US1540786A - Telephone system - Google Patents

Description

June 9, 1925. 1,540,786

' c. E. LoMAx TELEPHONE SYSTEM 2 Sheets-Sheet l` Filed Jan. 1I. 1923 Y 'flamenca E- Lmmax Jurle 9, 1925.`

cQE. LoMAx l l TELEPHONE SYSTEM A Filed Jan'. 11. 1923 2 sheets-Sme:l 2

-rmusi-LIDL Elsner-rae ELE/'max Patented' Janav 9, 1925.

A1.1151111515 STATES 'emulator-Flos.

CLARENCE Lomax, OEl CHICAGo, ILLINOIS, nssIefNOn To AUTOMATIC ELECTRIC 1 COMPANY, or CHICAGO, ILLINoIs-A CORPORATION OE ILLINOIS.

. TELEPHONE .sYsTEim Application led January 11, 1923. Serial No.' 611,916.

To all whom it may concern:

vBe it known that I, CLARENCE E. LOMA-x, a citizen'ot the United States of America, land a resident of Chicago, Cook. County, and State of Illinois, have invented certain new andusei'ul Improvements in .Telephone Systems, of which the Jfollowing 1s aspeci-4 ication.

The present invention relates in general to telephonev systems in which connections may be established through the medium of vsubscriber controlled lselector and connector switches, but is more particularly concerned with a' system of the above character which is combined with or has superimposed on it, so to speak, a watchmans service system; and the object of the invention may be the switchhook.

said to be, broadl. the provision of new and improved auxiliary apparatus for use in connection with a telephone system.

In the preferred embodiment of the invention', means are provided whereby certain telephones in the system may be used as watchmans ,stations in addition to performing the funlctions usually ascribed to a telephone in an ,automatic system.' When used as a watclimans station the receiver-of a given telephone is'removed and a certain digit dialed in the usual manner, the re ceiver then'being immediately restored to As a result lof the foregoing a' visual signal is produced 'at' the supervisory board indicating that a watchman has called in from a certain station, and in addition a permanent record is made of the station number and the time of calling.

A special object of the invention is. the provision of means which insure that a watchman must call-in from the various stations in prescribed order.

Another special ob'ect is the provision of means which will bring in an alarm at the supervisory board should a predetermined interval of time elapsel between the calling in r from a given station and the calling in from the next station on the route. Further means are provided to bring in an additional alarm at a distant Otlice, police headquarters for instance, should a yet longer predetermined time interval elapse before the call-in is made from the next statlon in the route.

These objects, together with others which will not be specifically pointed out now, will be more fully pointed out hereinafter, refer- 'ence beinghadx to the` accompanying drawings, Figs. land 2, which show by means of the usual circuit diagrams sutlicientv of bodying the principles ofthe invention to enable the same to be understood. Fig. 1

the apparatus employed in a system em.

to establish a connection between a calling 1 station A and a called station A', whilel Fig. 2 shows the auxiliary equipment of the watchmans service.

Referring to the drawings, the automatic stations A and A', Fig. 1, are ordinary automatic stations having the usual talking signallin and impulse sending instrumentalities. at the supervisory board and is normally he telephone A2, Fig. 2, is located.-

connected through the key K to the line switch C2; this telephone is identical withA telephones A and A. The telephone A is .located ata distant office, police headquarters for instance, and may be considered as being similar to telephone A, except, in view of the fact that as it is used onl to receive iincming calls, it is not provi edwith a The line switches C and C', Fig.' 1, and

C2, Fig. 2, are mechanically of the well known vrotary type in which the' wipers have no normal position and move in a forward direction onl The selector E, y the well known vertlcal and rotary typein which the bank contacts are arranged in horizontal rows or levels.

. The connector switch denoted by the dotted rectangle I-I, Fig. 1, is also a switch of the vertical and rotary type.

The holding bridge D, Fi 2, is one of a number of such bridges whlch are seizable by the selector E when the wipers of the said selector are raised to the ninth level of bank contacts. tended to the holding bridge I) battery is i 1, is mechanically of- When a connection is exel supplied to the calling subscriber by the line'I 1.00

relay 117, while a holding ground is pro-- vided by release relay 118.

