US1537721A - Automatic telephone system - Google Patents

Description

I May 12, 1925.

J. W|CKS AUTOMATIC TELEPHONE SYSTEM Filed Aug. 28. 1922 Wm Q Q Qm QW Patented May 12, 1925.

1 U N! TED .ZS'T P A ENT i O E 'JOI-IN W-IGKS, F OHIGAGO; ILLINOIS, ASSIGNOR' T0 AUTOMATIC ELECTRIC COMPAN Y,

"0F GHICAGO, ILLINOIS, A- 'CORPORATION OF ILLINOIS.

AUTOMATIC; TELEPHONE. SYSTEM.

Application .filed August- 28, 1922.

To all whom it may concern:

Be it known that'I, JOHN'l/VICKS, a citizen of the United States of America, and a resident of Chicago, Cook County, and State 5 of Illinois, have invented certain; new and useful Improvements in Automatic Telephone Systems,of which the following is a specification.

Thepresent invention relates in general to automatic telephone systems, but more particularly to automatic systems for working in conjunction withmanual systems, and the principal object of the invention is to provide meanswhereby a standard type. of 18 automatic connector switch maybe used to test and connect with ordinary manual subscribers lines and make such lines busy when connected with.

.VVhen a vmanual multi-oflice system is changed to automatic.operation, .the manual ofiices are, usually cut over one at a time; thus, during the transition period, some offices are working automatically and some manually. In the exchanges Working manually, selector and connector switches are installed so that incoming. calls from the automatic exchanges to lines in the manual exchanges may be completed automatically. Local calls in the .manual exchanges are completed by the. operators in the usual manner. v

It is well known that .in.manualsystems busy lines are protected by the application of a negative battery. connection to their test conductors while inmost automatic systems busy lines are protected by the application offia positive or ground potential to their test conductors.

4 for the connectors in the. officeswhich are not yet changedtof full automatic operation, but in which incoming calls are completed automatically, to be able to testvfortest p0 -v tentials which are employed .in manualfsysl5 ployed in. automatic systems. Not only is this necessary, but .it is also very desirable after the manual office is changed to full automatic operation,-to use thesesame connector switches with .no change whatsoever for :testing for the testpotentials employed in I automatic systems. 1 It is, therefore,the object of the present inventionto provide translatwith the connector; switches toenable these calling subscribers, It follows, therefore, that.1t 1s .ne,cessary.-

tems instead-of thefpotentials thatare em--- ing relay equipment that may be associated Serial Nm;.584,760.

switches to operate under the conditions described, that-is, first. in. conjunction with amanual system and themwithan auto matic'system, and which will require no change-when the cut over is made except on the disconnection of the translating relays.

There are other objects of the invention, not above mentioned, which will be described inthe following detailed description.

.Referringnow to, thedrawing, the trunk line in, the lower left-hand. portion thereof comprising conductors- 10- 12, accessibleto automatic selector switches in amanual oflice. This trunk line terminates in anautomatic connector switch H.

The connector switch H istofthe usual Str-owger vertical and rotary type and has access to manuallineswin the-exchange, one of these being that of the substation A.

-Associated with the connector-H is the 75 equipment M. The equipmentM consists of the relays. 70 and 71 and is used for testing for the guarding potentialsused in manual systems. This equipment is associated with the connector H through the: medium of the jacks 56 and 57, and 67 and 68. When the exchange is changed. tofull automatic operation, the equipment M is disconnected and the femalejacks 67 and 68: are jumpered together. 7

Associated with the line of the substation A-is the ordinary line equipment comprising a line relay 81 and a cut-ofl'relayq80. The .line of the-substation A; terminates at the exchange in the jack J-and its Vmul-- tiples,:as is the-.usual practice.

To complete connections requested by the A operators are provided with cordcircuits, such as the cord, circuit 0. The cord circuit 0: is of well-known construction, being of the-type whichhas-come into extensive usein manual systems throughout thecountry.

