US1357303A - Reverting-test circuit for telephone systems - Google Patents

Description

M. B. STAZAK. REVEBTING TEST CIRCUIT FOR TELEPHONE SYSTEMS. APPLICATION FILED APR-27. 1914.

1,357,303, Patented Nov. 2, 1920.

2 2755555. 51/522252 Jz/Zz'afiasZfl 52525.4.

UNITED STATES PATENT OFFICE.

MICEIAEL B. STAZAK, OF CHICAGO, ILLINOIS, ASSIGNOR- TO KELLOGG SV/ITGHBOARD AND SUPPLY COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

REVERTING-TEST CIRCUIT FOR, TELEPHONE SYSTEMS.

Specification of Letters Patent.

Patented Nov. 2, 1920.

Application filed April 2'7, 1914. Serial No. 834,638.

1 '0 all whom "it may concern:

Be it known that 1, MICHAEL B. STAZAK, a citizen oi: the United States at America, residing in Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Reverting-T est Circuits or Telephone Systems, of which the following is a specification.

My invention relates to telephone systems and has to do more particularly with a reverting busy test by which the operator receives a distinctive busy signal when a test is being made at a jack multiply connected with the jack in which the answering plug has been inserted, an object being to provide an improved and simplified circuit arrangement which is positive in operation.

.vfly invention is illustrated in connection with an operators cord circuit which is arranged for automatically cutting in the operator s telephone with the cord circuit when an answering plug is inserted into a jack of a calling line, and for automatically disconnecting said operators telephone when the connection is completed by the insertion of the calling plug into a multiple jack of the called line. My invention may also be used with an operators cord circuit which is arranged for manually connecting the operators telephone with the cord circuit by the actuation oi a listening hey, the reverting tone test operating as when used in connection with a cord circuit as described above, but I do not wish to be limited to the specific circuit arrangements illustrated as l contemplate using said test in connecti on with. other cord circuits.

For a more complete understanding oi my invention reference may be had to the accompanying drawing in wh1ch-- Figure 1 illustrates the reverting busy test used in connection with a cord circuit which is provided with automatic listening.

2 illustrates a cord circuit similar to Fig. l but with a listening key bridged across the cord conductors for manually connecting the operators telephone.

Referring now more in detail to the system which embodies my invention as illustrated in Fig. 1, it comprises a calling substation A connected by the line limbs L with a line circuit B comprising a line relay LB, a cutoff relay CO, line signal 1 and multiple jacks J. I have shown party line terminals 1), E and F connectedto the line L for party line service.

The cord circuit 0 comprises an answering plug r and a calling plug P condensers 2 and 3 being interposed in the tip and sleeve conductors connecting the plugs and P The answering end of the COICl CIICUIlJ comprises a tip answering supervisory relay TA and a sleeve answering supervisory relay SA, the two relays controlling the answering supervisory signal 4c. The sleeve supervisory relay SA has contacts 12-, i l actuated upon insertion of the answering plug into the answering jack for connecting the operators telephone with the cprd circuit. The calling end of the cord circuit C comprises a tipcalling supervisory relay TC and a sleeve calling supervisor relay SC, the two relays controlling the su pervisory signal The sleeve calling supervisory relay SC has contacts 10, 21 actuated upon the insertion of the calling plug P into a jack of the called line for auto matically disconnecting the operators set from the cord circuit. A party line key BK is provided which, when any one of the four key plungers is depressed, connects any one of the four ringing generators G, (P, r or G which is associated with the called substation, for signaling the said substation.

To the right of the drawing 1 illustrate a substation A similar to that illustrated at substation A, and being connected by line limbs L to a line circuit B 'similar to the line circuit l3 and bearing the same reference numerals but having the suflix prime. 1 also show party line terminals D E and F The reverting busy test circuit T'l com prises a comparatively high resistance reverting test relay RT, common to an opera tors position, which is actuated whenever the operator inserts an answering plug into an answering jack. A test relay T is also provided which is actuated whenthe operator tests a multiple jack of any busy line but which is effective only when testing a jack of a calling line.

When aparty calls for another party on the same line and the operator tests, relay i energizes and due to the shunting effect of the comparatively low resistance of the circuit including its winding and resistance 18, relay RT de'elnergizes, and therefore relay RT being deenergized and relay T energized, the special tone is connected in circuit with the third winding of the induction coil and thus through the operators receiver. The high resistance of relay RT also'prevents relays RT and SA from loclr ing up in series through contacts 10, 12.

