US1517315A

US1517315A - Telephone-exchange system

Info

Publication number: US1517315A
Application number: US428578A
Authority: US
Inventors: William A Rhodes
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp
Priority date: 1920-12-06
Filing date: 1920-12-06
Publication date: 1924-12-02
Anticipated expiration: 1941-12-02

Description

Dec. 2, 1924 1,517,315 W. A. RHODES TELEPHONE EXCHANGE SYSTEM 0^/ THous. LEVER.

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W. A. RHODES TELEPHONE EXCHANGE 'SYSTEM v Dec. 6, -1920 5 Sheets-Shea?l 4 j MA@ W. A. RHODES TELEPHONE- EXCHANGE SYSTEM Filed Dec. 6. 1920 5 Sheets-Sinaai. 5

' Joe VT" 50a Inl n n Hl Patented Dec. 2, 1924.

narran sra'rss wiLLrAM A. Rnonns, or NEW YORK, n. Y.,

ASSIGNOR T0 AMERlKsm'` TELEPHONE ANI) TELEGRAPI-I COMPANY, A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed December G, 1920. Serial No. 428,578.

To all whom t may concern:

Be it known that I, WILLIAM A. RHODES, residing at New York, in the county of New York and State of New York, have invented certain Improvements in Telephone-EX- change Syst-ems, of which the following is a specification.

This invention relates to telephone eX- change systems and more particularly to systems of the character wherein automatic switches are employed for setting up connections between subscribers lines.

In telephone exchanges where certain ollices are equipped with manual switching apparatus, such as operators conecting circuits, for establishing talking connections while other offices are provided with machine switches it is necessary, in order to enable the'establishment of nterollice connections, to provide the operators with means for controlling the selective movements of such switches. For this purpose, the operators positions are provided with register sending mechanisms upon which the 0perator may record the designations of called lines and which thereafter operate to control the selective switches in the extension. of the connection. The incoming calls may originate on local subscribers7 lines terminating directly at the operators position, or they may be extended to the operators position over interolfice trunk lines from distant offices. In either event, the operator responds and ascertains the name of the called office and the number of the wanted line therein. On learning that the desired connection is one that must be built up through the. agency of automatic switches, she proceeds to record the designation on the register sender at her position and by means of a cord circuit extends the calling line to the first of such switches. rIhe switches are then positioned `under the control of the sender to complete the connection to the wanted line.

Register senders of the class suitable for controlling selective switches of the type considered herein usually comprise a plurality of register switches, which may be operated either in a step-by-step manner, or by means of a constantly driven power member. "Where the register senders are located in the same oliice with the automatic switches, acommon source of power may be provided for operating both the registers and the switches. In systems of the character above outlined, however, the controlling sendersV are frequently situated in oliices distant from the automatic switches. Consequently, it is desirable to obviate as far as possible the use of power equipment merely for the purpose of operating the sender registers.

With this in view, the present invention has for its object the provision of a register' sender including a plurality of manually operable registers arranged to be variably adjusted to set positions, and which serve while in their set positions to determine the operation of a counting mechanism for controlling the selective movement of automatic switches. i i

A feature of the invention relates to an i arrangement wherein a series of counting relays are variably operated in accordance with the set positions of the manually operable registers for controlling the automatic switches.

Other and further features of the invention will become apparent from a consideration of the following description and the appended claims.

In the drawing Figs. l, 2, 8 and L with Fig. 2 placed beneath F ig. l and Figs. 3 and 4 taken in ord-er to the right of Fig. 1, illustrate so much of a telephone exchange system as is necessary to an understanding of the invention,

Fig. l shows a subscribers line incoming to an operators position in a manual Ollio-e and an operators connecting circuit for eX- tending the subscriber-s line to a trunlr outgoing to a distant office. This figure also illustrates diagrammatically a plurality of registers which are arranged to be manually set by the operator for recording the designations of subscribers lines. p

Fig. 2 shows a central office sender comprising a series of counting relays for controlling the automatic switches in a distant ollice. n

Fig. 8 shows an incoming selector switch in a distant automatic office, which is reached by the trunk line leading` from the operators position in the manual office.

Fig. l shows a final selector switch which serves to further extend the incoming connections to the desired lines.

Fig. 5 is a front view showing the structure and mechanical details of the operators register set. Certain parts of the structure have been broken away in order to expose the interior, while other parts are shown in section, such s-ection being taken alongthe line 5 5 of Fig. 6.

Fig. 6 is a side view of the register set with certain parts removed in order to reveal the interior arrangement.

The automatic switches shown in Figs. 3 and 4 are of the well-known power driven type and may be in general of the same structure as the switch shown and described in detail in the patent to Craft & Reynolds No. 1,123,696, issued January 5, 1915.

Referring to Figs. 5 and 6, a description will first be given of the construction of the operators-register set before attempting to explain the circuit functions it performs in controlling the automat c switches. Ilhe housing portion of this device consists of two rectangular

metallic plates

500 and 501, disposed at right-angles to one another and secured in any suitable manner. To further enclose the space provided by the

plates

500 and 501, a cylindrical-shaped casing 503 .s usedas shown in Fig. 6 and may be suitably attached to

members

500 and 501. Within theenclosure and disposed parallel to the baseplate 500,` is a bearing rod 502. Tthe rod 502r extends throughout the entire length ofthe plate 500 and may be supported in any convenient manner, as for example in near ngs, not shown, carried by the opposite ends of the casing 503.

