BE332977A - - Google Patents

Description

       

   <Desc / Clms Page number 1>
 



  IMPROVEMENTS TO SYSTEMS FOR AUTOMATIC TELEPHONE CENTRAL OFFICES.



   This invention, which relates generally to telephone systems, relates more particularly to systems for automatic central offices capable of communicating with small rural offices sometimes left unattended.



  However, several facts of the invention may apply to other kinds of central offices than those mentioned above.



   In the arrangements described, means have been provided for obtaining forced restores to the normal position of local devices when this becomes necessary for any cause. For example if a subscriber removes his receiver from the hook switch without operating his dialing disk, the cord circuit chosen for this call initiation can be returned to the normal state after a certain time. Likewise, if a subscriber calls forgets to hang up his receiver at the end of a conversation, and after the called subscriber hangs up his, a forced reestablishment of the post envisaged takes place after a desired time interval.



  If a permanent closed circuit is created on a link line, that is to say on a junction line bringing together two similar secondary offices such as two rural offices, the devices associated with this line for the extension a call can be rowed

 <Desc / Clms Page number 2>

 born to normal. It is obvious that the means provided here can also be used in the case of a line brought into a call condition due to an error. In the latter case, the devices connected to the faulty line are brought back to rest.



   Arrangements of the kind described are of very great importance for desks of the type mentioned above, that is, for desks left unattended. In automatic offices with a relatively large capacity and where continual over-valuation is assured * it is preferable to arrange the calling lines in such a way that if a permanent closed circuit is created on one of these lines, it remains connected to the switching device so that upon operation, the faulty line can be immediately determined from an alarm signal. On the contrary, in an office left unattended, such an arrangement would cause a relatively large number of common devices to be taken out of service.



   By the means provided, any line can be taken out of service when the wing is not in good working order.



  For example if a permanent call condition is created on a line due to an error or for some other reason, this line is taken out of service after a determined time interval. Likewise, if a link line is placed in the same conditions, disconnection devices come into action to put this line out of service. To this end, when a local connection circuit has been occupied for a certain period of time, changes occur in this circuit which cause a special disconnection switch to search for the faulty line. This line is provided with a certain potential applied by the lead circuit to a terminal of the panel of the corresponding seeker switch.



  Each line, either a link line or a subscriber line, is provided with an additional relay which is blocked through the circuit of the line when it is energized by the disconnector switch, while placing this line, in a occupancy condition. When the disturbing closed circuit is broken, or when the fault is

 <Desc / Clms Page number 3>

 removed, the relay is neutralized and the line is again in a condition required to enter service.



   The same device can therefore be used for link lines and for subscriber lines, but an arrangement is provided to make the link lines unusable at both ends. Thus, when a permanent closed circuit is created on such a line, maneuvers take place at the arrival end to render this line unsuitable and to release the corresponding equipment. At the same time a signal is transmitted to the remote or originating end to take this line out of service.

   The calling line, connected to the trunk line at this end, is then subjected to a forced restoration by means of appropriate devices.
If the permanent call condition on a link line results from a fault created on the subscriber line connected to it, that link / link line is restored to working order after it has. been disconnected, while the subscriber line is subject to forced reestablishment as well, as stated above. These various operations are carried out successively and automatically.



  Thus a permanent closed circuit is created on a link line as a result of the disconnection of this line at the incoming end and the reestablishment of the associated cord circuit. The signal, previously mentioned and transmitted at this time on the trunk line, immediately causes the reestablishment of the calling line at the originating end, and creates the condition of a permanent call at that end. If now the trunk line is in working order, the disconnection arrangement at the terminating end is broken, and the call created at the originating end ceases.

   The trunk line can then be used again, making this time the subscriber line on which the original closed circuit took place, is seized by a local cord circuit in the ordinary manner.



  Unless this closed circuit is broken within a specified time, the local cordon fired bus disconnects the line as described above. On the contrary, if the trouble is from the trunk line, the call created at the originating end causes

 <Desc / Clms Page number 4>

 connecting a local cord circuit with this trunk line. After a determined time interval, unless the disturbance has ceased, the connecting line is also disconnected at the outgoing end by means of the same disconnection device as that used in the other cases.



   The link line is arranged so that the operations digitized above can be performed in the desired order, resulting in additional count signals transmitted over the line, either for single action or repeated counter. A full description of the connections for line relays, disconnect relays, and signaling relays, which are circuited across the line at the outgoing end, is given below.



   One of the facts of the invention relates to the realization of an improved arrangement making it possible to transmit a signal to the surveillance office, when necessary. This arrangement is such that the signal is made effective regardless of whether it is received by a manual office or an automatic office, and that it clearly indicates where the disturbance to communications is coming from. that is to say the automatic rural installation trans putting the signa.!. Other means are to end a local call sent to the office. or from the office, if all lines are busy, so that the mentioned supervisory signal can be transmitted to the office.



   The device used to determine the time intervals which elapse between the various stages of a connection, also serves to transmit the said signal to the central office. For example the time switch, used to reassure the interval after which the disconnection must take place, also serves to transmit a signal to the main office, if this is deemed necessary. This time device additionally serves to break a call between the local office and the main office in order to allow signal transmission.



     The invention is better understood from the following description

 <Desc / Clms Page number 5>

 based on the attached drawings. On these, fig. 1 shows schematically a local connection circuit for an automatic rural installation, figure 2 shows the common ringing, auditory signal, and supervision circuits for this office, fig. .3 relate to a link line connecting two rural automatic offices of the kind shown in the other figures; FIG. 4 relates to the disconnector switch and to these associated circuits for the case of a rural automatic office in which no link line is provided; Figure 5 relates to a disconnect switch for an installation in which connecting lines are provided;

   FIG. 6 concerns a small modification made to the local connection circuit for use with the lines of a private office annexed this circuit replacing the circuit shown in fig.l, for all the lines except the last d 'an annex private office.



   Figure 2 should be placed below figure 1, st figure 4 or 5 should be to the left of fig. 2. Figs.3 and 6 must be considered separately.



   According to fig.l, when the subscriber of a substation removes his receiver from the switch hook, the line relay Lr is energized a. through the SL circuit, causing the Zr relays to be energized and
Cr Terminal c of the line finder panels is connected to one of the windings of the Cor cutout relay. The Gold relay completes, using its armatures, a circuit for the line finder's step-by-step electromagnet SM: battery, contact D of the combiner, protective resistor, electromagnet SM, contact switch of the latter ', Cr contact 1, BJ disconnector jack, Tr resting armature, and earth. The line finder is working.

   When the calling line is reached, a circuit is closed: earth, resistance, contact 1 on the left of Or, relay Tr, jack BJ, upper left and lower right contacts E, armature at rest of Vr, brush and terminal c , armature at work of lr, relay Cor, and battery. This Cor relay is shunted by a non-inductive resostance. When the Tr relay energizes, SMis neutralized, and the line finder stops. The

 <Desc / Clms Page number 6>

 Si- relay is excited in series in the circuit of SM, and Tr, attracting its armature, closes its blocking circuit independent of the contact of Cr. The Cor relay, attracting its armatures, maintains its connection with terminal c, while the line relay is disconnected.



    Ir, Zr, and Cr, are successively neutralized, but only after a sufficient time for the Sr relay to block through a circuit passing through the Nr relay. In the case of a double test, operation (the l One of the test rails places the resistance of this one in parallel with the other relay which is neutralized.



   The windings of the step relay Ir are connected to two contacts of Sr and to brushes a and b of the calling line. On being called up, Ir closes a circuit for the left winding of the slow reset relay Dr, which, when energized, provides at its working contact a direct connection with the brush c for the relay Tr This circuit is independent of contact E which is open for position two of the combiner. Closed circuit: earth, armature working with Sr, contact A, switch contact of the SSM combiner, relay Br, and battery.

   The Br relay energizes and closes a circuit for the SSM electromagnet. The combiner takes a step forward, finds the same closed circuit for position 1 1/2, and goes to position two! The lant Ur reset relay is energized: earth, contact B, lower left contact of C, relay Ur, low resistance winding of Tsr (fig. 2), and battery. The Tsr relay establishes a circuit for hearing signal. The Ur relay, attracting its internal fittings, connects the auditory signal to the cord circuit through two high resistances. the calling subscriber causes the sending of the first series of pulses. For each pulse, the Ir relay is neutralized.

