US2200593A

US2200593A - Telephone system

Info

Publication number: US2200593A
Application number: US221700A
Authority: US
Inventors: Crocker Thomas Frederick
Original assignee: Associated Electric Laboratories Inc
Current assignee: Associated Electric Laboratories Inc
Priority date: 1938-07-28
Filing date: 1938-07-28
Publication date: 1940-05-14
Anticipated expiration: 1957-05-14

Description

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ATTORNEYS.

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T. F. CROCKER TELEPHONE SYSTEM Filed July 28, 1938 1l Sheets-Sheet 4 INVENTOR. THOMAS F'. CROCKER ATTORNEYS.

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TELEPHONE SYSTEM Filed July 28, 193e May 14, 1940.

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c1335 c1336 @301 c1354F (RAA1151 @A1161 f A1142 RA1153 INVENTOR. THOMAS F. CROCKER A TTORNEY Patented May 14, 1940 ST'iES ,acosta PATENT @FCE TELEPHONE SYSTEM Application July 28, 1938, Serial No. 221,700

85 Claims.

The present invention relates to telephone systems and has for one of its objects the provision of improved apparatus for rendering and supervising toll services in such systems.

s In a telephone system adapted to handle toll traic, an exchange is provided which includes a toll board comprising a number of groups of operators positions and at which the various groups of combined line and recording or C. L. R. and toll lines terminate. Usually the toll board comprises a group of C. L. R. operators positions, a group of toll operators positions and a group of point-to-point operators positions, these groups of operators positions being adapted to handle the respective types of toll services to be rendered. A local switch train and a toll switch .train are provided in the exchange, each being accessible to each operators position at the toll board. In order to supervise and coordinate the work of the operators at the various operators positions at the toll board and to advise the operators in regard to the services to be rendered, a plurality of auxiliary operators positions are associated with the toll board. These auxiliary operators positions usually comprise a chief operators position, a group of supervisory operators positions, a group of rate and directory operators positions and a group of toll service observing operators positions. These auxiliary operators positions must also be coordinated with respect to each other in order to insure that prompt and eiiicient toll services are rendered at the toll board. In order to accomplish these ends, certain of the auxiliary operators positions have access to other of the auxiliary operators positions, to the local and toll switch trains in the exchange and to the various C. L. R. and toll lines terminating at the toll board, in addition to access to each of the operators positions at the toll board. Also, signal arrangements are provided at the toll board and at the auxiliary operators positions in order further to coordinate the work of the operators at the operators positions at the toll board and the operators at the auxiliary operators positions.

It is an object of the present invention to provide, in a telephone system or" the character noted including a toll board and a plurality of auxiliary operators positions, improved apparatus for supervising and coordinating the work of the operators at the operators positions at the toll board in an eiiicient manner which comprises a minimum amount of equipment.

Another object of the invention is to provide, in a telephone system of the character noted and including at least two auxiliary operators positions, an improved arrangement for selectively establishing a monitoring connection and a twoway communication connection between the two operators positions.

Another object of the invention is to provide, in a telephone system of the type described, a switch having access to a plurality of groups of lines, an operators position provided with apparatus successively operative to perform successive control functions to cause the switch to select a line in a particular group of lines, and an improved arrangement for indicating to an operator at the operators position when the apparatus may be effectively operated to perform the successive control functions.

It is another object of the invention to provide, in a telephone system, a switchboard comprising a plurality of operators switchboard positions and an arrangement for assigning calls to the operators switchboard positions in a predetermined order to be answered, another operators position, and an improved arrangement for indicating to an operator at the other operators position a predetermined time interval delay in answering a call.

It is another object of the invention to provide, in a telephone system, a plurality of operators positions, a distributor for assigning calls to be answered by particular idle ones of the operators positions in a predetermined order, and an arrangement controlled when all of the operators positions are busy for assigning calls to be answered by any one of the operators positions. 35

A further object of the invention is to provide, in a telephone system, a plurality of operators positions, and an improved distributor for assigning calls to the operators positions to be answered which is preselective and fully directive in character.

It is a further object of the invention to provide, in a telephone system, a plurality of operators positions, an arrangement for assigning incoming calls to be answered to idle ones of the operators positions in a predetermined order, apparatus at each operators position operative to initiate an outgoing call therefrom, and an arrangement controlled by the operation of the apparatus at each operators position for preventing incoming calls from being assigned to Ythe operators position.

It is a further object oi the invention to provide, in a telephone system, a switchboard including a plurality of operators switchboard 55 positions, an arrangement operative to select idle ones of the operators switchboard positions in a predetermined order and to assign an incoming call to a selected operators switchboard position, an arrangement for routing a call from the operators switchboard position over an outgoing line, another operators position, and arrangements controlled by the selection of a particular operators switchboard position, by the assignment of a call on a particular incoming line thereto, and by the routing of the call over a particular outgoing line for transmitting corresponding signals to the other operators position.

It is a further object of the invention to provide, in a telephone system, a switchboard including an operators switchboard position adapted to route a call therethrough on a particular incoming line over a particular outgoing line, and another operators position provided with improved apparatus for selectively monitoring a connection including the particular operators switchboard position, a connection including the particular incoming line and a connection including the particular outgoing line.

The features of the present invention are illustrated as being incorporated in a telephone system including an exchange provided with a toll board having groups of C. L. R. and toll lines terminating thereat, and a plurality of auxiliary operators positions associated with the toll board and with each other in such a manner that the operators at the operators positions at the toll board may be adequately advised and supervised in order to insure that prompt and efficient toll services are rendered. The toll board includes a group of C` L. R. operators positions, a group of toll operators positions and a group of pointto-point operators positions, a position distributor for assigning incoming C. L. R. calls to idle ones of the C. L. R. operators positions in a predetermined order and a position distributor for assigning incoming toll calls to idle ones of the toll operators positions in a predetermined order. The auxiliary operators positions associated with the toll board comprise a chief operators position, a group of supervisory operators positions, a group of rate and directory operators positions and a group of toll service observing operators positions.

