BE352429A - - Google Patents

Description

       

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   TELEPHONE SYSTEM.



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The present invention relates to telephone systems in general but more particularly relates to advanced branch office equipment in a telephone system employing both main offices and branch offices, although several of the features of the invention are not especially limited to this equipment. The general object of the invention is to provide improved circuit arrangements for systems of this kind so that the equipment can be reduced and the

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 operation be made safer while at the same time all the facilities usually provided are available.



   A characteristic of the invention is the application of the so-called diversion method of operation to branch office switching devices, so that a single digital switch is sufficient, this switch being used only to operate the switch. line switch on the called line to force it to seize the same trunk line that was previously taken in service by the line switch of the calling line.



   Another characteristic of the invention resides in the arrangement according to which each of the ten trunk lines controlled by a main switch is normally connected to the common connector switch, but is disconnected from it and instead connected to an individual supply relay. battery and restraint as soon as a connection has been established by means of the trunk line.



   According to another characteristic of the invention, the main switch is arranged so as not to operate to choose a new trunk line as soon as a call is finished, but to wait until the common connector has been activated through the trunk line taken in service to send the signal to the called subscriber and to operate the line switch of the called line to establish a connection to the calling line through the intermediary trunk line in use, after which the main switch operates in the usual way to choose another free trunk line.



   Another feature of the invention consists in providing a device in time, specific to the individual motor, to release the connector automatically in the event that the subscriber has not dialed the full number and has thus obliged the connector to be released when it is disconnected from the junction line where it has been mounted higher. Do more, the

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 The device in time is released and restarted after the full number has been formed on the dial to control the application of the ringing current and the regular release of the connector.



   Another characteristic of the arrangement is that the ringing current is transmitted as soon as the call has been broken down, a short preliminary ringing being given only at this time. A moment later, the timing device causes a long ring to be transmitted to the called line. This long ring is useful in a private automatic office in order to locate the station which receives the signal when several stations are located one after the other, for example on pupi
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 very adjacent to an office.



   Another feature of the invention is to provide provisions in the connector to prevent the connection of a battery with a trunk line when a communication is being established by means of oella-oi.
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 to the main office or V81.'êJ a ctirl, nln 6qulIHltnQnh looril (a code call machine for example) while allowing a battery supply connection to be established in the event that the call is a call regular local. This allows the subscribers to the branch office to dial the numbers of the main office and special looaux numbers. In addition, the local supply of battery is also prevented in the event that a call arrives from the main office.



   Another feature of the invention consists in providing suitable arrangements to allow an attendant, in an attendant booth associated with the junction lines between offices, to answer and extend incoming calls from the main office to answer calls. arriving at his booth coming from the branch office and establishing dialect communications between subscribers of the main office and the branch office.



   According to another characteristic of 1) invention) a dis-

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 improved position is provided whereby the busy sound current and the dial control sound current are transmitted to the connector from the sound equipment by means of the same inverter, arrangements being made to ensure that the sound current flow is distinctly different at one time from the sound current flow at another time, so as to differentiate between the dial operating sound and the busy sound.



   These characteristics of the invention will be more clearly understood (1-after the description given below of an embodiment, this description to be taken in conjunction with the accompanying drawings, It is however obvious that the arrangement described is given by way of example only and that various modifications could be made thereto by those skilled in the art without departing from the scope of the invention.



   With regard to the drawings comprising FIGS. 1 to 5, the latter show, by means of the usual diagrams of oircuit, what is required of the equipment of a telephone system comprising the characteristics of the invention so that this last can be understood. These drawings show more particularly the equipment located in a main office indicated to the left of figure 1, and the essential equipment of a branohemont office connected to the main office by means of the junction line TL, figurel, and others.

   The branch office can be considered to belong to the type ordinarily called a private branch office, with an attendant placed at the branch office to complete incoming calls, verifying the desired number and controlling the operation of the automatic switching equipment. , the outgoing calls being completed under the effect of the dial operation on the part of the calling subscriber, without the assistance of the agent of the switching office.



   The equipment shown in Figure 1 comprises the part of the main office equipment left-handed / and right-black

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 fired from junction line To at the inlet end of the junction line TL. At the lower part of the figure, we have indicated certain keys and lampas located in the pre-school board and specific to the TC connection circuit. The remaining part of the attendant's equipment is shown in Figure 4 which should be placed under Figure 1 with the connecting lines extending from each other. The keys and the other devices in figure 4 are common to the different junction circuits oo ... me the TC junction circuit, figure 1.

   FIG. 4 also shows two so-called intelligence junction lines extending towards the attendant's table coming from the local switching equipment) for a purpose which will be explained below.



   Figure 2 shows line switches LS1 and LS2 having common access to the trunk line comprising conductors 226-229 and to other trunk lines controlled by the associated main switch MS. The main switch is arranged in a known manner to associate all free line switches with a trunk line which is free. the line switch LS1 is specific to the line of the local set A while the line switch LS2 is specific to the trunk line TL to which it is associated via the trunk circuit TC, figure 1 , since it is connected to this jonotion circuit by means of conductors 125-129.



   Figure 3 shows the single connector of the branch office, with wipers 322-325. Via the common conductors 219-221, this connector is normally connected to each of the junction lines accessible to the line switches, one of these junction lines being that comprising the conductors 226-229, figure 2. This connector has access to each of the lines and to each of the branch office line switches. FIG. 3 also shows the control equipment and the auxiliary equipment comprising the twelve-position rotary switch and its associated relays and the bell switch BI.

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   Figure 5 shows the call to oode device, containing the line switches LS3 and LS4 associated with the string answer and string call number, respectively, and the CS code selector comprising the slider 507. This device is accessible. to the connector shown in Figure 3 through the fixed contact shown to the left of Figure 5 and is designed in a manner which will be explained below. Line switches LS3 and LS4 are under the control of the main switch shown in Figure 2.



   From a mechanical point of view, the main switch shown in figure 2 as well as the line switches LS1 and LS2 of the same figure and the line switches LS3 and LS4 in figure 5 are of the usual type, the plungers of the switches line being preferably of the self-return type) by this is meant a plunger which, when released, immediately returns under the control of the main switch without waiting for the main switch to return to the position of. where the line switch was actuated. The connector shown in Figure 3 is, from a mechanical point of view, of the well-known vertical / rotary type having its fixed contacts arranged in horizontal rows or stages.



   The apparatus having been deorit in general, we can move on to the detailed description of its operation. To have effect we will suppose. that the subscriber of posta A dôsire oonvorsor with another local subscriber.



   When the receiver is removed at station A, the line relay 203 of the line switch LS1 energizes by means of the two conductors of the calling line and of the circuit of the station in series, and closes a circuit passing through the attraction winding. of the line switch by means of the conductor 202, at the same time deactivating the operating conductor of the following line switches. The earth on the conductor 202 is obtained by means of the upper oontaots of the relays 307 and, 304 of the connector figure 3, and by the intermediary of the lower winding of

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 .High resistance of the 20I delay relay. As long as the high resistance lower winding of this relay is not bypassed, the line switch is prevented from operating.

   The delay relay is slow to function owing to the high impedanoe of its lower winding which prevents the rapid formation of current and as a result of the upper oourt-ouit winding of the relay, which winding is on the side of the armature of the relay and therefore prevents magnetic flux from reaching the armature soon after it has been established.



  The delay relay is intended primarily to take account of the situation which could arise in the event that a line switch tries to re-energize immediately after being released, in which case it could dive to a trunk line other than the one. chosen by the main switch if it was allowed to operate before being returned to the main switch position.

   When the relay 201 is operating, it places the low resistance upper winding in parallel with the lower winding, whereupon the attraction winding 205 is magnetized enough to operate the armatures 206 and 207. causes the line switch to dip and close the line switch oonneotion to the trunk line comprising conductors 226-229, and also disconnects line relay 203 and ground of the calling line conductors.



   The line relay 305 of the connector then operates through the calling line through the conductors 226 and 229 of the connection line taken in service and the conductors 219 and 221 of the motor. In operation, line relay 305 forms a circuit for relay 306, after which relay 306 operates and closes a loop for relay 307 which, at its bottom armature, connects earth to the release junction conductor 223, , which closes a restraint by
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 the test wiper of the main switch and by the junction motor 227 and the contacts of the line switch LS1.,

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 for the bridge interruption winding. 204 of the line switch.