   Closed circuit: earth, contact B (upper left), armature at rest ce Ir, resistance, Fr and Ar relays, and battery. The Fr sensitive relay operates in accordance with the pulses, while the slow recovery Ar relay keeps Br energized. This is not neutralized as long as the series of pulses takes place, and the stepping relay

 <Desc / Clms Page number 7>

 keeps its frame at work for a longer time. Circuit.
 EMI7.1
 closed: earth, armature at work of Fr and at rest of Xi, electromagnet SM1 of the selector, and battery.

   Closed circuit: earth, armature
 EMI7.2
 at rest of Jr, switch contacts of SM 2 and SM11 armature at work of Fr, right winding of Dr, relay Fur and Are and battery. ' The Fr and Dr relays are thus energized all the time
 EMI7.3
 that slltli gets excited, until it opens its switch contact. This ensures that Ir closes its normally-open contact for a sufficient time to energize the sensitive relay Fr. The movement of the selector is ensured, regardless of the time taken by the stepping electromagnet to operate, and the slow reset relay. Ar is more apt to neutralize itself since it receives current at each pulse only for a minimum time, regardless of the condition of the line.



  This arrangement allows the Dr relay to remain energized for a determined time interval, regardless of the time that the relay
 EMI7.4
 Ir keeps his working contact open. Di plus it ensures a very stable periodic movement circuit, which avoids the need for having an Ar at relay, particularly slow recovery, and which allows this relay to open its circuit in a comparatively short time after the last impulse. This saves t (: mps ntr the series of pulses for the operation of the switches.
 EMI7.5
 The brushes of the switch SIw.l, stop in a position corresponding to the first series of pulses, and when Ar is neutralized, Br opens the SSM circuit.

   The combiner goes to its 2 1/2 position. The circuits¯ provided in positions 2 1/2 and 3 for energizing relays Vr, Xr t Kr, when required, or for
 EMI7.6
 extend ur. call to a trunk line going to a main central office, are similar to those described in our patent 318,727 of June 21, 1924, a complete description of the operation of the lines is given below.



   Note that the Ur relay is now energized for the 2 1/2 position of the combiner, and when its circuit is open, it
 EMI7.7
 keeps the conductors of the brushes e 2 and f3e broken for a sufficient time for the combiner to leave its, position three. Of this-

 <Desc / Clms Page number 8>

 
 EMI8.1
 In this way, if Kr is excited, no snapshot takes place on the line on which the switch stops. ¯ As a result of the combination of the operation of the relays Xr, Vr, and Yr, SUL or SM is brought to one of the normal positions from which, in response to the pulses
 EMI8.2
 units, I? switch moves to the. ligna requested.

   In view of the different distributions of the combiner contacts, it should be noted that in the case where the relay Br is maintained on a link line or call "0" for position three of the combiner, its circuit is: closed through the frame to work of Sr, contact F, and the frame
 EMI8.3
 at rest of Jr. For such a position, the winding of Jr #fc con; connected by contact C to the starter relay of the link line or Itolt appol. The complainer Jr is therefore not excited.



   If the switch remains in its soft position for thirty minutes. seconds, the bead circuit is automatically released by means of the Er relay and a common time arrangement, shown in fig. 2. This arrangement is described below in connection with this figure. It suffices now to mention that the relay circuit Er is closed through the contact B (upper right), the armature at rest of Pr, the winding of Er and its compound contact.
 EMI8.4
 and a closed contact to the common arrangement of fiv.2 which is in its rest position or if this device is in action, switches to many contacts at given time intervals.

   Relay Er can therefore only be energized when this time switch passes over such a contact. The relay circuit is then closed, and this relay prepares
 EMI8.5
 a circuit which, after a certain time..9xel'ce its action if the ref- ': lads Er is not neutralized. This circuit marks the planned line! a potential f.1Ciximum on the. terminal d, while the arrangement commu- nicates in itself a deoonnector switch which searches for terminal '), individual d. During this time interval no link lines or 8j,) pfll "0" will be created, and no "C" switch can perform a search.

   The disconnect switch, en-! looking for this terminal, activates an individual relay which is blocked on the. line, disconnects the line relay, and releases the cord circuit.

 <Desc / Clms Page number 9>

 
 EMI9.1
 for position four of the combiner, 1 <circuit is ready to receive the pulses corresponding to the digits of the units of the requested number. These pulses are transmitted to SM, or SIVJ2 as the case may be, as a result of the maintained excitation of the Ir and Fr relays.



  When these pulses are received and A2 is neutralized, the combiner moves from its four to positions. ten. The line is tried, and the reoh-rche of the P.B.X. can take place di! the manner already described in our patent 3I8.'27, the circuit providing for the possibility of searching on a group of four lines 1, B.X. It should be noted that the relay Jr is provided for 8V, C a non-inductive shunt so that
 EMI9.2
 the relay does not operate for ringing current when the telephone set receiver is resting on the switch hook.
 EMI9.3
 



  So the resistance which is placed in series with .L, j relay Jr for a search of the P.B.X, is of a different value.
 EMI9.4
 



  If the. line is free, Vr is neutralized and Jr gets excited:
 EMI9.5
 earth, Jr, left outer armature of Vr, contact 4 (sapériv or right and left), relay 'Pr, and battery. M relay Br is energized through a circuit passing through the armature at work of Jr and the upper left contact ¯A. The 86 ut combina through its 10 1/2 verse position. its' eleven position or ring position.



  For this a circuit .sot provided for the common relay Rsr da is shown in figure 2 :. earth, right winding of Fr, contact 0 (lower left), Ksr relay,. 1 battery. The complainer Jr xwsy4; neutralized while the relay d6, starts, ge oper .. The ringing co; #am: is IHlvo; yed through .the .relay itr and 1.spring * at the called substation, then.returns through the spring G aux i'flrOuloèl] J1l ;; l1 '!; Z
 EMI9.6
 of Er, Jr and its non-inductive shunt.
 EMI9.7
 



  By connecting the relay cta switched on. from the BO Il to the ringing current through a ###. ##,. #, a si; nal of a this. tain ton: PtU Stre obtained through the resistance irdividu, ll in & e if the current ..t! . da sor.ù1r'iè na must 'f <' TO <lr a t, V C :. '(....., 0 Q' .J .. \ j c .; Ú J.tLt. "T..Cv # ll natr on shared links s. T 'Figure!., 6 showed, circuit for all li ,. ex- ap e. the last of a [jroLl: pe PBX The adaitionnal relay OOl: C dor "

 <Desc / Clms Page number 10>

 
 EMI10.1
 s sort: expected f;:; 'Llli', 1 "nt in some special cases. This figure is only intended to complete the description.
 EMI10.2
 



  The current ringing tone can be produced by the arrangement shown in fig.2. u,; j nd; .1; ci on 1 - ..! wish, a small p-jut call generator to be instructed,.: - t 17s Jr and Br relays are constructed so that they can be v-ixci connected in the circuit of this generator.



  If the resistance of the subscriber lines does not exceed 500 ohms, the relay nr J'u'L Ctro omitted, ç, t 13 relay Jar controls the calling circuit. On e1 ..; 1 longer, lines, the relay Jr cannot operate, but 1-'cr pizza then bag, .xr operation until the lines offering resistances of the order of 1000 ohms . The Rr relay
 EMI10.3
 should be used when shared lines are in use.
When the called subscriber answers, the handset moves on; positions eleven to fifteen. The relay Pr is energized for the dou position
 EMI10.4
 ze through 10 circuit of the called line.



   When local calls are to be counted, the! Circuits shown in dotted leagues should be added, while connections marked with a cross (x) should be removed.
 EMI10.5
 Let the ca.s where eJ: 'ré1nG, -m':. Nts, for counting calls; occur. When the combiner goes from its 11 1/2 to 13 positions, a
 EMI10.6
 circuit is closed for the relay Met battery, contact D, upper armature to work of the x, relay Wall, and earth. The Mr relay, when energized, connects the additional counting battery to the cri terminal and to the circuit of the relay Tr which is kept energized, the other end of the winding of this relay Tr being connected to the earth. by one
 EMI10.7
 other reinforcement of 1,; '1'.