When a busy line different than the calling line is tested, although relay T is en ergized, it is not effective because relay RT remains energized and only the ordinary busy cliclr is received by the operator.

In practice I have iiound that when operating on twenty-four volts the following sistances give a successful operation. Relays TA, SA, TC and bi 100 ohms. Relay RT, 3100 ohms, relay T, 300 ohms and coils 18 and 20, 50 and 300 ohms respectively. Relay Lit, 1000 ohms and relay GO, 500 ohms. These values are 'iven for purpose of illustration and it is to be understood that they may be varied and still give satisfactory results.

Assuming now that a subscriber at su station A wishes to converse with another subscriber, say at substation E for instance located on the same party line with A, the subscriber at A removes his receiver from the switch-hook causingth energization of the relay L of the line circuit B which at tracts its armature to close its alternate contact to light the line lamp 1. The operator inresponse to signal 1,. inserts an answering plug P into the jack 5 of the called line. Relay SA of cord circuit C and relay Ci) of line circuit B are energized in series from battery through relay SA, the sleeve con tacts of the plug P and jack J through the winding of relay CO to ground. The relay C0 operates and opens the'circuit of the line relay LR, deenergizing the said relay LR and eii'acing the signal 1. The relay TA of cord circuit C also operates from battery through the relay SA, sleeve contacts of the plug and jack J, one line conductor of the line L, through substation A,'the other line conductor of the line limbs L,tip contacts of jack J and plug P through relay TA to ground. Relay TA energizes opening its normal contact to prevent the signal l from lighting.

The high resistance reverting test relay RT of the tone test circuit TT is also 0perated from battery through the relay SA, normal contact 1O, conductor 11, alternate contact 12, conductor 13, through relay RT to ground, the said relay ET energizing. The relay SA was energized, as will be remembered, When the answering plug P was inserted into the jack J and said relay closed its alternate contacts 12 and 1a to connect the operators telephone O.

The operator having received the number from the calling subscriber, tests a multiple jack of the called line to, determine its idle or busy condition perhaps not knowing that the called subscriber E is located on the same party line with'calhng subscr1ber A.

The operator in testing places the tip of the plug P against the sleeve of a multiple jack of the wanted substation E in the usual manner. The sleeve of the jack being at a battery potential above ground which is extended from battery through relay SA of said circuit C over the sleeve conductor of the cord circuit, the relay T is energizedfroin battery at the sleeve of the tested ack, the tip of the plug P normal contact 15,'test conductor 16, winding of relay T to ground, said relay closing its alternate contact 17. The high resistance relay RT thus is shunted by the low resistance circuit including resistance 18 and relay T, which shunt can be traced from round at relay T through low resistance 18 and winding of relay T, test conductor 16, normal contact 15, tip of plug P sleeve of the multiple jack, sleeve conductor of the cord circuit C, normal contactlt), alternate contact 12, conductor 13, to relay'RT. The relay 1 1T therefore deenergizes and closes its normal contact 19 to connect the reverting test tone which may be traced from ground through the secondary winding of coil 9, imper ance 20, normal contact 1,alternate contact 17, through the third winding or" operators induction coil to ground, the tone being induced into the secondary oi the operators induction coil and through the circuit including her head receiver. T place the i111: pedance 20 in circuit with the reverting tone test to reduce the tone so that the operator will not receive a harsh tone in her head receiver.

1 This special tone indicates to the operator that she has tested a multiple jack which is associated with the jack in which the an swering plug is inserted. The operator then notifies the calling subscriber at substation A to replace his receiver upon its switch-hook so that she may ring the caller for subscriber The operator will then insert the calling plug P into a'jack or" the said line which in this case would be the jack J, after having removed the answering plug P. SC is therefore energized closing circuit for lamp 5. The operator will then signal the called-for subscriber on the party line by depressing the proper ringing hey. Upon both subscribersremoving their receivers the substations A andE are ready for conversation. Upon replacing their receivers the usual'disconnect signal is given and the op erator Withdraws the plug.

