US990468A - Telephone system. - Google Patents

Description

P. G. AGRELL.

TELEPHONE SYSTEM.

APPLICATION FILED FEB.15, 1908.

Patented Apr. 25, 1911.

2 SHEETSSHEBT '1.

YI H II GZ a/Qa/ W 6] Wue wto a 51% LL Gr l'o'm P. G. AGRELL.

TELEPHONE SYSTEM. APPLIOATION'IILED 212.15, 1908.

Patented A131; 25, 1911.

2 SHEETS-SHEET 2 Q Wmmw 75 /f 414M41 UNITE STAES Aunt TELEPHONE SYSTEM.

Specification of Letters Patent.

Patented Apr. 25, 1911.

Application filed February 15, 1908. Serial No. 416,072.

To all whom it may concern:

Be it known that I, FRANS GUNNAR AGRELL, a subject of the King of Sweden, and resident of Stockholm, Sweden, have invented certain new and useful Improvements in Telephone Systems, of which the following is a specification.

- This invention relates to telephone systems and more particularly to that class usually designated as call distributing systems, where a calling subscriber is by means of a distributing operator, or other means, connected to a switching circuit controlled by an operator that is not busy at the time, in order to equalize the work among and eventually decrease the number of operators.

One of the chief objections to such a system as heretofore devised has been the difficulty to adapt the same for party line servlce.

In a call distributing system the operator does not know the number of the calling subscriber and, consequently, if a subscriber should call up a party on his own line (re vertedcall) the operator would find the corresponding multiple jack indicated busy and consequently be unable to handle such a call. The only way in which a reverted call can be handled with the present call distributing systems is that the operator upon findin the wanted subscribers ack busy asks the calling subscriber for his number to ascertain that the wanted subscriber is not on the same line as the calling. This method will, of course, lead to delays in handling the-business so that the advantages of using the distribution system would be more or less off-set.

One of the objects of my invention is now to remedy the defect mentioned by the employment of means adapted to automatically indicate to an operator that she is handling a reverted call'as soonas she tests the jack of the calling subscr ber.

In carrying out my invention in a coniplete telephone system other new objects and results have been 'accomplished One of said new features is that the calling cord has been provided with only two indicators alternatelyservmg as call, reversed call and supervisory syqnals. In systems heretofore devised a separate indicatorv has been em ployed for each signal.

Other objects of my invention will be in part obvious and will in part appear hereinafter in connection with the drawings accompanying this specification in which I have illustrated one form or embodiment of my invention in a common battery exchange system with a combination of circuits and devices, many of which may be altered to meet the various requirements of telephone service and to adapt the same for use with other systems.

Figure 1 is a diagram showing the connections of an embodiment of my invention in a manually operated common battery system. Fig. 2 shows diagrammatically the connections of an embodiment where the dis tribution is performed. by automatically operated means, that is without the help of a distributing operator.

In Fig. 1, at 12 is shown a party line having party stations 8 at the one end and carrying the local jack at, and multiple acks 5 at the other end. The line is normally supplied with current from the common battery over the resistance (3 on the one side and the line relay 7 on the other side. The line relay and the resistance can be cut away from the line by means of the cut off relay 8, the winding of which is connected on the one side to the third conductor 9 in the multiple, on the other side to ground. This third conductor 9 is connected to the sleeves of the local jack at and the multiple jacks 5. In the diagram one cord circuit drawn in heavy lines coln'iecting the answering plug 10 and the calling plug 11 is shown. The answering plug 10 is positioned in a separate distribution board having a number of answering cords 1 fl leading to different operators and a number of local jacks l. The calling plugs 11' are situated at multiple boards having no local jacks. At each answering cord is a signal, in the drawing shown as a lamp 12, for indicating whether the operator controlling the calling end of said cord circuit is'busy or not and a disconnection signal 13, also indicated as a lamp, is provided for signaling the distribution operator that the connection shall be taken down. The l al jacks 4 are associated with signals shown as calling lamps 14. When a subscriber upon the line ].2 calls up, for

