US1714973A

US1714973A - Signaling system

Info

Publication number: US1714973A
Application number: US4533A
Authority: US
Inventors: Thomas U White
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1925-01-24
Filing date: 1925-01-24
Publication date: 1929-05-28
Anticipated expiration: 1946-05-28

Description

' T. U.l zWHITE May 12,48, 1929.l

sIGNALING sYsTEM 'Filedam 24, 1925.

e sheets-'sheet Y1 ATToRmaYl INVENToR Thomas W/N'e..

WITNES May 28, 1929. f

T. u'. WHITE SIGNALING SYSTEM Filed, Jan. 24,. 1925 l INVENTQ Thomas' lj. h//f/' BY Y v ATTORNEY May 28, 1929.A T U, WHITE 1',114.9'73 y SIGNAL-.ING SYSTEM 'i Filed Jan. :24j-1925' s sheets-Shed 5 'May 28, 1929. T. U. 'WHlTE smNALING SYSTEM Filed Jan. 24, 1925 6 sheets-shea v4 I TORNY T. u. WHn-E' May 28, 1929. 1

SIGNALING SYSTEM Filed Jan. 24, l1925 e sheets-sheet 5l T. U. WHITEv SIGNALING SYSTEM May .2s, 1929 Filed-Jan. 24, 1925 6 sheets-.sheet 6 INVENToR Tho/'was )W2/Ve ATTORNEY www* THQ " WITNESSES: MM

THOMAS U. WHITE, OF PITTSBURGH, PENNSYLVANIA,

ASSIGNOB '1 0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION 0F PENNSYLVANIA.

SIGNALING SYSTEM.

Appli-Gatien nleclJanuary 24, 192'5. serial No. 4,533.

My 'invention relates, in general, to signaling and control systems and particularly to systems for supervising and controlling, from a central point, lremotely-disposed electrical apparatus.

One object of my invention is to provide 'improved selecting apparatus and circuits whereby the dispatcher at the central station may select an apparatus'unit lat one of the remotely-disposed stations.

Another object of my invention is to provide an improved code-sending device at the dispatchers oiiice for controlling the' operation of the selecting device at the station. v 'Another object of-my invention is toprovide an improved selecting device at the station for selecting predetermined apparatus units therein.

Another object of my invention is to provide a code-sending device at thel dispatchers office and a -selecting device at the receiving station that will be operative to select a predetermined apparatus unit without operating it if the dispatcher so desires.

Another object of my invention is to provide an improved control device for bringing about the operation of the selected unit.

Another object of my invention is to provide means for indicating to the dispatcher the apparatus unit selected aft-er such selection has taken place and before such unit is operated. V

lA still .further object of my invention is to provide a code-receiving device at the station that may be controlled from the dispatcher-s office to operate the desired unit after it has been selected by the operation of the selecting device at the station. l

There are other objects of the invention which, together with the foregoing, will be described more fully in the -detailed specification that is to follow. l

Referring now to the drawings, compris-v ing Figures l to 6, inclusive, sufficient apparat-us and circuits have been shown, by means ot the usual conventional diagrams, to enable my invention to be readily eX- plained and understood.v

The apparatus and circuits shown in Figs. 1, 5 and 6 are those located at the disspatchers oice, while the apparatus and circuits shown in Figs. 2, 3 and 4 are lthose located at the station 4 In practicing my invention. I provide a.

plurality .of keys at the dispatchers oiiice,

one for each apparatus unit that itis desired ceiving or'selecting switch is provided, as

well as a finder switch'and a code-sending switch. A group of relays is also provided at the substation for controlling the operation of the selected unit. Certain relays are also provided-at the substation for controlling the operation of the desired apparatus units and for initiating the operation of the iinderand code-sending switches.

Briey, the operation of my invention proceeds as follows: When 4the dispatcher desires to operate an apparatusunit at the station, lhe will operate the key associated with this unit.

1n the proper direction. As a result of this operation, the finder switch is operated to find the position of the desired key. The signaling lamps associated with this key are' so operated as to give an indication opposite from the one shown when the key is in normal position.

Upon the completion ofthe'o'peration ofthe finder switch', the code-sending switch begins to operate and a code of impulses is sent to the substation to control the selectl ing or code-receiving switch thereat. The impulse code for-controlling the code-receiving switch .consistsof twenty-five impulses. The selecting operations are determined by pauses in this code of twenty-five' impulses. The position of these pauses is, in turn, controlled by the position of the iinder switch. As a result of the operations of the' codey receiving switch,I certain relays at the sub- 'station are operated to select the desired apparatus unit.,

Whenthe complete code lof twenty-five impulses has been sent out, a circuit is completed for initiating the operation of the-finder switch at thestation, and this finder switch is operated to connect with the apparatus unit that has been selected by the operation of the selecting relays. The code-sending switch at the station control the operation of the code-receiving. switch at the dispatchers oiiice in substanis then operated 'to ilo ` switch at I sponding connected same manner as the code-sending the .oice controls the code-receiving switch at the station. By the operation of the code-receiving switch at the oice, certain signaling devices are selected, correto theapparatu's unit that has been at the station.

When the'code-sending switch atv the statiallyl the- I tion and the code-receiving switch at the disfth position,

l versed will now operate the con- .trol device'to bring about the desired operation of the selected unit at the station. The operation of this control device sets up cer-A tain indications upon the cha-in otcounting relays at the-station, whereupon the desired apparatus unit is operated. As a result of the operation of the apparatus unit at the station,v the finder switch and code-sending switch thereat are operated lto control the code-sending switch at the office to bring about a change in operation of the signaling devices. This .change indicates to the dispatcher the completed operation of the se` lected apparatus unit. The apparatus is ref stored to normal under the control of the `the inder switch F.

dispatcher.

Referring now'more particularly to Fig.` 1, there is shownin the upper left-hand corner a key K. This key is one of a plurality of keys that is operated tocontrol the selection of thedesired apparatus unit .at the station. The ke 1K is an ordinary doublethrow key of 't e lusual type. Associated witheach key, such as keyK, are t'wo relays 104 and 1,05.v for controlling the operation of A monitorlamp 124 is also associated withfeach key. lA common release key K-l is provided for controlling` certainreleasing operations. This key is of the usual. single-throw, non-locking type.-

The control device, shown at 155, coinprises'an ordinary two-wire calling device well known in the automatic telephone art.

yThis 'callingV device is adapted to produce certain interruptions in the control circuit,

as will appear.

The inder switch--F is of the usual type of rotary switch having four wipers 112 to 115, inclusive, each of which isl adapted to engage a contact bank set comprising twenty-ive. bank contacts. These wipers are moved in a forward direction only vulpon the operation of a motor magnet 106. he mein -the patent to .and urelay l17 indicates to the dis- `relays 411 to 41 naling devices 616 to1621, inc

chanical construction ofthe switch is shown Clement No. 1,107,153.

A code-sending switch CD is associated with the inder switch' F. lThis code-sendingswitch Ais of the same'mechanical construction as the finder swltch F., having tour wipers 151 to 154, inclusive, which are adapted to a motor magnet 142, The wipers of th finder .switch vF while'the wipers of the code-sending switch CD have a normal position. RelayslO? to 111, inclusive, are associated with the finder switch F, whilerelays 143 to 7 are associated with the codesending switch CD. These relays control the be advanced by the operation of.

have no normal position, p

150, inclusive, y

sol

operations of these switches in a manner that will be` described.

control device 155.. single-throw, non-locking type.'