In accordance with one feature of the invention, one of the supervisory operators positions is provided with a line extending thereto over which a call is adapted to be routed. The chief operators position comprises a telephone instrument including a receiver and a transmitter, first and second repeaters being associated with the chief operators position, means for connecting the transmitter to the first repeater, means for selectively connecting the first and second repeaters to the line extending to the supervisory operators position and automatic means controlled by the last-mentioned means for connecting the receiver to the first repeater when the rst repeater is connected to the line, thereby to cornplete a two-way communication connection between the chief operators position and the line, and for connecting the receiver to the second repeater when the second repeater is connected to the line, thereby toi complete a monitoring connection between the chief operators position and the line.

In accordance with another feature of the invention, the telephone system includes an exchange having a plurality of groups of lines associated therewith and extending to dilerent distant exchanges and a switch having access to the lines. Control apparatus is associated with the switch and operative in response to a first control function to perform an intermediate operation which consumes an interval of time and operative in response to at least one additional control function subsequent to the performance of the intermediate operation for causing the switch to select a line in a particular one of the groups of lines. The chief operators position is provided with a signal and apparatus for performing the control functions to which the control apparatus is responsive. An arrangement is associated with the switch and the chief' operettors position for controlling the operation of the signal at the chief operators position during the interval of time the control apparatus is performing the intermediate operation.

In accordance with another feature of the invention, a switchboard is provided which comprises a plurality of operators switchboard positions and has a plurality of lines associated therewith and extending to a distant exchange. A position distributor is associated with the switchboard and is operative to assign a call on one of the lines to an idle one of the operators switchboard positions to be answered. A timer and a signal are associated with the chief operators position; and an arrangement is provided which is controlled by the presence of a call on one of the lines when all of the operators switchboard positions are busy for causing operation of the timer, the timer being effective after the operation thereof for a predetermined time interval to cause operation of the signal at the chief operators position.

In accordance with a further feature of thc invention, the telephone system includes a plurality of rate and directory operators positions.

a plurality of trunk lines individually extending l' to the operators positions, an auxiliary trunk line commonly associated with the operators positions and to which each operators position has access, a switch having access to the trunk lines and operative to seize one of the trunk lines, and a distributor associated with the rate and directory operators position for causing the switch to seize idle ones of the first-mentioned trunk lines in a predetermined order. Also an arrangement is provided which is controlled when all of the operators positions are busy for causing the switch to seize the auxiliary trunk line. In accordance with a further feature of the invention, the distributor associated with the rate and directory operators positions is operative to assign one of the first-mentioned trunk lines extending to an idle one of the operators positions to be seized by the switch operative in response to the seizure of the assigned trunk line by the switch to assign another one of the iirst-mentioned trunk lines extending to an idle one of the operators positions to be seized by the switch. In accordance with a further feature of the invention, a trunk line individually associated with each rate and directory operators position extends to a second switch, and each operators position is provided with means operative to seize the trunk line individually associated therewith. Also. an arrangement is provided which is controlled when the trunk line individually associated with a particular operators position is seized for rendering busy the one of the trunk lines individually extending to the particular operators position.

In accordance with a further feature of the invention, the service observing operators position is associated with the toll board, and an arrangement is provided which is controlled by the operation of the distributor to select a particular operators switchboard position for transmitting to the service observing operators position a signal characteristic to the particular operators switchboard position. Also an arrangement is provided which is controlled by the operation of the distributor to assign a call on a particular one of the lines to the selected particular operators switchboard position for transmitting to the service observing operators position a signal characteristic to the particular line.

In accordance with a further feature of the invention, the lines associated with the switchboard are divided into a group of incoming lines and a group of outgoing lines, and a switch is provided which is operative to route a call between a line in the inco-ming group and a line in the outgoing group, each operators switchboard position being provided with apparatus for controlling the operation of the switch. A signal characteristic to a particular operators switchboard position is transmitted to the toll service observing operators position when the particular operators position is selected by the distributor; a signal characteristic to a particular incoming line having a call thereon is transmitted to the toll service observing operators position when the particular` incoming line is assigned to the particular operators switchboard position; and a signal characteristic to a particular outgoing line over which the call is to be routed is transmitted to the toll service observing operators position after the switch seizes the particular outgoing line. In accordance with a further feature of the invention, equipment is provided at the service observing operators position for selectively monitoring a connection including the particular operators switchboard position, a connection including the particular incoming line and a connection including the particular outgoing line.

Further features of the invention pertain to the particular arrangement of the circuit elements whereby the above-outlined and additional operating features are attained. v

The novel features believed to be characteristic of the invention are set forth in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings in which Figure 1 illustrates the general arrangement of a telephone system embodying the present invention; Figs. 2 to l1, inclusive, illustrate the details of a system having incorporated therein the features of the invention as briefly outlined above; and Fig. 12 illustrates the inode of combining Figs. 2 to 11, inclusive, of the drawings to form a unified system.

DEsoRIrTroN or THE APPARATUS INCORPORATED IN THE TELEPHONE SYsTEM Referring now more particularly to Fig. 1 of the drawings, the telephone system there illustrated comprises a local automatic exchange |25 and two distant automatic exchanges |05 and |06. The local exchange |25 serves a number of local subscriber substations including the subscriber substation indicated at C and associated with a subscriber line H3 extending to the local exchange. Similarly, the distant exchanges |05 and |06 each `serve a number of local subscriber substations including the subscriber substation indicated at A and associated with the subscriber line extending to the distant exchange |05 and the subscriber substation indicated at B associated with the subscriber line I 2 extending to the distant exchange |05. The distant exchanges |05 and |06 are respectively connected to the local exchange |25 by iirst and second groups of two-way toll lines respectively including the to-ll lines indicated at C'Hli and C'||5. Each end of each of the toll lines terminates in a toll line circuit individual thereto, the toll line circuits terminating the ends of the toll lines C'Hll and C'HE at the local exchange |25 being indicated in the group of toll line circuits H0.