   This circuit is established before the slow wave relay 203 has had time to drop out and it is used to keep the armatures 206 and 207 of the line relay activated,
Another result of the operation of relays 306 and 307, Figure 3, is that the switch is prepared for operation.
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 ment by the infériquro reinforcement of the z06 ralaie nt that the tqrr'9 have removed, at the location of the upper reinforcement of 307, from the delay relay, 201 relay which drops back in preparation for the next call. It can be seen from the above that no other line switch can be operated from calling lines at the moment, because the earth is removed from the contact chain of the line relays.
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  The ringing of the relay 30 '/ also initiates the operation of the bell switch RI by connecting the earth to the conductor 370, and by connecting the earth to the conductor 361 it also activates the sound generator 368. When the left winding of the operating magnet is energized via the associated resistor, the lamella is attracted to the left, after which the right differential winding is energized in the opposite direction, which forces the magnet to release the slat which swings to the right. The right winding is de-energized and the lamella is attracted again.

   The intermittent flow of current through the lower cortacts of the lamella as the continuous vibration travels into the primary winding of the associated transformer and induces an alternating ringing current in the secondary winding. Connecting the earth to conductor 361 energizes relay 368 through its lower winding, after which it shorts itself and releases itself, producing a sound which is sent to the calling subscriber. by the conductor 362 and serves as an indication of maneuvering of the cadan.

   The earth provided by the relay 307 is also extended by the conductor 360 and the contacts 355 of the rotary switch in its first position to energize the start relay 367

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 The latter this vorroulllo then. himself ind6ponclwatriont doo oon- taots 355, opens the switch recall button) prepares a circuit to operate the bell trip relay 309 and initiates the operation of switch relays 365, and 366. Relay 365 accordingly operates intermittently and prepares a sound to interrupt the sound to give a busy signal and also sends pulses to the magnet 350 of the rotary switch.



   On hearing the dial-up signal, the calling subscriber forms the first digit of the desired number on the dial, number 5 for example, after which line relay 305 momentarily attracts its armature five times. Each time it does so, a circuit is closed by the lower armature of the release relay 306 'for the vertical magnet 317, this circuit containing, at the time of its first closing, the lower spring out of normal. Assooié, the upper spring 315 and the lower oontaots of the relay 303. By the function of the vertical magnet, the wipers 322-325 are gradually raised until they are in front of the fifth stage of fixed contacts.

   The re-
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 left 300 out aoiionn6 multiple end avoo the magnet vorl! ual 15I? after the first current pulse and since it is slow-acting, it remains energized throughout the pulse train, which keeps its own circuit and that of the vertical magnet intact after the contacts out of range. normal have moved as they do during the first vertical advance. At the end of the vertical movement, relay 308 drops off and transfers the operating lead from vertical magnet 317 to rotating magnet 319.



   When the next digit is formed on the dial, digit 6 for example, line relay 305 is de-energized six times momentarily and transmits a pulse to rotating magnet 319 each time it de-energizes. These pulses are transmitted through the lower armature of relay 306, the two lower out-of-normal contacts associated with spring 315,

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 the lower armature of the rail 308, the normally closed oontaots controlled by the lower armature of the relay 310 and the contacts of the relay 312. The magnet 319 operates under the effect of these pulses and causes the joggers 322-325 to turn by jerk - until they engage with the sixth series of fixed contacts (not shown) at the fifth floor.

   The relay 317 is energized in multiple with the magnet 319 during the rotary movement and at its internal upper armature it deoons the test wiper 323 from the test winding of the switching relay 312 and connects it to the places, by means of switch contacts 321, the combined advance and output relay 310, and in its lower armature it places a bypass around the associated oontaots of relay 310 so as to prevent interruption of the circuit of actuation of the rotating magnet during the rotational movement in the event that the relay 310 operates by causing this movement due to the presence of an earth on a test contact encountered by the test wiper 323 during the rotary movement.



   Assuming first that the line of the desired subscriber is busy when called, relay 310 is energized by means of test wiper 323 by the earth encountered by that wiper when the wipers of the connector come to rest on the fixed contacts of the called line, and when the relay 31I drops out, the circuit of the rotating magnet 319 and its own circuit are opened at the lower contacts of the relay, which prevents the continuation of the rotational movement of the selector in the event of a new operation of the calling device at the calling station. Note that relay 310 is presently locked in the energized state by conductor 370 by means of its own internal upper armature and switch contacts 321 of the rotating magnet.

   It should be further noted that there is no need for the latching circuit of relay 310 to be controlled by relay 311 to prevent relay 310 from latching.
1st during the rotary motion, as is / is usually done

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 because in the present case, the rotating magnet 319 opens the baked oir of relay 310 each time the wipers advance, With the occupancy relay 310 energized, the earth is extended from the motor 370 by means of the upper contacts of the relays 3II, 310 and 308 until the junction of the winding of the relay 368 and the associated resistance) by means of the upper oontaots of the switch relay 365.

   As a result, relay 368 is intermittently shorted when relay 365 pulls in and drops out causing it to emit an intermittent buzz instead of the continuous buzz emitted previously.



  This intermittent buzzing is recognized by the calling subscriber as the busy signal. While waiting for this signal, the calling subscriber hangs up his receiver, which allows relays 305, 306, 307 and 310 to drop out and results in the release of the connector and the calling line switch LSI.



  In this case, the main switch did not advance and on the next call it takes the same trunk line.



   If we now assume that the desired line is free when called, the occupancy relay 310 is not energized at the end of the rotary movement and the relay 312 is actuated in its place) the relay 3II then drops and connecting the upper coil of relay 312 to the wiper 323. The circuit of the relay 312 extends from the conductor 370 through the contacts of the relay 310 to the upper coil of the relay 312 and from there through the contacts of the relays 3II and 312 to the wiper test 323 and is supplemented to the battery by the interrupt winding of the called line switch, which winding is similar to the winding 204 of the line switch LS1.

   The energization of this winding results in the operation of the interrupting armature corresponding to armature 206, which frees the called line from its normal battery and earth connections.



  Relay 312 operates through this circuit and at its internal lower armature it locks itself to conductor 370, at the same time removing the operating potential of the relay from its 368, after which the relay buzz operation.

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 368 ceases and the application of the buzzing sound to the lower conversation conductor is no longer made.

   Another result of the operation of relay 312 is that it disconnects the rotating magnet.
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 tif 319) to oon l..lr !! l <.lLuro aupurluuro l11LrH'110 il dooounaoLa 10 test frother 323 of its own upper winding and connected it directly to earth so as to keep the winding energized interrupting the line switch called :, and at its upper and lower oon tacts it connects the wipers 322 and 325 to the ringing circuit. The lower slider is connected to the bell conductor 363 and the upper slider is connected to the upper winding of the bell interrupt relay 309.



  The application of ringing current to the called line is done in a manner which will now be explained.



   It was previously mentioned that the time apparatus, including the twelve-position rotary switch, is turned on when the start relay 367 operates from conductor 370 by means of the contacts of relay 311 and switches 355 when the switch is taken in service. When operated, relay 367 locks itself to conductor 360 at its inner bottom frame, and at its top frame it initiates operation of switch relays 366 and 365. Relay 366 closes a circuit for the switch. relay 365.



  Relay 365 operates and short-circuits relay 366 which then drops out by switching off and on-open relay 365. Relay 365 drops out and clears the short-circuited relay 366, which allows relay 366 to refonotate.



  This operation continues as long as relay 367 is actuated. This operation is slowed down and made uniform by the copper collars on the ends, located on the side of the armatures, of the relay cores, which are thus made slow to operate and slow to unhook. Each time the relay 365 operates, it closes a circuit from the grounded conductor 360 to the magnet 350. Each time the magnet 350 falls back, after having produced its attraction by this circuit, it does.

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 advance the ratchet device one notch, each notch representing a separate position among the twelve positions. The pulses are launched at a rate of about two per second.



   The device is turned on when the connector is taken in service, so that the connector can be returned to common use at the expiration of about four and a half seconds in the event that the formation of the second digit at the dial n has not started in the meantime. This action results from the operation of the interrupt relay 309 by means of the contacts 354 in position 9 of the device and in a manner which will be explained.
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 anno la su, tr, Lorriqtio 10 "t '() lda: 3IJ:

   atxanno no-in 7.r, cFnt da the second and last series of pulses of the number, it removes the earth. to its upper armature, of the switch starter conductor 360, following raxxxxx whereby the starter relay 367 drops out and closes a circuit, return for the switch in time, closing a circuit for the relay feed 364 through contacts 352 (closed in positions 2 to 12) and switch contacts 351 of magnet 350. Relay 364 operates and at its lower armature closes a circuit for 1 {magnet 350 , after which this magnet operates and opens the oirouit of the progress relay. The advancement relay drops out and allows the magnet to de-energize, resulting in the switch advancing one notch in time.