   In this way, if the relay Tr momentarily abandons its armature for any reason, it cannot break its circuit, and is immediately energized again. Contacts!
 EMI10.8
 of rtlJ.t, ls ... r:.: have adjusted and the resistance in series with the relay Tr is such that no reversal of current occurs in! the circuit of this relay Tr, neither during operation, nor during:
 EMI10.9
 Restore it from Mr. Le comptuur MS of the subscriber's line drill 'L lOî11 to 4.r.vx'N 1. following circuit: battery, MS counter, terminal and "ü81ai c, MX- armature, Gold relay , and additional counting battery.

 <Desc / Clms Page number 11>

 
 EMI11.1
 



  The Relais Or is a sensitive râlais. It breaks these armatures to the circuits of the Gold starting relays, so that the function of the conpts.4jx Ull.,> 1.t: t> appl: -and, received, 1 , s dear line chsurs are stopped saw the oc test can take place. No interference with the meter circuit can therefore take place, which would be the case if another Tr éx-Oxcitated Test Relay shorted it. resistance on which it operates. read. Relaie Or is planned for the two units of one, installation of 70 lines. Oc.relais also works when the count has 1i..u. of a 1i ...; 11 ;;: connection through 1 TALC conductor or of an interurban connection
 EMI11.2
 a main central office.
 EMI11.3
 



  If the connection is made at the air end of a connecting line, that is to say of a 12rc; bringing together sweet similar offices, such as two rural offices, the rnSwô circuit is used for the operation of a me.i, U4nal relay on this link line to the
 EMI11.4
 instead of the meter, this relay providing a 'lice * circuit to determine the
 EMI11.5
 time elapsed since the, corn: z;. after the conversation and the operation of the counter at the elf end of departure. A & description
 EMI11.6
 of this arrangement is given below.
 EMI11.7
 



  If the first local calls should not be counted while the calls using a connection line ûoiV.l'1 / .L '; tï'd, the account'Ltr bare must not be connected to the terminal ".çj1 trlais must txw co .. ;; é between terminal "d" and earth. The counting circuit of the cord is then used to transfer the desired current to the end úù the departure of the link line. We must J10t, "l that in this case a doubla voltage metering battery is needed for 8. () tio;, n: e: c the comp-
 EMI11.8
 tor which is connected to earth.



  After the calling subscriber hangs up his receiver, the
 EMI11.9
 Relay Ir is neutralized and relay Dr returns to its normal position, - Relay Tr, deactivated from the terminal., is neutralized by oouct circulating the Sr relay. This one abandons its reinforcements and in or-
 EMI11.10
 By turning on its blocking circuit it causes the relay to re-establish it
 EMI11.11
 Kr. The combiramr moves to its sixteen position for which 1 oommu-

 <Desc / Clms Page number 12>

 
 EMI12.1
 tataur SM 2 st brought back. at rest, if .. this switch has been used. The combiner - then passed has its seventeen position for which the oom- mutator SM is brought back to. normal position.

   The reset circuits are similar to those described in our patent 318,727 B.C. except that the combiner positions have been chosen so that counting can take place.
 EMI12.2
 



  If L after the called subscriber hangs up his receiver the correct a.¯5pcla.nt m does not break the connection, the relay Er can be activated through the common arrangement in time, with the aim of to release the calling line * t In cord circuit of the. way already indi-! quée. The Er relay circuit is also closed for the qu.in position! ze or. conversation position, through the resting frame of hx and the bare frame worked Mr.

   It is obvious that the Er relay can get excited at the. end of any call if the switch goes time comes to close its circuit at that time, but the essential part of that. ara.tïo ::. nt: st that this relay must not be kept energized for a time interval of more than 30 seconds for example
If the requested line is found busy, the Vr relay is;
 EMI12.3
 kept energized for position ten of the corabineur, and the Jr relay cannot operate. The combiner 11: could therefore leave this position. A circuit, when closed through contact B (lower left) and an individual resistor.

   This circuit, which causes the establishment of an auditory signal, is arranged so that the Ur lead of the cord is intermittently connected to contact B, and
 EMI12.4
 that when it is excited it transmits the said signal to the line. It should be noted that if a busy signal of a frequency different from that of the dial disc maneuver signal is required, an individual relay, instead of the common resistor, has been provided; cerelais connecting to the line a circuit for separate auditory signal.



   When the calling subscriber hangs up his receiver, repeat Ir and Dr are neutralized, and if relays Tr, Sr, and Rr come back
 EMI12.5
 at rest, the suit goes from its ten to sixteen positions. The circuit of the counter, originally described, is then opened by the relay Nr.

 <Desc / Clms Page number 13>

 
 EMI13.1
 For demonstration purposes, line 1P 70 is assumed to be non-existent or disconnected. If a call is received on the terminals of this line, a common circuit, not shown in the drawing, is
 EMI13.2
 closed, which provides the calling subscriber with a specific signal (approximately supt "clicks" per second).



   Figures 2 and 4 show the common circuitry for producing the auditory busy, dialing disc operation, and ringing signals. These circuits also provide the means to liberate a line on which there is. a permanent closed circuit, or a line that remains connected after the called subscriber hangs up his receiver. The auditory sigml for the maneuver
 EMI13.3
 of the disc is produced in the usual way in small can traux offices.

   To produce the auditory busy signal, common relays are provided which establish the same circuit as that used for the previous signal, but this establishment only takes place at
 EMI13.4
 intervals such that the operation of the vibration relays is reduced to a minimum. It should be noted that: in 1k case where it is desired that the auditory signal of occupancy differ from the signal of maneuver in the sense that from the point of view of the frequency, the circuit envisaged must be
 EMI13.5
 established dfféLlIr.1nt, while a hearing rattle is provided for the cord circuit. As regards ringing current, the ordinary arrangement is provided, and it is assumed that this is sufficient for small installations of this kind.
 EMI13.6
 



  An alarm signal could be transferred to a remote main Cd lrtral office through one of the office's trunk lines Since such a line is used for two different purposes and can be busy at the time the alarm signal is set. , an arrangement is provided to sever an existing connection and cause a call to the office through the line, thus giving a gone signal.
 EMI13.7
 aulier. This way it is easy to sever a connection to the rural office. In the main central office the signal persists until the existing connection has been severed. Arrangement 1: ut vary depending on whether the central office has a manual switcnboarû or an automatic installation.

   The circuit shown in lines

 <Desc / Clms Page number 14>

   dotted line is intended for use with an auto viatic central office. In this case the connections marked with a cross must be broken.



   In order to ensure that an existing connection is first disconnected, the arrangement of the alarm circuit is made such that the conductor "b" of the trunk line is opened and closed at certain buffer intervals, while that on the "a" conductor, the potential varies at the installations, except at the first interruption.



   By this arrangement, if the connection, axistant prevents the rural installation, the. connection broken, and when conductor "a" is grounded, one is created at the office. When a recorder is used, the interrupts to conductor "b" remain; without influencing, since the step by step relay of the recorder is kept energized through conductor "a". A permanent signal is therefore produced at the office recorder.

   If the existing connection comes from the central office, the break of conductor "b" becomes effective after the calling party has been swept at rest, after which the call is made and a permanent signal is produced at anragistraur. free.



   If the central office is of the manual type, the circuit is modified to provide a permanent earth on conductor "a" and a slowly flickering signal on conductor "b", which may be added to a characteristic auditory signal. sending one! some shadow of clicks through the laundry, as noted above. The alarm circuit is closed whenever a fuse blows.

   The same circuit is also closed if the bell current source fails, and in this case a set of slow-acting relays is provided so that if the bell circuit is closed, one relay is permanently bypassed. on the bell current source, is neutralized, and an alarm signal is generated at the central office. The slow-acting rails are provided in order to disconnect the alarm signal when the bell circuit is in action,

   so that the vibrator relays can be used only when there is a real need to transmit this ringing current.

 <Desc / Clms Page number 15>

 



   In the arrangement used to release a line on which a permanent closed circuit has been created, a special relay is provided to the local cord circuit shown in fig.l. Common circuits include a periodically moving switch for counting time, a special line finder called a closed circuit line finder or reset switch shown in figs. 1,4 or 5, and one individual relay per substation. When the local collector circuit is connected to a line, or when a calling subscriber does not timely break his connection, the relay in the mentioned cord circuit is energized when the time switch is in one of its positions. rest.