The local exchange |25 includes a local switch train |01 having access to each of the local subscriber lines and which preferably comprises a plurality of groups of selector and connector switches of the Strowger type arranged in the usual manner. The local switch train |07 may be controlled by an impulsing apparatus disposed at each subscriber substation in order to set up the various connections between the local subscriber lines in the usual manner. Similarly, the distant exchanges |05 and |05 are provided with local switch trains which may be controlled by impulsing apparatus disposed at the local subscriber substations in order to set up the various connections between the local subscriber lines in the usual manner. Also the local exchange |25 includes a toll switch train which preferably comprises a plurality of groups of selector and connector switches of the Strowger type arranged in the usual manner, and which is utilized in a manner more fully described subsequently in setting up the various toll connections. Similarly, the distant exchanges and |05 are provided with toll switch trains which are utilized in setting up the various toll connections.

An automatic toll board |00 is arranged in the local exchange |25 and comprises a group of C. L. R. operators positions, a group of point-topoint operators positions and a group of toll operators positions, each operators position having access to both the local and the toll switch trains |07 and |03, respectively. Associated with the toll board |00 is a group of C. L. R. lines accessible to the local switch train I0?, one of the C. L. R. lines being indicated at C'Ho and provided with a C. L. R. line circuit |09. Position distributor and, common equipment |03 is associated with the C. L. R. linecircuits and the C. L. R. operators positions in order to assign incoming C. L. R. calls tothe C. L. R. operators positions in a predetermined order. Position distributor and common equipment '|05 is associated with the toll line circuits and the toll operators positions in order to assign incoming toll calls to the toll operators positions in a predetermined order. The toll switch train |05 has access to the local switch train |01 and to the toll line circuits in order to enable an operator at a point-to-point operators position to render point-to-point service and to enable an operator at a to-ll operators position to render inwardl and through service in a manner more fully described subsequently.

Associated with the toll board |00, the local switch train |01 and the tolll switch train |08 is a plurality of auxiliary operators positions including a chief operators position, a number of lsupervisory operators positions, a number of 'rate and directory operators positions, and a nurnber of toll service observing operators positions. In the system illustrated, the chief operators position is indicated at one of the supervisory operators positions is indicated at |02; one of the rate and directory operators positions is indicated at |03; and one of the toll service observing operators positions is indicated at |04. The chief operators position |0| has access to and is accessible to the local switch train |02 by way of a trunk line C1242, has access by way of the trunk line C|241 to the toll switch train |08 and is accessible by Way of a trunk line C|252 to the toll switch train|08. The chief operators position |0| has access to the supervisory operators position |02 by way of a trunk line C|330 and has access to the rate and directory operators position |03 by way of a trunk line C|26.. Furthermore, the chief operators position |l| has access to each operators position at the toll board |00 by way of a trunk line individual thereto, access being had to the first toll operators position at the toll board by way of the trunk line C|258. Finally the position distributor and common equipment '|04 is associated, by Way of the trunk line C|253, with the chief operators position |0| for a purpose more fully described subsequently. The supervisory operators position |02 is accessible to the toll switch train |08 by way of the trunk line C|259. The rate and directory operators position |03 has access to the local switch train |01 by way of a trunk line C|29|, is accessible to the toll switch train |08 by way of a trunk line C|2| individual thereto and an auxiliary trunk line C|2'|0 commonly associated with each rate and directory operators position. The toll service observing operators position |04 is associated with the position distributor and common equipment '|03 and with the position distributor and common equipment '|04 by way of the trunk line C|23| and C|232, respectively, for a purpose more fully described subsequently. Also the toll service observing oper'ators position 04 is associated with a group busy apparatus '|05 by way of a trunk line C|222, while the group busy apparatus '|05 is associated With the toll line circuits ||0 of a particular group of toll lines by way of a trunk line C12| for a purpose more fully described subsequently. Furtherniore, the toll service observing operators position |00 has access to each operators position at the toll board |00 by way of a trunk line individual thereto, access to the rst C. L. R. operators position at the toll boa-rd being had by way of the trunk line C|230, and access to the rst toll operators position at the toll board being had by way of the trunk line C|22|. Moreover, the toll service observing operators position |04 has access to each C. L. R. and each toll line circuit, access to one of the C. L. R. line circuits being had by way of the trunk line C 22B, and access to one of the toll line circuits being had by Way of the trunk line C|2|'|. Finally, the toll service observing operators position |00 has access to each rate and! directory operators position and access to each auxiliary trunk line associated with the rate and directory operators positions, access being had to the rate and directory operators position |03 by way of the trunk line CIZ l0, and access being had to the auxiliary trunk lin@ C|2'l0 associated with the rate and directory operators positions by Way of the trunk line C|308.

