US1078229A - Signaling system. - Google Patents

Description

H. G. WEBSTER.

SIGNALING SYSTEM. APPLICATION FILED SEPT. 4, 1906.

Patented NOV. 11, 1913.

R NA .5

UNITED STATES PATENT onrron.

HARRY G. WEBSTER, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO,

KELLOGG- SWITCHBOARD & SUPPLY COMPANY, A CORPORATION OF ILLINOIS.

SIGNALING SYSTEM.

Specification of Letters Patent.

' Patented Nov. 1 1, 1913.

Application filed September 4, 1906. Serial No. 333,148.

To all whom it may concern:

Be it known that I, HARRY G. WEBSTER,

each provided with a transmitting device,

terminate at a central point and are there provided with signal-receiving devices and signal indicators.

It relates particularly to that, class of systems in which the receiving devices are less in number than the circuits and, when op.-

erated, will control indicating devices adaptnal is sent.

The object of my invention is to provide improved means in such a system for preventing false signal indications when s1gnals are transmitted over separate circuits simultaneously. I

A further object of my invention is to provide means whereby signals originating on separate circuits simultaneously will be indicated successively at the central point, and whereby signals transmitted on separate circuits simultaneously shall not cause the simultaneous operation of separate indicating devices at the central point. a

In accordance with the preferred form of my invention, I include in each primary circuit a circuit-changing device and so connect the circuits to a central source of current that the operation of the circuit-changing device of any circuit causes the operation of a relay associated with each limb of the circuit. The lines are arranged in interrelated groups, the relay of one line limb being also connected to corresponding limbs of other circuits; and the relay associated with the other line limb, being connected with corresponding line limbs of still different circuits. The remainingline limb of one of the first-mentioned other circuits is connected to a third relay, and the remaining line limb of one of the last-mentioned other circuits is connected to a fourth relay, each of the last two mentioned relays being likewise connected to other line limbs. The

relays are arranged in two groups of equal number, those in one group being connected to the active terminal of the battery, and those in the other group being connected to the ordinarily grounded terminal of the battery. When, therefore, the circuit-changer of any primary circuit is operated, one relay in each group will respond as a pair, and the simultaneous operation of any pair of relays causes the operationof a signal indicator responsive only to the operation of that pair. By this arrangement, it is possible to make a given number of relays answer for a number of lines equalto the second power of the number ofrelays in a group; but in order. to prevent interference,

. should a number .of circuits be transmitting ed to indicate the circuit from which a sigrelay in the series has its winding connected 4 to battery through contacts of all-relays preceding it in the series, and any relay when operated willinterrupt the battery connection of the windings of those relays subsequent to it in the series. It therefore follows that that line,- which operates the first relay in each group, takes precedence over, or is in preceding relation to, all other lines; and that all other lines are in subsequent relation to that line. l

My invention will be more fully understood from the accompanying drawing, illustrating its application to two wellkno-wn telephone exchange systems.

Referring to the drawing, the primary circuits are indicated at the left as lines extendlng to various subscribers stations.

The receiving devices are the relays A, B, C

1, and torelay 3 through ,these contacts and corresponding contacts of relay 2. Relays 1 and 2 are thereforein preceding relation to relay 3, and relays 2 and 3 are in subsequent" relation to relay 1. The grounded or return side of the battery is likewise connected to relays A, B and 'G in a similar manner, B arein preceding relation to C," andB and C are in subsequent relation to 'Al'; The substation A is provided with the usual A and bell and condenser in Jermanent brid e of the limbs 91 and 92 of the line; and receiver r and transmitter 't are brought into circuit by the elevation of the switch-hook Jt. The limbs 91 and 92 are-connected to the'centr'al ofiice through the moving contacts of the cut-off relay 93, normally in engagement 4 with contacts connected by wires 7 and 8 :to

. calling.

