US2402700A - Telephone system - Google Patents

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Publication number
US2402700A
US2402700A US336494A US33649440A US2402700A US 2402700 A US2402700 A US 2402700A US 336494 A US336494 A US 336494A US 33649440 A US33649440 A US 33649440A US 2402700 A US2402700 A US 2402700A
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Prior art keywords
relay
contacts
line
circuit
conductor
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US336494A
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Samuel B Williams
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AT&T Corp
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Bell Telephone Laboratories Inc
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M15/00—Arrangements for metering, time-control or time indication ; Metering, charging or billing arrangements for voice wireline or wireless communications, e.g. VoIP
    • H04M15/04—Recording calls, or communications in printed, perforated or other permanent form

Definitions

  • This invention relate to measured service telephone systems in which a permanent record is made of the calling line identification and the charge units assessed for a connection between a calling line and a called line and in which the chargeunits ,are designated by one, or. more impulses depending upon the destination of the completed connection or the number of time intervals consumed after the connection is established.
  • the object of 'the'invention i to improve such systems by providing a recording mechanism available to said lines by which the number or otherdesignation of the calling line and the numberofcharge units to assessed for a call there'- irom rare permanen-tlyirecorded. I'm-has been ,iound desirable, ⁇ for instance, and particularly in multiofilce and suburban telephone systems. to provide two or more classes of service.
  • the subscribers stations maybe classified asresidence stations and busi- .ness stations and the area itself divided into a plurality ofzones. With such a classification, the residence subscribers will be v iven unlimited flat rate service for calls to stations within the same zone-and will be charged one or more charge units ,Ior each call to stations in any of the other zones.
  • the business, subscribers on the other hand, will be charged a rate of ,one charge unit for .each call to stations within the same zone but, in addition, will also be charged additional charge units for each call to stations in the other zones.
  • the. subscribers lines of a telephone system are divided into a plurality of zones all of which, in establishing connections, have access to line finder switches capable of discriminating between one or more classes of lines, and furnished "with a switch responsive to impulses that designate themumberof charge units-for a .call.
  • These impulses may, of course, be transmitted from a distant repeater which is adapted to produce a number of impulses indicative of a connection established thereover, or from a first selector adapted to produce a single impulse for ,a local call routed therethrough, or ,from a selector in a switching train wherein the call is metered purely on a time basis.
  • the line finder switches have access, in turn, to common recording facilities that are adapted to produce a permanent .identificationof the calling line terminal number or the directory number, whichever is desired, and of the number of charges registered y the line finder register switch.
  • Each aof these records may be produced on a tape or other continuous impressible media by perforators, light valve ap- ,paratus or similar devices well known to the art.
  • One feature of .the'invention isca line finder switch that'inc'ludes a register switch responsive to impulses from a trunk in the switching train, the circuit of said register switch including responsive means that indicate which of two parties of a two-party line is calling.
  • Another feature of the invention is a recordin circuit accessible to all line finder groups which is provided with a novel means Lfor identifying the calling line.
  • Yet another feature of the invention is a register in said recording circuit which is used in common by the line identifiyng'means of the recording circuit and by the registering switch of the line finder to temporarily register. in succession, each of the digits of which the calling line numberis composed and of the digit that designates the number of charge'units registered in the stepping switch of the line finder taken into use, each ing therewith that translates the marked ter minal into the directory number of the calling line.
  • a further feature of the invention lies in a guard circuit that keeps a line finder out of serv ice after use in a connection until a charge for the call registered in the switch associated therewith is properly recorded by the recording circuit against the calling line notwithstanding the fact that said, calling line may have restored and released the line finder before a record of the charge has been made.
  • Fig. 1 shows two subscribers stations A and B, lines LI and L-Illfl, line circuits LC! and LC-I00, two sets of brushes and two sets of terminals of the bank of each of two line finder switches LFI and LF
  • Fig. 2 shows the vertical commutators 231 and the commutator brushes 238 of the line finders LF[ and LF-l I, resistors 22! to 225, inclusive (a set for each of the line finders) and a linemé control unit LFC-B;
  • Fig. 3 shows the circuit of the line finder switch LFI including the charging register 330;
  • Fig. 4 shows a line finder control unit LFC-A
  • Fig. 5 shows a first selector switch S permanently associated with the line finder LF-I of Fig. 3, a timing circuit TC, a repeater R, two other selectors S2 and S3 shown in schematic fashion, two connectors C4 and C3 accessible, respectively, from selectors S2 and S3; subscribers stations AS! and AS2, a part of the recording circuit and parts of the line finder switch LF
  • Fig. 7 shows the common register and perforator of the recorder circuit; while Fig. 8 shows the manner in which Figs. 1 to '7,
  • the subscribers stations are of the usual type employed in common battery automatic telephone systems and each includes a dial or other impulse sending device for controlling the numerical switches through which connections with other subscribers lines are established.
  • the line circuit LC-l comprises a combined line and cutoff relay Ill and a permanent signal lock-out relay I M.
  • the line circuit LC--l comprises similar relays Ill and ll4'.
  • and LF-H, selector switches S, S2 and S3, and connectors Cl, C2, C3 and C4 are of the well-known twomotion' step-b-y-step type. A clear and complete description of the structure of such switches is to be found in Automatic Telephony by Smith and Campbell, 2nd edition, pages 53 to 67., inclusive.
  • the bank of each of the line finder switches is represented in the drawing by two sets of terminals and the banks of the selector and connector switches are each represented by a single set of terminals,
  • the line finder LF-l and selector S are shown but the line finder LFH, selector switches S2 and S3, and connector switches CI to C4, inclusive, are represented by the brushes and the one or two sets of terminals.
  • the line finder circuit as
  • the brush shaft (not shown) of this switch is equipped with a pair of normal post springs 324 which can be adjusted to operate when the shaft has stepped vertically to any one of the ten horizontal levels of terminals reserved to the subscriber lines.
  • discrimination may be made, say, between a group of lines which is entitled to fiat rate service and another group entitled to individual message rate service.