Preferably, the toll board |00, the position distributor and common equipment 103 and the position distributor and common equipment 104, associated therewith, are of the construction and arrangement of that described and claimed in the copending application of Thomas F. Crocker, Serial No. 142,558, led May 14, 1937 now' Patent No. 2,167,710, issued Aug. l, 1939. Briefly, the toll board |00, as best shown in Fig. 7, comprises a rst group of operators positions which are utilized as toll operators positions and a second group of operators positions which may be utilized, either as C. L. R. operators positions or as point-to-point operators positions, each of the operators positions of the second group being capable of being converted from one type of operators position to the other merely by operating a key thereat. Accordingly the toll board |00 comprises a plural of toll operators positions, a plurality of C. L. R. operators positions and a plurality of point-to-point operators positions. In the system illustrated, the rst C. L. R. operators position is indicatedy at |0| and the first toll operators position is indicated at "102. The position distributor and common equipment '10?. is so connected and arranged that it selects the C. L. R. operators positions in a predetermined order and assigns an incoming C. L. R. call to a selected C. L. R. operators position. Each C. L. R. operator-s position is provided with a linklistening key which is operable to one position to cause the position distributor and common equipment 103 to select the corresponding C. L R. operators position in the course of operation thereof and operable to another position after the position distributor and common equipment '|03 assigns an incoming C. L. R. call thereto. The position distributor and common equipment '|03 is preselective and fully directive in that it selects an idle C. L. R. operators position having the link-listening key thereat occupying the one position, and subsequently assigns automatically a call on one of the C. L. R. lines thereto in response to the creation of a calling condition on the one C. L. R. line. After the link-listening key at the one C. L. R. operators position is operated to the other position, the position distributor and common equipment 103 operates automatically to select another idle C. L. R. operators position having the link-listening key thereat operated to the one position. Also, each C. L. R. operators position is provided with an answer key which is operated t0 a predetermined position in order to answer a call on the one C. L. R. line assigned thereto and a ringing key which is Operated t0 a predetermined position in order to cause ringing current to be projected over an outgoing toll line over which a call is to be routed. Finally, each C. L. R. operators position is provided with a telephone instrument and an impulsing apparatus thereat in order to control the operations of the local and the toll switch trains |0'| and |08, respectively.

Similarly, each toll operators position is provided with a link-listening key which is operable to one position to cause the position distributor and common equipment '|00 to select the corresponding toll operator-s position in the course of operation thereof, and operable to another posi.- tion after the position distributor and common equipment |04 assigns an incoming toll call thereto. The position distributor and common equipment '|04 is preselective and fully directive in that it selects an idle toll operators position having the link-listening key thereat occupying the one position, and subsequently assigns automatically a call on one of the toll lines thereto in response -on the one toll line assigned thereto and a ringing key which is operated to a predetermined position in order to cause ringing current to be projected over an outgoing toll line, over which a call is to be routed. Finally, each toll operators position is provided with a telephone instrument and an impulsing apparatus thereat in order to control the operations of the local and toll switch trains |01 and |08, respectively. Group busy apparatus 105 is associated with the toll line circuits of the group of toll lines extending to the distant exchange and is operable to transmit a signal to the toll service observing operator's position 00 when all of the lines in the group extending to the distant exchange |05 'are busy.

The chief operators position |0 l, as best shown in Figs. 3, 4 and the portion of Fig. 6 to the left of the dashed line, comprises a primary telephone instrument including a transmitter 330 and a receiver 33|, a secondary telephone instrument including a transmitter 350 and a receiver 349, and an impulsing apparatus 325, the secondary telephone instrument being adapted to be connected by way of the

plugs

334 and 338 associated with the

jacks

342 and 346, respectively, across the respectlve terminals of the primary telephone instrument. Associated with the primary telephone instrument are a iirst repeater 305 and a second repeater 310. A trunk line C|230 and a monitoring plug 300 are provided at the chief operators position I0| and an arrangement including a switch 300 is provided for controlling the association of the

repeaters

305 and 310 with the trunk line Cl230 and the monitoring plug 300. A control relay R350 is provided for selectively connecting the receiver 33| of the primary telephone instrument to the

repeaters

305 and 310. Two control relays R3|5 and R320 are associated with the iir'pulsing apparatus 325 for the purpose of completing a bridge path around at least a portion of the repeater 305, and for interrupting the connection of the receiver 33| to the repeater 305 when the impulsing apparatus 325 is operated, thereby respectively to establish a low impedance impulsing circuit between the impulsing apparatus 325 and the trunk line Cl339, and to prevent clicks in the receiver 33|. The switch 380 is provided with a normal position, a right-hand or ring position and a left-hand or talk position. When the switch 330 occupies its normal position, the repeater 3l@ is connected to the monitoring plug 300 and the repeater 305 is connected to the trunk line (2H-35; when the switch 380 occupies its 'ring position, a source of ringing current is connected to the monitoring plug 300 and the trunk line M239; and when the switch 380 occupies its talk position, the monitoring plug 300 is connected to the repeater 305 and the trunk line (H239 is connected to the repeater 305.

The chief operators position |0| has access to and is accessible to the local switch train |01 by way of the trunk line C |202 and a switch 400 associated therewith. The switch 400 has a normal position, a right-hand or talk position and a left-hand or hold position. When the switch 400 is operated to its talk position, the trunk line C|239 is connected to the trunk line Cl242, and when the switch 400 is operated to its hold position a bridge is connected to the trunk line C|242, thereby to retain the local switch train |01 in operated position. A ring-up relay R460 is associated with the trunk line C|242 and is adapted to illuminate a lamp L402 at the chief operators position in order to indicate to an operator thereat a calling condition of the trunk line Cl242. Associated with the switch 000 and the ring-up relay R460 is a plurality of control relays R442, R645 and R050. These control relays are so connected and arranged that an auxiliary bridge is connected to the trunk line Cl2t2 when the switch 400 is operated from its talk position or its hold position, thereby to prevent the release of the local switch train |01, these relays further interrupting the auxiliary bridge after a predetermined time interval in the event the switch 400 is operated to its normal position, thereby to release the local switch train |01. Further, these control relays control the disconnection of the ring-up relay R400 from the trunk line C|242 and, consequently, the illumination of the lamp L, Finally, these control relays control a charging circuit for the lring-up relay R460 which is provided for the purpose of preventing false operation of the ring-up relay R450 by the switching surges ci current projected over the trunk.l line C|242 incident to the release oi the local switch train |01.