   This relay then takes place. blocks through a common starting relay, and the time switch, under the action of a vibrating armature relay, advances its brushes step by step, at a rate of one step every six seconds. A terminal is thus reached on which the corresponding relays are energized if any of the aforementioned relays in a bead circuit remain energized for a period of at least 30 seconds. By the action of these common relays, the circuit CI: \ start of switches for calls / ICI 'or calls for connection lines to offices, similar, is disconnected so that only the finder for closed circuit line permanent can turn.

   A characteristic potential is placed on the corresponding terminal of the line comprising the closed circuit, so that when the searcher reaches this terminal, it stops and causes the operation in a local circuit of the additional relay., This last relay turns on. then hangs at the line. The / local cord circuit is released as well as the circuit searching for the permanently closed circuit line.



     A detailed description is now given. One must observe that when it is spoken of a handset contact, it is about the combiner of figure 1, because no other apparatus seems to be considered.



   Auditory signal for the operation of the numbering disc. For position two of the cord circuit combiner shown in fig. 1, the Ur relay is energized in series with the Tsr relay for production

 <Desc / Clms Page number 16>

 an auditory signal to start the disc, and for the production of a signal.! auditory occupation. This Tsr relay closes the auditory signal circuits. Shown in the larger dotted line rectangle at the top right of the drawing.



   Auditory busy signal. When the * local cord circuit shown in fig.l reaches occupy position ten, one circuit is closed across earth, contact B, an individual resistor, has a common relay Ar (fig.2). The latter is shunted by a non-inductive resistance through its armature at rest, so that it operates slowly. When the Ar relay energizes, it closes the Br relay circuit and breaks its shunt so that Ar becomes slow recovery. The râlais Br being also shunted through; towards its armature at rest by a non-inductive resistance, .function slowly.

   When the relay Br has attracted its armature, this shunt is broken and the relay becomes reset. A circuit is also closed for the Gold relay which in turn closes the Orle relay circuit An individual contact for each local cord circuit is provided on these two relays through which the relay circuit
Ur (fig.l) is closed through contact B. The Tsr relay is therefore energized and the signal is sent to the calling line.



   By one of its reinforcements, the relay Cr1 short-circuits the relay Ar which is neutralized slowly, after which Br is neutralized in turn slowly. The relays Cr, Cr1, Ur, and Tsr return to idle thus providing an auditory signal followed by silence. If any other bead circuit is in position two, and the corresponding relay Ur is connected through the rail Tsr, the auditory signal is produced continuously, but is such only for the bead cooked air whose combiner is in the maneuvering position of the numbering disc. As a result, the cord circuit, which is in an occupied position, receives an interrupted auditory signal.



   If the expected number of bead circuits is small, the Cr1 relay can be removed. its left armature then being controlled by relay Cr as indicated. The duplicate equipment indicated inEBtr is placed under the control of the O.T.K.

 <Desc / Clms Page number 17>

 



   Auditory signal corresponding to an unrealizable requested number. If a call concerns a line which cannot be obtained, a particular signal, of approximately seven clicks per second, is sent to the calling station as a result of the energization of the common relays.
Hr and Ir. In the local cord circuit shown, it was assumed, by way of example, that line N 70 had been taken out of service.



   The circuit is such as to allow operation of the cord ringing relay Rr through conductor "b" and a resistor to the battery. The cord is then placed in the conversation position and the winding of the relay Pr, terminating on both sides at the battery, the relay remains deactivated. The relay Hr is connected through a high resistance to the conductor "a", this rail being energized through the second winding of Pr. The circuit has a resistance such that Pr cannot be energized. The sensory relay Hr forms a circuit for Ir, which by being excited short-circuits Hr.

   These relays Hr and Ir, thus provide an auditory signal of a low tone, and the variation in the potential of the conductor "a" provides a distinct signal to the calling subscriber.



   Ringing circuit. The common ringing device is shown in the dotted rectangle placed at the lower right of the. fig. 2. For the ringing position of the local cord circuit, the Rsr bell start relay is connected through a large individual resistor to contact G of the cord circuit, then from there to earth through the circuits in parallel, one of which passes through one of the windings of relay Pr and the other through a non-inductive resistor. The relay Rsr energizes closing a circuit for the relay Dr. This in turn closes the circuit of the vibrator relay Rir, which closes and opens the circuit of its nerie at determined time intervals.

   A description of such a relay can be found in our patent 316,811 of March 12.
1924 The bell circuit, comprising vibrator relays and a transformer, is of the ordinary type and need not be described here. Rir relay keeps Dr energized during intervals

 <Desc / Clms Page number 18>

 ringing, so that when a new call is established, the ringing current is sent immediately to the line. As in the case of the auditory signal circuit, double equipment is provided for enEEr, EFr, EGr. Switching from one device to another is done using the ORK key.



   Fixed-time alarm signal. If the ringing current gourée fails, an alarm signal is sent to the main central office, which energizes the Xr relay: earth, Xr relay, armatures at rest of Lr and at work of Kr and Dr. Relay Jr is bypassed permanently to the source of the current ringing tone. It is assumed that this relay always remains energized during the sending of the ringing current, keeping the winding of the relay Kr short-circuited to its make contact. If Jr does not keep his armature attracted, the slow-acting relay Kr gets energized through Dr.

   Since it is necessary to keep the buzzer relays of the bell circuit disconnected when it is not necessary to send ringing current, it is necessary to prevent the alarm at the central office at the moment when the ringing current is sent and before the ringing current is sent. excitation of Jr. For this purpose the relay Kr remains short-circuited through a contact of Rir during the silence interval, while during the ringing interval the relay, Jr is, in order to operate quickly, followed. by the slow acting rail Kr. The slow acting relay Lr is then neutralized. This operation was repeated at the beginning of each ringing interval.



   When a fuse blows, the Xr relay is immediately energized following the closing of the FA contact. The signal to the main central office is transmitted through one of the existing inter-bus lines. It is assumed that between the main central office and the rural facility, the trunk lines are used for automatic or non - automatic service, and that no monitoring is provided for the rural facility. If the main central office is of the manual type, the drive is operated at one of the operator positions.

     As the alarm signal may be sent over a trunk line at the time that line is in use, part of the,

 <Desc / Clms Page number 19>

 connection in the rural office Is made by connecting the terminal "c" of this line to the earth and disconnecting the conductors "b'J
The existing connection in the office will first be remote, and the storage for transferring the alarm signal may vary depending on the arrangement provided at the main central office.



   The line of the main central office is indicated on the left of FIG. 2 by the conductors E. The conductors E4, E5, E6, are respectively the conductors "a", "b", "c". The corresponding wires "a", "b", "c", of the local line are indicated at L1, L2, L3.



   In the case of a manual remote office, the cabling is provided as shown in solid lines in the drawing. Through one of the contacts of the Xr relay, the common step-by-step switch is turned on. Through an Air time relay, the slow movement of the switch is realized. This is best understood from the following.



   The trunk "b" conductor of the trunk line going to the main central office (IL) is connected through the left outer frame of Xr, to a set of stepper switch terminals which, at equal time intervals, closes and open the line, so that slow processing is created at the central office, (by means of the monitoring relay on the calling side or the called side). The conductor "a" of the interurban line (E4)

   stay connected to the. earth through an Rb relay. The auditory signal, described previously, and which corresponds to an impossible number, can also be sent to the "a" conductor. After the existing connection in the central office is broken, this signal acts by itself on the line relay. Earth applied to conductor "c" to. through the right outer armature of the Xr relay, restores the local device, if necessary.



   If the main central office is fully automatic the alarm signal circuit is established as well and shown in the dotted line drawing. 'There are therefore in addition the additional relays Wr and Xr1. Oomexions with criox (x) must be broken. Additional relays are necessary to achieve all possible conditions on these linens.

   If at the time

 <Desc / Clms Page number 20>

 where the alarm signal is created, the long distance line is busy, it suffices to cut off the connection to the central office by temporarily breaking the linga through which the call arrives at the office. If the call comes from the central office, this break can be maintained and must be repeated until the calling subscriber has disconnected his set. A call is then created and remains on the line until an alarm signal is activated, which attracts the attention of the supervisor.

   However, it is necessary that this call is not interrupted each time the line is broken. The arrangement is therefore such that the relay Xr causes the time switch to be started while the relay Wr opens or closes, at certain time intervals, the conductor "b" depending on the position of said switch.