   When the magnet disengages, the circuit of relay 364 is reestablished, The relay and
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 the magnet operating altormativomont in this manner until 00 until the reset button is open when the switch goes beyond position 12 and reaches position 1. Note that the starter relay 367 cannot aps refono- Operate to open the reset circuit until the switch has reached position 1 due to the start relay 367 opening by releasing its latch circuit.

   When the start relay 367 operates again due to the fact that the time switch arrives in its position 1 or due to the fall of the relay 311 at the end of the second digit

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 fre, whichever of these eventualities comes last, the. switch relays 365 and 366 start again to operate the magnet in time 350.

   While the time switch is still in the I position, the ringing current from the secondary winding of the ringing switch is initiated into the ringing conductor, which sends the ringing current into the calling line through them. lower contacts of relays 309 and 312, this ringing current returning through the upper line conductor, the wiper 322 and the upper contacts of relays 312 and 309 to the battery by means of 1 upper winding of relay 309.

   The slow acting bell interrupt relay 309 is then actuated by this bell current as no continuous current flow occurs as a result of the intercalation of the usual capacitor in the bell circuit at the station. bell ring is open at contacts 356 and conductor 336 is directly earthed while the time switch is in position 2, but in positions 3 to 6 the bell circuit is closed again and a new, longer application of the ringing current takes place. Ringing current is applied in this manner so that the particular telephone which is ringing can be readily recognized when several telephones are mounted close together.

   The preliminary short ring draws attention to the call, and the long ringing signal shortly afterwards recognizes the correct telephone. Part of the ringing current returns to the calling line through the small capacitor 385 i, which informs the calling subscriber of the ringing operation by means of the usual ringing back sound.



   The ringing interrupt relay can be actuated by means of the called line in the event that the called subscriber answers after the communication has been completed by the switching relay 312. The relay 309 is actuated in this way by its upper winding by means of the called line and

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 it locks itself to the conductor 370 to its internal lower frame. If the relay 309 is not activated in this way, it is activated automatically by the device at time when it arrives in position 5. The circuit passes at this moment from the earth through the conductor 370, the lower internal armature of the device. relay 312. the contacts 353 of the timing device, the conductor 359 and the lower winding of the relay 309 to the battery.

   When operating, relay 309 locks itself to conductor 370 at the location of its inner bottom frame} it opens a point of the main switch starting circuit at the location of its third frame from the bottom, it disconnects the upper and lower wipers, its upper and lower reinforcements, which stops the passage of the ringing current towards the called line, and with one of its lower reinforcements it connects the earth to the conductor 224 which makes Function relay 304 to open a new point in the earth supply connection to relay 301 (figure 2), and connect the earth to attraction contactor 324.

   by closing a circuit through the fixed contact on which the wiper 324 is located for the attracting winding of the called line switch, similar to the winding 205 of the line switch LS1. When oeoi occurs, the line switch of the called line operates and connects the called line to the trunk line to which the calling line is connected, because the main switch is still in the same position. As soon as the line switch of the called line operates its upper coil is energized in parallel with the winding 2'04 of the line switch LS1 from the conductor 227 of the connection line, which winding is used to maintain the line switch actuated after the flow of current through the attraction winding has ceased.



   Another result of the operation of relay 309 is
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 that it l '/ jl'JI1f3 to its 1: 1l'! 1l /: l.Ltu: 's tJu, lJúl'leUi's internal a circuit going from earth through the upper armature of relay 306, through the ar -

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 rolais 301, the cam springs "30" and "00" and by the interrupt conductor 222 and the wiper 232 of the main switch to operate the interrupt and battery supply relays 2I8 and 217 of the line junction by which the communication was completed.

   Relay 318 operates when this circuit is closed and locks itself, at the location of its internal upper armature, to the earthed conductor 227, at the same time opening its initial circuit, it disconnects the conductors 226,228 and 229 from the junction line of the corre- sponding conductors 219, 220 and 221 of the connector to its upper armature and its soft lower armatures, and at its upper middle armature it extends the earth potential up to the in upper bearing of the battery supply relay 217.



  This relay is marginally adjusted and does not work if resistor 320 (figure 3) is included in its circuit. However, resistor 320 is shorted at this time at the associated contacts, resulting in relay 217 operating and locking itself at junction conductors 226 and 229 to l. place of its lower and upper reinforcements, at the same time opening its initial circuit. Relay 217 then remains energized by the calling and called multiple lines and supplies the conversion current to the transmitters through its upper and lower windings.

   In its internal upper armature, the relay 217 places a multiple earth on the restraining conductor 227 so as to keep the two line switches activated and to maintain a test potential nnr In corresponding contact in the ( the fixed contact of the main switch test wiper The two subscribers can then converse with each other by their respective lines and by the conductors 226 and 229 of the trunk line.



   In the connector, the line relay 305 drops out when the trunk line is disconnected from the connector by the

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 -relay 218, and relay 306 drops a little later, by opening the ouit of relay 307, after which relay 307 drops out.

   Releasing relay 306 removes earth, at its upper armature, from interrupt conductor 222, and falling relay 307 removes earth at one point, from releasing junction conductor 223, leaving the line switches maintained only by means of the earth potential supplied to conductor 227 of the connecting line at the location of the internal upper armature of relay 217. At its upper armature, relay 307 prepares to replace earth on the earth supply conductor 202 (figure 2), removing at the same time the earth of the interlock and starting conductor 370, stopping the operation of the bell switch and the relays associated with the time switch,

   and causing the relays 309 and 312 to de-operate. The start relay 367 of the time switch then drops out and causes that switch to return to the normal position as indicated above.



   With relays 307 and 309 de-energized, the release junction conductor 223 is connected through the contacts of these relays to the starter conductor 225 of the main switch, resulting in the earth encountered by the escrow contactor. sai from the main switch, on the test contact associated with conductor 227 of the trunk line, energizes the start relay of the main switch to force the main switch to choose another trunk line, as will be explained in the following.



   Under the effect of the de-operation of the oonotor relay 306, the release magnet 318 operates via the associated contacts outside normal 316 and the contacts of the relays 305 and 306 and returns the connector to its normal position. male in the usual way. The release magnet circuit is open to out-of-normal contacts 316 when the normal switch position is reached.



   When the conversation is over, both subscribers

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 replace their reducers, after which the battery supply relay 317 drops out and disconnects itself from the trunk line at the same time removing the earth of the conductor 227, after which the relay 218 drops out. The bridge interrupt windings belonging to line switch 1LS1 and called line switch then both de-energize, after which the line switches are returned to normal and due to their self-aligning plungers, 1 they come immediately under the command of the main switch in front of the junction line chosen at this time.

   The communication is then disconnected and the apparatus is ready to be used to complete subsequent communications.



   The main switch MS is of the usual mechanical type and advances to choose junction lines under the effect of the energy supplied by the U-shaped spring designated by 237 and shown just below the solenoid 236 of the main switch. This main switch is shown in the occupied position just after the solenoid has operated to align the plungers opposite the tenth trunk line, which is the trunk line shown in the drawings.

   When the start relay 233 is actuated by means of the test wiper and leads 223 and 225, the ground control conductor 224 is then grounded to the upper armature of the start relay. rage so as to keep the connector relay 304 actuated during main switch operation and at the lower armature of the start relay a circuit is closed for the latch relay 234, after which the relay 234 operates and establishes a new connection to ground for the conductor 224 and unlocks the associated segment, which allows the U-spring to advance the main switch to the next trunk line.

   If the next junction line is free the starter relay 233 drops out immediately, followed by the locking relay 234 which stops the main switch on the junction line, If the control line is

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 'junction is occupied instead of free rub it with 8': [. d.



  231 of the main switch encounters an earth potential
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 uur the ouLuut oufjnl do la l.lyo do jouoLion where the start-up is kept pressed, and the advancement of the main switch continues.



   When a free trunk line is found, the start and lockout relays drop out, which turns off the main switch on that line. With the start relay and the locking relay both de-energized, and with the bell interrupt relay 309 of the connector de-sexed under the effect of the previous release of the connector ,. the circuit of relay 304 is open and this relay drops out, which reconnects the earth to the earth supply conductor 202 (figure 2), through the delay relay 201. The switchgear remains in this position. position until another call is made.