The `chief operators position |0| has access to the toll switch train |08 by way of the trunk line Ci241 and a switch 421 associated therewith. The switch 021 has a normal position, a righthand or talk position and a left-hand orv hold position. When the switch 421 is operated to its talk position, the trunk line C1239 is connected to the trunk line Cl 241 and, when the switch 421 is operated to its hold position, two control relays R414 and R015 are operated. The control relay R415 controls the release of the toll switch train |08 and the operation of `a signal at the toll board |00. Also, an arrangement including a control relay R358 and a lamp L300 is provided for the purpose or indicating to an operator at the chief operators position I0| the time interval during which a selector switch in the toll switch train is hunting for a trunk line extending to a connector switch having access to the desired toll line.

The chief operators position |0| is accessible to the toll switch train |00 by way of the trunk; line C|252 and a' switch M3 associated therewith. The switch H3 has a normal position, a righthand or talk position and a left-hand or hold position. When the switch H3 occupies its talk position, the trunk line C1230 is connected to the trunk line C9252, and when the switch H3 occupies its hold position the operation or a control relay R400 is controlled in order to retain the toll switch train |03 in operated position. A control relay R412 is associated with the trunk line C|252 for the purpose of operating a signal lamp- L401 when a calling condition is created on the trunk line Cl252. Also, a control relay R468 is provided for the purpose of extinguishing the lamp L461, the operation of the last-mentioned control relay being under the joint control of the control relays R464 and R012.

The chief operators position |0| also embodies signaling apparatus 080 associated with the toll board |00. More particularly, the signaling apparatus 480 is associated with the position distributor and common equipment 100 at the toll board and is so connected and arranged that an indication is given to an operator at the chief operators position when a toll call in the inward group of toll trunks at the toll board has a predetermined delayed answering time. More specifically. the signaling apparatus 53|) comprises a lamp LMS, a plurality of control relays Rlltli, R482, Rllll, R488 and R496 and a trunk line Clt associated with apparatus in the position distributor and common equipment- "ru The arrangement is such that operations of these control relays are initiated in the event that all of the toll operators positions are busy and there is no toll operatorsI position to which an incoming toll call may be assigned by the position distributor and common equipment 781i. These control relays constitute a timer and, after operating a predetermined time interval, cause the lamp Lt to be illuminated intermittently.

The monitoring` plug 300 is associated with rst, second and third groups of jacks, the rst group of jacks being connected to trunk lines extending to the respective supervisory operators positions, the second group of jacks being connected to trunk lines extending to the respective operators positions at the toll board |00 and the third group of jacks being connected to trunk lines extending to the respective rate and directory operators positions. In the arrangement illustrated, the jack E05 included in the first group is connected by way of a trunk line Cllil to the supervisory operators position |013.; the jacl; 5|@ included in the second group is ccnnected to a. trunk line C|258 extending to the rst toll operators position '|02 at the toll board HBO; and the jack @l5 is connected to a trunk line Cll extending to the rst rate and directory operators position |03. When the monitoring plug 300 is inserted into the jack E505, a monitoring connection is automatically established from the chief operators position |05 to the supervisory operators position E02, and this connection may be automatically converted into a two-way communication connection therebetween by operating the switch 380 to its talk position. When the monitoring plug 300 is' inserted into the jack Gl, a monitoring connection is automatically established from the chief operators position l QI to the rst toll operators position if?? at the toll board |00, and this connection may be automatically converted into a two-way communica-- tion connection therebetween by operating the switch 3&0 to its talk position. When the monitoring plug 300 isI inserted into the jack Gi, a monitoring connection is automatically established from the chief operators position l0! to the iirst rate and directory operators position |05, and this connection may be automatically converted into a two-way communication connection therebetween by operating the switch 380 to its talk position.

The jack Gli) has a lamp M529 individually associated therewith which is controlled jointly by the busy or idle condition of the rst toll operators position '|02 at the toll board and a master switch 620 at the chief operators position |0|, the master switch 52! being connected and arranged in the circuits for illuminating the lamp 1.629 and the other lamps individually associated with the other jacks corresponding to the jack 6|0 and extending to the other operators positions at the toll board.

Two lamps L63!! and LGSS are individually associated with the jack SI5, the lamp T4534 being connected and arranged to be illuminated when the rst rate and directory operators position |03 answers a call on the rst auxiliary trunk line CZl'li, and the lamp being connected and arranged to be illuminated when the rst rate and directory operators position |03 is rendered busy by operating a switch |060 thereat. The supervisory operators position I 02, as best shown in Fig. 6 to the right of the dashed line, comprises' a telephone instrument including a transmitter 'll and a receiver 679, a repeater 600, a signal lamp L5M, an alarm 8530, and an arrangement comprising two plugs 058 and G62 and two jacks GGG and 610 for connecting the telephone instrument to the repeater 690. The supervisory operators position |02 is accessible by way of the trunk line C|339 to the chief operators position Hl! and accessible by way of the trunk line C|26l to the toll switch train |08. The supervisory operators position |02 also includes a plurality of control relays RG/itl, R644, R552 and Ri and a ring-up relay R650 for con-- trolling the illumination of the lamp L649, for controlling the operation of the alarm 680 and for controlling the marking of the trunk line CIZGQ as busy to the toll switch train |08.

