US1842602A - Automatic telephone system - Google Patents

Description

Jan. 26, 1932. F. GoHoREL. 1,842,602

AUTOMATIC TELEPHONE SYSTEM Original Filed April 4, 1925 l'mrenur Fernand Eni-rural Patented Jan. 26, 1932 FERNAND GHOREL, F PARIS, FRANCE,

ASSIGNOR, BY MESNE ASSIGNMENTS, TO

ASSOCIATED ELECTRIC LABORATORIES, INC., 0F CHICAGO, ILLINOIS, A CORPORATIO OF DELAWARE AUTOMATIC TELEPHONE SYSTEM rg'inal application filed April 4, 1925, Serial No. 20,609, and in France May 15, 1924, Patent No. 1,670,303, dated May 22, 1928. Divided and this application led. December 19, 192?, Serial' No. 241,018.'

The present invention relates in general to automatic telephone systems but is concerned more particularly with such systems in which the toll or long distance connections are established automatically. One ot' the objects oi iny invention may be said to consist ot the production of new and improved toll repeater circuits whereby a subscriber can operate automatic switches in a distant exchange to extend a connection to a desired called line.

In such systems toll charges may be assessed against the calling subscriber by operating his message register a number of times to assess a line charge when the called party answers and thereafter reoperating the registen at stated intervals to assess an elapsed time charge proportional to the length of the conversation. Accordingly, a further object ot my invention lies in improved circuits for the control of the message register to assess toll charges.

rloll lines, to be eliiciently used,` must handle tratlic in both directions. Therefore each end ot the toll line must be equipped with incoming switches. In the usual practice, a selector is associated with the incoming rcpeater to handle incoming calls, in which case the number of selectors must correspond with the number of toll lines. A considerable saving in the number of selectors required can be eil'ccted by the use ot a line switch associated with the incoming repeater for the above purpose. This line switch may have access to a small number of incoming selectors or may have access to the regular local selectors. For such use a preselecting line switch is preferable. Accordingly, a further obj oct of -my invention may be said to consist ot' an improved preselecting rotary line switch adapted to work in connection with the repeater hereinbefore set forth, to complete incoming calls from a distant exchange.

Some of the above features ot this invention are claimed in the copending application Serial No. 20,609, filed April 4, 1925, of which the instant application is a division. Aecordingly, only such objects and features will be claimed in the instant case which are not protected in the parent application. These features may be found in circuits and operations of the repeater and associated line switch, and consist chiefly in novel provisions for reversing current over the calling subscriber-s line by means of a polarized relay connected in a simplex circuit to the toll line; in a preselecting line switch whose control circuit .is closed by a relay operated ov-er a simplex circuit; and in the operation of a two-stage relay controlling the line switch.

Other objects of this invention will be apparent from the detailed description s and claims which follow.

The accompanying drawing shows diagrammatically at R. a repeater, which can be used for incoming and outgoing calls, together with its arrangement for multiple metering the duration ot' a call; it also shows at C a preselecting secondary line switch. This switch comprises a group ci"` two relays 63 and 64, a rotary magnet 71, wipers 7 2-74, and bank contacts 75-77- The re-lay'Gll is provided with a locking device, which prevents all its contacts except the contactbS from operating. When the relay 63 is energized, the locking device ot the relay 611- is released thus enabling all the contacts of the relay 64 to operate.

At the incoming end the toll line represoi 1ted by the conductors 78 and 79 teril'linates in a repeater similar to the repeater R, and the description of its operation at the exchange where the line comes in is made with reference to the apparatus shown at R and C.

An outline will now be given of the operation of the system.

