US1332222A - Automatic telephone system - Google Patents

Description

A. E. LUNDELLAND G. THOMPSON. AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED APR.13. 191a.

Patented Mar. 2, 1920.

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&' T 1 m A/bvn [.Lunde/l eorye Thompson A. E. LUNDELIZAND a. THOMPSO AUTOMATIC TELEPHONE SYSTEM} a Pa rgantd- Mar. 2, .1920.

APPLICATION FILED APR. I3. I91

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A. E. LUNDELL AND G. THOMPSON;

' AUTOMATIC TELEPHONE SYSTEM.

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Patented Mar. 2, 1920.

7 SHEETS-SHEET 4.

A. E. LUNDELL AND G. THOMPSON.

AUTOMATI C TELEPHONE SYSTEM.

APPLICAIION FILED APR.13.19IH.

Patented Mar. 2, 1920.

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A. E. LUNDELL AND G. THOMPSON.

AUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED APR. I3. I918.

1,332,222. Patented Mar. 2, 1920.

ISHEETS-SHEET 6.

1 venfa /'5.- A/ben L 4074/0. earge 7270/7305 0/7 A. E. LUNDELL AND G. THOMPSON. AUTOMATIC TELEPHONE SYSTEM. APPLICATION HL'En APR. 13. 1918.

1,332,222. Patented Mar. 2, 1920.

7 SHEETSSHEET 7.

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(w/qr Thompson mam) STATES PATENT curios. v

ALBEN E. LUNDELL, or NEW YORK, Am) GEORGE moiurson; 01 110cm VERNON, NEW

YORK, ASSIGFQBS T WESTEBN ELECTRIC COMPANY, INGORIORATED, OF 'NEW YfiRK, N. Y., A CORCFORATION OF NE'W YORK.

AUTOMA'ITC TELEPHONE SYSTEM.

Patented liial.2,1920

Applidation filed April 13, 1918. Serial 1W0. 228,344.

To all whom it may concern:

Be it known thatwe, Annex E. LUNDELLY and Guonon THoMrsox, citizens of the United States, residing at New York, in the county of Bronx, State of New York, and at Mount Vernon, in the county of Westchester, State of New York, respectively, have invented certain new and useful Improvements in Automatic Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone exchange systems and more particularly to telephone exchange systems in which connections are established by'meansof automatic switches under the control of a calling subscriber.

It is the object of this invention to provide an exchange system of large capacity which will utilize a minimum of apparatus and which will operate rapidly and elliciently.

It is more specifically the object of this invention to provide an improved coin collect and metering system to be used in connection with an automatic telephone system.

A feature of the invention isthe utilization of common coin collect and metering apparatus which may be operated to release the calling subscriher s line so that it may be seized as a called line and so that he may initiate a second call in as short. a time as possible after he has taken steps to release the apparatus.

An additional feature is the use of quicknecessary portions of the apparatus of a.

telephone system required to embody the features of the present invention.

1. shows a calling vsubscribefis line,

Fig. A

distributing switch individtogether with a ual to such hue, and the circuits of a selector switch; Fig. 2

shows two quick-acting switches which may be used to associate common controlling apparatus with a selector switch taken for use. Within the dotted rectangle in Fig. 2 is shown metering and coin return apparatus, together with a controllingsequence switch therefor; Fig. 3 shows portions of a register controlling apparatus, together with a special'coin return device. The coin return device is' shown within the dotted rectangles in the upper left-hand portion of Fig. 3. The contacts shown within the dotted lines are controlled by the sequence switch diagrammatically indicated therein. Fig. 4 shows register controlling circuits; Fig. 5 shows a set of regis ters and certaim of the contacts controlled 1 by them; Fig. 6 shows the wiring of additional contacts controlled by the registers of Fig. 5; and Fig. 7 shows sending equipment including a set of counting relays, cona trolling relays and an associated sequence switch.

Associated with each subscribers line is a distributor switch individual to such line,

Each switch consists of a movable brush carrier which may be advanced over a contact bank in which the terminals are arranged in an arc of a circle, each switch having access to'a number of common'trunk' lines, the number of such trunk lines being dependent upon trafic conditions. Since switches operated step by step by means of a ratchet a-nd' pawl device are old in the art, it has not been considered necessary to disclose the mechanical structure of the distributing switch. The switch wipers are advanced in response to-the actuation of a stepping magnet 10 and are held in an advanced position. by means of a retaining pawl which is controlled by the cutoff relay 1 16 and 17.

unwired, and upon the completion of the is completed from grounded battery, wind- Second step, the wipers will engage the tering of relay 29, lower contacts of sequence minal set multipled to the first trunk line. switch spring 30, terminal 28, brush 23,

a The wipers will then be advanced by a huntright-hand .and left-hand? windings of relay 5 ing movement until an idle'trunk is found. 24, inner lower armature of relay 11, the loop 'Thecoin device 334 shown associated with of the calling subscribers line, upper amathe substation 21 may be of any desired ture and back contact of relay 11, to ground. character, theonly requisite being that it is Relays 29 and 24 are energized in this cirprovided with a polarized operating magnet cuit and relay 24 at its inner armature com- 10 and has contacts arranged so that--it is necpletes a holding circuit for magnet 10 from essary to deposit a coin therein in order to grounded battery, winding. of magnet 10, incomplete the circuit of the line relay. The ner armature and front contact of relay 24, mec anism of a coin device suitable for opouter lower armature and back contact of eration in connection with the system of the relay 11, to ground. Magnet'10 can now no 15 present invention is shown in Patent 1,076; longer interrupt its own-circuit and the 285, issued to W. F. Hosford, October 21, brushes are brought to rest. At its outer 1913. A suitable circuit arrangement for a armature, relay 24 completes a holding cirdevice of this character is shown in Patent cuit for itself and relay 29 from grounded 1,243,314, issued October 16, 1917, to A. E. battery, winding of relay 29, lower contacts 20 Lundell. Y a of sequence swrtchspring 30, terminal 28,

. The operation of the system is as follows. brush 23, right-hand winding of relay 24, When the subscriber at substation 21 inserts outer armature and front contact-of relay 24,

a coin in the ,coin device and then removes contact 13, right and left-hand windings of receiver from the switchhook, a circuit message register magnet 70, winding of'cut- 26 be completed from rmded batte ,reof relay 11, to ground. Curtofi relay 11 is slstance 22, terminal 1 brush 23, r'lghtenergized, but magnet 7 0 being'marginal is hand and left-hand windings of. line relay not operated at this time due to the resist- 24, inner lower armature and back Contact of ance of relay 29 being in series with it. Cutcutofi' relay 11, through the loop of the callofi' relay '11 upon operation removes the coni 30 mg subscribers line, upper armature and trol of line relay 24 from the calling sub-.