A relay, such as the relays R', R2, or R50, Fig. 2, is associated with each line switch whose telephone is to be used as a watchmans stat-ion, the association bein such that the relays R, reading from right to left, will correspond with the watchmans stations in the order of their operation as determined by the watchmans route.

A magnet, such as the magnet M', M2 or M", is associated with each of the rela .s R, andindirectly, with eachof the watc mans stations. Each magnet is provided with an armature which may serve to perorate or mark av continuously moving tape in order that a permanent record may be made of the station number and the time of calling.

The thermostats T and` T, Fig. 2, are provided in order to obtain a slow step by step operation of the switch S.

The switch S, Fig. 2, is a step by step rotary switch of the type in which the wipers move in a forward direction only. In further explanation of this switch it should be stated that it is of ythe type in which the wipers are advanced when the stepping magnet retracts its armature rather than when the stepping magnet is energized.

The system having' been described 1n general, a detailed description will no-w be given of its operation, and for this purpose it will be assumed that the subscriber at station A,

Fig. 1, desires to call station A', Fig. 1, whose number is assumed to be 236.

When the receiver is removed at the callt ing station, a circuit is closed over the line oft conductors 11 and 12 for the line relay 13 of the line switch C. Line relay 13, upon energizing, closes at armature 1 4 a circuit for switching relay 15 and stepping magnet 16 in series, and at armature 117 connects the test wiper 20 to a point in the circuit between the switching relay 15 and the stepping magnet 16. From thispoint the operation depends upon whether the trunk .line upon which the wipers of the l1 ne switcli are standing is busy orA idle. If 1t 1s busy there is aground potential on test 'contact 23, switching relay 15 is short circuited, and

the stepping magnet 16 whichinterrupts its own current is operated in the manner of a buzzer to advance the switch wipers step by step in search of an idle trunk line. In the present case. however, we shall assume that the trunk lline uponwhich the wipers of the line switch are standing is idle. That being the case, switching relay 15 is notshort circuited and stepping magnet 16 is not energized onaccount of the high resistance of switching relay 15. Switching relay '15, however, is energized and at ar1na ture 29 disconnects the test wiperf20 from the oint between its own winding and that lie stepping magnet 16 and connects it to the grounded private 'normal conductor 30. As a further result of the energization of switching relay 15 it. disconnects the line conductors 11 and 12 from the winding of rela 13 and ground, respectively, and exten s them by way of armature 31 and 32 and their Working contacts, wi ers 18l and 21,`bank contacts 9 and 24, trun conductors and 28, armatures 33 and34 and their resting contacts to the upper and lower windings of the line relay 35 of the selector E. Line relay 35 now energizes on the calling subscriber s loop and at 1ts armature 36 closes a circuit for the slow acting release relay 37. Release relay 37, upon energizing, opens a point in the circuit of release magnet 38, prepares a circuit for relay 39 at armature 40, and at armature 41 places ground upon release trunk conductor 42, thereby establishing a holdingcircuit for the line switch C. By means of this ground potential on test contacts 23 and vits multiples in the banks of the other line switches which have access to the selector E, the seized trunk line is maintained busy in the usual mannei. Abranch of circuit extends by wa of private normal conductor to multiple test contacts in the banks of the connector switches having access to the calling line, thereby guarding 1t against intrusion inthe usual manner. It may be mentionedthat a further result of the energization of the switching relay 15 was the extension of the recording conductor 8 by way of armature 45, wiper 19, Abank contact 22 to conductor 26.

r1`he calling subscriber nowoperates his calling device inf accordance with the first digit 2 of the desired number thereby producing two interruptions in the circuit of the line relay ofathe first selector E.- As

soon as line relay. 35 deenergizes in responsel to the first of these interruptions a circuit isclosed which is traceable from ground at armature 46, armature 36 and its resting contact, armature 40 and its workin contact, winding of the series relay 39, winding' this holding of the vertical magnet 47 to battery. -Vertical magnet 47, upon energizing, raises the wipers 48, 49 and 50 opposite the first level of bank contacts, whereupon the off normal springs 52 close and complete va circuit traceable from the grounded release trunk conductor 42 by way of armature 57 and its working contact (rela-y 39 having energized), ofi" normal springs 52, armature 58 and its resting contact, winding of relay 53 to battery. Stepping relay 53, upon energizing, closes a point in the circuit of rotary magnet 54 at armature 55 and at armature 56 closes a locking circuit for itself independent of 'relay 39. When the line relay 35 deenergizes in response to the second interruption produced in its circuit, the vertical magnet is again operated' to raise the deenergize and vclose a circuit thro h the.`

