US918660A - Intercommunicating trunking system. - Google Patents

Description

L'. R. coRwIN'. GOMMUNIGATING TRUNKING SYSTEM. l APPLICATION HL2 Mu 9. 190s.

INTER Patented Apr wrmsssss:

` INVFNTOR:

1HE-Mamas PEIRRS co., wAsHlNaraN. n, c.

Y drawing, illustrating same.

dy Invention relates to Intercornmunicat- Unir srA"r Rs ATRNT ormoni.

RLMER R. CORWIN, ORCIIICAGQILLINOIS," AssIeNoR To CORwIN TELEPHONE MANUFAC- rIIRINe COMPANY, or CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

IN'rnRcoIi/IMUNICATING TRUNK'INCT SYSTEM.

Specification of Letters Patent.

Patented April ao, 1909.

Application filed May 9, 1908.l Serial No. 431,948.

To all whom 'it may concern; l

Be it known that I, ELMRR R.. CoRwIN, a citizen ofthe United States of America, residing at Chicago, in the county of Cook-and State of illinois, have invented a new and useful lntercommunicatingTrunking System, of which the following is a specii'ication, reference being hadV to the ,accompanying ing telephone systems and deals in particular withtrunking arrangements or such systems adapted to trunk with magneto exchanges.

rlhs principal Objects of my ,inventionare' to provide'improved trunking arrangements telephone systems and magneto exchanges; to provide improved means `for signaling the magneto exchange from the varionsfstations oi the iiitercommunicating telephone system,

to provide improved talking circuits between common battery intercommunicating telephone systems and magneto telephone systems; to provide improvedmeans for receiving and handling incoming trunk calls from a magneto exchange, in such an intercommunicating telephone system and to rovide other improvements in' a full-metallic common-battery intercommunicating telephone system having indicating ringing and,

be connected with any of the other stations on the system as desired, for conversation between any two parties on the system, without the intervention of the ordinary telephone central switchboard, such'connection also. permitting any of the other parties on the system to simultaneously converse with each other. At each station on the system is also provided switching mechanism associated withia central source of ringing current, whereby each of the parties on the system may ring any ofthe other stations as desired. to signal same for conversation. In addition to the above the system also provides switching mechanism and `suitable apparatus whereby any of the parties on the system ymay ca lly out to magneto centra-l exchange over'suitable trunklines, one ofthe stations on the system (called the attendants station) being provided with a signaling device on each` oi the trunk lines for receiving incoming trunk callsfrom the magneto central exchange7 and means whereby any oi' tho other stations of the system may be called to 1 respond to the incoming trunk calls. The accompanying drawing illustratesdiagrammatically a 'number of stations and trunk lines onV the system of my present in'- vention, in connection with suitable mechamsm and connections for operating and K Autilizingthe system. for trunking between intercommunieating'i Theapparatus at thevarious stations v 1, 2,

3, etc. iis included betweenlines f g, gi, i 7c,

etc. respectively. y Y,

Each of the stations on the system is provided With a plurality oi' push-button keys such as keys T, T2, H, l, 2, 3, etc., each` key being provided with a pair of spring contact' members 4 adaptedA to engage a pair of contact members 6 7, respectively, when the push-button 8 is depressed, and adapted to lock in this depressed osition so as to keepA the saidcontacts closed):l Each push-button switch or key, except the home keys H H, is

alsoprovided with a 'contact member'lO,z

adapted to engage contact member 7 when the push-button 8 is depressed past the locking position. All ofthe keys at any one station on the system are connected with a common locking mechanism whereby the depressions of any one oi the push-buttons 8 releases anyoi the other keys at this station which may be in locking osition, and allows same, to return' to norma position, each key being so constructed that it will return to its normal osition when the locking mechanism `is re eased. As there are known in the art several diiierent locking keys and banks ofkeys'v which` could be readily adapted for use in connection with this invention, it is not thought to' vbe necessary to herein describe, in detail, any articular locking lierein shown. In this connection it is believed to be suilicient to merely state that each oi' the keys shown n in the drawing locks ina position in which spring members 4 and 5 engagecontacts 6 and 7, respectively, 'and that eachkey, `eX- cept the home keys H H, is capable of, being Jfurther f depressed until contact 7 "engages oontact'lO, notv locking in this latter position lio but returning to the aforesald locking position when the pressure is removed from the button S.