back contact of relay 11 to ground. Relay scriber and opens the circuit of stepping 24 is ener zed and completes a circuit from magnet 10, which releases without, however, grounded ttery, Winding of stepping mag advancing the switch. since this magnet is net 10, inner armature and front contact of arranged to advance the brushes of the dis- 35 relay 24,0l1ter lower armature and back contributing switch upon its energization. tact of relay 11,toground. In response to the p The energization of relay 29 completes a actuation ofmagnet 10, the brushes 23,25 and circuit from grounded battery, power mag- 26 are advanced one step onto the blank ternet of sequence switch 32, upper, left- hand minals 18, 19 and 20, and at the same time. contact of sequence switch spring 33, conduc- 40 the oft- normal contacts 12 and 13 areclosed, tor 34, r'ighthand. armature and front conand the oil-normal contact 14 is opened. tact of relay 29, to ground, for moving'this' The opening of contact 14 opens the circuit sequence switch out of position 1 and into to cutofi relay 11 and prevents the calling position 2. line from being seized as a called line by any When sequence switch 32 arrives in posi- 45 subscriber, it being understood that conduction-2, circuits are completed to operate the tor 27 leads to the test multiples of the callquick-acting switch shown at the right in ing line at final connector switches with Fig. 2. This switch is utilized to assOciate thebrushes 23, 25 and 26 positioned on a sending apparatus common to the subscribblank terminal set, relay 24 is deiinergized, ers lines with a connecting link taken for 50 but since contaet12 is closed, a steppin ciruse. The preferred form of this switch is 116 cuit is now completed from grounde bate$entially similar construction to the fiery, ding of magnet 10, armature and crossbar switch shown and described in Re- 1 back contact of magnet 10, oil-normal conissue Patent No. 14,236, issued December 26, 12, outer lower armature andback con 1916, to J. N. Reynolds. Only such parts of [65 tact of relay lL to Stepping magthe switch and circuits will be described, as 12o nefi'l0'is e'ne 4 and interrupts its own arenecessaryte understand the operation of circuit. to advance the distributing switch thls type of switch in the present system. brushes over the trunk terminals until an In the present adaptation of the cross-bar idle trunk is found. The test terminals of switch, thereis provided for-each setof send- (l0 idle trunks be characterized by the preslng equipment, a vertical bar 35 a .125 once offull battery potential thereon. ,usy pinralityof sets of multiple contact mem trunks willwbe characterized by a reduced rs such as 36, 37, 38, 39, 40 and 41. For

lien a test rush 23 agape individual connecting link, there is pro terfiinal'28 which, it will be is the vided a horizontal l0ngitudinally movable l5 idle trunk,a circuit crossbar 42. Each horizontal bar is provided with a pluiality of sets of multiple has been actuated to set the preselected bar,

contact members43, 44, 45, 46, 47 and 48-, cont-act 53 individual to such preselected bar there being a set of these contact members in will be closed, and a circuit will then be operative relation to contacts carried by each closed for the test relay 65 by way of wiper of the vertical bars. A setting magnet 49 is 60 and contact 62 to complete a self-inter- 70 provided for each vertical bar and upon enrupting circuit for magnet 59 which will erg'izaltion rotates the'associalted vertical bar advance the wipers 60 and 61 to preselect to an extent such thatvupon longitudinal another idle bar. As long as the wiper 60 movement of a bar 42,the corresponding is passing over a contact 62associated with contact members will be engaged. A trip a busy bar or a set bar, ground will be found magnet 50 common to all the vertical bars on. the terminal 62, either by way of con will then be energized to allow the bar 35 to tact 53 or by way of contact 52, over conducreturn to normalposition where its contact tor 110 as will be presently seen. vWhen an members will be out of the path of any other idle bar is found, testrelay is deenen horizontal bar which may subsequently be gized and the wipers 60 and 61 are brought operated. The contacts 51, 52 and'53 are to rest. 4 I operated in accordance with whetheror not With sequence switch 32 in position 2, a the associated vertical bar is in its normal circuit is completed from grounded battery, position. I right-hand winding of operating magnet 66 When the ope'ratigg lever 56 of a vertical conductor 71, upper right-hand contact 0t trunk bar is operat it is latched in back sequence switch spring 72, right-hand arof a projection 67 in proper relation thereto, mature and front contact of relay 29, to these projections 67 being carried on a pivground. At the same time a circuit is comoted bracket 68 which. is controlled by the pleted from grounded battery, armature and common trip magnet 50. When magnet 50 back contact of relay 58, left-hand winding operates, it allows the set vertical bar to be of magnet 66, armature and back contact of returned to its normal position by the acmagnet 66, conductor 73, lower right-hand 4 tion of a' sprmg member 69 on the latched contact of sequence switch spring 72, rightbar '54. This action of this spring member hand armature and front contact of relay 29,

69 also allows the contact 57 to be closed unto ground. A circuit being. closed through til another bar is set for the purpose preboth windings of magnet 66, this magnet is viously set forth. a energized and attracts its armatures, open- The bar 54 is slidably mounted and is proing the circuit through its left-hand winding vided with notches 55 in proper relation to so that subsequent operation of relay 58 will the operating levers 56 of the res ective verhave no effect on this magnet since the cir- 160 tical bars. Common contact 5 is closed cuit through its right-hand windin is sufliwhile any one of the vertical bars is being cient to maintain it energized. Tl e'actuaset in order to close the circuit of a cutofi tion of magnet '66 operates the horizontal bar relay 58 to prevent any horizontal bar from 42'to move it to the right and cause the enbeing actuated while a vertical bar is being gagement of contacts 43, 44, 45, 46, 47, 48 set. Stepping magnet 59 is provided to adwith contacts 36,37, 38, 39, 40, 41, respecvance wipers 60 and 61 over terminal sets 62 tively. A circuit is now completed from and63, respectively, by means of a ratchet grounded battery, winding of relay 74 (Fig.

and pawl device 64. A test relay 65 deter- 3), lower and upper right-hand contacts of mines which vertical bar is next to be taken sequence switch spring 75, right-hand con- 10 for use. A magnet 66 is individual to each tact of sequence -switch spring 76, armature horizontal bar and is double wound, the a1'- and back contact of relay 77, conductor 7 8,, rangement being such that current through contacts 39 and 46, conductor 79, upper both windings is necessary to cause the magright-hand contact of sequence switch spring net to operate, but after having been ener- 30, left-hand armature and back contact of 15 gized current through the right-hand windrelay 31,terminal 28, brush 23, right-hand ing alone will be sufiicient to maintain its winding of relay 24, outer arn'iature and armatures in an actuated position.-