Four sector-shaped

registers

505, 506, 507 and 508 are rotatably mounted onthe rod Each of these register members such as register 508 shown in Fig. 6, is provided with an arcuate portion which carries pro` `iections 509. In the spaces between adjacent projections 509, a series of dentifying characters are inscribedsuch as the ten ordinals. With the registers in their normal position as shown in Fig. 6, the vertical portion ofthe member 508 bears aga nst a stop 529. In this position the arcuate portion of member 508 is disposed in full view of the operator by means of a rectangular opening cutin the casing 503. Observing in particular F g. 45, it is noted that each cf the four different registers is provided with an individual window or slot in the casing 503. The projections 509 serve as finger-holds Awhereby the operator may rotate the sector register in a counter-clockwise d rection through a distance equivalent to any particular digit which she may desire to record. The lower extremity of the slot, through which the finger is inserted, serves as a stop to accurately determine the extent of the movement through which the register isrotated.

The four different register members are each provided with contact making brushes. {egister 505 carries two brushes 511 and ed of insulating material.

512. itegister 506 carries three

brushes

513, 514 and 515. Each of the

registers

507 and 508 is equipped with a single brush 5l6and 51T, respectively. Looking at Fig. 6, the method of attaching the brushes to the sector-shaped register is clearly illustrated. A- small rectangular bracket 510 is secured to the member 508 by means of screws. The brush 51(- is secured to the bracket 510 and insulated therefrom by suitable material. Similarly, the

brushes

511, 512, 513, 514, 515 and 516 are attached to their, respective register numbers. l/Vhere morethan one brush .s carried bythe same number, vthese brushes, are insulatedfrom one .another as well as beinginsulated from Othermetallicparts of the device.

The contact making brushes just `described are adapted to cooperate, with series of terminals arranged in a circular-shaped bank.l 'lnis bank consists of seven

arcuate blocks

519, 520, 521, 522, 523, 524 and 52,5.constructv Thesev arcuate blocks are assembled and secured t-oeach other by means ofrods 526 and 527 to p rovide the terminal bank, the front of which is best shown in Fig. 5. Byv means of an at` tachingplate 544 and screws535, theaassem.- bled bank is securely mounted on .the base plate 500 as best seen in F ig. 5. the arcuate blocks 519, y520, 521, etc., is. provided with a series of ten radal chan-nels` in which terminal pins suchl as 53.7, 538, 539, 541, 542 and 543 are adaptedto be inserted and secured. These. terminal pins when ixed in place provide an arcuate row yof ten. terminals each, which align withthe brushes 511, 512, 513, 514, etc., inthe rotation .ofthe four register members.y For example, the brush 511,A carried by register member 505 f engages the row of ten terminals ofwhich.

terminal 537 is the third-one.; brush 512cm.: gagesthe `row .of .ten terminals ,of wh chterminal 538 is also the third` onef; ybrush 551.3,

carried by the register member 506, engages the series ofiten. terminals of whichterminal 539 is the fourth and so on.

The terminal pins project through the arcuate insulating

blocks

519, 520, 521, etc.,

as shown in Fig. 6. Connecting wires. are

soldered to the projecting endsof the'termi-y nal pins and extend tol thedistributing block 528 secured to the casinga-t the left-hand side of the device. The wires leadingto the brushes carried by theregisters are also c onnected to the distributingblock 528 as show-n in Fig. 6. From the distributing blockthe several conductors com-mg from` theterm-inal bank and from the rotatable brushes are.

grouped in the form `of the cable 536, which may be extendedl to yany convenient pointinr ter member, the vertical portion of the member bears agail'ist the longitudinal bar 534. This bar entends longitudinally before all of the four dierent registers and is attached for rotation to the bearing rod 502 as shown in Fig. 6. The rotation of the bar 534 by the rotating register member such as 505 causes the roller 533 to press against the cani surface of the lever 532. This action causes the key 531, which is attached to the opposite end of lever 532, to rotate upwardly in the slot 504 about the pivot 530. `After the four different registers have been adjusted to their proper positions to record the four digits of a called number and the connection has been established and the operator wishes to restore the register device to normal, she simply depresses the restoring key 531 back to its normal position as shown in Fig. 5. By depressing the key 531, the lever 532 is caused to rotate about pin 530 and in turn the longitudinal bar 534 rotates about rod 502, thereby forcing the sector-shaped register members back to their restored positions against the stop 529.

The circuit arrangement shown in Figs. 1, 2, 3 and 4 will now be considered. VVhe-n a call originates on a subscribers line such as line 100, which may terminate directly before the operators positionv in the manual oflice, shown in Fig. 1, or which may be e2:- tended to such position over an intenci'hce trunk line, the operator responds by means of her answering plug (not shown) and the callingline is thus extended to the repeating coil 103. The operator listens 1n and ascertains the wants of the calling subscriber. On learning, for example, that he wishes to obtain connection with a subscribers line, which belongs to a distant automatic otlice, she causes a register sender to be associated with the cord circuit which she has taken for use and also proceeds to record the digits of the wanted number on the register device at herA position. rlhe operator then inserts the other plug of her cord circuit in the jack of a trunk line outgoing to the oiiice in which the called subscribers line terminates. From this point on the extension of the connection forward to the called subscribers line is under the control of the register' sender and requires no further effort on the part of the operator.

Having explained the construction of the operators register mechanism and outlined in general the principle on which calls in a system of this character are handled, a de-` tailed description will now be given of the operations concerned in the extension of a connection from the calling subscribers line to a called subscribers line. For this purpose, assume that the subscriber of line 100, which terminates in the manual office illustrated in Figs. 1 and 2, wishes to converse with the subscriber of line 432, which terminates in the multiple terminals of automatic switches in the distant mechanical office illustrated in Figs. 3 and 4. Upon initiating the call the subscriber at substation causes, in the well-known manner, the illumination of the line lamp before the operator. In respense she inserts the answering plug (not shown) of one of her cord circuits in the jack of the subscriber-s line. her listening lrey 101 and converses with the subscriber. On being informed that he wishes to obtain a connection with a subscribers line in a distant mechanical olice, the operator first manipulates an assignment key 104, the :function of which is to associate the register sender shown in F ig. 2 with the cord circuit which she has chosen for use. The depression of key 104 completes a circuit from ground through the winding of relay 105, key 104, conductor 117, contact and left-hand armature of relay 202, Windu ing of relay 200 to battery and ground. Re-

lays 105 and 200 become energized in this in Fig. 2 was idle and has been associated with her cord circuit.