  • the trunk (that is, the combination of the line finder and first selector S) comprises a pair of charging relays 305 and 306 controlled by the polarized relay 30'!
  • relay 304 controls the operation of the relays 305 and 306 when relay 304 is not operated, to record the charges on said switch.
  • the operation of the relays 305 and 306 when relay 304 is not operated, is controlled from the interrupter circuit 325 and results in the count of one on the charging switch 330.
  • each line finder switch LFl Associated with each line finder switch LFl are two stepping switches of known structure, namely, switches 520 and 530. As the line finder brushes are raised vertically and turned horizontally, the switch 520 is operated each time the vertical magnet 343 of the line finder is operated and switch 530 is operated each time the horizontal magnet 344 is operated.
  • the operation is synchronized by the back contacts of stepping magnets 532 and 533 of switches 520 and 530, respectively, which are in parallel with the back contacts of the vertical and rotary magnets 343 and 344, respectively, of the line finder,
  • the number of vertical steps taken by the line finder is registered on switch 520
  • the number of rotary steps taken is registered on switch 530
  • the particular set of terminals belonging to the calling line is determined by the operation or non-operation of'relay 342 and registered on relay 3l2 of the trunk.
  • the identification circuit shown in Fig. 6 and the recording circuit shown in Fig. 7 are adapted to be connected to a calling line finder when ground is connected by said finder to conductor 3 l8.
  • a relay SM is provided for each trunk and this, together with relay 602, provides for noninterference in case two trunks are calling for the recording circuit at the same time.
  • a relay 603 is provided for each group of trunks serving the same line finder group. These relays 603 together with relay S04 provide for non-interference between line finder groups.
  • the common identification and recording circuit can be connected to one trunk at a time. When so connected, one of the relays 605, 606 or 601 is operated depending upon whether or not relay 3li2 in the line finder is operated, to distinguish between the upper and lower terminal sets at the brushes of the line finder switch.
  • the positions assumed by the switches 520 and 530, respectively, indicate the terminal identity of the calling line on the line finder terminal bank, and circuits completed over the terminal arc of each of these switches result in the opera tion of a vertical and horizontal magnet of the cross-bar switch 650 which is effective in closing a cross-point on the switch that includes a grounded conductor that marks the calling line.
  • the cross-bar switch shown is assumed to be a six-wire switch, thus providing for six hundred terminals, one for each line of three line finder groups of two hundred lines each.
  • the vertical rows on the switch represent line finder level positions while the horizontal rows represent the line finder terminal positions.
  • the cross-bar switch 650 is of the type disclosed in Patent 2,021,329, issued to J. N.
  • the marking conductors from the various cross-points of the switch 650 which indicate the terminal numbers of the lines on the banks of the line finder frame, extend to the distributing frame 550 where, by cross-connection to the line terminal frame 560,.
  • the line finder terminal number may be translated into a line directory number through the operation of a translating circuit which consists of four relays 52452'I and a relay 62I per group of twenty-five lines, and a group of twenty-five relays 625-4549 for the entire office.
  • the contacts on relay 62! and the relays 625-549 provide for the tens and units digit designations while other contacts on relay 62I alone provide for the thousands and hundreds digit designations as will be subsequently set forth.
  • the recording circuit shown in Fig. 7 includes a perforator III! which comprises a punching magnet H8 and five recording magnets I5, six pairs of progress-relays lIlII02 'II3'II4, and a register comprising ten relays BO-J39 and relay I4I.
  • Each pair of progress relays is operated for the registration of a particular digit of the directory number and, also, for the digit which represents the number of charge units for the call.
  • the lower of the two progress relays connects the register with a group of ten conductors extending between each of the first four pairs of progress relays IIlI--Ill8 and the line translating circuit.
  • the progress relays I09 and III When making the record of the number of charge units, the progress relays I09 and III connect the register relays with the group of conductors which extend to the terminals of the charging switch 330, and the particular conductor grounded by the brush 3I3 will cause the operation of a register relay whose connection with the perforator will result in the punching of the digit that corresponds to the terminal to which brush 3
  • the repeater R to which the selector S may have access is of a conventional design W811 known to the telephone art and comprises a group of relays which, upon response of the called subscriber ASE, operate to produce a number of pulses which are transmitted over conductor 3I'I to effect the operation of the magnet 3 I U of charging switch 330.
  • the number of pulses produced by the repeater indicates the number of charge units to be assessed for a call routed thereover and it iseasily seen that the number of impulses may be different with groups of repeaters that give access to different zones for which the charges are different. Provision is made to cancel one of the charge units in the repeater on signal from the line finder normal post springs 324 that the call is from a line entitled to flat rate service, in which event, since the. subscriber is entitled to one charge unit for the call, the same must be subtracted from the total charge units assesse for a call routed through the repeater.
  • the selector S has access, of course, to second selectors such as S2, for example, in which no impulse producing facilities are required. This selector gives access to a'local zone where one charge is provided upon the reversal of the loop on the response of the called line. There are other selectors to which selector S has access which are designed to time the call for charging on a telechron unit basis. These types of selectors as well as the manner of charge control exercised thereby are so well known in the art that their conventional representation as shown in Fig.
  • relay I II contacts and left winding of relay I II to ground.
  • the right winding of relay I I I has a high resistance and, therefore, said relay is only partially energized by the current in this circuit.
  • Relay III closes its No. 6 contacts thereby connecting ground to conductor finders of both subgroups. (Ground is permanently connected to the top commutator segment of each line finder so that a finder will always stop on the top level, if notbefore.)
  • the ground connected to conductor H2 is further extended through resistor 22I (which is common to the twenty lines connected to the first level of the finders in subgroup A) to start conductor 220.
  • relay 451 is held operatedv in a circuit which includes the No. 1 contacts of relay 459, left contact of make-busy key 459, upper contacts of the make-busy key MB of each finder in subgroup A, upper back contact of the vertical off-normal springs 345 of each idle finder in the subgroup, thence over conductors 346, through the No. 2 back contacts of relay 5IlI, back contacts of relay 500, and No. Shack contacts of relay 502 of each associated idle first selector, to ground, Assuming that there is anidle finder in subgroup A so that relay 451 is operated, the connection of ground to conductor 220 causes the operation of start relay 450 over the No. 2 front contacts of relay 451, winding of relay 450 to battery.
