US1218804A - Selective signaling system. - Google Patents

Description

F. N. REEVES.

SELECTIVE SIGNALING SYSTEM.

APPLICATION FILED FEB. 21. 1915.

Patented Mar. 13, 1917.

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F. N. REEVES. SELECTIVESIGNAL ING SYSTEM.

. APPLICATION FILED FEB. 27. 1915.

1,218,804. Patented Mar. 13, 1917.

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Wi/rresses: /m/e/1f0r.-' @3441. 8 flank N. Reeves i the signaling current selecting FRANK N. REEVES, OF NEWARK, NEW E RSEY, -ASSIGNOR, BY MESNE ASSIGNMENTS,

TO WESTERN-ELEGTRIC COMPANY, INCORPORATED, A CORPORATION OF NEW YORK.

SELECTIVE SIGNALING SYSTEM.

Specification of Letters Patent.

Patented Mar. 13,1917.

Application filed rebi-uary'azjiela Serial N5. 11 ,o43.

To all whom it may concern;- V

Be it known that I, FRANK N. REEVES, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Selective Signaling Systems, of which the following is a :tull, clear, concise, and exact description.

This invention relates to party line selective signaling in telephone exchange systems.

It is particularly useful in systems employing a plurality ofswitches adapted in serial combinations to efiect the desired exchange connections. Its object is to provide, by simple mechanism economically situated, an effective system of control for selective signaling, and one in which a wide choice of numbers is available 'for the several sta tions on the party lines.

In applying the invention, recourse may be had to any one 01" a number of well known methods of selective signaling, for example: (1) the application to the party line of ringing currents of different characteristics, such as positive and negative pulsating currents and such as alternating currents of difierent frequencies; (2) the application of ringing current to each of a plurality of line wires, such as the two line wires of a metallic telephone circuit, and (3) various combinations of (1) and (2).

Economy of equipment may be secured in accordance with the invention of combining and applying mechanism, in part at least, with the trunking switches, preferably those immediately preceding the final switches, rather than with the final switches, as has generally been the practice heretofore. This is of advantage where fewer trimking switches than final switches are required. It is also advantageous in the system of the invention that the switches themselves in their operation determine and control the adjustment of the selective signaling mechanism. Furthermore, by utilizing trunking switches to perform the additional function of signaling current selectors, it is possible to vary within very wide limits the numbers assigned to the different stations on a party line. For example, in a ten thousand line automatic or semi-automatic exchange system. trunk selectors may be provided with fixed terminals representing twenty groups of twentyfive trunks each, each trunk leading to a final selector, and each group of final selectors having access to a group of five hundred sets of terminals representing five hundred subscribers stations, some, (or all) of which may be party line stations. In such a system it may then be provided, in accordance with the invention, that when any of ten of the twenty trunk groups is selected by a trunk selector, positive pulsating signaling current is applied at the trunk selector to an idle trunk of the selected group and by way of a final selector to the party line; whereas, when any of the other ten groups of trunks is selected, negative pulsating signaling current is similarly applied. Such a system would be suitable say for two-party lines, and in it the number of one of the stations on any party line may be any of five thousand of the ten thousand possible exchange numbers, while the number of the other station on that line may be any of the remaining five thousand numbers.

For party lines having a considerable number of stations, say four, the invention furthermore provides selective signaling means consisting in part of characteristic current selecting means and characteristic line wire selecting means controlled respectively by selectors in series. Preferably one or the other of two characteristic signaling current sources is selected in the operation of a trunk selector, in accordance with the trunk groups selected, and one or the other of the subscribers line wires over which the signaling current is to be conducted is selected in the operation of the final selectors in accordance with the line terminals selected. In this manner stations, designated say A and C, are signaled by positive pulsating current applied at the trunk selectors and conducted by the final selectors either to one or other of the two line wires, according to whether the A or the G station is to be signaled. In a like manner the other two stations, designated say Band D, are signaled by negative pulsating current applied at the trunk selectors'and' conducted by the final selectors to one side or the other 'of the party lines according to whether the B or the D station is to be signaled.

