US1381195A

US1381195A - Telephone system

Info

Publication number: US1381195A
Application number: US297244A
Authority: US
Inventors: Harry H Ide
Original assignee: Kellogg Switchboard and Supply Co
Current assignee: Kellogg Switchboard and Supply Co
Priority date: 1919-05-15
Filing date: 1919-05-15
Publication date: 1921-06-14
Anticipated expiration: 1938-06-14

Description

HQH. 10E.

TELEPHONE SYSTEM.

APPLlCATluN man MAYI5,1919.

1,881,195, n PGlled June 14,1921;

2 SHEETS-s115171.

H. H. IDE.

TELEPHONE SYSTEM.

APPLxcATmN FILED MAY151919.

Patanted June M9 @EL lamg,

UNITED STATES PATENT OFFICE.

HARRY H. IDE, OF LA GRANGE, ILLINOIS, ASSIGNOR TO KELLOGG SWITCI-IBOARD AND SUPPLY COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION 0F ILLINOIS.

TELEPHONE SYSTEM.

Application led May 15,

T 0 al? vwhom it may concern Be it known that I, HARRY H. IDE, a citizen ot' the United States of America, residing at La (lri'ange, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Telephone Systems, of which the following is a speciication.

My invention relates to telephone systems and has to do more particularly with systems of the type in which impulses transmitted from a calling substation actuate switches to seek the contacts of the line being called. The system which is herein disclosed is particularly applicable to private branch exchange systems and is commonly known in the art as a private automatic exchange, although my invention is in no sense limited to such use. The system'is adapted to serve a plurality of stations, say twentyive in number, each station of the system being supplied with a single motion rotary switch.

A system of the type above described does away with the usual operator used-in manual private branchlsystems, and an object of my invention is the provision of an improved circuit arrangement which embodies desirable features and advantages all in an efiicient, simple and economical manner.

| s The novel features of the invention through the provision of which the above' mentioned and other advantageous results are attained will be explained by reference to the accompanyingdrawings, in which like reference characters in the severalviews denote like parts and in which- Figure 1 is a plan view of a switch adapted to operate in connectionwith the circuit arrangement;

Fig. 2 is a front elevation of the switch;

Fig. 3 is a right side elevation of the switch;

Fig. 4 is a sectional view of the main shaft showing its constructions, and

Fig. 5 illustrates diagrammatically a system including the circuit of my invention.

Referring now more particularly to the switch structure illustrated in Figs. 1 to 4, inclusive, the switch comprises a mounting plate 2 to which are secured the operating parts of the switch and also the bank of con- Speccation of Letters Patent.

Patented June 14., 1921. 1919. serial No. 297,244.

tacts B. The switch as illustrated in Figs. L to 4 is similar to the type of switch illustrated and described in my application, Serial No. 271,960, filed January 20, 1919.

The bank contact-s B coperate with the wipers lV, which latter are supported upon a shaft S. Plate 2 further supports a motor magnet MM, a combined line and interrupter relay LR, a switching relay SW and a ringing relay RI.

Contact bank B comprises any suitable number of contact sets, each set including a private contact 4, a common Contact 5 and line contacts 6 and 7. Twenty-live sets of contacts 4, 5, 6 and 7 per switch is a convenient number. The contacts are radially disposed between the clamping plates 8 and 9 and are properly spaced and insulated from each other. Bolts 10 and nuts 11 form the clamping means to secure the contact bank B, as a whole, between the plates 8 and 9.

To secure the bank of contacts t'o the supporting posts 3 (which are securely fastened tio the plate 2), I provide the lower lateI 9 with

ears

12 and 13 bent over parallelpto the plane of the said plate.

Ears

12 and 13 and plates 8 and 9 have openings to receive posts 3. The bank B, as a whole, is slipped over the posts threaded engagement with the bridge portion of the

ears

12 and 13 are tightened to maintain the bank B, as a. whole, in its adjusted position.