  • Relay 450 in operating, connects ground over its No. 2 contacts'to' conductor 454 to start the ringing interrupter 463, and connects ground over its No. 1 contacts to conductor 462 leading to the alarm circuit 460 for the purpose of effectingan alarm in case relay 450 remains unduly operated.
  • Relay 450 further closes a circuit for operating relay 45I which extends from battery through the winding of relay 45!, No. 4 contacts of relay 454, No. 5 contacts of relay 453, No. 4 contacts of relay 450, to ground at No. 4 back contacts of relay 459; Relay 45I look through its N0, 6 contacts under the control of relays 454 and 459 and closes a. circuit for operating. the-line relay of the selector associated with the allotted line finder.
  • the brushes 4' to 416 of the line finder allotter switch are in engagement with the first set of terminals, which terminals are connected to the line finder whose circuit isshown in Fig. 3.
  • the circuit closed by relay 45! for operating the line relay 500 of the associated selector S of Fig. 5 is traced from ground through resistor 458, No. 4 contacts of relay 45l, No. 6 contacts of relay 454, through brush 415 and terminal I, conductors 348 and 333, No. 3 back contacts of relay 5132 of selector S, through the upper winding of relay 500 to battery.
  • relay 500 closes a circuit for operating the slow-to-release relay 50L Rela 5M connects the lower winding of relay 533 through its No. l contactsto conductor 534 which extends to ground in the permanent signal timing circuit TC and connects ground through its No, 4 contacts to the winding of relay 502 and the No. 1
  • Relay 503 operates, locks through its'upper winding and the No. 3 contacts of relay 5M, and connects conductor 300 to conductor 505 via its No. 1 contacts to ground in the timing circuit TC.
  • Relay 45! connects ground through its No. 1 contacts to hold relay 451 operated during the operation of the allotted finder to find the calling line in case this line finder is the only available one in the group.
  • Relay 45l also closes a circuit for operating the stepping relay 452 which extends from battery through the lower winding of said relay, No. 3 contactsof relay 45!, brush. and terminal! of bank 414 of the allotter switch, back contact of the 11th rotary step springs 322, No. 2 back contacts of relay 342, No. 2 back contact of relay 34] the back.
  • the stepping relay 452v operates and closesa cire cuit from ground at the No, 3 back contacts of relay 454, front contacts of relay 452,.No. 1 back contacts of relay 453, brush andv terminal i of bank 413 of the allotter switch through the winding of the vertical stepping magnet 343 to battery.
  • Magnet 343 operates, stepping the brushes of the finder up to the first level.
  • the vertical oilnormalsprings 345 are actuated when the shaft on which the brushes are mounted moves out of normal position.
  • magnet 343- opens the operating circuit of relay 452, but if the calling line is connected to terminals in the first level of the line finder bank, relay 452 is held operated to prevent reoperation of magnet 343.
  • the circuit for holding relay 452 operated is trace from battery through the lower winding of said relay, No. 3 and No. 2 contacts of relay 45
  • relay 452' The described cycle of operations between relay 452 and magnet 343 is repeated to raise the brushes step by step until the brushes of the finder reach the level of th terminals of the calling line, at which time relay 452 is held in the circuit through commutator brush 238 as already described.
  • the winding of magnet 532 of rotary stepping switch 520 In parallel with the winding of vertical magnet 343 is the winding of magnet 532 of rotary stepping switch 520 whose terminal arc comprises ten terminals and a normal terminal N with which the brush 52I of the switch is in normal engagement.
  • the ten terminals are multipled to conductors which extend to the windings of the ten select magnets 6
  • the winding of magnet 533 of rotary stepping switch 530 In parallel with the winding of rotary magnet 344 is the winding of magnet 533 of rotary stepping switch 530 whose terminal arc comprises ten terminals and a normal terminal N with which the brush 523 of the switch is in normal engagement.
  • the ten terminals are multipled to conductors which extend to the windings of the ten hold magnets 660-669 of the cross-bar switch 650 in the same order as the numerical designation of each of the terminals; that is, the conductor connected with terminal being connected to the conductor which extends to the winding of hold magnet 660 and so on up to and including the conductor connected with terminal 9 which extends to hold magnet 669.
  • the non-inductive resistor 461 connected across the upper winding of relay 452 makes this relay somewhat slow in releasing so as to prevent its release if the brushes are momentarily advanced beyond the terminals of the calling line; it also prevents the release of relay 452 while the current is building up in the circuit through the test brush and terminal of the calling line.
  • the current in this circuit is effective to complete the operation of relay III and to energize the lower winding of relay 34I and thereby partially operating said relay to the extent of closing its No. 3 contacts and completing a circuit from battery through said upper winding and No. 3 contacts, No. '7 contacts of relay 342, to ground on conductor 300 as already traced thereto.
  • relay 34I With relay 34I completely operated by its upper winding, the line L-I is connected through brushes I3I and I32, the Nos. 1 and 7 contacts, respectively, of relay 34I, upper and lower windings of polarized relay 30l, conductors 302 and 303, Nos. 2 and 3 back contacts of relay 502, to the windings of the line relay 500 of selector S.
  • the complete operation of relays 34I also disconnects the lower winding of relay 342 from conductor 439, disconnects the release magnet 349 from conductor 346, disconnects the lower winding of relay 452 from the contacts of magnets 343 and 344, and closes a circuit for holding relay 452 and operating relay 454. This circuit is traced from battery through the lower windin of relay 452, No.
  • relay 45I the complete operation of the line and cutoff relay III through its middle winding is assured by its connection through conductor H6, terminal H9, brush I33, contacts of magnet 349, Nos. 4 and 3 contacts of relay 34I, No. 7 back contact of relay 342, conductor 300 to holding ground potential already connected to this conductor as above described.
