US1864553A - Telephone system - Google Patents

Description

June 28, 1932. R. L. QUASS 1,864,553

TELEPHONE SYSTEM Filed Dec. 6. 1930 5 Sheets-Sheet 1 LlLU o a. g

I U '3 M n N m P Q o n J u n I A'l II L 1H m g I a u k I U El I 2' v I; Q

/N 5 N TOR 4 R.L. QUASS BY ATT NE) June 28, 1932. R. QUASS TELEPHONE SYSTEM Filed Dec, 6, 1930 S'Sheets-Sheet 2 www No 98.3 .33 to 9 *5 INVENTOR R. L QUA $5 ATTORNEY June 28, 1932. R uAss 1,864,553'

TELEPHONE SYSTEM Filed Dec. 6, 1930 3 Sheets-Sheet 5 .4 TTOR/VEV Patented June 28, 1932 ss srA r-ss earner oFFicE nALrr-i L. emission nnwrnon nn, new JERSEY, As'sIGn'on To BELL TELEPHONE'LAB ORATOILIES, INCGRPOEATED, OF KEV! YGRK, 13'. Y., A CORPORATION OF NEW YO RK a nnnrrzonn SYSTEM a licant file'd' December aieso. Serial no. soaesa This invention relates to telephonesystems and particularly to means for checking-calling subscribers numbers, and the object of the invention 1s to simplify and nnprove the checking of numbers when applied to automatic systems.

Heretofore, systems which an operator may check the number given by a callingsubscriber who has estab lished automatically a connection'to the operatons'position by establishing automatical-.

ly a separate connection to the calling subscribers line and causing the application of a tone over this second connection, which 3 tone is transmitted over the original connecment, in systems of this kind in which the calling subscriber has established an automatic-connection to'an operators position in the distant oiiice over a trunk line, whereby the operator may establish over asecond trunk 21 separate number checking connection to the calling subscribers line and to the trunk line used by thecall-ing subscriber, and whereby an alternating current signal is applied from the separate connection to the subscribers line for transmission over the automatic connection established by the subscriber back through the separate connec-- tion established by the operator to' the subscribers trunk line, and whereby means re sponsive to this alternatingcurrent signal and to the establishing of the separate connection to the subscribers line causes a direct mitted over the second trunk to the operators position-to flash the lamp thereat to inhave been used indicate this condition. This interrupted direct currentsignal is in, this-case'efl'ec'ted biy means solely responsive to the establishing of the separate connection to the wrong subscribers number.

Another feature isanqarrangement where'- by, whether the lamp indicates either of these conditions, the separate number checking, connection is automatically released when the signal is transmitted to the operators position. This release is solely responsive to the establishing of the separate connection to a subscribers line.

Another feature is an arrangement for applying number checking toprivate branch exchange lines. The arrangement is such that if the calling subscribers line is one of a small group of private branch exchange lines this group is selected by a switch in the number checking connection in the same manner as the line of a single subscriber.. This switch is themdue to certain conditions encountered on :a special terminal for each line, caused'to hunt over the entire group of private branch exchange lines. rDuri-nglthis lnin'tin'g an alternating current si -na'l isapplied to the sleeve terminals of these lines in succession for transmission back through the connection used by the callingsubscriber. If, on the other hand, the calling lineis one of a large group of private branch exchangeu lines, this switch merely selects 'a'single' set of terminals representinga sub-group of this group of lines. This selection then'causesan auxiliary switch to be 'actuatedtohunt' over and apply the alternating current signal to the sleeve terminals of all lines in this sub:- g-roup in succession. In this manner a group or a: subgroup of private branch exchange lines, over a line of which a call: hasbeen made,is checked rather thanthe line itself.

This invention is illustrated in the accompanying drawings inwh-ich Figs. 1,2 and 3- may be arranged as shown in Fig.ifor the disclosure of anumbercheckingisys'tem.