"call, his line will be found to be in preced ing relation to line B of relay A will therefore interrupt the-cirthe windingsof relays Aand 1 respectively,

The normal central oflice connections 0t similar lines are in part indicated at A to C the normally closed contact =points\of:the

cut-ofi relays being connected asshowmeach pair to a difierent pairaof relays, and each pair consists of'one .relay in each group. 'lVhen circuit is closed at the substation voi any line, a difierent pair of -relays in'energized. If, for'instance, circuit :be closed at the substation of line 13?, relay B and relay 2 will be energized. Theenergiza-tion of re.- lay 2 removes ,the battery connection of relay '3 and connects battery to one side of the lamp 13 as well as to the lamps A and C Relay. B, being energized, discon- 17, contacts 1615 of relay 2, lamp B and contacts -1211 of relay 3 to the return side. of thebattery, thus illuminating lamp 13 to indicate that the subscriberon line B is It will benoted that at this time the circuit of lamp B is open .atlcontact 16 of relay 1, .and the circuit of lamp B3 is open at contact 15 of relay 3. Likewise the circuit of lamp A is-closed at relay 2gbut open at relay A,and the circuitof lamp C is closed .at relay 2 but open at relay C. "Therefore,.at this time, no lamp but thatof:

line B is illuminated. If, during the time lamp B is displayed, subscriber A should The 'energization cuit of relay B at contacts 10-.9 of relay Al,

and the operationofirelay 1 will interrupt: the circuit of relay 2 at contacts .1? 14ot relay 1, thus extinguishing lamp B and illuminating :lamp A. r The operator then inserts the answering plug P in the jack j and current will flow from the battery -H 7 through relay'23 of thecord-circuit,strand 35, contact 21 of the plug, contact 5 of the jack 3:, and thence through relay 93 to the return side of the battery, disconnecting limbs 91 and 92 from relays A and 1 and connecting them to contacts 45 of the springjack. Circuit is now closed through relay 28, limbs 91 and 92 to the return side of the battery through relay 22, the energization of relay 22 preventing the illumination of lamp 24. The operator answers in the usual manner and tests the contact 5 of a .springjack with which she wishes to make connection. If the line be busy, current will flow from such contact, through the tip of the plug 0., through strand 32, the normally ,closedcontact of relay 27 and through the test relay 30 to the :return side of the battery. The energization of relay 30 includes the ,test winding of the operators induction .coilSl iii-closed circuit with the central battery, thus niving her the customary-busy indication. .[f the line be idle, thecalling plug-O is inserted, whencurrent will flow from battery H, through relay 27, strand '38, sleeve contact piece of the plug and thence through thecut-oif relay of the desired ,line, thus cutting oil its limbs from .the signal receiving relays with which it is associated. The subscriber is called in the usual manner byoperating the ringing -lrey-88, during which time the cut-cit relay 95 is energized by current through the resistv.ance 36. hen the ringing key is restored,

again closing circuit through relay 27, the

moving contact28 engages its forward con- ;tact, thus completing circuit through the 100 supervisory lamp 25. The moving contact 29 'likewiseengagesits forward contact, thus disconnecting the test relayand completing the circuit of strand 3.2 to :the supervisory relay :26. lVhen the subscriberanswers, the 1 5 consequent energization of relay 2G extinguishes lamp 25 and .the connection is in condition for conversation. As each subscriber hangs ,up his receiver, the deenergization of his relay 22 or 26 illuminates the corresponding lamp; and when both lamps 2a and 25are illuminated, the operatortakcs down the connection.

Referring now ltothe condition of the signal-receiving relays at the time the operator plugs ,in ycircuit. has been closedxthrough the substation of line B but has been in ,terrupted at relays Aand 1 through their energization .over the circuit through line At. When :the answering plug P was inserted, relays A and 1 were thus deenergized and the dropping back of their armatures again completes the circuit for line B through relays 1B and 2. :Lamp B .is .thus again illuminatedand the operator plugs in to the corresponding jack to answer that call. It will likewise be seen that if, prior to the answering of the call'from line 13 the line B had called, relay B would have remained energized, but relay 2 would have been deenergized by the interruption of its circuit at contact 1314 of relay 1. Again,