   In time, the "a" conductor is disconnected from earth and connected to the battery through the right armature of Wr and the left armature of Xr. This last connection can only be established after a break in the conductor "a" has taken place) this is done by the relay Xr1, which, when activated, blocks through a circuit passing through the right frame at work of Xr.

   occurs If the common alarm signal is at a time when the internal, city line is in use by a received call. at the central office, the first relay Wr is energized, and the connection to the office is broken.



  When the common switch moves its brushes one step, relay XR1 energizes before relay Wr is neutralized. The "a" conductor is connected to earth through the rest armature of Wr, and the call is broken at the central office. When, the step-by-step relay is chosen in the recorder or the associated lead with the. Connected to the central office, this relay first remains energized through conductor "b" to earth.

   The next Wr relay energizes, conductor "b" is open, but the second winding of the central office stepping relay sa maintains through conductor "a" and the battery. After a certain time interval, the permanent signa.1 is produced at the central office.



   If is produced from the central office itself, it is

 <Desc / Clms Page number 21>

 important that conductor "b" is broken after the calling subscriber has disconnected. The switch in time is then re-established and the call is initiated at the central office.



   Permanent closed circuit. When the combiner of a local bead circuit reaches position two, the Er relay of that bead circuit energizes if the time switch is in one of / its off positions. The relay Er is then blocked through a circuit
 EMI21.1
 comprising the Ur relay of fig. 2, and these dî5ax relays remaining them- selves as long as the combination of the cord circuit occupies its position two.

   Ur flour, by its left armature, a circuit
 EMI21.2
 for a relay on time, while who? by its armature di:;, right it makes me a circuit for the electromagnet step by step SM. This circuit pressed
 EMI21.3
 te a derivative path y,.;: Na..a by a slow operating relay Vr the purpose of which is to keep the Sirli circuit closed only weighing a sufficient time for the excitation of this 6la'1; the u imant., but not while the time relay keeps the circuit closed. The so-called position prevents overheating of the electromagnet. From Ctj "t.'t0 manier SM makes his brushes take a step every sixth of the week.



  If the relay Er of the cord circuit of the iig.l, is kept energized beyond a certain limit, i.e. thirty seconds, the e
 EMI21.4
 The magnetizing step by step reaches a position for which a circuit is formed from its brush "a" to. through the outer frame *; left to work of Er and the windings of relays Zr and Yr, which are common to a group of c ord on circuits. The step switch
 EMI21.5
 stay in this position for about six seconds for a normal f'ollctionr; ', ;;; Üli ..; l1t.

   The r ..L.8, is Zr opens at its rest contacts 1 ,,,; 8 common circuits for unappd "0" and the sa, y: ls for lion s ci connection V.:.;l'S des offices s1r.b18blt; s "in this group of cord circuits, the earth for uas circuits being provided through conductors such as ZO. The Zr relay by closing its working contacts, establishes a circuit.
 EMI21.6
 cooked for 1 \ ;; , co) Disconnection jrt1Uah shown in figures 4 or 5. The Yr relay connected the battery to terminal "d" of the circuit.
 EMI21.7
 lead through the Er relay contacts (fig.l).

   In an installation of as many * .i; nw-s, tsll ,, qu ... c.ll. described here, a 'group

 <Desc / Clms Page number 22>

 
 EMI22.1
 of bead circuits, and consequently two ilOL?, Jë: S similar circuits of cJ.éJJ1 ['rr ["i ::, are provided. The circuit for the electromagnet of CierI'] 81T8 {'iL .. CO: 1JLltf "t:'! 1..1.r Cl disconnection shown in fig.4 is closed through a contract of the ru le '18 test Ar (fig.4), and the armature at 1: l "8VB.i1 of rrlais Zr fig.2. The winding of relay Ar (fig.4) is
 EMI22.2
 connected to earth through a contact, working Zr. This relay
 EMI22.3
 Ar is such that n y c ';: = not on a terminal "b" on which a r.iîp:' 1 "Cn or u; î a.; Y: 'i for connecting lines is created , that is to say when 1.- circuit ,, st fôrrné through the winding of a relay such CLl :, Ci'UJ'1 ClrC.:1 '' :.

   C cord, while 1 Ar relay is energized when the i-coil and connected to the battery through the armature to the traj goes, there is a small profective resistor.
 EMI22.4
 



  A * similar series of operations is performed when the com
 EMI22.5
 mute, tt,;. '; 1.a "in fig.4 is replaced by the one shown in fig.5. This last conilllutt:' 1téL # is better described in vaG connection the circuit for lig # s, binding of the Iig.3., For installations not including.of canvases 13.; 11;: 5, 1 ;, 'Cp; ,, Ll!;. a, d¯: ür from the figure 4' t'st sufficient.



  L s conduct; "jl..1, rS SS are individual to the subscriber line and 'are associated with' Y. ': C 1. line addition relay Llr as it is., Shown, and ev ; '; c us bor # s .ê:., 1l, .. Q.,. Q., individual11lws à la, lined, sur le jc ^., Jïiîi22L1 d ... CM?:, Y.Ciit = L11'S . conductive cases are indicated in the section
 EMI22.6
 upper right figure
 EMI22.7
 sqJerv: u.r .; (ll'O1: 'll'e igUl t :: LE1 tôrrf. connected to the arnaturo da right of. Zr (fig.2) provo that the excitation of the electromagnet step by step SM of the switch de- connector This COmr; JLtt8.t1..1r searches up to the terminal marked "d".



  The relay Ar is then energized through the circuit originally tre
 EMI22.8
 ce: Yr d le. fig. 2, Er contact (fig. l), terminal of the
 EMI22.9
 cord, born. "d" of the disconnector switch, Ar relay, Zr geucha armature (fig.2), and earth. Getting excited, Ar plans a circuit through his é'.l. "1J1l? TuX ': i} at work and the researcher's broom" c ",?. End ¯:,: ciU ;: ; r 1. individual Llr relay to the line. This relay then blocks, through its al "., 1aturs at work, to the driver flb" of the li, from tell, so q: "lè 1 & COlICILiCtw Ur" â .1 'ibst excited through a second armature at work of Llr. To the ground .. L. 1' .-

 <Desc / Clms Page number 23>

 lais Llr is now excited as long as a closed circuit is created on the. line.

   Through another frame at the work of the.
 EMI23.1
 Lir, the "c" conductor is connected directly to earth. C ..; restores the cut-off relay and maintains the line relay
 EMI23.2
 disconnected. The earth on the oc "conductor causes the well-known his-nihiy to reestablish some local cord circuits on this line.
 EMI23.3
 



  The cord circuit,; st li:; ndJ .... L "l'ê: 1 and the c; u ff, lJ 11'.ia. '. X' cl moves to its doox position. 'The device to n: .. ::,; s is therefore s anal 1 <";. 1 '-; - born at rest, the apparatus coirimun, -; 8't iestablished at If. normal, and 1s CO..m1iJ. re-establishment tor comes free in .J,; I: t last position.



  Through another armature at the work of x; lais Zlr, uns t <t ::; '<1 is connected to (7'ucS.i.Cli1'alltr test terminal tôix¯ than r1'r., Which is 21 if kept busy. Through another working contact, a: 1? L local; Jx. '.' Ll'C. Trtî connected, if we 1:,. Desire, l,) o; .r, # eil1tJ1h " thus C4tw. to indicate immediate1. '. mf,;: 1.t,; La linu f:; ". which Lir ,, - st. blocked.



  CLs nc1 1 Ur relay of the 2: C1 '";'. Gr.1c; n CO; f1 ,,: one of 1 figl1.l't. 2, gets excited, the éï:, c ûx 0 "d.,. I? 'u ^ .. nt SM returns, to tl'pv",: rs its contact d &1'.i;: - pos, to its normal position.



   The same arrangement is put into action to effect a re
 EMI23.4
 time establishment of the devices under the control of the called subscriber. In the present invention, the re-establishment of the con neotor device takes place directly under the control of the. calling party,
 EMI23.5
 but also under * 1 co.ntrôl, of the pertiô called with the forecast of a time limit ¯ before the restoration takes place. This fact is important since the seizure of the devices by a calling subscriber is really prevented.