, front contact of relay 24, off-normal contact The general operation of the switch is 13, windings of magnet 70, winding of cutsuch that a vertical bar 35 will be in its set off relay 11, to ground; Relay 74 is ener- 1 20' position and another trunk bar will be pregized and locks ltself'to. the above traced selected. that is, the wipers 60 and 61 will be ground through its left-hand armature and in engagement with contacts 62 and 63, refront contact. a

spectively. associated with an idle vertical The energization of relay 74 completesa bar, so that when the set bar is released, due circuit from grounded battery, winding of 5 to the actuation of magnet 50, the magnet slow release relay 98, lower contacts of se- 49 associated with the preselected bar 'will quence switch spring 99, conductors 100,

be energized as soon as the latched bar 54 101 and 102, right-hand armature and front has been returned to its normal position. contact of relay 74, to ground. Relay 98 \Vhen the magnet 49 of such preselected bar is energized and completes a circuit from 7 contacts of sequence switch spring 108, left-. hand armature completed from grounded battery, power magnet ofseqiience switch 103, lower righthand contact of sequence switch spring 104, left-hand armature and front contact of relay 98,to ground, for movin this sequence switch'out of position 1 an into position 2 under the control of its master contact 105. With sequence switch 103 in position 2, a circuit is grounded battery, power magnetof sequence switch 106, upper righthandv contact of sequence switch spring 107,

and front contact of'relay 98, to ground, for movin switch out of position 1 an into. position2 under the control of its master contact 109 lever. 56 and the common latch bar 54 will contact 62, associated with is winding of stepping set as soon as be moved to the right by-the spring member 69. A circuit isthen -..completed from grounded battery, winding of. set magnet 49 ofthe vertical bar which had been reseleted contact 63, individual to such ar,

"wiper 61,"left-hand armature and back contact of relay 65, contact 57, to ground. At' the same time a circuit is completed from grounded battery, winding of relay 58, contact 57, to ground. Rela 58 is energized to prevent any horizontal bar from being actuated until the preselectedbar has been set. As soon as the preselected bar has been set, its contact 53 will be closed, whereupon a circuit will be completed from grounded battery, winding'of test relay 65, wiper 60, the 'bar which has just been set,',contact 53,;jto ground. Relay 65' upon energi'zationcompletes a circuit from grounded battery, right-hand armature and front contact of relay 65, magnet 59, armature and front contact of such magnet, to ground. The wipers 60 and 61 are now advanced to preselect another bar. As soon as a bar is found which is not in use nor set, ground will no longer be found on the terminals 62, and relay 65 will .be deenergized, causing the wipers 60 and 61 to come to rest to preselect another trunk bar. It is thus seen that there is always one bar in set position ready for seizure by the next horizontal bar to beac-tuated and that another vertical bar is preselected in readiness to be the set bar has been taken for use and releasedl Simultaneously with the operation of horizontal bar 42 a circuit is completed for relay (Fig.4) from grounded battery,

loop of the calling right-hand, contact this sequence,

Jquence switch spring "per right-hand contact of sequence switch circuit is completed from contact of relay upper left-han tacts of relay 82, conductor 83, contact of sequence switch spring 84, conductor and 47, conductors 8.6 and 87, lower lefthand contact of sequence switch spring 88,

terminal 89, brush 25, inner lower armature and front contact of cutofl' relay 11, the subscribers line, the upper armature and front contact of cutofl relay 11, brush 26, terminal 90, lower of sequence switch 92 and 93, contacts 48 upper contact of se- 95, conductor 96, up-

.spring 91, conductors and 41, conductor 94,

spring 97, to ground." When sequence switch 103 reaches position 2, gizing circuit of relay 98 relay- 80 energized, relay 98 is maintained energized over, a circuit rom grounded battery, winding-of relay armature and front contact of relay 80, conductor 113, right-hand armature and front contact of relay 74, to ground.

A eircuit is now completed from. grounded battery, power switch .114 (Fig. 7),

tor 116, upper right-hand Contact of sequence switch s ring 117, conductors 101 hand armature and front 74,.to ground for moving this sequence switch out of position 1' and into position 2. I

and 102, right In position 2 of sequence switch-114, a

85, contacts 40 the original ener- A is broken, but with.

98, conductor 112,.

magnet of sequence lower left-hand con-- tact of sequence switch spring 115, conduccircuit is completed from groundedbattery, 1'

out of position 2 and into position 3.

A circuit is now completed from grounded battery, windin of line'relay 122 .(Fig. 1),

conductor 127, lower right-hand contact of sequence switch spring 128, left-hand armature and front ground, for movin this sequence switch out of position 2 an into position 3.

, cqnductor .1

. power magnet of sequence switch 106, lower V and lower right-hand con- I contact of relay 122, to I In position 3 of sequence switch 106, a circuit is completed from tus, indicated generally at 129 (Fig. 3), left,

a signaling apparahand contacts ofv sequence switch spring 75,

to.v conductor 83, and then over the line cirthe registers shown in Figs. an

a connection are train will select ment is the same,

cuit. tlllftillgh-lih6 subscribers substation apparatus and-returning circuit'traeed for line relay 80. This signal in the subscribers receiver will inform him that the apparatus is now in readiness for himto start. sending sets of impilses to set The'selector switches used in establishing of the type whose structure and mode of operation is similar to that of the switches shown in Patent No. 1,168,319, issued January .18, 1916, to A. E. Lundell. These switches are each of five hundred line capacity. In the resent arrangement, registers are provide which will be set in accordance with impulses sent out by the calling subscriber, these impulses being transmittedon a decimal basis in accordance with the digits of the number of the called subscriber. The registers will then translate these im pulses to control the selectlve operations of the switches on a non-decimal basis. As

shown in the present disclosure, provision is Y made to have a call extended" through four switches, each of five hundred lines capacity. In accordance with the well-known grouping arrangement, switches of the served. Therefore, the train will be utilized to select an ofiice of 10,000 line capacity. The first switch of the a district office and the second switch of the train will then be operated to select a particular office. By varying the train-10,000 lines may be trict and ofiice selector switc es, an exchange capacity ranging from 4,000,000 to 10,000,000

. lines may be obtained. For instance, if each brush 'of the district selector has access to four groups of twenty-five trunks each, any

one of twenty districts may be selected by the district selector with twenty-five trunk lines running to each district. If the grouping arrangement at the ofiice selector is the same, an one of twenty ofiices may be selected by theofiice selector. Therefore, conn'ection may be extended by means of a district selector and an office selector to any one of ,four hundred ot'fices, each one of 10,000 line This would provide a sys- If each of the rem 4, brushesat the district selector has access to ten groups of trunks of ten lines each, a call may be extended to any one of fifty districts, and if the office selector grouping arrangethe call may then be further extended to any oneof fifty ofiices by mans of an ofiice selector, so that a call may be extended by means of a .district selector and an ofiice selector to any one of twentyfive hundred ofiices.'each of 10.000 line capacity. As a result, this grouping arrange ment would provide an exchange system 0 25,000,000 line capacity. The trunk. layout would be dependent upon traffic conditions to ground over the by means of the latter two he first two switches of roup at the disher in the selected iductor 134, left-hand windin and since the particular number of trunks per group is immaterial-in the present arrangement, no. specific groupin will be described for the district and o ce switches. At the incoming swtich, which is'the third switch in the train; eachof the five brushes of the selector has access to four groups ot twenty-five trunk-lines each, each of .these trunklines terminating in a final connector switch. At the final connector switch each of the five brushes has access to ten groups of ten lines each, each of these lines leading to a subscribers station.

