US1216844A - Electrical controlling system. - Google Patents

Description

I; G. ROBERTS.

ELECTRICAL CONTROLLING SYSTEM.

APPLICATION FILED DECIB. I914.

Patnted Feb, 20, 1917.

9Q l s F 32 2 IW 4 I Mm a A33: Q IMW u E I w. NQ

.; UNITED STATES PATENT OFFICE.

OHN G. ROBERTS,- or nouns FERRY, NEW YORK, nssxcNOB, BY Mnsun nssrenmnnrs,

description.

'ro WESTERN ELECTRIC: COMPANY, INCORP ORATED, A CORPORATION OF NEW YORK.

I nnncrrRican ccNTRoLLINc SYSTEM.

. Application filed December a,

To all whom it may concern:

Be it known that I, JOHN G. Ronnnrs,

'a citizen of the United States, residing at Dobbs Perry,

in the county of VVestchester New York, have invented ceruseful Improvements in Elecand State of tain new and trical Controlling Systems, of which the following is a full, clear, concise, and exact This invention relates to electrical controlling systems and is particularly adapted -.for multi-ollice telephone exchange systems.

In such systems it is desirable to prov de connections between subscribers lines which terminate at difl'erent oilices by means of two-wire interoffice trunks, and it is 'desirable also to use the two wires of the trunk k for controllingthe signals and switchesi'n volved in an established connection. It is controlling circuits between the oiiices whi,ch-=--- depend upon a ground return path between the ofiices. In certain systems, such as semiautomatic exchanges providing'" operators- -answering equipment and automatic switches furthermore desirable to avoid the use of under the control of operators senders for completing connections to wanted lines, the wanted subscribers should have control of an operators supervisory signal, and the operator should have control of the release of the automatic switches after the circuit is established. It is also desirable that the. operator have controlof the ringingequip ment, in order to rering on the called subscribers..;line,withoutithe necessity of first restorinfithe connection and building it up again. Because of the long distances between oflice's and high cost of trunk con-- ductors, it isfusual to form the interoffice trunk conductors into a telephonic link and to unite thislink inductively with the line circuits ofi the calling and called subscribers, current to each line being supplied by battery at the oiiice where the line terminates. 1 l

It is'the object'ot' this invention to pro- .vide for the various signaling and switch controlling functions, required in an established interoflice connection in such a system, by means of a single loop controlling circuit extending over the same two wires which constitute the telephonic trunk link. in accordance, the invention provides that the trunk loop be maintained as a closed controlling circuit with a source of current Specification of Letters Patent.

Patented Feb. 20, 1917;. 1914'. Serial in. 876,083.

other common return path at the distant end. A succession of temporary changes in current produced preferably by momentary interruptions at the incoming end eflect the supervisory signalat the'operators end, by

alternately displaying and efiacing it. These current changes are preferably of different kind, such as those caused by a short interruption and one of longer duration, the short ones, being say of one-tenth of a second and the longer ones say of four-tenths of second, and means is provided whereby the called substation switch, in being closed and opened, effects the short and long current changes respectively, in the trunk loop.

The control in the other direction, that is to say, from the operators end of the trunk to the apparatus at the incoming" end, is

effected by similar current changes in the same circuit. Thus the restarting of an automatic ringing apparatus may be effected by a short interruption in the trunk circuit at the operators end, and the release of the automatic switch or switches at the incoming end, whether the called line circuit is,

at the moment open or closed, may be efiected by a prolonged interruptionor opening of the trunk circuit at the operators end.

,This invention iiill be more fully understood by referenc to the accompanyingdrawings wherein is illustrated a system of circuits and apparatus operable in accordanoe with the foregoing general statement. Two subscribers stations, 1,2are, shown In a connection assumed to have been established through a two-wire interofiice trunk link with the circuits and apparatus Involved therein. A. plug and jack switch 3 unites the calling line with an operators connecting circuit, which is divided as is usual into inductive sections by windings 4, 5 and 6, 7 of a repeating coil. The trunk end of this connecting circuit is united with atwo-wire interoiiice trunk line 8, 9 by means of the contacts 10 and 11, say of an automatic switch. The trunk is divided at its incoming end into inductive sections by the windings 12, 13 and 14, 15 of. another repeating coil. A battery 16, at the outgoing end supplies current to the calling line and to the trunk line loop. A. battery 17; at the incoming end supplies current to the called line. A condenser 18, at the outgoing end completes the trunk loop as a telephonic link in the system of circuits between the two stations. Contacts 19, 20, which may also be assumed to be of an automatic switch, unite the called line section of the trunk with the called line.