' lVipers 15, 16, 17 and 18, which coperate with the contacts 4, 5, 6 and 7 comprise two oppositely extending arms each and the bank Contact B, as a whole, forms a semi-circle so that when one set of wiper arms leaves the last contact set, the other set of wiper arms engages the-first contact set. The wipers 15, 16, 17 and 18 are carried by a hub 19, which is slipped over the shaft S and when the wipers are adjusted in relation withl the contact banks, a set screw 20 is tightened to hold the wiper unit 7V upon the shaft S. The wipers l5. 16, 17 and 1S are conductively connected to conducting, rings 21, 22,

23 and 24.` respectively, which a'ire also suitably mounted upon the hub 19 but insulated 3, and screws 14 which have screwsurfaces for

wiper brushes

25, 26, 27 and 28, insulatingly mounted upon a stud 29 and clamped yby means of the nut 30, the stud 29, as a whole, being then secured to the plate 2 by means of the screw 31. The

brush wipers

25, 26, 27 and 28 contact respectively' and permanently with the conducting rings 21, 22, 23 and 24, and since the rings are as stated conductively connected to wipers 15, 16, 17 and 18, wipers 15, 16, 17 and 18 are always conductively connected to

terminals

26, 27 and 28.

Sleeve 32 supported by plate 2 serves as a bearing forthe shaft S and also as a bearing for the ratchet 33l which operates to rotate the shaftv S and the wiper unit 1V over the bank contacts. The sleeve 32 has its one end 32 threaded and its other end provided with a flanged portion 322,- the said ianged portion 322 resting in a recess 34 in the ratchet 33. A collar 35 hasscrew-threaded engagement ,with the threaded portion 32 of the sleeve 32 and its peripheral surface also forming a bearing for the ratchet 33. The collar 35 is provided with a reduced portion 36 which fits into a suitable orifice 37 inthe plate 2.- I provide a nut 38 which has screw-threaded engagement with the threaded portion 32of the sleeve 32 and when the proper adjustment of the ratchet 33 and parts is obtained, the nut 38 is tightened to secure the sleeve 32 and its supported parts in their Vadjusted position. A plate 39 is secured to the ratchet 33 by means of: the

screws

40 and 41, and is provided with anI angular extension 42 for purposes as' will presently be described. The shaft S is provided with a squared portion 43 at its upper end which enters a square opening 44 in the plate 39. A suitable screw 45 passing through a suitable opening in the plate 39 has screw-threaded engagement with, a suitable tapped orifice in the' squared end 43 of hthe shaft S, thus connecting the shaft S to the plate 39 so that when the ratchet 33 is rotated, as will presently be described, the shaft S is also rotated therewith.

The motor magnet MM, which is adapted to move the wipers over bank contacts, includes a pole piece 46, an armature 47, and a driving paWl 48. The eleetromagnet 49 is suitably secured to the pole piece 46 by means of a screw 50 which passes through a stud 51, the said screw having screw-threaded engagement with ay suitable tapped opening in the core 52 of the magnet 49.

The pole piece 46 has projecting ears 53 bent at right angles to the main part of the said pole piece, the said ears having suitable tapped orifices which receive screws 54 to fasten the magnet l49, pole piece 46 and armature 47 as a unit to the mounting plate 2. 4The pole piece 46 is provided with projecting ears 55, bent at right angles to the main part of the pole piece, the said ears having suitable openings to receive the pivot pin 56, which plvot pin 56 pivotally suports-the armature 47 of the motor magnet M. The armature 47 is also provided with ears 57 which have suitable openings to receive the said pivot pin 56. A U-shaped member 58 is also provided, the arms ot' which also have suitable openings for receiving the pivot pin 56. T o pivotally support the armature 47 upon the pole piece 46, the pivot pin 56 is inserted through the openings in the ears of the pole piece 46 and the ears 57 of the armature 47, and through the openings in the arms of the U-shaped member 58. One arm of the member 58 fits between one of the supporting ears 55 of the pole piece 46 and the adjacent ears 57 of the armature 47. A set screw 60 is provided and has screw-threaded engagement with the yoke end of the U-shaped member 58. The set screw 60 is used to securely hold the pivot pin 56 in place relative to theheel iron 46 and armature 47.