Assuming now that the subscriber at substation A wishes to converse with a subscriber at substation A the operation of this circuit is the same as previously described,

the relay C0 of: the line circuit B, the relays SA and TA oi the cord circuit C and the high resistance relay RT of the tone test circuit TT operate as before described, the operators set U being'automatically con- The relay nected to the cord circuit so that the operator may ascertain the wants of the calling subscriber. She then takes the plug P tests the multiple jack J of the called line as to its idle or busy condition. If the line is busy there will be a battery potential upon the sleeve of the multiple jack J from another cord circuit, said battery energizin the test relay T of the tone test circuit T'l, but as the high resistance reverting test relay RT energizes in every case when the operator plugs into a calling line, the tone test is not put in circuit by reason of the contact of relay RT moving to its alternate position but the operator receives the customary click in her head receiver notifying her that substation A is in use. If idle, she inserts the plug P into the multiple 'ack J The cut-off relay CO and relay S of the cord circuit C operate in series. The contacts 10 and 21 of the relay SC assume their alternate position automatically dis connecting the operators set 0 from the cord circuit C. This interrupts the circuit for the high resistance relay RT. of the tone test circuit TT the said relay deenergizing. The contact 15 of the relay SC opens its normal contact interrupting the circuit of the relay T, the said relay SC closing its alternate contact 22 and completing the continuity of the tip conductor. of the cord circuit G. The operator then depresses the proper ringing plunger connecting the proper generator to the tip side of the line to ring the called for subscriber. The supervisory signal 5 is lighted upon the closing of the alternate contact 22, the signal 5 remaining lighted until the called-for subscriber answers when the relay T C operates to open the circuit of the signal 5.

Upon termination of conversation the subscribers at substations A and A replace their receivers upon their respective switchhooks which act causes the deenergization of relays TA and TC and closes circuit for the signals 4 and 5, the said supervisory lamps 4c and 5 lighting and notifying the operator that the subscribers at substations A and A have replaced their receivers. The operator then takes down the connection deenergizing the relays SA and SC and effacing the signals 4 and 5.

In Fig. 2 I have illustrated an operators cord circuit C similar to the one illustrated in Fig. 1 withapparatus similar and bearing the same reference numerals but with suffixes added. The answering end of the cord circuit C comprises the relays TA and Sr the relay SA being without contacts for automatically connecting the operators set. The calling end of the cord circuit 0 comprises the relays TC and SC the relay SC being without contacts for automatically disconnecting the operators set. In Fig. 2 I show a listening key IK bridged across the conductors of the cord circuit C which, when actuated, connects the operators set with the cord circuit C The tone test circuit TT as illustrated in Fig. 1 performs the same function when operating in connection with Fig. 2 as in connection with Fig. l. I show the conductors which connect the operators telephone extending from the listening key LK and also the test conductor from the test contact of relay S0 The high resistance relay HT is operated, when the operator throws her listening key after an answering plug has been inserted into an answering jack, from battery through the winding of the relay SA the alternate contact 23 of the listening key LK, conductor 2%, through the winding of the relay RT to ground. The reverting tone test circuit operates the same when used in connection with cord circuit C illustrated in Fig. 2 as when used in connection with cord circuit of Fig. 1, the only material diiference being that in Fig. 1 the operators set is connected automatically and in Fig. 2 it is connected manually by the use of the operators key.

Having described my invention what I claim as new and desire to secure by United States Letters Patent is:

1. A telephone system comprising a calling telephone line, multiple jacks therefor, a cord circuit having an answering terminal connected to one of said jacks, an operators telephone, a reverting test relay for said cord energized responsive to connection of said operators telephone to the cord, a test relay connected to the calling terminal of the cord energized responsive to. the connection of the calling terminal to another one of said jacks, such connection being also eifective to deenergize said first relay, and a test tone connected to said operators telephone responsive to deenergization of the reverting test relay and energization of the test relay.

2. A telephone system comprising a calling telephone line, multiple jacks therefor, a cord circuit having an answering terminal connected to one of said jacks and tip and sleeve conductors connecting the answering and calling terminals thereof, a revertingtest relay, circuit connections for energizing and connecting said relay to the answering sleeve conducton a-test relay energized responsive to the application of the calling terminal of the .cord to another one of said jacks, such application also being effective to cause deenergizatio'n of the reverting test relay, and a test tone connected to said operators telephone responsive to the last said operations of the relays.