  • Relay 452 is held operated by its upper winding and relay 342 is partially operated by its lower winding. Relay 342 closes its No. 4 front contact thereby completing a circuit through its upper winding to ground on conductor 300. Relay 342 is thereby completely operated, connecting the calling line to selector S.
  • Relay 342 also disconnects the lower winding of relay 34I from conductor 439 and disconnects the locking contact of relay 34I from conductor 300 so that, if relay 34I ha also operated due to brushe I3I, I32 and I33 engaging the terminals of a calling line, relay 34I will release and the line engaged by brushes I34, I35 and I36 will be the only one connected to selector S.
  • Relay 342 also disconnects the winding of release magnet 349 from conductor 346, discon- 11 nects the lower winding of relay 452 from the contacts of magnets 343 and 344, and closes a circuit for holding rela 452' and for operating relay 454. This circuit i traced from battery through the lower winding of relay 452, No.
  • Relay 342 also connects the test brush I36 directly to conductor 300 to insure the com plete operation of the line and cut-oil relay of the calling line and completes an obvious circuit for relay 3l2 which operates and locks to ground on conductor 5H3.
  • relay 454 With relay 454 operated, due either to the operation of relay 34
  • relay 454 disconnects ground from the contact of the stepping relay 452 to prevent further operation of the rotary stepping magnet 344; opens the circuit path through brush 415 and conductor 348 to the upper winding of the line relay 500 of selector S; opens the circuit through the upper winding of relay 452 and brush 412- of the allotter switch, and causes the release of relay 45!.
  • relay 451 opens the circuit through the lower winding of relay 452, brush 414 and the upper winding of relay 454, thereby causing the release of relay 452.
  • the release of relay 451 also opens the circuit for holding relay 451 operated which, however, will not release if there is an idle line finder supplying ground over conductor 346 through the left contacts of key 469, and causes the release of relay 453.
  • relay 453 closes a circuit for operating the stepping magnet 410 of the allotter switch that extends from battery through the winding and interrupter contact of said stepping magnet, No. 2 contacts of relay 454, No. 4 contacts of relay 453 to ground on the No. 1 front contacts of relay 451.
  • the operation and release of magnet 410 steps the brushes of the allotter switch to the next set of terminals.
  • Relay 500 completes a circuit for relay 50! extending from battery through the winding ofsaid relay, front contacts of relay 500, No. 5 contacts of relay 502 to ground.
  • Relay 50-I operates and, among other functions; applies ground to its No. '4 contacts which, through the No. 1 normally made contacts of relay 503, is applied to conductor 300.
  • Dial tone is transmitted to the calling subscriber in the usual, manner and, when the subscriber dials the first digit of the called subscribers number, relay 500 is alternately released and reoperated by each of the impulses in the train.
  • Therelease of relay 500 in response to the impulse, closes a circuit from battery through the winding of the vertical stepping magnet 506, winding of change-over relay 509, No. 2 front contacts of relay 50I, through back contacts of relay 500, No. 5 back contacts of relay 502 to ground.
  • the operation of magnet 506 raises the brushes 5, 5l2, 5l3 and 5M to the first level of the bank.
  • This circuit includes the upper set of contacts of springs 5l5, the front contact of relay 509 and the No. 4 contacts of relay 50L Relay 5l0 locks in a circuit which includes the contacts of the rotary stepping magnet 501, the N0. 2 contacts of relay M0, the No. 5 contacts of relay 502 to ground.
  • relay 500 reoperates at the end of the first impulse, the vertical stepping magnet 506 releases.
  • Relay 50I is slow in releasing and remains operated while relay 500 is responding to dial impulses.
  • Relay 509 is also slow in releasing and remains operated until all of the impulses in the series have been received by relay 500.
  • the vertical stepping magnet 506 is reoperated by the release of relay 500 in response to each ofthe succeeding impulses of the train, thereby stepping the brushes up to the level corresponding-to the digit dialed.
  • the first digit dialed by the subscriber may act to discriminate between an unlimited service area and one in which the charge for the call is a function of its destination.
  • a set of normal post springs 529 is provided in the first selector which may be adjusted to close at any desired level. If, for instance, multiple charging is reserved. for trunk outlets located on the fifth level and over the terminal banks accessible to brushes 5
  • relay 509 When relay 509 releases after the last impulse of the train has been received (assuming that the switch S has been advanced to the fifth or higher terminal level), it closes a circuit from battery through the winding of the rotary stepping magnet 501, No. 1 contacts of relay 510, back contacts of relay 509 to ground at the No. 4 contacts of relay 501.
  • the operation of magnet 501 advances the brushes into engagement with the first set of the terminals in the selected level and it also causes the release of relay 510 which, in turn, causes the release of magnet 501.
  • test brush 513 encounters a ground potential thereon which is effective to cause the reoperation of relay 510 over a path that extends from battery to the winding of said relay, the upper contacts of springs 515, contacts of magnet 501, lower back contact of the 11th rotary step springs 516, the No. 4 back contacts of relay 502, brush 513 to the ground potential (not shown) on the sleeve terminal of the busy repeater.
  • Relay 510 recloses the circuit for operating the rotary stepping magnet 501 and the brushes are thereby advanced to the next set of terminals.
  • Relay 510 and magnet 501 in operating and releasin in the manner described, thus cooperate to advance the brushes of the selector step by step until an idle set of terminals is encountered as determined by the absence of ground on the test terminal of the set engaged by brush 513, whereupon relay 502 is operated in a circuit traced from battery through the winding of relay 510, upper set of contacts of springs 515, contacts of magnet 501, lower back contacts of the 11th rotary step springs 516, winding of relay 502 to ground on the No. 4 contacts of relay 501.
  • Relay 502 operates in this circuit but relay 510, being marginal, does not.
  • Relay 502 operates and disconnects the windings of relay 500 from conductors 302 and 303 and connects these conductors through its Nos. 2 and 3 front contacts, respectively, and brushes 511 and 512, respectively, to the terminals of the selected repeater.