T he system of circuits is shown in its con dition just following the operation of setting up the automatic switches and preceding the closure at certain contacts in the connecting circuit of the trunk loop between the oliices. are provided for controlling the operation of the circuits associated with the two auto matic switches, indicated in the diagram by the contacts 10-11 and 19-20, respectively. To avoid unnecessary complication in a full disclosure of the invention, much of the apparatus involved in the preceding steps in the operation of the system, that is to say, preceding the setting up of the connections shown in the diagram, is omitted. it is therefore assumed that in response to a call from substation 1, the operator had established a connection at the plug and spring jack switch 3, had inquired of the calling subscriber the number of the party wanted, and had manipulated automatic switch sending apparatus or in some other mannerv had caused the connection. to be set up to the called station 2. The switches used in establishing this connection may be either manual or automatic. and the system as a whole may be manual. full automatic or semi-autonmtic, without departing from the invention broadly, and the number of switches used in making a single connection is immaterial. It is assumcdthat the sequence switch 21 had, by successive stages, reached a resting position 11, and sequence switch a resting position '13. The succeeding resting positions of the sequence switch 21. involved in the operation to be described, are follows: 1'-lringing; 16- talking and 1S--switch-restoring. The succeeding resting positions of the sequence switch are: 16 talking and 1S-switchrestoring. The master switch contacts 105 and 106 are arranged so that the sequence switches 21 and 22, after having been moved out of one resting position, may bekept moving until the next resting position is reached.

Sequence switch 21 is moved out ofposition 11 by the momentary closure of a contact 23, which closure may be effected in any desired manner, prcferal' ly automatically upon the establishment ofthe connection shown in the drawing. In its advance to the ringing position 14, the sequence switch 21 closes at contacts 24 and 25 the trunk Sequence switches 21 and 22 28, 29, 30, 31, 32, s, 10, 24, 6, ground. A I

supervisory relay 26 at the operators end of the trunk, and a trunk relay 33 at the incoming end of the trunk are energized. The former closes a circuit ground, 31, 35, 36, battery. The magnets and 36, with their armatures, constitute an interlocking switch, and when both magnets are energized in the circuit thus traced, the armature 37 of magnet 35 being a little quicker than the armature 38 of magnet 36, prevents the latter from moving forward. A point extension 39 of the armature 37 engages the inside edge of the pointed end 40 of the armature 38. The trunk relay 33 acts to close a circuit for the motor magnet of the sequence switch 22, as follows: ground, 41, 42, 22, battery, and this sequence switch moves out of position 13 into the talking position 16. In passing position 14, sequence switch 22 closes a circuit as follows: ground, 43, 44, -15, battery. A by-path for contact 45 isprovided in this circuit at the contact 46 of the relay 43 when the' latter is energized, so that as the sequence switch 22 reaches position 16, the circuit just traced becomes ground, 43, 44, -16, battery.

The ringing of the called subscribers bell may be effected automatically at this time as follows: A relay 4?, held up by contact 102 in positions 13 and 14 of the sequence switch 22 is released as the sequence switch leaves position 14, closing a ground connection at contact 48 for a local ringing control circuit. Relay 4:? was energized in position 12 of sequence switch 22 over a circuit, from grounded battery, winding of relay 47, upper contact of 102, to ground. The contact 48 remainsclosed during the subsequent operations to be described. hen the se quence switch 22 moves into position 16, this local ringing control circuit is closed through the ringing relay 51 as follows:

ground, 48, 49, 50, 51., 52, 44-, 46, battery. Ringing generator currentis now applied to the called line over a circuit as follows:

generator, 53, 54, 55, 56, 57, 20, 2, 19, 58, 59, ground. Current flows from generator 53 It does operate to the increased current inithe telephone line, and then opens at contact 49 a shunt about the locking relay "'60. The latter in turn closes at contact 61 a-shuntabout the relay Belay 51 therefore reacts, opening the circuit of the ringing generator just traced, and closes the battery circuit to the supervisory 7 follows: ground, 65,

called line.