The local lines of the intercommunicating telephone system are designated on the drawing by c, d and e, respectively, the trunk lines being designated by a and l), respectively. Each or' the keys at a station is adapted to connect the transmitter 19 and receiver 2O ot that station across the corresponding local lines of the system, or across the corresponding trunk lines of the system, each home key H being adapted to connect the home transmitter 19 and receiver 20 across the home line.

Each of the telephones on the system is provided with a ringer 11 which is normally connected to one limb of its home line through'suitable switch-hook contacts. The ringers 11 11 are all connected to one pole or the ringing battery 12 while the ringing contacts 10 10 of the various keys are all connected to the opposite pole of the rin-ging battery 12. When any one of the keys or a certain line is depressed to ringing position, itv closes the circuit of ringing battery 12 through the ringer 11 of the said line, as will be hereinafter traced, and thereby rings the ringer to signal the party at that station to the telephone.

Each of the trunk lines of the system is divided into two parts, a part a (or b) common to all of the local stations of the intercommunicating system, and a part A (or B) eX- tending to the ma neto exchange. The two parts of each trun line are inductively connected for talking purposes by a repeating coil 34 35 and condensers 17 and 18 connected in circuit with the respective sides'oic the repeating coil 34 35, so as to keep the magneto end of the trunk line separate from the common battery end of the trunk line. Each of the local lines c, d and c of the system, and each of the local portions a and Zi of the trunk lines, are supplied with talking current `from talking battery 14 over a pair of impedance coils 15 36 connected to the respective sides of each of the metallic lines. The condensers 1S 18 are for the purpose of keeping the circuits of battery 14 normally open across the corresponding trunk lines. The condensers 17 17 are for the purpose of allowing conversation to be carried on through the corresponding repeating coils 34 35, 34 35, but at the same time preventing ringing current sent from the magneto exchange, from flowing through the windings 34 34 of the corresponding repeating coils enough to shunt the corresponding ringers 16 16 and thereby render same unresponsive to the ringing current, each condenser 17 being or small capacity, preferably of one-half of a microfarad, for the purposes stated. The condensers 17 17 and 18 18 are connected in the middles of the corresponding windings 34 34 and 35 35, so as to properly balance the trunk lines. The ringer-s 16 1G are bridged across the corresponding trunk lines A and B to be rung from the magneto exchange to signal the attendant of the intercommunicating system to answer the incoming trunk calls. Each ot the trunk lines A and B is provided with a kick-coil for throwing the corresponding drop at the magneto exchange, to signal the exchange operator to answer an intercommunicating outgoing trunk call. One winding 42 ol each of the kick-coils is bridged across the corresponding trunk line A (or B), the other winding 43 ol" each kiekcoil being connected -lrom the pole of battery 12 to which ringers 11 11 are connected, to one limb of the local portion et the corresponding trunk line (t (or b). The depression o'll any one of the keys on a trunk line, to ringing position, closes the circuit ot battery 12 through the winding 43 of the corresponding kick-coil and thereby produces an impulse of current in the winding 43 which induces an impulse of current in the corresponding winding 42 and the magneto end ot the trunk line A (or B), and thereby throws the corresponding trunk-line drop at the magneto exchange.