Having briefly described the apparatus shown in thedrawing, .its i operation will now 100 be explained in-detail. :Forthis purpose,- "it inclusive, is

i will be assumed that Tthesubscriber atsubstation A- desires toextend a connection .to

a subscriber in his own exchange.

erator;upon-perceiving the lighted line sig nal, will insert the plug of an idle cord circuit, the cord circuit 0 for example, into the jack J. When the plug P is inserted in the jack J, a circuit is completed for cut-off relay 80 over the sleeve of the jack J in series with the supervisory lamp L. The relay 80 is energized over this circuit and disconnects the line relay 81, which deenergizes,

opening the circuit of the linelamp. Due tothe fact that the receiver is removed at substation A, the supervisory relay 100 in the cord circuit is energized and a shunt is placed around the supervisory lamp L to prevent it from lighting over the previously traced circuit. The operator will now throw her listening key K and request the number desired by the calling party.- Upon ascertaining that a subscriber in the same exchange is desired, the A operator will opcrate her order-wire key extending to the B operators position in the same exchange. The B operator will assign a trunk line and extend the connection to the desired subscriber in the usual manner. The subsequent operations including the control of the supervision when the connection is made and finally disconnected need not be considered here, as it follows well-known manual prac tice.

Attention is directed to the fact that when the plug P of the cord circuit O is inserted into the jack J, a negative battery potential is placed upon the sleeve of the jack in order to busy the line of the calling subscriber. This test potential besides extending to sleeves of multiple jacks, extends to multiply connected test contacts in the banks of connector switches which have access to the line of the substation A. It will thus be seen that while busy, the line of the substation A is rendered inaccessible to connector switches such as H by the application of a negative battery potential'to the test con'ductor..

Should the subscriber at substation A have requested a connection with a subscriber in an automatic oflice, the operator would proceed in a manner similar to that above described, the difference in this case being that the operator would operate the order wire key extending to the automatic ofiice desired and give the number to the B operator thereat. The B operator would then proceed to set up the connectionautomatically in the usual manner.

' We will now consider the operation of the connector H when it attempts to connect with the line of the substation A while the said line is busy. Assuming that the con nector switch H has been seized in the usual manner by a calling subscriber in an automatic exchange through the medium of selector switches, the line relay 16 will be energized. Relay 16, upon operating, at its armature 27 closes a circuit for the slow acting relay 17. The latter relay operates to prepare the impulsing circuits ofthe connector H at armature 30, and at armature 29 places ground upon the release trunk conductor 11. The latter operation serves to establish a holding circuit for the preceding switches in the ofice in which the connector H is located.

When the calling device at the calling substation is operated in accordance with the next digit of the desired number, a series of interruptions is produced in the circuit of the line relay 16, which deenergizes a'plurality of times in response thereto. Upon the first deenergization of the line relay, an impulse of current is sent over a circuit extending from ground by way of armature 27 and its back contact, armature 30 and its front contact, off normal springs 32 and 31, through the winding of the slow acting relay 18, and through the winding of the vertical magnet 51to battery. The above is the circuit over which the first impulse is transmitted to the vertical magnet. Upon the first vertical step of the switch, the off normal springs are shifted and the remaining vertical magnet impulses trc verse a new circuit, which is similar to the one previously traced, except that it includes the off normal springs 32 and'33 and armature 3 1 and its front contact on the slow acting relay 18, which is now energized. The vertical magnet 51 operates to raise the switch shaft carrying the switch wipers 60-62, inclusive, step by step until the said wipers are placed opposite the level of bank contacts in which is located the contact set associated with the line of the substation A. The slow acting relay 18 is energized in series with the vertical magnet, and maintains its armature attra'cted throughout the impulse series, and at the termination thereof deenergizes to transfer the operating circuit to the rotary magnet 53. r

In response to the next and final operation of the calling device at the calling substation, another series of interruptions is produced in the circuit of the line relay 16. This relay retracts its armature a corresponding number of times in response thereto. At each retraction of its armature 27,

an impulse is sent to the rotary magnet 53 over a circuit which may be traced as follows: Ground by way of armature 27 and its back contact, armature 30 and its front contact, oif normal springs 32 and 33, armature 34: and its back contact, back contact and armature 39, armature 47 audits back contact, and through the winding of magnet 53 to battery. Magnet 53 operates to rotate the wipers of the switch step by step until the said wipers are brought into engagement with the bank contact set associated with the line of the called substation A, which, as shown in the drawings, are the bank contacts 6 1-66, inclusive. Upon the first rotary step of the switch, the rotary ofi normal spring 49 is caused to engage its working contact, thereby preparing certain circuits, as will be seen later. The slow acting relay 21 is energized in multiple with the rotary magnet, and operates at its armature 41 to connect the lead 69 to the test relay 20, and at armature 42 to short circuit the contact springs comprising armature 39 and its back contact in order to preserve the continuity ofthe rotary magnet circuit in the case the test relay 20 should become energized on account of the switch wipers being rotated over bank contact sets associated with busy lines.