In Fig. l2, a connector switch saine mechanical construction as the "finder Relays and relays 215 to 224, inclusive,are associated with the selecting switch 'II and control these operations. Relays' 200 toy 207, inclusive, comprise the group rot counting relays at the station. '4 l In Fig. 3, three multi-contact relays'300 to 302, inclusive, are shown. The-relays 300 and 4301 are a portion of the primary group of selecting relays and are of the usual multi-contact type. Relays 308v to 311, inclusive, are a portion of the secondary group of selecting relays. A set ofrelays, such as 303 to 305, inclusive, elusive', are associated -with eachy circuit breaker, such as the circuit vbreaker C which is one of the apparatus units at the substation and may vperform any desired function thereat. l c l In Fig. 4 is' shown a finder switch F-l switches aresimilar to theffinde'rv switch F and the code-sending switch CD, previously described. Rela s 400 to 404, inclusive, and

inclusiva, control the operation of the finder switch and tlie codesending switch. i

In Fig. 5 is shown a connector or code-reand a code-sending sWitchCD-L These -ceiving switch H-L This switch is similar .to the connector switch H and has associated relays 500 to 51.0, inclusive, for controlling its operation.

Relays 603 comprise a portion of the secondary selecting relay-group at the d'ispatchers oice while the relays-607 tol 609, inclusive, coin prise a portion of the primar selecting relay group at the dispatchersv o ce. 'Relays 600 to 602, inclusive, control'the operation of sigusive.

Havingf= briefly described the apparatus shown in the drawings, I will n ow explain A key K-e is piaci-.a in'circuavwith ulg This keyis o'tthe usual I-I is of thev 208. to l210, inclusive,

. '120 to' 606, 1nclus1ve, of Fig. 6,

' its detailed operation. For this purpose, lit

unit in such direction as to IWill be assumed that the dispatcher desires to close the circuitinterrupter C at the station. In order to bring about the functioning ofthe selecting apparatus, the dispatcher Will operate the key K associated with this cause the springs 102 and 103 to engage their Working contacts. By the operation of the spring 103 into engagement with its Working contact, a circuit is completed that extends from ground by Way of the Working contact of said spring and said spring, conductor 182, relay 600, and resistor622 to battery.

The relay 600 is energized :over this circuit and operates to establish 'a locking .cir-

cuit for itself at armature 611, to open the circuit of the signaling lamp 616 atarmature 610 and to complete the circuit of the signaling lamp 617 at the v`front oontactof this armature. This change .in supervisory signals informs the dispatcher that the apparatus is functioning .tol select the desired apparatus unit.

Another circuit is completed by the operation of the armatureV with its front Contact over. a path that eX- tends from battery by Way of said armature and its front contact, conductor 183, relay 104, and Working contact of spring 102 of key K and said spring to ground. The relay 104 is. energized over this circuit and operates to establish a locking circuit for itself at arma-ture 121, over theabovetraced circuit including armature 610'7 conductor 183, relay 104, front contact and armature 121 and key K-l to ground, and to complete a circuit for the monitoring lamp 124 at armature'123;

When the key K is released, the original circuit o f the relay 600 is opened, as Well as i the original circuit of the relay 104. These relays are not, however, deenergized by reason of their locking circuits. Other' results of the operation of the relay 104 are that at armature a circuit is prepared for the relay 108, and at armature 122 a circuit is completed which may be traced .from ground by Way of said arma-ture and its front contact, stepping magnet 106 of finder switch F, larmature 129 and its backA contact, back contact and armaturey 134, and back contact and armature 131 to battery.

The stepping magnet 106 operates as a buzzer to advance the switch Wipers 112'toA 115, inclusive, into engagement With the bank contact set Which comprises the bank contacts 116 to 119, inclusive. It will be noted that each contact set is individual to a key such as key K. Thus the group of bank c'ontacts `116-119 is individual to key K and upon operation of key K, the switches are stepped to' and brought to a stop at the contact set individual thereto. In the present instance when the switches reach the lirst .tact 116, armature 120 vslovvreleasing relay contact, armature 610 into engagement,

contact, a circuit is completed extending from ground by Way of Wiper 112, bank conand its front contact and relay 108 to battery.

The relay 108 is operated to open the cir- 70 i cult of the stepping magnet 106 at armature 13 to complete a circuit for the relay 109 at the frontcontact of this armature, to complete a circuit forthe monitoring lamp 176 at 'armature 135, from ground through bat- 75 tery, back contact and armature 163, armature 135 and its -front contact, lamp 176 and ground, and to complete a circuit for the 146 over a path that extends from ground by Way of front contact S0 and armature v136, relay 146, and armature. 163 and its back contact to battery.

The 'circuit of the relay 109 extends from battery by Way of armature'131 and its back 134 and its front contactsi relay 109, bankcontact with which the wiper` 151 is -in engagement and said Wiper to ground. The relay 109 is energized to complete a circuitfor the slow-releasing relay 110 at armature 137. The relay 146 is operated to prepare a circuit for the stepping magnet 142 at armature 162.

'The relay 110 is energized to complete a circuit for the slow-releasing relay 111 at armature 138, and to complete a circuit at 9 armature 139 over a path which extends yfrom battery by Way of back contact and armature 163, front contact and armature 139, impulsing relay 145, and armature 136 and its front contact to ground.

The relay 145 is energized to complete an impulsing circuit at armature 161.A This impulsingcircuit maybe traced from ground through the upper Winding of the line relay 215 at the' substation (Fig. 2), conductor 105 179, armature 161 and its front Contact, normally closed springs controlled by armature 175', conductor 180, and lower Winding of line relay 215 to battery.

The slow-releasing relay 111 is energized to open the circuit of the slow-releasing relay 147 at armature 141. The slow-releasing i relay 147 is deen'ergized to complete a circuit at armature 165 which extends from battery by Way of back contact and 'said armature, slow-releasing relay 148, and armature 170 and its back Contact to ground.

The slow-releasing relay 148 is energized to complete a circuit for thejslow=releasing relay 149 at armature 167. l:, 'The slow-releasmg relay 149 is energizedft'o complete a lcircu'it for the stepping magnet 142 at armature'168 over a path extending from ground by Way of armature 169 arid its back contact, front contact and armature 168, front contact and armature 162, stepping magnet 142, armature and its back contact, Wiper 153, bank contact with Which said Wiper is in engagement, and armature and its back contact to battery.

l The steppingl magnet 142 is' energized' over the above circuit and operates to open lthe circuit of the slow-releasing relay 146 and the impulsing relay-145 at armature 163. The slow-releasing relay 146 is deenergized, after a'short interval of time, to open` ping magnet 142 and the

relays

146 and 145 and relay 150 to are now alternately operated until the Wipers 151to 154 inclusive, of the code` sending'sWitch-are brought into engagement With the bank contact set which includes the bank Contact 171.4

As a result of this operation, a circuit is completed which extends from ground by Way of Wiper 115 of finder switch F, bank contact 119,.bank contact 171, Wiper 152, battery. The relay 150 is operated to open the circuit of the stepping l magnet 142 at armature 169, and to openthe Afteranother short tact and armature 162, stepping relay 150 is circuit of the 'slow-releasing relay 148 at armature 170. The operation of thestepping1 magnet 142 is thus interrupted.