To show how one party on the system calls another party on the system and how connection is made l'or conversation between these tvo parties, l will assume that the party at station 1 calls the party at station 3, and will trace the operations and connections neeessary to enable the party at sta.- tion 1 to converse with the party at station 3. lt will be understood that any party on the intercommunicating system may call and converse with another party on the system, in a manner similar to that next hereinbelow described, even ilI other stations on the system are busy; the ringing circuits having one individual conductor, and a common-rcturn, foreach ringer, and the talking circuits being metallic throughout. ln calling the party at station 3, the party at station l-.tirst dcpresses his push-button key 3 to the ringing position, that is, until contact 7 thereof cngages contact 1.0, and thereby closes a circuit 'lrorn ringing battery 12 through conductor 21, contacts 1() 7 ol key 3 at station 1,limb 2f. oi line e, contacts 41 40 at the switch-hook of station 3, ringer 11 o'll station 3, and conductor 23 back to battery 12. The current l'roni battery l2 now flowing through this circuit rings the ringer 11 at station 3. When the party at station 1` has thus rung station 3 sutliciently he releases his key 3 which returns to locking position, that is, to the position in which spring members 4 and 5 engage contacts 6 and 7, respectively, contacts 10 7 being now open, and then removes his rcceiver 2() from the switch-book 25 which bridges his transmitter 19 and receiver' 20, through conductors 29 and 3() oi station 1,

ll tl Y and through contacts 4 6 and 5 7' of key 3 at station 1, across the limbs 28 and22 of `line e.v

Conductors 29 and 3() extend to all ofthe spring members 4` and 5, respectively, o1 the several push-button keys or switches at this station. The party at station 3 answers his call by lifting his receiver 20 from the switchhook 25 which disconnects contacts 40 and 41 and connects contacts 26 and 27, and then depresseshis home key H' to locking position which bridges his transmitter 19 and receiver 20 across'the limbs22 and 23 o'l' his metallic line c. NovT the talking circuit is closed from transmitter 19 at station 1.,v

20, at station 1, back to transmitter 19 at` station 1. This talking circuit is fed Ywith current from talking battery 14 throughimpedance'coils 15 and 36 of line e.

high impedance and of low resistance conipared with the resistance of receiver 20, and

is provided as a shunt around receiver 20 so as to take most oi the direct-current supply flowing through the transmitter 19 and at the saine time allow receiver 20 to take approximatelyall of the ,talking currents 'passing through the transmitter 19. Thedirect current which supplies the transmitter 1.9 is thus shunted Yfrein thegreceiver 20 so that the latter will not become demagnetized or overmagnetized thereby. When the conversation between parties 1 and 3 is ycompleted these parties hang up their receivers on their respective switch-hooks, which opens the circuits 'of their talking sets at the respective switch-hooks and thereby stops the ilow of current from battery 14 over the aioretraced talking circuit between stations f1- and 3. Party 1 leaves his key 3 depressed untilhe desires to use his line again, either in communication With station 3 or With any 4of the other stations or trunk lines of the` system; The depressionl of any of the otherkeys at station 1, when` it is desired to again use the talking set at station 1, releasesfthe key 3 as hereinbefore stated. Party 3 alsoleaves his home key H depressed untilhe desires touse his talking set again,v his key H being restored by the depression ofany of his other,

keys, as tion 1. Y

`1f any of the parties of the intercommunieating system desires to make an, outgoing trunk call over a trunk line, as, for example, the party at station 2 calling out over trunk just stated in connection with staline a'A, he first depresses his trunk key (or T2) corresponding to the trunk line, to

locking position, which closes the circuit oi' The irn` pedance coil 31 at each of the stations is of ringing battery 1.2 through conductor 23,

VWinding' 43 of the kick-coil associated with Vfrom battery 12 through this circuit causes Winding 43 of the kick-coil toinduce an inipulse oi Vcurrent in the Winding 42 oi the kickcoil, which latter impulse ol' current traverses the trunk line A leading to the magneto exchange and throws the corresponding trunkline drop at the magneto exchange. Now the calling party at station 2 releasesV his trunk key which returns to locking position so that contacts 4 and 5 thereoiI engage contacts 6 and 7, respectively, and then removes his telephone receiver 2() 'from the switchhook 25 Which connects `contacts 26 and 27 and thereby bridges his transmitter 19 and receiver `2() through conductors 29 and 30 ol' his station, and contacts 4 6 and 5 7 oi' his depressed trunk key, across the limbs 32 33 of the `trunk line a for conversation with the magneto exchange.V The conversation may now be carried on Withv the party connected through the magneto exchange, over the trunk line a A, through the repeating coil 34 35 associated With the trunk line. The transmitter 19 at station 2 is su plied With talking current from battery'14 through impedance coils 15 and 36 of the trunk line to Which sta tion 2 is connected, limbs 32 and 33 oil the trunk line, contacts 6 4 and 7 5 o1' the depressed trunk key,` conductors 29 and 30,01'