As the line of the substation A is busy at the present time, there will be a battery potential upon the test contact 65. As soon as the switch wipers are brought into engagement with the bank contact set comprising bank contacts 64t66, inclusive, the relay 71 in the equipment M is energized. Upon operating, relay 71 at armature 74 opens the circuit of the windings of relay 70, and at the front contact of this armature connects ground to the conductor 69. A circuit is therefore completed for the test relay 20, which energizes and operates at armature 38 to prepare a point in its locking circuit, this being closed immediately upon the deenergization of the slow acting relay 21. Further results of the energization of relay 20 are that at armature 39 a point in the rotary magnet circuit is opened, and at armature 40 a lead from the usy signalling machine is connected to the conductor 12. By the latter operation, an audible signal is given to the calling subscriber in order to inform him that the desired line is busy.

It will now be assumed that the line of the substation A is idle when the wipers of the connector H are brought into engagement with the bank contacts 6 166, inclusive. Under these conditions, there will be a ground potential upon the test contact 65 and the relay 71 in the equipment M will remain deenergized. Then, upon the deenergization of the slow acting relay 21, a circuit is completed extending from ground upon release trunk conductor 11 by way of armature 38 and its back contact, through the lower winding of relay 22, back contact and armature 11, conductor 69, rotary off normal spring 19 and its working contact, switch jack 56, shelf pack 67, armature 74 and its back contact, through the windings of relay to battery. Due to the high resistance of the lower winding of relay 70, only this relay is operatively energized over this circuit. Upon operating, relay 70, at armature 72 places a battery potential upon the test contact 65 in order to busy the line of the substation A, and at armature 73 short circuits its lower high resistance winding, so that the relay 22 in the connector H may be operated. The application of the battery potential to the test contact 65 causes the cut off relay in the subscribers line equipment to be energized to disconnect the line of the substation A from its normal battery and ground connections.

In the connector H, relay 22, upon operating, establishes a locking circuit for itself at armature 15, at armature 48 connects direct ground to the winding'of relay 7 0, at armature 16 opens a point in the circuit of the test relay 20, at armature 47 opens the rotary magnet circuit, and at armatures 43 and 50 completes the signalling circuit. Ringing current from the generator Gen is now intermittently projected out on the line of the substation A until an answer is obtained.

When the called subscriber answers, ring out off relay 19 in the connector H is energized. Upon operating, relay 19 establishes a locking circuit for itself at armature 36, at armatures 35 and 37 opens the ringing circuit and at the front contacts of these armatures finally completes the talking connection. talking current to the called substation A and is energized over the called line loop. Upon operating, relay 15 at armatures .25 and 26 reverses the connections of the line relay 16 with regard to the trunk conductors 10 and 12, thereby reversing the direction of thebattery flow over these conductors for supervisory or metering purposes.

When the conversation is completed, the calling subscriber will replace his receiver upon the switch-hook. As a result of this operation, the line relay 16 deenergizes, thereby opening the circuit of the slow acting relay 17. Upon the deenergization of the latter relay, ground is removed from the release trunk conductor 11, and the release magnet 52 is energized. The deenergization of relay 17 also opens the locking circuits of relays 19 and 22, which deenergize, restoring certain circuits to normal. The deenergization of relay 22 also opens the circuit of relay 70 in the equipment M, which deenergizes also. The release magnet 52 operates to restore the connector H to normal. The disconnection of ground from the release trunk conductor 11 brings about the release of the preceding selector switches in the exchange in which the connector H is located. The release of the automatic switches in the exchange in which the call originated, and in intervening exchanges through which the call may have passed, takes place in the usual manner.

Before closing, particular attention is called to the fact that the circuits and wiring of the connector H may be used absolutely without change after the manual exchange is cut over to full automatic operation. All that is necessary is to disconnect the translating equipment M and to jumper together the female jacks 67 and 68, which,

The back bridge relay 15 supplies as is well known, are located on the shelf on which the connector is mounted. Thus, no change is necessary in the connector H. WVith this equipment disconnected, the operation of the connector H is similar to that already described, except that no relays such as relays and 71 are necessary, as the regular testing potentials used in automatic systems are now employed when the exchange operates automatically. That is, there will be a ground potential upon the test contact of a busy line and a battery potential upon the test contact of an idle line.