T e slow-releasing relay 148 is deenergized lafter a short interval of time to open the circuit of thel slow-releasing relay 149.

interval of time, the slow-releasing relay 149 is deenergize'd Vto complete the circuit of the stepping magnet 142 over a'path that extends from ground by Way of armature 169 andits front contact, back -contact and armature 168, iront con magnet 142, armature 160 and its `back contact, .Wiper 153, bank contact with which said vviperis inengagement, and armature 165, and its back contact to battery.

The stepping magnet 142 is energized to open the circuit of the

relays

145 and 146. `The relay 146 is deenergized to open the circuit of the stepping magnet 142. By the operation of the steppingA magnet 142, the Wipers 151 to 154, inclusive, are brought into engagement With the next set of bank contacts. By this operation, the circuit of the opened, and this relay is deen-l ergized to complete'the circuit of the relay 148 at armature 170 and to open the circuit of the stepping magnet 142 at armature 169'.

The relay 148 is operated to complete the circuit for the relay 149. The relay 149 is energized to reestablish the original operat-V ing circuit of the stepping magnet 142. The stepping-magnet 142 and the

relays

145 and 146 are novsr alternately operated until the Wipers 151. to 154, inclusive, are brought in- `148 have operated,

.-lay 145 at armature to engagement .with 'the sct of bank contacts which includes the bank contact 173.

Another circuit for the relay 150 is now' completed extending lfrom Way of armature 130 and its back contact, Wiper .113, 4bank contact 117, bank contact v173', Wiper'152, and relay 150 to battery. The .relay 150 and he slow-.releasing relays 148 and 149 operate in the same manner as before to bring about a pause in the operation of the stepping magnet 142, during ,Aften the relays 147 and the original circuit for the stepping `magnet 142 is completed by the energization of the slow-releasing relay tained energized.=

149 and the deenergizationof the relayV 150.

The alternate operation of the

relays

145 and 146 of the stepping magnet 142 now continues until the switch Wipers 151 to 154, inclusive, are vbrought into engagement with their twenty-fifth set of bank contacts. By the operation of thewiper 153, the circuit of the` stepping magnet 142 is. opened A'and this magnet ceases to operate. By the operation of the Wi er 151, the circuit of the relay 109 is opene relay 143. y

The relay `109 is deenergized. -As a result of this operation, the armature 137 .is started into vibration and lalternately sends irn pulses to the slow-releasingrelaysj 110' and 111. l

The relay 143- is energized to complete' a circuit ,forthe relay 144 by reason of the fact that, as the dispatcher desires to control the operation of the circuit interrupter -C at the station, the key K-2 will be in-an operated position. The relay 144 is operated 'to complete a circuit for the' slow-releasing relay y177 at armature 176, to open the impulsing circuit comprising thearmature 161 and its front contact atv armature 175, and

the ground by Y and al circuit is completed for the -which interval of time the relay 145is maini to complete a nevir holding circuit for the line relay 215 of the connector H at the front contact of this armature. -The slowreleasing relay 177 is energized to open another point in the circuit of the stepping magnet v142.

The circuit of the operation of a short interval of time, giz'ed to open the circuit of the impulsing re- 139. The relay 111 is to prepare a circuit for the relay is opened by the armature'137 and, after deenergized shortly the stepping magnet 142 of'the finder. switch 140, and to complete the cir- Fat armature cuit of the slow-releasing relay 147 ,atfarmature 141.

The slow-releasing relay 147 is energized to open the circuit of the' slow-releasing relay 148 at armature 165, to prepare one point in the circuit of the stepping magnet 142 at armature 164, and to prepare another point in the circuit of thestepping magnet this relay is deenerf at armature 166. The relay 148 is deenergized to open `the circuit of the slow-releasing relay 149. This relay is also deenergized to open another point in the circuit of the stepping magnet 142 at armature 168. The deenergization ofthe relay 145 is Without particular function by reason of thev fact that the relay 144 is energized, the key'K-2 having been operated into a position opposite to that shown. The above is the manner in which the code is sent by the code-sending apparatus CD to the codeereceiving,v apparatus comprising the connector H at the substation. in controlling the connector H will now be described. y

lVhen the vimpulsi'ng relay 145 at the dispatchers oiiice is irst operated, a circuit is completed for the line relay 215. The line relay 215 is operated to complete a circuit for the stepping magnet -225 at armature 243, and to complete a circuit for the slow-releasing relay 218 at armature 244. The slowreleasing relay 218 is energized'to prepare a circuit for the slow-releasing relay-219 at armature 249, to complete a circuit for the relay 222at armature 250, and to prepare a selecting circuit at armature 251. rlhe stepping magnet 225 is energized to position its pawl ,so that the switch wipers 211'to 214, inclusive, will be'advanced upon the deenergization of the stepping magnet 225.

The relay 222 is energized to complete a V circuit for the slow-releasing relay 223 at armature 258 and to complete a circuit for the slow-releasing relay 224 at armature 259. The relay 223 is energized to open one point in the selecting circuit at armature 260. Thel slow-releasing relay 224 is energized to open another point in the selecting circuitv at a1niature261. All these operations occur'in response to the energi'zation of the line"relay 215. 4

When the relay 145 at the dispatchers ofy lice is deenergized, the circuit of the line relay 215 is openedandthis relay is deenergized'to open the circuit ofthe stepping magnet 225 at armature 243 and to open the circuit of the slow-releasingrelay 218 at armature 244. The stepping' magnet 225 is deenergized to advance the switch wipers 211 to 214, inclusive, into engagement with their second set of bank contacts.

By the operation of the wiper 212, the circuit of the relay 222 is opened and a circuit is completed vfor the slow-releasing re'- lay 223. The relay 222 is deenergized to open the circuit of the slow-releasing relay 223 and also the circuit of the slow-releasing relay 224.

By the operation of thev Wiper 214, a circuit is completed which extends from ground by way of said wiper, bank contact with which said wiper is 'in engagement, armature 249 and its front contact, and slow-releasing The operation of this code relay 219 to battery. The slow-releasing relay 219 is energized to open one point in the operating circuit at armature 253, and to prepare a circuit for itself at armature 252, exclusive of the armature 249 and its front contact on the relay 218.

The operation or' the vWiper 213 causes the completion of a circuit for the slow-releasing relay 221. The slow-releasing relay 221 is energized to prepare a locking circuit for the relay 220 at armature .256, and to place grpund upon the conductor 27 9 at armature 25 vWhen the circuit of the line relay 215 is again'closed by the operation of the impulsing relay at the dispatchers office, the circuit 'or' the stepping magnet 225 is again com-l pleted, as Vs the circuit of the slow-releasing relay 218. VThe slow-releasing relay 218 has suliicient time lag to prevent its deenergization between successive operations of the 'armature 244 of the line relay 215. The

operation of the stepping magnet 225 now serves to again position the pawl.

