US1645662A

US1645662A - Measured-service telephone system

Info

Publication number: US1645662A
Application number: US745334A
Authority: US
Inventors: Rodney G Richardson; John I Bellamy
Original assignee: Automatic Electric Inc
Current assignee: Automatic Electric Inc
Priority date: 1924-10-23
Filing date: 1924-10-23
Publication date: 1927-10-18
Anticipated expiration: 1944-10-18
Also published as: GB241932A

Description

Oct. '18, 1927.

1 1,645,662 R. G. RICHARDSON ET AL MEASURED SERVICE TELEPHONE SYSTEM Filed Oct. 23, 1924 I 3 Sheets-Sheet 1 -hmm Rudrz By E. Emhapdsun and Julmlfiellamy Hug.-

1927' R. G. RICHARDSON\ET AL 1645662 MEASURED SERVICE TELEPHONE SYSTEM Filed Oct. 23, 1924 3 Sheets-Sheet 2 w t; N i

E I Q S Q J\ I? E I fmrEnmPs-- Eudnay E. Fzchardsun End Juhn [.55

Ham

18 1927. Q 1645 662 Oct R. e. RICHARDSON ET AL MEASURED SERVICE TELEPHONE SYSTEM v Filed Oct. 25, 1924 3 Sheets-Sheet :5

Imranlws R E! [11159 B. Euzhardsmn and Jmhn I. E EHETHH Patented is, 19 27. g UNITED sTAT s RODNEY e. menannson, or cinema, AND JOHN i. BELLAMY, or naooxrrEnn, 11.1.

N015, assrcnoas, BY MESNE ASSIGNMENTS, 'ro auroua'rrc ELECTRIC me, or cnrcaeo, rumors, A CORPORATION or DELAWARE.

MEASURED-SERVICE TELEPHONE sYsrEul Application-filed October 1924. Serial No. 748,334.

In other words, the object of the resent invention is to provide a plurality o party line subscribers substations with individual call registers at the exchange selectable upon the initiation of a call and operated subsequently-due to the response of the called A special object is to accomplish the meter selection by means of apparatus 10- cated in the first selector trunk rather than by means of apparatus individual to the party line. Each meter selecting apparatus is thus made common to a group of party 1 lines and each party line has individual to t it' onlythe usual line switch and the meters corresponding to its stations.

Another special object is to provide for the selective operation of all meters associated with a party line over a single conductor extending from the individual line switch to the apparatus in the first selector trunk circuit. Each trunk therefore re- .quires only four conductors, the two line conductors, a holding conductor, and the meter operating conductor.

Other and further features of the inven- 85 tion are more or less subordinate to the above and will be fully apparent from the following description when read in connection with the accompanying drawings which .show by means of the usual circuit diagrams a sufiicient amount of the apparatus in a telephone system embodying the principles of the invention to permit anyone experienced in the art to'app-reciate its merits and its utility.

'The inventive idea involved is capable of receiving a variety. of expressions, one of which, for the. purpose of illustrating the invention, is shown in the drawings, but it is to be'expressly understood that said drawings are employed merely for illustrating the invention as-a whole and not to define the limits thereof, reference being had to the appended claims for this purpose.

Referring now to the drawings,-Fig. 1

shows four subscribers substations A, B, O and D, a line switch LS provided for the extension of a call originating, at any one, 4

of the substations, a trunk circuit TC comprlsin a source of current of positive and one 0 negative polarity and designated by the reference numerals 16 and 17, respect vely, -a stepping switch MSS for the selection and subsequent actuation of the proper meter which is eifected through the operation of the polarized relay 1-90'when the called party answers. This drawing shows also the four meters M M M and M belonging-respectively to the substations A- D, inclusive, but located within the central exchange.

Fig. 2 shows a selector S, a connector C, and the desired subscribers line switch, as well as the substation equipment of that party. The connector has not been shown fullybut to a sufficient extent to comprehend the invention.

Fig. 3 illustrates four multi-contact relays designated by the numerals 501-504, inelusive, and two stepping devices X and Y which co-operate with the equipment shown in Fig. 1 in selecting and energizing the calling partys meter in a manner to be fully described later. The relays 501-504, inclusive, are common to a" relatively small group of lines, but the stepping devices X and Y are common to the entire exchange. The invention having been described gen= erally, we shall proceed now to present .a detailed description of the operation of the apparatus shown. For this purpose it will be assumed that the subscriber at substation D desires to converse with the subscriber at substation E.

0 When the receiver is removed at substation D, line relay energizes over

line conductors

1 and 2, and places ground on -pri- 80," test wiper 92 is connected to the junction of switching relay 70 and ste in ma net at armature82. I pp 0 g Incase the trunk upon which the wipers.

of the line switch are standing is idle, switching relay 70 energizes immediately. Assum-v ingthe trunk to be busy, however, switching relay 70 is short circuited by ground encountered on the busy test contact by test wiper 92 and does not energize, and the wipers are rotated step by step by the buzzer- I like action of stepping magnet '90 which rates through test wi er 92. Vvhen an idl: trunk is reached, wich trunk it will be assumed is the one comprising

conductors

100, 103 and 104, switching relay (0, being 1. no longer short circuit, energizes in series with stepping magnet 90. 90, however, does not energize at this tlme on account of the high resistance of switch- 7 ing relay 70. Switching relay 70, upon energizing, opens a point in the test clrcuit and prepares the holding circuit at armature 72, and at armatures 71 and 74

disconnects line conductors

1 and 2 fromthe winding of line relay and ground, and extends them by way of wipers 91 and 94, bank contacts 95 and 98,

conductors

100 and 104,

armatures

151 and 155 and their resting contacts, and armatures 111 and. 115 to the winding of rela 120 and to ound.