lamp B would have been extinguished and lamp B illuminated. It is thus seen that line B is in preceding relation to line B This explanation will make it evident that any line is in preceding relation to other lines of later letter and number, and in subsequent relation to all lines of earlier letter and number. In the structure of the drawing, it will be observed that should all or any number of the lines in the system have their circuits closed simultaneously, butone lamp will be illuminatedthat of line A' the circuit of relays A and 1 only being at that time closed. When the limbs of this line are disconnected from they receiving relays by the insertion of the answering plug, the armatures of both relays drop back. If, as they drop back, contacts .1314: of relay 1 engage prior to the engagement of contacts 910 of relay A, relays A and 2 will be immediately energized, causing the illumination of lamp A If contacts 910 engage before contacts 1314:, relays B and 1 will be immediately energized, causing the illumination of lamp B and leaving relays A and 2 inert. If relays A and 2 are the ones energizcd after line A has been answered, the plugging in of the operator will deenergize both of the relays and disconnect line A from the groups of relaysr As their armatures drop back, if the contacts of relay A close first, relays B and 1 will then be energized, illuminating the corresponding lamp; whereas if the contacts of relay 2 engage first, relays A and 3 will be energized, causing the illumination of lamp A and so on. It is thus seen that where circuit is closed through several lines at short intervals, that lamp will be illuminated which corresponds to the line of preceding relation; and that when circuit then be closed through two or more calling lines simultaneously, through the deenergization of a pair of relays previously energized, there may then be two lines of equalirelation. That lamp will then be illuminated corresponding to the one of such lines through which circuit is first closed by the deenergization aforesaid. If subscribers A and B were to call exactly simultaneously, the signal of that line, whose circuit was first interrupted by the operation of the relays, would not be illuminated until after the call of the other line had been answered.

I have indicated at D a line circuit and cord connecting apparatus similar to that illustrated in Patent No. 647,588, issued April 17, 1900. As far as the signal-receiving relays are concerned, the operation of this structure is similar to that of AB, the difference in the line circuit arrangement being that the jack contact 5 is in a wholly local circuit rather than being connected to one of thetalking conductors of the line. The operation of the cord connecting apparatus is described in detail in the patent abovementioned and no further description seems necessary here.

WVhile I have illustrated my invention as embodied in a telephone exchange system, it is obvious that it is applicable to other signaling structures and I therefore do not wish to be limited to this particular embodiment.

It will be understood that theseveral batteries H, H and H of the diagram may be one and the same and that the several grounds indicated are the return side of the battery or the office return.

It is also evident that various means, other than lamps in local circuits, may be employed for giving the signal indication,

and that many modifications may bemade in the invention without departing. from its spirit.

What I consider new and novel and desire to secure by Letters Patent of the United States is 1. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices each common to a portion only of said circuits, signal indicators controlled by said receiving devices, and means for preventing a false operation of said indicators when any plurality of said transmitting devices are operated at substantially the same time.

2. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices each common to a portion only of said circuits, signal indicators controlled by said receiving devices, and means for preventing a false operation of said indicators when all of said transmitting devices are operated at substantially the same time.

8. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices each common to a portion only of said circuits, signal indicators controlled by said receiving devices, and means whereby any two of said transmitting devices may be operated at substantially the same time without causing the simultaneous operation of any of said indicators.

L. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices each common to a por tion only of said circuits, signal indicators controlled by said receiving devices, and means whereby signals may be transmitted from any two ofsaid circuits at substan- .tially the same time without causing the ,sinultaneous operation of a plurality .01"? indicators.

r A signaling system comprising a plurality of primary controllingjcircuits, a signal transmitting device for each circuit, signal receiving devices eachcommon to a portion only .of said circuits, signal indicators controlled by said receiving devices, and

[means whereby signals may be transmitted from. any, tWo of said circuits at substantially the same time and the operation of .the indicators to be so delayed as .to cause them to operate successively.

.6. A signaling system comprising a plurality of primary controlling c rcu ts, a sig nal transmitting device foreach circuit, signal receiving devices each common to a portion only otsaid circuits a signal indicator for each circuit controlled by said re- 1 .ceiving devices, and means whereby signals maybe transmitted from any plurality of said circuits at thesame time without causing the operation of indicators associated with idleci-rcuits.