The invention will be more fully understood by reference to the accompanying drawings wherein,

Figures 1, 2 and 3 together are illustrative of a system or circuits of a semi-automatic telephone exchange system embodying the invention, Fig. 1 including a calling telephone line and part of an operators connecting circuit equipment, Fig. 2 including circuits of a trunk selector, and Fig. 3 cir cuits of a final selector and a party telephone line.

The following description of the system illustrated in these drawings is written under the assumption that any form of selector mechanism and apparatus for the control thereof may be employed. Such equipment is not in itself a feature of the invention and most of the details thereof are omitted to simplify the disclosure and because many forms therefor are well known. The invention has been found useful in connection with automatic switches of the panel type, as disclosed for example in patent to Reynolds, No. 1,058,903.

In the drawings there is shown a calling line 1 leading to a station S, and a party line 2 comprising the two line wires 3 and a leading to stations A, B, C and D, any one of which may be called for by a subscriber at the calling station. Connection between these lines may be had by any suitable switching apparatus. As shown, there is provided an operators connecting circuit terminating at one end in an answering plug 5 vhich may be inserted in the answering jack 6 and at the other end in an automatic switch 7 which may conveniently be called a district selector. By means of any suitable sender mechanism indicated at 8, the operator may adjust the district switch 7 to extend the connecting circuit to a trunk line including the two talking circuit wires 9 and 11 and local wire 12. At the incoming end of this trunk is apparatus associated with another automatic switch 13, which may conveniently be called an incoming trunk selector, or merely trunk selector. It may be provided that this trunk selector 13 is also adjustable under the control of the sender 8, and when thus adjusted, it extends the circuit on by way of another trunk line comprising the talking circuit wires 1% and 15 and local wire 16 to the apparatus as sociated with another automatic switch 17 which may conveniently be called a final selector. This final selector 17 when adjusted, say also under the control of the sender 8, extends the connection to some called line, such as the party line 2.

Certain of the structural features" of the trunk selector 13 are illustrated diagram matica-llv in order to show the manner in which this selector also controls the selection and application of ringing current for party line signaling. The fixed portion of the selector may comprise, as indicated, a plurality of groups (four groups only being shown), of sets of trunk terminals arranged 'vention, that different sets in three rows, and a commutator plate 19. The several groups of terminals are indicated by brackets 21., 22, 23 and 2a and the commutator plate is divided into four quarter sections, 25, 26, 27 and 28, of which 26 and 27 are conducting and and 27 nonconducting. At the lower end of the plate is a conducting terminal 29. The movable portion of the selector may comprise a set of three brushes 31, 32 and 33, each adapted to sweep over a row of fixed terminals, and a pair of commutator brushes 3% and 35, the former being adapted in the movement of the selector to sweep over the commutator sections 25, 26, 27 and 28, while the brushes 31, 32 and 33 are in contact with terminals in the groups 21, 22, 23 and 2 1, respectively, and the latter normally rests upon the contact 29. hen the brushes are lifted and in contact with any of the terminals, the connection between the brush 35 and contact 29 is broken.

As will appear more fully hereinafter, the position of the commutator brush 3%, when the trunk selector 13 has been adjusted for a given connection, determines whether positive pulsating or negative pulsating ringing current from the generators 37 and 38 is to be applied to the selected trunk. That is to say, if, when the selector is adjusted, the brush 341 rests on a non-conducting segment 25 or 27, corresponding to the trunk groups 21 or 23 respectively, generator 37 will be connected in circuit; whereas if the brush rests upon the conducting segments or 28, corresponding to the trunk groups 22 0r 2d respectively, generator 38 will be connected in circuit.

The selection of line wires over which the current is to be conducted, is determined by the connections of the party line to the fixed terminals of the final selector-s. As indicated in Fig. 3, the two talking circuit wires 3 and a of the party line 2 are connected in the same order to terminals all and 42 of selector 17 and terminals 44: and d5 of a selector, 20 of another group, but in reverse order to terminals d7, 4:8 and 51, 52. The line may have, as ordinarily, a local circuit wire 39 leading to a cutoff relay 10 and extending to local circuit or test terminals as, 16, 49 and 53. The terminals 47, 4L8 and 49 may be as indicated, on the same selector 17 as the terminals 11, 42 and 13, or they may be on a different selector. In a similar manner,

the terminals 4A, and a6 may be On the same or a different selector with the terminals, 51, 52 and 53; but it is required, according to the preferred system of the inof terminals of any line connected in like .order shall be located on different groups of final selectors.

