US910873A - Telephone ringing system for party-lines. - Google Patents

Description

G. A. SIMPSON. a'nnnrnonn meme sYs'rnn 1-01; mm Luna.

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Patented Jan. 26, 1909.

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wxvnasm UNITED STATES PATENT OFFICE.

CHARLES A. SIMPSON, OF CHICAGO, ILLINOIS ii SSIGNOR TO KELLOGU SWITCHBOARD AND SUPPLY GGMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE BINGING' SYSTEM FOR PARTY-LINES.

Patented Jan. 26, 1909 Application filed November 30, 1907.' Serial No. 404,684.

To all whom it may concern:

Be it known that I, CHAnLns A. SIMPSON, a citizen of the United States, residing in Chicago, county of Cook, and State of lllinois, have invented certain new and useful Imrovements in Telephone Rin ing Systems or Party-Lines, of which the ollowing is a specification.

My invention relates to part line telephone systems, and more particu arly to that class of s stems havin a bridged clearingout signa at the centre oilicc adapted to be actuated at the end of a conversation by current sent from a hand generator at tho subscribers station. In systcmsof this class it has become the practice to connect a number of subscribers instruments in parallel across the same telephone line. These instruments are each provided with a signaling bell, and in the s stem to which my invention particu larly re ates each bell is connected in series with a condenser of suflicient ca acity to pass the ringing current for the bel With former systems of this character, when the operator at the central oflice rung one of the bells -nn a line, she simultaneously charged and 1 scli arged all of the condensers wh ch were bridged across the line at the difi'crent substations. If in these systcn'is, the 0 erator released her ringing key at a time W ion the condensers of the various substations were highly charged, the discharge of these condensers would take place after the ringin key had returned to its normal osition ans would therefore pass through tie clearingout signal and momentarily energize that signal, causing it to be displayed.

It is the object of my present invention to overcome the difiiculty experienced from the discharge current from these condensers, and thereby to provide a circuit which is more crfect in operation and less liable to give alse signals than systems used in the past.

Other objects of my invention will be brought out in the Following description and claims.

My invention is illustrated in the accom- 'panying drawing in which a line having but one subscriber thereon is illustrated at the left hand side of the drawing, and a party line havin four subscribers thereon is illustrated at t ie right hand side of the drawing, thetwo bein adapted to be connected for conversation by the central oflicc ap )aratus.

The calling subscribers station No. 1 is e nipped with the usual apparatus consistin o? the transmitter 2, battery 3, induction CO1 and, generator 8, and in addition'thereto, the condenser 9 which is connected ermanently in series with the apparatus of tie set. The rare wires 10 and 11 extend from the subscribers station 1 to the central oilioe where the T pass through the series contacts 12, 13 and 14: of the answcrin and multiple jacks and terminate in the COl l of the line dro 15. The called subscribers line is similhrly equi ped, corresponding apparatus of this line sing dcsignat by like figures with the suffix The cord circuit for connecting the lines for conversation has the tip and ring conductors 18 and 19, each being respectively interrupted by condensers 20 and 21. The sle ve conductors 22 and 28 of the answering switch hook 5, receiver 6, annunciator 7 and calling cords are connected with the live pole of battery A through the non-inductive resistance 24. The clearing out signals in thesystem hero shown consist of the relays having the high resistance windings 25 and 26, one bridged across each end of the cord circuit, these relays being provided with the lock-windings 27 and 28 and with the con tacts 29 and 30 in the circuits of the clearing out lamps 31 and 32 The spring contacts of the two clearing out relays are connected together by conductor 33, this conductor bemg connected through the auxiliary contact 34 of the operator s listening key 35 to earth. It is customary in a four-party ringing system of the type here shown to use four separate sources of current 36, each adapted to be connected with the desired linethrough the contacts of the ringing key. These four ringing keys are connected in scrics, such that the actuation of one of the keys disconnects the plug of the calling cord from the other apparatus of the cord circuit,

live pole of battery A. Relay 42 controls the normally open'contacts 44 and 45, contact 44 being permanently connected with the sleeve strand of the cord circuit and contact being permanently connected with the tip strand of the cord circuit at a point back of the series contacts of the ringing key. In the operation of my system the calli subscriber turns her hand generator 8 an sends a current over conductors 10 and 11 through the series contacts 14,. 13 and 12 of the jacks and through the coil of the line drop 15, throwing the drop and indicating to the operator tha. a connection is desired. The operator therefore inserts her calling lug 16 into the jack indicated, throws her istening key 35 and inquires the desired number. The number being obtained, the operator tests the desired line in' the usual manner. If the line is busy its sleeve contact will be at a potential higher than that of earth and a current will flow over the tip of the cord and throu h the operators head receiver and the thin? conductor connected therewith to earth giving a click and indicating the busy condition. Considering,

however, that the line is idle, the operator inserts her calling plug 17 and actuat'es the key which is adapted to ring the bell at thedesrred subscriber s station. The actuation of this key closes the circuit from the generator over the tip contacts of the plug and jack, line conductor 11, condensers 9', annunciators 7, line conductor 10', the ring contacts of the j ack and plug, the spring 39 of the operators ringing key and contact 41 to earth. At the same time current will flow from the battery A through onductor 43, the coil of relay 42, contact 40, pring 39 and contact 41 to earth, thereby actuating relay 42 and closin its contacts 44 and 45 thus com leting as out between the ti and ring con uctors of the cord circuit. pon the release of the operator's key the stored up ene from thecon enser's 9' is allowed to disc arge over the line conductors 10' and 11, the tip and ring contacts of.;

the jack and plug, the series contacts of the operator's ringing key and'the shunting contacts 45 and 44 of relay 42. This prevents current from these condensersfrom passing through the actuating coil 26 of disconnect relay. The relay 42 is preferably made. slow acting by any of the well known methods such as inclosing its core in the copper shell. 37.