Associated with the rate and directory operators positions, as best shown in Figs. 9 to l1, inclusive, is a position distributor H70 which comprises a plurality of control relays RIHU, REUS, Rll'i, RI 00. This position distributor |70 is connected afmA arranged to assign three rate and directory operators positions in a predetermined order to the use of the operators at the toll board I. position it comprises a telephone instrument including a transmitter |0|3 and a receiver |0| 4, an impulsing apparatus lBl, a repeater 9H! and a plurality of control switches |020, |030, |040 and |050. The iirst rate and directory operators position Yl0?. is accessible by way of the trunk line C|27| individual thereto to the toll switch train |08 and accessible by way of the trunk line CIZ'LL commonly associated with each rate and directory operators position to the toll switch train m8. An arrangement including two plugs will and ltl and two jacks |00| and |904 is provided for connecting the telephone instrument at rate and directory operators position |53 to the repeater SID. The switch |040 is operable between two positions to selectively connect the rate and directory operators position l 53 to the trunk line C|2`|| and the auxiliary trunk line Cl2'i0. A plurality of control relays Ptsif'l, R940 and R935 are associated with the rate and directory operators position |03, and so connected and arranged that a zip-zip tone is produced in the receiver |0|4 when the toll switch train $013 seizes the trunk line C|2`|| assigned to be seized by the distributor H70. Also, a control relay R is associated with the rate and directory operators position E03 in order to control the marking of this position as busy to the toll switch train MES under the control of the telephone instrument thercat. The switch |060 has a normal position, right-hand and left-hand positions. When the switch |060 occupies a right-hand position a signal is operated at the toll board |00, and when the switch |060 occupies a left-hand position the rate and directory operators position |03 is rendered busy to the toll switch train |00 and a signal is operated at the chief operators position |0|. Further a control relay R950 is associated with the rate and directory operators position |03 which is connected The iirst rate and directory operators 3 Ail) and arranged to control a signal at the chiel operators position |9| to control the operations of the lamps L|939 and L|931 at the rate and directory operators position |93, and to control the marking of the trunk line Ci|21| as busy to the toll switch train |98 when the rate and directory operators position |93 is connected to the auxiliary trunk line C|219.

Associated with the auxiliary trunk line C|219 are a plurality of control relays R969, R965, R915,

-R985 and R995, the control relays R995, R915 and R985 also being respectively associated with the first, second'and third rate and directory operators positions. The control relay R995 is connected and arranged to control the operation of the control relay R969, which latter relay controls the operations of the signals at each rate and directory operators position when the toll switch train |98 seizes the auxiliary trunk line C |219. The control relay R965 is connected and arranged to be controlled at the first rate and directory operators position |93 and is effective to control the operation of the control relay R959. in a similar manner, the control relays R915 and R985 are connected and arranged to be controlled at the second and third rate and directory operators positions, respectively.

The service observing operators position |94, as best shown in Figs. 2, 5 and 8, comprises a receiver set 851 including two

receivers

858 and 859 individually associated with two plugs 894 and 891, respectively, and two signal current amplifiers 859 and 869 which are respectively associated with two pairs of

jacks

819, 882, and 816, 898. The amplifier 859 is associated with a switch 829 connected to a monitoring plug 89| and the amplifier 859 is associated with the switch 839 having a normal position and right-hand and left-hand positions. When the switch 839 occupies a right-hand position, the amplifier 869 is connected to a monitoring plug 895, and when the switch 839 occupies a left-hand position the amplifier 859 is connected to a monitoring plug 8|9. The toll service observing operators position |94 is also provided with a plurality of jacks individually associated with the toll line circuits, a plurality of jacks individually associated with the toll operators positions, a plurality of jacks individually associated with the C. L. R. line circuits, a plurality of jacks individually associated with the C. L. R. operators positions, a plurality of jacks individually associated with the rate and directory op-erators positions, and a plurality of jacks individually associated with the auxiliary trunk lines commonly associated with the rate and directory operators positions. In the arrangement illustrated, the jack 519 is individually associated with one ofthe toll line circuits |9; the jack 515 is individually associated with the first toll operators position 192; the jack 589 is individually associated with one of the C. L. R. line circuits |99; the jack 585 is individually associated with the iirst C. L. R. operators position 19|; the jack 599 is individually associated with the iirst rate and directory operators position |93; 4and the jack 525 is individually associated with the first auxiliary trunk line C|219 commonly associated with the rate and directory operators positions. A group of control relays is individually associated with the jacks associated with the toll line circuits, and a group of control relays is individually associated with the jacks associated with the C. L. R. line circuits. In the arrangement illustrated, a control relay R555 is associated with the jack 519 and a control relay R565 is associated with the jack 589. Further, a control relay R569 is associated with the position distributor 193 and a control relay R559 is associated with the position distributor 194. A number of lamps L551, 1,558, L551 and L558 are respectively associated with the control relays R555, R559, R555 and R559. The operation of the control relays R559 and R599 are under the control of the position distributors 194 and 193, respectively, and the operation of the control relays R555 and R565 are under the control of one of the toll line circuits |I9 and one of the C. L. R. line circuits |99, respectively. Also, two control relays R529 and R539 arel provided in order to control the operation of the control relays R559 and R555 and two control relays R5|9 and R549 are provided in order to control the operation of the control relays R569 and R555. A control relay R239 is provided which is controlled by the operation of the switch 839, and two control relays R249 and R259 are provided which are controlled by the operation of the ringing keys at the operators positions at the toll board |99. Two control relays R599 and R595 are provided in order to control the operation of a control relay corresponding to the control relay R555. Further the control relays R249 and R259 control the illumination of a supervisory disconnect lamp L29! and a supervisory ringing lamp L292 at the toll service observing operators position |94. The operation of the various control relays are controlled by a plurality of switches 295, 2|9, 2|5, 229 and 225 at the toll service observing operators position |94. By utilizing the equipment at the toll service observing operators position |94, in a manner more fully described subsequently, all of the services rendered by the operators at the various operators positions at the toll board |99 may be monitored. Furthermore, the arrangement of the control relays and the lamps at the toll service observing operators position |94 is such that an operator at the toll service observing operators position |94 is adequately advised as to which operators position at the toll board the service is to be performed at and which C. L. R. and toll lines are involved in the various connections.