   Assuming now that the main switch has stepped forward until it is now on the first trunk line, and a communication including this trunk line is established, the start relay operates as described above during the release
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 tion of the connnotor FlprCJf3 7uc la oOIrJ.I11 \ 1n: Î.oRt'ion a 6t4 M.nh1în.



  At this time, the trip relay 235 energizes in multiple with the latch relay by means of the associated finger-operated contacts, held in engagement by the upper finger of the main switch. On energizing, the deolanohment relay locks the locking magnet to earth at the location of its right-hand contacts, and at its internal contacts it closes an oirouit for the adenoid 236 of the main switch which forces the switch. main to operate in a clockwise direction.

   The disconnection relay circuit is open as soon as the main switch begins to move, but the springs remain mechanically immobilized in the actuated position, by the locking spring.

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 ge controlled by the lower finger of the main switch,.: which is held out of engagement with this locking spring.



   When the main switch reaches the position shown in the drawings, the lower finger of the main switch unlocks the mechanically locked springs of the trip relay, allowing them to open the operating circuit of the lock relay and the main switch. . If this junction line is free at this time, the start relay is not actuated and the locking magnet drops out.



   It will now be assumed that the subscriber of set A wishes to converse with a subscriber whose line ends in the main office.
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 oipal. The prooud & r ooni on for the calling subscriber to remove his receiver and dial the number of the desired line of the main office preceded by the number 0 which is necessary to extend his line to a successful junction line. - health at the main office.



   When the receiver is removed, the line switch LS1 operates in the manner previously described and takes possession of a connection line, for example that shown in the drawing, comprising the conductors 226-229. When this occurs, the connector and other apparatus shown in Figure 3 operate in the manner previously described.



   When the calling subscriber forms the preliminary digit 0 on the dial, ten current pulses are sent into the vertical magnet 317 ,, so that the rubbers 322-325 are jerked up until they come to the end. tenth floor faoe rest of fixed oontaots.

   When the switch shaft brings the wipers up to the tenth stage (the "o" stage), the shaft springs 3I3 of the "0" stage are closed, causing the relay to operate. 303 from grounded conductor 228, through contacts of relay 218, conductor 220, switches of relays 303 and 301, and contacts 313 of the "O" stage.

   the conductor 228 being earthed through the corresponding contacts of the line switch LS1. The relay 203

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 operates and at its upper armature it removes the short-circuited from the winding of the relay 301 and extends the earthed conductor 220, by means of the spring 314 of the eleventh rotary advancement and its right contact, of the internal upper armature of relay 308 and switch contacts 321 to advance relay 310.

   This circuit is completed just at the end of the last vertical feed and while the slow acting relay 308 is still multiple energized with the vertical magnet 317. The feed relay 310 operates by means of this circuit and locks itself on. even to the conductor 370 to its internal upper frame, at the same time preparing a hole for the rotary magnet 319 to its lower frame. Relay 301 trips in series with relay 303 under the effect of the short-circuit of relay 301 being removed by relay 303 and removes the bypass around resistor 320 in conductor d. 'interruption.

   Incidentally, the relas 301 locks itself, at the location of its internal upper armature, to the battery via the internal upper contacts of the relay 306 and the associated resistor, which sets this resistor in bypass. around relay 303, but this operation has no particular effect at this time.



   When the slow-acting relay 308 drops, it opens the initial circuit of relay 310 to its internal upper armature and completes the circuit of the rotating magnet by means of the lower armatures of relays 310 and 312. Relay 310 remains latched, at the end of the circuit. 'place of its upper internal armature, to the conductor 370 so as to keep the circuit of the rotating magnet closed. Under the effect of the excitation of the rotating magnet 319, the wipers 322-325 are rotated until they are engaged with the first set of fixed contacts of the tenth stage. Relay 311 is energized in parallel with the rotating magnet and transfers test wiper 323 to the feed relay circuit 310, at its internal top armature.

   Towards the end of its stroke, the rotating magnet 319 opens, at contacts 321, the cirouit of relay 310,

 <Desc / Clms Page number 22>

 so that the relay 310 drops out and opens the cirbuit of the rotating magnet, which forces the rotating magnet to drop out and closes the oontaots 321 again.



   If the connection line ending in the first set of contacts of the tenth stage is occupied, the potential of
 EMI22.1
 orra net encountered on the contact of nrrni de ootte line do jono tion by the wiper 323, which again operates the advance relay 310. The relay 310 actuates the magnet 319 again, which causes to the rubbers a new advancement.



  This alternating operation is repeated as long as the scrubber 323 encounters cocuped contacts, and if all the junction lines are occupied, this operation continues until the wipers have advanced to the eleventh advancement position. rotating, which actuates the spring 314 which opens a pdnt in the hole of the rotating magnet and connects the grounded spring to the circuit of the relay 310 by the contacts 321, which keeps the relay 310 actuated so as to throw back the busy signal interrupted, from the sound relay 368 after the relay 311 drops off as previously described.



  The contacts above and slightly to the left of relay 301, which are also actuated in the "30" and "oo" positions now operate to bypass resistor 320 so that the trunk line battery supply relay can operate by means of conductor 222 in the event that the calling subscriber does not hang up but waits until after the call establishment operation occurs under
 EMI22.2
 the effect of the function, deorit above, of the bell interrupt relay 309, in position 5 of the time switch.



   If it is now assumed that the junction line extending from the fixed contacts of the "0" stage shown in the drawings and passing through terminals 256-257 to the line switch LS2, is found free, the wiper 323 does not meet the earth potential on the corresponding contact and / / the rail 310 does not energize after the wipers have come to rest on

 <Desc / Clms Page number 23>

 the series of contacts. In this case, the de-energization of the slow-acting multiple relay 3II is followed by the operation of the relay 312 by means of its upper coil, through the conductor extending through terminal 256 and the corresponding number terminal. of FIG. 2, from the conductor 127 and from the occupant lamp 153 shown in FIG. I, towards the battery.



  The oupation lamp comes on and the relay 312 operates by performing the functions described above. With relay 303 energized, closing the locking button for the lower coil of relay 312 closes a multiple button for the lower coil of relay 309 by the upper contacts of relay 303. Relay 309 then operates. and performs the functions described above, including grounding the pull slider 324 to cause the line switch to operate on the called trunk line, and ground the interrupt conductor 222 to its armature upper internal.



   When the slider 324 is grounded, a circuit is closed through terminal 257 for the attraction winding 2II of the line switch LS2, which operates the line switch to disconnect the line relay 209 and to set up. the connection with the junction line comprising the conductors 227-229.



  The springs of the plunger arms 212 connect the bridge interrupt conductor, grounded, 126 to the spleen coil - bare 210 so as to keep the line switch actuated.



  When earth is placed on conductor 222, it is obtained through resistor 320 due to the fact that relay 301 is now energized, and although the relay 218 of the junction line is capable of s 'to operate and lock itself to conductor 227, the marginal setting line relay 217 does not energize when the operating conductor is extended up to it, due to the presence of resistor 320 in series with the inverter. In! result);

   battery power is not turned on. 'local connection-

 <Desc / Clms Page number 24>

 .ment and the calling subscriber is thus enabled to operate the switches in the main office directly by means of his calling device as will be indicated later.



   With the line switches LS1 and LS2 both actuated, the bridge of station A, between the line conductors thereof, is effected by the production of a current by conductors 125 and 129 (associated with line switch LS2) and through conductors 226 and 229 of the local trunk line. Conductor 129 is connected to earth in the TC junction circuit by contacts of relays 116 and 117, and conductor 125 is connected to the battery in the main office through the contacts of relay 117 in the TC junction circuit, the relay 114 of the TC junction circuit, the contacts of the switching relay 102 from the line switch LS to the main office, and the line relay 101.

   Series relay 114 operates in this series connection with line relay 101 and closes a circuit for release cell 115, after which relay 115 places earth on junction release conductor 127 in order to maintain the junction line between offices occupied to the connector, A branch connection exists through the upper contacts of relays 119 and 120 to the retaining conductor
126, the retaining terra being thus extended by the contacts of the line switch LS2 to the release junction conductor 227 of the local junction line ... which keeps the relay 218 of the junction line actuated and the 'winding
204 of the line switch LS1.