instance, at the station 3*, current will go from the battery 35 over lead 15, resistance (3, contact 16 of the cut off relay 8 to the one. side 1 of the line and back through the subscribers instrument, the other side 2 of the line, the contact 17 of the cut-otf relay and the'line relay 7 to ground. The line relay will thus operate closing its contact 18 so that current now goes through the line lamp 14 indicating the call. The distributing operator now lifts up a plug 10, leading to an operator that is not busy at the time, as indicated by the busy lamp 12, and places the same in a jack 4 thus connecting the subscribers line to the cord circuit. 011 plugging into the calling line the relay 45 is energized by current over the circuit 19, 44 ring side of cord through the local station back through the tip side relay 45 to positive pole of battery. The contacts- 52 and 50 are broken. The distributing operators part in the connection is now performed and current' goes from the battery over lead 19, winding 22 of a relay 23, sleeve conductor 24 of the answering cord to the sleeve of jack 4, third conductor 9 of the multiple and the cut ofi relay 8 to ground and back to battery, indicating all the multiple jacks 5 of said line busy and operating the cut oil relay 8 and the relay 23. The cut oil relay opens the contacts 16 and 17 breaking away the resistance Gand the line relay 7 from the line so that the line relay ceases to operate and, consequently, the line lamp 14 goes out. The relay 23 when operating closes the contact 25 so that current goes from battery o'ver lead 19, contact 25, lead 27 and the lamp 49, lead 26 and contact 51 of relay 47 to ground and back to battery, lighting the lamp 49 and thus indicating to the operator controlling-the plug 11 that a call is upon the cord circuit. Now the operator controlling plug 11 notified by said signal connects her talking set "t0 the cord circuitby throwing the key 34. The talking set and the parts of the key belongin to the same have not been shown in the d necessary for understanding the operation of the invention. When key 34 was thrown contacts 39 .and 40 closed, contact 40 connecting the battery lead 19 to a common lead 31 which branches to all the lamps 12 belonging to cords controlled by this particu lar operator. The other. side ofthe lamps 12 are by means of the plug contact 33 connected to ground so that the lamps 12 at such cord circuits as have not had theplug lifted from the seat will light indicating that the operator is busy and that the cord should not be used. I 1

When contact 39 closed, current went from battery over lead 19, Winding 36 of relay 23, 55

resistance 37, lead 38-and contact 39 of the key 34 to ground and back to battery. This winding 36 is opposing the winding 22 of same relay andthe resistance 37 is so selected that the current in winding 36 neutralizes the effect of winding 22 so that relay 23 ceases to operate, breaking contactf25 and thus causing the lamp togo out. The

operator now asks for the number wanted and tests the corresponding jack in the multi ple.

Supposing now that the subscriber lagram as they are unwanted to talk to a party upon his own line, the operatorwould then find jack 5 busy as the same is connected to battery over the winding 22 of the relay 23, but at the same time the testing current would increase the current in 22 sothat said winding is no of my invention. It is only necessary to assume that the sleeve of the jack 5 is touched by a grounded conductor, for instance, the

tip of the plug 11. Current will flow through the relay 47 to ground, completing a circuit from the conductor 9 in parallel with that I through the relay 8, causing an increased flow of current in the winding 22 of the relay 23, but will not operate the armatures of the relay 47.

When the operator after having ascer tained that the jack 5 is not actually busy places the plug 11 into the said jack current will go from battery over lead 19,,re1ay 21,

sleeve conductor 41 to the third conductor 9 'of the multiple and through the cut off relay to ground, regardless of whether said jack 5 belongs to the same line as the callr ing subscriber or not.