station 2, and contacts 27 26 and impedance coil 31 of station 2. When the conversation is completed the party at station 2 hangs up his receiver 20 `en the switch-hook 25 and thereby breaks the circuit oll battery 14 through his telephone. The party at station 2 may now depress the depressed trunk key from locking position to ringing position and thereby cause the kick-coil 42 43 to throw the disconnect 'drop at the magneto exchange, as herein-before described in connec-V tion With'the line drop at the magneto exchange. The party at station 2'leaves his trunk key `depressed until he desires to use histalkine` set a V'ain his trunk ke bein restored to normal position by the depression of any ol his other keys, as stated above iny connection. Withfstations 1 and 3.

VJhen the operator at the magneto exchange desires a connection With a station of of the contacts of the key are open.

29 and 30 of station 1 and contacts 4 6 and 5 7 of the depressed trunk key at station 1, across the limbs 33 of the trunk line (L (er Zi). Now the attendant conversos With the party connected from the magneto exchange over the trunk line and learns trom him the station of the intercommunicating system with which communication is desired. Assuming this latter station to be station 2 oi the intercommunicating system, the attendant calls station 2 by depressing his key 2, at station 1, to ringing position which signals the party at station 2 by closing the circuit of ringing battery 12 through conductor 21, contact 10 7 or key 2 at station 1, limb 22 of line d, contacts 11 10 of station 2, ringer 11 orn station 2, and conductor 23 back to battery 12. Current flowing through this circuit rings the ringer 11 of station 2 Which signals the party at this station. When the attendant depresses his key 2 to signal the party at station 2 he automatically releases his depressed trunk key T (or T2) and restores same to normal position in which position all Key 2 of station 1, being now released and moving to locking position, bridges the telephone transmitter 19 and receiver 20 of station 1 across the limbs 23 22 of line d, as hereinbefore described. When the party at station 2 answers the signal oi his ringer 11, he depresses his heine key H to locking position and removes his receiver 2O from the switchhook 25 which bridges his transmitter 1Q and receiver 2O across the limbs 28 22 of his line d, as hereinbefore described. The attendant now converses with the party at station 2 and instructs him to make connection With the calling trunk line c (or t) to answer the incoming trunk call. The transmitters 19 19 of stations 1 and 2 are now supplied with talking current from battery 14 through impedance coils 15 and 36 of line d, in a manner similar to that hereinbefore described. 'The attendant now hangs his receiver 2O upon the switch-hook 25 which breaks his transmitter bridge across the limbs et line d as Will be readily understood. New the party at station 2 depresses his trunk key ll (or T2) corresponding' to the calling trunk line, Which releases iis home key H and thereby bridges his transmitter 19 and receiver 20 through conductors 29 and 30 ol station 2, and contacts e1 6 and 5 7 of the depressed trunk key at station 2, across the limbs 32 33 oi the calling trunk line. Non' the party at station 2 may converse With the party Who is connected through the magneto central exchange and the trunk line A a (or B b), through the medium of repeating` coil 34 35 of the corresponding trunk line, transmitter 19 of station 2 being supplied with talking current from battery 14 through impedance coils 15 and 36 oi the calling trunk line, as hereinbefore described, Then the conversation is completed and the party at station 2 hangs his receiver 2O on the switch-hook 25 he breaks the bridge of his talking set across the trunk line with which his talking set is connected, and thereby stops the ilow of current from battery 14 through his transmitter 1E). The party at station 2 may give a disconnect signal to the magneto excl'iange by depressing his depressed trunk key to ringing position which sends an impulse of current .trom battery 12 through Winding 13 ol the corresponding kick-coil, and thus induce :in impulse of current through the winding 42 olI the said kick-coil which current traverses the corresponding trunk line A (or B) and throws the disconnect drop at the magneto exchange, hereinbe'fore described. rl`he party at station 2 leaves his trunk key depressed to locking position until he desires to use his talking set again when the depression of any of the other keys at his station releases the depressed trunk key.