The calling su station has thus been con= nected to the trunk circuit TC, and the meters M M, inclusive, individual to the arty line substations A--.-D, respectively, have also been extended by way of wiper 93 of the line switch;

Relay 120 new energizes over the calling line and closes a locking circuit for itself at armature 121 and thrcugh armature 152 of relay 150, and at armature 122 places ground on release trunk conductor 103, thereby closing the usual holding .circuit for switching relay 70 of the line switch LS before the slow acting line relay 80 has had time to deenergize. Armature 123 of relay 120 prepares a circuit for pick-up relay 110 and armature 124 applies ground to the common start conductor 43 to operate the switch X, Fig. 3, through the interrupter 523.

Accordingly, if it is not already operating the common stepping switch X now starts to operate and advances its wiper 521 in the direction indicated by the arrow. When magnet 520 energizes, ground is connected over armature 522 to one of the conductors 41, 42 or 44, depending upon which of the bank contacts wiper 521 is resting, but wiper 521 is not advanced at this time. When magnet 520 deenergizes the wiper 521 advances by one ste The operation of the switch does not a ect the trunk circuit TC, however, until wiper 521 reaches the pick-up contact 524. New, as soon as magnet 520 energizes again it applies, at armature 522, ground to the common pick-up conductor 44, thereby closing a circuit through oif normal contacts 14 of the meter selecting switch MSS, working contact and armature 123, and the normally closed contact controlled by armature 113 for pick-up relay 110. This relay operates and locks itself ever its arm- Stepping magnetature 113 to ound om armature 152 of rela; 150. T e armatures .111 and 115 change over into their alternate positions and connect both sides of the line to the contacts of the left hand bank of the meter selecting switch MSS; armature 112 prepares a circuit for stop) relay 150; and armature 114 prepares the circult for step ing magnet 125 which will be completed su bsequently over conductor 42 upon the deenergization of magnet 520 of common switch X. It willbe observed that relay 120, though disconnected now from the line conductor, is maintained energized over its own armature 121 to ground on armature 152 of relay 150.

The deenergization'of magnet 520 o f-switch- X, caused through the continuous action of interrupter 523, advances the wi r 521 to contact 525, and, upon the following energization of magnet 520, ground is connected contact 525 to operate the steppinmagnet 125 of the meter selecting switch SS over armature 114 and its working contact. Stepping magnet 125 energizes and advances wipers 10, 11, and 12 on the forward stroke to position them onto the first bank contacts. Armature 13 is operated also and removes relays 130 and 140 from the circuit joining wipers 10 and -11 for a purpose to be explained hereinafter. It will be seen that igh voltage battery of negative polarity is connected now to the upper line conductor 1 from the current source 17, bank contact 63. wiper 11. armature 13 of magnet 125 and its working contact, wiper 10, bank contact 61, Working contact and armature 111 of relay 110, resting contact and armature 151 of relay 150, conduct-er 100, bank contact 95 and wiper 91 of the line switch, and workin contact and armature .71 of the line switch switching relay 70. 1 g It will be remembered that substation D had been assumed to be the calling party. The switch-hook contacts 9 and It are therefore in operated position and ground is connectedto "line conductor 1 from switch-hook contact h, over both windings of the polarized rela P in series, contact 2' of the dial, receiver transmitter T, and switch-hook contact 9*. The polarized relay P responds to a current of positive polarity only and remains therefore inert in the circuit from the current source 17 which is of negative polarity.

Magnet 520 of switch X deenergizes now,

retracting armature 522 and advancing wiper 521 to bank contact 526. Ground is removed from conductor 42 and the stepping magnet 125 of the meter selecting switch MSS deenergizes, thereby inserting at the armature 13 the relays 130 and 140 into the circuit between wipers 10 and 11.

Relay 130 operates, and at armature 131 closes a point in the circuit of stop relay 85 to conductor 42 over armature 522 and bank conductor 41 will not energize stop relay 150 at this time, because relay 140 is energized.

Wiper 521 is resting now on the bank contact in which it is shown in the drawing. Magnet 520 in operating again, attracts its armature 522 as before, and ground is connected to conductor 42. Stepping magnet 125 energizes, advancing-the wipers 10, 11'

and 12 to the second bank contacts-and connecting thereby a high voltage current of positive polarity from the current source 16 over the bank contact 64 to the upper line conductor 1. The polarized relay P energizes now and at armature E removes the shunt from around the resistance 1".

Magnet 520 of switch X deenergizes then and removes ground. from conductor 42 by opening its armature 522, and at the same time advances its wiper 521 to the next bank contact. The stepping magnet 125 consequently deenergizes and restores its contact 13 to normal, thereby connecting the relays 130 and 140 again in the testing circuit. It is apparent that the relays 130 and 140 energize again in the testing circuit, as the shunt,removed around the resistance r by the energized relay P is now located in the opposite line conductor, i. e. conductor 2, whereas the testing takes place over conductor 1. When switch X connects ground to conductor 41, the same conditions as before prevent the stop relay 150 from energizing.