, Y The features of the invention having been described, what is considered to be new and desired to have protected by Letters Patent will be pointed out in the appended claims.

WVhat is claimed is i 1. In a telephone system, an automatic connector switch, a telephone line having line and test terminals in said switch, a manual jack associated with said line, means for connecting with said line by way of said jack, means for making saidline busy by a negative battery connection to the sleeve of said jack whereby a negative potential is placed on said test terminal, means for operating said connector into engagement with the terminals of said line, means in said connector normally operative responsive to a negative potential on said terminal to connect with said line, a relay group associated with said connector, and circuit connections controlled by said relay group for preventing such connection when a negative battery connection exists on said test terminal.

2. In a telephone system, an automatic connector switch, a telephone line having line and test terminals in said switch, a manual jack associated with said line, a normally grounded test conductor connected to said test terminal, means for operating said connector into engagement with the terminals of said line, means in said connector normally operative responsive to a ground potential upon said test terminal to prevent connection with said line, a relay group associated with said connector, and means con trolled by said relay group for causing such connection responsive to a ground potential upon said test terminal.

3. In a telephone system, an automatic connector switch, a telephone line having line and test terminals in said switch, a test conductor for said line normally connected to the positive pole of battery, means for making said line busy by connecting the negative pole of battery to said test conductor whereby a negative potential is placed upon the said test terminal, means for operatingsaid connector into engagement with said line and test terminals, means in said connector responsive to negative potential on-said test terminal to connect with said line or responsive toa positive potential upon said test terminal to prevent connection with said line, andtranslating relays associated with said connector for changing said postive potential to a negative potential and said negative potential to a positive potential when said connector engages the terminals of said line.

4:. In a telephone system, a subscribers line, a cord circuit and a connector for connecting with said line, means in said cord circuit for placing a certain potential on the test terminals of said line, a test relay in said connector responsive to a different potential, and translating means individual to said connector for enabling said test relay to respond to the particular potential placed on said test terminal by said cord circuit.

5. In a telephone system, a subscribers line having manual and automatic test terminals multiplied together, a cord circuit having testing means responsive to a battery potential on said test terminals, aconnector switch having a test relay responsive to a ground potential, and means responsive to a battery potential on said test terminal when said connector attempts to connect with said line to supply a ground potential to said test relay to operate the same.

6. In a telephone system, a subscribers line having both manual and automatic terminals including test terminals, manual apparatus for connecting with said line, said apparatus including busy testing means responsive to a particular potential on said test terminals and'busying means for placing such potential on said test terminals, an automatic connector switch for connecting with said line having a test wiper for engaging a test terminal of said line, said connector having testing means responsive to a different potential and busying means for placing such different potential on a test terminal, and translating relays intervening between said connector and the test wiper thereof so that when said connector is operated in an attempt to connect with said line the connector will refuse to complete the connection if the line is busy due to a manual call and will make the line busy to said manual apparatus if the line is idle.

7 In a connector switch, a test wiper, a test conductor, means in said connector automatically responsive when the same is operated to connect with an idle line to connect one pole of the battery to said test conductor, and a relay inserted between the said test conductor and test wiper and responsive to such connection of the said test conductor and battery to connect the other pole of the battery to said test wiper.

8. In a connector switch, a test wiper, a test relay having one terminal connected to one pole of the battery, a busy subscribers line having a test contact connected to the same pole of the battery, and a relay inserted between said test wiper and test relay and responsive to the engagement of said test contact by said test wiper to connect the other pole of the battery to the other terminal of said test relay to energize the same.

9. In a connector switch a test wiper, a test conductor, means in said connector automatically responsive when the same is operated to connect with an idle line to connect one pole of the battery to said test conductor, a relay inserted between the said test conductor and test wiper and responsive to such connection of the said test conductor and battery to connect the other pole of the battery to said test wiper, said relay being outside the switch, and means including a pair of switch jacks whereby sald relay is connected in the switch circuit as set forth.

10. In a connector switch, a test wiper, a test relay having one terminal connected to one pole of the battery, a busy subscribers line having a test contact connected to the same pole of the battery, a relay inserted between said test wiper and test relay and responsive to the engagement of said test contact by said test wiper to connect the other pole of the battery to the other terminal of said test relay to energize the same, said relay being outside the said switch, and means including a pair of switch jacks for connecting said relay in the switch circuit as set forth. 1

In witness whereof, I hereunto subscribe my name this 25th day of August, A. 1)., 1922.

JOHN WICKS.

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