From the foregoing it will be seen that the trunk selector 13 has a choice of groups of trunks leading to final selectors; that if certain groups are selected, positive pulsating current is selected and applied by the trunk selector to the trunk leading to some final selector, whereas if other groups are selected, negative pulsating current is likewise selected and applied. The connection having been extended to the final selector, such as 17, the adjusted position of its brushes, say to terminals 41, 42 and 43, determines that the signaling current, negative pulsating in this case, shall be applied over lino wire 4, thus signaling the bell at station B. If, however, the final selector 17 is adjusted to make connection at the terminals 47, 48 and 49, the signaling current negative in this case also, will be extended over line wire 3 and will ring the bell at station D. If the trunk selector 13 has access to twenty groups of twenty-five trunks each and each group of final selectors has access to 500 sets of line terminals, the total capacity of the exchange in stations is 10,000. The numbers in such an exchange that may be assigned to stations A and C may be any of the numbers from 0 to 4999, and the numbers for the stations B and D may be any of the numbers from 5000 to 9999.

The circuits associated with the trunk selector 13 in Fig. 2 are controllable in part by a sequence switch 54 which may have a number of resting positions as follows: 1 normal, 2 to 12 inclusiveselector control, 13awaiting trunk closure, 16talking, 17overflow, 18switch restoring. A sequence switch 55 is also provided for the control in part of the circuits of the final selector 17, Fig. 3. This sequence switch has resting positions as follows: 1normal, 2 to 6 inclusive-selector control, 7awaiting trunk closure, c -testing line, 16talking. The circuits associated with the district switch 7 and operators connecting circuit may also be controlled by a sequence switch, but only a few of the switch contacts are shown to make clear a few of the controlling operations of the trunk selector and final selector.

The operation more in detail is as follows: Assuming that a subscriber at station S is calling for a subscriber at any one of the four stations A, B, C and D of the party line 2, the operator first answers the call by inserting the plug 5 into the spring-jack 6, then sets up on the sender 8 the number representing the station wanted. Having set up the number, whatever it may be, on the sender 8, the trunk selector 7 is first adjusted to extend the connection to the proper district or ofiice in which the called line terminates, whereupon the senderis brought into circuit over thetalking circuit wires 9 to 11 of the trunk by way of sequence switch contacts 56 and 57. Contact 58 of the sender being closed to start the selecting control operation for the trunk selector 13, there is completed a circuit which energizes the line relay 59 as follows:

(1) Battery, 59, 61, 62, 9, 160, 150, 56, 58, 63, 57, 149, 151, 11, 64, ground. Line relay 59 acts to close at its contact a locking circuit by way of sequence switch contact 66, so that the relay remains energized when its original path through sequence switch contact 61 opens. By reason of the closing of relay contact 67 which completes a circuit directive movements of the trunk selector 13, 1

and at the end of that movement the line relay 59 is deenergized by the opening of circuit (1) at contact 58 of the sender, whereupon line relay 59 reacts closing a circuit for sending the sequence switch 54 out of position 2 into position 3 as follows:

(5) Battery, 54, 72, 82, 84, 71, ground. The sequence switch 54 is then advanced from position 3 to position 4 in the same manner that it was advanced from normal to position 2, that is to say, by the reclosing of the trunk circuit at contact 58 of the sender. These operations are repeated a number of times during the control of the trunk selector 13, and by the time the sequence switch 54 reaches position 8, the selector 13 has formed a connection with a trunk line leading to a final switch, such as the trunk line comprising the wires 14, 15 and 16 leading to the final switch 17. The line relay 59 being energized at this time, there is closed a circuit extending to the line relay of the final selector as follows:

(6) Battery, 85, 88,89, 14, 91, 33, 92, 67, 71, ground.

Then this circuit is closed, the final sequence switch 55 advances to position 2 by the clos ing of a circuit.

(7) Battery, 55, 94, 95, 96, ground. The final trunk relay 97 is at the same time energized by the closing of a circuit.

(8) Battery, 97, 98, 95, 96, ground, and like the trunk relay 68, it closes a locking circuit for itself by way of the local wire 16 as follows:

(9) Battery, 97, 99, 101, 16, 102, 31, 104,105, ground.