Vhen the calling subscribe-r has been connected to a repeater such as the repeater R, which serves a toll line, he takes into use an incoming selecting device at the distant exchange over a repeater, suoli R, and asceondary line switch such C. In response to the operation o't the callingsubscribers numbor dial, the repeater It. at the outgoing exchange transmits current impulses over both the line. leads in parallel. The repeater R at the incoming exchange transforms these impulses into other .impulses suitable for operating` the selecting' devices at the incoming exchange. Y

lVhen the wanted subscriber answers, the

`in this circuit.

current in the toll line is reversed and sets in operation the metering device. The operation of the calling subscribers meter is retarded sufficiently long to enable him to ascertain that he has obtained a connection with the wanted number. 1f the conversation exceeds a predetermined length of time, the calling subscribers meter is operated a second time, ,but a few ,seconds before this second operation is effected, they subscriber is warned by a special tone `put on his line.

lVhen the calling subscribers instrument has been `connectedoyer ya selector to the repeater R, Ythe relay 6 is energized in thecircuit: battery, upper winding` of the relay 6, fback contact 18,'banlr contact 2 of theselector, the `calling subscribers line and instrument (not shown), selector vbank contact 4, back Contact 19, lower' winding of relay 6 and ground. Upon energizing,the relay 6 closes .a circuit atthe impulse contact 21. The rela-y 7 isenergized in the circuit: ground, l.winding of vrelay 7, front contact 20, resistance 83 and battery; at the iront contact ot it puts ground on the ltest contact 3 of the selector bank, thus marking the line engaged and holding the selector in its operated position.

At -the `front contact 23, the relay 7 prepares the circuit of the relay 8, at the front contact of26, it prepares the circuit of the in- .fterrupter M1 over the electromaguet 17, and at'the front of 24 it closesthe circuit of relay `121andof the left hand :winding of relay 13. `Ast-he relay 13 is polarized, it is not operated Upon-energizing, the relay 12 at the bach contacts 39 and 41 disconnects the uepeating coil T from the secondary line switch, and atrthe'front contacts itconnects the coil'to the calling line. At the' contact the ground on the flead 60 in series Vwith the relay 14 and the right hand winding oi' the relay 13 is disconnected and is replaced bythe battery inseries with the resistance 22 and the contact 21.

This .battery being connected to the two conductors ofthe toll line, causes the ener-V gizationof a relay corresponding to the relaay 14at the repeater at the distant exchange over the following circuit: battery, resistance 22, front contact 21, front contact of 40, right ,hand winding of the relay 13, winding of the relay 14,.the two windings of the repeater T iin parallel, the two leads 78 and 79 ot' the toll 'li-ne, the two .windings of a repeater similar lto the repeater coil T atthe repeater iniithe 'incoming exchange such as R, the relay 14, the right hand winding of relay 13, theback contact of 40, back contact 49 and earth. Y y

At the repeater at the incoming exchange. the relay l14, on energizing,"vv closes the front contact of 44, thus establishing the circuit of relay 15, and at the front contact of 43 it prepares-a loop across the line of the secondary line switch C. The relay 15 is energized in the following circuit: ground, back contact of 24, winding of relay 15, front contact of 44resistance 83 and battery. At the front contact ot 45 relay 15 puts ground on the test Contact 3 in the selector bank over the back contacts 25 and 34, thus marking the line engaged at ,the selector in the incoming exchange; at the' contact 48 'it closes a circuit over one winding' of the relay 16; at contact .46 it prepares the circuit of the relay 8; andiinally, at contact 47 it completes the loop across the line otthe secondary line switch in series with the left hand winding of the relay 16. The directionot the current in the vrelay 16 is such that therelay does notopen ate its contacts. y

The secondary preselecting'line switclrC, located at theincoming exchange, the operationY of which will be 'hereafter eXplained,is always set on the line of an idle selector, and, upon the energize-tion of the relays '14 and 15. thecircuit ofthe relays 63 and 64 is closed over: battery, contact 70, windings of the relays 64 and 63, back contact of 66, llead 61, back contact of 41, front contactsof43 and'47, winding (left hand) of the relay16, back contact of 27, lead`62,r back contact ot'69 and ground'.

Upon energizing, the relay 63 operates a locking device,thus enablingfrelayr64 to actuate all its contacts; at kthe back contactof 65 it disconnects ground Atrein the circuit of the magnet 71, and at the front contact of 65 Iit establishes a locking circuit in series with the relay 64. The relay 64, on energizing, connects the line to the selecting device at 66 and 69, and opens the circuitofthe rotary magnet at 67.