The meter selecting switch MSS will now advance to the third position and connect,

high voltage current of negative polarity from the current source 17 to the lower line conductor 2, but P being of positive polarity, does not operate. When the stepping magnet 125 resumes its normal position in accordance with the operation of switch X,

the relays 130 and 140 are inserted into the test circuit and operate again. Therefore, ground applied to conductor 41 is ineffective.

Switch X now grounds conductor 42 and the Wipers 10, 11 and 12 advance to the fourth bank contacts. Wiper 11 encounters the positive high voltage current source 16, whereupon the polarized relay P energizes I over the lower line conductor 2 and through armature E and its resting contact and calling device contacts [0 andi. Relay P,

upon operating removes the shunt from around resistance 1. Switch X continues its operation, removes ground from conductor 42, and deenergizes thereby the stepping magnet 125. Armature 13 assumesthe position in whlch it is shown in the drawing,

and connects the rela s 130 and 140 in circuit with the 'polarize magnet P and resistance 1". Relay 130 operates in this circuit as before; the relay 140, however, remains mert because of the resistance '9" which had been connected in this circuit by the polarized relay F. Ground is connected to conductor 41 upon the next energization of magnet 520 of switch X, and relay 150 operates from ground on conductor 41, armature 112 and its working contact, working contact and armature 131,,resting contact and armature 141, winding of relay 150 to battery. In operating, this relay locks itself to the grounded release trunk 103 at armature 153.

Armatures

151 and 155 switch the trunk through to the first selector S shown in Fig. 2; armature 152 opens the locking circuit of relays 110 and 120, and armature 154 prepares the circuit of an alarm signal AL, the purpose of which will be explained later. Responsive to the opening of their lockin circuits at armature 152, the relays 110 and 120 deenergize, relay 110 immediately and relay 120 shortly thereafter.

Line relay 210 of the first selector S shown in Fig. 2, now energizes over the calling subscribers loop and closes at armature 211 a circuit for release relay 220. At armature 221 relay 220 places ground on release trunk conductor 103, thereby closing the usual holding circuit for switching relay 1'50 of the trunk circuit TC shown in Fig. 1 before slow acting relay 120 has had time to deenergize. The calling subscriber receives now a signal that he may operate the dial, from ground at the induction coil shownat the lower left corner of Fig. 2, over the lower winding of relay 210, the line loop and back to battery over the upper winding of relay 210.

The calling party has thus been extended to the first selector shown in Fig. 2, and the meter provided for the calling substation and located at the central exchange has'also been determined and will be operated upon the called party answering the call. The calling subscriber, upon receiving the dial tone, may now commence to operate his impulse device.

It has been seen that the line relay 210 of the selector S energized and caused the operation of the release relay 220. Upon energizing, release relay220 opens a point in the circuit of release magnet 280 and prepares a circuit for vertical magnet 260 at armature 222.

When the calling subscriber operates his calling device in accordance with the first resting contact, armature 222 and its working contact, slow rela 230, and vertical magnet 260 to battery; y the operation of vertical magnet 260, the wipers 263-265, inclusive, are raised opposite the desired level of bank contacts. Relay 230 is energized in series with vertical magnet 260 and, being slow acting, retains its armature attracted throu hout the vertical movement. As a result 0% the energization of relay 230, it closes a circuit at armature 231 for stepping rela 240 by way of oil normal contacts 262, whic close upon'the first'vertical step and interrupter contacts 271. Stepping relay 240, upon energizing, closes a locking circuit for itself at armature 241, and at armature 242 prepares a circuit for rotary magnet 270.

At the end of the vertical movement, slow acting relay 230 deenergizes and completes the circuit of rotary magnet 270 at armature 231. Rotary magnet 270, upon energizing, advances the wipers 263-265, inclusive, into engagement with the first set of bank contacts in the desired level, and, near the end of its stroke, opens the circuit of steppin relay 240 at interrupter contacts 271. epping relay 240, upon deenergizing, opens the circuit of rotary magnet 27 0 at armature 242, whereupon rotary magnet 270 deenergizes also and closes its interrupter contacts 271 again. In case the trunk terminating in the firstset of bank contacts is idle, switching relay 250 energizes immediately. Assuming the trunk to be busy, however switching relay 250 is short circuited by the ground potential encountered by test wiper 264 and stepping relay 240 energizes from this same ground potential and closes the circuit of rotary magnet 270 again, whereupon the switch wipers are rotated into engagement with the next set of bank contacts. This alternate operation of stepping relay 240 and rotary magnet 270 continues until an idle trunk is reached, which trunk it will be assumed is the one comprising the conductors which terminate in bank contacts 363-365, inclusive, whereupon switching relay 250, being no longer short circuited, energizes in series with stepping relay 240. Stepping relay 240, however, does not energize at this time on account of the high resistance of switching relay 250. Switching relay 250, upon energizing, opens a point in the test circuit and prepares the holding circuit at armature 252, thereby opening the circuit of release relay 220, and at armatures 251- and 253 disconnects conductors 101 and 102 from the windings of line relay 210, and extends them by way of

wipers

263 and 265, bank contacts 363 and 365, to the windings of line relay 310 of the connector.