Referring to the drawings a connection, froma calling subscribers station at 1 is shown extending from a call originati-ng-ofiice A th-rough a line finder LF, a selector Send a connector C over a'trunk 'llto a distantoliice-z B, where trunk T terminates in a jack TJ at a number checking toll operators position TO. A number checking connection embodying features of this invention is shown terminating in office B in a jack 300 and extending over trunk TC to oflice A, and the circuits as shown in Figs. 3, 2 and 1 may be used for number checking of individual lines, lines in private branch exchanges having less than ten lines and lines in private branch exchanges having more than ten lines.

To establish a number checking connection the operator at B seizes the number checking trunk TC and first dials two numbers to connect the trunk connector 301 with the trunk T- and then dials four additional numbers to establish the connection to the sleeve of the calling subscribers line in case of an individ-' ual line. This connection will extend over an intermediate connector 200 and a final connector 100. If the connection is for an individual line the intermediate connection 200 is actuated to select a set of terminals such as 201; if the connection is for a line in a P. B. X. having less than ten lines the intermediate connector 200 is actuated to select a set of terminals such as 202, and if the connection is for a P. B. X. having more than ten lines, a group of terminals such as 203 are selected by connector 200. In'the final connector 100 if an individual line is desired the brushes 101 are selected by the connector 200, if a line in a P. B. X. having less than ten lines is desired brushes 102 are selected and if a line in a P. B. X. having more than ten lines is desired brushes 103 are selected. In the latter case the selectiton of a line in a P. B. X. having more than ten lines may be done by switches such as 104, which are selected by the selector 100 selecting a terminal representing a sub-group of lines in this P. B. X. Such sub-groups may comprise any number of lines up to 20 and have their sleeves connected to the banks in switch 104.

Assuming now that the operator at B has answered the call from subscriber 1 by inserting the answering plug of the regular toll cord shown diagrammatically at T0 into trunk jack TJ and received his number she will proceed to check it. The number checking cord shown at 303 will be used for this purpose and the plug thereof will be inserted into the jack 300 of the number checking trunk T0. The number checking cord "1 303 may include av polarized relay 324 and a signal 325 controlled thereby. The windings of relay 324 may be connected in series to the tip and ring of the plug of this A cord and a dial circuit 326 may also be pro-- vided in this cord for association with the tip and ring of the plug. The immediate effect of this connection will be the operation of relay 304 over a circuit from battery, ar-

mature and back contact of the release magnet 305, lower winding of relay 304, lower inner armature and back contact of relay 306 to the ring conductor over the loop established through the dial circuit 326, back over the tip conductor, upper armature and back contact of relay 306, upper winding of relay 304 to ground. Relay 304 closes an obvious circuit for the actuation of relay 307. Relay 307 establishes a connection to ground on its lower armature and front contact for a common ground lead 308 and prepares the dialing circuit for the operation of the trunk connector 301. The operator now dials two numbers to actuate the trunk connector 301 to establish a connection to trunk T. On the release of relay 304 in response to the first impulse a circuit will be completed for the vertical magnet 309 from battery, winding of this magnet, winding of relay 310, vertical off-normal contacts 311, lower inner armature and back contact of relay 312, lower inner armature and front contact of relay 313, second lower armature and back contact of relay 306 to the common ground lead 308. It should be noted that on this first release of relay 304 relay 313 was operated over a circuit controlled by relays 306 and 307 so that this circuit for a vertical magnet 309 will be closed each time relay 313 is actuated by the release of relay 304. It should also be observed that relay 313 will be held operative until the vertical magnet 309 is actuated by a holding circuit from battery, winding of relay 313, lower outer armature and back contact of relay 306, lower outer armature and front contact of relay 313, second lower armature and back contact of relay 312, armatures and back contacts of vertical magnet 309 and rotary magnet 314 to ground. This insures the operation of the Vertical magnet 309 for each re lease relay 304.