Next, the operator records on the registers at her position the digits of the called number communicated to her by the calling subscriber. Assume that the called oce has a capacity7 of 10,000 lines and that the number of the desired line is 2345. The operator thereupon adjusts the thousands register 505, the hundreds register 506, the tens register 507 and the units register 508 in accordance with the corresponding digits of the desired number. Since the thousands digits is 2, the

brushes

511 and 512 carried by member 505 are positioned on their No. 2

terminals

537 and 533, respectively. Since the hundreds digit is 3, the

brushesv

513, 514 and 515 of the hundreds register 506 are set on their No. 3 terminals 539, 540and 541, respectively. Likewise for the tens and units registers the

brushes

516 and 517 are positioned on their No. 5 and No. 6

terminals

542 and 543, respectively. Having reg istered the designation of the called line, the operator seizes the plug 111 of her cord circuit and inserts it in the jack 112 `of an idle trunlr line 114.115 outgoing to the desired distant mechanical o'liice. The insertion of the plug 1.11 into the plug-112 completes a circuit from battery through the supervisory lamp 107, resistance 109, con ductor 110, sleeve of plug 111, sleeve of jack 112, winding of relay 113 to ground. The lamp 10T!I is illuminated and relay 113 operates to yconnect the tip and ring sides of the She then depressesr operators cord' circuit to the corresponding conductors of the out-going trunk. At the same time, a circuit is completed from battery through the winding of relay 204, conductor 116, innerl lower armature and contact ofrelay 105, conductor 110, sleeve of plug 111, sleeve of jack 112 to ground through the winding of relay 113. Relay 2011 becomes energized and ycloses the fundamental'circuit from the sender through to the incoming` selector switch at the distant mechanical oflifce. This circuit may be traced from battery through the left-hand winding of relay 301, upper right-hand contact 336 (1), upper left-hand contact 330 (ll-t4), lower right-hand contact 339 (l-l-t), conductor 1l-il, upper armature and contact ofrelay 113, tip of jacll: 112, tip of plug 111, uppermost arn'iature and front con'- tact of'relay 105, conductor 113, armature and contact of relay 204, winding of relay 205, winding of relay 206, ycontact and lefthand armature of relay 20?, contact and armature of'relay 235, conductor 110, front contact and lowermost arn'iature of relay 105, ring of plug 111, ring of jack 112, contact and lower armature of relay 113 conductor 115, upper right-hand contact 311-0 (1d-3) to ground. Relay 301 and the stepping relay 205 becomes energized in the fundamental circuit, but relay 206 being polarized does not operate in View of the fact that current flows `in the wrong direction. Relay 301 completes acircuit from ground through its "outer armature and front Contact, lower contact' 32S, (1), winding of sequence switch magnet 300-'to battery and ground. Sequence 300' advances from position 1 into position 2. In this position the relay 301 remains energized lin a' circuit from battery through its left-hand winding and front contact and inner armature, lower righthand and upper left-hand contacts 336 (1d-1) to ground over the fundamental circuit as above traced. With the sequence switch 300 in position 2 and relay 301 energized, a circuit is completed for the updrive iower magnet 307 traceable as follows:

battery through the winding of magnet 307, upper contact 323 to ground at the front contact and outer armature of relay 301.E The. magnet 307 energizes and causes thel brush shaft 341 to be driven upwardly in the well-known manner.

Then the stepping relay 205 becomes energized in the fundamental circuit, it completes a circuit from ground through its contactv and armature, conductor 237, righthand armature and back contacts of

relays

214, 212, 210 and 208 in series, conductor 216, brush 511 of the thousands register, terminal 537, conductor 221, armature and bacl contactof counting relay 227, winding of relay 226 to battery and ground. Relay'226becomes energized and closes a series circuit from battery through its winding@ and the winding of relay-227, contact and armature of relay 226 to `ground at the contact and right-hand armature of relay 207. Relay 227, however, does not'energize at this time, since its winding'isshunted out'by the direct circuit to ground at the armature andk lcontact of the stepping relay 205. As the brush shaft reaches the first tripping position, brush 321 encountersthelirst metallic segment of commutator 322. A* circuit is thenclosed from battery through the lefthand windingfand front contact and inner armaturev` of relay 301, lower right-hand contact 336'` (1A-4), lower left-hand contact 330 (Kyla-P2), commutator 322, brush 321 to ground'. Relay 321 remains energized in this circuit while the Stepping'relay 205 in the fundamental circuit is shunted out and releases its armature. The shuntcircuit is now removed from aroundl the winding of relay 227 and this relay becomes energized in series with relay 226. When brush 321 disengages the firstv metallic segment' of commutator 322, the shunt isremoved from the winding of relay 205iand this relay again attracts its armature;l The stepping circuit is now extendedby way ofvconductor 221, armature andffront` contact of relay 227, inner right-hand armature yand back contact of relay 233, winding'of relay 234 to battery and ground. Relay 234s attracts its armature' and completes a circuit from battery througlr thawindin'g'of said relay, baclr contact and inner right`hand armature of relay 238through the'windings of