   This operation of relay 115 naturally occurs before the connector is released, caused by the action of relay 218 which disconnects the trunk line talk conductors from conductors 219 and 221.



   In the main office, the operation of the line relay 101 results in that a free trunk line is selected in the usual manner by the line switch LS, this line switch being actuated by the magnet 103 to switch off.

 <Desc / Clms Page number 25>

 automatic operation under the control of the test wiper 105. When a free junction line is reached, the relay 102, which is short-circuited by the earth potential encountered by the wiper 105 during the operation of the ' line switch is no longer put on short-black and turns on ah series blind to the magnet of relatively weak resistance and establishes the connection to the wipers 104-106.

   The IOI line relay is disconnected and the connection is extended by the line relay of the associated selector which activates the associated release relay to earth the release junction conductor of the selector, which closes a holding circuit for relay 102 before lonto-acting relay 101 has or time to rotate.



   Relay 116 then operates by means of the lower reversing conductor, by its own contacts and those of relay 115 in series with the selector line relay, and locks itself to earth locally by setting the same. time in connecting the lower conversation conductor and removing the earth from the right section of it.



   In the branch office, the main switch is forced to advance in the manner described above when relays 307 and 309 have both fallen, and another free trunk is chosen leaving the established communication of the branch. line from station A to the main office by means of line switches LS1 and LS2 and the TL connection line.



   The subscriber of station A then dials the various digits of the number of the desired subscriber, after which the switching mechanism of the main office operates to complete the call in the usual manner.



   When the subscriber of station A replaces his receiver after the conversation, the main office connection is disconnected in the usual way and the series line relay II4 in the TC junction circuit drops out and opens the relay circuit. beration 115. The release relay 115 drops out after a slight

 <Desc / Clms Page number 26>

 interval and remove the earth from conductor 127, after which the occupancy lamp 153 is turned off, the line switches
LS1 and LS2 sa release and the interrupt relay 218 drops.



   Assume now that a local subscriber who does not have the right to make calls in the main office tries to make a call to the main office. For ease of explanation, it will be assumed that the line at station A has changed from the unlimited use category to the limited use category, by the removal of the jumper associated with the line switch spring which comes into contact with the fixed contact connected to the distinction switch 228. In this case, the conductor 228 is not earthed when the line switch LS1 is actuated when the receiver is removed, and the conductor 220 of the connector is therefore not earthed.

   Consequently,. when the number 0 is formed on the dial) relays 301 and
303 operating in series through the contacts 313, and the relay 303 extends the conductor 220 through the contacts of the slow-acting relay 308 still actuated and the switch contacts 321 to the progress relay 310. The relay 303 connects the earth to the earth. conductor 220 from the grounded conductor 223, passing through resistor 302, so as to operate relay 310.



   Relay 310 operates by means of resistor 302 and locks itself to conductor 370. When relay 308 then returns to initiate rotary movement, it transfers conductor 220 to the location of its upper armature. , to the rotating magnet 319 via the contacts of the relays 310 and 312.



   Rotary magnet 319, however, does not operate by resistor 302 and relay 310 remains energized giving the calling subscriber a busy signal as described above.



   The driver is released by the calling subscriber or by the device in time if the calling subscriber does not hang up.



   It will now be assumed that the TL junction line is taken in service in the main office by means of conductors 107-109 by a connector switch of the usual type.

 <Desc / Clms Page number 27>

 



   When this is done the connector places earth on the normal private conductor 108, which causes relay 102 to operate enough to force its top armature springs to snap out of socket with their rest contacts, but not enough to force the wipers to be connected, as a result of the usual mechanical arrangement of winding (not shown) between the armature of the IOI relay and the armature of the relay 102.



   The busy relay III, which is bridged between the junction line conductors by means of the relay contacts 115 and in series with the high resistance 110, is energized from the battery potential superimposed in the bell circuit ( not shown), so as to make the trunk line occupied in the branch office by the earthing of inverter 127, whether the connection is established to the trunk line during the ringing period or during the ringing period. silence.



  The high resistance IIO limits the flow of current to a value such that the bell interrupt relay xxx in the connector (not shown) does not operate.



   When the ringing current is launched in the conversation inverters of the TL trunk line by the turn-on connection, it activates the ringing relay II2 of the TO trunk circuit, the lower winding of which is bridged between oes conductors to the associated capacitor ,, the lower contacts of relay II2 and the lower contacts of release relay 115.

   While operating, the relay II2 closes at its upper armature a locking circuit for itself by the contacts of the relay IIS) at its lower armature, it withdraws its lower winding from the bridge of the conversation conductors, and at its armature lower internal it activates the relay II3 which establishes a second connection with the earth for the conductor 127. The seconda oonnection to the conductor 127 at the upper oontaots of the relay 113 is useful during the ringing period since it keeps this conductor 127 set to the earth without interruption ma-

 <Desc / Clms Page number 28>

 me if the -relay III oscillates under the effect of the ringing current.



   Another result of the operation of relay 115 is that it closes a circuit for the call lamp 152 at the attendant's board, at the location of its internal upper frame, and through the contacts of relay 118, and at its switchboard. lower armature it makes certain circuit changes so that the ringing interrupt operation, which is carried out subsequently in the connector. or controlled by means of a boole circuit without any local earth connection to the conversation conductors.



   When the attendant notices the on state of the call lamp 152, he removes the attendant telephone receiver, Figure 4, which is common to a number of junction circuits such as TC, which provides ground through relay 401 to conductor 137 and through the relay contacts to reoherohe conductor 136.



  The telephone talk circuit is bridged between the associated talk leads. The operator then actuates the combined ROK release and oonnection key specific to the TC junction hole to the right into the connection position, which extends the ground of the search conductor 136 towards the lower winding of the cable. connection relay 117, Relay 117 operates and locks itself, by means of its upper winding and internal upper contacts of relay 120, to the common retaining conductor 137. Guard relay 401, figure 4, operates then in series with the upper winding of the relay 117, figure 1, and disconnects the earth of the search conductor 136,

   this prevents the operator from actuating another connection relay than 117 until the operator disconnects his receiver by hooking or undoes the communication by folding the olef RCK to the left in the release position.



   The operator returns the key to normal after having actuated it momentarily, leaving relay 117 locked as mentioned above. It should be noted that with the relay
II7 activated, the reversing circuit is cut and the

 <Desc / Clms Page number 29>

 conductors 125 and 129 extending to the line switch LS1 are connected to common conductors 133 and 134, and that the conversation conductors of the main office are connected, at the location of the upper and lower frames of the relay., to common conductors 130 and I3I.

   With relay 113 being actuated at this time, conductor 131 is connected to the lower reversing conductor of the main office by means of the lower frame of relay 117 and the lower frame of relay II3. than
Referring to Figure 4, it can be seen / the common conversation conductors 130 and I3I are connected by the contacts of the operating keys of the dial DO and DI to the conductors 133 and 134 and that the connected conversation conductors are covered with a bridge formed by the impedance 402 and by the conversation bridge of the agent's telephone.

   The usual ringing interrupt operation is then carried out in the calling connector under the effect of the current flowing through the upper reversing conductor, through relay 124, through impedance 402 and the attendant's telephone in parallel and returning through the lower conversation conductor. At the same time, the usual bell interrupt relay of the socket connector in possession operates in such a way as to disconnect. The usual conversational current supply connections are substituted for the bell connections. The relays II4, 115, and II6 attract their armatures one after the other (as in the outgoing call described above) since the relay II4 receives current in series with the left section of the upper conversation conductor. .



   Another result of the operation of the connection relay 117 is that it operates the restraint relay 118 at its internal lower armature, after which the relay 118 operates and locks itself at the location of its lower inter- release armature. ne by means of the lower contacts of the relay / 120. At armature 141, the relay They prepares an oirouit for the line relay 209 of the line switch LS2, it prepares a circuit for the monitoring lamp 151 of the jonotion oirouit to its upper armature

 <Desc / Clms Page number 30>

 re, and it extinguishes the call lamp 152 at its internal upper armature by removing the bypass of the resistor associated with the armature 122 of the connection relay activates 117.



   After having ensured that the equipment of his station is connected to the TC junction circuit in the manner indicated above, the operator learns the desired number of the calling subscriber and then folds his dial key DI, which disconnects the impedance 402 and the extended talk leads 130 and 131 from the main office of the talk leads
 EMI30.1
 P'I'0} one: és TSe5 and 104 C112 1) \) {'(: 111 dn 1) rnnnIH111nt, qn J; 1j gp: mt Bf1n telephone bridge between conductors 133 and 134 At the upper contacts of the key, the earth is placed on the conductor 132, which closes a circuit by the armature I4I of the relay 118, the lower contacts of the relay 119, the conductor 128 and the interruption contacts of the line switch for the line relay 209.