As the circuit for the vertical magnet 309 also extends through the winding of relay 310, this relay will operate and being slow in releasing will remain operative during the sending of this series of impulses. At the end of this series of impulses it will, however, release and prepare circuits for the reception of the second series of impulses for the operation of the rotary magnet 314. The clrcuit for the rotary magnet 314 may be traced from battery, winding of this magnet, winding of relay 315, lower armature and back contact of relay 310, vertical off-normal contacts 311 and the circuit to ground on lead 308 as hereinbefore traced. Relay 315 is operated inthis circuit and remains operated during the pulsing. At the end of the second series of impulses the brush of the trunk connector 301 makes connection with the sleeve conductor of the trunk T used by the calling subscriber. Relay 315 now releases and closes a circuit for the operation of relay 312 from battery, winding of rotary off-normal contacts 316, armature and back contaeuof relay' 315 to ground on lead 308;" Relay 312prepares a connection from the sleeve of trunk T, through connector 301' over itslow-er outer armature and front contaet to analternating current responsive relay- 318 which w-illbe operated when an alternating cur'rentsignal is received over this sleevefrom the callingsubscribers line sleeve when connected to by switches 200 and 100 as w-ill hereinafter be-described. Relay 312 also preparescircuits for the control of these two-"switches Th'e'next' op'erationon' the part of the operator "will be-to send two series of impulses to 5 control the intermediate connector 200 to select a final "selector such as 100 for theextension of the connection to an individual line, toa l B; X. office having less than ten lines, some a B.X. ofiice having more than ten olin'es; When the operator sends the next series-of impulses, relay 313 will be operated as usualand'theimpulses will be transmitted over contacts of relay 312 for the operation of the 'verti'ca-l magnet from battery, gswindin'g of'th'is magnet, second lower armature an'd back'contact of relay 205, winding of relay 206, upper armature and back contact'of relay 207, make-b'efore-break contacts I of relay206, lower-inner armature and front ao'conta'ct'of relay 312, inner lower armature and'frontcontactof relay 313, second lower armature and baclrcontact of relay 306 to ground on: lead 308. The locking circuit for relay 313' will be extended from ground at aethaarm'ature of vertical magnet 204;, armature-'andback contact of rotary magnet 208, inner upperermature and back contact of relay 205, second lower armature and front cont-aet' ofrelay 312, lower outer armature andcfront'contact of relay 313, lower outer armature and-back: contact of relay 306, winding." of relay 313 to battery. Relay 206 also operatesin the circuit for the vertical magnet 204. The circuit for this magnet and relay will therefore on the operation of relay 206 be extended "through the upper armature and frontcontact of relay 206. Relay 206' in operating closes a circuit fortheroperation of relay 207 from battery, fiawinding ofthis relay, lower armature and front contact of relay 206, inner lower make before-break contacts of relay 209, conductor 2I0, second lower armature and back contact of relay 306 to ground on conductor 308. fifi Relay 207 in operating prepares a locking circuit for itself through its lower armature and front contact to the ground on conductor308-, -ind'ependent'of relay 206 whichis relea'sed' at the end of this series of impulses. When thenext series'of impulses are sent the circuit-will extend over the make-beforebreakcontacts of relay 206, and upper armature andfront contact of relay 207, lower makebefere hreak-contactsof relay 211, lower outer armature and back contact of relay 212, windingof relay 211, third lower'armae ture and back contact of relay' 205, winding of the rotary magnet 208 to=battery. It willbe noted that the: locking circuit for relay 313 will still extend to the ground at the verticalii magnet 204 and be controlled by the armature andfbaclr contact of the rotarymagnet 208. Relay 211 operates in' series with the rotary magnet'208, remains operatedduring.-v pulsing and closes the pulsing circuit through itslower armature and front contact independent of relay 212; At the end' ofthis seriesof impulses relay 211 releases: and circuits will be preparedfor the control of the selected final connector When relay 21 1 operated a circuit: was: closed for the operation of relay 212-fromf battery, winding of this relay, upper outer armature and front contact of relay='21-1, inake-before-break contacts of relay 209 to: ground on conductor 210. Relay-212' in op-: erating provides a locking circuit for itself through its lower inner armature and front contact directlyto the ground on' conductor" 210 independent of relay 211. Now, there fore, when relay 211 releases a circuit will :be 7 completed for the operation'of relay209from battery, winding of this relay, upper outer armature and front contact of relay 212, upper middle armature and'back contact-of relay 211 to ground on conductor 210. Relay 209 in operating closes an obvious circuit for the operation of relay 205. Relay-205 in operatingclosesa circuit for relay 1060f connector 100, from battery, winding of this. relay, upper armature and back contact/ofthe release magnet 107 to the release control terminal of the set of terminals through which connector 200 has been connected witht connector 100. In this case th'e'conn'ectiorr" will extend through the upper'terminalof the group 201 over the corresponding brush of connector 200, upper'outer armatureian'd front contact of relay 205 to ground on conductor 210. The purpose of the operationof' relay 106 isto prevent the release of'the' connector 100 prematurely, as this relay opens the circuit for release 'magnet 107 which will be closedthrough the'vertical off-normalconitact 108 when the vertical magnet'llO'moves the connector 1.00 off normal position. When relay 209 operates itprepares a lockingv cir-' cuit 'foritsel'f through its lower inner armatureand front contact to the ground on conductor '210 and? also opens the locking circuit for relay 212 which is thereby released. It should be noted thatthe locking circuit for relay 207 is also opened by the operation of relay 209 so that this relay will also release at this timeto prepare the circuits for the conconnection with a icalling subscriber having an individual line. The last two series of impulses will now send. The first impulse of the next series closes a circuit for the vertical magnet 110 from battery, winding of this magnet over the vertical pulsing terminal of the group 201, to wit, the fifth terminal, the corresponding brush of connector 200, second lower armature and front contact of relay 205, winding of relay 206, upper armature and back contact of relay 207, make-beforebreak contact of relay 206 over the pulsing conductor to ground on lead 308 as controlled by relays 312 and 313. The locking circuit for relay 313 will be extended over the second brush of connector 200 and the second or looking terminal of group 201, armatures and back contacts of the vertical magnet 110 and the rotary magnet 112. It should be noted that this locking circuit is also controlled by relay 205 and extends through the upper inner armature and front contact of this relay. Relay 206 operates in the pulsing circuit as before and closes the circuit for the operation of relay 207 which looks to the ground on lead 210. At the end of this series of impulses relay 206 releases while relay 207 remains operated so that the circuits will now be prepared for the operation of rotary magnet 112. The pulsing circuit for the rotary magnet extends fromlaattery winding of this magnet, the sixth or rotary pulsing terminal of the group 201 and the corresponding brush of connector 200, third lower armature and front contact of relay 205, winding of relay 211, lower outer armature and back contact of relay 212, make-before-break contacts of relay 211, upper armature and front contact of relay 207 to the pulsing circuit extending to ground at lead 308. The locking circuit for relay 313 will be the same in this case as series of impulses.