In order that the calling subscriber may not have to carry in mind a large number of digits, it is proposed to designate the desired office number by means of letters of the alphabet and three series of impulses will be sent to set three registers to control the first two switches of the train. These three registers will control brush and group selection at the district selector and brush and group selection at the ofiice selector. An impulse sending device of any well-known type will be used, being arranged merely to cause a desired number of circuit interruptions in response to'the operation of a finger wheel. The sender dial might be lettered so that in addition to a finger hold for each digit, the hold characterized by the No. 0, which would be arran ed to send one impulse, may also bear the etter A. .The No. 1 finger hold may bear the characterization B and 1. In this'way the lettering on the dial plate complete would be A-0, B1, E-A, F-5, G-6, H-7,I-8, J- -9.

It will be assumed that the calling subscriber desires to establish connection to a subscriber whose number is 6843 in an ofiice characterized by the three letters J-J--E. The subscriber will therefore first operate his impulse dial to send ten im ulses, then to send ten more impulsesand t en to send five impulses, after which he will proceed to send the digits constfifiuting the desired numo ce. to the first series of impulses, line relay 80 is intermittently Relay 98 being slow, to release during the sending of the \of' thevv fact that its cir- In response the circuit of interrupted.

remains energized impulses, in spite 'cuit is intermittently broken at the armature and front contact of relay 80. With. the first deenergization of rela 80, a circuit is completed from groun ed battery, zo right hand armature and back contact of relay 130glower right-hand contact ,of. sequence switch spring ,131, conductor 132, up-

per contacts of register. spring 133, co

conductor.- 136, armature an back contact r of relay 80, conductors 113 and 102, righthand armdture and front contact of relay 74. to ground. In order C-2, D--3, 10a

of relay 1 5,

that the setting operation of the v register switch with which they are asst):

ciated, the upper contacts, will be closed,

while in the even positions of the switch the lower contacts will be closed. In each case the normal position of the switch will be considered as an odd position. I

. Relay 135 is energized in the above traced circuit and completes a circuit from grounded battery, power magnet of register 137, upper contact of register spring 138 .(the upper contact being closed, since the register is in its normal position), conductor 139, lower right-hand contact of sequence switch spring 140, left-hand armature and front contact of relay 135, to ground, for moving this register out of its normal position and into position 0. Relay 135 upon energization also completes two lockingQ circuits for itself by way of its right-hand armature. I The first of these extends froin grounded battery, right-hand armature and front contact of relay 135, left-hand winding of I 136, armature and bac contact of relay 80, to ground over the path described, and maintains this relay energized until line relay 80 is energized in response to the co n--- interruption of the line"- locking circuit of relay right pletion of the first circuit. The second 135 extends from grounded battery, hand armature and front contact of 135, right-hand winding of relay relay energizes. In response to the next denergization of relay 80, with position 0, a circuit is completed from grounded battery, right-hand armature and back contact of relay 135, upper left-hand contact of sequence switch spring 145, conductor 146, lower contacts of register spring 142, conductor 147,1eft-hand winding of rethe register 137 in spring 149, conductor 150, left-handarmature and front contact of relay 130, to ground, for moving the register out of po-.

be understood, it is under-- ounded{' batteryfiright hand armature and 1 and relay relay 135, conductor ing circuits for relay 135 identical with f..thosefpreviously described in;the descripcompleted and broken the"gl;i n'e circuit, relay 130 is'again energized 135, eon; ductor 141, upper contacts of register spring,

80 energized, 4

lay 130, conductor 136, armature and back switcli' spring 152,

sition- 0 and into position 1. Relayv 130 upon energization completes two locking circuits for itself through its right-hand armature, one oftheseeircuits extending. from ront contact of relay 130, right-hand winding of relay 130, conductor 151, lower, contacts of register spring 133, conductor 143, upper left-hand contact of sequence switch spring 144, to ground. The other-locking circuit extends from grounded batteryQright- 7 hand armature and front contact of relay 130, left-hand winding of relay 130, conductor 136, armature and back contact of relay 80, toground over the path previously'described. As before, when the line circuit is againclosed, the resultant energization of relay opens the locking circuit throu h the left-hand winding of relay 130 and-t 1e moving of relay 137 out of; position 0 and position 1 will open the circuit through into the lower contacts of register spring 133 130 deenergizes. In response to interruption of the line circuit, relay .135 is energized to advance register 137 out of position 1 and into position 2, over circuits identical with those previously traced for moving the register out of "its normal position .and'into position Q. Lockthe thir tionb he operation of this relayare also in the same manner. In response to the fourth interruption of .100 'zto-move'register 137 from position 2 to position 3 in the same manner as described for moving it from --position 0 to position 1, the ci'ygle of operation of relay 130 in this a case ing the same as when it was previ-- .ously brought into use. It will thus be seen that for each interruption of the line circuit, the register 137 will be advanced one position. At the termination of the first series of impulses, at which time ten interruptions of the line circuit will have occurred, the register 137 will have advanced ten ste into position 9. Relay is energize in response to the last denergization of line relay 80.

. It is to be observed that as soon as register 137 left its normal position,acircu it was completed for relay 119 (Fig. 4), cuit extending from grounded battery, wind- 119, lower contact of conductor 153, contact of register spring 154', lower contacts of'regis tcnsprings 155, 156, 157, 158, 159, in series, conductor 161, armature and front contact of relay 80, to ground, as described. 125 This circuit is completed momentarily each time that relay 80 is energized during the send ng of the first series of impulses. Rc-

lay 119 is, however, designed to be slow to pull up its armatures. and therefore these momentary circuit closures will not allow it to attract its armatures. However, after register 137 has been positioned and during the interval between the sending of the first and second series of impulses,'relay'80 remains energize for a relatively long time and as a result relay 119 attracts its armatures. Relay 119 at its right-hand armature completes a circuit from grounded battery, power magnet of sequence switch 106, lower left-hand contact of sequence switch spring 107, conductor 162, right-hand armature and front contact ofrelay 119 to ground, for moving this sequence switch out of position 3 and into position 4. When sequence switch 106 leaves position'3, the energizing circuit of relay 119 is broken at the lower contact of sequence switch spring 152, and

of'relay 80, but does not become effective relay 119 denergizes, thus opening the driving circuit of sequence switch 106 to revent this sequence switch from moving through more than one position. 7 s

In position 4 01 sequence switch 106 the second series of impulses'may be received.