The sequence switches 54 and are now in positions 8 and 2 respectively. Further operations of the sender causing successive openings and closings of the contact 58, carry the sequence switches on so that the sequence switch 5-1 moves from 8 to 13 while sequence switch 55 moves from 2 to 7. This period is provided for the directive operations of the final selector 17, whereupon the brushes of the final selector are brought into connection with terminals 11, 4:2 and 13 of the party line Further movement of the trunk selector sequence switch 54: occurs upon the closing of the trunk circuit at contacts 106 and 107 of the district sequence switch, the sender being then disconnected by the opening of sequence switch contacts 56 and 57. Q1 circuit is then closed for energizing the line relay as follows:

(10) Battery, 59, 01, ca, 9, 160, 150, 107, 10s,

ground.

Linc relay 59 again closes a circuit (11) Battery, 5 1, 109, 67, 71, ground, which sends the sequence switch 51 on to position 16.

in this position of the sequence switch either one of the pulsating generators 37 and 38 will be brought into a signaling cir cuit extending to the called line, depending on whether the commutator brush 3 is at that time resting on a non-conducting segment 25 or 27 of the commutator plate 19,

or on a conducting segment 26 or 28 thereof.

1f the trunk selector had stopped with the brush 3-1 resting on the non-conducting segn'ient or 27 of the commutator 19, which would be the condition if a trunk of group 21 or group 23 had been selected, the positive pulsating generator 37 will be brought into the signaling circuit extending by way of the trunk line 15 to the called line. If, however, the trunk selector had been oper ated to select a trunk in group 22 or group 21, the brush 3% would be resting on a conducting segment 26 or 28 and there would have been closed, while the sequence switch passes through the fifth position, an energizing circuit for relay 111 as follows:

Battery, 111, 111, 112, 28, or 26,

ground, also a locking circuit as follows:

(13) Battery, 11 1, 111, 115, ground. Relay 111 will in such case by operating contact 113 break the connection for the positive pulsating generator 37 and bring the negative generator 38 into the signaling circuit extending by way of trunk line 15 to the calling line.

The operation of the trunk selector sequence switch 51 in its advance from position 13 to 16 having been described, it should be stated that in the meantime the final sequence switch 55 had been caused to advance from position 7 to the talking position 16, provided the line tested by it had been found idle. The circuit for causing the final sequence switch 55 to move out of position 7 included the line relay 85 and was as follows:

(11-) Battery, 85, 88, 89, 141, 91, 33, 93, 94, 62, 9, 160, 150, 107, 108, ground. The line relay 85 thereupon closed circuit (7) sending the sequence switch 55 out of position 7 into 8, wherein the test relay 116 y is brought into a testing path leading from ground to the test terminal 43 (or 19) of the called line as follows:

(1.5) Ground, 117, 118, 120, 121, 122, 13. If the called line is idle, the presence of full battery potential on the test terminal 13 through the cutoff relay 10 and local wire 39 causes the energization of the test relay 116, whereupon its higher resistance winding 117 is short circuited at the relay contact 123, the complete local wire circuit then being as follows:

(16) Ground, 123, 120, 121, 122, 4:3, 39, 10,

battery. The cutoff relay operates as usual and the test relay 116 remains energized. This relay also closes at the moment of testing the line (if idle) a circuit for advancing the sequence switch 55 out of testing position 8 and on to the talking position 16, the circuit being as follows:

(17) Battery, 55, 124, 125, ground.

The trunk selector sequence switch 51 is now in talking position 16, and the final sequence switch 55 in talking position 16. The former, when it had reached position 16, had closed a circuit for energizing the ringing relay 126 as follows:

(18) Ground, 126, 127, 128, 129, 82, 841, 131,

battery.