The circuits are now in condition for the transmission of alternating current signals over the sleeve connection extending from the calling subscriber to trunk connector 301 and alternating current responsive relay 318,

as connector 100 has placed its brushes 101 in connection with terminals associated with the terminals representing the calling subscribers line.

In connector 200, two marginal relays 214 and 215 control the operations in regard to the application of the alternating current signals over the sleeve of the calling subscribers line. In this case, when an individual line is involved, relay 214 only operates due to the condition on the lower terminal connected to the lower of the two brushes 101. This brush encounters a connection to ground through a resistance. This resistance is of such characteristics as to permit relay 214 to operate but prevent relay 215 from operating over a circuit completed from battery windings of relays 215 and 214, lower inner armature and front contact of relay 205, upper inner armature and back contact of relay 211, upper inner armature and front contact of relay 212, the fourth brush of connector 200, lower brush of connector 100 and corre sponding terminal through the resistance to ground. It should be noted that on the operation of relay 205 a circuit was closed for the operation of relay 216, to start the alternating current producing device 217 to opcrate. This device consists of the usual interrupting relay 219 and a tuned circuit. Therefore, when relay 214 operates an alternating current signal from this source will be passed over the lower armature of front contact of relay 214, the third brush of connector 200 and the upper one of the brushes 101 of connector 100 to the sleeve of the calling subscribers line.