  • the release of relay 500 causes, in turn, the release of relay 501 which, in turn, causes the release of relay 503.
  • Ground is momentarily extended from the No. 4 contacts of relay 501 through the No. 4 front contacts of relay 502 and brush 513 to the test terminal of the selected set of terminals to mark the trunk connected thereto busy until holding ground potential is connected to the test ter minal thereof in the usual manner.
  • the impulses produced by the dialing of the succeeding digits of the called subscribers number effect the operation of the outgoing trunk repeater R associated with an interofiice trunk over which the desired connection may be completed and which determines not only the route of the call but also the number of charges to be madetherefor.
  • the line relay 551 of said repeater is operated, the operating circuit being traced from battery through the upper winding of relay 51!, No. 3 normal contactsof reversing relay 553, through brush 512 of selector S, No. 3 front contacts of relay 502, conductor 303, lower winding of polarized relay 301, No. '7 ,contacts of relay 341, brush 132 and terminal, subscribers loop, brush 131 and terminal, No.
  • relay 551 closes a circuit for operating relay 552 and relay 552 connects ground over conductor 510 and to the sleeve terminal of the repeater to:hold the first selector switch S in usual manner and to hold relay 502 operated.
  • the line relay 551 of'repeater R responds to the impulses produced by the dialing of the second and succeeding digits of the called number to repeat each train of impulses over trunk T, the first repeated train of impulses being effective to control the selective operation of the incoming-selector switch S3 and the last two repeated trains of impulses being effective to control the selective operation of the connector switch C3 to establish connection with the line leading to the called station AS2.
  • the called line is tested and, if idle, ringing current is transmitted thereover to operate the ringer at station AS2, all in the wellknown manner.
  • the removal of the receiver at station AS2 to answer the call causes th operation of the reversing relay 553 of repeater R in usual manner, thereby reversing the current through the windings of polarized relay 301 and causing said relay to operate and complete a circuit for relay 305 which extends from battery through the winding of said relay, No. 1 normal contacts of relay 306, contacts of relay 301, No. 1 normal contacts of relay 305, No. 2 front contacts of relay 304, conductor 300 to ground.
  • Relay 305 operates and closes a circuit for relay 306 which extends from ground through the No. 4 front contacts of relay 304, No. 3 contacts of relay 305, lower winding of relay 306 to battery.
  • Relay 306 operates, opens the circuit of relay 305 which thereupon releases, locks over its upper winding and No. 2 contacts to ground on conductor 300 and extend con- -15 ductor .3411 over its No. 4 -front contacts, .No. .5 front contacts of relay304, No.2 back contacts of relayv 32.3, winding of polarized :-.relay 301, No. 1 back contacts of relay 323, winding of slow-release relay 309, magnet 3110 of charging switch 330 :to ground.
  • the line finder circuit, over conductor'3 11, is now ready :to receive impulses indicating .intervals of chargeable :elapsed time for the connection or .the initial number .of charges 'for.
  • Theoperationof .relay 553. also closes .a circuit iromground through the front contacts of relay .552, conductor 51.0, .No. .4 contacts of relay 553, No. 2 normal contacts and winding of relay 536, conductor 561, .through the N o. 1 contacts of relay 539 to battery.
  • Relay 536 operates and looks over conductor 511, .No. 4 contacts of relay 539 to ground on conductor 5.10. From this point on, the operation of the repeater depends upon whether :ornot a signal has been received from the normal post springs 32.4 of the line finder that the calling line is entitled to fiat rate service. If such a signal has been received, then, as already described, relay:542 willhave been operated and locked. If .no signal has been received, indicating thereby that the calling line is entitled to individual message rateservice, then relay 542 will be normal.
  • Relay 536 in operating, closes .a circuit for operating relay 543 which extends from battery through the No. 2 contacts .of relay 539, conductor 568, the No. 1 contacts of relay 525, No. '1 contacts ofrelay 536, winding of relay 543 to ground.
  • Relay 3119 also operates in the above circuit.
  • relay 536 When relay 536 operated, it also closed a circuit for operating relay .525 :which extends from groundover conductor510, the No. .4 contacts of relay 539, conductor 5.11:1, the No. 3 contacts of relay 53.6, the .No. 2 normal contacts and winding of relay '525, conductor 561, the No. 1 5
  • Relay 525 in operating, opens the operating circuit for relay 543. Relay 543 accordingly releases, disconnects battery 558 from brush I51 4 and thereby :opens the circuit of magnet 1310 and that of relay 309. The magnet “releases "but relay .3119, being slow release, does not.
  • Relay 525 locks through its No. 2 contact over conductor 511 and, through :the No. 4 contacts of relay 539, to ground on nonductor51'0.
  • Relay 525 inoperating, alsocloses a circuitfor operating relay538 whichextendsirom battery through the No. 1 contacts of 'relay539, con'ductor 56'1, through the winding .and No.
  • Relay 538 in operating, locks to conductor 5 1 1 and closesa circuit for operating relay .528; this circuit including the No.2 contacts of relay 539, conductor .568, .No. 1 contacts of relay 531, .and the No. 1 contacts of relay 538, winding of relay 528 to ground.
  • Relay 528 in operating, reconnects battery 558 to brush 514 via the No. -2 front-contacts of relay 541 thereby again completing the charging circuit of magnet 310 which now cperates and advances brush 3.I3 another terminal.
  • Relay '538,.in operating also closes a circuit for operating relay 531; this circuit includes the No. 1 contacts of relay 539, conductor 561, the winding and No. 2 normal contacts of relay 531, the No. 3 contacts of relays 538, 525 and 536, conductor 511, and the No. 4 contacts of relay 539.
  • Relay 531 in operating, locks through its No. 2
  • Relay 531 in operating, also closes a circuit for operating relay 540 this circuit including conductor 561, the winding and No. 2 normal contacts of relay 546, the No. 3 contacts of relays 531,538, 525 and 536, conductor 511, No. 4 contacts of relay 539 to ground on conductor 510.