   The relay 209 attracts its armature and activates the line switch to grab a trunk line, for example the trunk line comprising conductors 226-229. Under the effect of the operation of the line switch LS2, the winding 210 bridge interrupt is energized as a restraining winding by means of the associated contacts of the line switch from the earth placed on conductor 126 in the TC junction circuit by the upper contacts of the relays
 EMI30.2
 119 and I? 0 s.

   From the ooiiduntniir min il tf1rro T? 7, Another result of the operation of the line switch is that the grounded conductor 126 is extended by the fixed contacts of the line switch to the release junction conductor 227, which makes the junction line occupied in the fixed contact row of the main switch and forms a circuit through the conductor 223 and the relay contacts 307
 EMI30.3
 UL L 300 of dtJ1itltJd LüLlL '1 lJOUl.' 11 t'ELtaly 16 Ü6J11bl'1 ':; gÙ iLi uùi <iniuLcsLeur main by means of conductor 225.

   As the starting relay is rigidly adjusted as in usual practice, no
 EMI30.4
 does not operate at r-oo moment as a result causes its flow to not -oe moment as a result of the fact that its circuit is

 <Desc / Clms Page number 31>

 , open at the contacts of relay 307 which is energized under the effect of the operation of relay 306 as a result of the line relay 305 being energized by conductors 219 and 221, by means of the attendant's telephone which is now connected to conductors, incoming conversation 125 and 129 as mentioned above. In the event that difficulty is encountered in preventing the starter relay from energizing, its circuit can be changed to include an additional pair of normally closed contacts on the delay relay 201.



   The operator then forms the digits of the desired number on the dial, after which the connector is placed on the line of the called subscriber, the line of station A for example) in which case station A receives the signal by the current of bell, after which the line switch LS1 is actuated by means of the connector wiper 324 and by the brone 253 when the bell interrupt relay 309 operates.

   Ground is placed on interrupt conductor 222 at the upper internal contacts of bell interrupt relay 309 to actuate relay 218, Figure 2, through the main switch interrupt wiper, but the relay 217 of the battery supply is not actuated at this time due to the fact that the resistor 320 is interposed in the circuit due to the prior operation of the relay 301 by means of the conductor 220, from the connection of battery supplied to the contacts of the LS2 line switch for this purpose. Relay 301 is then latched by its own contact and the upper internal contacts of relay 306 to the associated resistor and its initial circuit is open.

   The result is that the battery supply for the conversation arrives at the station called A from the main office instead of coming from the branch office, which is in accordance with well-established practice.



   In the event that the operator discovers, during the establishment of a local communication, that he has made an error in the operation of the dial or when he wishes for any-

 <Desc / Clms Page number 32>

 the other reason free the connector and start again, he presses the RIK release key, figure 4, which opens the line circuit at the location of the lower contacts of the key and earths the conductor 135 to the location of the upper contacts of the key, so as to actuate the release relay 119. Figure I, through the armature 123 of the relay 117. The relay 119 disconnects the earth of the normal private conductor 126 of the line switch, at the location of its upper frame, and it opens a point of the line relay circuit at the location of its lower frame.

   When the key is released, the returned line switch returns to normal operation and the connector is prepared for operation as previously explained.



   After dialing in the local number, the operator returns the DI key to normal, which again links the two segments of the conversation circuit together so that subscribers can converse.



   After having listened in the line, either before or after returning the dial key to normal, to be sure that the desired subscriber has answered, the operator hangs up the receiver of his telephone, which opens the locking circuit of the upper winding of the connecting rail 117 of the TC junction circuit. Relay 117 drops out and connects the two conversation sections together and disconnects the operator's conversation leads. At its armature 122, relay 1117 opens the circuit of relay II2, after which relays II2 and 113 drop out.

   Relay III is now bridged between the talk conductors through the energized relay contacts 118 and the unactivated relay contacts 117 and 113, so as to maintain the response monitoring state in the main office after the branch office subscriber hangs up, This bridge acts, in the event that the operator hangs up immediately after the operation of the dial, to keep the / branch office connector activated until it is

 <Desc / Clms Page number 33>

 either released under the effect of the operation of the device on time or under the action of the called subscriber. Relay 118 remains latched by its own internal lower contacts and the lower contacts of relay 120.



   When the called subscriber hangs up his receiver at the end of the conversation, the line relay 114 drops and opens the circuit of the release relay 115, which relay drops and lights the monitoring lamp 151 through the contacts of the relay 118. When the The subscriber calling on hook, the connector in service becomes free (unless it is of the type released by the last participant), which allows relay 102 to return to normal and to connect the line relay. IOI of the line switch. Line relay 101 does not operate at this time ;, even though relay III is bridged between the conversation conductors of the junction line, due to the fact that there is no operating earth connected to the lower trunk conductor.



   When the operator notices the on state of the monitoring lamp, he returns the RCK key to the release position, which activates relay 120 and releases relay 118. Line switches LS2 and LS1 become free and relay 218 drops out when the earth of conductor 126 is removed at the upper contact of relay 120.



  The entire connection is now disconnected, and the lage included in it is ready to be used for further communication.



   It will now be assumed that the subscriber of station A wishes to converse with a subscriber at the main office and that he wishes the agent to establish the call and let him know when it is ready. In order to get in touch with the agent, the subscriber of station A dials the number assigned to one or the other of the "information" trunk lines, figure 4, after which the associated line switch at this . trunk line is put into operation to connect this

 <Desc / Clms Page number 34>

 line to the calling line.

   If we assume that the number of the information junction line 1 is formed on the dial and that this junction line is free at this time and is therefore taken in service, the call lamp associated with it is operated by means of the private normal conductor in parallel with the line switch bridge interrupt winding, corresponding to the winding 204 of the LSI line switch.



   When he notices the on state of the call lamp, the operator responds by momentarily activating the response key AK associated with relay 403, after which relay 403 operates by means of the telephone hook-switch contacts. attendant and by means of the contacts of relay 401, and locks itself
 EMI34.1
 on norio confessed on rolaio. Lo rolaÍrJ / 10J d (, 00111100tO lo ooiicluatour normal deprived of the call lamp and instead connects it to the earth, although this last operation is not essential since the connection is maintained by the supply relay junction line battery in service, corresponding to battery supply relay 217, figure 2.

   At its upper and lower contacts, the relay 403 connects the conductors of the intelligence junction line to the operator's conversation circuit, which allows the agent to converse with the calling subscriber. After being informed of what the calling subscriber wishes, the operator places the receiver back on the associated telephone, after which the relay 403 drops. The communication established from the line of set A is released when the calling subscriber hangs up.



   In order to complete the connection to the desired subscriber at the main office, the operator removes the receiver from his telephone and observes the busy lamps associated with the various trunk circuits such as the TC trunk circuit, and fold down the connection key of a free circuit or the TC junction circuit for example; after which the relays 117 and They operate in the manner described above and the relay 117 respectively connects the two sections of the junction line to the operator's device by means of the conductors 130 and / 131 and of

 <Desc / Clms Page number 35>

 
 EMI35.1
 conductors 133 to 134.

   When the bridge between Ina oonduotouro X3p and 131 is placed between the connecting conductors extending to the main office, there is an earth encountered by the conductor 131 by means of the oontaots of the actuated relay 117 and the contacts of the non-actuated relays. Aotées II3 and 116. This earth extends through conductor 131 and through impedance 402, figure 4, to the upper junction conductor) through conductor 130, to actuate line relay 101 of the line switch LS in the main office, after which relays 114 and 115 are activated as before. When a free selector is taken into service by the LS line switch, the earth arriving through the lower coil of the selector line relay is placed on the lower conversation conductor of the TL junction line. ,

   which activates relay II6 by means of its own internal lower oontaots, contacts of relay 113 and armature 142 of relay 118. When operating, relay 116 locks itself in the energized state independently of the lower conductor. and connects the lower conversational conductor of the TL junction line to the lower left conversation conductor 129, at the same time removing from the lower conversational conductor the local connection with the earth.