This alternating current signal will now be transmitted over the sleeve of the connection through the line finder LF, selector S, connector C, to the selected terminal and brush of trunk connector 301, lower outer armature and front contact of relay 312 to the alternating current responsive relay 318. Relay 318 now operates and closes in turn an obvious circuit for relay 319. The operation of relay 319 closes a circuit for the o aeration of rela 320 from batter windin of this relay, armature and front contact of relay 319, upper armature and back contact of relay 221, upper armature and front contact of relay 209 to ground on lead 308. Relay 320 looks to the ground on lead 308 through its upper inner armature and front contact independent of relays 221 and 209. A circuit is also closed by the operation of relay 214 as follows: battery winding of relay 322, upper armature and front contact of relay 304, upper outer armature and back contact of relay 315, upper armature and front contact of relay 214 to ground. The operation of relay 322 closes a circuit for the operation of relay 306 from battery, winding of relay 306, upper armature and front contact of relay 322 to ground on lead 308. Relay 306 in operating reverses the con nection from battery and ground for the tip and ring conductors over trunk TC to cause the polarizing relay to operate and light signal 325 to indicate to the operator at B that the calling subscriber gave the correct number. Relay 306 in operating also opens the connection to ground for lead 210 at its second lower armature and back contact and causes relay 209 torelease. Relay 209 is slow connectionsfrom ground through the lower outer armature and'front contact of relay 215, left hand armature and front contact of in releasingE to permitlrelay 320 to operate andhlock before it; releases.

I ;Relay.,,209 inreleasing causes: the release of 'relay 205 and thisrelay in turn causes the release of relays 207, 214:, 216 and 106. Relay 21 4 vdisconnectsthe alternating current signal from the sleeve of the calling subscrihers line and releases relay 322. LRelay. 106. closes. the circuit for-the release magnet 107 so that connector, 100 will now return to normal. Relay ,212 also, releases on the release of relay 205.

The discontinuing of thealternating current signaland release of connectorlOO causesalso vthe. release otalternating current responsive relay 318 andrelay. 3.19. T he operatorat B seeingrsignal 325 lighted will know that the 'Gallingsu-bscriber :gave the correct number and removes thev plug of the,cord 303 from thejack 800 of the number checking trunk TC. The removal ofthisplugcauses the release 0t relays 304 and ,307. A circuit is now completed for therelease magnet 305 for qthe release of the trunk connector 301. -;QiIC1lit may be traced from battery,..winding of this magnet, Vertical ofi-normal contacts .311, upperarmatureand back contact of re- This lay 307, lower armature and back contact of relayy304 toground. The release of relay 307 .causesthe release .of relays320and 306. The release of -relay 307 willalso close a circuit tortherelease magnet 223 from battery, .xvinding of this magnet,Vertical oil-normal .contact22e to groundat the lower armature .andback contact of relay .307 to cause the connector 200 to return to normal.

;A descriptioncwill now bemade of. the

cuitfrom groundto the interrupting circuit arrangementf226. to close a circuit for the operation ofrelayj227 which in turn closes vacircuitforthe operation of relay 228.and thisrelay in turnopens the circuitfor relay 227 which again-releases relay 228. These relays will be alternately operated and released in this manner to establish momentary relay 228, lower inner armature and front contact of relay 215, winding of relay 229 to battery to alternately operate and release this relay. i-Relayj 229 now controls the circuit fortherotary magnet 112 which extends from battery, .Winding of this magnet, the

.@ sixth :brushnf the connect-@200, .upper:

nor armatureand ,front contactof relay 215', armaturei-andjf ront contact of relay 229 to ground reoperate connectorjlOOto pass from the terminal of one P. B. X. exchange line to another in this group untilthe terminalof the last line has been reached as ground will be encountered on these terminals. Thelower terminal of the lastline will have a connection through a resistance to ground-to per- .mit relay 215 to release to open the control circuits for rotary magnet 112. Relay 214:

-when operated appliesthe alternating current signal {from-source217 to. the upper terminal of each line insuccession as thebrushes 102 of, the connectorlOO pass over these, termi.nals..