rotary magnet 54 at amature 57. otary magnet 54, upon energizing, advances the wipers 48, 49 and 50 into engagement with the first set of contacts in the second level, and at armature 58 opens the circ'uit ofstepping relay 53. Stepping relay 53, upon 'de-` energizing, vopens another point in its circuit, and at armature 55 opens the circuit of rotary magnet54. Rotary'magnet 54, upon decnergizing again closes the contact at artact, o normalsprings 52, armature 58 Vand its resting contact,fwinding of -relay 53 to battery. Stepping relay 53, upon energizing, closes a'locking circuit torlitselt at armature 56 and at armature 55 again completes the circuit of rotary magnet 54. This 'alternate operation of the, stepping relay and rotary magnet continues so long as ytest 'wi er 49 engages grounded contacts. In

this case we will assume-that' the trunk line comprising conductors 108, 109-and 111 is the one first found to be idle. y lThat being the case, 'whenthe wipersofsfele'ctor E arrive u pon the bank contacts 62, 63 and 64 there issno ground pote'ntialontest contact 63 and consequently steppjiiigrelay 53 doesv not energize. With 'this-fv'conditi'on existing switching relay 59 energizes over the follow-` ing circuit: from ground by way of release trunk conductor 42, switching relay59, off normal. springs 52, armature 58-and its resting contact, 4,Winding of relay 53 to battery.

Stepping relay 53, however, does not ener-l gize over this circuit von account oi the relatively high resistance of switching relay 59. Relay 59, upon energizing, removes ground from armature 40 of release relay 37 at armature 46, disconnects test wiper 49 'from the point between switching relay. 59 and stepping magnet 53 and' connects it` to ground by way of.l release trunk conductor 42 at armature 61, .thus making theseized trunk busy immediately; and at armatures 33 and 34 disconnects the trunk conductors 25 and 28 from the windings of line relay 35 and extends them by way of the working contacts of these armatures, wipers 48 and 50, bank contacts 62 and 64, trunk conduc.

GO tors 108 and 111 to the lie relay of the connector l-. Connector H therefore laces ground u on the' release trunk con uctor 109, there y establishing'the usual holdin circuit for theselector E and the line switc C beforethe slow actingrelease relay. 37 of selector E has had time to de energize.-

When thecalling subscriber dials the second figure-f3 of the called number, the connector H will raise its wipers to the third' level ofubank contacts. The calling sub-A scriber now Adials lthe final fi ure-6 of t-he called number, as a result o which the .connector rotates into connection with the line extending its wipers six steps to the station.- A. Upon the completion of the connection. to the called line a signalling circuit is established in the connec- -tion in the usual manner and the bell at the completed the calling subscriber will .re-

'place his receiver, bringing about the release of the connection` in the usual manner.

The attendants telephone A is available for telephone service to the otherstations of the system, A for example, when the key K is in its normalposition. Removing the receiver of A2 actuates the line switch C2, in a manner heretofore described for line switch C, to extend the line to a selector such as E, from which the call proceeds in `the well known manner.

An explanationiof the normal operation ofthe watchmanssystem will now be given, it being assumed that station A., Fig. 1, is the first station on the route. When the watchman removes the receiver at station A the line switch C will operate in the usual manner to extendthe connection to a first selector, it being assumed that selector E is the one'first found to be idle. The Watch man now dials the ligure 9, and as a result thereof the selector E raises the wipers 48,

l49 and y50 opposite the ninth level of bank ico 2, to battery and ground, respectively. The y line relay 117, upon energizing, closes the circuit of release relay 118 at armature 119; the latter relay, upon energizing, places ground Vupon the release trunk conductor.

113 at armature 120, thereby establishing the usual holding circuit for the' selectorl E and the line switch C. A furtherresult of the energizat-ion of the relay 118 is the A closing` of' a `circuit, from ground at armature .121, resting contact and armature 122, winding of; relay 123 to battery. Relay 123, upon .energ1z1ng, opens its own circuit, and

`as armature 121 remains' operated. The

operation of relay 123` producesa tone which is placed on the negative line by `way of armature 122, condenser v124, armature 125 and its resting contact and conductor 112. This tone is audible in the receiver at sub-- station A and advises the Watchman that his call-in has been recorded. The watch' man then restores his receiver, and as a result, the release of the switches involved in this connection takes place in the usual manner.