3. A telephone system comprising a telephone line, multiple jacks therefor, acord circuit, reverting test and test relays for the 7 for energizing the reverting test relay, means responsive. to a test of said line for deenergizing said reverting test relay and energizing said test relay, and a test tone connected to said operators telephone responsive to the last said operation of said relays.

a. telephone system comprising a calling line, multiple jacks therefor, a cord circuit having its answering end connected to one of said jacks, an operators telephone a reverting test relay, means for energizing said relay and connecting it to the answering terminal of the cord, a test relay connected to the calling terminal of the cord, means 7 whereby when the calling terminal is applied to another of said jacks in testing said line said test relay is energized and the reverting test relay deenergized, and circuit connections controlled through normal contacts of the reverting test relay and alternate contacts of the test relay for applying a test tone to said operators telephone.

5. A telephone system comprising telephone lines, multiple jacks therefor, a cord circuit, an 'operators telephone, a reverting test relay operated each time a call is answered, a test relay operated each time a busy called line is tested, ineans'whereby when a calling line is testedasacalled line the reverting test relay is deenergized, and a test tone connected to the operators tele-- phone responsive to such deenergization of the reverting test relay and a testing energizationof the test relay. i

6. A telephone system comprising a telephone line, multiple jacks therefor, a cord circuit, an operators telephone, a high resistance reverting test relay, means for gizing said relay and connecting it to the answering terminal of the cord in answering a call from said line, a test relay connected to the calling terminal of the cord, means for energizing said test relay when testing said calling line as a called line, a low resistance path including the winding of said test relay for shunting said reverting test relay to cause its deenergization responsive to said test, and a test tone applied to said operators telephone responsive to said energization of-the test relay and deenergizatmn of the reverting test relay. 7

7. A telephone system comprising a telephone line, multiple acks therefor, cord circuit provided with a pair of two-conductor terminals, an operators telephone adapted to be automatically connected to and disconnected from said cord circuit, a revertive tone test'relay, manual means for connecting one terminal of said cord circuit to said telephone line whereby said operators telephone and said revertive tone test relay are connected to said cord circuit, and means responsive to the applica ion of the other of said terminals to one of said multiple jacks for causing said relay to apply a test tone to said operators telephone.

A telephone system comprising a telephone line, multiple jacks therefor, a link circuit providedwith a revertive tone test relay, meansresponsive to the connection of the answering terminal of said link circuit to one of said jacks for energizing said relay, means whereby when the calling terminal of said link circuit is applied to another of said multiple jacks said relay is deenergized and operates to connect a-test tone to said operators telephone. 7

9. A telephone system including a calling telephone line provided with multiple jacks, a link circuit provided with ter ls, a revertive tone test relay for said circuit, automatic means responsive to the connection of one of said terminals to one of said jacks for energizing said relay, manual means for testing said line as a calledline by applying the other of said terminals to another of said jacks whereby said relay is deenergized to connect a test tone to said operators telephone.

10. A telephone system comprising a telephone line, multiple jacks therefor, a cord circuit, a pair of relays for the cord circuit, an operators telephone, means controlled by the operator when connecting her telephone in answering a call from said line. for energizing one of said relays, means responsive to a test of said line forde'e'nergizing said re ay and for energizing the second of said relays, and a test tone connected to said operators telephone responsive to the last said operation of said relaysi 11. A telephone system comprising telephone lines, multiple aclis therefor, a cord circuit, an operators telephone, a. revertive test relayoperated whena call is answered, a test relay operated when a busy called line is tested, means whereby when a calling line is tested as a called line the revertive test relay is de'elnergized, and a test tone connected to the operators telephone responsive to suclrdeenergization of said revertive test relay and a testingenergization of the test relay.