This ringing relay 126 now closes the signaling circuit which, assuming the brush 3 1 resting on a non-conducting segment 25 or 27 is as follows:

4:2, 41, 139, ground,

ringingv the bell 139 at the station A of the party line 2. At the same time, the ringing relay 126' places ground at contact 111 on' the other side of the talking circuit leading to the called line, so as to short circuit and prevent the sounding of the ringers at the station-C. If the brush 34: had rested on a conducting segment 26 or 28, the signaling circuit would have been the same as previously traced, except that it would have included the negative pulsatinggenerator 38, the winding 142 of the trip relay 1 10 and the sequence switch contact 143, and the bell at station B would have been sounded. In

either case, there is included in this circuit 7 relay 140 opens at its contact 128 a short circuit which had previously existed in circuit (18) about the locking relay 144, whereupon the latter relay is energized opening at 127 another contact in the short circuit referred to and closing at contact 145 a short circuit about the relay 126. Ringing relay 126 is now denergized restoring the talking circuit at contacts 146 and 93, whereupon the circuit of the called line is completed as follows:

(20) Battery, 147, 14s, 106, 149, 151,11, 152, 14c, 32, 135, 15, 136, 13s, 42, 4, B, 3, 41, 15 3, 154, 89, 14, 91, as, 93, 94, e2, 9, 160, 150, 107, 108, ground.

When the subscribers are through talking and signal to disconnect by means of supervisory apparatus 148, 155, the operator may, in any suitable manner, bring about the restoration of the various switches used in setting up the connection. I In the diagram there is shown for the purpose the contact 81 of the district sequence switch which becomes opened as the sequence switch is moved out of talking position 16. That movement results in the opening of circuit (4) including the trunk holding relay 68. This relay reacts, closing at contact 156 a circuit for sending the sequence switch 54 out of talking position 16 into switch restoring position 18, the circuit being as follows (21) Battery, 54, 157, 156, ground.

On reaching its normal position, the commutator brush 35 closes at contact 29 a circuit for sending the sequence switch 54 out of position 18 to normal.

When the trunk sequence switch 54 left position 16, circuit (9) for the trunk holding relay 97 was opened, allowing this relay to react, and closing a circuit for sending the sequence switch 55 out of talking position 16 into the switch restoring position 18, this circuit being as follows:

(22) Battery, 55, 158,159, ground. WVhen it returns to normal, the sequence switch 55 may be advanced from the switch restoring position to normal position 1 in the same manner (not shown on Fig. 3) as had been the trunk selector sequence switch 54.

From the foregoing description, particularly the tracing of the ringing circuit (19) for signaling station A of the party line, it will readily be seen that similar circuits would be set up for signaling stations B, C and D. Station B, for example, would be called over a circuit such as traced for signaling station A, except that the negative pulsating current generator 38 would be in circuit instead of the positive pulsating generator 37. To signal station 0, generator 37 would be brought into circuit by way of trunk conductor 15, but over line wire 3 instead of 4 by reason of the reverse connections of the line to the terminals 48 and 49 which are provided for that station. The signal station D, the generator 38 would be brought into circuit, and in this case the ringing current would flow by way of some trunk conductor 15 and line wire 3.

What is claimed is:

1. I11 a telephone exchange system, the combination with party lines, final selectors, a trunk selector and trunk lines leadmg from said trimk selector to said final selectors, of signaling mechanism for applying selective signaling current by way of said trunk selector, and means operative in response to the selection of a certain trunk for connecting said mechanism to the selected trunk.

2. In a telephone exchange system, the combination with party lines, final selectors, a trunk selector and trunk lines arranged in groups, leading from said trunk selector to said final selectors, of selective signaling current mechanism for applying selective signaling current by way of said trunk selector, and means operative in response to the selection of a certain group of trunks to apply'the signaling current to selected trunks.

3. In a telephone exchange system, the combination with party lines, trunk selectors, trunks and final selectors, of mechanism for applying selective signaling current by way of said trunk selectors through said trunks and final selectors to said lines including controlling means for said mech anism actuated in response to the selection of a certain trunk.

4. In a telephone exchange system, the combination with party lines, trunk selectors, trunks and final selectors, said trunks being arranged in groups, of mechanism at said trunk selectors for applying selective signaling current by way of said trunk selectors through said trunks and final selectors to said lines including controlling means for said mechanism actuated in accordance with selected trunk groups.

5-. In a telephone exchange system, the combination with party lines, trimks, and a plurality of selectors adapted in serial combinations to extend connections through said trunks to said lines, of selective signaling means at said selectors consisting in part of characteristic current selecting means operated in response to the selection of a certain trunk and characteristic line connection selecting means controlled by selectors in series.