Then the line is connected to the selecting device y(not shown), its calling relay is energized in series -with the line loop and closes the circuit of the releasing relay, which-puts ground on the test lead andtest contact 75. By means ot the wiper 7 2,`this lground is connected to the end 'of the winding of relay 6 4, andthe relay 63, being short circuited, releases, while the relay 64 remains energized. rllhe toll line has now been connected across the repeater R over the -selecting device in the incoming exchange. .At the outgoing exchange, the relay 14 of the repeater Vis also energized in the circuit above described. but this has no eff-ect because the circuit of relay 15 is open at the back contact of24. v i

Yv'hen the subscriberoperateshis number dial for the remaining igures ofthe wanted subscribers number, each interruption of the line by the number dial causes the relay 6 to open the contact 21 Vand at backcontact 20 it closes the circuit of relay 8. The latter,'on energizing, opens the circuit of the left hand winding of .the repeater 4T and' suppressestlie cli'ect ol the condenser' 8() on the relay 6 during the impulses.

The short circuiting otl the relay 7 having rendered it slow acting, it remains operated during the impulses and the relay 8, after having been energized, likewise does not release until atter the train ot impulses.

:it the incoming exchange, the relay 14 re leases each time its circuit is opened at the contact 2l of the relay 6 in the repeater at the outgoing exchange, and at its contact 43 it repeats those interruptions in the line ot the selecting device tor the purpose of positioning the Wipers of the latter onto the line ol the wanted subscriber. At the back contact olI 44. the circuit of the relay 8 is closed and the relay on energizing` prepares at the trout contact ot' 2T a new circuit tor the impulses, which does not pass over the Winding of the .relay 1b. rlhc short circuiting otl the relays la and 8 having rendered them slow acting, they remain intheir operated position during the train et impulses, and then the relay on releasing, connects the repeater' to the line ot the selectingl device and closes the loop over the Winding of the relay 16.

`When the Wanted subscriber responds to the call. the current is reversed in the line of the selecting device and hence in the left hand winding ot the relay 16, and this reversal en ergizes the relay 16. Thereupon the relay 16 opens the circuit ot' the relay 8 at contact 50; it short circuits the contact 43 ot the relay 14 at contact 51, and at the contact 49 it replaces the ground connection by the special battery B2 in series with the resistance 5i". The voltage ot this special battery B2 is greater than the central battery ot the exchange, hence the direction ot the current in the toll line ia reversed.

This battery reversal on the toll line causes the relay 13 to be energized at the repeater in the outgoing exchange. The relay '13, on energizing, at 42 closes the circuit of the relays 5 and 10. On energizing, the relay 5 reverses the battery on thc line ot' the calling subscriber. Thus supervision is obtained. The relay 10, on energizing, closes the circuit at tor maintaining its upper winding energized; at contact 34'it connects the test lead to the contacts ot' the metering relay 9; at contact 32 it prepares a locking circuit tor its lower winding; at 31 it opens the release circuit for the magnet 17; and at 35 it closes the circuitot this magnet over the interrupter lvll. which operates slowly.

lt will be assumed that the wanted subscriber belongs to an exchange for which a three minute conversation costs three times as much as a local call` In that case the bank contacts of the apparatus, which has contacts, are connected in multiple as shown in the ligure, and the interrupter M1 closes its contact every 7.2 seconds. As the meterii'ig relay 9 is connected to the fourth,

sixth and eighth bank contact, the lirst operation of the subscribers meter is delayed for about 20 seconds, thus giving the calling subscriber time to release the connection betere metering it for anv reason he finds he is not connected to the wanted party.

lWhen the Wiper 54 reaches the fourth bank contact, the relay 9 is energized in the following circuit: ground, Wiper 54, fourth bank contact, lead 58, back contact of 37, Winding ot the relay 9 and battery. On energizing, the relay 9 at its contact 3() replaces the ground on the test lead by the special battery B3, for operating the calling subscribers meter, and at contact 29 it closes the circuit for the lower Winding of the relay 10.