relays

236 and 235"in-paralli-zl,l outer right-hand armature and back: contact of` relay' 238, contact and armature'of'relay 23ste ground at'the right-hand"armature of relay 207. Relays 236 and` 235 remain deenergiz'ed since their windingsareishuntedfout by' thev direct circuit tol ground at 'the stepping relay 205. Ass'oonasthfelnext brushk trip`- ping position is'rea'ched yloythe'brnsh shaft 341, stepping relay 205 deenergizes and re# lays 236 and235` lockv up4 in 'series with thev counting'relay 2341. Relay 235 opens thev fundamental circuit. Relay'236 at its left-` hand armature closes a circuit 'forfrelay 20'?. Relay207 isconstructed so asto attract its armatures slowly after'its'energizing circuit is completed and also to release its armatures slowlyafter the circuity is opened. Relay 236 also completes'a circuit' fromv ground through its right-hand armature and contact, armatureland back' contact of relay 209, winding of're'lay 208 to battery and ground.v Relay 208energizes and completes a circuit throughits winding and the winding of relay 209 in series, contact and left-hand armature of relay 208, conductor 239 to ground atthe right-hand armature and contact of relay 202.A Relay209, how# ever, is not energized'at this'time,'sinceiits winding is shunted out by the circuit above traced lto ground at the right-hand armature of relay 236. After the necessary time has elapsed following the energization of relay 236, the slow operating relay 207 attracts its armatures and opens the locking circuits of all counting relays. Relay 235 deenergizes and again closes the fundamental circuits at its armature and contact. Relay 236 releases its armatures and opens the shunt around the winding of ,relay 209,

whereby this relay energizes and locks up in series with relay 208. Relay 236 also Iopens the circuit of relay 207 which commences to deenergize. During the time relay 207 is operated the fundamental circuit is held open at the left-hand armature and contact of said relay.

As soon, after the opening of the fundamental circuit at the armature of relay 235, as the brush 321 engages the next insulating segment of commutator 322, relay 301 becomes deenergized. A circuit is then completed lfrom ground through the outer armature and back contact of relay 301, upper right-hand contact 325 (2), winding of sequence switch magnet 300 to battery and ground, driving switch 300 out of position 2and into position 3. Relay 301 on releasing also opens the circuit of the updrive power magnet 307, whereby the switch shaft 341 ceases its upward movement. With sequence switch 300 in position 3, the tripping magnet 309 is energized in a circuit including contact 335 (3d-4). The magnet 309 rotates the trip spindle preparatory to tripping the selected set of brushes upon the next upward movement of the shaft 341.

After relay 207 becomes deenergized, and provided sequence switch 300 has reached position 3, the fundamental circuit is again completed and relay 301 energizes in series with the stepping relay 205. Relay 301 completes a circuit from ground through its outer armature and front contact, lower contact 323 (3), winding of sequence switch magnet 300 to battery and ground. Sequence switch 300 advances into position 4 and relay 301 remains energized in a circuit through its left-hand winding and front contact and inner armature, lower righthand and upper left-hand contacts 336 (1 -t4), thence to ground as above described over the fundamental circuit. Relay 301 i again closes the circuit for the updrive power magnet 307, this time in position 4 of sequence switch contact 323. Magnet 30%7 energizes and the brush shaft 341 is driven upwardly to select the proper group oftrunk terminals.

The stepping relay 205, energizing in the fundamental circuit, closes a circuit from ground through its contact and armature, conductor 237, righbhand armatures and back contacts of

relays

21,4, 212 and 210 in series, right-hand armature and front contact of relay 203, conductor 217, brush 512 of the thousands register, terminal 538, brush of the hundreds register, terminal 539, conductor 222, relay 234 to battery and ground. Relay 234 operates andprepares a holding circuit for itself in series with the windings of

relays

236 and 235. These latter relays, however, do not energize so long as stepping relay 205 maintains its armature attracted.

As soon as the selected set of

brushes

310, 311 and 312 reach the lirst group of terminals, the brush 320 engages a metallic segment of commutator 323. A circuit is thereby closedjfrom battery through vthe left-hand winding andy front contact and inner armature of relay 301, contact 326 3%-l-4), commutator 323, brush 320 to ground. r1`his circuit causes the stepping relay 205 to be shunted. Relay 205 upon releasing its armature, opens the short-circuit around the windings of

relays

236 and 235 and these relays lock up in series with relay 234. Relay 235 opens the fundamental circuit while relay 236 at its left-hand armature closes the energizing circuit of slow operating' relay 207. Relay 236 at its righthand armature completes a circuit from ground through the armature and front contact of relay 209, armature and back contact of relay 211, winding of relay 210 to battery and ground. `Relay 210 attracts its armatures and closes a series circuit for itself and the winding of relay 211 to ground at the right-hand armature and Contact of relay 202. Relay 211, however, does not energize due to the shunt circuit closed at the right-hand armature of relay 236. After an interval, relay 207 attracts its armatures and opens the locking circuits of thev counting relays. Relay 236 opens the circuit of relay 207 and at its right-hand armature removes the shunt from around the winding of relay 211. Relay 211 now actuates and locks up to the grounded conductor 239 in series with relay 210. When the brush 320 engages the next insulating segment of commutator 323 following the opening of the fundamental circuit at the sender, relay 301 deenergizes and opensthe circuit of the updrive power magnet 307. The

brushes

310, 311 and 312, therefore, come to rest in operative relation to the selected group of terminals. n Relay 301 also closes a circuit from ground through its upper armature and back contact, upper right-hand contact 325 4), winding-of sequence switch magnet 300 to kbattery and ground. Sequence switch 300 is driven out of position 4 and into position 5. y V

Immediately that sequence switch 300 reaches position 5, a circuit is closedl from battery through the right-hand winding of relay 301, contact 327 (5-}-51/4) to ground.

winding of i Relay 301 operates and completes a circuit from ground through its outer armature and iront contact, lower contact 32S (5), winding of sequence switch nagnet 300 to battery and Lground, driving said sequence switch out oi position 5 and into position 6. Y