It will be readily seen that the ringing and talking keys of this system are self-indicating, that is, they indicate the party with Whom conversation was last had, or, in the case of calling a party who does not respond, they indicate the station with which communication is desired, so that the calling party may again readily depress the proper key to ringing position to signal the called party a second time.

l do not Wish to limit this invention to all of the particular details herein shown, as many modi'lications ol saine may be made Without departing from the scope of the appended claims.

Viral; l claim my invention is:

1. 11n interconn'nunicating tcleplnme system having a plurality of local lilies common to a plurality ci stations, a trunk line extend.- ing from the intereoinmunicating system to a magnetic exchange, a repeating coil inductiyely connecting one oi the said. local lines with the trunk line whereby conversation may be carried on from the various said stations over the trunk line, a kick-coil having one winding bridged across the trunk line at the interconnnunicating sjysteni, and means at the Various said stations for causing the kick-coil to throw a drop on the trunk line at the magneto exchange.

2. An intereonnnnnicat'ii1g telephone system h I ying a plurality o1a local common-battery 1ines common to a plurality of stations, a trunk lino extending lrom thc interconnnunicating system to a magneto exchange, a repeating coil inductively connecting one ol the local lines with the trunk line for talking purposes whereby the comn'uiii-battery local line is kopt separate from the magneto trunk line, a kick-coil having its primary winding connected. with the interconnnunicating system and its secondary Winding bridged across the trunk line, and means for sending an iin- Al l) pulse of current through the primary of the kick-coil to induce an impulse of current in the secondary of the kick-coil and thetrunk line, to throw a drop connected with the trunk line at the magneto exchange.

3. An intercommunicating telephone system having a plurality of local lines common to a plurality of stations, a trunk line extending from the intercommunicating system to a magneto exchange, a repeating coil inductively connecting one of the lo'cal lines with the trunk line for talking purposes, a kickcoil associated with the trunk line at the intercommunicating system for throwing a drop connected with the trunk line at the magneto exchange, and a condenser in series with the trunk-line side of the repeating coil whereby any considerable portion of the impulse of current produced in the ltrunk line by the kick-coil is kept from flowing through the repeating coil.

4. An intercommunicating telephone system having a plurality of local lines common to plurality of stations, a trunk line extending to a magneto exchange, a repeating coil inductively connecting one of the local lines with the trunk line for talking purposes, a pair of condensers in series with the respective windings of the repeating coil, kick-coil at the intercommunicating system having its Vsecondary bridged across the trunk line, and means for causing the kickcoil to send an impulse of current over the trunk line to throw a drop at the magneto exchange. v

5. An intercommunicating telephone system having a plurality of local lines common to a plurality of stations, a trunk line extending from the intercommunicating system to a magneto exchange, a kick-coil Vhaving its secondary bridged across the trunk line at the intercommunicating system, a suitable source of current at the intercommunicating system, and suitable ringing keys at the respective stations of the intercommunicating system whereby a party at any oi the vsaid stations m y send an impulse oi current through the kick-coil to cause the latterv toA throw a drop associated. with the trunk line at the magneto exchange.

5. An intercommunicating telephone systeni having a plurality of local lines common to a plurality of stations, a source oic talking current for the local lines, impedances feeding talking current from the said. source to the various local lines, a trunk line extending from the intercommunicating system to a magneto exchange, a repeating coil inductively connecting one of the local lines with the trunk line for talking purposes, a pair of condensers connected. in` series with the respective windings of the repeating coil, a kickcoil at the intercommunicating system having its secondary winding bridged across the trunk line, ringing and talking keys at each of the stations of the intercommunicating system, a source of ringing current associated with the intercommunicating system, and means whereby a Vparty at any of the said stations may send an impulse of ringing current through the kick-coil to cause the latter to throw a drop connected with the trunk line at the magneto exchange.