Ten impulses will be sent to advance register 163 ten steps into position 9. At this time relays 130 and 135 function to control the advanceof register 163 in a manner substantially similar to that previously described. At this time, however, the energizing circuit for relay right-hand contact of sequence switch spring 131, through the upper contacts of re ister spring 164 and then by way of con uctor 134, as previously described. The energizing circuit of relay 130 extends by way of the upper right-hand contact of sequence switch spring 145 and the lower contacts of sequence switch spring 165 and thence by way of conductor 147 throughthe winding of rela 130 and to ground, as described. Since t e operation ofsetting register 163 is fundamentally similar to that of setting register 137, it is thought that it need not be described in detail. It is to be observed until after the sending of the series of impulses. VVhen relay 119 is energized, a circuitis completed from grounded battery,

power-magnet of sequence switch .106, lower left-hand contact of sequence switch spring 107, conductor 162, right-hand armature and 135 extends through the upper moving this sequence switch out of position .4'and into position 5.

The subscriber continues sending the complete number of sets of impulses and as a result register 167 willbe set in position 4, register 168 will be set in position 6, register 169 will beset in position 8, register 170 will'be set in position 4, register 171 will be set in position 3. Upon the completion of the setting of register 167, the energization of relay 119 will advance switch 106 from front contact of relay 119, to ground, for 1 position 5 to position 6, the completion of the setting of register 168 will advance sequence switch 106 into position 7, the completion of the setting of register 169 will advance sequence switch 106 into position 8, the completion of the setting of register 170 will advance sequence switch 106 into position 9, and when the last re ister 171 is positioned, be advancedout of osition 9 and into position 10. Relay 119 is held energized in position 10 due to a circuit from grounded battery, winding of relay 119, upper left-hand contact of sequence switch spring 152, right hand armature and front contact of relay 119, to ground;

When sequence switch 106 has reached position 5, at which time registers 137 and 163 will have been positioned, these being the registers that control the o eration of the "selector switch indicated in Fig. 1, the selective operation of this switch is started. A circuit is completed from grounded battery, winding of relay 122 (Fig. 1), upper contacts of sequence switch spring 123, conductors 17 2 and 173, contacts 45 and 38, conductor 174, winding of polarized overflow relay 175, armature and back contact of the 0 countingrelay, winding of stepping-relay 176, upper contact of sequenceswitch spring ture and front contact of relay 98, inner left-hand armature and back contact of relay 82, lower left-hand cohtact of sequence switch spring 126, conductor 125, contacts 37 and 44, conductor 124, lower right and upper.

left-hand contacts of sequence switch spring 179, resistance 180, conductor 181, lower 182, upper right-hand contact of sequence sequence switch llOfi will;

177, conductor 178, right-hand armaright-hand contact of sequence switch spring switch spring 183, to ground. Relay 122 is 4 energized in this circuit and locks itself to' conductor 173 by way of its right-hand armature and front c0ntact.. At its left-hand armature, relay 122' completes a circuit from grounded battery, power magnet of sequence switch'32, conductor 127', lower righthand contact of sequence switch spring 128,

left-hand armature and front contact of re-- lay 122, to ground, for moving this sequence switch out of position 3 and into position 4. It is to be noted that relays 175 and 176 are included in the abovetraced energizing counting relay, windin 2o pleted from grounded battery, windin circuitfor relay 122. Relay 175 is polarized and does not ener ize in this circuit. Stepping relay 17 6 is, owever, energized in this circuit and completes a circuit from ground,

5 armature and front contact of relay 176,-

upper left-hand contact of sequence switch spring 184, conductor 185,.upper left-hand contact of register spring 186, conductor 187, armature and back contact of the No. 4'

of the No.4 counting relay, to grounded battery. The No. 4 counting relay is energized and prepares a circuit for the No. 4 counting relay in the well-known manner, the energization of the 5 No. 4 counting relay being subject to the deenergization of the stepping relay 176, as is well-known in the art. i

In position 4 of sequence switch 32 and with relay122 energized, a circuit is comof .updrive magnet 188, upper contacts 0 sequence switch spring 189, left-hand armature and front contact of relay 122, to ground. The brush-carrying shaft 190 is movedupWard under the control of magnet A 188 to position one of the brush sets carried thereby in readiness to be trippedx As the brush rod 190 moves upward, a brush 191 is brought into engagement with a conduct- 3o ing segment of a commutator 192. As soon as .the brush 191 engages a conducting seg- 'ment of commutator 192, the stepping relay 176 is shunted out over a path extending from grounded battery, winding of relay 85 122, right-hand armature and front contact of relay 122, .conductor 172, upper righthand contact of sequence switch spring 123,

conductor 193, upper contact of sequence switch s ring 194, conductor 195, commuta- '40 tor 19 2, rush 191, conductor 196, lower lefthand contact of sequence switch spring 197, to ground. As a result of this shunting action, relay 176 is deenergized and allows the No.. 4 counting relay to be energized 46 due to a circuit being closed from grounded r v battery, windings of No. 4 and No. 4 count ing relays, armature and front contact of' 1 No. 4 counting relay, contact of sequence switch spring 246, conductor 247, upper left- 50 hand contact of sequence switch spring 245 'to ground. Counting relays are now successively actuated in response .to the advance of brush 191, and when the No. 0 countin is energized, at which time the brush will have been advanced into a posi tion where the fifth brush set may be tripped 'into operative relation with the section of the contact bank served by it, the lower branch of the fundamental circuit will be open; and when a moment later brush 191 engages an insulating segment of commutator 192, the circuit of relay 122 is broken. Relay 122 deenergizes and completes a circuit from grounded batter ,power magnet of sequence switch 32, con uctor 127, upper right-hand contact of sequence switch spring 128, left-hand armature and back contact of relay 122, to ground, for moving this sequence switch out of position 4 and into position 5. i

At the sender a relay 198 is energized in parallel with the No. 0' counting relay due to a circuit being closed from grounded bat tery, winding of No. 0 counting relay, Windings of relays No. 0 and 198 in parallel, armature and front contact of No. 0 counting relay, contact of sequence switch spring 246, conductor 247, upper left-hand contact of sequence switch spring 245 to ground; Upon the energization of relay 198 a circuit is completed from grounded battery, power magnet of sequence switch 114, upper rightpower magnet of sequence switch 114, up-

per right-hand contact of sequence switch spring 199, conductor 200, upper right-hand contact of sequence switch spring 97, to ground, it being assumed that sequence switch 106 will have by this time advanced at least as far as position 7 in response to the successive setting of the various registers. As soonv as sequence switch 32 reaches position 4%, a circuit is completed from grounded battery, winding of trip magnet 201, upper right-hand contact of sequence switch spring 202, lower left-hand contact of sequence switch spring 197; to ground.

trip rod 203 so that uponsubsequent upward movement of brush rod 190, the fifth set of brushes will be tripped.