`When sequence switch 300 leaves position 51/4,the originalenergizing circuit of relay 301 is opened at contact 327. This relay, however, remains locked up, provided the first trunlrin the selected group is busy. The holding circuit or relay 301 may be traced from battery through the lett-hand winding and front Contact and inner armature o' said relay, lower left-hand Contact 331 (5d-6), upper rightehand contact 331 (5dr-15), brush 812 to the grounded test terminal 315 of the busy trunlr. Relay 2301 by ren'iaining4 energized closes a circuit trom ground through itsouter armature and' trout contact, upper contact'328 winding ot' the updrive power magnet 307 to battery and ground. The

brushes

310, 311, and 312 are thus driven upwardly over the group of trunks in search ot an idle one; iissoonas the tirst idle trunk is encountered, the test brushA 312 fails to find a yground potential on-the test terminalthereof and the circuit of relay 301 is severed. This relay releases its armatures and opens the circuit of the updrive power magnet 307, causing the brushes to come to rest at the terminals ot the idle trunk. Relay S01 also closesa circuit fromY ground through its outer arma*- ture and back contact, upper right-hand Contact 325 (6) through the windingI of sequence switch 300 to battery and ground, moving said sequence switch out or" position G and into position 7. As sequence switch 300 reaches position 6%, the selected trunk is rendered busy by means of ground potential being applied to the test terminal 31.5 over the following path: ground, through the lower right-hand contact 881 (egli-H5) upper right-hand contact 331 (5-l-15), brush 312 to the test terminal 41'circuit is now closed from battery through the left-hand winding of relay 301, upper Contact 329 (7), lower contact. 334 (Pf-P8), brush 311, terminal 314, conductor 317, upper left-hand contact 414 (15l-10) of sequence switch 400, ylower right-hand Contact 414 (l-ll/g) ,contact 430 (1li-8%.) to ground. Relay 301 becomes energized and looks up in a circuit from battery throughl its lett-hand winding;- and front contact and inner armature, contact (T+S), thence to. ground, as described at Contact 430. Relay 301 by attracting its outer armature completes a 4circuit from ground through lower Contact 328 (7) through the winding: of sequence switch tobattery and ground. Sequence switch 3004 is thereupon driven out oit position. 7

into position 8.

rllhe fundamental circuit isnow extended from the senderthrough to the final selector switch shown in Fig.l 4. This circuit may be traced from battery through the lefthand winding o't' relay 401, lower lett-hand Contact 433 (1), lower lett-handl contact413 (15d-6), conductor 316, brush 310, upper lett-hand Contact 339 v(53), conductor 114, thence as described through the stepping relay 205 and returning by way ot conductor 115 to ground at' the upper contact S40 (1-1-8). Relay 401 becomes energized in series withthe stepping relay 205. Relay 401 closes a circuit from ground through its outer left-hand armature and `front con tact, lower contact 408 (1), winding oll sequence switch magnet 400 to battery and ground. Sequence switch 400 moyesout ot position 1 andinto-position 2. Relay 40.1 remains locked up, in position-2 of sequence switch 400by meansof the circuit from hat tery through` the left-hand winding and contact andy inner lett-hand armature ot relay 401', contact 409 (154-10), lower right'- hand contact 433 (1-l-6) and thence to ground asf'describedabove. Relay 401 closes a circuit tollowsfor the updriye power magnet 403; battery, through the winding; otsaidmagnet, upper contact 408 (2)' trout contact andfouter lett-hand armature ot relay 401 toground. Mangue-t 403 causes the upward movement of thel brush shaft 431 for the purposeof selecting the proper set ot brushes.

Relay 205 upon energizing in the tundrmental circuit closes a circuit troni grouil through its Contact and armature. conductor 237, right-hand armature and back contact of relay right-hand armature and haelt contact of relay 212` right-hand armature and front contact oi relay 210, conductor 218, brush 515 of' the hundredsy register ten minal 541` conductor '223, armature and haelt contact ott relay winding of relay 2, w to battery and ground. Relay 228 attracts its armature and prepares av circuit 'for itself in' series-with the winding of relay Relay'229 does not become'energriaed since it is shuntedout by the stepping' relay 205 as above explained'.

For each brush trippin position throiuh which the brush shaft 431 is driven; the brush 425.r encounters a metallic segment of the cominutator 426. A circuit is thereby closed from batterythrough the lett-hand winding and Contact and inner left-hand armature ot; relay 401, Contact 400 (15}-10)` lower right-handy Contact (1-1-5) upper right-hand contact 413 (13/4-l-2). commutator 426, brush 425 togrround1 Each time this circuit is closed. the stepping; relay 205 is shunted and anV additional pair of countina' relaysv are energized aud loclred up. llVheu Finally the last counting relaysg and 235 arerenergi-zed, the fundamental cirrelay 207 is completed.

cuit is opened and the energizing circuit of Furtheri'nore, relay 236 at its right-hand armature closes the circuit from ground through the armature and front contact of relay 209, arn1iature and front contact of relay 211, armature and back contact of relay 213, winding of relay 212 to battery and ground. Relay 212 becomes energized and closes a circuit for itself in series with the winding of relay 213, contact and left-hand armature of relay 212 to ground at the righthand armature and Contact of relay 202. Relay 213 does not become energized as its winding is short-circuited by the relay 236. Relay 207 energizes after an inte val and the counting relays are released. Relay 236 in turn opens the energizing circuit of relay 207 and also removes the shunt from around the winding of relay 213. rlhis latter relay now becomes energized in series with relay 212.

As soon, following the opening of the fundamental circuit at the armature and Contact of relay 235, as the brush 425 engages the next insulating segment of commutator V426, the circuit of relay 401 is opened and said relay deenergizes. Relay 401 opens the circuit of the updrive power magnet 403 causing the brush shaft 431 to stop' and also completes a circuit from ground through its outer left-hand armature and back contact, upper left-hand contact 407 (2), through the winding of sequence switch 400 to battery and ground. Sequence switch 400 advances from position 2 into position 3. In position 3, tripping magnet 405 is energized in a circuit including the contact 412 (3+4). Magnet 405 rotates the trip spindle to a position where'it will be effective in tripping the selectedpset of brushes on the next upward movement of the shaft 431.