' 7. An intercommunicating telephone system having a plurality of local lines common to a plurality of stations, a trunk line extending from the intercommunicating system to a magneto exchange, a ringer bridged across the trunk line at the intercommunicating system whereby the operator at the magneto exchange may signal a party at the intercommunicating system, a re eating coil inductively connecting one o the said local lines with the trunk line for talking purposes, and a condenser connected in series with the trunk-line side of the repeating coil whereby any considerable portion of the ringing current sent from the magneto exchange toring the said ringer is prevented from flowing through the repeating coil.

8. n intercommunicating telephone system having a local line common to a plurality of stations, a trunk line extending from the intercommunicating system to a magneto exchange, a re eating coil inductively connecting the said ocal line with the trunk line for talking purposes,'a condenser in circuit with the trunk-line side of the repeating coil to permit talking currents to pass through the repeating coil, but being of small enough capacity to prevent any considerable amount of signahng current from passing through the repeating coil, a ringer bridged across the trunk line at the intercommunicating system for receiving incoming trunk calls, and a kick-coil at the intercommunicating system, the secondary of which is bridged across the trunk line whereby a party at the intercommunicating system may cause an impulse of current to be sent over the trunk line to throw a drop connected with the trunk line at the magneto exchange.

9. In a telephone system, a trunk line and a local line inductively connected for conversation by a repeating coil, a condenser of small capacity in series with a winding of the repeating coil whereby any considerable quantity of signaling current is prevented from passing through the repeating coil, a kick-coil associated with the trunk line at the local line whereby an impulse of current may be sent over the trunk line for signaling from the local line to an exchange, and a ringer associated with the trunk line at the local line'for receiving signals sent to the local line over the trunk line.

10. An intercommunicating telephone system having a plurality of local lines common to a plurality of stations, one of which stations is designated an attendants station, a trunk line extendingfrom the intercommunicating system to a magneto exchange, a repeating coil inductively connecting one of the local lines with the trunk line for talking ism at the attendants station whereby the attendant may signal any of the other stations of the intercommunicating system to answer an incoming trunk call, and suitable mechanism at the Various stations of the intercommunicating system whereby a party at any of the stations thereof may connect his telephone set with the last mentioned local line for conversation over the trunk line.

1l. In a telephone system, a trunk line, a local line extending to a plurality of stations of an intercommunicating system, a repeating coil inductiyely connecting the trunk line with the local line for conversation, a kick-coil associated with the trunk line at the local line, means at each of the Said stations controlling the kick-coil whereby an impulse of current may be sent over the trunk line from any of the said stations, 'for signaling from the local line to an exchange, and a signaling device associated with the trunk line at the local line for receiving signals sent to the local line over the trunk line.

l2. In a telephone system, a trunk line, a local line extending to a plurality of stations of an intercommunicating system7 a repeating coil inductively connecting the trunk line with the local line for conversation, a condenser of small capacity in series with a winding of the repeating coil whereby any considerable quantity of signaling current is pre- Vented from passing through the repeating coil, and a signaling device bridged across the trunk line at the local line for receiving signals sent to the local line over the trunk line.

18. In a telephone system, a trunk line, a local line extending to a plurality of stations of an intercommunicating system, a repeating coil inductively connecting the trunk line with the local line for conversation, a condenser of small cal'iacity in series with a winding of the repeating coil whereby any considerable quantity of signaling current is prevented from passing through the repeating coil, a kick-coil associated with the trunk line at the local line, and means at each of the said stations controlling the kick-coil whereby an impulse ol current may be sent over thc trunk line from any of the said stations, for signaling from the local line to an exchange.

14. An interior telephone system including a plurality of stations, a trunk line leading to an exchange, a switching key at an interior station being adapted to have at least two operating positions, in one of which it is adapted to connect an interior system ,with said trunk line, a signal device at the exchange end oi the trunk linc adapted to re` spond to impulses of current, a primary kiel: coil circuit which is closed by said switching key when occupying a diil'erent operating position, and a secondary kiek coil circuit in inductive relation with said primary kiekI coil circuit and including the signal device at the exchange end of said trunk line.

As inventor of' the foregoing l hereunto subscribe my name, in the presen e of two subscribing witnesses, this (ith daiif May, 1908.

ELME t It. COlWlN.

YVitnesses Y FREDERICK li. PARKER, FRANK J. RYAN.

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