rllhe armature 47 carries a pivoted driving pawl 48 which is normally held against an adjustable stop 62 by means ot a leaf spring 63, the said leaf spring 63 being held in place by means of a screw 64. T he adjustlable stop 62' is pivotally secured to the mounting plate 2 by means of a screw 65. The sto 62 has an enlarged end 62 provided wlth a slot 66, through which a screw 67 passes. To adjust the pawl 48, the screws and 67 areloosened and thestop 62 is then moved about its pivot screw 65, causing the angular portion 622 to move to the right or left, as the case may be, and when the proper adjustment is obtained, the screws 65 and 67 which have screw-threaded engagement with suitable tapped openings in the plate 2, are tightened to hold it in its adjusted position. The armature 47 is held in its normal position by means of a coil spring 68, thetsaid spring having its one end fastened to a pin 69 which is staked to the pole piece 46, and its other end 'is secured to an adjustable screw 70. The screw 70 passes through a suitable openingin the arm 71, which arm 71 is integrally formed with the armature 47, thel said screw 70 being provided with an adjustable nut 72. The tension of the `spring 68 is regulated by means of the nut 72. A set of contact sprin J is associated with the motor magnet. M, the said springs being insulatingly mounted upon the pole piece 46 by meansof the screws 73, which are suitably insulated from the springs J.

The pawl 48 is adapted to engage a tooth of the ratchet Wheel 33 u on each actuation of the motor magnet. Ml and an adjustable stop post 74 is provided to limit the stroke of the pawl 48 so that the wipers 15.

16, 17 and 18 are only advanced one step at a time. The stop post 74 has a reduced pormames tion which passes through a suitable slot in the plate 2. The stop 74 may be moved forward or backward as the case may be, and when the desired adjustment is obtained suitable means are tightened to securely hold the stop 74 in its adjusted position.

The line relay LR, ringing relay RI and the switching relay SW are suitably mounted upon a bracket 76, which bracket .is in turn secured to the mounting plate 2 by mean-s of the screws '77. The relays LR, RI and SvV are similarly constructed and comprise the usual electromagnet 78, heel iron 79 and pivoted armature 180. Nuts 181, having screw-threaded engagement with threaded portionsof the core of the electromagnets, secure them to the bracket 76.

A set of oil-normal contacts ON are insulatingly mounted upon a bracket 182 by means of the screws 183, and are held in their normal position by means of the angular extension arm 42 of the plate 39 in the form ot' an arm 42. The arm i2 when the switch is at normal engages a rubber butter 283 to hold the said oit-normal contacts ON in their normal position. Upon the first step of the switch Wipers oli normal, the arm 42 disengages the butter 283 allowing the contacts ON to assume their alternate position and remain in such position until the arm 42 again engages the buti'er 283` which occurs when the switch has completed a revolution. The bracket 182 is suitably secured to the mounting plate 2 by means of the screws 184. A condenser K is mounted upon the plate 2 by means of a bracket 185 secured to the plate 2 by means of the screw 186.

The circuit in Fig. 5 shows a calling substation A connected to the switch circuit D of my invention and adapted t0 operate with the switch structure just described. The calling substation A comprises the usual substation apparatus and in addition comprises a calling device CD and a grounding or ringing key GK for purposes as will presently be described, and the called line C is similarly equipped.

Assuming now that the subscriber at the calling substation A initiates a call, he removes his receiver, thus closing a circuit lfor the line relay LR and ringing relay RI, traced from battery through the winding ot relay LR, conductor 80, through the substation, conductor 81 to ground through the winding of ringing relay RI. rlhe two relays LR and RI are thus energized in series. Assuming further that it is the subscriber at substation C that is wanted and his number is 15. the subscriber at substation now actuates his calling device to send tifteen impulses of current over the line by first sending ten impulses and then five, as is well understood, or any other combination of impulses to make the requisite number.