The operation of the impulsing relay again opens the circuit of the line relay 215,-where upon the circuit of the stepping magnet 225 is opened tocause this magnet vto advance theswitch wipers 211 to 214, inclusive, into engagement with the next set of bank con- 9 tacts, including the bank Contact 263. The

movement of the switch wip/er 212 opens. the l circuit of the slow-releasing relay 223 `and completes-a circuit for the slow-releasing relay 224. So long as the switch wiper 212 is advanced without interruption, l the

relays

223 and 224 are maintained energized by reason of their sluggish action.

'It will be remembered. that, after the switch wipers of the code-sending switch CD' have' been advanced two steps, a time interval occurs in the operation of the impulsing relay with the consequence that the line relay 215 is maintained energized for a comparatively long interval of time. This interval is suicient to permit'the slow-releasing relay' 223 to deenergize. v

A selecting circuit is now completed extending from ground by way of wiper 213, bank contact with which said wiper is in engagement, armature 251 and its front contact, back contact and armature 260, back contact and armature' 254, wiper 211, bank contact 263, conductor 270, resting contact of spring '322 and saidspring, and primary selecting relay 301 to battery.' l The primary selecting relay 301 is energized to prepare certain selecting circuits at certain of these springs, vincluding the springs 320 and 321,- and to` complete a circuit which extends from ground by way of working contact of spring 319 and said spring, and relay 302 to battery.

The relay 302 is .energized to open the original energizing circuit of the relay 301 and also to open points in the circuits of all A the other relays of the primary selecting group. The relay 301 is not deenergzed by reason of the fact-that there is a locking circuit completed extending from ground through conductor 279, spring-318, workingA contact ofjsaidV spring, and relay 301 to battery. v

Shortly after this selecting operation has vbeen completed, the circuit ofthe line relay 215 is again intermittently interrupted by* a series of interruptions vthat are produced by the second advancement of the switch I .Wipers of the code-sending switch CD. By the operation of the line relay 215' and the stepping magnet 225, the Wipers 211 to 214, inclusive, 1are\ advanced intro'Y engagement with the bank contact set which includes lthe bank contact 264. When the Wipers 211 Another` selecting circuit is *completed` i which extends from ground by Way of Wip;

. spring 40 cuit is completed for er 213,-bank contact with which said )viper-- is in engagement, armature 251 and its front contact, back contactand armature 260, back Contact andarmature 254,. Wiper 211, bank contact 264, conductor 275, and selecting relay 308 to battery. ing relay 308 locking circuit for itself at spring 331, to

-place ground upon the conductor 280 .at 332, and to prepare another point in the selecting circuit at spring 333. The

locking circuit of the relay,r` 308 extends to 1 gagementlwith its twenty-fifth bank contact,

ground upon grounded conductor 279.

By the grounding ofconductor 280, a cirthe relay i220.. The to open one point in 254, to preare a point in the operating circuit 4at the' ront Contact of this armature, vand to' esrelay 220 is energized tablish a locking circuit for itself at armavtheir twenty-fifth set of bank contacts.

ture 255.

After this selecting .circuity is completed, anotherseries of interruptions is produced inthe circuit of the 1ine.relay 215 by the operation vof the impulsing relay atthe dispatchers oiiice.- This series .of interru tions causes the line relay 215 to operate t e stepping magnet 225 to bring the lWipers 211 to 214, inclusive, into engagement'Wih t this point, the impulsing circuit for the line relay 215 remainsv permanently closed and the circuits of both theslow-releasing

relays

223 and 224 arepermanently opened at wiper212., y' l Another result of the operation of the of bank contactsfjinter The select. is energized to establish a' Wiper 212 in engagement'with its twentyfifth bank contact 266 is to complete a cirpoint in the circuit of magnet 225 at armature' 246 leasing relay 217 at the front contact ofthis armature. The circuit of the stepping magcuit for the 'relay 216. The relay 216 isene'rgized 'to open one the stepping and to complete a circuit for the Slow-renet 2 25is opened at armature 246 before the .line relay,v 215 is energized. lConsequently, the Wipers 211 to 214, inclusive remain in `engagement With their' twenty-iiy set of vbank contacts. Another result of the operation of the relay -216 is that an impulsing circuit is prepared at'armature-'245.A A still further result of the operationroffthe relay 216 is that a circuitv is 'prepared' at armature 290 for the slow-releasing relay 221.

The slow-releasing relay 217 is energized to complete a circuit at armature'248 which extends from ground by Way of said arma-v ture and its front contact, frontcontact and l armature 245, front contact and armature H ture 236,.armature 241 and its back Contact,

226 and its back contact,

and'back contact and armature 239 to bat tery.

Thecounting relay v201 is energized over this circuit and operates to complete a circuit atfarmature 228 overa path that eX-.

tends from ground by Way of 'armature 238 and-its back contact, armature'228 and its front contact, relay 200, relay 201, back con- -tact and armature 236, armature 241 and -its back contact, and back contact and armature"239 to battery. This circuit is not eif- .fective to cause the operation of the relay 200 vso long as the original circuit for the relay 201 maintained.

lVhenv the wiper214 is brought into enthe circuit of the slow-releasing relay 219 Wiper '214, bank contact 267, armature 253i -is opened." The slow-releasing relay 219 is,

and its back contact, conductor '281, sprintr itsvvvorking'conta ct, and relay 304 to battery.

`The, relay 304 is energized to prepare a circuit for. the closing coil of the circuit inf terrupter at armature 326, andA to.' complete a short-circuit for the relay 315 bi-passing relay 314 at armature 327.

' Normally, the relay 315 is in an energized condition. The circuit over which this relay is operated extends iromground by Way o-f armature 344 and .its vback contact, back contact and armature 347, armature 349 and its front contact, relay 315 and 'i relay 314 to By .this circuit, the relays 314 and and its Working contact, spring 320 and.

' for the relay 313 at armature 348. The relay 315 is deenergized to complete a circuit that extends from ground by way of back contact and armature 354, conductor 361, back contact and armature 406, stepping magnet 405, and backcontact and armature 425 to battery. Y

The stepping magnet 405 is operated as a buzzer over this circuit to advance the switch wipers 407 to 410, inclusive, until these wipers are brought into engagement with the bank contact set comprising the bank contacts 452 to 455, inclusive. Vhen the wipers are brought into this position, a circuit is completed that extends from ground by way of wiper 409, bank contact 454, conductor 364, armature 350 and its back contact, conductor` 360, and relay 402 to battery. The relay 402 is energized to open the circuit of the stepping magnet 405 at armature 425, to complete a circuit at the front contact of this armature which extends from'battery by way of said armature and its front contact, relay 404, back contact and armature 435, bank conta'ct'with which Wiper 418 is in engagement and said wiper to ground, to complete a circuit at armature 426 over a path which extends from groundiby Way of-said armature and contact and armature 435, bank contact Wi its front contact, slowaeleasing relay 411'and armature 451 and its back contact to battery, and to complete a circuitatarmature 427 over a path that extends from battery by way of relay 40,1,./front'conta'ct andarmaturev 427, armature' 429 and its back Contact, bag

whichwiper 418 is in engagement and said )viper to ground.

The relay 404 is energized 4iso/complete `a`\ circuit for the slow-releasing relay 412 at armature 431. The'relay 4.11 is energized to prepare a circuit for the stepping magnet 451 at armature-432. The relay 401 is energized to complete a circuit for the impulsing relay 400 over a path that extends from ground by Way of armature 426 and its front contact, front contact and varmature 423, re-

lay 400, and armature 451-'and its back contact to battery.