At the moment this latter circuit is Without etl'ect, as the relay 10 is energized by its upper winding. When the wiper 54 passes onto the fifth bank contact, the relay 9 releases, which causes the meter oit the calling subscriber to tall back likewise after having` registered one unit. At the sixth and eighth bank contacts the meter is again operated, so that when the Wiper 54 reaches the ninth bank contact, the calling subscribers meter will have registered three units.

By the action ot' the nlagnet 17, the Wiper continues its rotation and, on reaching its last bank contact, it closes the circuit ot' the relay 11 over: ground, Wiper 54. 25th bank contact, lead 5G, lower Winding of the relay 11 and battery.

On energizing, the relay 11 at its contact 38 puts a. tone on the calling subscribei"s line to notiity him that his meter is going to be again operated. i

It the calling subscriber replaces his ieceiver before the wiper 54 for the second time reaches the fourth bank contact, the line relay (i, in fallin g back, opens the circuit of the relay '7, which on releasing opens at 24 the circuits of the relays l0, 12 and 13, and at the back contact of 2? prepares the rele; sing circuit tor the magnet 17. The relay l0, on releasing, removes at 34 ground from the test lead, thereby releasing the selecting devices; at contact it opens the circuit ot the mag net 17 extending over the contact 26, and at contact 31 it closes the circuit for automatically operating the magnet 17.

It the Wiper 54 is out ot its normal position, the contact 5b is closed and the circuit ot the magnet 17 closed from battery, the Winding of the magnet 17, the contact 52, the Contact 53, the upper Winding of the relay l1, the back contacts of 31, 23, 20 and to ground. The magnet 17, operating intermittently, advances the Wiper 54 to its normal position, in which the contact 53 is opened and the Wiper comes to rest.

The relay 11 is energized in series with the magnet 17 and puts ground on the test lead ot the repeater over the contacts 36, 25 and 34, thus preventing the repeater being taken iiitouse before the wiper 54 reaches its normal position.

The relay 12, on releasing, connects the toll line tothe secondary line switch, and at contact it again puts ground on the lead 60 in series with the relay 14. At the incoming .exchange the rela 14 releases when the iela leases when the circuit of its lett hand winding is opened at 43, and when it has fallen back, ground is again put on the lead in series with the relay 14.

It the calling subscriber hangs up his receiver while metering is taking place, the release oi' the switches at the incoming exchange takes place in the inanner above described, but at the outgoing exchange relay 10 remains locked untilthe metering has been completed. Thereby its lower winding is connected to the tiit'tli and seventh banlr contacts over the front contact of 32, and from the fifth to the eighth contact the circuit of its lower winding is closed either at contact 29 or by the wiper 54.

When the calling subscriber has hung up his receiver the relays 5, 6, 7, 12, and 13 :t'all back as in the case described above, but the preceding selecting devices are not releaset, because ground or special battery B8 is connected to the test lead at the contacts 30 and 34. lvhcn the relay 7 falls back, the circuit or' the rotary magnet 17 is connected to the interrupter M2 at the back contact of 26. This interruptor operates quicker than the iiiterruptci M1. Accordingly, the magnet 17 operates at such rate that the wiper 54 moves too fast for the meter to operate when the wiper passes over the metering contacts. The circuit of the lower winding of relay 1() is opened when the ninth bank contact is reached, and upon falling back, the relay causes the wiper 54 to stop, as described in the preceding case, in its normal position.

It the calling subscriber shouldhang up his receiver before metering has commenced, the magnet 17, in ope ating automatically, returns the wiper 54 to its normal position, and the relay 11, on energizing in series withthe magnet, opens at 37 the circuit ol' the meter ing relay7 9 iii order to prevent itsoperation when the wiper 54 passes over the metering contacts. Y

The function of the secondary switch C is to connect the toll line, to which it belongs, with the line of an idle selecting device ,hence when the'line, on which the wipers 72, 73 and 74 are standing, is taken into use, ground is placed on the test lead and test contact, such as the contact 75, and the test wiper 72 connects .this ground tothe winding of the relay 64. On energizing, the relay 64 -only operates the contact 68'owing to theloclring 'device,vand the circuit of' the magnet 71'is closed as follows: earth, back contact of 65,

back Contact or' 67, front contact ot 68, winding of the kmagnet 71 `and battery. The magnet 71, on energizing, opens at the circuit .63 is not energized because it is short circuited by ground on the test wiper; hence the relay cannot `be energizedk unless the wipers are standing on an idle line.