7. A signaling system comprising a .pl-uralityofprimary controlling circuits, a signal transmitting device for .e1(3 l1 Cl,-ECtllt, S lg nail receiving devices .each common to a por- .tion only of said circuits, signal ind cators controlled by said receiving devices, and

.means whereby the indicating devices will respond successively when all of said trans-- .mitting devices are operated at the same 9. A. signaling system comprising a plu- 'rajlity .of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices less in number than said circuits eachcommon to a portion only of said .circuits,a signal indicator for .each

circuit controlled by said receiving devices,

. and means for preventing a false operation said of said indicators when any plurality ,of I ransmitting devices are operated at substantially the same time.

.10. A signaling system comprising a pinralityof primary controlling circuits, a signal .transm ttingdevice for .each circuit, signal receiving devices less in number than said circuits eachcommon .to a portion only of said circuits, a signal indicator for .each' circuit controlled by said receiving devices,

and means for preventng a false operation ofsaid indicators when all of said ztransmitting devices are operated atsubstantially the same time.

11. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices less in number than said circuits each common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices, and means whereby any two oi said transmittin devices may be ope at/ed at substantially the same time without causing the simultaneous operation of any of said indicators.

1-2. A signaling system comprising a plurali-ty of primary controlling circuits, a signal transmitting device for each circuit, sig nal receiving devices less in number than 7 said circuits each common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices, and means whereby signals may be transmitted from a plurality of said circuits at substantially the same time without causing the simultaneous operation of a plurality of indicators.

13. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices less in number than said circuits each common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices, and means whereby signals may be transmitted from a plurality of said circuits at substantially the same time and the operation of the indicators be so delayed as to cause them to operate successively.

14. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receivingdevices less in number than said circuits each common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices,

and means whereby signals may be transmitted from any plurality of said circuits at the same time without causing the operation of indicators associated with idle circuits.

15. A signaling system comprising a plurality of primary controlling circuits,

a signal transmitting device for each circuit,

signal receiving devices less in number than said circuitseach common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices, and means whereby the indicating devices may respond at diiferent times when a pluralit-y of transmitting devices are operated at the same time.

'16. A signaling system comprising a plurality of primary controlling circuits, a signal transmitting device for each circuit, signal receiving devices less in number than said circuits each common to a portion only of said circuits, a signal indicator for each circuit controlled by said receiving devices, and means whereby the indicating devices will respond successively when all of said transmitting devices are operated at the same time.

17. A signaling system comprising a plurality of transmitting devices arranged in groups, receiving devices common to said transmit-ting devices, primary controlling circuits connecting the receiving and transmitting devices, signal indicating devices normally controlled over the primary circuits, means for dissociating any of said transmitting devices from the receiving devices, means whereby the operation of a transmitting device in any group will automatically destroy the control of the transmitting devices of subsequently related groups, and means whereby the dissociation of said transmitting device from the receiving devices will restore said control of said other transmitting devices.

18. A plurality of transmitting devices arranged in serially related groups, receiving devices common to said transmitting devices, primary controlling circuits connecting the receiving and transmitting devices, signal indicating devices normally controlled over the primary circuits, means for dissociating any of said transmitting devices from the receiving devices, means whereby the operation of a transmitting device in any group will automatically destroy the control of the transmitting devices of subsequently related groups, and means whereby the dissociation of said transmit-' ting device from the receiving devices will restore said control of said other transmitting devices. y

19. A signaling system comprising a plurality of primary. controlling circuits arranged in inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices, and means for preventing the simultaneous operation of a plurality of indicating devices.

20. A signaling system comprising a plurality of primary controlling circuits in inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices, and means whereby the transmitting devices of any circuit-s in separate groups may operate simultaneously without causing the operation of indicating devices of idle circuits.

21. A signaling system comprising a plurality of primary controlling circuits arranged in inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices and means whereby the transmitting devices of any circuits in separate groups and the transmitting devices of any circuits in the same group may be operated simultaneously without operating the indicating devices of idle circuits.

22. A signalingsystem comprising a plurality of primary controlling circuits arranged in inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices, and means whereby the transmitting devices in any two circuits may be operated simultaneously without causing the operation of indicating devices of idle circuits.