   To be able to operate the switches of the main office in order to establish communication with the called line, the operator moves his key DO for maneuvering from the dial to the outside, which connects the conductors 130 and 131. to his telephone and disconnects from it the conductors 133 and 134. After that, the agent manipulates the calling device of his telephone in oon-
 EMI35.2
 oorGlano9 + v <io the digits of the desired number oe which provoluq 1 establishment of communication in the usual way to the desired line. If it is assumed that the called line is free and that the subscriber answers the call, the agent lets him know that the subscriber of extension A wishes to converse with him and invites him to wait a moment while 'it completes the communication.



  The operator then releases his operating key DO from the dial

 <Desc / Clms Page number 36>

 towards the outside, activates its dial control key DI towards the inside, which forces the line switch LS2 to operate in the manner described previously and it forms the number of the subscriber of the set on the dial. A, after which the communication is extended to this line as described above. It should be noted that the impedance winding 402 as-
 EMI36.1
 :: Oü: L6 at the key de ücWj.Z't3Yl figure 4, is} Jlao0 between conductors 130 and 131 so as to maintain communication from the main office while the operator dials the local number of the subscriber of set A.

   From this point on, the communication is handled as described above in connection with handling an incoming call.



   For the explanation of the code calling equipment shown in Figure 5, it should be noted that in private establishments it frequently happens that there are a number of employees who are called very often and who are forced, by their work, to be often far from their phone. To transmit calls to similar people, we imagined the code calling device. How the code calling device operates in the present system will now be described.



   It will be assumed that a local subscriber has called, without being able to reach him on his telephone., A subscriber to whom a code is assigned, and that he wishes to use the calling equipment of code :, the calling subscriber withdraws its receiver and forms on the dial the code call number 30 followed by the particular code number assigned to the person in question. If it is assumed that the calling subscriber is that of station A, figure 2, the removal of his receiver has the effect of the operation of the line switch LS1 to seize a trunk line, for example that shown above. - sin.

   The common connector shown in figure 3 is prepared for operation in the usual manner, it is lifted up to the third stage of fixed contacts, when the first digit 3 is formed on the dial and it is rotated until taken with the tenth series of fixed contacts of the third stage, figure

 <Desc / Clms Page number 37>

 5, when the second digit 0 is formed on the dial. The contacts associated with the resistor 320 and designated by "30" and "00" are separated at this time by the usual arrangement of the blade on the switch shaft, which introduces the associated resistance 320 into a connection with the conductor of the switch. switching 222, so as to prevent subsequent operation of the battery supply relay 217.

   If it is assumed that the code call number is free at this time, the switching relay 312 of the connector generates its pull in the usual way by the test trotter 323 and by the winding. LS4 line switch bridge interrupt. Under the effect of the attraction of the relay 312, the usual latch circuit is closed for the lower winding thereof from the conductor 370 and a parallel circuit is then closed for the lower winding. the bell interrupt relay 309 by the associated cam springs designated "30" and "00".

   The relay 309 operates and connects the earth to the wiper 324, which closes a circuit passing through this wiper and the fixed contact on which it rests, for the attraction winding of the line switch LS4, the line switch LS4 is then actuated to extend a connection to the trunk line to which line switch LS1 is connected. Interrupt relay 218, Fig. 2, is actuated in the usual manner, but marginal relay 217 is not actuated due to resistor 320 being introduced into the circuit at this time by the springs. associated cam, as indicated above.



   The line relay 501 of the selector of this CS code then operates by means of the associated conversation conductors.
 EMI37.1
 ot dos oc) ndl1c'Lourn r0nr,; l5calc, r.mto do lu 11plO cln jouobion or u.aa. ge by line switches LS4 and LS1, and by means of the line from station A, and it closes a circuit for the associated release relay 502 which operates and places the earth on the normal private and trunk conductor associated, so as to keep actuated the two line switches and the

 <Desc / Clms Page number 38>

 interrupt relay 218. The terra is connected to this conductor before removing the earth from it by means of the wiper 323 of the connector. Relay 502 also prepares the code selector for operation at its bottom frame.



   When the calling subscriber dials the code figure assigned to the particular person desired, line relay 501 drops off a corresponding number of times and activates the aid.
 EMI38.1
 Ill 'llL roLeat, iW of the a6lautour (if) soda aliticlitei fola thatll roLuotbo. The relay 503 operates in parallel with the rotating magnet when the first pulse is saturated and since it is slow acting it remains actuated during the series of pulses. When relay 503 drops out at the end of the digit, it closes a circuit through the contacts of relay 504 and through the out-of-normal contacts 506 to start the CG code generator motor and to
 EMI38.2
 supply the borro by Ion ooutaota do () 1. \! fW from the gouuratour to the various fixed contacts.

   The motor then actuates the cam contacts to produce their respective codes in the usual manner and the chosen code is supplied by the wiper 507 to the code rings via the contacts on which the wiper 507 is located.



   If we assume that the called party does not answer,
 EMI38.3
 the subscriber alrpf; lazlt replaces the receiver, after which the line relay 501 drops out, which is followed shortly after by the de-exploitation of the relay 502 to allow the release of the communication when it removes the earth of the releasing junction conductor associate.



  When the desired person hears his code which is spread throughout the installation, he goes to the nearest telephone and after having removed the receiver and obtained the command of the connector in the usual way by actuating the telephone line switch. in use, it forms the code response number "39" on the dial, after which the connector establishes the oonnection with the line switch LS3. Switching relay 312 of the connector is actuated at this time in / series aveo

 <Desc / Clms Page number 39>

 the LS3 bridge interrupt winding and connects the wipers 322 and 325, which applies the ringing current to the line conductors of the LS3 line switch.

   The relay 504 ;, FIG. 5, then energizes in series with the bell interrupting relay 309 of the connector because of its lower winding being bridged between the bypass conductors, and it closes a latch circuit for itself to the earthed conductor associated with. the location of its upper internal contacts, at the same time disconnecting its upper winding from the, .bridge between the inversion conductors and. by removing the earth from the starting conductor of the coda generator, as well as by energizing the release magnet to return the slider 507 to normal. The output of the release magnet is opened to the out-of-normal contact of the switch when the slider 507 reaches its normal position.



   In the connector, the bell interrupt relay 309 energizes at the same time as the relay 504, figure 5, and locks itself at the location of its internal lower frame and it performs the functions described oi above, including the grounding of the interrupt conductor 222 to cause the operation of the interrupting and battery supply relays of the connection line in use, corresponding to relays 218 and 217. Figure 2, in order to isolate the junction line and to connect a current source supplying the transmitter.



   The conversation then takes place between the line of set A and the line used by the called subscriber to answer the code call) the switchgear which is included in the call being the line switch LS1 which is plunged to the trunk line comprising conductors 226-229, the line switch LS4 which is plunged to the same trunk line, the line switch LS3, and the response line linen switch which is plunged, up to the marna jonotion line as the LS line switch,

 <Desc / Clms Page number 40>

 
After the conversation is terminated, the line switch LS3 and the line switch of the answering line are both released when the answering subscriber replaces his re-pass.

   which allows the hold and supply relay of the dry battery corresponding to the relay 217, figure 2, to drop out and remove the earth from the associated release junction conductor.



   When the subscriber of set A replaces his repeater, line relay 501, figure 5, drops out and again closes an opening for the rotating magnet and relay 503 in parallel, by opening in parallel. at the same time the circuit of the slow-acting release relay 502. A moment later, the relay 502 drops out and opens the circuit of the rotating magnet and closes the circuit of the release magnet, after which the wiper 507 is returned to its position. normal position. Relay 502 also removes the earth from the associated release junction conductor allowing line switches LS4 and LS1 to return to normal, and allowing interrupt relay 218, Figure 2, to drop.



   The branch office has been described above as having a capacity of one hundred lines. The connector circuits shown in Fig. 3 have instead been arranged so that they operate in connection with a modified arrangement of fixed contacts when a private automatic office of this nature is established for a capacity not required. exceed 50 lines.



   When the desk is set up to have a final capacity of 100 lines, the connector of Figure 3 is provided with a row of fixed 400-point contacts in two sections each similar to the group of fixed line contacts. a connector switch with the aid of which conversation communications are supplemented. However, when a private automatic office is installed in a situation in which it is probable that the required capacity will never exceed 50 lines, a fixed contact group with 200 contacts in one section only can be installed) in this case. the two sets of / walkers are placed closer to each other so that when the set

 <Desc / Clms Page number 41>

 from the bottom is in front of the first stage of fixed contacts, the top series is in front of the sixth stage.