The impulsing relay 400 is energized toA complete a circuit for the line 'relay 509 of connector switch H l at the dispatchersl oliice over a path extending from battery by Way of the upper winding of line relay 509, conductor 460, -ront contact'and armature 422, conductor 461, and lower Winding of line relay 509 to ground. 'i

The relay 412 is operated to open .the circuit of the slow-releasing relay'414 at armature 433, and to open onelpoint in the circuit of the stepping magnet 405 at armature 434. The relay 414 is deenergized after a short interval of time to open two pointsin the circuit of the stepping magnet 450 at

armatures

439 and 440, and to complete a circuit at armature 441 for the slow-releasing relay 416. The slow-releasing relay 416 is energized to open the circuit of the slovv-releas- Qing relay 417 at armature 445, and'to complete a circuit at armature 444 over a path thatl extends from ground by Way of said armature and its front contact, armature 442 and its back Contact, armature 432 and its front contact, stepping magnet 450, Wiper 420, bank contact With which said Wiper is in engagement, and armature 441 and' its back contact to battery. l A The stepping magnet 450 is energized over so the above circuit and operates to open the circuits of the

relays

411 and 400 at armature 451. The relay 400 is deenergized to produce an interruption in the circuit of the line relay 509 at the dispatchers oiiice, and S5 the slow-releasing relay 411 is deenergized to open the circuit of the stepping magnet 450. The stepping magnet 450 is deener` gized to advance the switch wipers 418 to 421, inclusive, one step and to again com ,90

.As a y.result of this operation, a circuit is 100 completed extending from ground by Way .of switch Wiper 410, bank contact 455, bank f l,Contact 456, switch wiper 418, back contact and armatur/ef44'6, and relay 415 to battery.

f-'The relay 415 is/'energized to open the cir- 105 cuit of the stepping magnet 450 at armature 442, and to 1open the circuit of the slowreleasing relay ./416 at armature 443. They ,rotation of ther switch wipers now ceases fon a short interval `of time.

The slow-releasing 'relay 416 is deener-` gized to open another point in the circuit of the stepping magnet 450 at armature 444 and to complete a circuit for the slow-releasing relay 417 at armature 445. yThe sloW- releasing relay 417 is energizedto open the circuit of the relay 415. The relay 415 is deenergized to prepare one point in the circuit of the stepping magnet 450 at armature 442, and to complete a circuit for the slow-releasing relay 416. The slow-releasing relay 416 is operated to complete the circuit of the stepping magnet 450 at armature 444, and' to open the circuit of the slow-releasing relay 417 at armature 445.

The stepping magnet 450 is now intermittently operated under the control ofthe slow-releasing 'relay 411 until the switch wipers 418 to 421, inclusive, are 'brought into engagement with the bank contact set which ,inclidesthe'bank contact'458. During' this patchers oilice.

By the operation of the Wipers of thev `code-sendin r switch CD-l into engagement with the bank contact set Which includes the bank contact 458, a circuit 'is completed whichextends from ground by way of Wiper bank contact 453, .conductor 363, armature V353 vand its back Contact, armature 345 and its back contact, conductor 3.66, bank contact 458, wiper 419, back contact and armature 446, and relay 415 to battery.

The relay 415 is energized to interrupt the action of the stepping magnet 450 in substantially the same manner as. before. The impulsing relay 400 is thus maintained energized and the switch Wipers 418 to 421, inclusive, `remain inv engagement with this set lof bank contacts until the circuit of lthe relay 415 is opened b the action of the slowrel'easing relay 417. herelay 415 is thus deenergized to' bring aloo11*l, ,"thel operation of .the slow-releasing relay\ 416 whereby the circuit of the-stepping magnet 450 is again established. The rotation of the switch .wipers 418 to 421, 1nclusive,now continues.

-until 'these Wipers are brought into engage- `thew'iper 420 opens energized to release ment with the twenty-fifth bank contact set. fDuring this loperation of the switch Wipers, another series of interruptions is produced in the circuit 'of the line relay 509 at the dispatchersofice by the action of the impulsing relay 400. `When the switch wipers are brought into engagement with the twenty-ifth set pf bank contacts, the operation of the Wiper 418 opens the cir. cuit ofthe relay 404 and completes a circuit for the relay 403. The operation fof the circuit of the step- The relay 404 is deits armature 431. The armature 431 then starts to vibrate to send impulses of current to the slow-releasing relay 401 and to the slow-releasing relay 412. The relay 403 isenergized to prepare a ping magnet 450.

circuit for thev stepping magnet405 of the/ -1 at armature 428, to open another point in the circuit of the slowreleasing relay 401 at armature 429, and to `complete a circuit for the relay 413 at armature 430. The relay 401 is iinally deenergized to open the circuit of the slow-releasing relay 412 at' armature 424, and to complete a circuit at the back contact of this iinder switch F- armature for the relay 413. The relay 413 is energized to complete another circuit for the relay 402 at armature 437, t0 place ground upon wiper 407 at armature 436, and to open another point inthe circuit of the stepping magnet 405 at armature 438. l The impulsing relay 400 is deenergized to open 4the circuit normal position,

oiiice." v l The relay 412 is deenergized afteran in Aof .the line relay 509 at the dispatchers p terval ot' time to complete the circuit of the slow-releasing relay 414 at armature 433. The slow-releasing relay414 is energized to prepare a circuit for the 'stepping' magnet 450 at armatures 439 andv 440, and to open the circuit ot' the slow-releasing relay 416 at armature 441. The circuit of the stepping magnet may be traced from ground by way ot armature 440 and its front contact, stepping magnet 450, armature 439 and its front contact, twenty-fifth bank contact with which thev Wiper 421 is in engagement, said wiper, and armature 451 and its back contact to battery. This circuit causes the wipers 418 to 421, inclusive, to be restored to their normal position.

By the restoration of the Wipersto their the circuit of the relay 403 'is opened and this relay is deenergized to open the circuit of the relay 413 at armature 430. The relay 413 is deenergized to remove ground from-wiper 407 at armature 436, to open the circuit of the relay402 at armature 437, and to prepa-rc a' circuit orthe relay 404 at armature The relay 402 is deenergized to restore'certain circuits to normal. The relay 416 is d eenergized to complete a circuit for the slow-releasing relay 417. The slow-releasing relay 417 is'enerergization of the relay 402, the 'circuit of the relay 411 is opened at armature'462'.

gized to open one point in the circuit of the relay 415 at armature 446. By the deenf When ground is placed upon the Wiper 407, n

by the operation of the relay 413, a circuit is completed extending from ground by way of said Wiper, bank contact 452, conductor 362, back contact and armature 352, and relay 314 to battery. The relay 314 is energized to remove ground from relay 402- at armature 350, and to complete a circuit for the relay 315 extending. from ground by` Way otl armature 344 and its back contact, back .contact and armature 347, armature 349 and its front contact, relay 315, and relay 314 to battery. This circuit is not effective-until ground is removed from the wiper 407 by the deenergization of 'the relay 413. The original energizing circuit of the relay 314 is opened in this manner. VThe short-circuit is removed from-the relay 315 and this relay is energized to open another point in the circuit o t the relay 314 at armature 352, to prepare a circuit for the relay 312 at armature 351, and to remove ground from conductor 361 at armature 354.'

