Patent GB-712508-A (GB)
Title: Automatic toll ticketing telephone systems
IPC: H04M15/04
Filed: 1952-02-18
Abstract: 712,508. Automatic exchange systems. AUTOMATIC ELECTRIC LABORATORIES, Inc. Feb. 18, 1952 [March 28, 1951], No. 4284/52. Class 40 (4) fhe class of a calling line is signalled to a register sender from the line-finder-primary selector link associated with the calling line, the link marking a pair of conductors according to the class of the calling line. The invention is applied to the system described in Specification 692,999 and also includes the following features (1) while calls to 7-digit directory number subscribers are treated wholly automatically, calls to 8-digit numbers are directed automatically to an operator who completes the call manually (2) to economize in the number of translating relays, calls involving the same routing digits but different charges are dealt with by the same translating relay, the charges being controlled by additional rate relays. In this Specification the term "director" is synonymous with "register sender." Classes of calling line.-The subscriber's lines are divided into three groups A, B, C, served by groups of line-finder and primary selector links 440A, 500A, 440B, 500B, and 440C, 500C, respectively. Group A comprises metropolitan business lines of class 1 type, metropolitan residence lines of class 2 type and five-party lines of class 3 type. Group B comprises flat rate business and residence lines of classes 5 and 6 type. Group C comprises call boxes of class 4 type. Some of the classes are sub-divided into restricted and non- restricted subscribers. Initiation of a call.-When the class 3 non- restricted subscriber at substation 401-NRC3, Fig. 5, closes his loop, the line circuit 405B, distributer 442A, and line finder 440A function in the manner described in Specification 692,999 to operate the line relay R530 in the associated primary selector 500A. R530 energizes hold relay R540 and transfer relay R550 to cause the director hunter 450A to hunt for and seize an idle director, at which time the director test relay R510 pulls up and marks the director busy. R510 also transfers the conductors C444A, C445A from the circuit of the line relay R530 to a circuit including conductors C471, C472 extending to the coder 1100 in the director, line relay R1130 and test relay R1120 in the coder operating over the calling loop. Meanwhile relays R530, R540, R550 in the primary selector restore to normal. R1130 energizes hold relay R1140 and grounds conductor C1145 for control of the primary selector if the first two digits dialled indicate that the call is local. Hold relay R1140 operates seizure relay R750 in the controller portion 600 of the director, starts the timer 1190, restores R1120 and connects direct ground to conductor C472 to improve the loop circuit for impulsing. Registration of class of calling line.-R750  prepares the sender switch' 1660, the receive sequence switch 1510 and call recorder 2000 all of which function in known manner. R750 also causes the operation of test relay R510 and relay R820, the latter energizing class test relay R720, which connects conductor C470 to the class 2 and 5 test relay R670 and conductor C469 to the class 4, 5 and 6 test relay R600. R720 also energizes control relay R730 slowly, R730 then releasing R720 slowly to connect conductor C470 to the class 3 and 6 test relay R710. In the example, the primary selector serving the class 3 subscriber 401- NRC3 applies resistance battery over terminals T13, T17, Fig. 5, to conductor C470 to energize relay R710 only among the class test relays. More generally, and as more particularly described below under the heading "Class grouping of calling lines," according to the class of calling line served, so terminals T11, T13, T17, T20, T24, Figs. 4 and 5, may be interconnected in various ways to indicate the six classes of service by ground, resistance battery or lack of potential on conductors C470, C469, to operate none, one or two of relays . R600, R670, R710 in the director. Slow release of R720 and R730 disconnects conductor C469 from R600 and energizes class control relay R760 which causes one of lamps 676, 677, 678, to light up to indicate that the calling line is class 1, 2 or 3 or one of these lamps to flash if the line is class 4, 5 or 6. If the call requires a translator, assigner test relay R650 operates to energize relay R1340A, R1350A or R1360A, according to whether the line is'class 1-3, 5 or 6, or 4. Relays R600, R670, R710 also mark WXYZ 8, conductors Fig. 19 (not shown) to indicate the class of line to the call recorder 2000. Operation of class control relay R760 connects dialling tone to the calling line. Registration of dialled digits.-Line relay R1130 responds to dialled digits in the manner described in Specifiication 692,999 to register the seven digits of a normal directory number in the call register 1500, and translator code switch 1200 (not shown) is operated in known manner according to the first three digits. Party lines.