NVhen the-sleeve terminal of the P." 'B. line connected to trunk Tis passed bythe upper one ofthe brushes 102the alternating current signal will be transmitted over the trunk through connector 301- to cause-theoperation, of relay. 318. The peraticns ofthe circuits from" this time onare exactlythe same as hereinafter described in connection with the, number checking for an individual line.

A description will now be made ot number che king fo a I. "B. su sc ibefl lin when located in a P 'Bgc X.having'more than ten lines. lnthis case the connectorj 20 0 will select a terminal group such -as 203 which indicates the P.-B."X. number and the con- ,nector 100 will be actuated to select a subgroup of a a subscribers line in this P.j B. 'X. i In t i subg oup he, call ngu cr er li will be located. Brushes 1Q31will now-bealsejd and thclowenbrush wil -enc0untera ce ne tion to ground through, a; high resistance. If

the connectionsyare made as shown in Fig.1,

the subgroup controlledf-bycthe bIiUSh and .bank 115 will be selected bYLQnnectorlQO.

Asthelower oneof the brushes. 103 finds this high resistance conditionto ground; neither relay 214 nor relay ,2 15 .Will" be actuated. However, theconnection from this terminal will as shown. extend from battery at tl1e winding of relay 21.5 over the circuithera inbefore described,.and through the lower one of the brushes-108. left hand make-hefiorebreak contacts of relay 116,-right hand windingofrelay;217, outer right handarmature W land back contact of relay218 to groundat' the brush ,and first terminal of bank ,;119.

Relay1'17 operatcsin this circuit and pro- Vides ,a locking circuit for itself frem battery, left hand. winding, inner ,make-beforebreak contacts, of -relay 116, inner left hand armatureand front contact of relay 1 l7,an]d

the, corresponding armatures and back y contacts of relays to 123,,winding of relay 118 to ground. Relay 118 operates, in this circuit and closes a connection forrthe starting 'of the switchlO l tofhuntaoyer the {terminal controlled thereby. This circuitwill -be closed from battery, windingoithertart rclaylZ, a matu an ck onta o the at the brush and the first terminal of bank 119. Relay 124 in operating closes an obvious circuit for the stepping magnet 125 which in operating opens the circuit for relay 124. The relay 124 and magnet 125 are now alternately operated and released to actuate the switch 104 to connect its brushes with the terminal of the corresponding banks shown.

The ground connection originally traced from the brush of bank 119 will be supplied to the succeeding terminal of this bank 119 7 for the actuation of relay 124.

As the brush of bank 115 passes over the succeeding terminals the alternating current signal will be supplied from the source 217 through the outer left hand armature and frontcontact of relay 117 and the brush of bank 115 in succession to the sleeves of the lines in the'selected group. which are connected to the terminals of this bank. \Vhen the line connected to trunk T is encountered the alternating current signal will be supplied over the sleeve of this connection through the trunk connector 301 to cause the operation of relay 318. The operation from this time on in checking the number is the same as hereinbefore described in connection with an individual line. In this case, how

7 ever, the operator at B will only know that ating now closes a circuit for theoperation of relay 116 from battery, left hand armature and front contact of relay 126, middle left hand armature and front contact of relay 117, winding of relay 116 to ground. Relax 116 in operating opens the locking circuit for relays 117 and 118 which now release. A circuit is thereby established for returning the switch 104 to normal. This circuit may be traced from the stepping relay 124, armature and back contact of stepping magnet 125, inner right hand armature and back contact of relay 118 to ground at the right hand armature and front contact of relay 126. The switch 104 in returning to normal opens a circuit for relay 126 which now releases.