Now the relay 21 operates, closing its contact 20, which is in shunt with contact 25.01? relay 23 so that said relay has no effect upon the signals as long as the'connection is made. The relay 47 will be energized over the calling line,

breaking contact at 51 and preventing the: light-ing of lamp 49. When the operator after having finished the connection throws back the key 34 all the lamps 12 connected to said key will go out so that the operator is indicated free to take a new call,

The'cord circuit ha;s',been provided with wellknown means for-supplying current to the subscribers instruments during conversation, namely, the retardation coils 44 and 45 connected to the answering end of the cord circuit and'the retardation coils .46 and 47 connected to the calling end of the cord.

circuit and the two sides of said cord circuit are connected by means of condensers. .The two retardation coils 45 and 47 have been arranged as relays and serve as such for facilitating the supervision of the call and the disconnection. For supervising the call two lamps 48 and 49, of which 49 as before described also serves as callin call signal, are arranged at t e calling plug.

and reversed both connected to -battery over contacts 20 not relay 21 and 25, of relay 23 and connected to ground, over the contacts 5 O-of relay. 45

and contact 51 of relay47, respectively, so.

that if any subscribenshould hang his re:

ceiver up, the. corresponding lamp will ,light.w I The disconnection lamp l3 at the answering end of the cord circuit is connected to battery over the contacts 52 upon relay 45 and 53 upon relay 47 -in series and is connected to. ground through the plug contact 54 when the plug is up so that said lamp will light as soon as both subscribers have hung up their receivers.

- It is not thought necessary to further trace the difliere-ntcircuits as the same will be evident from an-inspection of the diagram.

The embodiment of my invention as shown in Fig. 2 is'distinguished from the one just described only by the automaticallyv operated means employed for connecting 'the calling line to the answering end of the cord circuit and for severing said connection after the conversation is finished. I

been fully described in my co-pending applications Ser. Nos. 339,521 and 386,901. Any other devices which fulfil the requirements of the system could, of course, be used 7 instead of the aforementioned devices, as the mechanical arrangement of the connector is to a certain degree non-essential to the operation ofthe system and it is not thought" necessary to describe the connector here further than to state that the pivoted arm 55 carries terminals 58 and 59 adapted to engage terminals 60 and 61 carried by another pivoted arm 56, there being as many arms 55 as there are subscribers to be accommodated by the device and as many arms 56 as there are cord circuits assigned to said group of subscribers. The different arms are so positioned that the terminals of any one of the arms 55 may engage theterminals of any one of the arms 56 under certain conditions. An eleotro-magnet 7, COrIespOTlding to the line relay of Fig. 1, operates the latch 62 to release the arm 55 which then will fall in the direction of the arrows. The terminals 60-61 are so positioned that the same are out of reach for the terminals 58--59 during this falling movement but the arms 56 can be moved in towardthe center by means of clectro-magnets 63 so that the terminals may be engaged by a falling member 55.

The motor 57 operates in a manner fully described in the aforesaid applications to restore the man 56 to its original position when disconnection shall take place.

As in the diagram, Fig. 1, a party line 1 -2 having party stations 3 extends in'the exchange to multiple jacks 5 and isalso connected to the terminals 58 corresponding to the tip and ring contacts of the local or calling jack of Fig. 1. The line is normally connected to battery-over the resistance 6 and contact 16 of a cut oft relay 8 on the one side and'over line relay or electro-magnet 7 and contact 17 upon the cut off relay on the other side. The cut ofi relay 8 is connected to ground on theone side and to the third conductor 9 of the multiple on the other side, which conductor is connected to the sleeves of the multiple jacks and to the contact 59 of the arm 55, which contact corresponds to the sleeve of the local jack 4: in Fig. 1.

The switching circuit which corresponds to the cord circuit of Fig. 1 is arranged similarly to said circuit. The contacts 60- 61 of the arms 56 correspond to the local plug 10 of said circuit and the only diiter- 'ence lies in the means for automatically operating said terminals.