The energization of magnet 201 operates a As soon as sequence switch 114 reaches position 4 and sequence switch 32 reaches position 5, a circuit is completed from grounded battery, winding of relay 122, upper contacts of sequence switch spring 123, conductors 172 and173 to ground over the path previously described. Relay 122 is energized and locks itself to conductor 173 and at its left-hand armature completes a circuit from grounded battery, power magnet of sequence switch 32, conductor 127, lower ri t-hand contact of sequence, switch spring 1 8, left-hand armature and front contact of relay 122, to ground, for moving this sequence switch out of position 5 and into position 6. As before, the energizing circuit of relay 122 includes the stepping relav 176, and at this time the energization of relay 176 completes a circuit from ground,

armature ands front contact of relay 176, upper right-hand contact of sequence switch spring 184, conductor 204, upper contact of register spring- 205, upper left-hand con tact of register spring 206, conductor 207,

armature and back contact of the No. 7 counting relay, winding of the No. 7 counting relay, to grounded battery. The U0. 7 counting relay is energized and prepares a circuit for the No. 7 counting relay in the well-known manner.

In position 6 of sequence switch 32 and with relay 122 energized, a circuit is completed from grounded battery, winding of updrive magnet 188, upper contacts of sequence switch spring 189, left-hand armature and front contact of relay 122, to ground. The brush rod 190 is again moved upwardly to advance the fifth set of brushes in a group-selecting movement. At this time when commutator brush 209 engages the conducting segment of commutator 210, the stepping relay 176 is shunted out by a circuit traceable from grounded battery,

'winding of relay 122, right-hand armature and front contact of relay 122, upper righthand contact of sequence switch spring 123, conductor 193, lower contact of sequence switch spring 194, conductor 211, conmiutator 210, brush 209, conductor 196, lower left-hand contact of sequence switch spring 197, to ground. Stepping relay 176 is de energized and alloWs the No. 7 counting relay to energize. The counting relays are successively actuated in response to the in termittent shunting out of steppin relay 176, and when the N o. 0 counting relay and relay 198 are energized, the lower branch of the locking circuit of relay 122 is broken; and when a moment later brush 209 engages an insulating segment of commutator 210, relay 122 is denergized. A circuit is then completely from grounded battery, power magnet of sequence switch 32, conductor 127, upper right-hand contact of sequence switch spring 128, lefthand armature and back contact of relay 122, to ground, for moving this sequence switch out of position 6 and into position 7.

The energization of 'relay 198 completes a circuit from grounded battery, power magnet of sequence switch 114, upper right-hand contact of sequence switch spring 115, armature and front contact of relay 198, to ground, for moving this sequence switch out of position 4 and into position 5. Sequence switch 114 is then moved out of position 5 and into posit-ion 6 by means of a circuit extending from' grounded battery, power magnet of sequence switch 114, lower, contact of sequence switch spring 363, conductor 364. lower contact of sequence switch spring 365,

to ground, provided the sequence switch 106 has reached position 7 at this time.

The selected brush set has now been advanced to a position such that the brushes are engaging the lowermost set of terminals 1 in the seventh group of terminals served by this brush set. Busy trunk lines are characterized by the presence of ground potential on their test terminals. It will be as sumed that the lowermost trunk in the group is busy.

In position 7 of sequence switch 32, a circuit is completed from grounded battery, left-hand winding of relay 212, lower righthand contact of sequence switch spring 213,

right-hand contact of sequence switch spring 1 128, inner armature and front contact of relay 212, to ground. for movingthis sequence switch out of position 7 and into position 8.

In position 8 of sequence switch 32, a circuit is completed from grounded battery, winding of updrive magnet 188, lower contacts of sequence switch spring 202. inner armature and front contact of relay 212, to ground. The selected brush set is now ad vanced in a trunk-hunting movement, and when the test brush 216 encounters a test terminal 217 to which no ground is connected, the locking circuit through the righthand winding of relay 212 is broken. Re-

.lay 212 is. however. maintained energized a moment longer by means of a circuit extending from grounded battery, through its left-hand winding. upper right-hand contact of sequence switch spring 2 13. conductor 218, commutator219. brush 220, lower left-hand contact of sequence switch spring 202. right-hand armature and front contact of relay 212. to ground. As soon as brush 220 engages an insulating segment of commutator 219, at which time the brush set will be accurately centered on the terminals of the desired trunk line, relay 212 is deenergized and opens the circuit of magnet 188 to allow the brush set to be brought to rest. The deenergization of relay 212 completes a circuit from grounded battery, power magnet oi sequence switch 32. conductor 127. lower left-hand contact of sequence switch spring 128. inner armature and back contact of relav 212, to ground, for moving this sequence switch out of position '8 and into position 10.

A fundamental circuit is now completed from grounded battery at the oflice selector associated with the seizedtrunk, over conductor 230, terminal. 234, brush 231, lower contact of sequence switch spring 232, conductors 233 and 173, contacts 45 and 38, conductor 174, relay 175', armature and back contact of No. 0' counting relay, winding of stepping magnet 176, upper contact of sequence switch spring 177, conductor 178,-

upper contact of sequence switch spring 126 (it being assumed that the sequence switch 106 has reached .its seventh posit-ion), conductor 125, contacts 37 and 44, conductor 124, lower contact of sequence switch spring 235, brush 236, terminal 237 to ground at the office selector. Through any appropriate'means at the office selector, the switch power magnet will energize and brush selection willtake place in substantially the same inanner as that described in connection with the district selector. The oflice selector in its movement will causeinterruptions of theflow of current to the stepping relay 17 6 by means of an interrupter corresponding to the commutator 192 and. brush 191 at the district selector.

The closure of the fundamental circuit causes the energization of relay 17 6. Upon the energization of the stepping relay 176, a circuit is completed from ground, armature and front contact of relays 176, lower contact of sequence switch spring 184, lower contact of'register spring 249, lower contact of register spring 250, upper contactknown manner until the No. 0 counting relay and relay L98 are energized. The No. 0 counting relay opens the fundamental circuit, thus ending the first cycle-of operations and stopping the oflice selector in a po- I sition to trip the fifth set of brushes.

The energization of relay -198' closes the.

circuit from grounded battery, power magnet of sequence switch 114, upper right-hand contact of sequence switch spring 115, armature and front contact of relay 198'to ground for moving the sequence switch out of position 6 and into position 7. Sequence switch 114 immediately moves out of position 7 and into position 8, due to a circuit being closed from grounded battery, power magnet of sequence switch 114', lower contact of sequence switch spring 363, conductor 364, lowercontact of sequence switch spring 365 to ground,

In passing fromposition 6 to position 8, the sequence switch 114 interrupts at contacts 243 and..246 the holding circuits of the counting relays.