Although this invention has been illustrated in connection with but a single system it should be understood that this disclosure is merely illustrative of the invention and that it may readily be applied to a number of other systems without departing from the spirit thereof.

What is claimed is:

1. In a telephonesystem, a first ofiice, a second oifice, a subscribers line at the first oflice, an operators position at the second oiiice, means for establishing a connection from the subscribers line to the operators position, means for establishing a second connection from the operators position to the subscribers line, a signal at the operators position and means responsive to the establishing of said connections for actuating said signal.

2. In a telephone system, a subscribers line, an operators position, means for establishing a connection from the subscribers line to the operators position, means for establishing a second connection from the operators position to the subscribers line,

a signal at the operators position, means responsive to the establishing of said connections for transmitting a direct current signal over the second connection to the operators position and means responsive to said direct current signal for actuating said signal at the operators position.

3. In a telephone system, a first and a second ofiice, a subscribers line at the first ofiice, an operators position at the second office, means for establishing aconnection from said subscribe'rs line to said operators position, means for establishing a separate connection to the subscribers line from the operators position, a signal at the operators position, means for applying an alternating current signal through the portions of said two connections located at the first ofiice, and means responsive to said alternating current signal and to the establishing of said connections for actuating said signal at the operators position. 7

4. In a telephone system, a first and a second oifice, a subscribers line at the first ofiice, an operators position at the second oiiice, means for establishing a connection from said subscribers line to said operators position, means for establishing a separate connection to the subscribers line from the operators position, an alternating current signal source, means for applying a signal from said source through the portions of said two connections located at the first oflice, means responsive to said signal and to the establishing of said connections for transmitting a direct current signal over the second connection to the operators position, a signal at the operators position and means responsive to the direct current signal for actuating said signal at the operators position.

5. In a telephone system, subscribers lines,

' ageea sue mann'er if the secondconnection was established to a different subscribers line.

- from which the first connection was established for transmitting direct currentsignal direct current signals.

7. In a telephone system, a subscribers line, an operators position, means for establishing a connection from the subscribers line to the operators position, means for establishing a separate connection trom the operators position to the subscribers hne,

means responsive to the establishing of said connections for indicating at the operators position that these connections have been established, means for automatically releasing said second connection when said indication has been given at theoperators position.

8. In a telephone system, a subscribers line, an operators position, means for establishing a connection from the subscribers line to the operators position, means for establishing a separate connection from the opcrators position to the subscribers line, a signal at the operators position, means responsive on the establishing of the second connection for actuating said signal and for automatically releasing said second connection and means for maintaining said signal actuated after the second connection has been released.

9. In a telephone system, a subscribers line, an operators position, means for estabishing a connection from the subscribers line to the operators position, means for establishing a separate connection from the operators position to the subscribers line, a signal at the operators position, means including two relays responsive on the establishing of the second connection for actuating said signal and for releasing the second connection.

10. In a telephone system, a group of subscribers lines, an operators position, means for establishing a connection from a subscribers line to the operators position, means for establishing connections from the operators lishin position to the'subscribers linesinsaid'group in succession, a signal at the operators po sition and means responsive to the estabg *of said connections for actuating said signals 1:1. Inat'elephone system, agroup 'of'subscribers lines,.a:n operators position, means for establishing a connection from a subscribers line to the operators position, means for establishing connections from the operators position to' thiesubscribers lin'es'in' said group in succession, a signal at the operators position, meansresponsive to the establishing of said connections for transmitt-ing over-a-connection from the op erat'ors position a direct current signal-to the operatofis position, and means responsive-to said direct current signal for actuatings'aid signal at the op-e-rators position.