It the wipers are standing on an idle Aline f when the switch is taken into use by a :toll

line, the 'relays 63 and 64 are energized in series by the loop over thetwo leads of the line Gland 62, and in that case the relay 64, being unlocked by the relay 63, operates all its contacts,'and the switch operates iii the manner already described.

What is claimed is:

1. In an automatic telephone system, a toll line terminating in a repeater, a calling line,

ineans'for connecting said calling line Vwith said repeater, means in said repeater operable from said calling line to extend a connection over said toll line to a called line in a distant exchange, a polarized relay in said repeater,

a circuit for said relay including the two sides of said toll line in parallel, means operable by the response of the called party to reverse the 'current flow in saidA circuit, said polarized relay responding to said reversed current, and means controlled by said polarized relay for reversing the current flow in said callingline.

2. In an automatic telephone system, a toll line terminating in a repeater, a calling line, means for connectingsaid calling line with said repeater, means in said repeater operable from said calling line to extend a coniiec tion over said toll line to a called line in a'distant exchange, a. polarized relay in saidrepeater, a circuit for said relay including the two sides of said toll line in parallel, 'means operable by the response of the called party to apply booster battery to said circuit in the opposite direction to reverse the current flow therein` said polarized relayresponding l to said reversed current, and means controlled by said polarized relay for reversing the current `flow in said calling'line.

[n a telephone system, a calling `line,`a called line, a repeater, means in said repeater for extending a connection from said .calling line to saidv called line, a polarized relay in said' repeater, a circuit for said relay extending over an intermediate section of said connection and including two Vtalking conducall) tors oi' said section in parallel, means operable upon the response of the called party for reversing the current liow in said circuit to operate said relay, and means controlled by said relay for reversing the current flow 1n said calling line.

4. ln a telephone system, calling and called lines, switching means for extending a connection from a calling to a called line, a relay in said switching means, a circuit ior said relay extending over an intermediate section ot said connection and incliilding two conductors thereof in parallel, means operable upon the response of the called party 'for reversing the current flow in said circuit to operate said relay, a nd means controlled by said relay for reversing the current flow over said calling line.

5. In a telephone system, calling and called lines, switching means including a polarized relay for extending` a connection trom a calling to a called line, a circuit for said relay extending over an intermediate section of said connection and including` two conductors thereof in parallel, means operable upon the response of the called line for reversing the current flow in said intermediate section to operate said relay, and means controlled by said relay Jfor reversing the current flow in said calling line.

(l. ln a telephone system, calling and called lines, a two conductor trunk line, switching means including,` a polarized relay for extending, a connection from a calling` line to a called line over said trunk line, a circuit for said relay including 'the conductors of said trunk line in parallel, means operable upon the response of the called line for reversing the current flow in said trunk line to operate said relay, and means controlled by said relay Jfor reversing the current flow in said calling line.

7. ln an automatic telephone system, a toll line terminating in a repeater, a line switch associated with said repeater, said line switch being` arranged so that it is always in engagement with an idle trunk, a loop circuit for said line switch, means in said repeater operable over the two sides of said toll line in parallel for closing said loop, and means in said line switch operable in response to the closure of said loop to seize said idle trunk.

8. In a telephone system, a two-way trunk line havingl each end thereof terminating in a repeater and a non-numerical trunk hunting switch, respectively, at each of two exchanges, means at each end of the trunk for seizing` it to extend a connection from a station in one exchange to a station in the other exchange, and means operated over the two conductors of the trunk in parallel to cause the trunk hunting switch thereat to automatically extend the connection to a numerical switch.

9. ln a telephone system, a two-way trunk line havingeach end thereof terminating in a repeater and a non-numerical trunk hunt- FERNAND GOHOREL.

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