In position 8 of the sequence switch 114, the fundamental circuit is again closed through to the office selector and again causes the energization of the updrive mag net at the office selector. Group selection at the oflice selector will now take place. As the switch shaft is elevated, the current through the stepping relay 176 will be shunted by means of a shunt circuit through a commutator similar to the commutator-210 at the district selector. The first energiza tion of the stepping relay 176 completes a circuit from 'ound, armature and front contact of relay 1 76, upper left-hand contact of sequence switch-spring'255, conductor 256, lower contact of register spring 257, upper contact of register spring258, lower left-hand contact of register spring 252, conductor 208, armature and back contact of No. 3 counting relay, winding of No. 3 counting relay to grounded battery. The counting relays will be actuated in the samemanner as above described. a

As soon as the No. 0 counting relay is energized, the fundamental circuit is opened, thus stopping the selected set of brushes of the office selector at the bottom of the fourth this sequence switch out of position 8 and into position 9 Theholding circuit of the counting relays is interrupted at contacts 243 and 246 as before.

As soon as the office selector has seized a trunk leading to an idle incoming selector and sequence switch reaches position 9, the fundamental circuitwill again be closed over the circuit above described from conductor 174 then through resistance 259, winding of relay 260, lower contact of 'se-- quence switch spring 177, conductor 178 to ground at. the incoming selector. Relay 260 becomes energized and completes, if sequence switch 106 has reached position 10, a circuit from grounded battery, power magnet of sequence switch 114, upper "contacts of se-- quence switch spring 115-, armature and front contacts of relay 260 to ground over conductor" 262 for moying this sequence 12 v switch out of position 9 and into position 10. In position 10, the circuit through relay 260 is opened at the lower contact of sequence switch spring 177 and the fundamental circuit is again closed through relay 17 6. Upon the energization of relay 17 6, a circuit is closed from ground, armature and front contact of relay 17 6, upper right-hand contact of sequence switch spring 255, conducter spring261, conductor 208, armature and 'back contact of No. 3' counting relay, winding of No. 3 counting relay to grounded battery. Brush selection at the incoming selector now takes place and as the switch is elevated, the stepping'relay 176 is denergized and the counting relays actuated in the same manner as above described. As soon as the No. counting relay is energized the fundamental circuit is opened, thus terminating the first cycle of operations or the brush selection at the incoming selector. With the switch in a position to trip the fourth set of brushes upon the energization of relay 198, the above described circuit for the power magnet sequence switch 114 is closed for moving this sequence switch out of position and into position 11. The sequence switch 114 is immediately moved out of position 11 and into position 12 due to a circuit from grounded .battery, power magnet of sequence-switch 114, lower left-hand con- I tact of sequence switch spring 199, conductor 262, lower right-hand contact of sequenceswitch spring 245 to ground.

As soon as the sequence switch 114 leaves position 10, the holding circuits for the counting relays are opened at contacts 243 and 246 as before. When the sequence switch 114 reaches position 12, the fundamental circuit is again closed through to the incoming selector. This causes the operation of the incoming selector switch power magnet and connects an interrupter,

similar to commutator 210' of the district selector, in shunt with the fundamental circuit Group selection at the incoming selector now takes place. Upon the energization of relay 1%, a circuit is closed from ground, armature and front contact of relay 176, lower right-hand contact of se-' quence switch spring 255, conductor 263,, lower contact of sequence switch spring 264,

upper contact of register spring 265, conductor 461, armature and back contact of Np. 1' counting relay, winding of No. 1 counting relay to grounded battery. As the incoming selector is operated, the counting relays will be actuated in the same manner as above described.

The energization of No. 0' counting relay opens the fundamental circuit, thus terminating the group selection at the incoming selector. The incoming selector will now automatically hunt for a trunk leading to an idle final'selector. Upon the energization of relay 198 the above described circiiit for the power magnet of sequence switch 114 is closed and moves this sequence switch out of position 12 and into position 13. This sequence switch is immediately moved out of position 13 and into position 14. due to the circuit previously described through the lower left-hand contact of sequence switch spring 199.

sequence switch spring 267, conductor 208,

armature and back contact of No. 3 counting relay, winding of No. 3 counting relay togroundedbattefy. The counting relays are actuated in the same manner as above described until the counting relay No. 0' and relay 198 are energized. No. 0 counting relay interrupts the fundamental circuit, thus terminating the brush selection at the final selector with the switch in a position to trip. its fourth set of brushes. The energization of relay 198 closes the above traced circuit for the power magnet of sequence switch 114 to move this sequence switch out of position 14 and into position 15. This sequence switch is immediately moved out of position 15 and into position 16, due to the above traced circuit through the lower left-hand contact of sequence switch spring 199. As soon as the sequence switch 114 leaves position 14, the holding circuits for the counting relays are interrupted at the sequence switch springs 243 and 246.

' relay 176, a. circuit is completed from ground armature and front contact of re-. lay 176, upper left-hand contact of sequence switch spring 268, conductor. 269, upper right-hand contact of register spring 270, conductor 187, armature and back contact of No. 4? counting relay, winding of No. 4 counting relay to grounded battery The counting relays are actuated in the same manner .as above described until the No. 0'. counting relay and relay 198 are energized. The energization of the No. 0 counting relay interrupts the fundamental circuit, thus terminating the group selection of the final selector with the selected set of brushes at the bottom of the fifth group of terminals in which the called subscribers line terminals are located. The energization of relay 198 closes the above traced circuit for the power magnet of sequence switch 114by moving this sequence switch out of position 16' and into position 17. This sequence switch is immediately moved out of position 17 and into position 18. due to the above, traced circuitthrough ,the lower left-hand contact of sequence switch spring 199. As

a spring 268, conductor 271, lower right-hand terminals of the called line.

soon as the sequence switch 114 leaves posirnormal contact 13, right-hand and lefthand tion 16, the holding circuits for the counting relays are opened at the sequence switch springs 243 and 246.

When the sequence switch 114 reaches position 18, the fundamental circuit is again closed and units selection at the final selector takes place. Upon the energization of relay 176, a circuit is closed from ground, armature and front contact of relay 176, upper right-hand contact of sequence switch contact of register spring 27 2,conductor 208, armature and back contact of No. 3 counting relay, winding of No. 3 counting relay to grounded battery. The counting relays are actuated in the same manner as above described until the selected set of brushes of the final selector has engaged the fourth set of terminals in the selected group, at

mental circuit, thus stopping the selected set of brushes of the final selector on the Ringing current will now be applied to the called line at the incoming selector in the well-known manner,

Upon the energization of relay 198, a cir- I cuit is closed from grounded battery, power ture and front contact of relay 74, to ground.