-The dial mechanism of partyline subscribers TS1-3 to TS5-3, Fig. 4, is of known type except for the provision of five parties to the line. Party test relay R1150 and associated mechanism in the coder 1100 and recorder 2000 function in the manner described in Specification 692,999. Restricted subscribers.-By connecting contacts 1 and 2 of wiper 1546 of the third code register switch 1540 to terminal block TB1528 and by connecting the trunklines to the Florida 1 and Florida 2 exchanges to the first and second levels of primary selector 500A, non-restricted subscribers such as 401- NRC3 in the Florida 3 exchange can make calls to subscribers in the other two exchanges, the director releasing as soon as it realises that it is a call within the same zone. A restricted subscriber such as 401-RC3, however, is not permitted to make such as call. This subscriber is served by line circuit 405A and line finder 440A closes its left normal post-springs LNP491A whenever it establishes contact with this line circuit. Also whenever the wipers of primary selector 500A are raised to the levels terminating trunks to the Florida 1 or Florida 2 exchanges, left normal post-springs LNP578 are also closed. Thus, if the restricted subscriber attempts to call either exchange, the director releases as described above and the wipers of the primary selector hunt over the selected level for an idle trunk. However, as LNP491A and'LNP578 are closed, the upper winding of switch-through relay R520 is shunted and the rotary relay R560 is continually reoperated until the wipers reach the 11th rotary step position to open contacts CAM557, so releasing the rotary relay. Contacts CAM558 close and CAM559 open to apply busy tone to the lower winding of line relay R530. If a subscriber attempts a toll call from which he is barred, he receives busy tone in a similar manner. Calls to exchanges outside the originating exchange zone.-In the manner described in Specification 692,999, the dialling of the third digit operates assigner start relay R640, which causes the translator assigner 1000, Fig. 10 (not shown), to hunt for the calling director, and to seize the translator 1300. Assigner test relay R650 then pulls up to apply ground to the conductors C681-C683, depending on the class group A, B, or C, of calling line, to operate the corresponding class group relay R1340A, R1350A or R1360A, equivalent to the class relays in Specification 692,999. In the manner described in the prior Specification, the translator is assigned to the exclusive use of a calling director for a very short time, during which the information stored on the contacts of a selected translator relay such as R1410A is transferred to and registered in the coder 1800. The coder then controls the director to dismiss the translator. Class grouping of subscribers' lines.-As set out above under the heading "Registration of class of calling line," terminals T10, T11, T13, T17, T20, T24 in the primary selectors may be strapped in various combinations to provide marking potentials on conductors C502, C503 connected to conductors C470, C469 to register the class in the director, and the example of class 3 lines connected to finder-selector links 440A, 500A, was given. In Fig. 4, a group of finder-selector links 440C, 500C may serve three different classes 1, 2 and 3 .  namely substations 401-Cl, 401-C2 and party lines TS1-3 to TS5-3. Links 440B, 500B, may also serve three classes 4, 5 and 6; namely substations 401-C4, 401-C5, 401-C6. The links of Fig. 4 differ from links 440A, 500A in that they have additionally right normal post-springs RNP492B, RNP492C, which close when the selectors are serving class 6 and class 3 substations, respectively. No post-springs close for classes 1 and 4, while LNP491C or LNP491B closes for class 2 or 5, respectively. Eight-digit calls.-The system is entirely automatic for calls to substations with 7- digit directory numbers and semi-automatic for 8-digit numbers. In a call to an exchange provided with both 7 and 8-digit numbers, the registration of the code digits causes the selection of a route relay such as R1410A which energizes HM relay R1880 as well as performing its normal functions. For 7-digit calls, the apparatus operates in the manner already known. If however, an eight digit is dialled, the partially established connection is released and a new connection is made by the director over an alternative route to the "0" operator in the originating exchange. When the seventh digit is registered in the fourth numerical register 1640, the wipers of the receive sequence switch 1510 are automatically advanced to eighth position, wiper 1515 energizing the 4th numerical send relay R990 (not shown). HM relay R1880 grounds wiper 1516 of the receive sequence switch to energize magnet RM1511 over an alternative self-interrupting circuit to advance switch 1510 one step. If now the calling subscriber dials an eighth digit, magnet RM1511 is operated over the usual circuit and the first groun