Operation of the apparatus at the toll board The toll board |99 comprises a plurality of combined line and recording or C. L. R. operators positions and a position distributor 193 associated therewith for the' purpose of selecting the positions and assigning incoming C. L. R. calls thereto as previously noted. More particularly, the position distributor |93 selects sequentially the C. L. R. operators positions having operated link-listening keys and assigns an incoming C. L. R. call to the selected C. L. R operators position When the position distributor 193 operates to select a particular C. L. R. operators position, it applies ground potential to the control conductor individual to the position and extending to the toll service observing operators position ii. For example, when the position distributor w3 operates to select the rst C. L. R. operators position it, ground potential in the position distributor 'i513 is applied to the control conductor (H235 individual to this position and extending to the toll service observing operators position E04. This application of ground potential to the control conductor CIZSI causes the position lamp L568 at the toll service observing operators position E64 and individual to the lrst C. L. R. operators position 10| to be illuminated under certain operating conditions, in order to assist the operator at this position in observing the service rendered by the operator at the rst C. L. R. operators position 10|, in a manner more Jfully explained subsequently. When the operator at the rst C. L. R. operators position itil answers an incoming C. L. R. call assigned thereto by the position distributor Vit, the link-listening key thereat is returned to its busy position and the position distributor T53 operates automatically to select another C. L. R. operators position to receive the next incoming C. L. R. call. The position distributor SSS also operates at this time to remove ground potential from the control conductor 0323i, thereby to perform, under the operating conditions noted, a function at the service observing operators position Hifi, as is more fully explained subsequently.

The operator at the iirst C. L. R. operators position "mi may seize the toll switch train 08 and dial a series of digits thereinto to cause t to seize an idle toll line in a particular group of toll lines. When the toll switch train its is operated to seize an outgoing toll line, ground potential in the toll switch train is applied to the control conductor of the trunk line. For exampie, when the toll switch train 38 seizes the outgoing toll line C'Hli, ground potential in the toll switch train is applied to the control conductor thereof, which ground potential is conducted by way of the toll line circuit individual to the toll line C7 l@ to the control conductor CH2 l 6 of the trunk line C2il extending to the service observing operators position idd, thereby to cause, under the operating conditions noted, the toll line lamp 1355's' individual to the toll line C'I I4 to be illuminated.

After an outgoing toll line has been seized by the toll switch train l S8, the operator at the rst C. L. R. operators position operates the ringing key at this position, thereby to cause ringing current to be projected over the outgoing toll line and to cause ground potential at this position to be applied to the control conductor Cl229 of the trunk line CIZ individually associated with the first C. L. R. operators position. This application of ground potential to the control conductor C5228 of the trunk line Ci23i! causes, under the operating conditions noted, the ringing supervisory lamp L29? at the toll service observing operators position Hifi to be illuminated. When the toll operator in the distant exchange answers the toll call extending thereto, the operator at the rst C. L. R. operators position '16! operates the ringing key at her position to arrest the application of ringing current to the outgoing toll line extending to the distant exchange. When this ringing key is thus operated, ground potential is removed from the control conductor C|229l of the trunk line CIZSS, thereby to cause, under the operating conditions noted, the ringing supervisory lamp L?i to be extinguished. In

order to release the established connection extending to the distant exchange, the operator at the rst C. L. R. operators position 78 operates a release key at her position, causing ground potential to be applied through a resistor to the control conductor Ci229 of the trunk line CiZIiS, thereby to cause, under the operating conditions noted, the disconnect supervisory lamp L20! at the toll service observing operators position 904 to be illuminated.

The toll board also comprises a plurality oi toll operators positions and a position distributor 'ili associated therewith for the purpose oi selecting the positions and assigning incoming toll calls thereto. More particularly, the position distributor 'H14 selects sequentially the toil operators positions having operated link-listening keys and assigns an incoming toll call to the selected toll operators position. When the position distributor i055 operates to select a particular toll operators position, it applies ground potential to the control conductor individual to the position and extending to the toll service observing operators position |04. For example, when the position distributor 'fl operates to select the first toll operators position 792, ground potential in the position distributor 'iS/i is applied to the control conductor C|232 individual to this position and extending to the toll service observing operators position Ili. This application of ground potential to the control conductor CITY-32 causes the position lamp 1.558 at the toll service observing operators position teli and individual to the first toll operators position '102 to be illuminated, under certain operating conditions, in order to assist the operator at this position in observing the service rendered by the operator at the first toll operators position 7&2, in a Inanner more fully explained subsequently. When the operator at the rst toll operators position TD2 answers an incoming toll call assigned thereto by the position distributor 7M, the link-listening key thereat is returned to its busy position and the position distributor 184 operates automatically to select another toll operators position to receive the next incoming toll call. The position distributo-r li also operates at this time to remove ground potential from the control conductor CIZSZ, thereby to perform, under the operating conditions noted, a function at the service observing operators position i343, as is more fully explained subsequently.

The operator at the first toll operators position E92 may seize the toll switch train ltt and dial a series of digits thereinto to cause the toll switch to seize an idle toll line in a particular group of toll lines, thereby to cause, under the operating conditions noted, the toll line lamp individual thereto at the toll service observing operators position 84 to be illuminated as previously explained.