Returning to a consideration of selector E at the time of the euergization of switching relay 59; the above mentioned operation results in the deenergization of line relay 35 followed after a time by the release of the slow acting release relay 37. During themterval of time elapsing between the energization of relay 59 and the deenergization of relay 37 a circuit may be traced as follows: from ground at armature 46 of relay 59, and its working contact, armature 7l and its Working contact, springs 72 which are closed by the shaft only when raised to the ninth level, conductor 26, bank contact 22,

wiper 19, working contact and armature 45,

conductor 8, lower winding of relay Rf, Fig. 2, winding of magnet M', upper winding of relay 126 to battery. As a result of the short impulse of current over the above traced circuit, relay 126- will energize only momentarily, the locking circuit of its lower windin being open at the wiper 130 as the' switch is at this time in normal position. The before mentioned impulse of current will also cause a momentary operation of magnet M', resulting in the production of a permanent record of the number of the station calling and the time of operation. As a further result of the short impulse of current -over the above traced circuit, relay R will energize andclose a locking circuit for its upper winding in series with marginal relay 146, by way of armatures 127 and 128. It is to be noted that armature 127 is associated with .the next Relay R also closes the 'circuit of lamp L at armature'129, the lamp L indicating to the supervisor that the watchman has called in from station A. The marginal relay V146 is so adjusted that it will not operate at this time. wA further result of the energization of relay R is the closure of acircuit through relay 179 at armature' 131. Relay 179, upon energizing, closes a locking circuit for itself by way of armatures 132 and 133;, thus becoming independent of the further operation of relay R. It is to be noted that armaturei132 is associated with the last R relay in the group; relay 179 will, therefore, remain energized until a call-in is made from the last station on the route. A fur ther result 'of thel energization of relay 179 136 throu 4terval of time,

R relay in the group.-

may be traced from the grounded conductor gh the winding 141 of thermostat T to battery. After a certain interval of time the winding 141 will heat up and, at armature 142, will cause the closure of a circuit through .winding 143 of thermostat T. After a certain interval of time, winding 143 will heat up and close a circuit through relay 145, the said circuit being traceable from groundat armature 134 and itsworking contact, winding of relay 145, armature 144 and' its working contact to'battery. Relayl 145, upon energizing, removes ground from conductor 136, thus opening the circuit of winding 141 of thermostat T and of the stepping magnet 139 of-switch S. The deenergization of the stepping magnet 139 causes the wipers 130 and 140 to be advanced into engagement with the first contacts in their respective banks. After a certain interval of time, thef-winding 141-will cool oft' and open the circuit of winding 143 at armature 142. Windin 143, after a certain interval of time, wil in turn vcool oif and open the circuit of the slow acting relay 145 at armature 144. After a certain inrelay 145 will deenergize and again close the` circuit of winding 141 and of stepping magnet 139, whereupon the stepping magnet will again energize, and the Winding 141 will again heat up thus starting 'the cycle of operations over again. From the foregoing it will be seen that, so long as the relay 17 9 remains energized, the thermostats T and T will serve to actuate the stepping magnet 139 in such a way thatthe wipers 13 0 and 140 will be slowly rotated stepby step over the contacts in their respective banks. g

' The-normal operation of the system req uires that the Watchman callin from the second station on the route before the wiper 140-reaches the seventh contact in its bank.