In this manner, the code-sending switch andthe associated equipment are operated in order to send back a code to the dispatcher-s ofiice, 'which will be eiiz'ective to inform him ofthe completion ofv the proper selecting operation at the substation. The

i a circuit is completed for the stepping magnet 508 at armature 530. The stepping magnet 508 is energized yto position its paWl and to complete a circuit, at armature 529,

over a path that ,extends from ground'by way of armature 530 and its front contact, armature 529 and its front contact, and slow-releasing relay 503 to battery. The slowfreleasing relay 503 is operated'to prepare a selecting circuit at armature 520, Ato

complete a circuit at armature 521 extending4 from battery by Way-of said armaturexand its front contact, relay4 502, baul: Contact 533, and Wiper 513 to ground, and to prepare a: circuit at armature 522 orthe relay 507. The relay 502 is energized-tocomplete a circuit for the sloW-releasing/ielay 500 at armature 518 and for'the slowlreleasing lelay 501 at armature 519. The relay 500, is operated to .open one point'in the selecting circuit at armature 516, While the relay 501 is energized to open one point in the selecting circuit at armature 517.-

When the rst interruption is produced inv the circuit of the line relay 509, this relay is deenergized to open the circuit of the magnet 508 and also the circuit of thesloW-releasing relay 503. The magnet 508 is deenergized .to advance the switch wipers 512 to 515, inclusive,` one step into engagement with their second set ofbank contacts;

By the operation of the Wiper 513, the circuit of the relay 502 is opened, and a circuit is completed for the slow-releasing relay 500. The relay 502 is deenergized to' open the circuit of the slow-releasing relay 500 and also the circuit of the slow-re easingv relay 501.

The operation of the wiper 515 completes a circuit extending from ground by Way of said Wiper, bank contact with which said Wiper 1s in engagement, and relay 504 toy battery. The relay 504 is energized to place ground upon conductor 541 at armature 523. Another result of the operation of the wiper 515 is that a circuit is completed in multiple with that of the relay 504 that extends from ground by Way of back contact and armature 526, armature 522 and its front Contact, and slow-releasing relay 4505 to' batl tery. Still another circuit is completed multiple with that of the relay 505 which extends by Way of the normally'closed springs l "controlled by armature 527 and relay 507 vto battery.

The relay 507 is energized to open its original energizing circuit at armature 527, and to establish a locking circuit for itself in series with the buzzer 510 at armature 528.

The buzzer 510 and the lamp 511 are loperat ed to inform the dispatcher that the connector or code-sending switch H-l is about to 4.'lhe .line relay-- by reason of the fact that the impulsing rebe operated. The slowreleasing relay 505 of the relay 509, the magnet 508 is again deenegize'd. A Iiyftliis operation, the swltch wipers 5; 1'2fto`5'1i inclusive, are advanced with their third set of bank into enga cc'mtacts. i

509 is now energized and,

lay 400 is maintained ener ized for a comparatively long intervalo time, the slowreleasing relay 500 is permitted to deenergize. As a result of this operation,.a circuit is completed extending from ground by Way of wiper 515,bank contact with Whic said Wiper Ais in engagement,` armature 520 and its front contact, armature 516 and'v its back contact, Wiper 514, bank contact 535, conductor 548, resting contact of spring.v 654 and said spring, and selecting relay 608to battery. y

The selecting relay 608 is energized to prepare'selecting circuits at certain of these springs, to complete a locking circuit for itself at spring 6 53, and to complete 'acircuit for the relay 609 at springl 652. The vrelay 609 is energized to open 'the original energizing. circuit of the relay 608 and, also, all the circuits by which the various relays in the primary selecting groupmight be operated.

The next series of interruptions produced in the circuit of the line relay 509 by the operation of the code-sending switch CD-l bring about the advancement of the switch Wipers into engagement with the bank conpawl and to complete -a circuit for. the slow-releasing relay 503.

.75 Upon the next. interruption 1n the c1rcu1t i ioo tact set which includes the bank contact 536.

Wiper is in engagement, armature 520 and its front Contact, armature 516 and itsbacl contact, Wiper 514, bank contact 536, conductor 542, 4and selecting relay 606 to battery.

The selecting'relay 606 is energized to com plete a locking circuit for itself at spring 631, and to prepare 'a selecting circuit .at spring 630. l

-By the next series of interruptions in the circuit of the line relay 509, the Wipers 512. to 515, inclusive, of theconnector Switch,

H-l are brought into engagement withI their twenty-fifth set of bank contacts. The

spring,

' naling devices,

I rela-y l108 is line relay 509 is then maintained energized until the impulsing relay 400 is released.

By the operation of the wiper 513 into engagement with the bank contact 534, the circuits of both the slow-releasing relays 500 and 501 are openedand these relays are deenergized. Bythe engagement of the wiper 513 with the bank contact 534, a'circuit is completed for the relay`506. The relay 506 is energized to open the circuit of the slowreleasing relay 505. The slow-releasing relay505 is thereupon deenergized to complete a circuit extending from ground by way of wiper 513, bank contact 534, back Contact and armature 524, conductor 540, working contact of spring 630 and said spring, working contact of spring 651 and said and. resistor 622 to battery. This circuit shunts the` relay 600. The relay 600 is deenergized to remove battery from conductor 183 and to complete a circuit for the 'signaling device 616. By the change in sigthe dispatcher knows that the proper selectingaction has occurred at the substation.

When the impulsing relay 400. is finally deenergized at the station, the circuit of the relay 509 is permanently opened and this relay is deenergized to open they circuit'of the stepping magnet 508. The stepping magnet 508 is deenergized toy advance the switch wipers one step. y l

In the'event that 'the wipers 512 to 515, inclusive, are not-in the'rinormal position, a releasingv circuit is completed extending from ground by way of wiper 515, b ank contact with which said wiperis in engagement, armature 520 and its back contact, back contact and armature 529, and magnet 5 08 g to battery. The stepping magnet 508 is intermittently operated over this (circuit to restore the wipers of the/connector switch vI-I-fl to their normal position. v

By the removal of battery from/conductor 183, the circuit of the relay 104 is opened, and this relay is deenergized to open the circuitl of the relay 108 at armature 120. The' deenergized to open the circuit of the slow-releasing relay 146 atVV armature 136. The relay 146 is deenergized to open another point in the circuit of theJstepping magnet 142. l The dispatcher, having been informed that the desired selecting,l action has occurred at the substation, may now operategthe'control devicev 155, whereby three interruptions are produced in the circuit` ot the relay 144. The relay 144 is, consequently, deeiiergized three times to produce a corresponding number of interruptions in the circuit of the line relay 215 of the connector H at the substation.

Upon the first deenergization of the relay 215, the short-circuit is removed from the relay 200 and this relay is permitted to opcrate. ,Upon operating, the relay 200 yprepares acircuit for the relay 210 at. armature 227, and at armature 226 prepares a circuit for the relay .203.- When the relay 215 is energized, the circuit ofthe relay 203 is completed/and this relay is operated to com- .plete a circuit for the relay 202 at armature 231. The circuit for the relay 202 is effective upon the deenergization of the relay 215. The relay 202 operates to prepare al1- other point in the `circuit of the relay 210 at' armature 230..l When the relay 215 is energized, the circuit of the relay 205 is closed and this relay is operated to prepare a circuit for the relay 204-at armature 234. The circuit of the relay 204 is eiective upon the deenergization of the relay 215.y` Vhcn the relay 2 15 is operated, acircuit is closed i for the relay 207. lThe relay `207 is energized to complete a circuit for the relay 206 at armature 2,37.