With the sequence switch 400 in position 3 and relay 207 deenergized., the fundamental circuit is closed for controlling the tens selective movement of the switch. rlhe fundamental circuit in this `case is the same as in the circuit heretofore traced with the exception that sequence switch 400 is standing in position 3 instead of position 1. Relay 401 becomes energized and closes a circuit from ground through its outer lefthandv armature and front contact and lower contact 408 (3) for driving sequence` switch 400 into position 4. In this position, relay 401 remains energized in a locking circuit from battery through its left-hand winding and contact and inner left-hand armature, contact 409 (15-l-10) and thence over the fundamental circuit as heretofore traced. Relay 401 also recloses the circuit for lthe updrive power magnet 403 and the brush shaft 431 is driven upwardly to select the proper group of ten terminals.

Stepping relay 205 at the sender upon energizing, closes a circuit from ground through its contact and armature, conductor 237, right-hand armature and back contact of relay 214, right-hand armature and front `contact of relay 212, conductor 219, brush 516 of the tens register, terminal conductor 224, armature and back contact of counting relay 231, Winding of relay 230 to battery and ground. Relay 230 energizes and prepares a circuit for itself and relay 231. Each time the

brushes

413, 419 and 420 pass over a group of ten terminals.

the brush 424 engages a metallic segment of commutator 423 and the following cir-` cuit is closed to shunt the stepping rela;Y 205 in the fundamental circuit: battery, through the left-hand winding and Contact and inner left-hand armature of relay 401,- contact 409 (154-10), lower right-hand contact 433 (141-6), upper right-hand contact 433 (3%-l-4), connnutator 423, brush 424 to ground. For each deenergization of stepping relay 205, a pair of counting relays are energized and locked up until finally the counting' relays and 236 are operated. Relay opens the fundamental circuit and relay 236 causes the deenergization of relay 227. Relay 236 also closes a circuit from ground through its right-hand armature and contact, armature and front contact ot' relay 209, armature and front Contact of relay 211, armature and front contact of relay 213, armature and back conta-ct of relay 215, winding of relay 214 to battery and ground. Relay 214 energizcs and plicpares a circuit for itself and the winding of relay 215. After an interval, rela-y 207 attracts its armature yand opens the loci;-v

ing circuit of the energized counting relays. Relay 236 in turn opens the energizing circuit of relay 207, which commences to deenergize. Relay 236 at its right-hand narmature removes the shunt from around the winding of relay 215 and this latter relay locks up in series with relay 214.

After the fundamental circuit has been opened at the sender and brush 424 engages the next insulating segment of coinniutator 423, the circuit of relay k401 is opened. Relay 401 thereupon deenergizes and opens the `circuit of the updrive power` magnet 403. Relay 401 also completes a `circuit. from ground through its outer left-hand armature andV haelt Contact, upper left-hand Contact 407 (4), through the winding of sequence switch magnet 400 to battery. and ground. Sequence switch 400 moves out of position 4 and into position 5. y

As soon as the slow operating relay 207 retracts its armatures, the fundamental circuit is again closed and relay 401 energizes -switch 400 out of position and into po tact closes a circuit for driving sequence tion`6. 1n this position relay 401 rer-i. ...s locked up in the circuit above traced. Relay 402 is energized at this time in a circuit from battery through the winding of said relay, contact 415 (134-17) conductor 318, terminal 315, brush 312, upper righthand contact 331 (5-l-15), lower right-hand contact 331 (6%-1-15) to ground. Relay 401 also completes a circuit `from battery through the winding of the. updrire power magnet 403, upper contact 403 (6) tor ground at the front contact and outerI leftA hand armature of relay 401. Magnet 403 energizes and the brushes 413, Ll1 ,a and 420 are driven over the group of ten ter ninals to select the terminals of the called subscribers line.

The stepping relay 205 completes a circuit from ground through its contact and armature, conductor 237, right-hand armature and front contact of relay 214, conductor 220, brush 517, terminal 543, conductor 225, armature and baci; Contact of relay 233, winding` of relay 232 to battery and ground. Relay 232 becomes energized and prepares a circuit for itseltl in series with the winding of relay 233. For each set of terminals passed over by the brushes 41S. 419 and 420, the brush 425 engages a metallic segment of commutator 427 and the following circuit is established to shunt the stepping relay 205 in the Yfundamental circuit: battery, through the left-hand wind ing and contact and inner left-hand armature of relay 401, contact 409 (-1-10), lower right-hand contact 433 14-6), upper right-hand contact 413 (+6), commutator 427 brush 425 to ground. Each time the stepping relay 205 deenergizes, a pair of counting relays are energized and locked up. When finally, the

relays

236 and 235 are operated, the fundamental circuit is opened and the circuit of relay T is completed. Relay 236 also establishes a circuit from ground through its right-hand armature and Contact, armatures and front contacts of

relays

209, 211, 213 and 215 in series, winding of relay 203 to battery and ground. Relay 203 cnergizes before the relay 207 has time to attract its armatures. The energized counting relays are, therefore, held operated in a circuit closed to ground at the contact and left-hand armature of relay 203. Relay v203 also at its right-hand armature completes acircuit for relay 202. Relay 202 which is slow to attract its armatures operates after the lapse of a time interval and removes ground from the conductor 239.

,215 opens the series energizing circuit for relay `203, VRelay 203 deenergizes and opens the holding circuit of the counting relays. Relay 236 upon deenergizing opens the holding circuit of relay 20T, which, after an interval of time, releases its armatures. .dit the time relay 202 attracts its armatures, the circuit of

relays

200 and 105 is opened. ReH lay 200 deenergiaes and causes the lamp 201 to be retired. Relay 105 also deenerfriu-fs and disconnects the fundamental circuit from -the tip and ringconductors of the

outgoing trunk

114 and 115 and extends said trunl; through to the right-hand windings of the repeating` coil 103 in the operators cord circuit.