  • Relay 540 in operating, locks through its N0. 2 front contacts over conductors 5'11 and 5111, and closes a circuit for again operating relay 528; this circuit including conductor 568 and the No. 1 contacts-of relay 549.
  • Relay 528 in operating, reconnects battery '58 to brush 514 to cause the reoperation of magnet 310 andthe advancement of brush 313 to another terminal.
  • 'Relay549 also closes a circuit for operating relay 539 which is traced from battery through the winding and No. 3 normal contacts of relay 539, No. 3 contacts of relays 540, 53 1, 538, 525 and 536, over conductor I 511, the No. 4 contacts of relay539, to ground on conductor 5'10.
  • Relay 539 operates and locks through its No. 3 'frontcontact to ground on-conductor 510. The locking contacts of relay 539 close "before the operating circuit is opened.
  • relay 539 causes the release of relays 528, .525, .536, 53 1, 538 and 540.
  • the release of relay 528 disconnects battery 558 from brush 514 to cause the release of magnet 31!).
  • Each of the relays 525 and 536 to 5411, inclusive, is slow in operating to insure that the operation of relay 5'42 and each operation and release of relay 528 will effect a-corresponding operation and release of the charging switch 330,
  • the repeater R is equipped with overtime registering apparatu wherein overtime intervals for the connection are charged for at the rate of a definite number of charge units, say the same number which is initially charged when the connection is answered by the called subscriber
  • battery at the winding of relay 539 andthe Nos. 1 and 2 contacts thereof may be placed under the control of said registering apparatus which, operating at the beginning of the overtime interval, opens said battery to cause relay 539 to release. Since relay 552 would still be operated, then, when the battery is reconnected to the winding of relay 539 and the Nos. 1 and 2, contacts thereof by said registering apparatus, the repeater would then operate as before to'produce four charging pulses which are transmitted to the charging switch 330. The locked relay 539 is released again at the beginning of the next overtime interval and the operation is then repeated to produce another set of four pulses. Y
  • the polarized relay 301 is included in the circuit of the magnet 310 of the charging switch 330.
  • the first selector is provided with a relay 323 that,over a circuit (not shown), responds to this ground on the tip conductor and, upon so operating, reverses the 'direc tion of] current through polarized relay 301.
  • Relay 306 operates, locks over its upper winding and N0. 2 contacts to ground on conductor 300, and completes a charging circuit for relay magnet 310 which extends from battery through the No. 5.contacts of relay 306, No. 2 contacts of relay 305, No.5 back contacts of relay 304, No. 2 back contactsof relay 323, winding of relay 307, No. 1 back contacts of relay 323, winding of relay 309, winding of magnet 310 to ground. Magnet 310 operates to advance brush 313 one terminal to register the onechai'gefor the call.
  • relay306 When relay306 operates, the locking circuit of relay 305 is transferred to interrupter lead 316 via the No. 1 front contacts of relay 306,- No. 1 contacts of relay 1, No. 3 contacts of relay 305, No. fl back contacts of relay 304, to interrupter ground on conductor 316. When the ground is removed from conductor 316, relay 305 releases and the charging circuit is opened thereby causing the release of magnet 310. Y
  • connection of ground to conductor 318 causes the operation of relay 601 in a circuit that extends from ground on said conductor, lower ference in case twoor more trunksare simul which event a path is completed for relay 308 pulse and causing relay 309 to operate and hold between pulses.
  • relay 309 releases and ground is connected to conductor 313 via ground on conductor 519 from the lower contacts of ofi-normal springs 511, 518 of switches 520 and 530, contacts of relay 309, upper contacts oi'oiT-normal springs 319 of switch 330 'toconductor 318;
  • relay 304 In the event that the call is completed througha selector in a local zone for which but one charge is made for the call, relay 304 will not be operated and, upon the operation of relay 301 in response to a currentreversal consequent to the called line answering, relay 305 operates from a ground closure on conductor 315 of the interwinding of.-said relay, back contacts of relay 602' to battery. 7
  • relay 601 There is one relay 601 for each trunk and this, together with relay 602which is common to all relays60'1, provides for non-intertaneously calling for the recording circuit shown in Figs. 6 and 7.
  • relay 601 of anytrunk over a circuit identical to the one above .describedfsaid relay locks over its upper winding and No.
  • relay603 which extends from battery through the front contacts of relay 602, lower winding of relay 603, back contacts of relay 604 f to ground.
  • Relay 603 operates andlocksover its. upper winding and No. 4 ,front contacts, winding of relay 604 to ground, thereby'causing relay 60 1 to operate in said locking circuit. 7
  • One relay 603 is provided for each group of trunks that serve the' same line finder group. These relays, together with relay 604 provide for non-interference between line'finder group inasmuch as the operation of relay 604 in the locking circuit of anyone of the relays 603 cuts off the ground required to complete the circuit of any of the'remaining relays 603, thereby effectively locking out all other line iinder groups from access to the recording circuit once any particular trunk in a group is locked in with it;
  • relay 605 When relay 603 is operated, relay 605 operates in a circuit which is completed from ground rupter circuit 325 which is only shown schematically.
  • Relay 305 operates and locks under the control of the operated contacts of relay 301 and its ownNo. 1 contacts.
  • relay 605 Upon the operation of relay 605 a circuit is completed for relay 605' which is traced from battery through the winding of said relay, the No. 2 contacts of relay 605, No. 5 contacts of relay 603, No. 4 contacts of relay 60!, conductor 608, to ground on the No. 2 contacts of relay 3
  • relay 605 When relay 605 operates, ground on its No. 1 contacts is applied to conductor B09 and a circuit is thereupon completed over the No. 1 contacts of relay 603, No. 1 contacts of relay 601, conductor 6, brush 52
  • EflChCOIl'EZtCt of each contact pair in the crossbar switch is extended to a terminal in the distributing frame 559 there being, for the switch, six hundred terminals in all and these, inturn, are cross-connected to terminals in the line finder frame 5% in accordance with the directory number of the several lines as shortly to be described.
  • the cross-point representsa party line, such fact will be known from the operated hold magnet which has a group of additional sets of contacts reserved for this purpose.