12. In atelephonesystein, a first'ofiicaa second office, a group of subscribers lines at the first ofiice, an operators position at the second ofiice, means for establishing a connection from any one of the subscribers lines to the operators position, switching means"; controllable from the operators position for cstablishingaconnection from the operators position to agi'oup of terminals connected to the sleeve conductors of said lines; means for actuating said switching means to hunt" over said sleeveterm'inals in response to the establishing of thesecond connection to said group, switchingmeans controllable from the operators position for'establishing a third connection from thesecond connection to thence sleeve conductor 'ofthe'first connection at the point wherethis first connection leaves the first:ofiice,tmeans-for applying an alternating current signal "over the second connection to V the sleeve conductor of the subscribers lin'e" i from which the first connection was estab 'lished through thesleeve conductor ofthis connection and back over'the third connect-ion, means responsivetothe reception of said alternating curi'ent'signalover thetli'ird n connection and to the establishing of the second connection fortransmitting a direct current signal over the second connection to the operators position, a visual signal at the operatorsposition and means "responsive to said :directcurrent signal for actuating said visual signal.

13. In atelephone system, groups o'fsubscribers. lines, an operators position, means for establishing a, connection fronian'y su'b- "1 scribers line to the operators position, means for establishingconnections from the operators position, to subscribers lines in succession in any one of'said groupsof lines,

a signal at the operators position and means "3'25 for actuating said signal iii-one manner it said connection from the operators position is made to subscribers lines of the group from which the first connection was estab lished and for actuating said'si'gnal iiia dif- T39 ferent'manner if said connection from the operators position is made to subscribers lines in another group.

14. In a telephone system, a group of subscribers lines, an operators position, means for establishing a connection from a subscribers line to the operators position, means for establishing connections from the operators position to the subscribers lines in succession and for releasing said means after a connection has been made to the last .subscribers line in the group, and means responsive to the establishing of said connections for indicating at the operators position that the first connection has been made.

15. In a telephone system, groups of subscribers lines, an operators position, means for establishing a connection from the operators position to a point representing a group of lines, a switch responsive on the selection of said point for hunting over the subscribers lines in said group, a signal at the operators position and means responsive to the establishing of said connections and to the hunting operation for actuating said signal.

16. In a telephone system, groups of subscribers lines, an operators position, means for establishing a connection from the op erators position to a point representing a group of lines, a switch responsive on the selection of said point for hunting over the subscribers lines in said group, a signal at the operators position, means responsive to the establishing of said connections and to the hunting operation for transmitting over the connection from the operators position at direct current signal to the operators position and means responsive to said direct current signal for actuating the signal at the operating po sition.

17. In a telephone system, a first and a second ofiice, a subscribers line at the first oifice, an operators position at the second ofiice, means for establishing a connection from the subscribers line to the operators position including a sleeve connection from the subscribers line to the point of the first connection where it leaves the first oflice, means for establishing a separate connection from the operators position to the sleeve of the first connection at the subscribers line, means for establishing a connection between said second connection at the first office and the other end of the sleeve, means for apply- 18. In a telephone system, subscribers lines, an operators position, means for establishing a connection from a subscribers line to said operators position, means for establishinga connection from said operators position to a subscribers line, a signal at said operators position, means responsive on the establishing of said second connection if it was established to the same subscribers line from which the first connection was established for transmitting a continuous direct current signal over the second connection to the operators position, means responsive to the establishing of said second connection if it is established to a different subscribers line to the one from which the first connection was established for transmitting an interrupted direct current signal to the operators position, and means responsive-to the continuous direct current signal for continuously operating the signal at the operators position and for intermittently actuating the operators signal in response to the interrupted direct current signal.

19. In a telephone system, a subscribers line, an operators position, means for establishing a connection from the subscribers line to the operators position, means for establishing a separate connection from the operators position to the subscribers line, and a relay responsive to the establ shing of the second connection for releasing said second connection.

In witness whereof, I hereunto subscribe my name, this 25th day of November 1930.

RALPH L. QUASS.

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