By, the energization of the relay 204, a circuit is completed which extends `from ground by way of front Contact and armature 233, front contact and armature 254,. wiper 211, twenty-ith bank contact, conductor 274 and relay 305 to battery. The relay 305` is energized to complete a circuit at armature 328 for the closing coil 306' o't the circuiti' interrupter C. The closing coil of the circuit interrupter C brings about the closure ofA the unit. By the operation oi' the auxiliary gsvt'tch '329, the circuit of the closing coil "306 is opened and the circuit interrupter is `latched in closed position by the usualmechanical means.

The oper tion of the auxiliary switch 330 completes l a circuit which extends fromround 'by' "way of y said switch, armature 351 and its front contact, and relay 312 to battery. .The relay 312 is energized lto open 0the chcuitxofft e relays 314 and 315 at armature 344, and itselffrom ground through battery, relay 312,make ntact at armature 351 and front contact-andv armature 344 to ground 'at `the front contact of thisv armature.

315-' is deenergiz'ed to initiate the hunting 'action of the finder switch F-l in the same manner as previously described. r The relhl 314 is deenergized to prepare one pointin the testing circuit at armature pare a point in the circuit of the relays 314 l and 315 at armature 347. y

The operation of the finder switch F-l prepare alocking circuit for The relay 75350, and to complete a circuit for the slow- 'y and the code-sending switch CD-l, as well as the connector switch H-1, occurs in substantially the same manner as before described. However', inasmuch aS the relay 312 is now energized, the second code point is changed Jfrom bank contact 458 to bank contact 457 so that a different code is sent pletev a circuit for the magnet 142 over a .to normal.

to the dispatchers olice. This difference inl code brings about the energization of the selecting relays 608 and 605.

en the code-sending switch CD-l and the connector switch H'-1 are in their twenty-fifth position, a circuit is closed for opera-tin the relay 600 and this relay is energize to bring 'about a 'change in the supervisory signals 616and 617 to inform the dispatcher that the desired action has taken place at the substation. l

Atthe substation, by the operation of the relay 413, ground is momentarily connected to the conductor 362. about the energization of the relay 314 and also they operation of the relay 315.' In this manner, the starting circuits'of the finder switch F-l are opened and the relay 312 is again placed in circuit with the auxiliaryA switch 330. The reason for again connectingthe relay 312 tol theauxiliary switch 330 is to secure the operation of the finder switch and the code sender in the event that the circuit interrupteris operated by apparatus at the substation.' l A It will be seen that, if the circuit interrupter is operatedfor any reason, the relay 312 will be deenergi'zed to open the circuits of the

relays

314 and 315. This action will initiate'the operation. ofthe finder and .code

vsender switches in the same manner as before.

The dispatcher havin been informed of the completion ofthe esired operation at the substation, he will restore the key K-2 By this operation, the circuit of the'relay 144 is opened and this relay is deenergize to open the circuit of the line relay 215 of the connectorvH at the substation. Another result of therdeenergization of the relay 144 is that the circuit of 177 is opened at armapath that extends from ground by way of armature 164 and its front contact, magnet 142, armature 160 and its back contact, front contact and armature 166, twenty-fifth bank contact, wiper j154, and armature 163 and its back contact to battery.

The stepping magnet l42fis now operated to advance the switch wipers 151 to 154,V

inclusive, into their normal position. This operation causes the opening' of the circuit of the stepping magnet 142, whereupon its operation switch wipers 151, the circuit of the relay 143 is opened and this relay is deenergized to open another point in the circuit of the relay 144. In this manner, the apparatus lat the dispatchers otlice is restored to normal.

By-the deenergi'zation of the line relay 215, the circuits ofthe slow-acting relays 217 and 218 are-.openedat' armatures 243 This operation brings thel ceases. By the movementof the` is opened ycircuit from the relay 209, thereby permit-r operate in series withthel ting this relay to counting relays that are energized. The relay 209 is energizedl to completefthe circuit of the'v relay 2 08 at armature 240, fThe relay 208 is operated to open the circuitfo'f all theV counting relays'and also the circuit of the relay 209 at armature 238, and to co plete a circuit for the slow-releasing relay 221 at the front contact and armature-291'.,

deenergized to restore*- The relay 2,18 circuit for thev stepping magnet 225 over a path that extends" The relay 217 is certain circuits to normal. is deenergized to complete a -from ground by way of armature 290 and its front contact, armature 291 andits fron-t.

contact, armature 251 and back Contact and armature 225 to battery. The magnet 225 is 'operated its back contact,

262, and magnet to rotate the .wipers 211 to 214, inclusive,

from their twenty-fifth position. By this operation, ground is removed fromv conductoi` 281 and the circuit of the relay 304 is opened. By the deenergization ofthe counts ing relays, certain circuits are restored to normal, among which is the circuit forthe relay 305.

By the movement of the wiper 212,- the circuit of the relay 216 is-opcned and this relay is deenergi'zed. of the relay 216', the

It will be seen that absolute positivenessof operationis acquired by providing means ,By-the deene'rgizatio circuit of the sloweae 5f ing relay 221 and the stepping magnet 225 is opened.

for giving the dispatcher a checking signal4 in order to inform him that the desired selecting action has occurred at the substation. It is obvious that, in order tosecure proper selection of the apparatus units at the substation, the code-sendiiig switch -CD must'A operate in synchronism with the connector switch H. Unless these switches are oper-A ated in sychronism, the pause in the impulsing, which occurs with the code-sending switch'CD in its twenty-fifth position, will not be effective to release relay 219 to operate the selecting relaysand there will be no answer-back signal returned to the dis patcher. The locking circuit for relay 219 at the 25th position and unless the pause occurs-at this time, deenergize. lease the key K-2.

By this'operation, the circuit of' tlie'drelay@ 4 144 is opened and this relay is energized to permit the deenergization of the relay. 177. The deenergization the wipers 151 to1154, inclusive, to rotate to relay 219 will not. The dispatcher will then re-` of the relay 177 causes their normal position. rllhe deenergization of the relay 14A opens the circuit of the line rela 215 at the substation. The release y of the re ay 215 opens the circuit of the relay 216 is not energiped unless the switch wipers' are in engagement with their twenty-fifth set of bank contacts.

In the present case, it has been assumed thatthevvipers of the connector switch H did 'not operate in synchronism with' the wipers of the code-sending switch CD and that switch H will not be on the th posimove'the short-circuit to rotate the switch wipers -thev relays 208 to 210, inclusive,

tion. The relay 2-10 will be energized to refrom the relay 209. By the deenergization of the relay 218, a circuit will be, completed extending from ground by way of wiper 213, armature 251 and its back contact, back contact and armature 262, land magnet 225 to battery.

The magnet 225 is intermittently operated tol their twentyfifth position.