In further explanation, we may assume` that station A', Flg. 1, is the route. When the receiver at station A connection. As previously explained in connection with selector E, we know that a short impulse of currentwill iiow over the watchmans conductor 7 associated with line switch C, Fig. 1, through the lower wind ingof relay R2, Fig. 2, winding of magnet M2, upper winding of relay 126 to battery. Relay R2 will operate in response to this short impulse of current and open the locking circuit of relay R., at armature 127, at the same timeclosing a locking circuit for itseltin series with the marginal relay 146 at armatures 147 and 148, the latter armature being associated with the next R relay in the series. The marginal relay 146 is so adjusted that it will not .operate at this time. A further result of the energization of rela R2 is the closure of a circuit through lamp 2 at armature 149, thus indicatlng to the' supervisor that the Watchman has called in from the second station on the route. The only result of the deenergizationof relay R is the opening ofthe circuit of lamp L at 4armature 129. The above mentioned short impulse of current will also cause the magnet M2 to operate in the usual manner to produce a permanent record of the number of the station calling and the time of operation. lA vfurther result of the above mentioned short impulse of current is the Yoperation of relay 126, which, upon energizing, closes a locking circuit for its lower winding which may be traced from ground at armature 134 and its working contact, armature 15.0 and its working contact, armature 151 and. its working contact, resting contact and armature 152, multipled contacts in the bank associated with wiper 130, wiper 130, armature 153 and its working contact, working contact and armature 154, lower winding of relay 126 to battery. A branch of the above circuit may be traced from the grounded multipled contacts in the bank associated with wiper 130, wiper 130, interrupter contact 155, winding of stepping relay139 to battery. Because of the fact that relay 126, upon energizing, removed the conductor `136 from connection with the stepping magnet 139 at armature 137, the said stepping magnet may be considered 4to be at normal when the above traced circuit is established, and

yas a vresult 'the stepping magnet now operates in the manner of a buzzer to advance the wipers 130 and 140 step by step rapidly over the associated bank contacts. The automatic rotary circuit is broken when the wiper 130 leaves the last contact in the bank, as is also the circuit of the lower winding of relay 126. The latter relay, upon deenergizrng, again connects the conductor 136 with the steppingmagnet 139 at armature 1,37. Since relay 179 is still in an operated position the thermostats T and T will again function to'cause the magnet 139 to slowly advance the wipers 130 and 140 step by step mentarily, but will not lock up as the circuit of its lower winding is'open at armature 153 dueI to the deenergization of relay 179, as will be explained hereinafter. The magnet M50 will operate inthe usual manner to make the permanent record while relay R0 operates and forms a locking` circuit for its upper winding in series with the marginal relay 146 at armatures 156 and'157, the latter armature being associated with the rst R rela A further result of the energizacuit of the upper winding of the preceding R relay and the closing of the circuit of lamp L50 at armature 158.V A still further result is the opening of 'thelocking circuit o f relay 179 at armature 132. The latter relay, upon deenergizing, opens the circuit of the lower winding of relay 126 at armature 153, therefore relay 126 cannot be depended upon to bring about the advancement of switch S to its normal position. For the above reason provision 1sl made whereby 'the deenergi'zation, of relay 179 closes a vcircuit traceable from ground at armature 134 and its resting contact, resting contact. and armature 152, multipled contacts in the bank associated with wiper 130, wiper 130, interrupt/er contacts 155,

,winding of stepping magnet 139vto battery.

rlhe magnet 139 will operate over the above traced circuit in the manner of a buzzer to rapidly advance the wipers 130 and 140 to their normal posit-ion, the automatic rotary circuit being broken when wiper 130 leaves the last contact in its bank. As the relay 179 is now deenergfized lthere will be no further operation of the thermostats, and consequently `no slowy motion imparted to the wipers of switch S. Y

lt may be mentioned that the relay Rfo will vremain locked up4 through armature 157, relay R', until the watchman again calls in from the iirst station on. the route. There is, however, no prescribed time interval within which the call-in frornthe first station on the route must follow the call-in from the last station. v

vAn explanation will now be given of the alarms produced should there be a delay of longer duration than the prescribed time intion oJ relay R5 is'the opening of the cirlui) lit)