' As before mentioned the terminals are normally out of reach of the terminals 58-59 when falling, but can be brought into an engaging position by means of the electron'iagnet 63 operating the arm 56. To this end the electromagnet 63 is on the one side connected to a contact 64 so situated that a contact maker or brush 65 upon the arm 55 sweeps over the same when the terminals of said arm approach the terminals of arm 56. It said arm, like the one of the drawing, is not busy at the time current will flow from battery 35 over the lead 19, the contact 66 of the operator busy relay 30, the contact 67 of the relay 21 and the lead 68 to the magnet 63 and from there over lead 69, contacts 61 and-65 to ground and back to battery so that the magnet 63 will operate moving the arm 56 to its inner position where the terminals 58 and 59 make contacts with the terminals 60 and 61. New current flows, from battery over the lead 19, the winding 22 of the relay 23, the lead 24, terminals 61 and 59 to the third conductor cut off relay 8 to ground cutting oil the battery over resistance 6 and relay 7 from the subscribers line. Relay 23 also operates, closing contacts 7 0, 71 and 72. Current now goes from the battery over lead 19, contact 71. lead 82, contact 73 of relay 21 and the lead 74- to the opera tor busy relay 30 and from there to ground. This relay 30 now operates breaking contact-66 thus cutting away the current from all loads 68 ot' the switching circuits controlled by this operator, so that the arm 56 goes back to its position of rest with its terminals still connected to the terminals of arm 55 and all the arms 56 belonging to said operamr are made inaccessible for any subgoes from the battery over lead 19 and con- 34, fiowsthrough the compensating winding tact 40 to the operator busy relay so that the busy relay will still bejoperated when relay 22 ceases to operate, which happens as soon as current, upon throwing the key 36, the resistance 37,- lead 38 and the con-- tact 39 to ground, Now the lamp 49 goes out.

If in the case of a revertedcall the operator should test the sleeve of a multiple jack however,

5, for instance, with the tip of the plug 11, additional current will flow over the winding 22 of the relay 23 so that the lamp 49 will light again, indicating the reverted call. When the operator after testing places the plug 11 into the jack 5, current will flow.

from the'battery over lead 19, relay 21, lead 41, the sleeveof the plug 11 and jack 5 to the third conductor :9 of the Wanted subscribers line indicating the same busy and operating its line relay 8 if the same should not, as in the case of the reverted call, be already operated. The relay 21' now operating breaks the contacts 67 and 73 and closes the contact 76 which connects the lead- 75 to ground, so that the lamps 48 and 49 now serve as supervisory signals governed solely by the operation of the relays 45 and 47.

hen the operator throws back the talking key 34, the compensating winding 30 will be disconnected from groundand thus the relay 23 will again operate putting an additional ground on lead 75, but not operating the busy relay, as the contact 7 3 as before mentioned .is broken. The operator busy relay 30 thus goes back to its of rest closing the contact 66 so thatthe operator can receive another call-upon another cord circuit. The busy arm 56 is, still unresponsive to any falling arm 58 asthe battery is cut off at contact 67 and will remain so as long asthe conver sation goes on.

In order to facilitate the automatical dis-.

connection of terminals 5859 and 60-61 in connected on one "side over contact of relay 23 to the battery and on the other side overcontacts 52-53 of the supervisory relays 45 and 47 to ground so that when both up their receivers said -re-' I aspecial disconnecting relay 77 has been put lay 77 will operate. This relay thencloses 81, of which contact.

the contacts 78, 80 .and

7 8 connects'the electro-magnet 63 to battery and contact 80 connects theother side of saidfimagnet to ground so that it brings theafrm 56 into its inner-position--where the position terminals 58 and 59 are disconnected from the terminals 6061 by the action of the restoring motor 57, the action of which is I contact 71 is broken so that the disconnecting relay ceases to operate and accordingly current is cut off from the electro-magnet 63 so that the arm 56 goes back to its position of rest. The supervisory lamps 48+49 still continue to light on account of the relay 21 still beingoperated, but when the operator severs the connection between plug 11 and,

jack 5 this relay also goes back to rest so ditions. r v 1 From the foregoing description of emthat everything' is restored to the initial conbodiments of my invention it will be seen that in a distribution system manually or automatically operated in accordance with the ideas herein set fortlrthe operator at the multiple board is automatically notified in case of a reverted call so that she may tell the calling subscriber to hang up his-res ceiverand thus be able to the wanted subscriber.

properly signal I As many changes could be made in the i tion designed without departing from the scope thereof, I intend that all matter contained in the above description or shown in the accompanying drawings shall be inter preted merely as an illustrative embodiment of my invention and not in a' limiting sense.

hat I claim is: I t 1. In a telephone system, the combination with a multi-party line, of a switching cir cuit extending between two differently located switching devices and adapted to be connected to said line at one of the switching devices when said line is calling and at the other switching device when to be called,

and means including a supervising indicator which is also arranged and adapted to 'indiat said last named I cate a reverted call switching. device.