W'hen the `wipers twenty-fifth position, gizved (and is operated are brought to their the relay 216 is enerto complete a circuit for the stepping magnet over a path that extends from groundV by way of armature v290 and its front contact, armature 291 and its front Contact, armature 251 and its back contact, back contact and armature 262, and magnet 225 to battery. The magnet"225 is thus operated to restore the wipers 211 to 214, inclusive, The counting relays 200 to 207, inclusive, and are released in an obvious manner. e

` The code-sending operation at tlie substation now reoccurs in the same manner as before described, as the relay 109 is'operated, when tlie switch wipers are brought to their normal position to complete the circuit vfor the slow-releasing relay 110. The operation of the relay 11.0.initiates the code-sending operation in the same manner as before.

ln the event that the code-sendingswitch Cl) and the connector' switch H have been properly operated to bring about the desired selecting ,action at the substation, and the connector H-l has not been properly oper ated by the code-sending switch CD-l, the dispatcher will not receive any signal indcative'oif the completion of' the selection.

This is truc, because, in order to Secure proper -operation of' the selecting apparatus, it is necessary thatthe wipers of the connector H1 move in synchronism with the wipers of the codescndingv switch CD-l so as to provide a sufficient period of time to permit relay 505 to deenergize. vIn order to secure reoperation of the selecting apparatus the dispatcher willrestore the keyl K-2 to to their normal position.`

normal. The action at the dispatchers oice is the same in this case.

At the substation, the circuit 'of ythe line relay 215 is opened to remove the circuit from the relay 206 and this relayis operated to remove the short-circuit from the relay 209. By the operation of the relay 209, the apparatus at stored to' normal in the same manner as before. The code-sending operation at the dispatchers office will now reoccur to again i initiatethe operation of the code-sending switch (JD-*1 at the substation in substan tially the same manner as before described.

It will be noted that, after the operation of one of the primary selecting relays 301, the j relay: 302 is operated. The operation of this relay prevents any other relays in the primary selecting group being operated. Consequently, this eliminates the possibility -of false selectionby defective operation of the connector switch H.

In a likemann'er, the operation of one of the relays in the secondary selecting group causes the operation of the relay 220, and this relay opens the selecting circuit so that no other relays' in the vsecondary selecting group maybe operated. This also prevents improper operation in the event of the completed operation of the connector switch H.

units at said second station, a code trans.

mitter at said first station, means including said code transmitter for transmitting different code combinations of impulses to said second station individual to said units, a code receiver at saidsecond station responsive to the code combinations of impulses for selecting one of said apparatus units, means for checkingthe transmitted codes with the received codes, means operative if said codes check for conditioning the apparatus unit corresponding to the code for operation, a normally inoperative code transmitter at said second station, means whereby it is rendered operative by said last-mentioned means -for transmitting codes to said first station individual to said conditioned apparatus units, a code receiver at said first station responsive to said codes from said secondstation code transmitter, means controlled by said code receiver for tions conditioned at said remote station and means whereby the conditioned units may be operated from said first station.

shortfrom the sp1rit and scope a first station,l

the substation is re- The same statement is true with respect to i indicating the selec-v stati'on, a second station,

ratus umts at sa1d second station, amovable 1m-reve 2. In a supervisory control system, a first aplurality of appa- .code transmitter at said first station, means including said code transmitter for transmitting code combinations of impulses to said second station individual to the units, a movable code receiver at said second station responsive to said codes for selecting said apparatus units for operation, means operative only atv a predetermined position of -said code 'transmitter and said code receiver ifV said code transmitter and said code receiver have moved. in'synchronism, for conditioning the apparatus unit corresponding to the transmitted code for operation, a code translmitter at said secondl station, responsive to said last-mentioned means, for transmitting av code to said first station individual to code receiver said selected apparatus unit, a at said first station, responsive to said second station code4 transmitter for indicating the apparatus unit selected for operation and means for thereafter operating the conf. ditioned unit from the first station.`

3. In a supervisory control system, a first station, a second station, a plurality of apparatus units at second station, a movable code transmitter at said first station, means including said code transmitter for transmitting code combinations'of impulses, to said second station individual to the units, a movable code receiver at said second station responsive to said codes for selecting said apparatus units for o eration, means operative only at a predeterimned position of said code transmitter and said. code receiver. in the event that said code transmitter and said i code receiver have moved in synchronism,

for conditioning a selected apparatus unit for operation, a code transmitter at said second station responsive to said last-mentioned means for transmitting a code to said first station individual to said selected appa-- ratus unit', a code receiver at said first station responsive to said second-station code transmitter for indicating vthe apparatus unit selected for operation and a second code transmitter at said first station for transmitting a predetermined code to said second station for operating said selected apparat tus unit.

4. In a supervisory control system, a first station, a second station, a plurality of apparatus units at said second station, a signaling device at said first station individual to each of said apparatus units, a movable code transmitter .at said first station, means including said code transmitter for transmitting code combinations of impulses to said second station, a movable code receiver at said second station responsive to said code for selecting one of thesaid apparatus units means operative at a pr@- termined position ofi said 'code transmitter and said code receiver only in the event that said code transmitter and said code receiver have moved in synchronism, for conditioning the selected apparatus unit for operation, a movable code transmitter at said second station, responsive to said last-mentioned means for transmitting a code to said first station individual to saidselected apparatus unit, a movable code receiver at said 'first station, responsive to said second-:station code transmitter, means operative in the event said second station code transmitter and first` stationcode receiver are in synchronism for operating a signaling device individual to said selected apparatus unit and means whereby said selected unit may thereafter be operated from said first station.

a second station, apparatus units at thesecond station, Aoperating means individual thereto at the first station, signal devices at the first station individual to the units and controlled by the position of the units for indicating the instant position of the units, means wherebyY the operation of'the individual operating means changes the indication of the corresponding indicating means and simultaneously causes the transmission of a code corresponding to` the individualy 0 erating means, means responsive to the co e for selectingthe individual umt for opera tion, means responsive-to the selection for then reoperatin the indicating means to its original con ition and means for thereafter operating the selected unit from the first station.

6. In a signaling system, a first station, a second station, a plurality of apparatus units at said second station, operating means individual to said units at said first station, signaling devices individual to and controlled by the position of each of units at 'said first station, a code transmitter at said first station, a code receiver at said second station, means responsive to the operation of any one of said operating-means responsive instantaneously to the operation of said operating means for changing the combinationsof'impulses to said second station yin accordance Withthe operated means, a code receiver at said second station -responsive to a code for selecting one of said apparatus units vand conditioning it lfor operation, means responsive to y said selection for operating said signaling device individual to said unit at said first station to its original condition, means at said first station for operating said selectedapparatus lunits and means at said second station responsive to the operation of said apparatus 5. In a signaling system, a first station,

said apparatus" 4for operating .said code transmitter, means responsive to the operation of said code transmitter for transmitting codel lac units for again operating said signaling devices to indicate the operation of said apparatus unit.

ond station, operatlng means thereto at the first station, signaling devices -7. In a signaling system, a first station, a second station, apparatus units at the secindividual cation of the corresponding. indicating a selecting apparatus simultaneously means,

means for selecting one controlled by said of the apparatus units individual to the op erating means, meansresponsive to the selection for reoperating the indicating means to the original condition and means for thereafter operating the selected unit from thefirst station.

In testimony whereof, I have hereunto 'I subscribed my name this 22nd day of January, 1925.

THOMAS. U.` WHITE.