`contacts 4, 6 and 7,

construction. Upon the first denergization of relay LR, an energizing circuit for motor magnet MM is established, traced from batt'ery, through the Winding of motor magnet MM, conductor 82, normal Contact 83 of relay LR, conductor 84, normal contact 85 of switching relay SW, conductor 86, to ground at alternate contact 87 of ringing relay RI. The magnet MM upon energization causes the pawl 48 to engage a tooth of the ratchet 33, stepping the wipers 15, 17 and 18 into engagement with the first set of and the motor magnet MM is energized and denergized fifteen times due to the closing and opening of normal contact 83, and the wipers 15, 17 and 18 are stepped into engagement with the fifteenth set of contacts 4, 6 and '7 which are the contacts of the called substation C. Upon the first step of the wipers oil" normal, off-normal contacts ON assume their alternate positions and the closing of alternate contact 88 places a ground or busy potential upon the private normals 89 of the calling substation A, making it busy against any incoming calls.

After the subscriber at the calling substation A has sent the impulses, he depresses the key GK to impress ringing current upon the called subscribers line, and relay LR re mains energized while relay Rl is short circuited and falls back. Assuming that the called line is idle, the depression of the key GK brings about a series energizing circuitfor the switch relay SW and the switch relay SW of the individual switch D of the called line C, traced from battery through the lower winding of relay Si' l. conductor 90, normal contact 91 of primary off-normal contacts 0N', conductor 92, normal contact 93 of relay 14R/conductor 94. normal contact 95 of relay R1, conductor 96, Contact 1, wiper 15, conductor v97, upper winding of relay SW, conductor 98, alternate contact 99 of relay LR, normal contact 10() of relay RI (the said relay RI restoring when the key GK is depressed as it is shunted, the said shunt being traced from 0fround at alternate contact of the key G conductor 81 to ground through the winding of relay RI), conductor 101, conductor 102, to ground at alternate contact 88 of primary off-normal cont-acts ON. The closing of alternate contact 111 of switching relay SW closes a locking circuit for itself, traced from battery, through the lower winding of relay SW, alternate contact 111, conductor 86, to ground at alternate contact 87 of relav Rl. U on each actuation of the key GK. relay R restores for reasons as: aircady delill) scribed, and the opening of alternate contact 8T opens the circuit of relay SW, but an alternative circuit for relay SlV is closed during the denergization of relay RI, traced from battery` through the lower winding of relay Fill?, alternate contact 111, conductortiti, conductor 10i-l, alternate contact 101 of relay LR, conductors 105 and 102 to ground at alternate contact S8 of ottu normal contacts ON. Each depression of the key GK impresses ringing current upon the called line. due to the denergization of relay Rl upon each actuation of key GK, the ringing circuit being traced from the ungrounded pole of the generator G, alternate contact 10G of relay Sill', conductor 10T. normal contact 130 ot relay Rl, alternate contact 109 of relay SlV. wiper 18, conductor T. through the call bell and condenser of the called substation back through contact 6, wiper 1T. alternate contact 110 of relay Sll'. conductor 81, through relay RI to ground. The closing of alternate contact 112 of relay Sli' places a ground or busy potential upon the private contact 4 from ground at alternate contact H8 of off-normal contacts ON, cmiductors 102 aud 105, alternate contact 104 of relay LR. conductors 103 and 8G, alternate contact 112 of relay SlV, conductor 9T. wiper 15 to contact 4, thus preventing any other calling subscriber from engaging with the contacts of the called line.

lVhen the called subscriber at the substation C answers in response to his call bell, the removalof the receiver thereat closes an energizing circuit for the line relay LR and the ringing relay RI of the switch D associated with `the called line, from battery, through the Winding of relay LR', conductor 113. through the now closed contacts of the subst-ation switch hook, conductor 11-ito ground through the winding of relay RI'. The closing of alternate'contact 115 of relay RI closes a locking circuit for the switching relay Sl l' from battery throughl its alternate contact 116, conductor 117 to ground at alternate contact 115 of relay RI. The subscribers at substations A and ,C are now in conversational circuit, and the'talking circuit may be traced over the heavily marked conductors, the said conductors having the condensers K and K interposed.