2. In a telephone system, the dombination with a multi-party line, cuit extending between cated' switching devices and adapted to be connected to said line at one of the switching devices when said line is calling and at of a'switching i QWO difi'erently 1 the, other switching device when to be called,

and means including a supervising indicator which is also arranged and adaptedto auto matic'ally indicate named switching device.

a reverted call at said last 3; In a telephone system, the combination with amulti-party line, of cuit extending betweentwo differently loa switching cir I cated switch boards and adapted to be connected to said line at one of said switch hoards when said line is calling and at the other switch board when to be called, and means including a supervising indicator which is also arranged and adapted to indicate a reverted call at said last named switch board.

A it. In a teleplnine system, the combination with a inulti-party line, oi? a switching circuit extending between two differently located switch boards and adapted to be connected to said. line at one of said switch hoards when said line is calling and at. the other switch board whii he called, and

ieans including a supervising indicator which also a1 winged and adapted to automatically indicate a reverted call at said his named switch board.

in a telephone s; n, the combination a line of a switching circuit, automatiopt areal means adapted to connect line w .n one end or. said switch ng cirtor connecting the other end of ng circuit with another circuit, r including a supervising indicator n is also arranged and adapted to indiit said last nained end oi the switching it whether said circuit is connected to 1 line,

in a elephone stem, the combination with a line, of a s itching circuit, automatically operated means adapted to i connect said line with one end of said switching circuit, means or connecting the other end of said switching circuit with another circuit, id means including supervising indicator also arranged and adapted to indi- 1 said last named end oi the switching whether said circuit connected to me when attempt to connect said t named end with said line is made. 1. in a telephone system, the combination i a multiparty line, of a switching cirautomatically operated means for con- Jing one end or said switching circuit said line, manually operated 1116 ns tor rting the other end of said switching circuit with another rcuit, and means ineluding a supervising indicator which is also arranged and adapted to indicate a reverted 8. in a telephone system, the combination with a hue, oi means adapted toindicate said line busy by current flowing over said adapted to be energized by from another circuit, means for indicating means, a switching circuit adapted to connect with said line, means associated with said switching circuit and adapted to allow current to flow over said first named means and its shunt, a relay adapted to be energized by said current, a compensating winding upon said relay adapted to prevent the shunt current from energizing said relay, and a signal operated by said. relay.

9. in a telephone system, the combination with a line, of means adapted to indicate said line busy by current flowing over said means from another circuit, a relay shunting said busy indicating means, a switching circuit adapted to connect with said line, means associated with said switching circuit and adapted to allow current to flow over said first named means and its shunt, a relay said current, a compensating winding" upon. said relay adapted to prevent the shunt current from energizing said relay, and a signal ope ated by said relay.

10. In a telephone system, the combination with switching circuits extending between two ditl'erently located switchingdevices and adapted to be connected with a calling line at the one switching device and with a line to becalled at the other device of means including an indicator adapted to indicate that a calling line is connected or is going to be connected to said switching circuit, and means including the same indicator as that of the foregoing means for supervision of the call.

l1. Tn a telephone system, the (,Oll'lbll'iil tion with a switching circuit extending between two differently located switching devices and adapted to be connected with a niulti-pai y line at the one device when said line is calling and at the other device when to be called, of means incl uding an indicator for supervising the call, and means including the same indicator adapted to indicate a reverted call.

Signed at the city of New York in the coimty oi New York and State of New York means shunting said busy i this 28th day of Oct. A. D. 1907.

FRANS GUNNAR AGEELL.

ii itnesses LEWIS J. Doorir'rnn B. W. COULDOCK.

drew-steamers

Images