  • relay 605 (or front contact if calling line is in the lower hank) Iback contacts of relay 605 to the vertical contact in cross-point 6i? thence over a conductor to the terminal of the distributing frame and over to a terminal on the line terminal frame 550.
  • the decoding of the line terminal number into the directory number of the line is accomplished through a group of four relays 524-52l and one relay til for each of twenty-five lines and one group of twenty-five relays 625649 for the whole ofiice which, in the case illustrated, is limited to six hundred lines although the decoding principle is workable for a ten thousand line oifice.
  • Each relay in the group of twenty-five relays 625649 is assigned to one of the numbersfrom zero to twenty-four with relay 625 assigned to zero and relay 649 to twenty-four, the remaining intermediate relays being assigned to corresponding intermediate numbers in consecutive numerical order.
  • Each relay in each group of four relays 524-521 is equipped with six sets of transfer springs, the back contacts of which are all commoned and connected to the winding of relay 62l associated with one particular group of four relays.
  • the transfer contacts are all connected to individual terminals on the line terminal frame 560, each of said terminals being reserved to one line in the group. Since a group of relays 524-521 and the associated relay 62! are intended to serve a group of twenty-five lines and only twenty-four transfer contacts are provided by the four relays 524-52
  • relays 625-4549 are to serve all groups of twenty-five lines, since they are common to the office, each of these relays is Wired to a front contact in a corresponding relay in each group of relays 524-521.
  • relays 524521 and relay 62! shown in Figs. 5 and 6, respectively are reserved to the first group of twenty-five lines of the office, namely, lines 000 to 024, inclusive, relay 625 is extended, through the No. 1 front contact of relay 62!, to the 000 terminal on frame 560; relay 626 (not shown) to the No. 6 front contact of relay 524 the transfer contact of which is connected to terminal of the frame 5611; relay 62! (not shown) to the No.
  • each of the other relays is connected to one of the remaining front contacts in the order indicated up to and including relay 649 which is connected to the No. 1 front contact of relay 521, the cooperating transfer spring of which is reserved to line No. 024 on line terminal frame 560.
  • the twenty-five relays (625-4549) are, of course, multiplied to corresponding contacts in each of the groups of four relays (ML-521) reserved to each of the other twentyfive line groups in the office whose transfer contacts are wired, in turn, to the line terminal frame 560.
  • relay 605 operates and grounds the conductor individual to the calling line from the front or back contacts of relay 605 (or 806 or 601') the cross-connection between the terminal on the distributing frame to which the individual conductor is connected and the terminal on the line terminal frame 560 which designates the desired number for directory listing purposes, the ground on the individual line conductor will be applied to one of the back contacts of one of the relays in the group of relays 524-521 involved which, in turn, will complete the circuit of the associated relay 62!.
  • relay 652 which extends to the Winding of each of the relays in the group of relays 524-521 associated with the particular relay 621 that operated, causing said relays to operate and close their respective transfer contacts to each of the relays in the group of twenty-five relays 62 5649, except relay 625.
  • the relay in this group which will be operated will depend, of course, upon which of the twenty-four terminals on frame 560 the individual line conductor is cross-connected, and the operation of relay 62! in any one group of twentyfive lines combined with the operation of a relay in the group of relays 625-649 will ground four conductors that will operate, in succession, four relays in the group of ten relays -139 in the register of Fig. 'I that will cause the punching of appropriate respective codes for the thousands, hundreds, tens and units designations of the directory number.
  • the manner in which this is achieved through relay 62! and relays 625-64i) is as follows:
  • Each relay 62! has as many lower contact pairs as will be required to give the thousands, hundreds, and tens and units designation, the last two in accordance with the particular relay in the group of relays 625649 that was operated from frame 560.
  • the object in decoding is to operate, in succession, one relay in the group of ten relays 130-139 for each of the digits of the number, depending upon the value of the digit itself.
  • the numerical designation of each of said relays lath-I39 is chosen to indicate each one of the ten digits with relay 130 indicating the first or zero digit and relay 139 indicating the last or ninth digit.
  • This group of relays is wired to the contacts of pairs of progress relays in Fig. '7 which, operating and releasing progressively in the manner to be hereinafter described, connect these relays to conductors which extend to the contacts of the relays 62! and/or those of the one relay in the group of relays 625649 which is operated.
  • each relay 62! represents twenty-five numbers. It is obvious, therefore, that each of said relays may be made to mark arbitrarily the particular thousands and hundreds digit which includes the group of twenty-five lines represented by the relay. Each of these digits may, of course, be anything from 0' to 9 for the thousands depending upon the maximum line number capacity.
  • a conductor is extended from one of a pair of contacts on said relay 62! to that terminal on block 142 which connects with the armature of that pair of con- 23; tacts on relay HM, the make contact. of.
  • each of the four relays 625 in each group of one hundredlines are wired to the armatures ofthe relaysBZB-MB in accordance with the above distributionoi numbers and when relay 62! operates, ground isapplied to two of the armatures oi the relay in the group of twenty-five relays 625-649twhich has been operated from the terminal of frame 568..
  • relay 130 will 0perate (through thecontacts of; relay to designate the tens zerov digit.
  • Line numbers from Iii-l 9; inclusive, havea 1 for. the tens digit; hence the make contact of'the No. 7 contact set of relay i2i is connected to corresponding armatures in each of. the relays 635-6Mwhose, make contacts onthe other-hand are all multipled and connected (connecting conductor omitted) to the N0. 1 terminal on block 12.!
  • relays 625-634 operate consecutively for each of the units digits 0-9, inclusive. Since relay 62
  • each cooperating make contact on each of said relays is connected to a different terminal on block 128; the cooperating make contact of relay 625 which operates for the line iillbeing connected toterminal 0 and thereby causing the operation of relay ltil'through the No. 12 contacts ofrelay: 1.0T as will be shown; the cooperating. make contact of relay 626which operates for. the. line. 01b, being. connected. to terminal! and; thereby. causing the. operation of; relay. 113i.