'When the wi er 140 engages the seventh contact in its ank, a circuit is closed which ma be traced from ground at armature r134 an its working contact, armature 150 and its resting contact, conductor 159, wiper 140 in engagement with the seventh bank conf tact, winding of relay 160 to battery. Relay 160, upon energizing, forms a locking circuit for itself from the grounded conductor 159 by way of armature 161, thus becoming independent of the'wiper 140; and furthermore closes the circuit of buzzer B at armature 162. The supervisor, upon hearin the buzzer, will realize that the next calgl-in is overdue, and will glance at the lamps L to determine the location `from which the last call was made. `We will assume he then goes to the assistance of the watchman. The operation of the switch S continues in the usual manner, and if the next call-in is made `before the wiper 140 reaches the twenty-first contact in its bank, the relay 126 will operate 'as usual to cause the switch S to advance vits wipers to normal position, at the same time opening the circuit of relay 160. The latter relay will then deenergize and open the circuit of the buzzer B, the operation of the switch S continuing in the usual manner. If the wiper 140 reaches `the twenty-first contact in lts bank before the next call-in is made, a circuit is closed which may be traced from grounded conductor 159, wiper 140 in engagement with the 'twenty-first contact in its bank, winding of relay 162 to battery. Relay 162, upon energizing, will form a locking circ cuit for itselffrom -grounded conductor 159- lby way of armature 163, and thus becomesv independent of the further advancement of wiper 140. v-A further result o f the energization of relay 162 is the placing of current from the generator G, by way of armatures 165 and 166, and armatures 167 and '168 and their respective resting contacts, upon conductors 169 and 170, thus causing-the ringer f at station A? to be operated. The attendant at station A3, presumably olice headquarters, will immediately sendp a patrol to investigate the watchmans system associated with station A. The operation of the switch S continues in the usual manner, and

l when the next call-in is finally made the relay 126 operates in the usual manner to cause the switch S to advance its wipers to normal position, at the same time causing the release of relays 160 and'162 by removing ground from conductor- 159. Relay 162, upon deenergizing, removes enerator from conductor 169 and 170, and7 thus the operation of the ringer at station As call.

willcease as a notiication to police headquarters that the normal operatlon of the watchmans system has been resumed.

1 explanation will now be given of the operation should an error occur in the order in which the stations are called. Under nor- -mal operation the call-in `from each station causes an R relay to unlock the next preceding R relay, thus the current liow through the mar inal relay 146 is such that the said relay wi l not operate. 'If an error is made and one or more stations are passed the next call-in will operate an R relay, but the R relayc so 'operated will Vbe unable to release the relay locked up by the last preceding drawing current through relay 146, and this relay will now energize and'open the lock. ing circuit of relay,126 at armature 152. There will,- therefore, be noA ground on the multipled contacts in the bank associated with wiper 130, and the switch S will -continue to operate under the control of the thermostats. When wiper 140 engages the seventh contact in its bank the buzzer B will operate to attract'th'e supervisor-s attention. The supervisor will see that two L lamps are lighted and, will realizepthat an error has been'made in the order of calling in from the stations. The supervisor will then get in touch with the watchman, who will go back to the station that was overlooked and call-in from each station in order. When only one R relay remains energized, therelay 146 will deenergize causing the normal operation of the system to be resumed. If `this has been accomplished before the wiper 140 reaches the twenty-tiret contact in its bank, no alarm will be given station A3; otherwise, relay 162 will operate to ring station yAs as previously explained.

An explanation will now be given of the means provided whereby the supervisor may talk to the watchman at any station or to the attendant at station A. The supervisor may operate the non-locking key K? to impress generator u on station As by way of' armatures 167 an l168, and conductors 169 and 170, the operation of key K2 referably takingthe form of a code ring to istinguish it from the ring produced by relay 162. The attendant will then operate the nonloeking key K of relay 173 and connect station A2 with station Aa through talking condensers 171 and 172. The station A 'is now disconnected from the line switch Cz and receives its talking batte lay 174. tation A3 receives its talking battery through the two windings of relay 175,v by working contacts and armatures 167 and 168, and conductors 169 and 170. Upon the restoration of the non-locking key K to normal, the circuit returns to normal.

If the supervisor desires to talk to the As a result, two R'relays are now which will close the circuit through the two windings ofrcv Watchman the next time he calls inthe non-y locking key K is operated, talking batte-ry being received through rela 174 as before. It should be noted that 3 is connected to A2 by means of relay 173 When the attendant operates K to talk to the watchman. A3, ho-Wever, is not signalled in this instance since the attendant-has not operated K2. By this arrangement the police station A3 may listen in on the conve-rsation between thev attendant and watchman.

When the Watchman calls in the relays 117, 118 and 123 of the holding bridge D will operate as previously described.` The tone produced by relay 123 will not pass to the t negative side of the line because of the open dit circuit at armature 125 of relay 174. The absence of the accustomed tone will indicate to the Watchman that the attendant is Waiting to talk to him. The conversation will be carried onv through the talking condensers 177 and 178. The restoration of 'the non-locking key K', and of the receiver at the calling station, Will cause the return of the apparatus toits normal position.