   For example, if the called subscriber
 EMI23.6
 removes its receiver for a * j ar) 8t: J1C \ 1 from the calling subscriber, the control cir on cooks / remains in the r. position q¯Li, zÍ; j da,:; () :. 1bI1 \; \ r1 and the relay "and is still txoited, pewjwttajit the reestablishment of Fr, the circuit being the same as previous: il. ^. i ' i'l ;. The 4'UY: T: ïal: attsar à (,, \ :. 1J: 11) 8 functions, 1 and if the a b Or. '1e'. "r '" paS SO1't û, 11 b01,1t d '; 1i1: ili.sï'- the subscriber aelr î.tj does not pick up his receiver at the end of an interval of time required, or not> ci ::; l., r :;: ¯ ;;, e6cond <; ls "a forced reestablishment takes place and the line is released. The resulting break

 <Desc / Clms Page number 24>

 
 EMI24.1
 of circuit f: rraé, rla c line An in service state.



  Fig.3 shows a line of connection, that is to say a line of junction -r binder d. .: ax 'rural offices of the automatic type and provided with local connection circuits of the type shown in fig. l. If a c = ganre line becomes defective for any reason,
 EMI24.2
 Very important losses can result since in the type of, 4 bjjrau considered no monitoring normally takes place.



    Marna if an immediate alarm signal is given to the central office, a; a certain time elapses before the fault which axistô on the line
 EMI24.3
 be repaired, and during this time considerable damage has resulted to the service. By the arrangement shown in f ig. 3 a line of li-
 EMI24.4
 a.is fault is disconnected at both ends at the rural offices, where moreover the devices corresponding to estta ligna return to the normal position, provided that the disturbance is sufficient to act on a râlais da ligna pt cause an appl.



  A particular advantage of this arrangement is;
 EMI24.5
 the fact that the device used to restore the subscriber lines to normal is also used to disconnect the link lines. 'So if a disturbance occurs when the ligna is not
 EMI24.6
 occupied, an a.pp1 is created at one or both ends of the lig-j ne. It follows that a local cord circuit will connect from it-; mema, after a determined time interval the disconnection apparatus shown in fig.5a will come into action to restore the corresponding apparatus to normal and disconnect the connecting line at both ends.

   The arr2n; tilt, st that the disconnection at one end immediately created a call at the other end, so that the disconnection apparatus at this last end entered an action of the ordinary way at the end of 'some time. When the disturbing * on the line ceases, calla-ci is automatically made free.



   Another important fact of the arrangement described is the provision of means by which the forced disconnection of a binding fabric is carried out, when this line. is kept busy for a subscriber on whose line a fault has occurred, or

 <Desc / Clms Page number 25>

 when a subscriber has used this pheasant line but has not hung up his receiver on the switch hook. In this case, a series of operations similar to those described above take place.

   Thus, if the cord circuit, local at the arrival end of the connection line, after having been maintained for a determined time, causes the disconnection of this line while changing the direction of the current in this line in order to release the subscriber line and create a permanent call at the originating end of the trunk line.



   If the fault reaches this one, then obviously its originating end is disconnected. If the link line is in order, the busy condition at the terminating end, and consequently the call having to the starting end, are canceled. The subscriber line / - undergone the storage line is obviously disconnected in the manner previously described.



   The arrangement which achieves these goals is such that the line relay at one end of the line is connected between conductor "b" and the battery, while the line relay at the other end is connected. between conductor "a" and earth.



   The operation of the relays used to disconnect the line is such that they apply, in cooperation with the disconnect switch, a potential either on the "a" conductor or on the "b" conductor. There is sufficient potential to actuate the line relay at the far end. While a local call is connected to the incoming end of the line, the closed circuit is completed at the outgoing end through a counter relay and a differential winding relay. The reversal of the current in this circuit is used to release the differential relay and thus to effect the forced recovery of the associated device. A temporary increase in this current, on the other hand, is used to actuate? counter relay at the start end.



   A detailed description of the circuits shown in fig.



  3 is now given.



   The calling subscriber who wishes to be connected to a sound link leading to a particular office, marks on his disk number-

 <Desc / Clms Page number 26>

 tor a definite number. The lowest selector switch, shown to the right of fig.l, moves its brushes to a certain set of terminals, for example the terminals marked 0. The battery is then connected to the "d" terminal of the finder. lines through the following circuit: battery, left winding of Pr, contact H, armatures of Nr and Kr, brushes f2 and f1, and towards the brush d of the line finder. In addition, an earth is placed on the OFS conductor as follows: earth, right winding of Pr, contact G, upper armatures of Nr and Kr, brushes e2 and e1, left armature of Pr and OFS conductor.

   Terminal "d" is marked as described in the case of calls to an operator at the central office, or to another rural automatic installation through a link line. However, in each case an earth is connected to a different conductor, in order to set in motion either the position finder switches and the searcher switches of the central office, or, in this case, the line finder switch. fig. 3.



   It is assumed that the terminal "d" of the FS1 finder is at the desired potential, and that the earth is connected to the conductor of the connecting line indicated by BO fig.3. This BC conductor corresponds to the OFS conductor in figure 1. The Er relay (fig.3) is energized. If the office is large enough that two groups of core circuits are needed, one of these groups can be linked to conductor BC and to relays Er and Gr, while the second group is linked to conductor. BC1 and to relay Er1 and Gr1. Each link line circuit is then provided with two seeker switches FS1 and FS2 as shown in the drawing. The Er and Gr relays are common to all link line circuits of a particular group of bead circuits.

   Obviously, the number of grm paces of cord circuits and the number of groups of corresponding equipment may be greater than that mentioned, if necessary.



   By its excitation, the Er relay closes the following circuit: earth, ZC armature (which is controlled by the Zr relay in fig. 2), left armature of Cor and Er, right armature of Gr1, re-

 <Desc / Clms Page number 27>

 Gr lais, battery and land. Relay Gr energizes and closes a circuit for relay Cr, which sets in motion the seekers of free link lines in order to find the calling line.



   The excitation of Er also results in connecting the earth of the ZC armature to the AC conductor. This earth can be used for any monitoring purpose, for example to indicate that researchers are in action. The Er1 and Gr relays operate exactly the same as Er and Or. In addition to its right outer armature, the Gr1 relay closes a circuit for the Mr relay through the resting armature of Cor. The Mr relay closes a circuit for the Kr relay which disconnects the circuits from the terminals of the first row finder for the relays at the terminals of the second row finder. The Mr relay also disconnects the Tr relay from the first line finder and the relay from the second line finder. The Gold relay is designed to disconnect all the starting circuits of a group of reason lines.

   Thus if all the connecting lines of a group are occupied, the circuit leading to the ZO armature is broken on contact with Cor, and the connection of the battery with the AC conductor causes the excitation of Or which places a shunt through the Er and Er1 relays, preventing the establishment of other calls.



   It is assumed in the first place that the calling subscriber is connected to a cordun circuit and that he has marked on the disc the number of the connection line between similar offices. It is also assumed that the earth is connected to the conductor BC by this cord circuit in order to cause the excitation of the Gold relay. This closes the following circuit to cause the operation of the electromagnet SM: battery , electromagnet of SM, left armature of Mr, automatic armatures of SM and SM1, left armatures of Cr and Dr, left armature at rest of Tr, and earth. The step by step electromagnet operates and is neutralized to advance the brushes of the searcher Fs1 to the terminals of the calling line.

   Closed circuit: battery, terminal "d", right armature of MR, right winding of Tr, right armature of Dr, and Cr, armature of Lr, and earth. The relay Tr s'

 <Desc / Clms Page number 28>

 excites and breaks the circuit of the electromagnet. In addition, the relay Tr is blocked through the circuit of terminal "d". Finally, the relay Tr breaks the shunt of the relay Fr which is excited in series with the step by step electromagnet. However, given the high resistance of this relay Fr, the electromagnet SM does not work. - Firm circuit: earth, Fr armature, Xr right winding, Br relay, and battery. The Br and Xr relays are energized. The relay Br connects to the calling line the windings of Ir which is thus excited through the circuit of the calling subscriber.

   The relay Ir closes, by its right armature, the circuit of the relay Fr which is kept closed. By its frame. lower, the Br relay connects the earth to the finder's "c" terminal.