67 in turn closes two of an impulse relay 6-) as follows: ground,

68, 69,. battery and ground, 70, 71, 72, battery. Relays 71 and 72 are energized, the

' former opening at contact 66 the circuit of subscriber at station 2 therelay 67. The latter is adjusted to release a' brief moment after. it is energized,

say in about one-tenthof a second, so that the impulse relay 69 is given only amomentary impulse of current. I

his momentary impulse of current in relay 69 causes a momentary interruption at contact 28 in the trunk circuit. In order to avoid the release of the trunk relay 33 while the trunk circuit is thus interrupted, a circuit battery, 73, 74, ground, is closed atthe same time, this circuit including a second winding 7% of the trunk relay 33. The energization of. relay 71 closes a locking circuit-battery, 72, 71, 75, 65, ground, which maintains relays 71 and 72 energized while the supervisory controlrelay 62 is energized. The momentary interruption of current in the trunk circuit thus occurring when the answer the call, causes a momentary reaction of the supervisory relay 26 at the operators end of the trunl. This momentarily opens the circuit through magnets 35 and 36, but

1 the magnet 36 is equipped with a copper colc1rcuitground, 38, 76, 77

' lighting of the ringing lamp lar by reason of which it continues to attractits armature 38 after the circuit of its winding is interrupted. But the armature 37 of magnet 35 releases quickly, sothat armature 38 has time in which to move forward while the extension 39 is lifted. The local circuit of the magnets 35 and 36 is however quickly reclosedby the reiinergization of relhy 26, so

that armature 37 of magnet'35 is again attracted. The projection 39 then engages the outside edge of the pointed end 40, of the armature 38.

The sequence switch 21 is at this moment in ringing position 14, and the operation just stated results in the closure of a local 21, battery, which causes the sequence switch to move out of position 1% into talking position 16. 7

While sequence switch 21 was rcstingin position" 14, there had'been closed a circuit,

battery, 78, 79, 80, ground, which causedthe 79. The move- I ment of the sequence switch 21 to position 16 opens this ringing lamp circuit, notifying the opermtor of the called subscribers response, andjcloses a divided (-ircuit,,as follows: battery, 7 8 thence in one path by way of 81, 82, 76, 38 to groundand in another path by way of the supervisory lamp signal closes his line to.

83 and 84 to ground. In this divided circuit, the supervisory lamp signal 83 is brought under control of the contact 76 of the magnet36 and thereby under the control of the supervisory relay 26. At this time it is the contact 76.

shunted by resistance 81 in the path through Subsequent openings and closings of the called subseribers circuit which may be repeated indefinitely at the subscribers switch hook, result in the lighting and eifacing of the supervisory signal 83 in the following manner. Consider first the and the opening at contact 65 of the then existing circuit through relays 71, 72. Relay 71 releases quickly, say. in one-tenth of a second and relay 72 slowly, the latter in about four-tenths of a second, after the current is removed from its winding. This results in an impulse of current of about four tenths of a second in the winding of relay 69, the circuit being as follows: ground, 85, 86, 69, battery. The trunk loop is thus again interrupted at contact 28.

opening of the subscrlberscircuit. This results in the re- .action of the supervisory control relay 62,

This time the interruption is of'longer" duration,'say four-tenths instead of oneup his receiver. A subsequent closing of the called line circuit operates to close contact 76 and effaces the signal 83, the operation being the same as previously described.

In the event that the called subscriber has responded and replaced his receiver, and then the calling subscriber wishes to have the operator recall on the called line, the operator may restart the automaticringing again closed at they 35 again locks the apparatus by momentarily depressing a rering key 87. The operation is as follo'wsi on pushing down the key 87 there is closed a contact 88, and a contact 89, the latterin a, circuit ground, 89, 90, battery, which includes a relay 90. The relay closes contacts 104. and 103 and opens contact 27, estab lishing the following circuits: ground, 103, 2c, 7, 1s; and battery, 88,104, 25,11, 9, 28, 29, 30,31, 32, 8, 1O, 21, ll, ground. WVhen pressure is removed from t e key, contacts 88 and 89 are opened, and relay 90 which is adjusted to release slowly, say in about onetenth of a second, holds contact 27 open for that period and thus lreeps the trunk loop v through the locking relay 6U. Ihe latter slay reacts, opening at contact 61 the shunt alt-out relay 51, and closing at contact 50 the shunt about itself. Relay l3, however, being of the slow release type, maintains its contacts to closed and its contact 91 open. Contact 44 of the trunk relay 33 being quickly reclosed, reestahlishes the circuit through relay 43 so that this relay does not reset. This contact also reestablishes the local ringing control circuit and again energizes the ringing relay 51, which again connects the ringing generator 53 in the circuit of the called line. The subscribers bell is then rung until he responds again or untii the operator proceeds to disconnect in the tuner presently to be stated.