A telephone system comprising a telephone line, multiple jacks therefor, a cord circuit provided with a pair of two-com ductor terminals, an operators telephone,a

'evertive tone test circuit having normally open and a normally'closed contact, means nsive to the connection of one of said ie to said line for opening the normally closed contact, and means'responsive to a test by the other of said terminals of one of said multiple jacks for closing the normally open contact and for causing the said first means to return to normal whereby the test tone is operatively connected to said operators telephone, N

13. A telephone system comprising a tele phone line, multiple jacks therefor, .a cord circuit provided with a pair of terminals, an operatofls telephone associated with said cord circuit, a revertive tone test circuit provided with a normally open and a normally closed contact, means responsive to the connection of one or said terminals to one of said multiple jacks for opening the normally closed contact, and means responsive to a test by the o her or said terminals of another of said jacks for causing; the said normally open contacts to be closed and the said normally closed contacts to be returned to normal whereby a tone test is connected to said operators telephone.

let. A telephone system including a telephone line provided with multiple jacks, a link circuit provided with a pair of terminals, an operators telephone, a revertive tone test relay for said link circuit, means responsive to a connection of one or" said terminals to one 01' said jacks "for energizing said relay, means responsive to a connection of the other otsaid terminals to another of said jacks for deenergizing said relay, and a busy tone generator for applying a tone to said operators telephone responsive to said deenergization of said relay.

15. A telephone system includingsubscribers telephone lines, a plurality of link circuits for interconnecting said lines, an operators telephone common to said link circuits, a pair of relays associated with said operators telephone, a tone test de vice, a circuit for one of said relays adapted to be closed when the answering terminal of one of said link circuits is connected to a calling: one of said lines, a circuit for the other of said relays adapted to be closed when the calling terminal of said link circuit is connected to another terminal of said line, and contacts controlled by said relays for connecting said tone test device to said operators telephone.

16. A telephone system including telephone lines, a plurality of link circuits for interconnecting said lines, an operators telephone common to said link circuits, a pair of relays associated with said operators telephone, a tone generator, and means controlled by said relays for connecting said tone generator to said operators telephone when the answering terminal of one of said link circuits is connected to one of said lines and the calling terminal or" said link circuit is used to test the said line.

17. A telephone system including a subscribers telephone line, a plurality of operators link circuits, operators telephone and a plurality of relays common to said link circuits, a tone test device, means for connecting one terminal of one of said link circuits to said line, and means controlled by said relays for operatively connecting said tone test device to said operators telephone when the other terminal of said link circuit is used to test said line as a called line.

18. A telephone system including telephone lines, a plurality of link circuits for interconnecting said lines, an operators telephone and a pair of relays common to said link circuits, a tone test device, and means controlled by said relays for operatively connecting said tone test device to said operators telephone when the called line tested is also the calling line.

19. A telephone system including a poly station subscribers telephone line, an oper ators link circuit provided with only four relays for use in extending a call from said telephone line, an operators telephone, contacts controlled by two of said relays for automatically connecting and disconnecting said link circuit and said operators telephone, a tone test device, and means inclividual to said operators telephone for use in operatively connecting said tone test device to said operators telephone when the operator tests a multiple jack of said telephone line as the called line, said means including a relay normally connected to said operators telephone.

:20. A telephone system including telephone lines, a plurality of link circuits for interconnecting said lines, each of said link 0' ,cuits being provided with only four relays, an operators telephone, mechanism ineluding part of said relays for automatically connectingand disconnecting said operators telephone and said link circuits, a tone test device, and means common to said link circuits and individual to said operators telephone for operatively connecting said tone test de vice to said operators telephone when the called line tested is also the calling line, said means including a relay normally connected to said operators telephone.

21. In a telephone system, the combination of a multi-party line having a plurality of jacks, multiple conductors connecting said jacks, supervisory signals associated with said conductors, reverting testing means, controlling means therefor and a shunt of said controlling means maintained closed during the operation of the reverting testing means, said shunt including one of said multiple conductors.

22. In a telephone system, the combination of a multiparty telephone line having a plurality of terminals, a cord circuit, supervisory signals in said cord circuit, means for connecting the cord to the terminals, reverting testing means associated with said cord circuit, controlling means for said reverting testing means and a shunt 01?; said controlling means controlled through the terminals of the multi-party line, maintained closed during the sending of the reverting busy test signals.

23. In a telephone system, the combination of a multi-party telephone line terminating in multiple jacks, a cord circuit including talking strands and means for connecting said strands to telephone jacks, supervisory signals associated With said cord,

reverting testing apparatus associated Withthe cord circuit, controlling means therefor, and a shunt for said controlling means, including a portion of one of the talking strands of the cord circuit.

Signed by me at Chicago, county of Cook, and State of Illinois, in the presence of two M. R. RooHFoRD.

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