After an outgoing toll line has been seized by the toll switch train ID3, the operator at the iirst toll operators position operates the ringing key at this position, thereby to cause ringing current to be projected over the outgoing toll line and to cause ground potential at this position to be applied to the control conductor C5229 oi' the trunk line CHEZ! individually associated with the iirst toll operators position. This application of ground potential to the control conductor C5228 of the trunk line C|22I causes, under the operating conditions noted, the ringing supervisory lamp L2 G2 at the toll service observing operators position |04 to be illuminated. When the toll operator in the distant exchange answers the toll call extending thereto, the operator at the first toll operators position 102 operates the ringing key at her position to arrest the application of ringing current to the outgoing toll line extending to the distant exchange. When this ringing key is thus operated, ground potential is removed from the control conductor CI22 of the trunk line CIZ? I, thereby to cause, under the operating conditions noted, the ringing supervisory lamp L2Il2 to be extinguished. In order to release the established connection extending to the distant exchange, the operator at the rst toll operators position 102 operates a release key at her position, causing ground potential to be applied through a resistor to the control conductor C1220 of the trunk line CI22I, thereby to cause, under the operating conditions noted, the disconnect supervisory lamp L20I at the toll service observing operators position H54 to be illuminated.

An arrangement is provided at the toll board Illll in order to indicate to the toll service observing operators position IEM when all of the toll lines in a particular group at the toll board are busy. For example, an arrangement is provided for indicating when all of the outgoing toll lines extending to the distant exchange M15 are busy, which comprises a group busy apparatus 105 individually associated by way of the trunk line C12I with the line circuits of the group of outgoing trunk lines extending to the distant exchange H35, a control conductor CIEM and a lamp L519 located at the toll service observing operators position IM. When all of the outgoing toll lines extending from the toll board lili! to the distant exchange |05 are busy, the group busy apparatus 105 individually associated therewith by way of the trunk line 012| is operated, to apply ground potential to the control conductor CI222, thereby to cause the lamp L519 to be illuminated.

The position distributor 1&4 is so connected and arranged that ground potential is applied therein to the control conductor CI253 extending to the chief operators -position lill when the position distributor may not operate to assign an incoming toll call to one of the toll operators positions due to the fact that none of the linklistening keys at the toll operators positions are operated to cause the position distributor tooperate to select the corresponding toll operators position. The application of ground potential to the control conductor CI2525 causes the lamp L498 at the chief operators position IBI to flash after a time interval of approximately four seconds, thereby to indicate to the operator at the chief operators position that an incoming toll call has had a delayed answering time of approximately four seconds.

Each of theC. L. R. operators positions and each of the toll operators positions has access to the toll switch train |08. More specically, the first C. L. R. operators position 10| has access to the toll switch train lll by way of a group of trunk lines including the trunk lines C1i8 and Cll, and the iirst toll operators position 102 has access to the toll switch train by way of a group of trunk lines including the trunk line C120. Also, the toll switch train I is accessible to the chief operators position i0! by way of the trunk line C3241. The toll switch train il has access byway of the trunk line CI252 to the chief operators position IUI, access by way of the trunk line CIZBS to the supervisory operators position I 32, access by way of the trunk line C l 21I to the rate and directory operators position H13, and access by way of the first auxiliary trunk line Ci21 to each of the rate and directory operators positions. The toll switch train m8 also has access by way of a group of trunk lines including the trunk line C119 to the local switch train 01, and access by way of the trunk lines C111 and C123 to the toll line circuits individual to the toll lines C1il and Cll, respectively, included in groups of toll lines extending to the distant exchanges H35 and it, respectively. The local switch train w1 is accessible by way of the trunk line CI2l2 to the chief operators position I@ I, and accessible by way of the trunk line Ci 251i to the rate and directory operators position HB3. Also, the local switch train is accessible to the subscribers station C by way of the subscriber line 1I3. The local switch train |01 has access by way of the subscriber line 'I i3 to the subscribers substation C, and access by way of the trunk line CIEM! to the chief operators position I Si. Further, the local switch train m1 has access by way of a group of C. L. R. lines including the C. L. R. line C1Ili, the line circuits individual thereto, and the trunk line C122 to the position distributor 183. Each incoming toll line, including the toll lines CTM and C1l5, has access by way of the toll line circuits individual thereto and the trunk line C123 to the position distributor 104.

In order to extend a call initiated at the substation A associated with the distant exchange 05 to the substation B associated with the distant exchange It and routed by way of the toll board la, the subscriber at the substation A removes the receiver of the telephone instrument thereat from its hook and dials a proper series of digits into the local switch train in the distant exchange IIlE in order to establish a connection to a C. L. R. operators position thereat. The operator at the C. L. R. operators position in the distant exchange H35 answers the call and, after receiving the information concerning the called substation B, dials a proper series of digits into the toll switch train therein in order to cause the toll switch train to seize an idle toll line, such, for example, as the toll line C1l 4 extending to the toll board Ill. The incoming toll call on the toll line C144 is routed by way of the toll line circuit individual thereto, the trunk line 123', and the position distributor 194 to one of the toll operators positions. Assuming that the call is routed to the rst toll operators position 182, the operator at this position answers the call and receives the information concerning the called substation B. The operator at the toll operators position 1&2 then seizes the toll switch train IBS by way of the trunk line C and dials a proper series of digits thereinto to cause the toll switch train to seize the trunk line C123 extending by way of the toll line circuit individual to the toll line C1l5 to the toll linev C'II5. The operator at the first toll operators position 152 then operates the ringing key thereat to project ringing current over the outgoing toll line C1I5, causing the toll call to be answered at the distant exchange IS by a toll operator thereat. The toll operator in the distant exchange H16 then receives the information concerning the called substation B and dials a proper series of digits into the switch train therein to cause the subscriber line 112 to be seized. Ringing current is then projected over the subscriber line 1I2 extending to the substation B. When the subscriber at the substation B answers the call, the toll operator in the distant