A s soon. after the fundamental circuit is opened at the sender, as the

brushes

418, 419 and 420 are accurately centered on

terminals

421, 422 and 423 of the called subscribers line, the brush 425 engages an insulating` segment of commutator 42'?. Relay 401 is therefore deenergized and opens the circuit of tie updriye power magnet 403. Relay 401, furthermore, closes a circuit including its outer left-hand armature and baclr contact and upper left-hand contact 407 (6) for driving sequence switch 400 out of position 6 and into position 16. A test of the condition of the called subscriber-s line is made while sequence switch 400 is passing through position 12. Assume in this case that the called subscribers line is idle when the test is made. rllhe test circuit may be traced from battery, through the righthand winding of relay 401, upper left-hand Contact 411 (12), upper right-hand contact 411 (12-{-16). test 1crush 420 to the test terminal 423. Since the line is idle at this time no ground potential exists at terminal 423 and consequently, the relay 401 remains inactive. Sequence switch 400, therefore, comes to rest in position 16 which is the talking position.

As sequence switch 400 moves out of position 81/2, its

contacts

414 and 430 are opened and the heretofore traced circuit of relay 301 is severed. Relay 301 becomes deenergized and completes a circuit to ground, through its outer armature and baci; contact, upper right-hand contact 324 (8), winding of sequence switch 300 to battery and ground. Sequence switch 300 moves out of position 8 and into position 15, which is the ringing and talking position for this sequence switch. ln position 15 a circuit is closed from battery through the winding of relay 304, armature and back contact of relay 306, armature and contact of relay V305, contact 332 (15) to ground. A circuit is also closed from battery, througi the windings of

relays

304 and 306 in seriestoground at the contact 332. Relay 304 becomes energized. but relay '306 remains inert since its winding is shunted out by the circuit traced through the armature and contact of relay 305. Relay 304 closes a circuit from the source of ringing current 342, through the winding of relay 305, front contact and lower armature of relay 304, upper contact v 334 (154-16), brush 311, terminal 314, conductor 317, upper left-hand contact 414 (15-I-10), upper right-hand contact 114 (16), brush 419, terminal 422 over the loop of the called subscribers line, terminal 421,

Abrush 418, lower right-hand contact 413 from battery through its front Contact, and

armature and winding to ground ai. contact 332. This circuit shunts out the relay 304 and permits the same to release its armatures. Relay 304 opens the ringing circuitand closes the trunk conductors 31C and 317 through to the right-hand windings of the repeating coil 319. Since the called subscribers receiver is off the switch-hook, a circuit is now completed from battery, through the lower right-hand winding of repeating coil 319, winding of relay 303, thence over the ring side of the line, through the loop of the called substation and returning over the vtip side of the line through the upper right-hand winding of repeating coil 319 to ground.

Returning to the point where sequence switch 300 is driven from position 8 to 15, it will bek noted that as said sequencek switch arrives in position 14, a circuit is closed from battery, through the left-hand winding of relay 302, contact 338 (14-1-15), through the upper left-hand winding of repeating coil 319, upper right-hand contact 339 (14-1-16), conductor 114, upper arma.` ture and contact of relay 113, tipv of jack 112, tip of plug 111, uppermost armature and Contact of relay 105, upper right-hand winding of repeating coil 103 to ground.

-Relay 302 becomes energized through its left-hand winding. When sequence switch 300 reaches position 15, the following circuit is closed for the right-hand winding of said relay: battery, through the lower righthand windingfof repeating coil103, winding of supervisory relay 106, back contact and lowermost armature of relay 105, ring of plug 111, ring of jack 112, contact and lower armature of relay 113, conductor 115, lower contact 340 (14-l-16), lower left-hand winding of repeating coil 319, `resistance 343,

upper contact 337 (15'), right-hand winding of relay 302 to ground. Due to the high resistance 343 sufficient current does not flow in this circuit to permit the energization of relay 106. When, as explained, the called subscriber removes his receiver from the switchhookin response to the ringing of his substation bell, relay 303 becomes energized, a short-circuit is closed'around the high resistance 343. The resistance 343 being thus removed from the circuit of relay 106, this relay attracts its armature Aand closes a circuit as follows to shunt out the supervisory lamp 107: battery through the contact of said relay,y resistances 108 land 109, conductor 110 to vground'through the winding of relay 113; rlhe extinguishment of lamp 107 notifies the operator in the manual olice that the called subscriber has responded.

After conversation has been completed, the called subscriber by replacing the receiver to the switchhook permits the` deenergization of relay 303, which opens the shunt around resistance 343 and relay 106 in the operators cord circuit again deenergizes. The lamp 107 now becomes illuminated and the operator knows that the called subscriber has hung up his receiver.v In order to disconnect, she removes the plug 111 from jack 112 of the trunk circuit. The removal of the plug from the jack, opens the above traced circuit of relay 302. Relay 302 becomes deenergized and completes a circuit from ground through its armature and contact, upper left-hand contact 325 (154-17), through the winding of sequence switch300 to battery and ground.k Sequence switch 300 moves out of position 15 and kinto position 18. 1n this position a circuit is completed-forthe downdrive power magnet 308, including sequence switch contact 334 (18). The brush shaft 341 is restoredto normal in the well-known manner and'at which time a circuit is closed frombattery through the winding of sequence switch`300, lower left-hand contact 325, normal segment 324, brush 320 to ground. Sequence switch 300 advances into position 1.

As sequence switch 300 moves out of position 15, it opens atits right-hand contacts 331, the holding circuit of relay 402. Relay 402 deenergizes and completes a circuit to ground, through its armature and contact, lower left-hand contact 407 (6%-1-17), winding of sequence switch 400 to battery and ground. Sequence switch 400 moves out of position 16 and into position 18.` In this position a circuit is closed including contact-416 (18) for the downdrive power magnet 404. Magnet 404 causes the restoration ofthe brush shaft 401. When said shaft reaches its normal position, a circuit is completed from battery through the winding of sequence switch magnet 400, lower rio right-hand contact 407 (18), normal segment 429, brush 424 to ground. Sequence switch 400 thereupon advances out ott position 18 and into position 1.