Similarly to the operation of the selector the connector C will lift the wipers 340-342, inclusive, up to the desired level and then, in response to the last digit, position them on the desired partys line, which is indicated through the bank contacts 440-442 located in the connector bank. Ringing curcrates.

Armatures

321 and 322 reverse t e current flow in the line and also'in the line relay 310 of the connector 0. As a result of this current reversal, the electroolarized relay 190 of the trunk circuit T Fi 1,-

energizes over its upper winding whic is connected in parallel to resistance 196, and locks itself over its lower winding and its armature 192 to ground at armature 152 of relay 150. The resistance 197 which is thereby short circuited is provided to prevent a premature operation of relay 190 when relay 150 energized and closed its armature 152. Armature 191 short circuits resistance 196 to eliminate unnecessary line resistance during conversation; armature 195 prepares the metering circuit; armature 194 prepares a circuit for the pick-up relay 180; and armature 193 applies ground to the common start conductor 50 to operate the switch Y, Fig. 3, through the interrupter 513.

Accordingly, if it is not alread operating, the common stepping switch now starts to operate and advances its wipers 511 in the direction indicated by the arrow. Switch Y, like the stepping switch X, is of the type which advances the wiper on the back stroke, i. e. u on the deenergization of the magnet 51.0. en magnet 510 energizes, ground is connected over armature 512 and wiper 511 to one of the conductors terminating in the bank contacts, depending on which of the contacts the wiper is resting. The operation of the switch does not aflect the trunk circuit TC, however, until wiper 511 reaches the pick-upcontact 514 or the corresponding second pick-up contact 516. Now, as soon as magnet 510 energizes again 1t applies at armature 512 ground to the common pick-up conductor 49, thereb closing a circuit through armature 194 0 relay 190 and its working contact, and the normally closed contact controlled by armature 183 for pick-up relay 180. This relay op crates and locks itself over its armature 183 to ground on armature 152 of relay 150. Ar mature 181 closes an additional short circuit around resistance 196 to keep this resistance eliminated after the subsequently following deenergization of relay 190; armature 182 opens a point in the circuit of relay 190 extending through resistance 197 to prevent the relay 190 from locking itself over this resistance when its deenergization is effected through the subsequent operation of relay 170. This provision is necessary because of the retaining action caused throu h the shunt around the upper winding 0 relay 190. Relay 190 w1l1 therefore retain its armature for a short period after the circuit of its lower winding is interrupted and would lock itself afterwards over the resistsince 197. This is prevented by armature 182 circuit which will be completed over the wiper 12 of the meter selecting switch MSS which had been positioned on the bank contact 67 upon the initiation of the call at substation D.

Magnet 510 deenergizes now and advances wiper 511 to the second bank contact, that is the contact followin either pick-up contact 514 or 516. It is apparent that this arrangement has been provided merely for convenience, chiefly to reduce the time of switch operation, as neither of the two steppi'ng switches has a normal position. Magnet 510 energizes again and ground is applied over the armature 512 and wiper 511 to the common metering conductor 45 and to the common conductor 531 which terminates in the group metering relay 501.

It is obvious that ground applied to conductor 45 does not produce any operation on account of wiper 12 of the meter selecting switch MSS which is positioned on bank contact 67. Ground on conductor 531, however, causes the energization of group meter ing relay 501. This, and the remain ng group metering relays 502-504, inclusive, are multi-contact relays, that is apparatus which, by energizing, close a plurality of contacts. lays are. known and ma be used, such, for example, as is describe and illustrated in the application of Martin, Serial No. 429,- 547, of Decemberv 9, 1920. According to the size of the relay, or, more particularly, according to the number of contacts operated at a time, such a relay serves a plurality of meters. The urpose of these relays will be apparant rom the following enample. f it is assumed that 100 party lines have to be served and that four substations are on each party line, 400 meters have to be provided for. In this case it will be convenient to use four multi-contact relays each having 100 contacts. These four relays are illustrated with 501-504, inclusive, Relay 501 serves all No. 1 meters, relay 502 all meters No. 2, relay 503 all meters No. 3, and relay 504 all meters No. 4. By following the conductors 35-38, inclusive, it will be seen that they terminate in the corresponding meters M M respectively.- Accordingly, the. remaining contacts shown at the multi-contact relays lead to meters of other lines.

