8, removes holding ground from the sleeve of the trunk 19a to release the line circuit 11, finder 13, and selector 14, and then reconnects the ground to guard the trunk circuit against seizure before it has completed the recording operations. The trunk circuit 19 transmits a space signal to the recorder 25, and then associates the recorder with the scanning circuit 28, which, in accordance with the setting of the clock and calendar circuit 27, feeds mark pulses to the recorder indicative of the month, day, hour, and minute at which the call terminates, each digit being followed by a space signal from the trunk circuit 19. Thereafter, the trunk circuit transmits an end-of-call signal followed by five or six tape advance pulses, and then removes the guarding ground potential from the sleeve of the trunk 19a. Called line busy. The time pulses and time and date digits are not recorded, and the end-ofcall signal follows immediately after the calling and called numbers. This is subsequently recognised by the playback equipment as indicative of an unsuccessful call, and no ticket is printed. Playing back. Normally this takes place once during each twenty-four hour period, the trunk circuits being sequentially associated with the translating and ticket printing equipment by the trunk-selecting switch. When the wipers of this switch are set to the. trunk circuit 19, a busy test is carried out, and if the trunk circuit is idle, the playback control circuit 30 seizes it and applies ground to the sleeve of trunk 19a. Separate pulse transmission paths are established between the mark and space heads of the recorder 25 and the mark and space preamplifiers 31 and 32, respectively. The trunk circuit 19 energizes the clutch magnet of the recorder so that the tape is driven forward to its normal or start position, by a common drive shaft. The playback control circuit 30 grounds the destination lead 8a, extending to the printing control circuit 35 to indicate that the trunk circuit seized leads to exchange 8, and resets all the storage chains 38 to normal. When the record tape reaches its normal position, contacts are closed in the recorder 25 which signal this fact to the trunk circuit 19 and the playback control circuit 30, connect the erase supply 29 to the erase head of the recorder, and cause control of the clutch magnet to be transferred from the playback control circuit 30 to the printing control circuit 35. The information recorded in respect of a successful call consists of two groups of four digits, each of from one to ten pulses, representing the calling and called parties' numbers respectively, a series of time pulses indicative of the elapsed time of the call, a digit of from one to twelve pulses designating the month, and a series of six digits, each of from one to ten pulses, designating the day, hour, and minute the call was completed. All these pulses are recorded as mark signals on the tape, the digits are separated by space signals, and the end-of-call signal (mark plus space) follows the last digit. The first signal played back is an end-of-call signal which causes the printing control circuit 35 to set the steering circuit 37 so that the first group of mark pulses will be registered in the first storage chain 38 after amplification and clipping to uniform amplitude in preamplifier 31 and clipping amplifier 33. The output of amplifier 33 is applied to all the storage chains 38 but is gated into the relevant one only. The space pulses received between digits cause the steering circuit 37 to route successive digits to the corresponding storage chains 38, In addition, the elapsed time-of-call pulses are also routed to the cost computer 39, which having already been signalled the destination of the call by the printing control circuit 35, assesses the charge to be made. The ground on the destination lead 8a informs the printing control circuit 35 of the number of groups of pulses which must be received for a successful call. Consequently, when the end-ofcall signal is received, if less than this number of groups of pulses have been received, the printing control circuit 35 immediately clears the storage chains 38 and the cost computer 39, restores the steering circuit 37 to normal, and recloses the operating circuit for the clutch magnet to initiate a new playback operation. If, however, the correct number of groups has been received, the receipt of the end-of-call signal rauses the printing control circuit to deenergize the clutch magnet, and to initiate operation of a sequence switch which sequentially scans the storage chains 38 and the storage chains of the cost computer 39, and transfers the information registered therein into permutation code form which is used to control the permutation magnets of the printer 36. Each time a storage chain is read, the permutation magnets of the printer are energized in accordance with the information stored therein, following which the printer prints the corresponding character and the sequence switch steps on to the next chain. After all the information pertaining to one call has been printed, the sequence switch is stepped to its home position, and the storage chains 38, cost computer 39, and steering circuit 37 are reset to normal. The printing control circuit 35 then re-operates the clutch magnet to initiate a new playback operation. After the tape has been cleared of all the recorded information, it is driven forward until the start position is again reached, whereupon closure of the start position contacts in the recorder causes the printing control circuit 35 to maintain the clutch magnet energized to drive the tape forward for a distance sufficient to permit recording of the date and time information of a call. The printing control circuit 35 then deenergizes the clutch magnet, release