  It follows that the local cord circuit is released and that the subscriber line is placed in a busy condition. By its upper frame, the relay Br closes a circuit for the right winding of Cor, while by its other upper circuits Br extends the conversation circuit to the link line through! the capacitors shown. By being excited, the relay Cor moves the earth away from the relay Gr which is neutralized and breaks the circuit of Cr. The Cor relay, by its outer right armature, provides a blocking circuit for Mr when necessary, at the time of the rupture of the primitive blocking circuit to its inner right armature.



  The earth connected to the inner right armature of Cor also provides an excitation circuit for Dr. This one closes a circuit to its mature inner left ar through the earth, the upper armature of Br, to the terminal "c "incoming searcher switches cooperating with the link line, which makes this line busy.



   When the relay Ir is energized, a circuit is closed to connect the battery through the left armatures of Ar: and Ir, and the upper and inner armature of Br to the A conductor or upper conductor of the link line. . This results in the excitement of Lr1 at the remote office. As the arrangement of this desk is similar to that of the desk envisaged, the left part of fig. 3 may be considered for ease of description. By its Lr1 excitation closes the following circuit: battery, right winding of

 <Desc / Clms Page number 29>

 
Cor1, right armature of Lr1, and terminal c of the local line finder Br. By its left armature, Lr connects the earth to the starting conductor SW1 of these searchers.

   Those associated with the trunk circuits of a particular group are then activated and search for the calling trunk line. In this case this. trunk line can be considered as an automatic calling subscriber line. When a seeker has reached the line under consideration, the Cor relay is energized, which causes Dr1 to be energized. The latter by its inner left armature breaks the circuit of the line relay Lr1, while by its inner right armature it closes a new circuit for the Cor relay, which therefore remains exited through the conductor of the circuit. cord.

   This cord circuit acts as was originally described in conjunction with Fig. 1, and when the circuits are prepared, a subscriber receives the aural signal for operation of his dialer disc, through the link line. This subscriber can then mark the number of the line called at the remote office.



   Each opening of the subscriber's circuit, as a result of the movement of the dialing disk, causes the neutralization of Ir in fig.3. The relay Ir, by its right armature, opens the circuit of Fr, but since this one is slow recovery, no change in the circuits takes place. By its left armature, Ir opens the fundamental circuit extending through the cord circuit. It follows that the Ar and Xr relays are neutralized. The new closing of the left contact of Ir brings about an immediate connection of the battery connected to the left armature of Ar, to the conductor, µ¯ of the line.

   This results in a new operation of the step-by-step relay of the ci-.1. fired cord (corresponding to relay Ir in fig.l), since one of the windings of this relay is connected between earth and conductor a. This arrangement ensures an exact reproduction of the pulses. The cord circuit causes the operation of the connector switches, and connects the line of the called subscriber to the link line. Conversation and recovery take place in the ordinary way.

 <Desc / Clms Page number 30>

 



   Counting. When only one operation of the subscriber's meter is required, the circuits shown in dotted lines are provided, while connections with a small cross (x) must be broken. In this way the Yr, Yr1 and Zr relays are introduced into the connections. When the called subscriber answers, the cord circuit connected, in this case, with the panel Br of fig. 3 applies the booster battery to the conductor c at the middle of the Gold relay shown in fig.l. This battery caused the Yrl relay to operate, and it follows that it is connected to the contact of
Yr1 through the conductor has the line. Considering the circuits taken in connection with those of FIG. 1, it can be seen that there follows an increase in current on the line, which causes the excitation of Zr.

   This relay removes the earth from the finder's conductor from the starting end (FS1 or FS2), and connects this conductor to the booster battery of conductor 00. This conductor 00 corresponds to conductor 00 in fig.l, the booster battery being connected to this conductor by the Gold relay in fig.l. As was originally described, the Or relay opens the circuit of all the seeker switches, so that no interference can take place during the removal of the occupancy potential of the ç conductor. The booster battery applied to the conductor c operates the subscriber's meter in the ordinary way, such as MS in fig.l.



   The circuit of the link line may be arranged to facilitate repeated counting.



   Disconnection of the connecting line at its arrival end. Suppose first that a call has been extended from the right side of fig. 3 to the left side of this figure, and a local cord circuit, such as the one shown in fig.l, is connected to panel Br. On further assumes that the case of a permanent call takes place on the reason line, due for example to a fault on this line, or a fault on the subscriber's line, or even due to a permanent closed circuit created on this subscriber line. In this case, after a determined interval, the time switch, shown in fig. 2, causes

 <Desc / Clms Page number 31>

 the excitation of Yr and Zr (fig. 2) as has been described previously. Figure 5 can now be viewed as the left side of fig. 2.

   Earth will be applied to the two conductors shown on the right of fig. 5 through an easy to establish circuit.



   Another circuit is also closed through the automatic break contact of the stepping solenoid SM of the disconnect switch. The switch then begins to search for the faulty line.



   In the meantime, the operation of the relay Yr of FIG. 2 connects the battery as previously on the brush "d" of the line finder associated with the local cord circuit, that is to say that the battery is placed on the terminal "d" of panel Br in fig.3.



  The conductors a, b, c, d, associated with Br and shown below, are connected to the corresponding conductors a, b, c, d, shown in the upper left corner of Figure 5. We can therefore see that the circuit of Cord connects the Yr armature battery, fig. 2, to terminal d of the disconnector switch shown in figure 5.



   When the disconnector switch reaches the terminals marked with the desired potential, the relay Ar is energized by the battery of terminal d and stops the electromagnet step by step. Relay Br is energized, and by its right armature, it places the battery through the conductor. fig.5 on the conductor a of the connecting line. By its outer left armature, the relay Br connects the earth to the conductor b of the connection line shown in fig. 3. By its inner left armature it connects the earth to conductor 0 associated with the corresponding conductor in fig. 3. The relay Llr1 is energized through its right winding, and is blocked through its two windings in series on the closed circuit of the line.

   In addition, this relay Llr1 places the earth on the terminal o of the panel Br to free the cord circuit and make the line of the link occupied. Restoring the cord circuit removes the battery and earth from the connector switch, as was originally described. By the earth connected to the right armatures of Llr, the test terminal TT associated with the link line on the selector switches is placed in a condition.

 <Desc / Clms Page number 32>

 of occupation. Applying the 'battery to the conductor .µ¯ and the earth to the conductor b of the. link line by the disconnector switch, causes the change of direction of the current on this link line.



   When the time switch of fig. 2, leaves the contacts on which the disconnector switch was energized, the relays Dr and Ar of this disconnector switch are neutralized and the battery, as well as the earth, on the conductors a and b of the link line, are removed. . The Llr1 relays now lock up through a circuit passing through the battery, the two windings, Llr1 elements, the line circuit, the left outer armature of Llr1, a resistor, and earth. This resistor is provided to prevent the bypass of the battery to the conductor of the disconnector switch.



     Now considering the far end of the line, the change in direction of the current through the relays Zr, Xr, Ar, causes the reestablishment of Xr as a result of the opposition of the flows in the two windings. This reestablishment of Xr brings about that of the Fr and Br relays. By neutralizing itself, Br breaks all the connections with the researchers FS1 and FS2 at its three lower contacts.



  These are of the type in which there is no rest position, and therefore no return to the normal position takes place.



  By its upper contact, Br breaks Cor's blocking circuit, which is neutralized as well as the Dr and Mr relays if necessary. By its other upper contacts, Br opens the closed circuit through the link line, re-establishing the Ar relay. If now the link line is in order, no closed circuit exists on this line, and the blocking circuit previously plotted for Llr1 is open. When the disconnector switch is restored to idle at the terminating end, Llr1 is neutralized. The link line is thus in working order.

   If, on the other hand, the permanent closed circuit at the incoming end is due to the connection line itself, the distance from the closed circuit in Br has no effect, since an alternating circuit on the closed circuit, due to the disturbance, is planned

 <Desc / Clms Page number 33>

 for Llr1. This circuit kicks in when the disconnect switch at the terminating end is restored to idle. During this time, the earth connected to the conductor .1 ?. of the link line through the disconnector switch, causes Lr to operate at the outgoing end. A call is then created, and the trunk line is chosen on panel B .. by a local cord circuit.