It has been seen that the stepping switch Y applied ground to conductors 45 and 531, causing thereby the operation of the multicontact rela 501, while ground on conductor 45 could not produce any operation be- Various constructions of such rether point in its own locking cause of wiper 12 of the meter selecting switch which is positioned on contact 67. Relay 501 attracts its armature and connects battery to all meters No. 1,- one of which is shown in M, F ig. 1. It is apparent from the drawing that the operation of any one of the meters M-M, inclusive, can be effected over wiper 12 of the metering switch only, which rests on contact 67. No metering takes place,'therefore, until the stepping switch Y reaches the bank contact 515 or the corresponding contact 517. Now, as soon as magnet 510 energizes again, it applies, at armature 512, ground to the common conduetors 48 and 534, thereby closing a circuit for the multi-contact relay 504. This rela operates and connects battery over con uctor 35 to meter M, Fig. 1, and the 1 meter energizes now by way of armature 73 of the line switch switching relay and its working contact, wiper 93 and bank contact 97 of the line switch, conductor 107,

normally closed contact controlled by armature 162 of relay 160, winding of relay 170, armature 184 of relay 180 and its working contact, working contact and armature 195 of relay 190, wiper 12 and bank contact 67 of the meter selecting switch MSS, conductor 48, bank contact 515 or 517 and wiper 511 of the stepping switch Y to ground on armature 512 of the magnet 51). The relay 170 energizes in this circuit and opens at armature 171 the circuit of relay 190. It may be pointed out that the interrupter 513, Fig. 3, delivers a pulse somewhat longer than is required to operate one of the meters shown in Fig. 1, and that the adjustment of the electro-polarized relay 190 is such that its short circuited upper winding imparts suflicient sluggishness to permit this relay to hold up a suflicient length of time to, insure the operation of the meter. In no case, however, will this relay hold up until the end of the pulse delivered by the interrupter, and relay. 1 90 always drops back and opens the metering circuit at armature 195, at the same time opening a fur- (circuit at armature 192. Therefore. rela gizes before end of pulse delivered byinterrupter 513 to prevent reoperation of the meter and at armature 193 disconnects the common start conductor 50 to 'sto .the stepping switch Y; armature 194 isconnects the common pick-up conductor 49; armature 195 opens a oint in the metering circuit and causes t ereby the deenergization of relay 170; armature 192 opens its own locking circuit, and armature 191 opens one shunt from around resistance 196 which however, is maintainedby armature 181 0% relay 180. Relay 180 remains energized over its own armature 183 and its working contact. q

When the conversation is completed the 190 deen'erg on.

, ofi normai contacts 18.

two subscribers replace their receivers. When the receiver is replaced at substation D the circuit of the line rela 310 of the connector C, Fig. 2, is open whereupon the line and release relay of the connector deener ize and the connector is restored to norma position in themsual manner., As soon as ground is removed from release trunk conductor 300 by; the deenergization of the release relay of connector C, theicircuit for switching relay 250 ofthe selector S, switching relay 150 of the trunk circuit TC, and of. the line switch isopened and the said rela s immediately deenergizeu In the selector switching relay 250, upon deenergizing, closes at armature 254 the circuit for the release magnet 280 which inclugles armature 211 of line relay 210 and its resting contact, armature 222 of the reiease relay 220 and its resting contact, and the oil normal contacts 261. n the trunk ciscuit TC, relaye150, upon deenergizing, closes at armature ,:152 the circuit for "the release ma net 126 of the meter selecting switch M S, which includes the armature 113 of relay 110;and its resting contact, and the Relay 180 deenergizes also. 5

It has been seen that the subscriber at substation D, Fig. 1, had been cennected to thedesired partye at substation E, Fig. 2. The re er meterM had been selected upon the initiation of the cali; by means of the trunk circuitTC o eratirirg jointly with the common stepping evice f shown in Fig. 3, and it has also been seen that the operation of the meter took place upon the response of the called part W It is also apparent from the foregoing t at the stepping switches X and Y are provided common to ;a plurality oftrunk circuits. .The selection and operationof meter M provided for substation C shall be described next. For this purpose it will; be assumed that the subscriber at substation C originates a call.

Vihen the receiver is removed at substation, C the line is extended by means of the line sWitch LS to a trunkcircuit which is assumed to; be the'one comprising conductors -98,;inclusive. It will be' observed that the relay P at substation C is polarized such as to respond to a current of negative polarity, and that battery is now connected to this relay b way of relay 120 of the trunk circuit T resting contact and armature 111 of the pick-up relay 110, resting contact and armature 151 of stop. relay 150, conductor 100, bank contact 95 and wiper 91 of the line switch, working contactand armature 71 of the line switch switching relay 70, conductor 1, contacts 9 of the switch-hook transmitter T receiver R, contact i of the impulse device D, both windings of therpolarized relay P in series to ground at contacts h of the switch-hook.

. The current flowing in this circuit, though and repares at armature 123 the -circuit for t e pick-up relay 110, which energizes. when the wipe1g521 of the switch X reaches 70 'mon start conductor 43 in the usual manner-,2

bank contact 52%. Now, in energizing, pick- 75 up relay 110 connects the line conductors and 104 to the left hand bank contacts of the meter selectin :switch MSS as heretofore described in etail. Ground is conmagnet 125 of the meter selecting switch MSS energizes and o'sitions the wipers 10, 11 and 12 onto the rst bank contacts, connecting thereby high voltage current of negative polarity from the current source 17 to the upper line conductor. The polarized relay P of the, substation O operates and at its armature E removes the shunt from around resistance 1". Ma net 125 deenergizes now and at the norma ly closed contact controlled by armature 13 connects the relays 130; and 140 between the testing circuit. Beth relays energize due to the fact that resistance 7- is at *this time located in the circuit of the opposite line conductor 2, whereas the testing takes place'over conducnected now to conductor 42 by switch X and 30 tor 1. Ground on conductor 41 which is connected now by the switch X is therefore ineffective, i. e. stop relay 150 does not energize, and the magnet 125 of the meter selecting switch MSS is operated again on the next energization of magnet 520 of the stepping switch X and mores the wipers 10, 11 and 12 to the second bank contacts. It is apparent from the drawing that high voltage current of positive polarity from the current source. 16 will be connected now to the upper line conductor 1. The polarized relay P does not respond to this current, and upon the deenergization of imagnet 125, the relays 130 and 140 operate. Ground connected to conductor 41 is therefore ineffective again. When magnet 125 energizes for the third time and positions the wipers 1Q; 11 and 12 onto the third bank contacts, it;connects high voltage current of negative polarity to the lower line conductor. The polarizedmelay E of substation C operates removingit its armature E the shunt from around resistancer andconnectin this resistance in series with its own windm The relays 13% and 140 are inserted in t e last mentioned circuit u on the deenergization of magnet 125, and w ile relay 130 energizes,