When the conversation has been terminated the subscriber's rotate their hand generators 'and thereby send current over the line conductors and tmough the coils 25 and 26 of the disconnect relays associated respectivel with the answering and ulallrng ends of t e cord circuit. When these relays are actuated the circuit is com leted from the live pole of battery A throng the lamps 32 and 31 and through the contacts 29 and 30 and the contact 34 of the operator's listemng key to ground, thus displayin the lam 32 and 31 A circuit is sirnu taneous y completed from the live pole of battery A through the locking coils 27 and 28 of the disconnect relays an through the contacts 34 of the operators listening key to earth. The operator seeing the signals 3.1 and 32. displayed removes her answering and calling plugs from the jacks of the line and then presses her listening key opening the con tacts 34 and releasing the disconnect signals 31 and 32. The lines are now again in their normal condition and ready for a second call.

It is to be understood that the clearing out signals here shown and described are of typical form and may be simp}y ordinary c caring out dropsor may be 0 any other desired form, and that many other variations from the system shown and described may be made without departing from the spirit or scope of my invention.

I claim:

1. In a telephone system, the combination with a telephone line having a bridged condenser thereon, of a cord circuit to connect therewith havmg a. bridged clearing out signal, a source of ringing current at the central office, means to connect said source with the' telephone line for signaling, and means to divert the discharge current from said condenser from the coil of said clearing out signal after ringing, scribed.

2. In a telephone system, the combination with a telephone line having a bridged condenser and annunciator, of a cord circuit to connect therewith ha a clearing out signal, a source of ringing current, and neans to connect said soiurce with the line or si na' u oses, an means to revent the d isch d r gd c ib-rent from said cohdenser from passing through said clearing out signal after ringin substantially as described.

3. In a te ephone system, the combination with a telephoneline having a bridged condenser, of a cord circuit to connect therewith havi a bridged clearing out signal, a source of ringing current, a ringing key and means to complete a shunt about the coil of said clearing out signal to'receive the discharge current from said condensers after ringrnig, substantially as described.

4. n a telephone system, the combination with a telephoneline having a bridged condenser, of a cord circuit having a bridged clearing out signal, a source of ringing current, a ringing key and means operated by the actuation of said key for cornpleting a circuit for the discharge current of said condensers after ringing, substantially as described.

5. In a telephone system, the combination with a telephone line having a bridged condenser, of a cord circuit having a bridged substantially as declearing out sigfial, a splurc lof 'ng gurrent a ringing ey an a re ay a apte to a chest siaost the steering out sighal or a short time after ring substantially as described.

6. In a telephone system, thecombination with a line having ca acity, of a cord circuit ,cord circuit having a signal receiving device, a rmgmg key, a relay, said key having contacts in the circuit of the coil of said relay,

and said relay having contacts in the circuit ol' the discharge current from said capacity, substantiallv as described.

8. In a telephone system, the combination witha telephone line havin capacity, of a cord circuit having a brii ged signal receiving device, means to charge the capacity of the line and means to divert the discharge current from the line from the brid ed si nal receiving device, substantially as eseri ed.

9. In a telephone system, thecombination with a telephone line having reactance of a signal recelvin device connected with said time which could be actuated by an impulse of reactance current, and means to prevent the reactance current from the line from passing through said si nal receiving device, substantially as dBSCII ed.

10. In a telephone system, the combination with a telephone line havin capacity, of a'signal receiving device bridge between the lim s of the line at the central office adapted to be locked in actuated condition by an impulse ofcurrent, and means to prevent the discharge current from said ca acity from actuating said signal, substantially as described.

11 In a telephone system, the combination with a telephone line having reactance, of a signal receiving device having its coil bridged between the limbs of said line at the central office, and means to prevent the reactance current from the line from passing through said si al receiving device, substantially as descri ed.

12. In a tele hone system, the combinatibn with a cor circuit, of a signaling device associated therewith, and a slow-acting rela adapted by its retarded action to maintain a shunt about the coil of said signaling device for a short duration of time, substantially as described.

13. In a tele hone system, the combination with a telep lione line having a reactance, of a cord circuit adapted to connect there with, a signal receivin device associated with the cord circuit an a slow-acting relay adapted by its retarded action to prevent the reactance current from the line from passing through said si al receiving device, substantially as descri ed.

14. In a telephone system, the combination with a telephone line of a cord circuit to connect therewith, a ringing key for the cord circuit, a bridged signal recelvmg device, and means to maintain a shunt about the coil of said signal receiving de vice for a short duration of time after the ringing key has been returned to its normal position, substantially as described.

15. In a tele 'hone s 'stem, the combination with a cor circuit aving a bridged signal receiving device, a ringing key for the cord circuit a slow-acting relay adapted to be ener ized by the actuation of said ringing key an the actuation of said slow-acting relay being adapted to complete ashunt about the coil of said bridged signal receiving device, substantiall Y as described.

16. In a telep lone system, the combination with a telephone line having rcactance, of a locking relay at the central ol'lice, a signal cr.-.nt1'olld by said relay, and means to )10- vent the reactance current from said his from actuating said relay, substantially as described.

17. In a telephone system, the combination with a cord circuit, of a locking relay having its initial operatin coil bridged across the line, a second coil therefor adapted to be energized over a local circuit to maintain the actuation of said relay, and means to prevent discharge current from the line from initially actuating said relay, substantially as described. a

Signed by me at Chica 0, county of Cook, and State of Illinois, in t is presence of two witnesses.

CHARLES A. SIMPSON. Witnesses:

CLIFFORD C. Bnann'oar MAR-loam E. Game.

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