Assuming now that the subscribers at substations A. and C have finished conversation, the calling subscriber A replacing his receiver upon the switch hook allows the relays R and LR to restore, due to the opening of the switch hook contacts, and the opening of contact. 8T of relay RI opens the locking circuit of switching relay SW', which relay restores to normal. The closing of normal contact 99 of relay LR and normal contact 100 of relay RI establishes an energizing circuit for motormagnet MM,

traced from battery, through the winding of magnet MM, its normal contact 120, conductor 121, alternate contact 122 of olf-normal contacts ON, conductor 123, normal contacts 99 and 100,

conductors

101 and 102 to ground at alternate contact 88 of ott-normal contacts ON. The magnet MM4 upon energization causes the Wipers 15, 17 and 18 to be stepped from the contacts it was engaging and the opening of its contact 120 opens the circuit of the magnet MM, allowing it to restore, and the closing of its contact 120 again energizes the magnet MM. The magnet MM is thus energized and deenergized, stepping the wipers 15, 17 and 18 until the arm 42 again engages the off-normal contacts ON, moving them back to their normal position, and the opening of contacts`88 and 122 of the said off-normal .contacts ON opens the energizing circuit of .magnet MM preventing further movement of the switch wipers 15, 17 and '18. The replacing of the receiver at the called substation C {opens the energizing circuit for relay RI and LR at the switch hook contacts, and relay RI restoring opens its alternate contact 115, allowing-the switching relay SlV to restore provided the calling subscriber has already hung u a, which places the apparatus of the switch associated with the called subscriber,'at normal. The apparatus used in establishing the above described connection is now at normal and is available for use in establishing other connections.

Assuming now that the called lineis busy, the operation/of 'the circuit is the same'as previously described-up to the timeI that the calling subscriber depresses lthe key- GK. It the wanted line is busy as a calling line, its private normals 4 will be grounded from the alternate contact 126 ofthe oit-normal contacts ON', while if busy, as a called line, its private normals will be roundedI from the ground extending throug the alternate contact of the switching relay STV of the switch of the calling line, as already described. The calling subscriber having selected .the contacts of the called line, now Adepresses the key GK. A. path extends from ground at the busy contact l, wiper 15 of s\vitchD, conductor 97, through the upper Winding of relay SW, conductor 98, alternate contact 99 of relay LR, normal contact 100 of relay RI, (the said relay being short circuited upon the depression of the key GK, as already described),

conductors

101 and 102 to ground at alternate contact 88 of off-normal contacts ON. Relay SlV does not energize-in this instance, due to its upper winding being grounded at both ends, and a busy signal is transmitted to the calling subscriber, traced from the busy signal. BB, normal Contact 109 of re lay SW, alternate contact 130 of relay RI (the said rela RI again energizing as soon as the key (ih is released), through the receiver of the calling subscriber at substation A, back over conductor 81 and through the winding of' relay RI to ground. The calling subscriber receiving the busy signal, now replaces his receiver and this act opens the circuit for relays RI and LR, bringing about the energization of the motor magnet MM, which magnet MM steps the wipers ahead as previously described, until they reach normal, when the switch is again available for establishing other connections.

lu describing my invention I have employed preferred circuit arrangements, but it is to bc understood that various changes may readily suggest themselves to those lskilled in the art, and I, therefore, do not desire to be limited to the exact arrangement shown and described, but aim to cover all such changes and modifications which come within the spirit and scope of the appended claims.'

lVhat I claim as new and desire to secure by United States Letters Patent, is:

l. A telephone system including a subscribers line, an automat-ic adding-type connector switch individual to said subscribers line controlled over the two sides of the subscribers line in series, a single row or level of bank contacts for said automatic switch, other subscribers lines terminating in said bank contacts, subscribercontrolled means for said switch for connecting said first subscribers line to any one of said other subscribers lines, subscriber-controlled means for ringing the called substation, and automatic means for moving said switch to normal position.