relay 140 remains inert because of the added resistance of 1' hen ground is connected again to conductor 41 the stop rcla 150 operates as already explained in detail and switches the line conductors through to the selector S shown in Fig. The callingsubline switch LS extends the calling line to the trunk circuit TC, Fig. 1, and relay 120 operates, starting switch X Fig. 3, over start conductor 43. Switch X operates and connects ground to the pick-up conductor 44, causing thereby the operation of the pick-up relay 110 which connects at armatures 1'11 and 115 both line conductors to the left hand bank contacts of the meter selecting switch MSS. Conductor L2 is grounded now by switch X, and magnet 125 of the meter selecting switch MSS operates as usual and connects high voltage current of negative polarity from the current source 17 to the upper line conductor. Relay P which is olarized to respond to current of positive p0 arity only does not energize in this circuit of negative polarity, and, upon the deenergization of magnet 125 the relays 130 and 140 are connected in series with the polarized relay P and operate. Ground is connected now b switch X to stop conductor 41. It is o vious that this ground is ineffective at this time because of armature 141 of relay 140 which is opened. Magnet 125 receives a ground impulse now from switch X and advances the wipers 10, 11 and 12 of the meter selecting switch MSS to the second position, thereby connecting high voltage current of positive polarity from the current source 16 to the upper line conductor 1 and through the shunt around resistance 1, to rela P which is of positive polarity. Belay accordingly, operates removing at its armature E the shunt from around resistance r ,Upon deenergizing, magnet 125 opens its armature 13 and connects thereby over the normally closed contact the relays 130 and 140 in series with both windings of the polarized relay P and resistance 7'. Relay 130 operates in this circuit as usual while relay 140, because of the added resistance 1' remains inactive. Ground which is applied. now to the stop conductor 41 by switch X causes the energization of stop relay 150.

Armatures

151 and 155 extend the line through to the selector S shown in Fig. 2, and armature 152 causes the disconnection of the relays 110 and 120 and of the common switch X, Fig. 3.

If the subscriber at substation A desires a callhis meter M at the central exchange is selected when the meter selecting switch MSS advances its wipers 10, ,11 and 12 to.

the first position. The polarized relay P operates in responseto the high voltage current of negative polarity connected from the current source 17 by way of bank contact 63,

wiper'11, armature 13 of magnet 125 and its working contact, W1 er 10, bank contact 61, working contact an armature 111 of relay 110, resting contact and armature 151, con-' ductor 100, bank contact 95 and wiper 91 of the line switch, working contact and armature 71 of the line switch switching relay 70, upper line conductor 1, the shunt around resistance 7, impulse contacts and contacts 21, both windings of the polarized relay P to ground at contact 12 of the switch hook. In operating relay P removes at armature E the shunt from around resistance 1' The relays 1'30 and 140 are inserted now upon the deenergization of magnet 125 in series with the olarized relay P and resistance T and re ay 130 o erates while the marginal relay 140 remains inert because of resistance W. The circuit for the stop relay 150 is completed over conductor 41 upon the next energization of magnet 520 of stepping switch X, Fig. 3. In energizin relay 150 switches the calling line throug to the selector switch S, Fi- 2, and disconnects the common switch X 1n the usual manner.

It will be understood that means must be provided to prevent false metering in case 7 of a simultaneous call, or in case a subscriber removes the receiver in an attempt to call, while the meter selecting switch MSS is operating to test the line for a party which originated a call previously. No meter is selected in either case and the meter select- 1ng switch advances into its fifth position. This will appear clear if remembered that testing is accomplished by means of the relays 130 and 140, the latter of which is marglnal. Relay 1 10- is prevented from .operatin under normal conditions because of the a ditional resistance connected in the test circuit by the energization of the polarized relay of the calling substation, while relay 130 operates. The circuit for stop relay 150 is thus prepared by the

armatures

131 and 141 and will be completed upon the next energization of magnet 520 of ste ping switch X as has been explained in etail. Upon energizing, stop relay 150 prevents a further advance of the meter selecting switch MSS. Now, if two subscribers call simultaneously, or if an additional party removes the receiver during the operation of the meter selecting switch MSS, it is obvious that the marginal relay 140 energizes in series with relay 130 to ground at the second partys switch hook contact. Stop relay 150 does not operate therefore and the meter selecting switch advances until it reaches the fifth bank contacts. Upon the deenergization of magnet 125, the relays 130 and 140 are connected again in the'test circuit. Resistance 68 which is connected to the fifth contact of the left hand bank of the metering switch MSS takes in this case the place of the substation and is sufiiciently high to prevent the energization of the marginal rela 140, while relay 130 operates as usual in t is circuit which, as can readily be seen from the drawing, includes the lower winding of relay 160, which energizes also. Rela 160 repares a locking circuit for itsel throng its armature 161, and at armature 162 prepares a circuit for relay 170 which will be completed by the operation of

relays

190 and 180 when the called part answers. Resistance 172 is thereby substituted for the meter and relay 170 operates in the same manner as already descrlbed in detail except that it energizes over resistance 172 instead of in circuit with a meter, and causes the restoration of the trunk circuit.