23. A signaling system comprising a plurality of primary controlling circuits arranged in-inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices, and means whereby the transmit-.

ting devices of any plurality of said circuits may be simultaneously operated without operating the indicating devices of idle circuits.

24:. A signaling system comprising a plurality of primary controlling circuits arranged in inter-related groups, a transmitting device for each circuit, signal receiving devices less in number than said circuits, signal indicating devices individual to the circuits, controlled by said receiving devices, and means whereby the operation of any plurality of said transmitting devices will cause the operation of only those indicating devices individual to their circuits.

25. A signaling system comprising aplurality of primary controlling circuits arranged in serially inter-related groups, each circuit including a signal transmitting device, receiving mechanisms. each common to a portion only of said circuits, a signal indicating device for each controlling circuit operated by said mechanisms, and means by the simultaneous operation of the transmitting devices of any two separate circuits will initially operatethat indicating device associated with the circuit first in serial relation, and means for rendering any of said indicating devices inert and means, when the transmitting devices of a plurality of circuits are operated at substantially the same time, for causingthe operation of the :indicating djevice of any such separate circuit when the operated indicating device of a serially preceding circu t has been rendered inert,

271A s gnallng system comprising three .or more primary controlling circuits arranged, in serially inter-related groups, each circuit includinga signal transmitting device, receiving mechanisms each common to a portion only of said circuits, a signal indicating device'ifor each controlling circuit operated by said mechanisms, means for dis sociating any circuit from said mechanism, means whereby the operat on of the transmitting device of a c rcu t 1n any group Wlll cause the operation of its associated'indi eating device and destroy the control of the indicating devices for circuits in subsequently related groups, and means whereby the dissociation or said circuit from said mechanism will restore said control.

28. A signaling system comprising three or more primary controlling circuits arranged in serially inter-related groups, each circuit including a signal transmitting device, receiving mechanisms each common to a portion only of said circuits,a signal indicating device'i'for each controlling circuit operated by said mechanisms, means for dissociating any circuit from said mechanism, means whereby the operation of the transmitting device of a circuit in any group will cause the operation of its associated indicatingdevice and destroy the control of the indicating devices for circuits in subsequently related groups, means whereby the dissociation of said circuit from said mechanism will restore said control, and means whereby the dissociation of said circuit from said mechanism will cause the operation of the indicat ing device of a circuit next in serial relation whose transmitting device has been operated.

29; A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said. circuits, means whereby every two of said relays are jointly controlled as a pair by aseparate primaryeircuit, signal indicators controlled by the operations of the relays, and means whereby the operation of any relay will prevent the operation of any other relay in subsequent relation thereto.

30. A signaling system comprising a plurality or primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays are jointly controlled as a pair by a separate primary circuit, a separate signal indicator controlled by each pair of relays, and means whereby the operation of any relay will prevent the operation of any other relay in' subsequent relation thereto.

31. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays are jointly controlled as a pair by a separate primary circuit, signal indicators controlled by the operations of the relays, and means whereby theoperation of any pair of relays will prevent the opera-. tion of any other pair of relays in subsequent relation thereto.

32. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays are jointly controlled as a pair by a separate primary circuit, signal indicators controlled by the operations of the relays, and means whereby the operation of any relay will interrupt the circuit of any other relay in subsequent relation thereto.

33. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays are jointly controlled as a pair by a separate primary circuit, signal indicators controlled by the operations of the relays, and means for preventing the simultaneous operation of two. pairs of relays.

34. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays are jointly controlled as a pair by a separate primary circuit, signal indicators controlled by the operations of the relays, and means whereby the operation of any pair of relays will interrupt the ci1-. cuit of every otherpair in subsequent relation thereto.

35. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every twoof said relays in separate groups arejointlycontrolled as a pair by a separate primary cireuit, a separate signal indicator controlled by each pairof relays, and means whereby the operation of any relay will prevent the operation of any other relay in subsequentrelation thereto."

36. signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays in separate groups are jointly controlled as a pair by a separate primary circuit, a separate signalindicator controlled by each pair of relays, and means whereby the operation of any relay in a group will prevent the operation of any other relay in subsequent relation thereto in that group.

37. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays in separate groups are jointly controlled as a pair'by a separate primary circuit, a separate signal indicator controlled by each pair of relays, and means whereby the operation of any pair of relays will prevent the operation or" any other pair of relays in subsequent relation thereto.

38. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays in separate groups are ointly controlled as a pan: by a separate primary circuit, a separate signal indicator controlled by each pair of relays, and means for preventing the simultaneous operation of two relays in a group.

39. A signaling system comprising a plu rality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays in separate groups are jointly controlled as a pair by a separate primary circuit, a separate signal indicator controlled by each pair of relays, and means for preventing the simultaneous operation of two pairs of relays.

40. A signaling system comprising a plurality of primary circuits, a source of current supply, a plurality of serially related relays for said circuits, means whereby every two of said relays in separate groups are jointly controlled as a pair by a separate primary circuit, a separate signal indicator controlled by each pair of relays, and means whereby, the operation of any pair of relays will interrupt the circuit of every other pair in subsequent relation thereto.

4L1. A telephone exchange system comprising a plurality of calling lines, an operators position including means for answering said calling lines, signal indicators for the lines, a cut-ofi' relay for each line, means normally controlled by said lines for causing the operation of the indicators, means controlled by one calling line to operate an indicator for that line and to prevent the indicator control of a second calling line, and means controlled by the operator for operating the cut-0E relay for said first mentioned line for eifacing the control of said first-mentioned line whereby an indicator for said second line is operated.

42. A telephone exchange system comprising a plurality of callinglines, an operators position including means for answering said calling lines, signal indicators for the lines, a cut-off relay for each line, means normally controlled by said lines for causing the operation of the indicators,

means controlled by one calling line to operate an indicator for that line and to prevent'the indicator control of a second calling line, and means controlled by the operator for actuating the cut-off relay for the first mentioned line for eiiacing the control of said first-mentioned line whereby the C011. trol of the second line is restored.

43. A telephone exchange system comprising a plurality of simultaneously calling lines, an operators position including means for answering said calling lines, signal indicaters for the lines, an energizing circuit for each indicator, means normally controlled by said lines for closing'the circuits of said indicators upon initiation of a call, and means whereby the circuits of said indicators are closed successively.

44. A telephone exchange system comprising a plurality of calling lines, an operators posit-ion including means for answering said callinglines, signal indicators for the lines,.an energizing circuit for each in dicator,- means normally controlled by said lines for closing the circuits of said indicators upon initiation of a call, and means whereby the circuit of an indicator for but one line is closed until after the operator has answered that line.

45. A telephone exchange system comprising a plurality of calling lines, an operators position including means for answer ing said calling lines, signal indicators for the lines, an energizing circuit for each indicator, means normally controlled by said lines forclosmg the circuits of said indicators upon initiation of a call,means at said position for eilacing said indicators, and

means whereby the closing of the circuit of an indicator for one line is delayed until after the operator has eifaced the indicator for another line.

46. A telephone system including telephone lines, substations having receivers and switchhooks for said lines, call signals therefor at the exchange, a circuit for each of said signals, and electromagnetic switching means normally in circuit with said lines and adapted for operation upon the removal of the receivers at said substations whereby simultaneously initiated calls will be successively indicated by said signals.

47. A telephone system including substa t-ion telephone lines, receivers and switchr h j aw zsi h0 0ks forhs didsubstation s, call signals for 'In witnesswvhereofl'l hereuntofiubscribg "sal'd lmes at the exchange, one only for each my name this 30th day of August 1906. line, an energizing circuit for each signal,

1- 5 T 4 4 h and means operated upon removal of the re- HARRY: DBSTDR m1 "5'. celvgrs at said 'subst-ations t'o close the @nv Wmnesses;

erglzing c1rcu1t of roneiof saldslgnals and A. H. DYSON, prevent .th closing of the other ClICIlltS. I ,CALROLYN VVEBER;

Copies of this patent may be'iobtained fpr five cents each, by addressing the Commissioner of Patents,

V V Washington, D. C.

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