  The following operations take place exactly as for a normal call, and unless the fault on the line is repaired before the scheduled period of time, i.e. thirty seconds, the trunk line is disconnected at the starting end, exactly as before, the two relays, disconnecting the line, locking themselves with their two windings in series with the earth at their external armatures by means of the closed circuit of the faulty line. The resulting rupture of this closed circuit easily causes the reestablishment of the two relays.



   If we suppose that the disturbance, or the permanent closed circuit which causes the disconnection of a connection line at the terminating end, is due to the subscriber line connected to the end of departure with switches FS1 or FS2, the reestablishment of this line, by neutralizing Br, causes the creation of a call at this end. The subscriber line is therefore seized by a local cord circuit, and if the call is not released, or if the disturbance is not removed, the line is disconnected after a period of time. defined, in the usual way.



   If it is assumed that a connection is made from the left side to the right side of fig. 3, the same series of operations takes place.



  It can be seen that in this case the excitation of Br1 places the earth of Arl so as to excite the line relay Lr through the conductor "b".



  Moreover, it can be seen that the battery applied to the conductor a and the earth applied to the conductor b of the disconnector switch further changes the direction of the current in the closed circuit, in order to release Xr1 and to excite Lr1 as before. Relays Llr1 and Llr, can be blocked if necessary. Except for the above, the circuit at both ends of the link line is iden

 <Desc / Clms Page number 34>

 tick and operates in exactly the same way.



   It is obvious that the relays Llr1 and Llr can include contacts by which operations can be caused to bring an alarm signal, either immediate or in time.



    CLAIMS.



   1 - Telephone system comprising means that come into action when a permanent closed circuit is created on a line, in order to put this line out of service.



   2 - Telephone system comprising means arranged in such a way that if a permanent closed circuit, or an earthing is created on a line, these means come into action to cause the restoration to the. normal position of devices connected to the faulty line.



   3 - Telephone system in which calls can be made between automatic or semi-automatic offices through junction lines, means being provided and arranged so that if a permanent closed circuit is created on one of said lines of junction, these means come into action to cause the decompression of said junction line at its two ends.



   4 - Telephone system in which means are provided and arranged in such a way that if a called subscriber releases his set while the calling subscriber remains connected to the line, said means come into action to restore the equilibrium. - device connected to the calling line after a certain time interval.



   5 - Telephone system in which calls are extended to other offices through two-conductor trunk lines, means being provided so that if such a trunk line is connected to a line on which a closed circuit is created permanent or other disturbances, these means come into action to restore the said junction line.

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


    

Claims (1)

6 - Telephone system in which a device is provided individually on each line, this device acting under the <Desc / Clms Page number 35> tion of other means when a permanent closed circuit or any other disturbance occurs on the corresponding line, and this in order to put this line out of service. 7. A telephone system according to claim 6, wherein said device is arranged to be released when said permanent closed circuit, or the other disturbance, ceases. 8- Telephone system according to claims 6 or 7, characterized in that said device comprises a relay which is blocked through the closed circuit: permanent created on the line. 9 - Telephone system according to claim 6 ,, 7 or 8, characterized in that said device, individual to a line, is arranged so that when it acts it causes a signal which indicates the presence of a circuit permanently closed or any fault. 10 - Telephone system in which calls are made by automatic or semi-automatic switching apparatus, means being such that if a disturbance occurs on a calling line, or if a permanent closed circuit is created on this line, a switch automatic acts to connect to the said line and put it out of service. 11 - Telephone system in which calls are set up by automatic or semi-automatic switching apparatus and in which a device is provided for disconnecting subscriber lines if necessary, said device also being arranged to disconnect at their two ends, junction lines connecting offices to each other. 12 - Telephone system according to any one of the preceding claims, in which the means making it possible to carry out said disconnections can also act to carry out the forced restoration of the associated devices. 13. Telephone system according to any one of the preceding claims, in which said means which serve for disconnection can also perform, under the control of the called subscriber, a re-establishment in time of the devices used for a connection. - xion. <Desc / Clms Page number 36> 14 - Telephone system according to any one of the preceding claims, wherein said means for disconnecting and re-establishing the devices a, ssociés with a line, also serves to achieve: the reestablishment of a calling line connected to a trunk line to the remote office. 15. A telephone system as claimed in claim 3 and some other of the preceding claims, wherein said interoffice trunk line is disconnected at the remote office by an arrangement which, when the trunk line is disconnected at the local office, creates a call. permanent at the far end, permanent call which is subsequently broken. 16 - Telephone system according to claim 15, wherein said trunk line between offices is disconnected at its remote end by a device similar to that used at the local end to perform the disconnection thereof. 17 - Telephone system according to claim 10, wherein said automatic switch connects to said lig ne under the control of a device in time, the latter being available. se to place the line in a certain condition, and to activate the switch in a search movement after a defined time interval. 18. Telephone system according to claim 17, in which said line is brought into the desired condition by creating a certain potential on the terminal to which said line terminates in the panel of a line finder, this potential being obtained by means of a local connector device connected to the line. 19 - Telephone system according to one of claims! 17 or 18, in which said terminal on which said potential is created is that used to designate a calling line to an operator or to another office. 20. A telephone system as claimed in claim 4, as well as in a few other of the preceding claims, and in which when said equipment is restored the calling line is taken out of service. <Desc / Clms Page number 37> 21. Telephone system according to claim 19, in which said subscriber line is disconnected by the same device as that which restores the corresponding equipment. 22. A telephone system as claimed in claim 3, 10 or any other claim, wherein means are provided such that when any fault or permanent circuit is cleared, the disarmed line is automatically released. 23 - Telephone system according to claim 5, wherein said forced re-establishment of a calling line at the remote end of said trunk line is effected by devices arranged to disconnect this trunk line at its local end and to create a call at the far end. 24 - A telephone system according to claim 23, wherein said trunk line is released when the calling line is disconnected. 25 - Telephone system comprising trunk lines between offices, according to any one of the preceding claims, and in which disconnection means operate on one of these trunk lines in either direction. 26 - Telephone system including trunk lines. between offices, according to any one of the preceding claims, in which said means for effecting forced restorations act in either direction of said connecting lines. 27 - Telephone system comprising junction lines between offices, these lines being so arranged that the line relay at one end is connected between a conductor and the earth, while the line relay at the other end is connected between the other conductor and the battery. 28. A telephone system according to claim 27, in which relays are provided by which said joy line can be kept occupied, these relays being both connected between the same conductor of the trunk line and battery. <Desc / Clms Page number 38> 29 - Telephone system, in which trunk lines, acting in both directions, connect offices, the circuit on one of these lines being closed at the outgoing end by a differential relay, so that the change of direction of current at the far end in this circuit will restore the associated devices and create a call at that end. 30 - Telephone system according to claim 29, wherein said closed circuit is established by a counter relay, the application of a booster battery to the remote end of the line thereon being used to actuate this relay. 31 - Telephone system in which means are provided by which a supervisory signal is transmitted from a local office to a main central office, and in which other means are provided by which an existing connection to the central office is broken for this purpose. 32 - Telephone system in which means is provided for transmitting a supervisory signal from a local office to a main central office, and in which said means is the same as that used to determine the elapsed time intervals between various stages of the connection. 33. The telephone system of claims 31 or 32, wherein said means for transmitting a signal from the local office to the central office includes a device by which the battery and earth are applied, at certain time intervals to the central office. 'one or both sides of the line. 34 - telephone system, according to claims 31, 32 or 33, wherein the means for breaking a connection also serves to transmit said supervisory signal. 35 - Telephone system arranged and functioning as described above and as shown in the accompanying drawings. 36 - trunk circuit acting in both directions, suitable for use in telephone systems arranged and operating as described above and as shown in the accompanying drawings, <Desc / Clms Page number 39> 37 - Arrangement for disconnecting lines and for effecting the restoration to normal state of apparatus in telephone systems arranged and functioning as described above, and thus / is shown in the drawings above -seals. 38 - Time apparatus usable in telephone systems, arranged and functioning as described above, and as shown in the accompanying drawings. ABSTRACT. The invention is particularly concerned with automatic central office telephone systems capable of communicating with small rural offices which are sometimes left unattended. By the arrangements described, a forced restoration, to the normal position, of the devices used by a connection, is achieved when a permanent closed circuit, or any other disturbance, occurs on a subscriber line or a trunk line and this The faulty line is then automatically put out of service until the fault or the closed circuit is removed.