2. A telephone system including a subscribers telephone line, an automatic adding-type connector switch individual thereto and controlled over the two sides of the subscribers line in series, bank contacts for said switch, subscribers lines terminating in said bank contacts, step-by-ste means for said switch for connectin said rst sub-. scribers line to any of said ot er subscribers lines,'subscriber-controlled 'means for rin ing the called substation, and automatic means for operating said step-by-step means to move the wipers of said switch to a normal position.

3. A telephone system including a subscribers telephone line, an automat1c switch individual thereto, a pair of-line relays for said switch connected to said subscribers line, a Isingle level of bank contacts for said switch, other subscribers lines connected to said bank contacts, an impulse sending device for operating one only of said line relays to cause a connection to be 'established between said first subscribers line and one of said other subscribers lines, and subscriber-controlled means for maintaining said line relay energized and Jfor denergizing the said other line relay to signal the called subscriber.

4. A telephone system includin a subscribers telephone line. an automatic switch individual thereto, a. pair of line relays for said switch connected to said subscribers line, a single level of bank contacts for said switch, other subscribers lines connected to said bank contacts, an impulse sending device for operating one of said line relays to cause a connection to be established between said first subscribers line and one of said other subscribers lines, subscriber-controlled means for maintaining said line relay energized and for denergizing the said other line relay to signal the called subscriber, and subscriber-controlled means for denergizing both of said line relays, whereby said switch resumes a normal position.

5. A telephone system including a subscribers telephone line, an automatic switch individual thereto, a pair ot' line relays for said switch lconnected to said subscribers line, a single level of bank contacts for said switch, other subscribers lines connected to said .bank contacts, an impulse sending device for operating one of said line relay-s to cause a connection to be established between said *first subscribers line and one of said other subscribers lines, subscriber-controlled means for maintaining said line relay ener-- gized and for denergizing the said other line relay to signal the called subscriber, and automatic means for said switch, controllable by the denergization of Aboth the said line relays for advancing the wipers of said switchvto normal position.

6. A connector circuit including a telephone line, a pair of electro-magnets in series therewith; means for vibrating the first by digit impulses, while the second maintains its armature in operated position; circuit connections for holding the first in opera-ted position while the second retracts itsarmature; a test relay switched into circuit by said magnets; a source of ringing current connected in when said relay is in oneoperative position; a source'of busy current connected in when said relay 1s in another operative condition.

7. A connector circuit including a telephone line, a pair of electro-magnets in series therewith; means for vibrating the first by digit impulses, while the second maintains its armature in operated position; circuit connections for holding the first-in operated position'while the second retracts its armature; a test relay switched into circuit by said magnets; a called line; a test relay for said line in circuit with said first relay; a source of current connected to said circuit and energizing both said relays when the called lineis idle.

8. A calling and a called telephone line;

a connector for each line, said connectors having each a test relay in temporary circuit with each other; and calling line means for connecting a current source to said circuit. Y

9. A connector having a quick and a slow electroinagnet, the first retracting and the other holding its armature responsive to substation control; substation means to reverse said positions of said armatures; travel controlling mea-ns sensitive to the first armature relation; and test controlling means sensitive to the second armature relation.

10. A telephone system including a calling and a called line, each having a connector, said connectors temporarily switched together; a test relay foreach connector adapted to operate in circuit with 'one another when the called line is idle; and an ofi' normal contact of each connector controlling a circuit of its relay.

11; A telephone system including a call ing and a called line, each having a conncctor, said connectors temporarily switched together; a test relay f'or each connector adapted to operate in 4circuit with one another when the called line is idle; and two ofi" normal contacts of each connector controlling the circuit of its relay.

12 A telephone system including telephone lines; a connector, an off normal contact serving to place a busy potential on the private normal of said connector; means lfor connecting said contact to a wiper of ysaid connector to test the called line; a test relay with a winding in series between said contact and said wiper, and operating in a manner dependent on the electrical condition of an engaged called line contact for switching a connection t0 said wiper to render the called line busy.V

13. A connector 'for automatic exchanges including a relay adapted to be operated in series with the two limbs of a line or over one limb thereof; a called line; and a test relay for said connector to test the called line having a test winding controlled by said first relay and a locking Winding for said test relay. l

14. A connector for automatic exchanges including a relay adapted to be operated over the two limbs of the line or over one limb at the will of the subscriber; atest relay for said connector, circuit means con-` trolled by said first relay for controlling said test relay; and an off normal contact in the circuit of said test relay.