6. In a telephone exchange system, the combination with party lines, trunks, trunk selectors and final selectors, of selective signaling means at said trunk selectors consisting in part of characteristic current selecting means operative in response to the selecof characteristic line connection selectingmeans controlled by the final selectors.

8. In a telephone exchange system, telephone lines, means including a selector switch and connector switches for completing a connection to a called line, trunks extending from said selector switch to said connector switches, sources of ringing current of different characteristics at said selector switch, and a current selecting device at said selector and controlled by the position thereof if certain trunks have been selected, for selectively applying ringing current to called lines.

9. In a telephone exchange system, telephone lines, means including a selector switch and connector switches for completing connection to called lines, trunks extending from said selector switch to said connector switches, sources of ringing current of different characteristics at said selector switch, and a circuit controlling device at said selector and controlled by the position 'of said selector switch while seizing a desired trunk for selectingand applying ringing current to a selected trunk upon a connection being completed to said line.

10. In a telephone exchange system, telephone lines, means including a selector switch and connector switches for completing connections to called lines, trunks extending from said selector switch to said connector switches, sources of ringing cur rent of different characteristics at said selector switch, a current selecting device at said selector switch operative in response to the selection of a certain trunk for connect ing said mechanism to the selected trunk.

11. In a telephone exchange system, telephone lines, means including a selector switch and connector switches for completing connections to called lines, groups of trunks extending from said selector switch to said connector switches, sources of ringing current of different characteristics at said selector switch, a current selecting de= vice at said selector switch and passive con tacts associated with the terminals of the trunks of certain groups at said selector for controlling the operation of said current selecting device.

"12. In a telephone exchange system, the combination with a plurality of lines, final selectors, a trunk selector, trunk lines leading therefrom to said final selectors, of signaling mechanism for applying selective signaling current by way of said trunk selector, and means operative in response to the selection of a certain trunk for connecting said mechanism to the selected trunk.

13. In a telephone exchange system, the combination with a plurality of lines, final selectors, a trunk selector, trunk lines lead ing therefrom to said final selectors, of se lective signaling mechanism, and a relay at said trunk selector operative in accordance with the selection of a certain trunk for connecting said mechanism to the selected trunk.

14-. In a telephone exchange system, the combination with a plurality of lines, final selectors, a trunk selector, trunk lines leading therefrom to said final selectors, of selective signaling mechanism including sources of current of different characteristics, a circuit at said selector includin a relay for controlling the application 0 currents of different characteristics to selected trunks, and means for controlling said circuit actuated by said trunk selector while seizing a desired trunk.

15. In a telephone system, a plurality of telephone lines, means including a selector switch for completing a connection to a called line, groups of trunk terminals at said switch, conducting segments at said switch, each being co-extensive with the ten minals of some one of said groups, a ringing current selecting relay at said selector switch, and a circuit for said relay having branches including said conducting segments.

16. In a telephone exchange system, a plurality of telephone lines, a selector switch operating through long and short movements to complete a connection to a called line, sources of ringing current of different characteristics, conducting segments at said selector switch coextensive with the long movements of said switch, a relay for selecting one or another of said sources of current, and circuits for said relay controlled through said conducting segments.

17 In a telephone exchange system, telephone lines, switches movable in a single direction through long and short steps, sources of ringing current of different characteristics, conducting segments at said switch, each being co-extensive with a long movement of the switch, a relay for selecting one or another of said sources of current, and a circuit for said relay controlled through one or another of said segments.

18. In a telephone exchange system, a plurality of telephone lines, a selector switch, groups of trunk terminals at said switch, means for moving said switch in a single direction over said groups of terminals, and subsequently for moving said switch from terminal to terminal of a group, conducting segments at said switch, each being co-extensive with one or another of said groups of terminals, sources of ringing current of different characteristics, aringing current selecting relay, and a circuit for said relay, arranged to be completed through one or another of said conducting segments.

19. In a telephone exchange system, the combination with party lines, a trunk selector, trunks and final selectors, of mechanism for applying selective signaling current by Way of said trunk selector through said trunks and final selectors to said lines including controlling means for said mechanism actuated by said trunk selector.

In Witness whereof, I hereunto subscribe my name this 26th day of February, A. D.,

FRANK N. REEVES. Witnesses:

E. EDLER, K. L. STAHL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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