  • Relays 635-644 operate consecutively for each of the units digits 10-19. Since relay 621 (1) marks the group of twenty-five lines including these numbers, the make contact of the No. 4 contact sets is further connected to corresponding armatures of each of said relays 635-644 and the corresponding cooperating make contacts are each connected to terminals -9 respectively on block 128.
  • the last four relays 645-649 operate consecutively for each of the last four numbers of the group 20-24 involving units digits 0-4 inclusive.
  • the make contact of the No. contact set of relay 621 (1.) is connected to corresponding armatures in each of the relays 645649, inclusive, and their respective cooperating make contacts are each connected to terminals 0-4, inclusive, on block 128, resulting in the operation, aswill be shown, of relays 130-134, inclusive, to designate the respective units digits of the last four line numbers in the group of 00-24 lines.
  • the Nos, 4-8 contact sets of each of the separate relays 621 (2), 6:21 (3) and 621 (4) are connected to the various relays 625-649, inclusive, to ground terminals on blocks 121 and 128 to cause the operation of the appropriate relays 130-139 to indicate the tens and units digits.
  • relay 621 When, therefore, relay 621 operates, its No. 1 contacts are closed to extend ground on the No. 1 contacts of hold magnet 6 60 previously traced to a terminal on the line terminal frame 560 to the winding of some relay in the group of relays 625-649 causing said relay to operate.
  • the relay which is operated in the group is the one that marks the tens and units number of the calling line, and since the proper relay 621 is likewise operated to mark the thousands and hundreds, the identity of the calling line is ready for recording the same on tape.
  • the recording circuit shown in Fig. '1 comprises six pairs of progress relays 101-113, the recording relays 130-139, relay 141, and a perforator 110 of known construction having the five punch magnets I to 5 and a punch magnet 118. It is also provided with a relay 116 in the event that a plurality of recording circuits all use the same perforator.
  • a relay in the group of relays 625-649 is operated, as for instance, relay 625, a circuit is completed for relay 1111 which traces from battery through the winding of said relay, No. 1 contacts of relay 102, No. 1 contacts of relay 625. to ground.
  • Relay 101 operates and connects the windings of relays 130-139 to block 142.
  • the connecting wires to the magnets extend to the right contacts of relay 116 whence they extend to the terminal block 123.
  • another block 124 to which are connected the make contacts in each of the ten relays 130-139 that denote, according to the above code, the digit to be indicated by each of said relays.
  • relay 1311 marks the zero digit and when operated to cause the punch-- ing of said digit upon the tape must, according to the above code, produce the operation of punch magnets 3 and 4,
  • the relay is provided with two sets of contacts that extend to the block 124 from which they are cross-connected to conductors 3 and 4 on block 123 and are grounded when the relay operates.
  • relay 139 which marks the ninth digit should cause the operation of magnets 1 and 5.
  • it is provided with two contact sets, the makes of which extend to the terminals of block :124 from which they are cross-connected to conductors 1 and 5 on terminal block 123 to close partial circuits thereover for punch magnets 1 and 5 when the relay operates.
  • each of the intermediate relays is furnished with a number of contact sets appropriate to the respective digital value that each of the relays is to designate.
  • Relay 130 operates and closes a circuit for relay 116 extending from ground on the No. 1 contacts of relay 130, right winding of relay 116, contacts of relay 119 to battery.
  • Relay 116 operates and looks over its left winding and No. 4 front contact, winding of relay 119 to battery.
  • Relay 119 operates and disconnects battery from the operating winding of relay 116 and all other relays 116, if any, are
  • relays 116 provided for connecting the perforator with more than one recording circuit. If, however, but one recording circuit is to be used, relays 116 and may be omitted and the conductors extending between the make contacts of the relays 130-139 and 141 and the right armatures of relay 116 may then be directly connected to the armatures of relay 111 and thence to the windings of the perforator magnets.
  • relay 116 When relay 116 operates, a circuit is completed for rela 121 which extends from ground on the No. 1 contacts of relay 605, conductor 609, through the Nos. 2 and 5 contacts of relay 102, No. 1 normal contacts of relay 115, No. 1 contacts of relay 116, winding of relay 121 to battery.
  • Relay 121 operates and closes a circuit for slow-to-release relay 120 via the No. 1 back contacts of relay 122, which relay 120 operating, in turn operates relay

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  • Computer Networks & Wireless Communication (AREA)
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US336494A 1940-05-22 1940-05-22 Telephone system Expired - Lifetime US2402700A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2513112A (en) * 1944-07-19 1950-06-27 Shepherd Judson O'd Data recording system employing record controlled apparatus
US2599357A (en) * 1946-02-23 1952-06-03 Bell Telephone Labor Inc Automatic telephone billing system
US2619545A (en) * 1947-06-13 1952-11-25 Bell Telephone Labor Inc Telephone calling line identification and recording system
US2621256A (en) * 1949-07-08 1952-12-09 Automatic Elect Lab Calling line identification apparatus
US2698879A (en) * 1943-05-05 1955-01-04 American Telephone & Telegraph Class of service determining circuit
US2956127A (en) * 1954-12-08 1960-10-11 North Electric Co Automatic telephone system
US3189687A (en) * 1962-02-02 1965-06-15 Charles G Miller Telephone switching system

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2698879A (en) * 1943-05-05 1955-01-04 American Telephone & Telegraph Class of service determining circuit
US2513112A (en) * 1944-07-19 1950-06-27 Shepherd Judson O'd Data recording system employing record controlled apparatus
US2599357A (en) * 1946-02-23 1952-06-03 Bell Telephone Labor Inc Automatic telephone billing system
US2619545A (en) * 1947-06-13 1952-11-25 Bell Telephone Labor Inc Telephone calling line identification and recording system
US2621256A (en) * 1949-07-08 1952-12-09 Automatic Elect Lab Calling line identification apparatus
US2956127A (en) * 1954-12-08 1960-10-11 North Electric Co Automatic telephone system
US3189687A (en) * 1962-02-02 1965-06-15 Charles G Miller Telephone switching system

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