'magnetof sequence switch 106, lower righthand contact of sequence switch spring 107,

conductor 118, left-handed armature and front contact of relay 119, which is energized at this time in the manner previously described, conductor 380, upper'right-hand contact of sequence switch spring 290, armature and front contact of relay 198 to ground, for moving sequence switch 106 out of position 10 and into position 12. A circuit is now closed from grounded battery, left-hand windingof relay 212, Fig. 1, lower left-hand contact of sequence switch spring 213, conductor 291, contacts 43 and 36, conductors 292. and 293, lower contact of sequence switch spring 117, right-hand arma- Relay 212 becomes energized and completes a circuit from grounded battery, power magnet of sequence switch 32, conductor 127,

' lower right-hand contact of sequence switch spring128, inner armature and front contact of relay 212 to ground, by moving this sequence switch out of position 10 and into position 12. I

In position 11 of sequence switch 32, a circuit is completed from grounded battery, winding of relay 29 (which became deenergized when sequence switch 32 left position 4).- lower right-hand contact of sequence switch spring 30,1eft-hand armature and back contact of relay 31, terminal 28, brush I 23, right-hand winding of relay 24. outer armature and front contact of relay 24, 011'- windings of relay 70, winding of cutoff relay ll'to ground. This circuit is maintained until sequence switch 32 reaches position 16.-

As soon as the sequence switch 32 leaves position 11, the holding circuit of relay 74 is opened at the upper contact of sequence v switch spring 30, but this relay is still held energized, due to a circuit being closed-from conductor 79, lower contacts of sequence switch spring 189, conductor 173, contacts 45 and 38, conductor 174, upper left-hand and lower right-hand contacts of sequence switch spring 293, conductor 294, resistance 295, lower right-hand contact of sequence switch spring 111 to ground. Since the relay 74 is still energized, the above traced circuit of relay 212 is also held closed and causes sequence switch 32 to move out of position 12, through'position 13, and into 35 position 14. When sequence switch 32 leaves position 11, a new holding circuit for magnet 66 is completed through conductor 71,

right-hand contacts of sequence switch spring 327, conductor 291 to ground over the circuit described'for relay-212.

As soon as sequence switch 32 leaves position 13.1}, a circuit is closed from grounded battery, lower left-hand winding of repeating coil 297, winding of supervisory relay- 298, lower right-hand contact of sequence switch spring 88, terminal 89, brush 25, inner lower armature and front contact of relay 11, loop of the calling substation, ,upper As soon as the sequence switch 32 leaves switch spring 189, thereby causing the deenergization of relays 74 and 212 and mag- .net 66. The deenergi'zation of magnet 66 releases the line bar 42 to its normal position. while the deenergization of relay 74 closes a circuit from grounded battery,

position 13, the holding circuit-of relay 74 is opened at the lower contacts of sequence power magnet of sequence switch 106, upper right-hand contact of sequence switch sprmg 296, right-hand armature and back contact of relay 74, to ground for moving this sequence switch out of position 12 and into position 15.

The circuit for relay 98 is also interrupted at the right-hand armature-and front con--v tact of relay 74. .When the sequence switch switch spring 91.

position a grounded battery, power magnet of reglster 32 leaves position 133;, the circuit of relay 80 is opened at the lower left-hand contact of sequence switch spring 88 and at the lower right-hand contact of the sequence Thedeenergization of relay 98 completes a circuit from grounded battery, power magnet of sequence switch 103, upper contact of sequence switch spring 104, left-hand armature and back contact of relay 98, to ground by moving the sequence switch out of position 2, through position 18 to its normal position.

When the sequence switch 106 reached position 12, a circuit was completed from grounded battery, power magnet or register- 171, upper contact of register spring .298, conductor 299, lower contact of sequence switch spring 97, to ground by moving this register back to its normal position. As soon as the register 171 reaches its normal circuit is completed from 170, upper contact of register spring 300, lower contact of register spring 298, to

ground over the circuit previously described.

In a similar manner, registers 169,168, 167, 163 and 13.7 are successively moved into their normal positions,

As soon as all of these registers reach their normal positions, a circuit is closed from grounded battery, power magnet of sequence switch 106, lower contact of sequence switch spring 296, conductor 301, lower contacts of register springs 302, 303, 304:, 305, 306, 300 and 298 in series, conductor 299,-lower right-hand contact of sequence switch spring 97, to ground, for moving this sequence switchiout of position 15 and into position 16. Sequence switch 106 is moved out of position 16 and into position 17 due to a circuit completed from grounded battery, power magnet of sequence switch 106, upper left-hand contact of: sequence switch spring 196, lower right-hand contact of sequence switch spring 3 11 to ground. As soon as the sequence switch 106 reachesposition 17 it is immediately moved into position 18 due to a I ductor 307, lower left-hand contact of sequence switch spring 2 15, to ground for moving this sequence switch out of posltion 18 and into position 1. X

As soon as the sequence switch 114 reaches position 1, a circuit is completed from grounded battery, power magnet of sequence switch 106, lower left-hand contact of se-' quence switch spring 107, conductors 162 and 308, lower contact of sequence switch spring 121 to ground by moving the sequence switch 106 out of position 18 and into position 1.

As soon as the called party removes his receiver, the polarized relay 309 becomes energized in the well-known manner. A circuit is now closed from grounded battery, power magnet of sequence switch 32, lower left-hand contact of sequence switch spring 33, upper left-hand and lower right-hand contacts of sequence switch spring 310, conductor 181, armature and front contact of relay 309, upper right-hand contact of se quence switch spring 182, upper right-hand contact of sequence switch spring 183, to

round, for moving this sequence switch out of position 14 and into position 15.

A circuit is now closed from grounded battery, winding of relay 273 (F ig, 1), lower left-hand and upper left-hand contacts of sequence switch spring 179, resistance 180, armature and front contact of relay 309, upper right-hand contact of sequence switch spring 182, upper right-hand contact of sequence switch spring 183 to ground. Relay 273 becomes energized and closes a locking circuit for itself at its lefthand armature and. front contact.

The subscribers are now connected for conversation As soon as the parties are through talking, and the calling subscriber at substation 21 restores his receiver upon the switchhook, relay 298 denergizes and completes a circuit to operate the quick acting switch shown at the left of Fig. 2. This switch is used to associate a common coin collect, coin return and metering apparatus with a connecting link taken for use. The preferred form of this switch is essentially the same in construction and operation as In the present arrangement of the crossbar switch there is provided for each com mon coin and metering apparatus, a vertlcal bar 286 carrying a plurality of sets of multiple contactmembers such as 274, 275, 276, 277, 278 and 279. For each individual connecting link there is provided a horizontal longitudinal movable bar. Each horizontal bar is provided with a plurality of sets of multiple cont-act members 280, 281, 282, 283, 281 and 285. Each set of these contact mem-* hers is in operative relation to the contacts carried by a different vertical bar. A set magnet 288 is provided for each'vertical bar and upcgn energization, rotates the associ-. ated vertical bar to an extent such that upon the longitudinal movement of the bar 287, the corresponding contact members will be engaged. An operating magnet 239 is provided for each horizontal bar 287. Since the construction and operation is substantially. the same as that above described for

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