It will next be considered that the called subscribers line 482 is busy at the time thc sequence switch 400 of the i'inal selector `When sequence switch 400 reaches

position

1,6, it continues to advance into position 17 by means of the following circuit: battery, through the winding ot said sequence switch, lower contact 408 (16), front contact and outer left-hand armature ot relay 401 to ground. Since sequence switch 400 i s now in position 17, ringing current is withheld from the subscribers line by eason of the it'act that the circuit leading to the brushes 418 and 41,9 is opened at

contacts

413 and 414. With sequence switch 400 in position 17, the tip and ring conductors 815 and 817 are extended over contact 484 and 485 to the interrupter 417. At the first closure of this interrupter, the relay 805 is energized and ringing` current is disconnected `tsom the. trunk in the manner above described. After the deenergization of relay 804, the interrupter 417 causes the successive energization and deenergization of relay 808. Relay 808 by closing and opening the shunt circuit around resistance 848 causes the supervisory relay 106 in the operators cord circuit to become successively energized and deenergized. The flash of lamp 107 advises the operator that the called line is busy.A She communicatesthis information to the calling subscriber and proceeds to disestablish the connection by removing plug 111 from the trunk jack 112. rlhe incoming selector switch shown in Fig. 8 is restored to normal as heretofore described. When the test conductor 818 is opened, relay 402 releases its .armature and sequence switch 400 at the tinal selector moves from position 16 to 18. 1n this position, the brush shaft is returned to normal and the sequence switch 400 is thereupon restored to position 1.

llfhat is claimed is:

1. In a telephone exchangel system, an automatic switch, a connecting circuit, means for extending a connection over said circuit to the automatic switch, a register controlling mechanism including a plurality ot rotatable registers, manually operable means for adjusting said registers to their set positions, means for associating said mechanism with the connecting circuit, an impulse counting device operable in accordance with the set positions ot said registers,

and means controlled by said counting device for determining the operation ot said automatic switch.

ln a telephone exchange system, a plurality of automatic switches, a trunk circuit, means for extending a connection over said trunk to the automatic switches, a register controlling mechanism including a plurality ot rotatable registers, manually operable means tor adjusting said registers to their set positions, means for associating said mechanism with the connecting circuit, an impulse counting` device controlled in accordance with the` set positions of said registers and while the registers are in such positions, and means controlled by said counting device tor determining vthe operation ot said automatic switches.

In a telephone exchange system, a plurality of automatic switches, a trunk circuit, means for extending a connection over said trunk to theautomatic switches, a register controlling mechanism including a plurality oit rotatable registers arranged to be adjusted manually to their set positions, means Jfor associating said mechanism with the connecting circuit, an impulse counting device controlled in accordance with the set positions et said registers and while the registers are in such positions, means controlled by said counting device for determining the operation oit said automatic switches, and manual means for simultaneously restoring said registers to their normal positions.

4. ln a telephone exchange system, automatic switches, a trunk circuit, means for extending a connectiony over said trunk to the automatic switches, a register controlling mechanism including a plurality of rotatable registers, manually operable means for adjusting said registers to their set positions, means for associating said mechanism with the trunk circuit, a series of counting relays operable in accordance with Vthe set positions of said registers and while the registers are in such positions, and means controlled by said counting relays for determining the op'- eration off the automatic switches.

5. ln a telephone exchange system, automatic switches, a trunk circuit, mean'sfor extending a connection over said trunk to the automatic switches, a plurality ot registers comprising series of stationary terminals, each series disposedon the arc ota circle, brushes for said registers, manually operable means tor rotating each 'of said registers to engage said terminals, an'impulse counting mechanism, means for associating ksaid inechl anism with the trunk circuit, and means for variably operating'said mechanism in accordance with the settings of said registers to control the selective'operations oli said automatic switches.

6. In a telephone exchange system, auto-4 matic switches, an operatrs'position, la

ance with the set positions of said registersand while said registers are in such positions, and means controlled by said counting device for determining the operation of the automatic switches.

7. In a telephone exchange system, automatic switches, an operators position, a trunk circuit, means at the operators position for extending a connection over said trunk circuit to the automatic switches, a register controlling mechanism including a plurality of rotatable registers, manually operable means for adjusting said registers to their set positions, a key for associating said mechanism with the trunk circuit, an impulse counting device operable in accordance with the set positions of said registers and while said registers are in such positions, and means controlled by said counting device for determining the operation of the automatic switches.

8. In a telephone exchange system, automatic switches, an operatoris position, a trunk circuit, means at the operators position for extending a connection over said trunk circuit to the automatic switches, a register controlling mechanism including a plurality of rotatable registers arranged to be adjusted manually by the operator to their set positions, a key tor associating said mechanism with the trunk circuit, an impulse counting device operable in accordance with the set positions of said registers and while said registers are in such positions, means controlled by said counting device for determining the operation of said automatic switches, and a manually operable key for simultaneously restoring said registers to their normal positions.

9. ln a telephone exchange system, auto-v matic switches, an operators position, a trunk circuit, a plurality of connecting circuits at the operators position for extending a connection over said trunk circuit to the automatic switches, a register controlling mechanism at said operators position common to all said connecting circuits including a plurality ot rotatable registers arranged to be adjusted manually by the operator to their set positions, a key for associating said mechanism with one of said connecting circuits, a series of counting relays operable in accordance with the set positions of said registers, means controlled by said counting relays for determining the operation of the automatic switches and manual means for simultaneously restoring said registers to their normal position.

ln testimony whereof, I have signed my name to this specification this 1st day of December, 1920.

WILLIAM A. RHODES.