' At armature 163 a circuit is prepared for applied to conductor 41 by switch an alarm signal A over conductor 15. Sto

relay 150 operates now through ron d 1 3, and, in addition to its usual functioni, completes the circuit of the alarm signal A at its armature 154. The oflice attendant may now connect himself to the call by means of jack 19 and determine in the usual manner which of the substations is calling. The meter selecting switch MSS advances to its fifth position and causes the operation of the alarm signal A also in case a calling.

subscriber, attempts to fraudulently influence the metering action by moving his switch hook up and down while the meter selecting switch is operating. *This will be explained now more in detail. .For this purpose it will be assumed that the subscriber at substation A originates a call and attempts to prevent metering by moving, the switch hook. In will be remembered from the detailed description of this case that high voltage current of negative polarity from the current source 17 is connected to the upper line conductor 1 and thence through both windings of the polarized relay P to ground at switch hook contact h Relay P as has been seen, responds to this current and connects the resistance r in series with its own winding. This additional resistance prevents the marginal relay 140, which is subsequently connected between the test circuit, from energizing and causes the circuit to be prepared for sto relay 150. In movin the switch hook, t e subscriber alternate y connects and disconnects the ground connection at switch hook contact 71. If ground is disconnected at the instance of testing, the polarized relay P cannot energize. The relays 130 and 140 are now connected in the testing circuit at i the normally closed contact controlled by armature 13. It is obvious that none of the two relays operate because of switch hook contact h, which is assumed to be open at the moment of testin The stop relay 150 from ener 'zing and is therefore prevent I advances the meter selecting switch MS calling party by causin to its fifth, position and causes the operation of the alarm signal A as in thepreceding case in which it was assumed that two subscribers originate a call simultaneoutsly or but a very short period of time apar 7 It has therefore been seen that the operation of the meter is prevented in the first case in order to avoid false charging, in the second case to signal the attendant in response to a fraudulent attempt to suppress the operation of the meter on the part of the calling party. The attendant, after having investigated the reason for the operation of the alarm may charge the call to the the actuation of the proper meter, whic may be accomplished bymeans of a manually operated switch or any other well known provisions. It is obvious and need not be described specifically, that the actuation of the alarm signal may also be caused b a faulty operation of the trunk circuit. he experience of the attendant must be relied upon to detect the cause for its actuation.

It is apparent from the foregoing that b means of this invention a simple and efii cient circuit arrangement is provided whereby a meter correspondin to any substation on a party line may be se ected for operation so that calls originating on the line will be recorded against the party originating them.

It has also been seen that a false metering,

been shown that an attempt on the part.

of the calling subscriber to avoid the charging of a call is met by simple and effective means in the form of an alarm signal. It may also be said that this last mentioned means renders also a fair observation service and contributes to the efliciency of the exchange, as it permits to educate parties who habitually knock at the switch hook. It-will also be obvious that the principles herein discussed may be embodied in many other organizations widel different from those illustrated, without e'parting from the spirit of the invention, as defined in the following claims.

What is claimed is:

1. In a measured serviceparty line telephone system, party lines, meters at the exchange, one for each party on each line, a meter selecting switch at the exchange common to said lines set in motion responsive to a call from any station on any said line, and electromagnetic means at the station of the line calling for stopping said switch in the correct position to select the meter which corresponds to the calling station.

2. In a measured service party line telephone system, party lines, meters at the exchange, one for each party on each line, a selector switch, an automatic switch for exposition of said switch, and means for stopmatically responsive to a call for selecting ping the switch responsive to the testing of the calling station;

3. In a. measured service party line telephone system, a party line, a'meter at the exchange for each party on the line, a meter selectin switch set in motion responsive to a call rom any station on said line, said switch operating to select each of said meters in turn, means for testing the party line in a different way after each meter is selected, and marginal means at the exchange controlled from the calling station for stopping said switch when the line is tested 1n a particular way.

4. In a measured service party line telephone system, a arty line, a meter at the exchange for eac party on the line, automatic switches at the exchange controlled from any calling station on said line vto extend a connection to a called line, said. switches including a line switch individual to said line'and a first selector, means individual to said first selector operated autothe meter which corresponds to the calling station, and an operating circuit common to said meters extending through said line switch.

5. In a measured service party line telephone system, a group of arty lines, first selectors, automatic switc ing mechanism for extending any party line when calling to an idle first selector, a plurality of meters individual to each line, one for each station, a common connection between said meters also extended to the idle selector b said switch mechanism, and means indivi ual to each first selector responsive to the connection of a calling line with the selector for selecting the particular 'meter individual to the calling line which co, responds to the calling station.