Disconnectionot the lines may be effected under either c in of the circuit of the called line, that ,0 say, Whether the receiver is on or of? the hook at the called station. Under either'condition the trunk loop is closed through the Winding 31 of the trunk relay 33. In a semi-automatic system, such as shown herein, the disconnect operation may be started by the operator removing the plug from the spring jack of the calling line. lhis act breaks a circuit at contact 92 of the plug and spring jack switch 3, in which is ncluded a cord relay 93 and acut-ofi relay 94. Ihe reaction of the cord relay 93 opens battery circuit for the calling supervisory signal 91, and closes at contact 96 a circuit, battery, 21, 95, 96, ground, which cau'ses the sequence switch 21 to move out of the talking position 16 into the swimlrrestoring position 18, wherein there is closed a circuit, battery, 97, 98, ground, which includes'pa restoring magnet 97 for the automatic switch that had previously established the trunk connections at contacts and 11. As the sequence switch 21 moves out of position 16 it opens at contacts 2i and the trunk loop. Trunk relay 33 thereupon reacts, and as the openingin this circuit is prolonged instead of being momentary as in the case of reringing,

relay 43 has time to react and to close a Ail-l,

circuit, ground, 99, 91, 100, battery. This circuit includes the motor magnet of the sequence switch 22 which thereupon moves from its talking position 16 to its restoring position 18 wherein is closed a. circuit, ground, 101, 102 battery, which inclndes'a restoring magnet 110 for the auto matic switch that had previously established ing 31 of trunk relay 33 mo 2. In a telephone exchange system, the I combination with a trunk, and a line circuit inductively united, of a supervisory signal, a switch for opening and closing the hue circuit, means responsive upon both closing and opening the line circuit for producing momentary current changes of like character in the trunk circuit, and means responsive upon successive current changes for alternately displaying and eilacing said supervisory signal.

3. In a telephone exchange system, the

combination with a trunk and a line circuit inductively united, of a supervisory signal, a switch for opening and closing. the line circuit, means for producing momentary current changes of like character in. the

.trunk circuit responsive upon both closing and opening of the line circuit by said switch, and means responsive to the differout current changes for efl'acmg and displaying respectively said supervisory signal.

t. In a telephone exchange system, the combination with a trunk and a line circuit inductively unit-ed, of a supervisory signal, a switch for opening and closing the line circuit, means for producing momentary current changes in the trunk circuit responsive upon both closing and opening of the line circuit, said current changes being of like character but differing in duration, and means responsive to the difierent current changes for efi'acirig and displaying respectively said supervisory signal.

5. In a telephone exchange system, the combination with a trunk and a line circuit inductively united, of a supervisory signal, a switch for opening and closing the line circuit, means for producing momentary current changes of short and of longer duration in the trunk circuit upon the closing and opening respectively of the line circuit, and means responsive to such current changes for controlling said supervisory signal.

6. In a telephone exchange system, the combination with a trunk and a line circuit inductively united, of a supervisory signal at one end of said trunk, an automatic ringing apparatus and a switch controlling magnet at the other end of said trunk, a plurality of current interrupting switches 111 said trunk circuit, means controlled by a succession of, momentary interruptions at one end of said trunkcircuit for controlling said supervisory signal, means controlled by a momentary interruption at the other end of said trunk circuit for controlling said automatic ringing apparatus, and means controlled by a prolonged interruption in said trunk circuit for operating said switch controlling magnet.

7. In a telephone exchange system, a trunk line forming a combined telephonic link and a controlling circuit,-means for producing n'unnentary current changes in said circuit, a signaling device to be controlled over said circuit, and means variably responsive to current changes of varying duration for-alternately displaying and efi'acing said signal. a

8. In a telephone exchange system, the combination with a trunk and .a line circuit inductively united, of a supervisory signal,

a switch for opening and closing a line circuit, n1eans responsive upon both closing and opening the line circuit for producing momentary current changes of varying duration in the trunk circuit, and means variably responsive to such current changes for alternately displaying and'efia'cing said supervisory signal.

9. In a. telephone exchange system, the combination with" a trunk and a line circuit inductively united of a supervisory signal,

means variably responsive to such curre'ntchanges for eifacing and displaying respectively, said supervisory signal.

In witness whereof, I hereunto subscribemy name this 7th day of December, A. D.

JOHN G. ROBERTS. VVitnes'se's:

E. EDLER, F. FEISTER.

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