   The lower series of wipers thus used the lower half of the stationary contact group while the upper series of trotters used the upper half of the stationary contact group.



   In this case, only the first five chines are needed and it is therefore convenient to assign the digits 2 to 6 rather than the digits I to 5, due to the fact that the digit 1 is frequently undesirable because of the danger. preliminary pulses and faulty line conditions giving the effect of dial formation of the numeral 1 before dial operation begins. Conditions which are well known and will generally be understood. The series of wipers are sequentially placed in a position to come in front of floors 1 and 6 of the group of fixed contacts when the number 2 is formed on the dial and do not prolong a communication towards the conversation uonduoteurs of any called line if they are lifted only by one step.

   To this end, it is foolishly made that the wipers 322 and 325 of the connector are the wipers of the lower series and do not come into engagement with any fixed oantot while the wipers 323 and 324 of the upper series come into engagement. with the fixed contacts of the fifth floor, that is. the upper stage of the line contacts, and whose contacts are therefore not in connection, being left dead as are the contacts of stage 0 of the wipers 322 and 325 in FIG. 3.



   In the event that the arrangement is used with outgoing junction lines which require the line contacts of the fixed contact group to be connected) the wipers 322 and 325 would be placed in the upper series and the wipers 323 and 324 would form the series lower. In this case, the wiper 323 would not encounter a fixed contact when the first digit is "1" and the switching relay 312 would not operate to connect the wipers 322 and 32.

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   For many years it has been the common practice to assign the digit 0 to trunk lines exiting a private automatic office and for this reason it is desirable to assign the digit 0 even in the modified private automatic office. 50 lines described above, although the dial formation of the number 6 is sufficient to cause the seizure in service of one of these junction lines. It should be noted a. Figure 3 shows that the vertical magnet circuit 317 contains contacts of the relay 303 which is actuated by the associated shaft springs 313 of the "0" stage.

   When using the 100-line private automatic office the lower contacts of relay 303 do not perform any useful function, but when using the private automatic office modified as outlined above, the springs 313 are established. so as to operate when the shaft is lifted six advancements, after which relay 303 operates and opens the circuit of the vertical magnet, which prevents the rubbers from advancing above the level of the line of outgoing junction.



   CLAIMS.



   - - - - - - - - - - - - - - -
I) - A telephone system comprising conversation connections established by means of digital hon switches associated respectively with the calling and called parties in which these switches are arranged so as to receive their advancement together by a common control mechanism.



   2) - A telephone system comprising conversation connections established by means of non-digital switches with the calling and called parties respectively, in which these switches comprise line switches of the plunger type, controlled by a common main switch.

** ATTENTION ** end of DESC field can contain start of CLMS **.


    

Claims (1)

3) - A telephone system employing preselector line switches to connect a calling party to a first digital switch, in which all line switches normally choose the same trunk line and <Desc / Clms Page number 43> connections are completed by the fact that the line switch of the called partioipant is activated under the control of a digital switch to take service of the trunk line by means of which the calling partioipant has established the connection. . 4) - A telephone system - in which incoming and outgoing calls are both completed by means of the same non-digital switch which is activated in each case without performing a hunt operation. 5) - A telephone system with established connections under the control of a device operating under the effect of pulses and temporarily associated with the call communication, in which a device in time activated during the call. taken in service of the device operating under the effect of pulses is intended to cause its release after a determined time in the event that it has not been fully energized by pulses. 6) - A telephone system comprising connections established under the control of a device operating under the effect of pulses and temporarily associated with the poll communication, in which the production of the signal for the desired participant is carried out from the device operating under the effect of pulses. 7) - A telephone system with connections established under the control of a device operating under the effect of pulses and temporarily associated with the polling communication, in which the production of the signal for the desired participant is carried out from the pulse-functioning apparatus and is interrupted after a determined time, after which the pulse-functioning apparatus returns to common use. 8) - A telephone system comprising a device operating under the effect of pulses, arranged to handle the traffic coming from a certain number of trunk lines. <Desc / Clms Page number 44> in which all cases trunk lines are normally connected to this pulse apparatus, a trunk line by which a call has been established being disconnected from oelui-oi, when the connection is complete. 9) - An automatic telephone system in the bay under the effect of a fault reproducing the call conditions on a line, the line is connected, after a determined time, to a trunk line independently of a digital switch . 10) - A telephone system comprising a ringing current supplied to the line of the desired participant from the final digital switch, in which the application of the ringing current is made for a determined time and according to a determined code which is the same for all participants. II) - A telephone system comprising a current of signal from the supplied busy signal / of the final digital switch, in which the application of the busy sound is made for a determined time, after which the calling party is disconnected. tee of the digital switch. 12) - A telephone system according to claim 2, in which the main switch is established so as to keep all switches free in front of a trunk line through which a call has been initiated until the connection is completed . 13) - A telephone system according to claim 2, wherein the divers are intended, upon release, to automatically recover, alignment with other free divers. 14) - A telephone system according to claim 13, wherein the potential to effect the operation of a line switch on an outgoing call is applied after a slight delay, so as to prevent the line switch from being activated. new before it has been re-aligned in front of the same line of jonotion as the other Libros divers. <Desc / Clms Page number 45> 15) - A telephone system according to claim 14, in which the delay is obtained by the intercalation, in the ouit, of the high resistance winding of a relay slow to produce its attraction, which relay, when (its operation) bypasses this winding by means of a low resistance winding. 16) - A telephonic system according to claim 1, 2., 3 or 4 in which battery power is supplied to both the calling participant and the called partioipant from the same relay. 17) - A telephone system as claimed in claim 16, wherein for office communications the battery power is supplied from oelui-oi. 18) - A telephone system according to claim 16 to or 17, wherein the battery supply relay is / set marginal and is not activated during calls from the main office to connect to the conversation leads. 19) - A telephone system according to claim 1, 2 or 3, including provisions for calling by code of certain participants, in which the code calls are completed by means of four non-digital switches and two oirouits jonotion, the battery supply relays of the two jonotion lines being separated by capacitors. 20) - A telephone system according to claim 3, 5, 6, 7, 10, or II, wherein the dial operation sound is supplied from a sound generator associated with the digital switch and intended to be put in aotion when the switch is taken in service. 21) - A telephone system according to claim 3, 5, 6, 7, 10 or II, in which the busy sound is supplied from a sound generator, associated with the digital switch and intended to be switched on. action when the switch is taken in service. 22) - A telephone system according to claim 20 or <Desc / Clms Page number 46> 21, in which a continuous sound is used as the dial maneuver indioation while the same sound with interrupts is used as the oupation signal. 23) - A telephone system according to claim 22, wherein the busy sound and the dial sound are supplied to the connector through the same conductor, 24) - A telephone system according to claim 4, wherein the non-digital switch is a plunger type line switch whose operation for outgoing calls is effected by closing the calling loop while for incoming calls it is carried out by means of a wiper of a digital oommutateur under the effect of pulses formed on the dial by the calling party. 25) A telephone system as claimed in claim 6 or 7, wherein the digital switch is released from the called party's answer if it is associated with the call at that time. 26) - A telephone system as claimed in claim 8, in which provision is made to prevent a communication from being initiated by means of any of these trunk lines as long as the apparatus operating under the line. pulse effect is associated with a calling participant. 27) A telephone system according to claim 8, wherein a chain circuit extending through all line switches which have access to the trunk group is for preventing the operation of more than one switch. line at the same time., 28) - A telephone system according to claim 27 in which this chain channel also extending to the operating device under the effect of pulses and is open at the location thereof as long as the the apparatus in question is in use. 29) - A telephone system according to claim 8, in which the disconnection of the trunk line of the device operating under the effect of pulses is effected by a re <Desc / Clms Page number 47> interruption leave excited by oelui-oi, 30) - A telephone system according to claim 29, in which during operation of the interrupt relay the excitation circuit is transferred to a battery supply relay which then locks between the reversing conductors and provides a holding circuit for the interrupt relay. 31) - A telephone system according to claim IO, in which the code comprises a short ring to indicate the arrival of a call, followed by a long ring to indicate the desired telephone in the case where several telephones are placed. close to each other. 32) - A telephone system according to claim 10 or II, wherein the switch is itself released at the expiration of the determined time. 33) - A telephone system according to any one of the preceding claims, in which some subscribers have the right to make calls out of the office while others do not, the distinction being made at home. location of the digital switch with appropriate connections at the location of the line switch. 34) - A telephone system, substantially as described above and as shown in the accompanying drawings.