6. In a measured service party line telehone system, a plurality of groups of party ines the stations on said lines, means individual to each group of party lines and responsive only to calls from lines in its own group for selecting the meters which correspond to the calling stations, a source of current, and

means common to all said groups for causing said current to operate the selected meters.

7. In a meter control system, a plurality of meters, a common conductor extending to one terminal of all said meters, individual individual meters at the exchange for a conductors extending to the op site'termlnals of all said meters, a secon set of indivldual conductors, means for connectin said common conductor to any conductor 0 said second set, a battery, means for successively connecting one pole of said battery with the conductors of the first set, and means for successively connecting the other pole of said battery with the corresponding conductors of the other set. i

8. In a meter control system, a pluralit of sets of meters, a conductor common to a l the meters of one set, other similar conductors for the other sets, a conductor commonto the first meters of all sets, other similar conductors common, respectively, to the second, third, etc., meters of all sets, means for connecting one pole of a battery to the conductors of the second series successively, and means for connectin the other pole of the battery to any-de sire conductor of the first series at the time the first pole is connected to any particular conductor of the second series, whereby any particular meter can be actuated.-

9. Ina measured service party line tele-- phone system, a party line, meters at the exchange individual to the stations on said line, automatic switching mechanism responsive to the removal of the receiver at a calling station on said line for extending the line, means also responsive to the removal of the receiver at; said station for selecting the meter corresponding to such station, means for locking the connection independent of the calling station while meter selection is taking place, and means for preventing meter selection from being accom lished if the receiver at the calling station is hung up.

10. In a measured service party line telephone system, a party line, meters at the exchange individual to the stations on said line means at the exchange responsive to the initiation of a call on said line to select the meter corres ending to the calling station and means or preventing the selection 0 any meter if calls are initiated at two stations at the same time.

11. In a measured service party line telephone system, a party line, meters at the exchange individual to the stations on said line, means at the exchange responsive to the initiation of a call on said line to select the meter corresponding to the calling station, and means for preventing the selection of any meter in case a call is initiated at a second station before the meter corresponding to the first calling station has been selected.

12. In a measured service party line telephone system, a party line, meters at the exchange individual to the stations on said line means at the exchange responsive to the initiation of a call on said line to select the meter lcorresponding to the calling station means effective to prevent the selectlonot any meter in ease a non-standard condition occurs on said line during meter selection, and means forgiving analarm to notify the attendent that; a call is being made and no meter has been selected. if

13. In a telephone system, a part line, stations thereon, a separate meter at t e central oflice for each of said stations, a source, of battery potential, and means at the central oilice fortesting said party line substations to select the meter; individual to the calling substation by applyin said source to one side of the line and is en to *the other.

14. In a telephon system, a party line, stations thereon, a separate meter {at the central ofiice for each of said stations,a trunk line, an automatic switch for connectin said zline with said trunk line, a stepping: evice individual to said trunk, and means for ad; vancing said stepping device to test said par-i ty line for the various substations thereon, and to select thereby the meter corresponding to the calling substation and means for; stopping said device in response to its se-' lection of such meter.

15. A plurality of party lines, stations thereon, a separate meter at the central oflice for eaclr of said stations, a trunk terminating in 111621.118 to extend a call from any of said stations, a source of current, and means associated with said trunk for testing any of said party lines for the various substations thereon and 'ior selectin thereby the meter corresponding to the ca g substation by connecting said source to one conductor of the line and then to the other 16. A plurality of party lines, stations thereon, a separate meter at the central oflice for each of said stations, switching means at the central oflice accessible to any (if said party lines, a stepping device asseciated with said switching means, and means for advancing said s'teppin device varying distsnces depending on t e station calling to test a calling one of said plurality of party lines for the various substations thereon and 5 to select thereby the meter corresponding to the calling substation.

17. a telephone system, a part stations thereonfa separate meter at t e central exchange for each of said stations,

line, 1

ter at the central exchange for each of said stations, aplurality: of trunks accessible to said party line progvided for the extension of, calls, a single nietering conductor associated with each of said tranks, a source of meter operating potential, ;and means common to said plurality of trnnks for connecting said source to any one at said meters to the exclusion of the others :over any one of said single metering conductors. 7

19. In a telephone exchange system, "a party line, stations thereon, a separate meter at the central exchange for each of said stations switchi'ng means at the central exchange including a single metering conduetor, and means or simultanedusly applyi battery to only one of said meters associat d with said line and placing ground at the same time upon said single metering conductor to operate thus any one of said meters individufl to said party'line selectively, to the exclusien of the others.

20. In a telephone exchange system, a party line, stations thereon, a separate meter at the central exchange for each of said stations, a combined meeer selecting and station testing switch temporarily associated with said line, positions am said switch corresponding to said meters and stations, respfitive1y,"an alarm signal, an additional position on said meter selecting switch corresponding to said alarm signal, and means to advance said meter selecting switch to said additional position to cause the operation of said alarm signal in case it does not select iany one of the meters of said partyf line.

In witness whereof, we hereunto subscribe our names, this 17th day of October A. D.',' *1924.

RODNEY G. RICHARDSON. JOHN I. BELLAMY. F