The object and scope ofthe invention having been described, What is considered to be new and whatit is desired to have protected by Letters Patent will be pointed out more specifically in the appended claims.

What I claim is: l, f

1. In a combined telephone and Watchmans service system, a plurality of outlying stations, a central station, means o-perable by the Watchman atthe outlying station to extend talking connections therefrom to said central station in a definite order, and means responsive to the Watchmans call for sounding an alarm at the central stationI if the Watchman calls in from one of said outlying stations out of its regularturn.

l2. In a combined telephone and Watchmans service system, a plurality ot reporting stations, a central station, means operable by the Watchman at the outlying stations to extend talking connections-therefrom to said central station in a definite order,v a signal at the central station and means responsive to ythe Watchmans call for actuating said signal in case the watchman calls from one of said stations Without having called infrom the preceding station.

3. In a combined telephone and Watchmans service system, a central station, a plurality of outlying stations, means oper- .able by the Watchman at said outlying stations for extending =talking connections therefrom to said central station in a definite order, and means responsive to the Watchmans call for notifying the `attend- "ant at said central station in case the Watchman fails to observe the prescribed order in which said, outlying lstations are to bc reported from.

4. lIn a combined telephone and watchmans service system, a central station, a plurality of outlying stations which arc used by the watchman in a certain predetermined order to report. to said central station, a signal at the central station for each outlying station actuated when the associated station is reported from, and' a special signal actuated whenever any sta-tion is reported from out of its regular-turn.

5. In a combined telephone andwatch-l mans service system, a plurality of outlying stations, a central station, means operable by the watchman at said outlying stations for extending` talking connections therefrom to said central station at regular t any interval Vbetween successive calls exceeds a predetermined limit.

7. In a combined telephone and Watchmans service system, a plurality'of outlying statlons, a central station which the Watchman calls from said outlying stations at regular intervals, signals at the central station `operated responsive to calls from the outlying stations, and a special signal at the A central station operatedin case any interval between successive calls exceeds a predeterm-ined limit.

8. Ina combined telephone and Watchmans service system, a plurality of outlying stations, a central station which they Watchman calls from said outlying'stations at regular intervals, a signal at the central station and means for operating it in case any interval between Successive calls exceeds a predetermined limit, a third station and signal thereat, and means for operating said last mentioned signal in case the abnormal time interval exceeds a predetermined limit.

9. In a combined telephone and watchmans service system, a plurality of outlying stations, a central station which the Watch-` man calls from said outlying stations at reg.

ularv intervals, means for notifying lthe at' tendant at the -central station in case the Watchman encounters some obstacle which prevents him from calling in from one of said outlying sta-tions on time, another station, and means for notifying the attendantat said last mentioned station in case the de- Mii Fill

layed call is not vreceived within a certain predetermined additional time.

10.`In a combined telephone and Watch'- mans service system, a plurality of outlying telephone stations, a central station, means operable by the watchman at said outlying stations for extending talking connections therefrom to said central station in a definite order, means for notifying the watchman that his call has been registered at the central station, and means responsive to the Watclimans call for notifying the attendant if thel watchman calls from the stations in other than the prescribed order.

11. In a combined .telephone and watchmans service system, a plurality of outlying stations, a central station, means controlled by the Watchman for calling the central station from each outlying station, a signal at the central station for each outlying station, operated when the Watchman 'calls from the associated station, and means forl notifying the watchman in each instance thatthe signal has been operated. p

12. In a watchmans service system, a central station, a plurality ofY calling` stations, means controlled from the callin stations for extending calls to the centra station and operating a signal thereat, an automatic switch at the central station, means controlled by eachl call for starting tle operation of said switch, and means controlled by said switch for automatically op rating a signal after a predetermined time.

13. In a watchmans service S'lystem, a central station, a plurality of cal ing stations, means controlled from the calling stations `for extending calls to the central station and operating a signal thereat, an automatic switch at the central station, means controlled by each call for starting the operation of said switch, means controlled by Said switch for automatically operating `a signal after a predetermined time, and means for preventing the operation of said last signal if another call is received at the central station during said predetermined time.

In witness whereof, I hereunto subscribe` l my name this 4th day of January, A. D., 1923.

CLARENCE E.` LoMAX.

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