15. A connector for automatic exchanges including a relay adaptedto be operated over the two limbs of the line or over one limb at the will of the subscriber; a test relay for said connector, circuit means controlled by said first relayl for controlling said test relay; and two off normal contacts for said connector and a circuit'connection from each contact to Said test relay.

16. A connector for automatic exchanges including a relay adapted to -be operated over the two limbs of the line or over one limb at the will of thesubscriber; a test relay for said connector, circuit means .controlled by said first relay for controlling said test relay; means for switching said test relay tooperatively connect with the called line, an off normal contact controlled from the callin line, another ycontrolled from the calledlmc, the circuits of said test relay being` connected to both said contacts.

1T. A connector for automatic exchanges including a relay adapted to be operated over the two limbs of the line or over one limb at the will of the subscriber; a test relay for said' connector, circuit means controlled by said first relay for controlling said test relay; means for switching said test relay` to connect with thel called line, an ofi' normal contact controlled from the calling line, another controlled from the called line, the

circuits of said test relay being connected to both said contacts; and a talking circuit of said connector including normally open contacts of said test relay.

18. A connector for automatic exchanges including a relay adapted to be operated over the two limbs of the line or over one limb at the will of the subscriber; a test relay for said connector, circuit means controlled by said first relay for controlling said test relay; an ofi' normal contact in the circuit or said test relay; and ringing and busy back connections controlled by said test relay. f

19. A connector for automatic exchanges including a relay adapted to bel operated over the two limbs of the lineor overdone limb at the will of the subscriber.; a test relay `for said connector, circuit means controlled by said first relay for controlling said test relay; an ofi" normal contact in the circuit ot said test relay; a talking circuit of said connector including normally open contacts of said test relay; ringing and busy back connections controlled by said test relays.

20. Al connector for automatic exchanges including a relay adapted to be operated over the two limbs of the line or over one limb at the will of the subscriber; atest relay for said connector, circuit means controlled by said first relay for controlling said test relay; a slow release relay for said connector subject to substation control, said test relay when energizing lookin irst over a contact of said first mentione relayand then over a Contact of said`slow relay.

21. A connector for automatic exchanges including a relay Iadapted to be operated over the two limbs of the line or over one limb at the will of the subscriber; a test relay for said connector, circuit means controlled by said first relay for controlling said test relay; a slow relay for said connector subject to substation control, said slow relay also controlling said test relay; a called line and a relay therefor, means for energizing said test relay and said called line relay in series, said relays locking over a contact of said first mentioned relay and also over an independent locking circuit including a contact of said slow relay.

22. A connector t'or automatic exchanges, including a test relay. a slow relay subject to substation control and serving to operatively connect said test relay. a third relay, a locking circuit for said test relay. including a switch contact lot' said third relay, another locking circuit for Said test relay including a contact of said slow relay and means for successively closing said locking circuits.

E23. A connector including a test relay, an energizing circuit and two holding circuits for said relay. 'and switch means for closing said three circuits in succession.

2l. A connector including a relay, line switching contacts on Said relay, an energizing circuit and a locking circuit for said relay. and holding means to retain said relay in operated position after the establishment of said energizing circuit and until said locking circuit is completed.

25. An automatic telephone system including a pair ot' telephone lines connected to connectors respectively. said lines temporarily switched together, a test relay for each connector, and means for energizing both said test relays when the called line is tested.

26. An automatic telephone system including a pair ot' telephone lines provided with individual adding-type connectors, respectively. said lines being temporarily switched together, a relay t'or each connector, and means for energizing both ot' said relays when a connection is effected.

Signed by me at Chicago, county of Cook and State of Illinois, this 13th day 0f May. 1919.

HARRY H. IDE.